/src/bind9/lib/dns/zone.c

Source
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <errno.h>
#include <inttypes.h>
#include <stdbool.h>

#include <isc/async.h>
#include <isc/atomic.h>
#include <isc/file.h>
#include <isc/hash.h>
#include <isc/hex.h>
#include <isc/list.h>
#include <isc/log.h>
#include <isc/loop.h>
#include <isc/md.h>
#include <isc/mutex.h>
#include <isc/netmgr.h>
#include <isc/os.h>
#include <isc/overflow.h>
#include <isc/random.h>
#include <isc/ratelimiter.h>
#include <isc/refcount.h>
#include <isc/result.h>
#include <isc/rwlock.h>
#include <isc/serial.h>
#include <isc/stats.h>
#include <isc/stdtime.h>
#include <isc/strerr.h>
#include <isc/string.h>
#include <isc/thread.h>
#include <isc/tid.h>
#include <isc/timer.h>
#include <isc/tls.h>
#include <isc/util.h>

#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/callbacks.h>
#include <dns/catz.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/dlz.h>
#include <dns/dnssec.h>
#include <dns/dsync.h>
#include <dns/journal.h>
#include <dns/kasp.h>
#include <dns/keydata.h>
#include <dns/keymgr.h>
#include <dns/keytable.h>
#include <dns/keyvalues.h>
#include <dns/master.h>
#include <dns/masterdump.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/notify.h>
#include <dns/nsec.h>
#include <dns/nsec3.h>
#include <dns/opcode.h>
#include <dns/peer.h>
#include <dns/private.h>
#include <dns/rcode.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/remote.h>
#include <dns/request.h>
#include <dns/resolver.h>
#include <dns/rriterator.h>
#include <dns/skr.h>
#include <dns/soa.h>
#include <dns/ssu.h>
#include <dns/stats.h>
#include <dns/time.h>
#include <dns/tsig.h>
#include <dns/ttl.h>
#include <dns/unreachcache.h>
#include <dns/update.h>
#include <dns/xfrin.h>
#include <dns/zone.h>
#include <dns/zonefetch.h>
#include <dns/zonemgr.h>
#include <dns/zoneproperties.h>
#include <dns/zoneverify.h>
#include <dns/zt.h>

#include <dst/dst.h>

#include "zone_p.h"

/*%
 * Ensure 'a' is at least 'min' but not more than 'max'.
 */
#define RANGE(a, min, max) (((a) < (min)) ? (min) : ((a) < (max) ? (a) : (max)))

#define NSEC3REMOVE(x) (((x) & DNS_NSEC3FLAG_REMOVE) != 0)

/*%
 * Key flags
 */
#define REVOKE(x)  ((dst_key_flags(x) & DNS_KEYFLAG_REVOKE) != 0)
#define KSK(x)     ((dst_key_flags(x) & DNS_KEYFLAG_KSK) != 0)
#define ADT(x)     ((dst_key_flags(x) & DNS_KEYFLAG_ADT) != 0)
#define ZONEKEY(x) ((dst_key_flags(x) & DNS_KEYOWNER_ZONE) != 0)
#define ID(x)    dst_key_id(x)
#define ALG(x)     dst_key_alg(x)

/*%
 * KASP flags
 */
#define KASP_LOCK(k)                \
  if ((k) != NULL) {          \
    LOCK(&((k)->lock)); \
  }

#define KASP_UNLOCK(k)                \
  if ((k) != NULL) {            \
    UNLOCK(&((k)->lock)); \
  }

typedef struct dns_stub dns_stub_t;
typedef struct dns_load dns_load_t;
typedef struct dns_asyncload dns_asyncload_t;

#ifdef ENABLE_AFL
extern bool dns_fuzzing_resolver;
#endif /* ifdef ENABLE_AFL */

/*%
 * Key file I/O lock pool.
 */
typedef struct dns_keymgmt_bucket {
  isc_mutex_t lock;
  uint8_t __padding[ISC_OS_CACHELINE_SIZE -
        sizeof(isc_mutex_t) % ISC_OS_CACHELINE_SIZE];
} dns_keymgmt_bucket_t;

static dns_keymgmt_bucket_t keymgmt_buckets_g[1024];

#define zonediff_init(z, d)                \
  do {                               \
    dns__zonediff_t *_z = (z); \
    (_z)->diff = (d);          \
    (_z)->offline = false;     \
  } while (0)

/* Flags for zone_load() */
typedef enum {
  DNS_ZONELOADFLAG_NOSTAT = 0x00000001U, /* Do not stat() master files */
  DNS_ZONELOADFLAG_THAW = 0x00000002U,   /* Thaw the zone on successful
            * load. */
} dns_zoneloadflag_t;

/*%
 *  dns_stub holds state while performing a 'stub' transfer.
 *  'db' is the zone's 'db' or a new one if this is the initial
 *  transfer.
 */

struct dns_stub {
  unsigned int magic;
  isc_mem_t *mctx;
  dns_zone_t *zone;
  dns_db_t *db;
  dns_dbversion_t *version;
  atomic_uint_fast32_t pending_requests;
};

/*%
 *  Hold load state.
 */
struct dns_load {
  dns_zone_t *zone;
  dns_db_t *db;
  isc_time_t loadtime;
  dns_rdatacallbacks_t callbacks;
};

/*%
 * Hold state for an asynchronous load
 */
struct dns_asyncload {
  dns_zone_t *zone;
  unsigned int flags;
  dns_zt_callback_t *loaded;
  void *loaded_arg;
};

/*
 * These can be overridden by the -T mkeytimers option on the command
 * line, so that we can test with shorter periods than specified in
 * RFC 5011.
 */
#define HOUR  3600
#define DAY   (24 * HOUR)
#define MONTH (30 * DAY)
unsigned int dns_zone_mkey_hour = HOUR;
unsigned int dns_zone_mkey_day = DAY;
unsigned int dns_zone_mkey_month = MONTH;

#define SEND_BUFFER_SIZE 2048

static void
zone_timer_set(dns_zone_t *zone, isc_time_t *next, isc_time_t *now);

static void
cancel_refresh(dns_zone_t *);
static void
zone_debuglogc(dns_zone_t *zone, isc_logcategory_t category, const char *me,
         int debuglevel, const char *fmt, ...);
static void
zone_debuglog(dns_zone_t *zone, const char *, int debuglevel, const char *msg,
        ...) ISC_FORMAT_PRINTF(4, 5);
static void
dnssec_log(dns_zone_t *zone, int level, const char *fmt, ...)
  ISC_FORMAT_PRINTF(3, 4);

typedef struct nsec3param nsec3param_t;

static void
queue_xfrin(dns_zone_t *zone);
static isc_result_t
update_one_rr(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
        dns_diffop_t op, dns_name_t *name, dns_ttl_t ttl,
        dns_rdata_t *rdata);
static void
zone_unload(dns_zone_t *zone);
static void
zone_expire(dns_zone_t *zone);
static void
zone_refresh(dns_zone_t *zone);
static void
zone_iattach(dns_zone_t *source, dns_zone_t **target);
static void
zone_idetach(dns_zone_t **zonep);
static isc_result_t
zone_replacedb(dns_zone_t *zone, dns_db_t *db, bool dump);
static void
zone_attachdb(dns_zone_t *zone, dns_db_t *db);
static void
zone_detachdb(dns_zone_t *zone);
static void
zone_catz_enable(dns_zone_t *zone, dns_catz_zones_t *catzs);
static void
zone_catz_disable(dns_zone_t *zone);
static isc_result_t
zone_postload(dns_zone_t *zone, dns_db_t *db, isc_time_t loadtime,
        isc_result_t result);
static void
zone_needdump(dns_zone_t *zone, unsigned int delay);
static void
zone_shutdown(void *arg);
static void
zone_loaddone(void *arg, isc_result_t result);
static isc_result_t
zone_startload(dns_db_t *db, dns_zone_t *zone, isc_time_t loadtime);
static void
zone_namerd_tostr(dns_zone_t *zone, char *buf, size_t length);
static void
zone_schedule_inline_sync(dns_zone_t *zone, inline_sync_phase_t state);
static void
refresh_callback(void *arg);
static void
stub_callback(void *arg);
static void
queue_soa_query(dns_zone_t *zone);
static void
soa_query(void *arg);
static void
ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset, dns_stub_t *stub);
static int
message_count(dns_message_t *msg, dns_section_t section, dns_rdatatype_t type);
static void
checkds_cancel(dns_zone_t *zone);
static void
checkds_find_address(dns_checkds_t *checkds);
static void
checkds_send(dns_zone_t *zone);
static void
checkds_createmessage(dns_zone_t *zone, dns_message_t **messagep);
static void
checkds_done(void *arg);
static void
checkds_send_tons(dns_checkds_t *checkds);
static void
checkds_send_toaddr(void *arg);
static isc_result_t
zone_dump(dns_zone_t *, bool);
static void
rss_post(dns_zone_t *zone, nsec3param_t *np);
static void
zone_process_maintenance_request(dns_zone_t *zone);

static isc_result_t
zone_get_from_db(dns_zone_t *zone, dns_db_t *db, unsigned int *nscount,
     unsigned int *soacount, uint32_t *soattl, uint32_t *serial,
     uint32_t *refresh, uint32_t *retry, uint32_t *expire,
     uint32_t *minimum, unsigned int *errors);

static void
forward_callback(void *arg);
static void
zone_saveunique(dns_zone_t *zone, const char *path, const char *templat);
static void
zone_maintenance(dns_zone_t *zone);

static void
inline_sync_run(dns_zone_t *zone);
static void
inline_sync_resume(dns_zone_t *zone);
static void
zone_clear_inline_sync(dns_zone_t *zone);
static void
inline_secure_bootstrap(dns_zone_t *zone);
static isc_result_t
secure_db_create_from_raw(dns_zone_t *zone, dns_db_t *rawdb, dns_db_t **dbp);
static void
zone_notify(dns_zone_t *zone, isc_time_t *now);
static void
zone_notifycds(dns_zone_t *zone);
static void
dump_done(void *arg, isc_result_t result);
static isc_result_t
zone_signwithkey(dns_zone_t *zone, dst_algorithm_t algorithm, uint16_t keyid,
     bool deleteit, bool fullsign);
static isc_result_t
delete_nsec(dns_db_t *db, dns_dbversion_t *ver, dns_dbnode_t *node,
      dns_name_t *name, dns_diff_t *diff);
static void
zone_rekey(dns_zone_t *zone);
static dns_ttl_t
zone_nsecttl(dns_zone_t *zone);
static void
zone_journal_compact(dns_zone_t *zone, dns_db_t *db, uint32_t serial);
static isc_result_t
zone_journal_rollforward(dns_zone_t *zone, dns_db_t *db, bool *needdump,
       bool *fixjournal);
#define ENTER zone_debuglog(zone, __func__, 1, "enter")

static const unsigned int dbargc_default = 1;
static const char *dbargv_default[] = { ZONEDB_DEFAULT };

#define DNS_ZONE_JITTER_ADD(a, b, c)                                         \
  do {                                                                 \
    isc_interval_t _i;                                           \
    uint32_t _j;                                                 \
    _j = (b) - isc_random_uniform((b) / 4);                      \
    isc_interval_set(&_i, _j, 0);                                \
    if (isc_time_add((a), &_i, (c)) != ISC_R_SUCCESS) {          \
      dns_zone_log(zone, ISC_LOG_WARNING,                  \
             "epoch approaching: upgrade required: " \
             "now + %s failed",                      \
             #b);                                    \
      isc_interval_set(&_i, _j / 2, 0);                    \
      (void)isc_time_add((a), &_i, (c));                   \
    }                                                            \
  } while (0)

#define DNS_ZONE_TIME_ADD(a, b, c)                                           \
  do {                                                                 \
    isc_interval_t _i;                                           \
    isc_interval_set(&_i, (b), 0);                               \
    if (isc_time_add((a), &_i, (c)) != ISC_R_SUCCESS) {          \
      dns_zone_log(zone, ISC_LOG_WARNING,                  \
             "epoch approaching: upgrade required: " \
             "now + %s failed",                      \
             #b);                                    \
      isc_interval_set(&_i, (b) / 2, 0);                   \
      (void)isc_time_add((a), &_i, (c));                   \
    }                                                            \
  } while (0)

#define DNS_ZONE_TIME_SUBTRACT(a, b, c)                                      \
  do {                                                                 \
    isc_interval_t _i;                                           \
    isc_interval_set(&_i, (b), 0);                               \
    if (isc_time_subtract((a), &_i, (c)) != ISC_R_SUCCESS) {     \
      dns_zone_log(zone, ISC_LOG_WARNING,                  \
             "epoch approaching: upgrade required: " \
             "isc_time_subtract() failed");          \
      isc_interval_set(&_i, (b) / 2, 0);                   \
      (void)isc_time_subtract((a), &_i, (c));              \
    }                                                            \
  } while (0)

struct nsec3param {
  dns_rdata_nsec3param_t rdata;
  unsigned char data[DNS_NSEC3PARAM_BUFFERSIZE + 1];
  unsigned int length;
  bool nsec;
  bool replace;
  bool resalt;
  bool lookup;
  ISC_LINK(nsec3param_t) link;
};
typedef ISC_LIST(nsec3param_t) nsec3paramlist_t;

#define OLD_SIGNING_RECORD_SIZE 5
#define SIGNING_RECORD_SIZE 7

typedef enum zone_maintenance_request_type {
  zone_maintenance_request_setnsec3param,
  zone_maintenance_request_keydone,
  zone_maintenance_request_setserial,
} zone_maintenance_request_type_t;

typedef struct zone_maintenance_request {
  ISC_LINK(struct zone_maintenance_request) link;
  zone_maintenance_request_type_t type;
  union {
    nsec3param_t nsec3param;
    struct {
      bool all;
      unsigned char data[SIGNING_RECORD_SIZE];
    } keydone;
    struct {
      uint32_t serial;
    } setserial;
  } u;
} zone_maintenance_request_t;

struct stub_cb_args {
  dns_stub_t *stub;
  dns_tsigkey_t *tsig_key;
  uint16_t udpsize;
  unsigned int connect_timeout;
  unsigned int timeout;
  bool reqnsid;
};

struct stub_glue_request {
  dns_request_t *request;
  dns_name_t name;
  struct stub_cb_args *args;
  bool ipv4;
};

/*%
 * Increment resolver-related statistics counters.  Zone must be locked.
 */
static void
inc_stats(dns_zone_t *zone, isc_statscounter_t counter) {
  if (zone->stats != NULL) {
    isc_stats_increment(zone->stats, counter);
  }
}

/***
 ***  Public functions.
 ***/

void
dns_zone_create(dns_zone_t **zonep, isc_mem_t *mctx, isc_tid_t tid) {
  isc_time_t now;
  dns_zone_t *zone = NULL;

  REQUIRE(zonep != NULL && *zonep == NULL);
  REQUIRE(mctx != NULL);

  now = isc_time_now();
  zone = isc_mem_getx(mctx, sizeof(*zone),
          ISC_MEM_ALIGN(ISC_OS_CACHELINE_SIZE));
  *zone = (dns_zone_t){
    .masterformat = dns_masterformat_none,
    .journalsize = -1,
    .rdclass = dns_rdataclass_none,
    .type = dns_zone_none,
    .refresh = DNS_ZONE_DEFAULTREFRESH,
    .retry = DNS_ZONE_DEFAULTRETRY,
    .maxrefresh = DNS_ZONE_MAXREFRESH,
    .minrefresh = DNS_ZONE_MINREFRESH,
    .maxretry = DNS_ZONE_MAXRETRY,
    .minretry = DNS_ZONE_MINRETRY,
    .checkdstype = dns_checkdstype_yes,
    .zero_no_soa_ttl = true,
    .idlein = DNS_DEFAULT_IDLEIN,
    .idleout = DNS_DEFAULT_IDLEOUT,
    .maxxfrin = MAX_XFER_TIME,
    .maxxfrout = MAX_XFER_TIME,
    .sigvalidityinterval = 30 * 24 * 3600,
    .sigresigninginterval = 7 * 24 * 3600,
    .statlevel = dns_zonestat_none,
    .signatures = 10,
    .nodes = 100,
    .privatetype = (dns_rdatatype_t)0xffffU,
    .rpz_num = DNS_RPZ_INVALID_NUM,
    .requestixfr = true,
    .ixfr_ratio = 100,
    .requestexpire = true,
    .updatemethod = dns_updatemethod_increment,
    .tid = tid,
    .notifytime = now,
    .newincludes = ISC_LIST_INITIALIZER,
    .checkds_requests = ISC_LIST_INITIALIZER,
    .signing = ISC_LIST_INITIALIZER,
    .nsec3chain = ISC_LIST_INITIALIZER,
    .maintenance_queue = ISC_LIST_INITIALIZER,
    .forwards = ISC_LIST_INITIALIZER,
    .statelink = ISC_LINK_INITIALIZER,
  };
  dns_remote_t r = {
    .magic = DNS_REMOTE_MAGIC,
  };

  isc_mem_attach(mctx, &zone->mctx);
  isc_mutex_init(&zone->lock);
  ZONEDB_INITLOCK(&zone->dblock);

  isc_refcount_init(&zone->references, 1);
  isc_refcount_init(&zone->irefs, 0);
  dns_name_init(&zone->origin);

  zone->primaries = r;
  zone->parentals = r;
  zone->alsonotify = r;
  zone->cds_endpoints = r;
  zone->defaultkasp = NULL;
  ISC_LIST_INIT(zone->keyring);

  dns_notifyctx_init(&zone->notifysoa, dns_rdatatype_soa);
  dns_notifyctx_init(&zone->notifycds, dns_rdatatype_cds);

  isc_stats_create(mctx, &zone->gluecachestats,
       dns_gluecachestatscounter_max);

  zone->magic = ZONE_MAGIC;

  /* Must be after magic is set. */
  dns_zone_setdbtype(zone, dbargc_default, dbargv_default);

  *zonep = zone;
}

static void
clear_keylist(dns_dnsseckeylist_t *list, isc_mem_t *mctx) {
  ISC_LIST_FOREACH(*list, key, link) {
    ISC_LIST_UNLINK(*list, key, link);
    dns_dnsseckey_destroy(mctx, &key);
  }
}

void
dns__zone_free(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(!LOCKED_ZONE(zone));
  REQUIRE(zone->timer == NULL);

  dns_zone_unloadplugins(zone);

  isc_refcount_destroy(&zone->references);
  isc_refcount_destroy(&zone->irefs);

  /*
   * Managed objects.  Order is important.
   */
  if (zone->request != NULL) {
    dns_request_destroy(&zone->request); /* XXXMPA */
  }
  INSIST(zone->statelist == NULL);
  INSIST(zone->view == NULL);
  INSIST(zone->prev_view == NULL);

  /* Unmanaged objects */
  ISC_LIST_FOREACH(zone->maintenance_queue, request, link) {
    ISC_LIST_UNLINK(zone->maintenance_queue, request, link);
    isc_mem_put(zone->mctx, request, sizeof(*request));
  }

  ISC_LIST_FOREACH(zone->signing, signing, link) {
    ISC_LIST_UNLINK(zone->signing, signing, link);
    dns_db_detach(&signing->db);
    dns_dbiterator_destroy(&signing->dbiterator);
    isc_mem_put(zone->mctx, signing, sizeof *signing);
  }

  ISC_LIST_FOREACH(zone->nsec3chain, nsec3chain, link) {
    ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain, link);
    dns_db_detach(&nsec3chain->db);
    dns_dbiterator_destroy(&nsec3chain->dbiterator);
    isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
  }

  ISC_LIST_FOREACH(zone->includes, include, link) {
    ISC_LIST_UNLINK(zone->includes, include, link);
    isc_mem_free(zone->mctx, include->name);
    isc_mem_put(zone->mctx, include, sizeof *include);
  }

  ISC_LIST_FOREACH(zone->newincludes, include, link) {
    ISC_LIST_UNLINK(zone->newincludes, include, link);
    isc_mem_free(zone->mctx, include->name);
    isc_mem_put(zone->mctx, include, sizeof *include);
  }

  zone_clear_inline_sync(zone);
  INSIST(zone->iss == NULL);

  if (zone->masterfile != NULL) {
    isc_mem_free(zone->mctx, zone->masterfile);
  }
  if (zone->initfile != NULL) {
    isc_mem_free(zone->mctx, zone->initfile);
  }
  if (zone->keydirectory != NULL) {
    isc_mem_free(zone->mctx, zone->keydirectory);
  }

  if (zone->kasp != NULL) {
    dns_kasp_detach(&zone->kasp);
  }
  if (zone->defaultkasp != NULL) {
    dns_kasp_detach(&zone->defaultkasp);
  }
  if (!ISC_LIST_EMPTY(zone->keyring)) {
    clear_keylist(&zone->keyring, zone->mctx);
  }
  if (!ISC_LIST_EMPTY(zone->checkds_ok)) {
    clear_keylist(&zone->checkds_ok, zone->mctx);
  }
  if (zone->skr != NULL) {
    zone->skrbundle = NULL;
    dns_skr_detach(&zone->skr);
  }

  zone->journalsize = -1;
  if (zone->journal != NULL) {
    isc_mem_free(zone->mctx, zone->journal);
  }
  if (zone->stats != NULL) {
    isc_stats_detach(&zone->stats);
  }
  if (zone->requeststats != NULL) {
    isc_stats_detach(&zone->requeststats);
  }
  if (zone->rcvquerystats != NULL) {
    isc_statsmulti_detach(&zone->rcvquerystats);
  }
  if (zone->dnssecsignstats != NULL) {
    dns_stats_detach(&zone->dnssecsignstats);
  }
  if (zone->db != NULL) {
    zone_detachdb(zone);
  }
  if (zone->rpzs != NULL) {
    REQUIRE(zone->rpz_num < zone->rpzs->p.num_zones);
    dns_rpz_zones_detach(&zone->rpzs);
    zone->rpz_num = DNS_RPZ_INVALID_NUM;
  }
  if (zone->catzs != NULL) {
    dns_catz_zones_detach(&zone->catzs);
  }
  dns__zone_freedbargs(zone);

  dns_zone_setparentals(zone, NULL, NULL, NULL, NULL, 0);
  dns_zone_setprimaries(zone, NULL, NULL, NULL, NULL, 0);
  dns_zone_setalsonotify(zone, NULL, NULL, NULL, NULL, 0);
  dns_zone_setcdsendpoints(zone, NULL, NULL, NULL, NULL, 0);

  if (zone->update_acl != NULL) {
    dns_acl_detach(&zone->update_acl);
  }
  if (zone->forward_acl != NULL) {
    dns_acl_detach(&zone->forward_acl);
  }
  if (zone->notifysoa.notify_acl != NULL) {
    dns_acl_detach(&zone->notifysoa.notify_acl);
  }
  if (zone->notifycds.notify_acl != NULL) {
    dns_acl_detach(&zone->notifycds.notify_acl);
  }
  if (zone->query_acl != NULL) {
    dns_acl_detach(&zone->query_acl);
  }
  if (zone->queryon_acl != NULL) {
    dns_acl_detach(&zone->queryon_acl);
  }
  if (zone->xfr_acl != NULL) {
    dns_acl_detach(&zone->xfr_acl);
  }
  if (dns_name_dynamic(&zone->origin)) {
    dns_name_free(&zone->origin, zone->mctx);
  }

  dns_zone_setrad(zone, NULL);
  dns__viewname_free(&zone->viewname, zone->mctx);

  if (zone->ssutable != NULL) {
    dns_ssutable_detach(&zone->ssutable);
  }
  if (zone->gluecachestats != NULL) {
    isc_stats_detach(&zone->gluecachestats);
  }

  /* last stuff */
  if (zone->loop != NULL) {
    isc_loop_detach(&zone->loop);
  }
  ZONEDB_DESTROYLOCK(&zone->dblock);
  isc_mutex_destroy(&zone->lock);
  zone->magic = 0;
  isc_mem_t *mctx = zone->mctx;
  isc_mem_putx(mctx, zone, sizeof(*zone),
         ISC_MEM_ALIGN(ISC_OS_CACHELINE_SIZE));
  isc_mem_detach(&mctx);
}

/*
 * Returns true iff this the signed side of an inline-signing zone.
 * Caller should hold zone lock.
 */
bool
dns__zone_inline_secure(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  if (zone->raw != NULL) {
    return true;
  }
  return false;
}

/*
 * Returns true iff this the unsigned side of an inline-signing zone
 * Caller should hold zone lock.
 */
bool
dns__zone_inline_raw(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  if (zone->secure != NULL) {
    return true;
  }
  return false;
}

isc_result_t
dns_zone_getserial(dns_zone_t *zone, uint32_t *serialp) {
  isc_result_t result;
  unsigned int soacount;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(serialp != NULL);

  LOCK_ZONE(zone);
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    result = zone_get_from_db(zone, zone->db, NULL, &soacount, NULL,
            serialp, NULL, NULL, NULL, NULL,
            NULL);
    if (result == ISC_R_SUCCESS && soacount == 0) {
      result = ISC_R_FAILURE;
    }
  } else {
    result = DNS_R_NOTLOADED;
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  UNLOCK_ZONE(zone);

  return result;
}

isc_result_t
dns_zone_getzoneversion(dns_zone_t *zone, isc_buffer_t *b) {
  isc_result_t result = DNS_R_NOTLOADED;
  unsigned int soacount;
  uint32_t serial;
  dns_zone_t *mayberaw = zone;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(b != NULL);

  LOCK_ZONE(zone);
  if (zone->raw != NULL) {
    LOCK_ZONE(zone->raw);
    mayberaw = zone->raw;
  }
  ZONEDB_LOCK(&mayberaw->dblock, isc_rwlocktype_read);
  if (DNS_ZONE_OPTION(mayberaw, DNS_ZONEOPT_ZONEVERSION) &&
      mayberaw->db != NULL)
  {
    result = dns_db_getzoneversion(mayberaw->db, b);
    if (result == ISC_R_NOTIMPLEMENTED) {
      result = zone_get_from_db(mayberaw, mayberaw->db, NULL,
              &soacount, NULL, &serial,
              NULL, NULL, NULL, NULL, NULL);
      if (result == ISC_R_SUCCESS && soacount == 0) {
        result = ISC_R_FAILURE;
      }
      if (result == ISC_R_SUCCESS) {
        if (isc_buffer_availablelength(b) >= 6) {
          isc_buffer_putuint8(
            b, dns_name_countlabels(
                 &mayberaw->origin) -
                 1);
          isc_buffer_putuint8(b, 0);
          isc_buffer_putuint32(b, serial);
        } else {
          result = ISC_R_NOSPACE;
        }
      }
    }
  }
  ZONEDB_UNLOCK(&mayberaw->dblock, isc_rwlocktype_read);
  if (zone->raw != NULL) {
    UNLOCK_ZONE(zone->raw);
  }
  UNLOCK_ZONE(zone);

  return result;
}

void
dns__zone_freedbargs(dns_zone_t *zone) {
  unsigned int i;

  /* Free the old database argument list. */
  if (zone->db_argv != NULL) {
    for (i = 0; i < zone->db_argc; i++) {
      isc_mem_free(zone->mctx, zone->db_argv[i]);
    }
    isc_mem_cput(zone->mctx, zone->db_argv, zone->db_argc,
           sizeof(*zone->db_argv));
  }
  zone->db_argc = 0;
  zone->db_argv = NULL;
}

void
dns__zone_setview_helper(dns_zone_t *zone, dns_view_t *view) {
  dns__viewname_set(&zone->viewname, zone->mctx, view->name);
  if (zone->prev_view == NULL && zone->view != NULL) {
    dns_view_weakattach(zone->view, &zone->prev_view);
  }

  INSIST(zone != zone->raw);
  if (zone->view != NULL) {
    dns_view_sfd_del(zone->view, &zone->origin);
    dns_view_weakdetach(&zone->view);
  }
  dns_view_weakattach(view, &zone->view);
  dns_view_sfd_add(view, &zone->origin);

  if (dns__zone_inline_secure(zone)) {
    dns_zone_setview(zone->raw, view);
  }
}

void
dns_zone_setviewcommit(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  if (zone->prev_view != NULL) {
    dns_view_weakdetach(&zone->prev_view);
  }
  if (dns__zone_inline_secure(zone)) {
    dns_zone_setviewcommit(zone->raw);
  }
  UNLOCK_ZONE(zone);
}

void
dns_zone_setviewrevert(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  if (zone->prev_view != NULL) {
    dns__zone_setview_helper(zone, zone->prev_view);
    dns_view_weakdetach(&zone->prev_view);
  }
  if (zone->catzs != NULL) {
    zone_catz_enable(zone, zone->catzs);
  }
  if (dns__zone_inline_secure(zone)) {
    dns_zone_setviewrevert(zone->raw);
  }
  UNLOCK_ZONE(zone);
}

/*
 * Return true iff the zone is "dynamic", in the sense that the zone's
 * master file (if any) is written by the server, rather than being
 * updated manually and read by the server.
 *
 * This is true for secondary zones, mirror zones, stub zones, key zones,
 * and zones that allow dynamic updates either by having an update
 * policy ("ssutable") or an "allow-update" ACL with a value other than
 * exactly "{ none; }".
 */
bool
dns_zone_isdynamic(dns_zone_t *zone, bool ignore_freeze) {
  REQUIRE(DNS_ZONE_VALID(zone));

  if (zone->type == dns_zone_secondary || zone->type == dns_zone_mirror ||
      zone->type == dns_zone_stub || zone->type == dns_zone_key ||
      (zone->type == dns_zone_redirect &&
       dns_remote_addresses(&zone->primaries) != NULL))
  {
    return true;
  }

  /* Inline zones are always dynamic. */
  if (zone->type == dns_zone_primary && zone->raw != NULL) {
    return true;
  }

  /* If !ignore_freeze, we need check whether updates are disabled.  */
  if (zone->type == dns_zone_primary &&
      (!zone->update_disabled || ignore_freeze) &&
      ((zone->ssutable != NULL) ||
       (zone->update_acl != NULL && !dns_acl_isnone(zone->update_acl))))
  {
    return true;
  }

  return false;
}

/*
 * Set the response policy index and information for a zone.
 */
isc_result_t
dns_zone_rpz_enable(dns_zone_t *zone, dns_rpz_zones_t *rpzs,
        dns_rpz_num_t rpz_num) {
  /*
   * This must happen only once or be redundant.
   */
  LOCK_ZONE(zone);
  if (zone->rpzs != NULL) {
    REQUIRE(zone->rpzs == rpzs && zone->rpz_num == rpz_num);
  } else {
    REQUIRE(zone->rpz_num == DNS_RPZ_INVALID_NUM);
    dns_rpz_zones_attach(rpzs, &zone->rpzs);
    zone->rpz_num = rpz_num;
  }
  rpzs->defined |= DNS_RPZ_ZBIT(rpz_num);
  UNLOCK_ZONE(zone);

  return ISC_R_SUCCESS;
}

dns_rpz_num_t
dns_zone_get_rpz_num(dns_zone_t *zone) {
  return zone->rpz_num;
}

/*
 * If a zone is a response policy zone, mark its new database.
 */
void
dns_zone_rpz_enable_db(dns_zone_t *zone, dns_db_t *db) {
  if (zone->rpz_num == DNS_RPZ_INVALID_NUM) {
    return;
  }
  REQUIRE(zone->rpzs != NULL);
  dns_rpz_dbupdate_register(db, zone->rpzs->zones[zone->rpz_num]);
}

static void
dns_zone_rpz_disable_db(dns_zone_t *zone, dns_db_t *db) {
  if (zone->rpz_num == DNS_RPZ_INVALID_NUM) {
    return;
  }
  REQUIRE(zone->rpzs != NULL);
  dns_rpz_dbupdate_unregister(db, zone->rpzs->zones[zone->rpz_num]);
}

/*
 * If a zone is a catalog zone, attach it to update notification in database.
 */
void
dns_zone_catz_enable_db(dns_zone_t *zone, dns_db_t *db) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(db != NULL);

  if (zone->catzs != NULL) {
    dns_catz_dbupdate_register(db, zone->catzs);
  }
}

static void
dns_zone_catz_disable_db(dns_zone_t *zone, dns_db_t *db) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(db != NULL);

  if (zone->catzs != NULL) {
    dns_catz_dbupdate_unregister(db, zone->catzs);
  }
}

static void
zone_catz_enable(dns_zone_t *zone, dns_catz_zones_t *catzs) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(catzs != NULL);

  INSIST(zone->catzs == NULL || zone->catzs == catzs);
  dns_catz_catzs_set_view(catzs, zone->view);
  if (zone->catzs == NULL) {
    dns_catz_zones_attach(catzs, &zone->catzs);
  }
}

void
dns_zone_catz_enable(dns_zone_t *zone, dns_catz_zones_t *catzs) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  zone_catz_enable(zone, catzs);
  UNLOCK_ZONE(zone);
}

static void
zone_catz_disable(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  if (zone->catzs != NULL) {
    if (zone->db != NULL) {
      dns_zone_catz_disable_db(zone, zone->db);
    }
    dns_catz_zones_detach(&zone->catzs);
  }
}

void
dns_zone_catz_disable(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  zone_catz_disable(zone);
  UNLOCK_ZONE(zone);
}

bool
dns_zone_catz_is_enabled(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return zone->catzs != NULL;
}

/*
 * Set catalog zone ownership of the zone
 */
void
dns_zone_set_parentcatz(dns_zone_t *zone, dns_catz_zone_t *catz) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(catz != NULL);
  LOCK_ZONE(zone);
  INSIST(zone->parentcatz == NULL || zone->parentcatz == catz);
  zone->parentcatz = catz;
  UNLOCK_ZONE(zone);
}

dns_catz_zone_t *
dns_zone_get_parentcatz(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  dns_catz_zone_t *parentcatz = NULL;

  LOCK_ZONE(zone);
  parentcatz = zone->parentcatz;
  UNLOCK_ZONE(zone);

  return parentcatz;
}

static bool
zone_touched(dns_zone_t *zone) {
  isc_result_t result;
  isc_time_t modtime;

  REQUIRE(DNS_ZONE_VALID(zone));

  result = isc_file_getmodtime(zone->masterfile, &modtime);
  if (result != ISC_R_SUCCESS ||
      isc_time_compare(&modtime, &zone->loadtime) > 0)
  {
    return true;
  }

  ISC_LIST_FOREACH(zone->includes, include, link) {
    result = isc_file_getmodtime(include->name, &modtime);
    if (result != ISC_R_SUCCESS ||
        isc_time_compare(&modtime, &include->filetime) > 0)
    {
      return true;
    }
  }

  return false;
}

static isc_result_t
copy_initfile(dns_zone_t *zone) {
  isc_result_t result;
  FILE *input = NULL, *output = NULL;
  off_t len;

  CHECK(isc_stdio_open(zone->initfile, "r", &input));
  CHECK(isc_stdio_open(zone->masterfile, "w", &output));

  CHECK(isc_file_getsizefd(fileno(input), &len));

  do {
    char buf[BUFSIZ];
    size_t rval;

    result = isc_stdio_read(buf, 1, sizeof(buf), input, &rval);
    if (result != ISC_R_EOF) {
      CHECK(result);
    }
    CHECK(isc_stdio_write(buf, rval, 1, output, NULL));
    len -= rval;
  } while (len > 0);

cleanup:
  if (input != NULL) {
    isc_stdio_close(input);
  }
  if (output != NULL) {
    if (result != ISC_R_SUCCESS) {
      isc_file_remove(zone->masterfile);
    }
    isc_stdio_close(output);
  }
  return result;
}

/*
 * Note: when dealing with inline-signed zones, external callers will always
 * call zone_load() for the secure zone; zone_load() calls itself recursively
 * in order to load the raw zone.
 */
static isc_result_t
zone_load(dns_zone_t *zone, unsigned int flags, bool locked) {
  isc_result_t result;
  isc_time_t now;
  isc_time_t loadtime;
  dns_db_t *db = NULL;
  bool rbt, hasraw, is_dynamic;

  REQUIRE(DNS_ZONE_VALID(zone));

  if (!locked) {
    LOCK_ZONE(zone);
  }

  INSIST(zone != zone->raw);
  hasraw = dns__zone_inline_secure(zone);
  if (hasraw) {
    /*
     * We are trying to load an inline-signed zone.  First call
     * self recursively to try loading the raw version of the zone.
     * Assuming the raw zone file is readable, there are two
     * possibilities:
     *
     *  a) the raw zone was not yet loaded and thus it will be
     *     loaded now, synchronously; if this succeeds, a
     *     subsequent attempt to load the signed zone file will
     *     take place and thus zone_postload() will be called
     *     twice: first for the raw zone and then for the secure
     *     zone; the latter call will be followed by scheduling
     *     secure maintenance to sync against the raw version,
     *
     *  b) the raw zone was already loaded and we are trying to
     *     reload it, which will happen asynchronously; this means
     *     zone_postload() will only be called for the raw zone
     *     because "result" returned by the zone_load() call below
     *     will not be ISC_R_SUCCESS but rather DNS_R_CONTINUE;
     *     zone_postload() called for the raw zone will schedule
     *     secure maintenance to sync against the raw version.
     */
    result = zone_load(zone->raw, flags, false);
    if (result != ISC_R_SUCCESS) {
      if (!locked) {
        UNLOCK_ZONE(zone);
      }
      return result;
    }
  }

  now = isc_time_now();

  INSIST(zone->type != dns_zone_none);

  /* load was already in progress */
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADING)) {
    if ((flags & DNS_ZONELOADFLAG_THAW) != 0) {
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_THAW);
    }
    CLEANUP(ISC_R_LOADING);
  }

  INSIST(zone->db_argc >= 1);

  rbt = strcmp(zone->db_argv[0], ZONEDB_DEFAULT) == 0;

  if (zone->db != NULL && zone->masterfile == NULL && rbt) {
    /*
     * The zone has no master file configured.
     */
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  is_dynamic = dns_zone_isdynamic(zone, false);
  if (zone->db != NULL && is_dynamic) {
    /*
     * This is a secondary, stub, or dynamically updated zone
     * being reloaded.  Do nothing - the database we already
     * have is guaranteed to be up-to-date.
     */
    if (zone->type == dns_zone_primary && !hasraw) {
      result = DNS_R_DYNAMIC;
    } else {
      result = ISC_R_SUCCESS;
    }
    goto cleanup;
  }

  /*
   * Store the current time before the zone is loaded, so that if the
   * file changes between the time of the load and the time that
   * zone->loadtime is set, then the file will still be reloaded
   * the next time dns_zone_load is called.
   */
  loadtime = isc_time_now();

  /*
   * Don't do the load if the file that stores the zone is older
   * than the last time the zone was loaded.  If the zone has not
   * been loaded yet, zone->loadtime will be the epoch.
   */
  if (zone->masterfile != NULL) {
    isc_time_t filetime;

    /*
     * The file is already loaded.  If we are just doing a
     * "rndc reconfig", we are done.
     */
    if (!isc_time_isepoch(&zone->loadtime) &&
        (flags & DNS_ZONELOADFLAG_NOSTAT) != 0)
    {
      result = ISC_R_SUCCESS;
      goto cleanup;
    }

    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
        !zone_touched(zone))
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_DEBUG(1),
              "skipping load: master file "
              "older than last load");
      CLEANUP(DNS_R_UPTODATE);
    }

    /*
     * If the file modification time is in the past
     * set loadtime to that value.
     */
    result = isc_file_getmodtime(zone->masterfile, &filetime);
    if (result == ISC_R_SUCCESS &&
        isc_time_compare(&loadtime, &filetime) > 0)
    {
      loadtime = filetime;
    }
  }

  /*
   * Built in zones (with the exception of empty zones) don't need
   * to be reloaded.
   */
  if (zone->type == dns_zone_primary &&
      strcmp(zone->db_argv[0], "_builtin") == 0 &&
      (zone->db_argc < 2 || strcmp(zone->db_argv[1], "empty") != 0) &&
      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
  {
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  /*
   * Zones associated with a DLZ don't need to be loaded either,
   * but we need to associate the database with the zone object.
   */
  if (strcmp(zone->db_argv[0], "dlz") == 0) {
    dns_dlzdb_t *dlzdb = NULL;
    dns_dlzfindzone_t findzone;

    ISC_LIST_FOREACH(zone->view->dlz_unsearched, d, link) {
      INSIST(DNS_DLZ_VALID(d));
      if (strcmp(zone->db_argv[1], d->dlzname) == 0) {
        dlzdb = d;
        break;
      }
    }

    if (dlzdb == NULL) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_ERROR,
              "DLZ %s does not exist or is set "
              "to 'search yes;'",
              zone->db_argv[1]);
      CLEANUP(ISC_R_NOTFOUND);
    }

    ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
    /* ask SDLZ driver if the zone is supported */
    findzone = dlzdb->implementation->methods->findzone;
    result = (*findzone)(dlzdb->implementation->driverarg,
             dlzdb->dbdata, dlzdb->mctx,
             zone->view->rdclass, &zone->origin, NULL,
             NULL, &db);
    if (result != ISC_R_NOTFOUND) {
      if (zone->db != NULL) {
        zone_detachdb(zone);
      }
      zone_attachdb(zone, db);
      dns_db_detach(&db);
      result = ISC_R_SUCCESS;
    }
    ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);

    if (result == ISC_R_SUCCESS) {
      if (dlzdb->configure_callback == NULL) {
        goto cleanup;
      }

      result = (*dlzdb->configure_callback)(zone->view, dlzdb,
                    zone);
      if (result != ISC_R_SUCCESS) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_ERROR,
                "DLZ configuration callback: %s",
                isc_result_totext(result));
      }
    }
    goto cleanup;
  }

  if ((zone->type == dns_zone_secondary ||
       zone->type == dns_zone_mirror || zone->type == dns_zone_stub ||
       (zone->type == dns_zone_redirect &&
        dns_remote_addresses(&zone->primaries) != NULL)) &&
      rbt)
  {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FIRSTREFRESH);

    if (zone->stream == NULL &&
        (zone->masterfile == NULL ||
         !isc_file_exists(zone->masterfile)))
    {
      if (zone->masterfile != NULL) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_DEBUG(1),
                "no master file");
      }
      zone->refreshtime = now;
      if (zone->loop != NULL) {
        dns__zone_settimer(zone, now);
      }
      result = ISC_R_SUCCESS;
      goto cleanup;
    }
  }

  if (zone->type == dns_zone_primary && zone->masterfile != NULL &&
      !isc_file_exists(zone->masterfile) && zone->initfile != NULL)
  {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_INFO,
            "zone file %s not found; copying initial "
            "file %s",
            zone->masterfile, zone->initfile);
    result = copy_initfile(zone);
    if (result != ISC_R_SUCCESS) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_ERROR, "copy from %s failed: %s",
              zone->initfile,
              isc_result_totext(result));
    }
  }

  dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_DEBUG(1),
          "starting load");

  result = dns_zone_makedb(zone, &db);
  if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_ERROR,
            "loading zone: creating database: %s",
            isc_result_totext(result));
    goto cleanup;
  }

  if (!dns_db_ispersistent(db)) {
    if (zone->masterfile != NULL || zone->stream != NULL) {
      result = zone_startload(db, zone, loadtime);
    } else {
      result = DNS_R_NOMASTERFILE;
      if (zone->type == dns_zone_primary ||
          (zone->type == dns_zone_redirect &&
           dns_remote_addresses(&zone->primaries) == NULL))
      {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_ERROR,
                "loading zone: "
                "no master file configured");
        goto cleanup;
      }
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_INFO,
              "loading zone: "
              "no master file configured: continuing");
    }
  }

  if (result == DNS_R_CONTINUE) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADING);
    if ((flags & DNS_ZONELOADFLAG_THAW) != 0) {
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_THAW);
    }
    goto cleanup;
  }

  result = zone_postload(zone, db, loadtime, result);
  if (hasraw && result == ISC_R_SUCCESS) {
    zone_schedule_inline_sync(zone, inline_sync_incremental);
  }

cleanup:
  if (!locked) {
    UNLOCK_ZONE(zone);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }
  return result;
}

isc_result_t
dns_zone_load(dns_zone_t *zone, bool newonly) {
  return zone_load(zone, newonly ? DNS_ZONELOADFLAG_NOSTAT : 0, false);
}

static void
zone_asyncload(void *arg) {
  dns_asyncload_t *asl = arg;
  dns_zone_t *zone = asl->zone;
  isc_result_t result;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  result = zone_load(zone, asl->flags, true);
  if (result != DNS_R_CONTINUE && result != ISC_R_LOADING) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_LOADPENDING);
  }
  UNLOCK_ZONE(zone);

  /* Inform the zone table we've finished loading */
  if (asl->loaded != NULL) {
    asl->loaded(asl->loaded_arg);
  }

  isc_mem_put(zone->mctx, asl, sizeof(*asl));
  dns_zone_idetach(&zone);
}

isc_result_t
dns_zone_asyncload(dns_zone_t *zone, bool newonly, dns_zt_callback_t *done,
       void *arg) {
  dns_asyncload_t *asl = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));

  if (zone->loop == NULL) {
    return ISC_R_FAILURE;
  }

  /* If we already have a load pending, stop now */
  LOCK_ZONE(zone);
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADPENDING)) {
    UNLOCK_ZONE(zone);
    return ISC_R_ALREADYRUNNING;
  }

  asl = isc_mem_get(zone->mctx, sizeof(*asl));

  asl->zone = NULL;
  asl->flags = newonly ? DNS_ZONELOADFLAG_NOSTAT : 0;
  asl->loaded = done;
  asl->loaded_arg = arg;

  zone_iattach(zone, &asl->zone);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADPENDING);
  isc_async_run(zone->loop, zone_asyncload, asl);
  UNLOCK_ZONE(zone);

  return ISC_R_SUCCESS;
}

bool
dns__zone_loadpending(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADPENDING);
}

isc_result_t
dns_zone_loadandthaw(dns_zone_t *zone) {
  isc_result_t result;
  bool inline_raw;

  LOCK_ZONE(zone);
  inline_raw = dns__zone_inline_raw(zone);
  UNLOCK_ZONE(zone);

  if (inline_raw) {
    result = zone_load(zone->secure, DNS_ZONELOADFLAG_THAW, false);
  } else {
    /*
     * When thawing a zone, we don't know what changes
     * have been made. If we do DNSSEC maintenance on this
     * zone, schedule a full sign for this zone.
     */
    if (zone->type == dns_zone_primary && zone->kasp != NULL) {
      DNS_ZONE_SETOPTION(zone, DNS_ZONEOPT_FULLSIGN);
    }
    result = zone_load(zone, DNS_ZONELOADFLAG_THAW, false);
  }

  switch (result) {
  case DNS_R_CONTINUE:
  case ISC_R_LOADING:
    /* Deferred thaw. */
    break;
  case DNS_R_UPTODATE:
  case ISC_R_SUCCESS:
  case DNS_R_SEENINCLUDE:
    zone->update_disabled = false;
    break;
  case DNS_R_NOMASTERFILE:
    zone->update_disabled = false;
    break;
  default:
    /* Error, remain in disabled state. */
    break;
  }
  return result;
}

static unsigned int
get_primary_options(dns_zone_t *zone) {
  unsigned int options;

  options = DNS_MASTER_ZONE | DNS_MASTER_RESIGN;
  if (zone->type == dns_zone_secondary || zone->type == dns_zone_mirror ||
      (zone->type == dns_zone_redirect &&
       dns_remote_addresses(&zone->primaries) == NULL))
  {
    options |= DNS_MASTER_SECONDARY;
  }
  if (zone->type == dns_zone_key) {
    options |= DNS_MASTER_KEY;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNS)) {
    options |= DNS_MASTER_CHECKNS;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FATALNS)) {
    options |= DNS_MASTER_FATALNS;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMES)) {
    options |= DNS_MASTER_CHECKNAMES;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMESFAIL)) {
    options |= DNS_MASTER_CHECKNAMESFAIL;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKMX)) {
    options |= DNS_MASTER_CHECKMX;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKMXFAIL)) {
    options |= DNS_MASTER_CHECKMXFAIL;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKWILDCARD)) {
    options |= DNS_MASTER_CHECKWILDCARD;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKTTL)) {
    options |= DNS_MASTER_CHECKTTL;
  }
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKSVCB)) {
    options |= DNS_MASTER_CHECKSVCB;
  }

  return options;
}

static void
zone_registerinclude(const char *filename, void *arg) {
  isc_result_t result;
  dns_zone_t *zone = (dns_zone_t *)arg;

  REQUIRE(DNS_ZONE_VALID(zone));

  if (filename == NULL) {
    return;
  }

  /*
   * Suppress duplicates.
   */
  ISC_LIST_FOREACH(zone->newincludes, inc, link) {
    if (strcmp(filename, inc->name) == 0) {
      return;
    }
  }

  dns_include_t *inc = isc_mem_get(zone->mctx, sizeof(dns_include_t));
  inc->name = isc_mem_strdup(zone->mctx, filename);
  ISC_LINK_INIT(inc, link);

  result = isc_file_getmodtime(filename, &inc->filetime);
  if (result != ISC_R_SUCCESS) {
    isc_time_settoepoch(&inc->filetime);
  }

  ISC_LIST_APPEND(zone->newincludes, inc, link);
}

static void
get_raw_serial(dns_zone_t *raw, dns_masterrawheader_t *rawdata) {
  isc_result_t result;
  unsigned int soacount;

  LOCK(&raw->lock);
  if (raw->db != NULL) {
    result = zone_get_from_db(raw, raw->db, NULL, &soacount, NULL,
            &rawdata->sourceserial, NULL, NULL,
            NULL, NULL, NULL);
    if (result == ISC_R_SUCCESS && soacount > 0U) {
      rawdata->flags |= DNS_MASTERRAW_SOURCESERIALSET;
    }
  }
  UNLOCK(&raw->lock);
}

/*
 * Save the raw serial number for inline-signing zones.
 * (XXX: Other information from the header will be used
 * for other purposes in the future, but for now this is
 * all we're interested in.)
 */
static void
zone_setrawdata(dns_zone_t *zone, dns_masterrawheader_t *header) {
  if ((header->flags & DNS_MASTERRAW_SOURCESERIALSET) == 0) {
    return;
  }

  zone->sourceserial = header->sourceserial;
  zone->sourceserialset = true;
}

void
dns_zone_setrawdata(dns_zone_t *zone, dns_masterrawheader_t *header) {
  if (zone == NULL) {
    return;
  }

  LOCK_ZONE(zone);
  zone_setrawdata(zone, header);
  UNLOCK_ZONE(zone);
}

static isc_result_t
zone_startload(dns_db_t *db, dns_zone_t *zone, isc_time_t loadtime) {
  isc_result_t result;
  isc_result_t tresult;
  unsigned int options;
  dns_load_t *load = isc_mem_get(zone->mctx, sizeof(*load));

  ENTER;

  *load = (dns_load_t){
    .loadtime = loadtime,
  };

  dns_zone_rpz_enable_db(zone, db);
  dns_zone_catz_enable_db(zone, db);

  options = get_primary_options(zone);
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_MANYERRORS)) {
    options |= DNS_MASTER_MANYERRORS;
  }

  zone_iattach(zone, &load->zone);
  dns_db_attach(db, &load->db);

  dns_rdatacallbacks_init(&load->callbacks);
  load->callbacks.rawdata = zone_setrawdata;
  zone_iattach(zone, &load->callbacks.zone);

  CHECK(dns_db_beginload(db, &load->callbacks));

  if (zone->loop != NULL && zone->db != NULL) {
    CHECK(dns_master_loadfileasync(
      zone->masterfile, dns_db_origin(db), dns_db_origin(db),
      zone->rdclass, options, 0, &load->callbacks, zone->loop,
      zone_loaddone, load, &zone->loadctx,
      zone_registerinclude, zone, zone->mctx,
      zone->masterformat, zone->maxttl));

    return DNS_R_CONTINUE;
  } else if (zone->stream != NULL) {
    FILE *stream = UNCONST(zone->stream);
    result = dns_master_loadstream(
      stream, &zone->origin, &zone->origin, zone->rdclass,
      options, &load->callbacks, zone->mctx);
  } else {
    result = dns_master_loadfile(
      zone->masterfile, &zone->origin, &zone->origin,
      zone->rdclass, options, 0, &load->callbacks,
      zone_registerinclude, zone, zone->mctx,
      zone->masterformat, zone->maxttl);
  }

cleanup:
  if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) {
    dns_zone_rpz_disable_db(zone, load->db);
    dns_zone_catz_disable_db(zone, load->db);
  }

  tresult = dns_db_endload(db, &load->callbacks);
  if (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE) {
    result = tresult;
  }

  zone_idetach(&load->callbacks.zone);
  dns_db_detach(&load->db);
  zone_idetach(&load->zone);

  isc_mem_put(zone->mctx, load, sizeof(*load));
  return result;
}

static bool
zone_check_mx(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
        dns_name_t *owner) {
  isc_result_t result;
  char ownerbuf[DNS_NAME_FORMATSIZE];
  char namebuf[DNS_NAME_FORMATSIZE];
  char altbuf[DNS_NAME_FORMATSIZE];
  dns_fixedname_t fixed;
  dns_name_t *foundname;
  int level;

  /*
   * "." means the services does not exist.
   */
  if (dns_name_isroot(name)) {
    return true;
  }

  /*
   * Outside of zone.
   */
  if (!dns_name_issubdomain(name, &zone->origin)) {
    if (zone->checkmx) {
      return (zone->ops->checkmx)(zone, name, owner);
    }
    return true;
  }

  if (zone->type == dns_zone_primary) {
    level = ISC_LOG_ERROR;
  } else {
    level = ISC_LOG_WARNING;
  }

  foundname = dns_fixedname_initname(&fixed);

  result = dns_db_find(db, name, NULL, dns_rdatatype_a, 0, 0, foundname,
           NULL, NULL);
  if (result == ISC_R_SUCCESS) {
    return true;
  }

  if (result == DNS_R_NXRRSET) {
    result = dns_db_find(db, name, NULL, dns_rdatatype_aaaa, 0, 0,
             foundname, NULL, NULL);
    if (result == ISC_R_SUCCESS) {
      return true;
    }
  }

  dns_name_format(owner, ownerbuf, sizeof ownerbuf);
  dns_name_format(name, namebuf, sizeof namebuf);
  if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
      result == DNS_R_EMPTYNAME)
  {
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKMXFAIL)) {
      level = ISC_LOG_WARNING;
    }
    dns_zone_log(zone, level,
           "%s/MX '%s' has no address records (A or AAAA)",
           ownerbuf, namebuf);
    return (level == ISC_LOG_WARNING) ? true : false;
  }

  if (result == DNS_R_CNAME) {
    if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNMXCNAME) ||
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME))
    {
      level = ISC_LOG_WARNING;
    }
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME)) {
      dns_zone_log(zone, level,
             "%s/MX '%s' is a CNAME (illegal)",
             ownerbuf, namebuf);
    }
    return (level == ISC_LOG_WARNING) ? true : false;
  }

  if (result == DNS_R_DNAME) {
    if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNMXCNAME) ||
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME))
    {
      level = ISC_LOG_WARNING;
    }
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME)) {
      dns_name_format(foundname, altbuf, sizeof altbuf);
      dns_zone_log(zone, level,
             "%s/MX '%s' is below a DNAME"
             " '%s' (illegal)",
             ownerbuf, namebuf, altbuf);
    }
    return (level == ISC_LOG_WARNING) ? true : false;
  }

  if (zone->checkmx && result == DNS_R_DELEGATION) {
    return (zone->ops->checkmx)(zone, name, owner);
  }

  return true;
}

static bool
zone_check_srv(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
         dns_name_t *owner) {
  isc_result_t result;
  char ownerbuf[DNS_NAME_FORMATSIZE];
  char namebuf[DNS_NAME_FORMATSIZE];
  char altbuf[DNS_NAME_FORMATSIZE];
  dns_fixedname_t fixed;
  dns_name_t *foundname;
  int level;

  /*
   * "." means the services does not exist.
   */
  if (dns_name_isroot(name)) {
    return true;
  }

  /*
   * Outside of zone.
   */
  if (!dns_name_issubdomain(name, &zone->origin)) {
    if (zone->checksrv) {
      return (zone->ops->checksrv)(zone, name, owner);
    }
    return true;
  }

  if (zone->type == dns_zone_primary) {
    level = ISC_LOG_ERROR;
  } else {
    level = ISC_LOG_WARNING;
  }

  foundname = dns_fixedname_initname(&fixed);

  result = dns_db_find(db, name, NULL, dns_rdatatype_a, 0, 0, foundname,
           NULL, NULL);
  if (result == ISC_R_SUCCESS) {
    return true;
  }

  if (result == DNS_R_NXRRSET) {
    result = dns_db_find(db, name, NULL, dns_rdatatype_aaaa, 0, 0,
             foundname, NULL, NULL);
    if (result == ISC_R_SUCCESS) {
      return true;
    }
  }

  dns_name_format(owner, ownerbuf, sizeof ownerbuf);
  dns_name_format(name, namebuf, sizeof namebuf);
  if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
      result == DNS_R_EMPTYNAME)
  {
    dns_zone_log(zone, level,
           "%s/SRV '%s' has no address records (A or AAAA)",
           ownerbuf, namebuf);
    /* XXX950 make fatal for 9.5.0. */
    return true;
  }

  if (result == DNS_R_CNAME) {
    if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNSRVCNAME) ||
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME))
    {
      level = ISC_LOG_WARNING;
    }
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME)) {
      dns_zone_log(zone, level,
             "%s/SRV '%s' is a CNAME (illegal)",
             ownerbuf, namebuf);
    }
    return (level == ISC_LOG_WARNING) ? true : false;
  }

  if (result == DNS_R_DNAME) {
    if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNSRVCNAME) ||
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME))
    {
      level = ISC_LOG_WARNING;
    }
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME)) {
      dns_name_format(foundname, altbuf, sizeof altbuf);
      dns_zone_log(zone, level,
             "%s/SRV '%s' is below a "
             "DNAME '%s' (illegal)",
             ownerbuf, namebuf, altbuf);
    }
    return (level == ISC_LOG_WARNING) ? true : false;
  }

  if (zone->checksrv && result == DNS_R_DELEGATION) {
    return (zone->ops->checksrv)(zone, name, owner);
  }

  return true;
}

static bool
zone_check_glue(dns_zone_t *zone, dns_db_t *db, bool *has_a, bool *has_aaaa,
    dns_name_t *name, dns_name_t *owner) {
  bool answer = true;
  isc_result_t result, tresult;
  char ownerbuf[DNS_NAME_FORMATSIZE];
  char namebuf[DNS_NAME_FORMATSIZE];
  char altbuf[DNS_NAME_FORMATSIZE];
  dns_fixedname_t fixed;
  dns_name_t *foundname;
  dns_rdataset_t a;
  dns_rdataset_t aaaa;
  int level;

  /*
   * Outside of zone.
   */
  if (!dns_name_issubdomain(name, &zone->origin)) {
    if (zone->checkns) {
      return (zone->ops->checkns)(zone, name, owner, NULL,
                NULL);
    }
    return true;
  }

  if (zone->type == dns_zone_primary) {
    level = ISC_LOG_ERROR;
  } else {
    level = ISC_LOG_WARNING;
  }

  foundname = dns_fixedname_initname(&fixed);
  dns_rdataset_init(&a);
  dns_rdataset_init(&aaaa);

  /*
   * Perform a regular lookup to catch DNAME records then look
   * for glue.
   */
  result = dns_db_find(db, name, NULL, dns_rdatatype_a, 0, 0, foundname,
           &a, NULL);
  switch (result) {
  case ISC_R_SUCCESS:
  case DNS_R_DNAME:
  case DNS_R_CNAME:
    break;
  default:
    dns_rdataset_cleanup(&a);
    result = dns_db_find(db, name, NULL, dns_rdatatype_a,
             DNS_DBFIND_GLUEOK, 0, foundname, &a, NULL);
  }
  if (result == ISC_R_SUCCESS) {
    SET_IF_NOT_NULL(has_a, true);
    dns_rdataset_disassociate(&a);
    if (has_aaaa != NULL && !*has_aaaa) {
      result = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
               DNS_DBFIND_GLUEOK, 0, foundname,
               &aaaa, NULL);
      if (result == ISC_R_SUCCESS) {
        *has_aaaa = true;
      }
      dns_rdataset_cleanup(&aaaa);
    }
    return true;
  } else if (result == DNS_R_GLUE && has_a != NULL) {
    *has_a = true;
  } else if (result == DNS_R_DELEGATION) {
    dns_rdataset_disassociate(&a);
  }

  if (result == DNS_R_NXRRSET || result == DNS_R_DELEGATION ||
      result == DNS_R_GLUE)
  {
    tresult = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
              DNS_DBFIND_GLUEOK, 0, foundname, &aaaa,
              NULL);
    if (tresult == ISC_R_SUCCESS) {
      dns_rdataset_cleanup(&a);
      SET_IF_NOT_NULL(has_aaaa, true);
      dns_rdataset_disassociate(&aaaa);
      return true;
    }
    if (tresult == DNS_R_DELEGATION || tresult == DNS_R_DNAME) {
      dns_rdataset_disassociate(&aaaa);
    }
    if (tresult == DNS_R_GLUE && has_aaaa != NULL) {
      *has_aaaa = true;
    }
    if (result == DNS_R_GLUE || tresult == DNS_R_GLUE) {
      /*
       * Check glue against child zone.
       */
      if (zone->checkns) {
        answer = (zone->ops->checkns)(zone, name, owner,
                    &a, &aaaa);
      }
      dns_rdataset_cleanup(&a);
      dns_rdataset_cleanup(&aaaa);
      return answer;
    }
  }

  dns_name_format(owner, ownerbuf, sizeof ownerbuf);
  dns_name_format(name, namebuf, sizeof namebuf);
  if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
      result == DNS_R_EMPTYNAME || result == DNS_R_DELEGATION)
  {
    const char *what;
    bool required = false;
    if (dns_name_issubdomain(name, owner)) {
      what = "REQUIRED GLUE ";
      required = true;
    } else if (result == DNS_R_DELEGATION) {
      what = "SIBLING GLUE ";
    } else {
      what = "";
    }

    if (result != DNS_R_DELEGATION || required ||
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKSIBLING))
    {
      dns_zone_log(zone, level,
             "%s/NS '%s' has no %s"
             "address records (A or AAAA)",
             ownerbuf, namebuf, what);
      /*
       * Log missing address record.
       */
      if (result == DNS_R_DELEGATION && zone->checkns) {
        (void)(zone->ops->checkns)(zone, name, owner,
                 &a, &aaaa);
      }
      /* XXX950 make fatal for 9.5.0. */
      /* answer = false; */
    }
  } else if (result == DNS_R_CNAME) {
    dns_zone_log(zone, level, "%s/NS '%s' is a CNAME (illegal)",
           ownerbuf, namebuf);
    /* XXX950 make fatal for 9.5.0. */
    /* answer = false; */
  } else if (result == DNS_R_DNAME) {
    dns_name_format(foundname, altbuf, sizeof altbuf);
    dns_zone_log(zone, level,
           "%s/NS '%s' is below a DNAME '%s' (illegal)",
           ownerbuf, namebuf, altbuf);
    /* XXX950 make fatal for 9.5.0. */
    /* answer = false; */
  }

  dns_rdataset_cleanup(&a);
  dns_rdataset_cleanup(&aaaa);
  return answer;
}

static bool
zone_rrset_check_dup(dns_zone_t *zone, dns_name_t *owner,
         dns_rdataset_t *rdataset) {
  dns_rdataset_t tmprdataset;
  bool answer = true;
  bool format = true;
  int level = ISC_LOG_WARNING;
  char ownerbuf[DNS_NAME_FORMATSIZE];
  char typebuf[DNS_RDATATYPE_FORMATSIZE];
  unsigned int count1 = 0;

  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKDUPRRFAIL)) {
    level = ISC_LOG_ERROR;
  }

  dns_rdataset_init(&tmprdataset);
  DNS_RDATASET_FOREACH(rdataset) {
    dns_rdata_t rdata1 = DNS_RDATA_INIT;
    unsigned int count2 = 0;

    count1++;
    dns_rdataset_current(rdataset, &rdata1);
    dns_rdataset_clone(rdataset, &tmprdataset);
    DNS_RDATASET_FOREACH(&tmprdataset) {
      dns_rdata_t rdata2 = DNS_RDATA_INIT;
      count2++;
      if (count1 >= count2) {
        continue;
      }
      dns_rdataset_current(&tmprdataset, &rdata2);
      if (dns_rdata_casecompare(&rdata1, &rdata2) == 0) {
        if (format) {
          dns_name_format(owner, ownerbuf,
              sizeof ownerbuf);
          dns_rdatatype_format(rdata1.type,
                   typebuf,
                   sizeof(typebuf));
          format = false;
        }
        dns_zone_log(zone, level,
               "%s/%s has "
               "semantically identical records",
               ownerbuf, typebuf);
        if (level == ISC_LOG_ERROR) {
          answer = false;
        }
        break;
      }
    }
    dns_rdataset_disassociate(&tmprdataset);
    if (!format) {
      break;
    }
  }
  return answer;
}

static bool
zone_check_dup(dns_zone_t *zone, dns_db_t *db) {
  dns_dbiterator_t *dbiterator = NULL;
  dns_dbnode_t *node = NULL;
  dns_fixedname_t fixed;
  dns_name_t *name = dns_fixedname_initname(&fixed);
  dns_rdatasetiter_t *rdsit = NULL;
  bool ok = true;
  isc_result_t result;

  result = dns_db_createiterator(db, 0, &dbiterator);
  if (result != ISC_R_SUCCESS) {
    return true;
  }

  DNS_DBITERATOR_FOREACH(dbiterator) {
    result = dns_dbiterator_current(dbiterator, &node, name);
    if (result != ISC_R_SUCCESS) {
      continue;
    }

    result = dns_db_allrdatasets(db, node, NULL, 0, 0, &rdsit);
    if (result != ISC_R_SUCCESS) {
      continue;
    }

    DNS_RDATASETITER_FOREACH(rdsit) {
      dns_rdataset_t rdataset = DNS_RDATASET_INIT;
      dns_rdatasetiter_current(rdsit, &rdataset);
      if (!zone_rrset_check_dup(zone, name, &rdataset)) {
        ok = false;
      }
      dns_rdataset_disassociate(&rdataset);
    }
    dns_rdatasetiter_destroy(&rdsit);
    dns_db_detachnode(&node);
  }

  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  dns_dbiterator_destroy(&dbiterator);

  return ok;
}

static bool
isspf(const dns_rdata_t *rdata) {
  char buf[1024];
  const char *tail;
  const unsigned char *data = rdata->data;
  unsigned int rdl = rdata->length, i = 0, tl, len;

  while (rdl > 0U) {
    len = tl = *data;
    ++data;
    --rdl;
    INSIST(tl <= rdl);
    if (len > sizeof(buf) - i - 1) {
      len = sizeof(buf) - i - 1;
    }
    memmove(buf + i, data, len);
    i += len;
    data += tl;
    rdl -= tl;
  }

  if (i < 6U) {
    return false;
  }

  buf[i] = 0;
  tail = isc_string_stripprefix(buf, "v=spf1");
  if (tail != NULL && (*tail == 0 || *tail == ' ')) {
    return true;
  }
  return false;
}

static bool
zone_is_served_by(dns_zone_t *zone, dns_db_t *db, dns_rdatatype_t type,
      dns_name_t *name) {
  dns_rdataset_t rdataset;
  dns_fixedname_t found;
  dns_name_t *foundname = dns_fixedname_initname(&found);
  isc_result_t result;

  /*
   * Outside of zone, assume good when loading in named.
   */
  if (!dns_name_issubdomain(name, &zone->origin)) {
    if (zone->checkns) {
      return zone->ops->checkisservedby(zone, type, name);
    }
    return true;
  }

  dns_rdataset_init(&rdataset);
  result = dns_db_find(db, name, NULL, type, 0, 0, foundname, &rdataset,
           NULL);
  dns_rdataset_cleanup(&rdataset);
  switch (result) {
  case DNS_R_DELEGATION:
    if (zone->checkns) {
      return zone->ops->checkisservedby(zone, type, name);
    }
    /*
     * Treat as success.
     */
    return true;
  case ISC_R_SUCCESS:
    return true;
  default:
    return false;
  }
}

static bool
integrity_checks(dns_zone_t *zone, dns_db_t *db) {
  dns_dbiterator_t *dbiterator = NULL;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset = DNS_RDATASET_INIT;
  dns_fixedname_t fixed;
  dns_fixedname_t fixedbottom;
  dns_name_t *name = dns_fixedname_initname(&fixed);
  dns_name_t *bottom = dns_fixedname_initname(&fixedbottom);
  dns_rdata_mx_t mx;
  dns_rdata_ns_t ns;
  dns_rdata_in_srv_t srv;
  isc_result_t result;
  bool ok = true;
  bool has_a = false, has_aaaa = false;
  char namebuf[DNS_NAME_FORMATSIZE];
  bool logged_algorithm[DST_MAX_ALGS];
  bool logged_digest_type[DNS_DSDIGEST_MAX + 1];

  result = dns_db_createiterator(db, 0, &dbiterator);
  if (result != ISC_R_SUCCESS) {
    return true;
  }

  DNS_DBITERATOR_FOREACH(dbiterator) {
    bool have_ns = false, have_deleg = false;
    bool have_spf = false, have_txt = false;

    CHECK(dns_dbiterator_current(dbiterator, &node, name));

    /*
     * Is this name visible in the zone?
     */
    if (!dns_name_issubdomain(name, &zone->origin) ||
        (!dns_name_empty(bottom) &&
         dns_name_issubdomain(name, bottom)))
    {
      goto next;
    }

    dns_dbiterator_pause(dbiterator);

    /*
     * Check for deprecated KEY algorithms
     */
    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_key,
               0, 0, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checkforns;
    }

    memset(logged_algorithm, 0, sizeof(logged_algorithm));
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdata_key_t key;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &key);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);

      /*
       * If we ever deprecate a private algorithm use
       * dst_algorithm_fromdata() here.
       */
      switch (key.algorithm) {
      case DNS_KEYALG_RSASHA1:
      case DNS_KEYALG_NSEC3RSASHA1:
        if (!logged_algorithm[key.algorithm]) {
          char algbuf[DNS_SECALG_FORMATSIZE];
          dns_name_format(name, namebuf,
              sizeof(namebuf));
          dns_secalg_format(key.algorithm, algbuf,
                sizeof(algbuf));
          dnssec_log(zone, ISC_LOG_WARNING,
               "%s/KEY deprecated "
               "algorithm %u (%s)",
               namebuf, key.algorithm,
               algbuf);
          logged_algorithm[key.algorithm] = true;
        }
        break;
      default:
        break;
      }
    }
    dns_rdataset_disassociate(&rdataset);

  checkforns:
    /*
     * Skip checking NS records at the apex.
     */
    if (dns_name_equal(name, &zone->origin)) {
      goto checkfordeleg;
    }

    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_ns,
               0, 0, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checkfordeleg;
    }

    /*
     * Remember bottom of zone due to NS.
     */
    dns_name_copy(name, bottom);
    have_ns = true;

    /* Check glue correctness */
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &ns);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (!zone_check_glue(zone, db, &has_a, &has_aaaa,
               &ns.name, name))
      {
        ok = false;
      }
    }
    dns_rdataset_disassociate(&rdataset);

  checkfordeleg:
    result = dns_db_findrdataset(db, node, NULL,
               dns_rdatatype_deleg, 0, 0,
               &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checkfords;
    }

    /* DELEG is not allowed at the apex and is class-IN only. */
    if (dns_name_equal(name, &zone->origin)) {
      dns_name_format(name, namebuf, sizeof(namebuf));
      dns_zone_log(zone, ISC_LOG_ERROR,
             "DELEG at zone apex (%s)", namebuf);
      dns_rdataset_disassociate(&rdataset);
      ok = false;
      goto checkfords;
    } else if (zone->rdclass != dns_rdataclass_in) {
      dns_zone_log(zone, ISC_LOG_ERROR, "DELEG: bad class");
      ok = false;
      goto checkfords;
    }

    /*
     * check the DELEG rrset for server-name and
     * include-delegparam paramters, and reject if they're
     * below the owner name.
     */
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);
      dns_fixedname_t fbad;
      dns_name_t *bad = dns_fixedname_initname(&fbad);

      if (!dns_rdata_checknames(&rdata, name, bad)) {
        dns_name_format(bad, namebuf, sizeof(namebuf));
        dns_zone_log(zone, ISC_LOG_ERROR,
               "DELEG: invalid target name '%s'",
               namebuf);
        ok = false;
        dns_rdataset_disassociate(&rdataset);
        goto checkfords;
      }
    }

    /*
     * Remember bottom of zone due to DELEG.
     */
    dns_name_copy(name, bottom);
    have_deleg = true;
    dns_rdataset_disassociate(&rdataset);

  checkfords:
    /*
     * DS is only allowed at a delegation point (i.e.,
     * coexisting with NS or DELEG and not at the apex).
     */
    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_ds,
               0, 0, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checkfordname;
    }

    if (!have_ns && !have_deleg) {
      int level = ISC_LOG_WARNING;
      if (zone->type == dns_zone_primary) {
        level = ISC_LOG_ERROR;
        ok = false;
      }
      dns_name_format(name, namebuf, sizeof(namebuf));
      dns_zone_log(zone, level,
             "DS not at delegation point (%s)",
             namebuf);
      dns_rdataset_disassociate(&rdataset);
      goto checkfordname;
    }

    /*
     * Check for deprecated DS digest types.
     */
    memset(logged_algorithm, 0, sizeof(logged_algorithm));
    memset(logged_digest_type, 0, sizeof(logged_digest_type));
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);
      dns_rdata_ds_t ds;

      result = dns_rdata_tostruct(&rdata, &ds);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      switch (ds.digest_type) {
      case DNS_DSDIGEST_SHA1:
      case DNS_DSDIGEST_GOST:
        if (!logged_digest_type[ds.digest_type]) {
          char algbuf[DNS_DSDIGEST_FORMATSIZE];
          dns_name_format(name, namebuf,
              sizeof(namebuf));
          dns_dsdigest_format(ds.digest_type,
                  algbuf,
                  sizeof(algbuf));
          dnssec_log(zone, ISC_LOG_WARNING,
               "%s/DS deprecated digest "
               "type %u (%s)",
               namebuf, ds.digest_type,
               algbuf);
          logged_digest_type[ds.digest_type] =
            true;
        }
        break;
      }

      /*
       * If we ever deprecate a private algorithm use
       * dst_algorithm_fromdata() here.
       */
      switch (ds.algorithm) {
      case DNS_KEYALG_RSASHA1:
      case DNS_KEYALG_NSEC3RSASHA1:
        if (!logged_algorithm[ds.algorithm]) {
          char algbuf[DNS_SECALG_FORMATSIZE];
          dns_name_format(name, namebuf,
              sizeof(namebuf));
          dns_secalg_format(ds.algorithm, algbuf,
                sizeof(algbuf));
          dnssec_log(zone, ISC_LOG_WARNING,
               "%s/DS deprecated algorithm "
               "%u (%s)",
               namebuf, ds.algorithm,
               algbuf);
          logged_algorithm[ds.algorithm] = true;
        }
        break;
      }
    }
    dns_rdataset_disassociate(&rdataset);

  checkfordname:
    result = dns_db_findrdataset(db, node, NULL,
               dns_rdatatype_dname, 0, 0,
               &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checkformx;
    }

    /*
     * Remember bottom of zone due to DNAME.
     */
    dns_name_copy(name, bottom);
    dns_rdataset_disassociate(&rdataset);

  checkformx:
    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_mx,
               0, 0, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checksrv;
    }
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &mx);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (!zone_check_mx(zone, db, &mx.mx, name)) {
        ok = false;
      }
    }
    dns_rdataset_disassociate(&rdataset);

  checksrv:
    if (zone->rdclass != dns_rdataclass_in) {
      /* All the remaining tests are for class IN only */
      goto next;
    }
    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_srv,
               0, 0, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto checkforaaaa;
    }
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &srv);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (!zone_check_srv(zone, db, &srv.target, name)) {
        ok = false;
      }
    }
    dns_rdataset_disassociate(&rdataset);

  checkforaaaa:
    /*
     * Check if there is an A or AAAA RRset anywhere in
     * the zone.
     */
    if (!has_a) {
      result = dns_db_findrdataset(db, node, NULL,
                 dns_rdatatype_a, 0, 0,
                 &rdataset, NULL);
      if (result == ISC_R_SUCCESS) {
        has_a = true;
        dns_rdataset_disassociate(&rdataset);
      }
    }
    if (!has_aaaa) {
      result = dns_db_findrdataset(db, node, NULL,
                 dns_rdatatype_aaaa, 0, 0,
                 &rdataset, NULL);
      if (result == ISC_R_SUCCESS) {
        has_aaaa = true;
        dns_rdataset_disassociate(&rdataset);
      }
    }

    /*
     * Check if there is a type SPF record without an
     * SPF-formatted type TXT record also being present.
     */
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKSPF)) {
      goto next;
    }
    if (zone->rdclass != dns_rdataclass_in) {
      goto next;
    }

    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_spf,
               0, 0, &rdataset, NULL);
    if (result == ISC_R_SUCCESS) {
      dns_rdataset_disassociate(&rdataset);
      have_spf = true;
    }
    result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_txt,
               0, 0, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      goto notxt;
    }
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      have_txt = isspf(&rdata);
      if (have_txt) {
        break;
      }
    }
    dns_rdataset_disassociate(&rdataset);

  notxt:
    if (have_spf && !have_txt) {
      dns_name_format(name, namebuf, sizeof(namebuf));
      dns_zone_log(zone, ISC_LOG_WARNING,
             "'%s' found type "
             "SPF record but no SPF TXT record found, "
             "add matching type TXT record",
             namebuf);
    }

  next:
    dns_db_detachnode(&node);
  }

  if (has_a) {
    has_a = false;
    result = dns_db_find(db, &zone->origin, NULL, dns_rdatatype_ns,
             0, 0, name, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      dns_rdataset_cleanup(&rdataset);
      goto cleanup;
    }

    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &ns);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (zone_is_served_by(zone, db, dns_rdatatype_a,
                &ns.name))
      {
        has_a = true;
        break;
      }
    }
    dns_rdataset_disassociate(&rdataset);
    if (!has_a) {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "zone has A records but is not served "
             "by IPv4 servers");
    }
  }

  if (has_aaaa) {
    has_aaaa = false;
    result = dns_db_find(db, &zone->origin, NULL, dns_rdatatype_ns,
             0, 0, name, &rdataset, NULL);
    if (result != ISC_R_SUCCESS) {
      dns_rdataset_cleanup(&rdataset);
      goto cleanup;
    }

    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &ns);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (zone_is_served_by(zone, db, dns_rdatatype_aaaa,
                &ns.name))
      {
        has_aaaa = true;
        break;
      }
    }
    dns_rdataset_disassociate(&rdataset);
    if (!has_aaaa) {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "zone has AAAA records but is not served "
             "by IPv6 servers");
    }
  }

cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  dns_dbiterator_destroy(&dbiterator);

  return ok;
}

/*
 * OpenSSL verification of RSA keys with exponent 3 is known to be
 * broken prior OpenSSL 0.9.8c/0.9.7k.  Look for such keys and warn
 * if they are in use.
 */
static void
zone_check_dnskeys(dns_zone_t *zone, dns_db_t *db) {
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_rdata_dnskey_t dnskey;
  dns_rdataset_t rdataset;
  isc_result_t result;
  bool logged_algorithm[DST_MAX_ALGS] = { 0 };
  bool alldeprecated = true;

  CHECK(dns_db_findnode(db, &zone->origin, false, &node));

  dns_db_currentversion(db, &version);
  dns_rdataset_init(&rdataset);
  CHECK(dns_db_findrdataset(db, node, version, dns_rdatatype_dnskey,
          dns_rdatatype_none, 0, &rdataset, NULL));

  DNS_RDATASET_FOREACH(&rdataset) {
    char algbuf[DNS_SECALG_FORMATSIZE];
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &dnskey);
    INSIST(result == ISC_R_SUCCESS);

    /*
     * RFC 3110, section 4: Performance Considerations:
     *
     * A public exponent of 3 minimizes the effort needed to verify
     * a signature.  Use of 3 as the public exponent is weak for
     * confidentiality uses since, if the same data can be collected
     * encrypted under three different keys with an exponent of 3
     * then, using the Chinese Remainder Theorem [NETSEC], the
     * original plain text can be easily recovered.  If a key is
     * known to be used only for authentication, as is the case with
     * DNSSEC, then an exponent of 3 is acceptable.  However other
     * applications in the future may wish to leverage DNS
     * distributed keys for applications that do require
     * confidentiality.  For keys which might have such other uses,
     * a more conservative choice would be 65537 (F4, the fourth
     * fermat number).
     */
    if (dnskey.datalen > 1 && dnskey.data[0] == 1 &&
        dnskey.data[1] == 3 &&
        (dnskey.algorithm == DNS_KEYALG_RSAMD5 ||
         dnskey.algorithm == DNS_KEYALG_RSASHA1 ||
         dnskey.algorithm == DNS_KEYALG_NSEC3RSASHA1 ||
         dnskey.algorithm == DNS_KEYALG_RSASHA256 ||
         dnskey.algorithm == DNS_KEYALG_RSASHA512))
    {
      char algorithm[DNS_SECALG_FORMATSIZE];
      isc_region_t r;

      dns_rdata_toregion(&rdata, &r);
      dns_secalg_format(dnskey.algorithm, algorithm,
            sizeof(algorithm));

      dnssec_log(zone, ISC_LOG_WARNING,
           "weak %s (%u) key found (exponent=3, id=%u)",
           algorithm, dnskey.algorithm,
           dst_region_computeid(&r));
    }
    switch (dnskey.algorithm) {
    case DNS_KEYALG_RSAMD5:
    case DNS_KEYALG_DSA:
    case DNS_KEYALG_RSASHA1:
    case DNS_KEYALG_NSEC3DSA:
    case DNS_KEYALG_NSEC3RSASHA1:
    case DNS_KEYALG_ECCGOST:
      if (!logged_algorithm[dnskey.algorithm]) {
        dns_secalg_format(dnskey.algorithm, algbuf,
              sizeof(algbuf));
        dnssec_log(zone, ISC_LOG_WARNING,
             "deprecated DNSKEY algorithm found: "
             "%u (%s)\n",
             dnskey.algorithm, algbuf);
        logged_algorithm[dnskey.algorithm] = true;
      }
      break;
    default:
      alldeprecated = false;
      break;
    }
  }
  dns_rdataset_disassociate(&rdataset);

  if (alldeprecated) {
    dnssec_log(zone, ISC_LOG_WARNING,
         "all DNSKEY algorithms found are deprecated");
  }

cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
  }
}

static void
resume_signingwithkey(dns_zone_t *zone) {
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_rdataset_t rdataset;
  isc_result_t result;
  dns_db_t *db = NULL;

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    goto cleanup;
  }

  CHECK(dns_db_findnode(db, &zone->origin, false, &node));

  dns_db_currentversion(db, &version);
  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, version, zone->privatetype,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dst_algorithm_t alg;

    dns_rdataset_current(&rdataset, &rdata);
    /*
     * Old or New Forms
     */
    if ((rdata.length != OLD_SIGNING_RECORD_SIZE &&
         rdata.length != SIGNING_RECORD_SIZE) ||
        rdata.data[0] == 0 || rdata.data[4] != 0)
    {
      continue;
    }
    alg = (rdata.length == OLD_SIGNING_RECORD_SIZE)
            ? rdata.data[0]
            : ((rdata.data[5] << 8) | rdata.data[6]);
    result = zone_signwithkey(zone, alg,
            (rdata.data[1] << 8) | rdata.data[2],
            rdata.data[3], false);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_signwithkey failed: %s",
           isc_result_totext(result));
    }
  }
  dns_rdataset_disassociate(&rdataset);

cleanup:
  if (db != NULL) {
    if (node != NULL) {
      dns_db_detachnode(&node);
    }
    if (version != NULL) {
      dns_db_closeversion(db, &version, false);
    }
    dns_db_detach(&db);
  }
}

/*
 * Initiate adding/removing NSEC3 records belonging to the chain defined by the
 * supplied NSEC3PARAM RDATA.
 *
 * Zone must be locked by caller.
 */
static isc_result_t
zone_addnsec3chain(dns_zone_t *zone, dns_rdata_nsec3param_t *nsec3param) {
  dns_nsec3chain_t *nsec3chain;
  dns_dbversion_t *version = NULL;
  bool nseconly = false, nsec3ok = false;
  isc_result_t result;
  isc_time_t now;
  unsigned int options = 0;
  char saltbuf[255 * 2 + 1];
  char flags[sizeof("INITIAL|REMOVE|CREATE|NONSEC|OPTOUT")];
  dns_db_t *db = NULL;

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

  if (db == NULL) {
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  /*
   * If this zone is not NSEC3-capable, attempting to remove any NSEC3
   * chain from it is pointless as it would not be possible for the
   * latter to exist in the first place.
   */
  dns_db_currentversion(db, &version);
  result = dns_nsec_nseconly(db, version, NULL, &nseconly);
  nsec3ok = (result == ISC_R_SUCCESS && !nseconly);
  dns_db_closeversion(db, &version, false);
  if (!nsec3ok && (nsec3param->flags & DNS_NSEC3FLAG_REMOVE) == 0) {
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  /*
   * Allocate and initialize structure preserving state of
   * adding/removing records belonging to this NSEC3 chain between
   * separate zone_nsec3chain() calls.
   */
  nsec3chain = isc_mem_get(zone->mctx, sizeof *nsec3chain);

  nsec3chain->magic = 0;
  nsec3chain->done = false;
  nsec3chain->db = NULL;
  nsec3chain->dbiterator = NULL;
  nsec3chain->nsec3param.common.rdclass = nsec3param->common.rdclass;
  nsec3chain->nsec3param.common.rdtype = nsec3param->common.rdtype;
  nsec3chain->nsec3param.hash = nsec3param->hash;
  nsec3chain->nsec3param.iterations = nsec3param->iterations;
  nsec3chain->nsec3param.flags = nsec3param->flags;
  nsec3chain->nsec3param.salt.length = nsec3param->salt.length;
  memmove(nsec3chain->salt, nsec3param->salt.base,
    nsec3param->salt.length);
  nsec3chain->nsec3param.salt.base = nsec3chain->salt;
  nsec3chain->seen_nsec = false;
  nsec3chain->delete_nsec = false;
  nsec3chain->save_delete_nsec = false;

  /*
   * Log NSEC3 parameters defined by supplied NSEC3PARAM RDATA.
   */
  if (nsec3param->flags == 0) {
    strlcpy(flags, "NONE", sizeof(flags));
  } else {
    flags[0] = '\0';
    if ((nsec3param->flags & DNS_NSEC3FLAG_REMOVE) != 0) {
      strlcat(flags, "REMOVE", sizeof(flags));
    }
    if ((nsec3param->flags & DNS_NSEC3FLAG_INITIAL) != 0) {
      if (flags[0] == '\0') {
        strlcpy(flags, "INITIAL", sizeof(flags));
      } else {
        strlcat(flags, "|INITIAL", sizeof(flags));
      }
    }
    if ((nsec3param->flags & DNS_NSEC3FLAG_CREATE) != 0) {
      if (flags[0] == '\0') {
        strlcpy(flags, "CREATE", sizeof(flags));
      } else {
        strlcat(flags, "|CREATE", sizeof(flags));
      }
    }
    if ((nsec3param->flags & DNS_NSEC3FLAG_NONSEC) != 0) {
      if (flags[0] == '\0') {
        strlcpy(flags, "NONSEC", sizeof(flags));
      } else {
        strlcat(flags, "|NONSEC", sizeof(flags));
      }
    }
    if ((nsec3param->flags & DNS_NSEC3FLAG_OPTOUT) != 0) {
      if (flags[0] == '\0') {
        strlcpy(flags, "OPTOUT", sizeof(flags));
      } else {
        strlcat(flags, "|OPTOUT", sizeof(flags));
      }
    }
  }
  result = dns_nsec3param_salttotext(nsec3param, saltbuf,
             sizeof(saltbuf));
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
  dnssec_log(zone, ISC_LOG_INFO, "zone_addnsec3chain(%u,%s,%u,%s)",
       nsec3param->hash, flags, nsec3param->iterations, saltbuf);

  /*
   * If the NSEC3 chain defined by the supplied NSEC3PARAM RDATA is
   * currently being processed, interrupt its processing to avoid
   * simultaneously adding and removing records for the same NSEC3 chain.
   */
  ISC_LIST_FOREACH(zone->nsec3chain, current, link) {
    if ((current->db == db) &&
        (current->nsec3param.hash == nsec3param->hash) &&
        (current->nsec3param.iterations ==
         nsec3param->iterations) &&
        (current->nsec3param.salt.length ==
         nsec3param->salt.length) &&
        memcmp(current->nsec3param.salt.base, nsec3param->salt.base,
         nsec3param->salt.length) == 0)
    {
      current->done = true;
    }
  }

  /*
   * Attach zone database to the structure initialized above and create
   * an iterator for it with appropriate options in order to avoid
   * creating NSEC3 records for NSEC3 records.
   */
  dns_db_attach(db, &nsec3chain->db);
  if ((nsec3chain->nsec3param.flags & DNS_NSEC3FLAG_CREATE) != 0) {
    options = DNS_DB_NONSEC3;
  }
  result = dns_db_createiterator(nsec3chain->db, options,
               &nsec3chain->dbiterator);
  if (result == ISC_R_SUCCESS) {
    result = dns_dbiterator_first(nsec3chain->dbiterator);
  }
  if (result == ISC_R_SUCCESS) {
    /*
     * Database iterator initialization succeeded.  We are now
     * ready to kick off adding/removing records belonging to this
     * NSEC3 chain.  Append the structure initialized above to the
     * "nsec3chain" list for the zone and set the appropriate zone
     * timer so that zone_nsec3chain() is called as soon as
     * possible.
     */
    dns_dbiterator_pause(nsec3chain->dbiterator);
    ISC_LIST_INITANDAPPEND(zone->nsec3chain, nsec3chain, link);
    nsec3chain = NULL;
    if (isc_time_isepoch(&zone->nsec3chaintime)) {
      now = isc_time_now();
      zone->nsec3chaintime = now;
      if (zone->loop != NULL) {
        dns__zone_settimer(zone, now);
      }
    }
  }

  if (nsec3chain != NULL) {
    if (nsec3chain->db != NULL) {
      dns_db_detach(&nsec3chain->db);
    }
    if (nsec3chain->dbiterator != NULL) {
      dns_dbiterator_destroy(&nsec3chain->dbiterator);
    }
    isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
  }

cleanup:
  if (db != NULL) {
    dns_db_detach(&db);
  }
  return result;
}

/*
 * Find private-type records at the zone apex which signal that an NSEC3 chain
 * should be added or removed.  For each such record, extract NSEC3PARAM RDATA
 * and pass it to zone_addnsec3chain().
 *
 * Zone must be locked by caller.
 */
static void
resume_addnsec3chain(dns_zone_t *zone) {
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_rdataset_t rdataset;
  isc_result_t result;
  dns_rdata_nsec3param_t nsec3param;
  bool nseconly = false, nsec3ok = false;
  dns_db_t *db = NULL;

  INSIST(LOCKED_ZONE(zone));

  if (zone->privatetype == 0) {
    return;
  }

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    goto cleanup;
  }

  CHECK(dns_db_findnode(db, &zone->origin, false, &node));

  dns_db_currentversion(db, &version);

  /*
   * In order to create NSEC3 chains we need the DNSKEY RRset at zone
   * apex to exist and contain no keys using NSEC-only algorithms.
   */
  result = dns_nsec_nseconly(db, version, NULL, &nseconly);
  nsec3ok = (result == ISC_R_SUCCESS && !nseconly);

  /*
   * Get the RRset containing all private-type records at the zone apex.
   */
  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, version, zone->privatetype,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_t private = DNS_RDATA_INIT;

    dns_rdataset_current(&rdataset, &private);
    /*
     * Try extracting NSEC3PARAM RDATA from this private-type
     * record.  Failure means this private-type record does not
     * represent an NSEC3PARAM record, so skip it.
     */
    if (!dns_nsec3param_fromprivate(&private, &rdata, buf,
            sizeof(buf)))
    {
      continue;
    }
    result = dns_rdata_tostruct(&rdata, &nsec3param);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    if (((nsec3param.flags & DNS_NSEC3FLAG_REMOVE) != 0) ||
        ((nsec3param.flags & DNS_NSEC3FLAG_CREATE) != 0 && nsec3ok))
    {
      /*
       * Pass the NSEC3PARAM RDATA contained in this
       * private-type record to zone_addnsec3chain() so that
       * it can kick off adding or removing NSEC3 records.
       */
      result = zone_addnsec3chain(zone, &nsec3param);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_addnsec3chain failed: %s",
             isc_result_totext(result));
      }
    }
  }
  dns_rdataset_disassociate(&rdataset);

cleanup:
  if (db != NULL) {
    if (node != NULL) {
      dns_db_detachnode(&node);
    }
    if (version != NULL) {
      dns_db_closeversion(db, &version, false);
    }
    dns_db_detach(&db);
  }
}

void
dns__zone_set_resigntime(dns_zone_t *zone) {
  dns_fixedname_t fixed;
  isc_stdtime_t resign;
  isc_result_t result;
  uint32_t nanosecs;
  dns_db_t *db = NULL;
  dns_typepair_t typepair;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));

  /* We only re-sign zones that can be dynamically updated */
  if (!dns_zone_isdynamic(zone, false)) {
    return;
  }

  if (dns__zone_inline_raw(zone)) {
    return;
  }

  dns_fixedname_init(&fixed);

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    isc_time_settoepoch(&zone->resigntime);
    return;
  }

  result = dns_db_getsigningtime(db, &resign, dns_name(&fixed),
               &typepair);
  if (result != ISC_R_SUCCESS) {
    isc_time_settoepoch(&zone->resigntime);
    goto cleanup;
  }

  resign -= dns_zone_getsigresigninginterval(zone);
  nanosecs = isc_random_uniform(1000000000);
  isc_time_set(&zone->resigntime, resign, nanosecs);

cleanup:
  dns_db_detach(&db);
  return;
}

static isc_result_t
check_nsec3param(dns_zone_t *zone, dns_db_t *db) {
  bool ok = false;
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_rdata_nsec3param_t nsec3param;
  dns_rdataset_t rdataset;
  isc_result_t result;
  bool dynamic = (zone->type == dns_zone_primary)
             ? dns_zone_isdynamic(zone, false)
             : false;

  dns_rdataset_init(&rdataset);
  result = dns_db_findnode(db, &zone->origin, false, &node);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "nsec3param lookup failure: %s",
           isc_result_totext(result));
    return result;
  }
  dns_db_currentversion(db, &version);

  result = dns_db_findrdataset(db, node, version,
             dns_rdatatype_nsec3param,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    result = ISC_R_SUCCESS;
    goto cleanup;
  }
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    dns_zone_log(zone, ISC_LOG_ERROR,
           "nsec3param lookup failure: %s",
           isc_result_totext(result));
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(&rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &nsec3param);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    /*
     * For dynamic zones we must support every algorithm so we
     * can regenerate all the NSEC3 chains.
     * For non-dynamic zones we only need to find a supported
     * algorithm.
     */
    if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NSEC3TESTZONE) &&
        nsec3param.hash == DNS_NSEC3_UNKNOWNALG && !dynamic)
    {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "nsec3 test \"unknown\" hash algorithm "
             "found: %u",
             nsec3param.hash);
      ok = true;
    } else if (!dns_nsec3_supportedhash(nsec3param.hash)) {
      if (dynamic) {
        dns_zone_log(zone, ISC_LOG_ERROR,
               "unsupported nsec3 hash algorithm"
               " in dynamic zone: %u",
               nsec3param.hash);
        result = DNS_R_BADZONE;
        /* Stop second error message. */
        ok = true;
        break;
      } else {
        dns_zone_log(zone, ISC_LOG_WARNING,
               "unsupported nsec3 hash "
               "algorithm: %u",
               nsec3param.hash);
      }
    } else {
      ok = true;
    }

    /*
     * Warn if the zone has excessive NSEC3 iterations.
     */
    if (nsec3param.iterations > dns_nsec3_maxiterations()) {
      dnssec_log(zone, ISC_LOG_WARNING,
           "excessive NSEC3PARAM iterations %u > %u",
           nsec3param.iterations,
           dns_nsec3_maxiterations());
    }
  }

  if (!ok) {
    result = DNS_R_BADZONE;
    dns_zone_log(zone, ISC_LOG_ERROR,
           "no supported nsec3 hash algorithm");
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  dns_db_closeversion(db, &version, false);
  dns_db_detachnode(&node);
  return result;
}

/*
 * Set the timer for refreshing the key zone to the soonest future time
 * of the set (current timer, keydata->refresh, keydata->addhd,
 * keydata->removehd).
 */
static void
set_refreshkeytimer(dns_zone_t *zone, dns_rdata_keydata_t *key,
        isc_stdtime_t now, bool force) {
  isc_stdtime_t then;
  isc_time_t timenow, timethen;
  char timebuf[80];

  ENTER;
  then = key->refresh;
  if (force) {
    then = now;
  }
  if (key->addhd > now && key->addhd < then) {
    then = key->addhd;
  }
  if (key->removehd > now && key->removehd < then) {
    then = key->removehd;
  }

  timenow = isc_time_now();
  if (then > now) {
    DNS_ZONE_TIME_ADD(&timenow, then - now, &timethen);
  } else {
    timethen = timenow;
  }
  if (isc_time_compare(&zone->refreshkeytime, &timenow) < 0 ||
      isc_time_compare(&timethen, &zone->refreshkeytime) < 0)
  {
    zone->refreshkeytime = timethen;
  }

  isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
  dns_zone_log(zone, ISC_LOG_DEBUG(1), "next key refresh: %s", timebuf);
  dns__zone_settimer(zone, timenow);
}

/*
 * If keynode references a key or a DS rdataset, and if the key
 * zone does not contain a KEYDATA record for the corresponding name,
 * then create an empty KEYDATA and push it into the zone as a placeholder,
 * then schedule a key refresh immediately. This new KEYDATA record will be
 * updated during the refresh.
 *
 * If the key zone is changed, set '*changed' to true.
 */
static isc_result_t
create_keydata(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
         dns_diff_t *diff, dns_keynode_t *keynode, dns_name_t *keyname,
         bool *changed) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_rdata_keydata_t kd;
  unsigned char rrdata[4096];
  isc_buffer_t rrdatabuf;
  isc_stdtime_t now = isc_stdtime_now();

  REQUIRE(keynode != NULL);

  ENTER;

  /*
   * If the keynode has no trust anchor set, we shouldn't be here.
   */
  if (!dns_keynode_dsset(keynode, NULL)) {
    return ISC_R_FAILURE;
  }

  memset(&kd, 0, sizeof(kd));
  kd.common.rdclass = zone->rdclass;
  kd.common.rdtype = dns_rdatatype_keydata;

  isc_buffer_init(&rrdatabuf, rrdata, sizeof(rrdata));

  CHECK(dns_rdata_fromstruct(&rdata, zone->rdclass, dns_rdatatype_keydata,
           &kd, &rrdatabuf));
  /* Add rdata to zone. */
  CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADD, keyname, 0, &rdata));
  *changed = true;

  /* Refresh new keys from the zone apex as soon as possible. */
  set_refreshkeytimer(zone, &kd, now, true);
  return ISC_R_SUCCESS;

cleanup:
  return result;
}

/*
 * Remove from the key zone all the KEYDATA records found in rdataset.
 */
static isc_result_t
delete_keydata(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
         dns_name_t *name, dns_rdataset_t *rdataset) {
  DNS_RDATASET_FOREACH(rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(rdataset, &rdata);
    RETERR(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name, 0,
             &rdata));
  }

  return ISC_R_SUCCESS;
}

/*
 * Compute the DNSSEC key ID for a DNSKEY record.
 */
static isc_result_t
compute_tag(dns_rdata_dnskey_t *dnskey, dns_keytag_t *tag) {
  isc_result_t result;
  isc_region_t r;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  unsigned char data[DNS_RDATA_MAXLENGTH];
  isc_buffer_t buffer;

  isc_buffer_init(&buffer, data, sizeof(data));

  CHECK(dns_rdata_fromstruct(&rdata, dnskey->common.rdclass,
           dns_rdatatype_dnskey, dnskey, &buffer));
  dns_rdata_toregion(&rdata, &r);
  *tag = dst_region_computeid(&r);

cleanup:
  return result;
}

/*
 * Synth-from-dnssec callbacks to add/delete names from namespace tree.
 */
static void
sfd_add(const dns_name_t *name, void *arg) {
  if (arg != NULL) {
    dns_view_sfd_add(arg, name);
  }
}

static void
sfd_del(const dns_name_t *name, void *arg) {
  if (arg != NULL) {
    dns_view_sfd_del(arg, name);
  }
}

/*
 * Add key to the security roots.
 */
static void
trust_key(dns_zone_t *zone, dns_name_t *keyname, dns_rdata_dnskey_t *dnskey,
    bool initial) {
  isc_result_t result;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  unsigned char data[DNS_RDATA_MAXLENGTH];
  unsigned char digest[DNS_DS_BUFFERSIZE];
  isc_buffer_t buffer;
  dns_keytable_t *sr = NULL;
  dns_rdata_ds_t ds;

  CHECK(dns_view_getsecroots(zone->view, &sr));

  /* Build DS record for key. */
  isc_buffer_init(&buffer, data, sizeof(data));
  CHECK(dns_rdata_fromstruct(&rdata, dnskey->common.rdclass,
           dns_rdatatype_dnskey, dnskey, &buffer));
  CHECK(dns_ds_fromkeyrdata(keyname, &rdata, DNS_DSDIGEST_SHA256, digest,
          sizeof(digest), &ds));
  CHECK(dns_keytable_add(sr, true, initial, keyname, &ds, sfd_add,
             zone->view));

  dns_keytable_detach(&sr);

cleanup:
  if (sr != NULL) {
    dns_keytable_detach(&sr);
  }
  return;
}

/*
 * Add a null key to the security roots for so that all queries
 * to the zone will fail.
 */
static void
fail_secure(dns_zone_t *zone, dns_name_t *keyname) {
  isc_result_t result;
  dns_keytable_t *sr = NULL;

  result = dns_view_getsecroots(zone->view, &sr);
  if (result == ISC_R_SUCCESS) {
    dns_keytable_marksecure(sr, keyname);
    dns_keytable_detach(&sr);
  }
}

/*
 * Scan a set of KEYDATA records from the key zone.  The ones that are
 * valid (i.e., the add holddown timer has expired) become trusted keys.
 */
static void
load_secroots(dns_zone_t *zone, dns_name_t *name, dns_rdataset_t *rdataset) {
  isc_result_t result;
  dns_rdata_keydata_t keydata;
  dns_rdata_dnskey_t dnskey;
  int trusted = 0, revoked = 0, pending = 0;
  isc_stdtime_t now = isc_stdtime_now();
  dns_keytable_t *sr = NULL;

  result = dns_view_getsecroots(zone->view, &sr);
  if (result == ISC_R_SUCCESS) {
    dns_keytable_delete(sr, name, sfd_del, zone->view);
    dns_keytable_detach(&sr);
  }

  /* Now insert all the accepted trust anchors from this keydata set. */
  DNS_RDATASET_FOREACH(rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(rdataset, &rdata);

    /* Convert rdata to keydata. */
    result = dns_rdata_tostruct(&rdata, &keydata);
    if (result == ISC_R_NOTIMPLEMENTED) {
      continue;
    }
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    /* Set the key refresh timer to force a fast refresh. */
    set_refreshkeytimer(zone, &keydata, now, true);

    /* If the removal timer is nonzero, this key was revoked. */
    if (keydata.removehd != 0) {
      revoked++;
      continue;
    }

    /*
     * If the add timer is still pending, this key is not
     * trusted yet.
     */
    if (now < keydata.addhd) {
      pending++;
      continue;
    }

    /* Convert keydata to dnskey. */
    dns_keydata_todnskey(&keydata, &dnskey);

    /* Add to keytables. */
    trusted++;
    trust_key(zone, name, &dnskey, keydata.addhd == 0);
  }

  if (trusted == 0 && pending != 0) {
    char namebuf[DNS_NAME_FORMATSIZE];
    dns_name_format(name, namebuf, sizeof namebuf);
    dnssec_log(zone, ISC_LOG_ERROR,
         "No valid trust anchors for '%s'!", namebuf);
    dnssec_log(zone, ISC_LOG_ERROR,
         "%d key(s) revoked, %d still pending", revoked,
         pending);
    dnssec_log(zone, ISC_LOG_ERROR, "All queries to '%s' will fail",
         namebuf);
    fail_secure(zone, name);
  }
}

static isc_result_t
update_one_rr(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
        dns_diffop_t op, dns_name_t *name, dns_ttl_t ttl,
        dns_rdata_t *rdata) {
  dns_difftuple_t *tuple = NULL;

  dns_difftuple_create(diff->mctx, op, name, ttl, rdata, &tuple);
  return dns_diff_applytuple(&tuple, db, ver, diff);
}

static isc_result_t
update_soa_serial(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
      dns_diff_t *diff, isc_mem_t *mctx,
      dns_updatemethod_t method) {
  dns_difftuple_t *deltuple = NULL;
  dns_difftuple_t *addtuple = NULL;
  uint32_t serial;
  isc_result_t result;
  dns_updatemethod_t used = dns_updatemethod_none;

  INSIST(method != dns_updatemethod_none);

  CHECK(dns_db_createsoatuple(db, ver, mctx, DNS_DIFFOP_DEL, &deltuple));
  dns_difftuple_copy(deltuple, &addtuple);
  addtuple->op = DNS_DIFFOP_ADD;

  serial = dns_soa_getserial(&addtuple->rdata);
  serial = dns_update_soaserial(serial, method, &used);
  if (method != used) {
    dns_zone_log(zone, ISC_LOG_WARNING,
           "update_soa_serial:new serial would be lower than "
           "old serial, using increment method instead");
  }
  dns_soa_setserial(serial, &addtuple->rdata);
  CHECK(dns_diff_applytuple(&deltuple, db, ver, diff));
  CHECK(dns_diff_applytuple(&addtuple, db, ver, diff));
  result = ISC_R_SUCCESS;

cleanup:
  if (addtuple != NULL) {
    dns_difftuple_free(&addtuple);
  }
  if (deltuple != NULL) {
    dns_difftuple_free(&deltuple);
  }
  return result;
}

/*
 * Write all transactions in 'diff' to the zone journal file.
 */
static isc_result_t
zone_journal(dns_zone_t *zone, dns_diff_t *diff, uint32_t *sourceserial,
       const char *caller) {
  const char *journalfile;
  isc_result_t result = ISC_R_SUCCESS;
  dns_journal_t *journal = NULL;
  unsigned int mode = DNS_JOURNAL_CREATE | DNS_JOURNAL_WRITE;

  ENTER;
  journalfile = dns_zone_getjournal(zone);
  if (journalfile != NULL) {
    result = dns_journal_open(zone->mctx, journalfile, mode,
            &journal);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "%s:dns_journal_open -> %s", caller,
             isc_result_totext(result));
      return result;
    }

    if (sourceserial != NULL) {
      dns_journal_set_sourceserial(journal, *sourceserial);
    }

    result = dns_journal_write_transaction(journal, diff);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "%s:dns_journal_write_transaction -> %s",
             caller, isc_result_totext(result));
    }
    dns_journal_destroy(&journal);
  }

  return result;
}

/*
 * Create an SOA record for a newly-created zone
 */
static isc_result_t
add_soa(dns_zone_t *zone, dns_db_t *db) {
  isc_result_t result;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  unsigned char buf[DNS_SOA_BUFFERSIZE];
  dns_dbversion_t *ver = NULL;
  dns_diff_t diff;

  dns_zone_log(zone, ISC_LOG_DEBUG(1), "creating SOA");

  dns_diff_init(zone->mctx, &diff);
  result = dns_db_newversion(db, &ver);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "add_soa:dns_db_newversion -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  /* Build SOA record */
  result = dns_soa_buildrdata(&zone->origin, dns_rootname, zone->rdclass,
            0, 0, 0, 0, 0, buf, &rdata);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "add_soa:dns_soa_buildrdata -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  result = update_one_rr(db, ver, &diff, DNS_DIFFOP_ADD, &zone->origin, 0,
             &rdata);

cleanup:
  dns_diff_clear(&diff);
  if (ver != NULL) {
    dns_db_closeversion(db, &ver, result == ISC_R_SUCCESS);
  }

  INSIST(ver == NULL);

  return result;
}

struct addifmissing_arg {
  dns_db_t *db;
  dns_dbversion_t *ver;
  dns_diff_t *diff;
  dns_zone_t *zone;
  bool *changed;
  isc_result_t result;
};

static void
addifmissing(dns_keytable_t *keytable, dns_keynode_t *keynode,
       dns_name_t *keyname, void *arg) {
  dns_db_t *db = ((struct addifmissing_arg *)arg)->db;
  dns_dbversion_t *ver = ((struct addifmissing_arg *)arg)->ver;
  dns_diff_t *diff = ((struct addifmissing_arg *)arg)->diff;
  dns_zone_t *zone = ((struct addifmissing_arg *)arg)->zone;
  bool *changed = ((struct addifmissing_arg *)arg)->changed;
  isc_result_t result;
  dns_fixedname_t fname;

  UNUSED(keytable);

  if (((struct addifmissing_arg *)arg)->result != ISC_R_SUCCESS) {
    return;
  }

  if (!dns_keynode_managed(keynode)) {
    return;
  }

  /*
   * If the keynode has no trust anchor set, return.
   */
  if (!dns_keynode_dsset(keynode, NULL)) {
    return;
  }

  /*
   * Check whether there's already a KEYDATA entry for this name;
   * if so, we don't need to add another.
   */
  dns_fixedname_init(&fname);
  result = dns_db_find(db, keyname, ver, dns_rdatatype_keydata,
           DNS_DBFIND_NOWILD, 0, dns_name(&fname), NULL,
           NULL);
  if (result == ISC_R_SUCCESS) {
    return;
  }

  /*
   * Create the keydata.
   */
  result = create_keydata(zone, db, ver, diff, keynode, keyname, changed);
  if (result != ISC_R_SUCCESS && result != ISC_R_NOMORE) {
    ((struct addifmissing_arg *)arg)->result = result;
  }
}

/*
 * Synchronize the set of initializing keys found in trust-anchors {}
 * statements with the set of trust anchors found in the managed-keys.bind
 * zone.  If a domain is no longer named in trust-anchors, delete all keys
 * from that domain from the key zone.  If a domain is configured as an
 * initial-key in trust-anchors, but there are no references to it in the
 * key zone, load the key zone with the initializing key(s) for that
 * domain and schedule a key refresh. If a domain is configured as
 * an initial-ds in trust-anchors, fetch the DNSKEY RRset, load the key
 * zone with the matching key, and schedule a key refresh.
 */
static isc_result_t
sync_keyzone(dns_zone_t *zone, dns_db_t *db) {
  isc_result_t result = ISC_R_SUCCESS;
  bool changed = false;
  bool commit = false;
  dns_keynode_t *keynode = NULL;
  dns_view_t *view = zone->view;
  dns_keytable_t *sr = NULL;
  dns_dbversion_t *ver = NULL;
  dns_diff_t diff;
  dns_rriterator_t rrit;
  struct addifmissing_arg arg;

  dns_zone_log(zone, ISC_LOG_DEBUG(1), "synchronizing trusted keys");

  dns_diff_init(zone->mctx, &diff);

  CHECK(dns_view_getsecroots(view, &sr));

  result = dns_db_newversion(db, &ver);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "sync_keyzone:dns_db_newversion -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  /*
   * Walk the zone DB.  If we find any keys whose names are no longer
   * in trust-anchors, or which have been changed from initial to static,
   * (meaning they are permanent and not RFC5011-maintained), delete
   * them from the zone.  Otherwise call load_secroots(), which
   * loads keys into secroots as appropriate.
   */
  dns_rriterator_init(&rrit, db, ver, 0);
  for (result = dns_rriterator_first(&rrit); result == ISC_R_SUCCESS;
       result = dns_rriterator_nextrrset(&rrit))
  {
    dns_rdataset_t *rdataset = NULL;
    dns_rdata_keydata_t keydata;
    isc_stdtime_t now = isc_stdtime_now();
    bool load = true;
    dns_name_t *rrname = NULL;
    uint32_t ttl;

    dns_rriterator_current(&rrit, &rrname, &ttl, &rdataset, NULL);
    if (!dns_rdataset_isassociated(rdataset)) {
      dns_rriterator_destroy(&rrit);
      goto cleanup;
    }

    if (rdataset->type != dns_rdatatype_keydata) {
      continue;
    }

    /*
     * The managed-keys zone can contain a placeholder instead of
     * legitimate data, in which case we will not use it, and we
     * will try to refresh it.
     */
    DNS_RDATASET_FOREACH(rdataset) {
      isc_result_t iresult;
      dns_rdata_t rdata = DNS_RDATA_INIT;

      dns_rdataset_current(rdataset, &rdata);

      iresult = dns_rdata_tostruct(&rdata, &keydata);
      /* Do we have a valid placeholder KEYDATA record? */
      if (iresult == ISC_R_SUCCESS && keydata.flags == 0 &&
          keydata.protocol == 0 && keydata.algorithm == 0)
      {
        set_refreshkeytimer(zone, &keydata, now, true);
        load = false;
      }
    }

    /*
     * Release db wrlock to prevent LOR reports against
     * dns_keytable_forall() call below.
     */
    dns_rriterator_pause(&rrit);
    result = dns_keytable_find(sr, rrname, &keynode);
    if (result != ISC_R_SUCCESS || !dns_keynode_managed(keynode)) {
      CHECK(delete_keydata(db, ver, &diff, rrname, rdataset));
      changed = true;
    } else if (load) {
      load_secroots(zone, rrname, rdataset);
    }

    if (keynode != NULL) {
      dns_keynode_detach(&keynode);
    }
  }
  dns_rriterator_destroy(&rrit);

  /*
   * Walk secroots to find any initial keys that aren't in
   * the zone.  If we find any, add them to the zone directly.
   * If any DS-style initial keys are found, refresh the key
   * zone so that they'll be looked up.
   */
  arg.db = db;
  arg.ver = ver;
  arg.result = ISC_R_SUCCESS;
  arg.diff = &diff;
  arg.zone = zone;
  arg.changed = &changed;
  dns_keytable_forall(sr, addifmissing, &arg);
  result = arg.result;
  if (changed) {
    /* Write changes to journal file. */
    CHECK(update_soa_serial(zone, db, ver, &diff, zone->mctx,
          zone->updatemethod));
    CHECK(zone_journal(zone, &diff, NULL, "sync_keyzone"));

    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
    zone_needdump(zone, 30);
    commit = true;
  }

cleanup:
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "unable to synchronize managed keys: %s",
         isc_result_totext(result));
    isc_time_settoepoch(&zone->refreshkeytime);
  }
  if (keynode != NULL) {
    dns_keynode_detach(&keynode);
  }
  if (sr != NULL) {
    dns_keytable_detach(&sr);
  }
  if (ver != NULL) {
    dns_db_closeversion(db, &ver, commit);
  }
  dns_diff_clear(&diff);

  INSIST(ver == NULL);

  return result;
}

isc_result_t
dns_zone_synckeyzone(dns_zone_t *zone) {
  isc_result_t result;
  dns_db_t *db = NULL;

  if (zone->type != dns_zone_key) {
    return DNS_R_BADZONE;
  }

  CHECK(dns_zone_getdb(zone, &db));

  LOCK_ZONE(zone);
  result = sync_keyzone(zone, db);
  UNLOCK_ZONE(zone);

cleanup:
  if (db != NULL) {
    dns_db_detach(&db);
  }
  return result;
}

static bool
zone_unchanged(dns_db_t *db1, dns_db_t *db2, isc_mem_t *mctx) {
  isc_result_t result;
  bool answer = false;
  dns_diff_t diff;

  dns_diff_init(mctx, &diff);
  result = dns_db_diffx(&diff, db1, NULL, db2, NULL, NULL);
  if (result == ISC_R_SUCCESS && ISC_LIST_EMPTY(diff.tuples)) {
    answer = true;
  }
  dns_diff_clear(&diff);
  return answer;
}

/*
 * Compare times treating epoch as "unset".
 */
static inline bool
time_greater_equal(isc_time_t a, isc_time_t b) {
  return !isc_time_isepoch(&b) && isc_time_compare(&a, &b) >= 0;
}

static inline isc_time_t
time_min(isc_time_t a, isc_time_t b) {
  if (isc_time_isepoch(&b)) {
    return a;
  }
  return isc_time_isepoch(&a) || isc_time_compare(&b, &a) < 0 ? b : a;
}

static bool
zone_maintenance_request_pending(dns_zone_t *zone) {
  REQUIRE(LOCKED_ZONE(zone));

  return zone->iss == NULL && DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
         !ISC_LIST_EMPTY(zone->maintenance_queue);
}

static unsigned char er_ndata[] = "\001*\003_er";
static dns_name_t er = DNS_NAME_INITNONABSOLUTE(er_ndata);

static isc_result_t
check_reportchannel(dns_zone_t *zone, dns_db_t *db) {
  isc_result_t result;
  dns_rdataset_t rdataset = DNS_RDATASET_INIT;
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_fixedname_t fixed;
  dns_name_t *name = NULL;

  /*
   * If this zone isn't logging reports, it's fine.
   */
  if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_LOGREPORTS)) {
    return ISC_R_SUCCESS;
  }

  /*
   * Otherwise, we need a '*._er' wildcard with a TXT rdataset.
   */
  name = dns_fixedname_initname(&fixed);
  CHECK(dns_name_concatenate(&er, &zone->origin, name));
  CHECK(dns_db_findnode(db, name, false, &node));

  dns_db_currentversion(db, &version);

  result = dns_db_findrdataset(db, node, version, dns_rdatatype_txt,
             dns_rdatatype_none, 0, &rdataset, NULL);
  dns_db_closeversion(db, &version, false);
  dns_db_detachnode(&node);
  if (result == ISC_R_SUCCESS) {
    dns_rdataset_disassociate(&rdataset);
  }

cleanup:
  return result;
}

/*
 * The zone is presumed to be locked.
 * If this is a inline_raw zone the secure version is also locked.
 */
static isc_result_t
zone_postload(dns_zone_t *zone, dns_db_t *db, isc_time_t loadtime,
        isc_result_t result) {
  unsigned int soacount = 0;
  unsigned int nscount = 0;
  unsigned int errors = 0;
  uint32_t serial, oldserial, refresh, retry, expire, minimum, soattl;
  isc_time_t now;
  bool needdump = false;
  bool fixjournal = false;
  bool hasinclude = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_HASINCLUDE);
  bool noprimary = false;
  bool had_db = false;
  bool is_dynamic = false;

  INSIST(LOCKED_ZONE(zone));
  if (dns__zone_inline_raw(zone)) {
    INSIST(LOCKED_ZONE(zone->secure));
  }

  now = isc_time_now();

  /*
   * Initiate zone transfer?  We may need a error code that
   * indicates that the "permanent" form does not exist.
   * XXX better error feedback to log.
   */
  if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) {
    if (zone->type == dns_zone_secondary ||
        zone->type == dns_zone_mirror ||
        zone->type == dns_zone_stub ||
        (zone->type == dns_zone_redirect &&
         dns_remote_addresses(&zone->primaries) == NULL))
    {
      if (result == ISC_R_FILENOTFOUND) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_DEBUG(1),
                "no master file");
      } else if (result != DNS_R_NOMASTERFILE) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_ERROR,
                "loading from master file %s "
                "failed: %s",
                zone->masterfile,
                isc_result_totext(result));
      }
    } else if (zone->type == dns_zone_primary &&
         dns__zone_inline_secure(zone) &&
         result == ISC_R_FILENOTFOUND)
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_DEBUG(1),
              "no master file; secure db will be "
              "bootstrapped from raw zone");
    } else {
      int level = ISC_LOG_ERROR;
      if (zone->type == dns_zone_key &&
          result == ISC_R_FILENOTFOUND)
      {
        level = ISC_LOG_DEBUG(1);
      }
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, level,
              "loading from master file %s failed: %s",
              zone->masterfile,
              isc_result_totext(result));
      noprimary = true;
    }

    if (zone->type != dns_zone_key) {
      goto cleanup;
    }
  }

  dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_DEBUG(2),
          "number of nodes in database: %u", dns_db_nodecount(db));

  if (result == DNS_R_SEENINCLUDE) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HASINCLUDE);
  } else {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_HASINCLUDE);
  }

  /*
   * If there's no master file for a key zone, then the zone is new:
   * create an SOA record.  (We do this now, instead of later, so that
   * if there happens to be a journal file, we can roll forward from
   * a sane starting point.)
   */
  if (noprimary && zone->type == dns_zone_key) {
    CHECK(add_soa(zone, db));
  }

  /*
   * Apply update log, if any, on initial load.
   */
  if (zone->journal != NULL &&
      !DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NOMERGE) &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
  {
    CHECK(zone_journal_rollforward(zone, db, &needdump,
                 &fixjournal));
  }

  /*
   * Obtain ns, soa and cname counts for top of zone.
   */
  INSIST(db != NULL);
  result = zone_get_from_db(zone, db, &nscount, &soacount, &soattl,
          &serial, &refresh, &retry, &expire, &minimum,
          &errors);
  if (result != ISC_R_SUCCESS && zone->type != dns_zone_key) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_ERROR,
            "could not find NS and/or SOA records");
  }

  is_dynamic = dns_zone_isdynamic(zone, true);

  /*
   * Check to make sure the journal is up to date, and remove the
   * journal file if it isn't, as we wouldn't be able to apply
   * updates otherwise.
   */
  if (zone->journal != NULL && is_dynamic &&
      !DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IXFRFROMDIFFS))
  {
    uint32_t jserial;
    dns_journal_t *journal = NULL;
    bool empty = false;

    result = dns_journal_open(zone->mctx, zone->journal,
            DNS_JOURNAL_READ, &journal);
    if (result == ISC_R_SUCCESS) {
      jserial = dns_journal_last_serial(journal);
      empty = dns_journal_empty(journal);
      dns_journal_destroy(&journal);
    } else {
      jserial = serial;
    }

    if (jserial != serial) {
      if (!empty) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_INFO,
                "journal file is out of date: "
                "removing journal file");
      }
      if (remove(zone->journal) < 0 && errno != ENOENT) {
        char strbuf[ISC_STRERRORSIZE];
        strerror_r(errno, strbuf, sizeof(strbuf));
        isc_log_write(DNS_LOGCATEGORY_GENERAL,
                DNS_LOGMODULE_ZONE,
                ISC_LOG_WARNING,
                "unable to remove journal "
                "'%s': '%s'",
                zone->journal, strbuf);
      }
    }
  }

  dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_DEBUG(1),
          "loaded; checking validity");

  /*
   * Primary / Secondary / Mirror / Stub zones require both NS and SOA
   * records at the top of the zone.
   */

  switch (zone->type) {
  case dns_zone_dlz:
  case dns_zone_primary:
  case dns_zone_secondary:
  case dns_zone_mirror:
  case dns_zone_stub:
  case dns_zone_redirect:
    if (soacount != 1) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_ERROR, "has %d SOA records",
              soacount);
      RETERR(DNS_R_BADZONE);
    }
    if (nscount == 0 && DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNS))
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_WARNING, "has no NS records");
      if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FATALNS)) {
        RETERR(DNS_R_BADZONE);
      }
    }
    if (zone->type == dns_zone_primary && errors != 0) {
      CLEANUP(DNS_R_BADZONE);
    }
    if (zone->type != dns_zone_stub &&
        zone->type != dns_zone_redirect)
    {
      CHECK(check_nsec3param(zone, db));
    }
    if (zone->type == dns_zone_primary &&
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKINTEGRITY) &&
        !integrity_checks(zone, db))
    {
      CLEANUP(DNS_R_BADZONE);
    }
    if (zone->type == dns_zone_primary &&
        DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKDUPRR) &&
        !zone_check_dup(zone, db))
    {
      CLEANUP(DNS_R_BADZONE);
    }

    if (zone->type == dns_zone_primary) {
      result = dns_zone_cdscheck(zone, db, NULL);
      if (result != ISC_R_SUCCESS) {
        dns_zone_log(zone, ISC_LOG_ERROR,
               "CDS/CDNSKEY consistency checks "
               "failed");
        goto cleanup;
      }
    }

    result = check_reportchannel(zone, db);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "'log-report-channel' is set, but no "
             "'*._er/TXT' wildcard found");
      CLEANUP(DNS_R_BADZONE);
    }

    if (zone->type == dns_zone_mirror) {
      CHECK(dns_zone_verifydb(zone->view, db, NULL));
    }

    if (zone->db != NULL) {
      unsigned int oldsoacount;

      /*
       * This is checked in zone_replacedb() for
       * secondary zones as they don't reload from disk.
       */
      result = zone_get_from_db(
        zone, zone->db, NULL, &oldsoacount, NULL,
        &oldserial, NULL, NULL, NULL, NULL, NULL);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      RUNTIME_CHECK(oldsoacount > 0U);
      if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IXFRFROMDIFFS) &&
          !isc_serial_gt(serial, oldserial))
      {
        uint32_t serialmin, serialmax;

        INSIST(zone->type == dns_zone_primary);
        INSIST(zone->raw == NULL);

        if (serial == oldserial &&
            zone_unchanged(zone->db, db, zone->mctx))
        {
          dns_zone_logc(zone,
                  DNS_LOGCATEGORY_ZONELOAD,
                  ISC_LOG_INFO,
                  "ixfr-from-differences: "
                  "unchanged");
          zone->loadtime = loadtime;
          goto done;
        }

        serialmin = (oldserial + 1) & 0xffffffffU;
        serialmax = (oldserial + 0x7fffffffU) &
              0xffffffffU;
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_ERROR,
                "ixfr-from-differences: "
                "new serial (%u) out of range "
                "[%u - %u]",
                serial, serialmin, serialmax);
        CLEANUP(DNS_R_BADZONE);
      } else if (!isc_serial_ge(serial, oldserial)) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_ERROR,
                "zone serial (%u/%u) has gone "
                "backwards",
                serial, oldserial);
      } else if (serial == oldserial && !hasinclude &&
           strcmp(zone->db_argv[0], "_builtin") != 0)
      {
        dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
                ISC_LOG_ERROR,
                "zone serial (%u) unchanged. "
                "zone may fail to transfer "
                "to secondaries.",
                serial);
      }
    }

    if (zone->type == dns_zone_primary &&
        (zone->update_acl != NULL || zone->ssutable != NULL) &&
        dns_zone_getsigresigninginterval(zone) < (3 * refresh) &&
        dns_db_issecure(db))
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_WARNING,
              "sig-re-signing-interval less than "
              "3 * refresh.");
    }

    zone->refresh = RANGE(refresh, zone->minrefresh,
              zone->maxrefresh);
    zone->retry = RANGE(retry, zone->minretry, zone->maxretry);
    zone->expire = RANGE(expire, zone->refresh + zone->retry,
             DNS_MAX_EXPIRE);
    zone->soattl = soattl;
    zone->minimum = minimum;
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HAVETIMERS);

    if (zone->type == dns_zone_secondary ||
        zone->type == dns_zone_mirror ||
        zone->type == dns_zone_stub ||
        (zone->type == dns_zone_redirect &&
         dns_remote_addresses(&zone->primaries) != NULL))
    {
      isc_time_t t;
      uint32_t delay;

      result = isc_file_getmodtime(zone->journal, &t);
      if (result != ISC_R_SUCCESS) {
        result = isc_file_getmodtime(zone->masterfile,
                   &t);
      }
      if (result == ISC_R_SUCCESS) {
        DNS_ZONE_TIME_ADD(&t, zone->expire,
              &zone->expiretime);
      } else {
        DNS_ZONE_TIME_ADD(&now, zone->retry,
              &zone->expiretime);
      }

      delay = (zone->retry -
         isc_random_uniform((zone->retry * 3) / 4));
      DNS_ZONE_TIME_ADD(&now, delay, &zone->refreshtime);
      if (isc_time_compare(&zone->refreshtime,
               &zone->expiretime) >= 0)
      {
        DNS_ZONE_SETFLAG(zone,
             DNS_ZONEFLG_FIRSTREFRESH);
        zone->refreshtime = now;
      } else {
        /* The zone is up to date. */
        DNS_ZONE_CLRFLAG(zone,
             DNS_ZONEFLG_FIRSTREFRESH);
      }
    }

    break;

  case dns_zone_key:
    /* Nothing needs to be done now */
    break;

  default:
    UNEXPECTED_ERROR("unexpected zone type %d", zone->type);
    CLEANUP(ISC_R_UNEXPECTED);
  }

  /*
   * Check for weak DNSKEY's.
   */
  if (zone->type == dns_zone_primary) {
    zone_check_dnskeys(zone, db);
  }

  /*
   * Schedule DNSSEC key refresh.
   */
  if (zone->type == dns_zone_primary && zone->kasp != NULL) {
    zone->refreshkeytime = now;
  }

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
  if (zone->db != NULL) {
    had_db = true;
    result = zone_replacedb(zone, db, false);
    ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
    if (result != ISC_R_SUCCESS) {
      goto cleanup;
    }
  } else {
    zone_attachdb(zone, db);
    ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED |
                 DNS_ZONEFLG_NEEDSTARTUPNOTIFY);
    if (dns__zone_inline_raw(zone)) {
      zone_schedule_inline_sync(zone->secure,
              inline_sync_incremental);
    }
  }

  result = ISC_R_SUCCESS;

  if (fixjournal) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FIXJOURNAL);
    zone_journal_compact(zone, zone->db, 0);
  }
  if (needdump) {
    if (zone->type == dns_zone_key) {
      zone_needdump(zone, 30);
    } else {
      zone_needdump(zone, DNS_DUMP_DELAY);
    }
  }

  if (zone->loop != NULL) {
    if (zone->type == dns_zone_primary) {
      dns__zone_set_resigntime(zone);
      resume_signingwithkey(zone);
      resume_addnsec3chain(zone);
    }

    is_dynamic = dns_zone_isdynamic(zone, false);
    if (zone->type == dns_zone_primary && is_dynamic &&
        dns_db_issecure(db) && !dns__zone_inline_raw(zone))
    {
      isc_stdtime_t resign;
      dns_name_t *name;
      dns_fixedname_t fixed;
      dns_typepair_t typepair;

      name = dns_fixedname_initname(&fixed);

      result = dns_db_getsigningtime(db, &resign, name,
                   &typepair);
      if (result == ISC_R_SUCCESS) {
        isc_stdtime_t timenow = isc_stdtime_now();
        char namebuf[DNS_NAME_FORMATSIZE];
        char typebuf[DNS_RDATATYPE_FORMATSIZE];

        dns_name_format(name, namebuf, sizeof(namebuf));
        dns_rdatatype_format(
          DNS_TYPEPAIR_COVERS(typepair), typebuf,
          sizeof(typebuf));
        dnssec_log(
          zone, ISC_LOG_DEBUG(3),
          "next resign: %s/%s "
          "in %d seconds",
          namebuf, typebuf,
          resign - timenow -
            dns_zone_getsigresigninginterval(
              zone));
      } else {
        dnssec_log(zone, ISC_LOG_WARNING,
             "signed dynamic zone has no "
             "resign event scheduled");
      }
    }

    dns__zone_settimer(zone, now);
  }

  /*
   * Clear old include list.
   */
  ISC_LIST_FOREACH(zone->includes, inc, link) {
    ISC_LIST_UNLINK(zone->includes, inc, link);
    isc_mem_free(zone->mctx, inc->name);
    isc_mem_put(zone->mctx, inc, sizeof(*inc));
  }

  /*
   * Transfer new include list.
   */
  ISC_LIST_FOREACH(zone->newincludes, inc, link) {
    ISC_LIST_UNLINK(zone->newincludes, inc, link);
    ISC_LIST_APPEND(zone->includes, inc, link);
  }

  if (!dns_db_ispersistent(db)) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_INFO,
            "loaded serial %u%s", serial,
            dns_db_issecure(db) ? " (DNSSEC signed)" : "");
  }

  if (!had_db && zone->type == dns_zone_mirror) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_INFO,
            "mirror zone is now in use");
  }

  zone->loadtime = loadtime;
  goto done;

cleanup:
  if (result != ISC_R_SUCCESS) {
    dns_zone_rpz_disable_db(zone, db);
    dns_zone_catz_disable_db(zone, db);
  }

  ISC_LIST_FOREACH(zone->newincludes, inc, link) {
    ISC_LIST_UNLINK(zone->newincludes, inc, link);
    isc_mem_free(zone->mctx, inc->name);
    isc_mem_put(zone->mctx, inc, sizeof(*inc));
  }
  if (zone->type == dns_zone_secondary || zone->type == dns_zone_mirror ||
      zone->type == dns_zone_stub || zone->type == dns_zone_key ||
      (zone->type == dns_zone_redirect &&
       dns_remote_addresses(&zone->primaries) != NULL))
  {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FIRSTREFRESH);

    if (zone->journal != NULL) {
      zone_saveunique(zone, zone->journal, "jn-XXXXXXXX");
    }
    if (zone->masterfile != NULL) {
      zone_saveunique(zone, zone->masterfile, "db-XXXXXXXX");
    }

    /* Mark the zone for immediate refresh. */
    zone->refreshtime = now;
    if (zone->loop != NULL) {
      dns__zone_settimer(zone, now);
    }
    result = ISC_R_SUCCESS;
  } else if (zone->type == dns_zone_primary ||
       zone->type == dns_zone_redirect)
  {
    if (!(dns__zone_inline_secure(zone) &&
          result == ISC_R_FILENOTFOUND))
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_ERROR,
              "not loaded due to errors.");
    } else if (zone->type == dns_zone_primary) {
      result = ISC_R_SUCCESS;
    }
  }

done:
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_LOADPENDING);
  /*
   * If this is an inline-signed zone and we were called for the raw
   * zone, we need to clear DNS_ZONEFLG_LOADPENDING for the secure zone
   * as well, but only if this is a reload, not an initial zone load: in
   * the former case, zone_postload() will not be run for the secure
   * zone; in the latter case, it will be.  Check which case we are
   * dealing with by consulting the DNS_ZONEFLG_LOADED flag for the
   * secure zone: if it is set, this must be a reload.
   */
  if (dns__zone_inline_raw(zone) &&
      DNS_ZONE_FLAG(zone->secure, DNS_ZONEFLG_LOADED))
  {
    DNS_ZONE_CLRFLAG(zone->secure, DNS_ZONEFLG_LOADPENDING);
    /*
     * Re-start zone maintenance if it had been stalled
     * due to DNS_ZONEFLG_LOADPENDING being set when
     * zone_maintenance was called.
     */
    if (zone->secure->loop != NULL) {
      dns__zone_settimer(zone->secure, now);
    }
  }

  zone_debuglog(zone, __func__, 99, "done");

  return result;
}

bool
dns__zone_free_check(dns_zone_t *zone) {
  REQUIRE(LOCKED_ZONE(zone));

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SHUTDOWN) &&
      isc_refcount_current(&zone->irefs) == 0)
  {
    /*
     * DNS_ZONEFLG_SHUTDOWN can only be set if references == 0.
     */
    INSIST(isc_refcount_current(&zone->references) == 0);
    return true;
  }
  return false;
}

void
dns_zone_forcemaint(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  LOCK_ZONE(zone);
  dns__zone_settimer(zone, isc_time_now());
  UNLOCK_ZONE(zone);
}

unsigned int
dns_zone_getcount(dns_zone_t *zone, dns_zonestate_t state) {
  unsigned int count = 0;
  REQUIRE(DNS_ZONE_VALID(zone));
  LOCK_ZONE(zone);
  switch (state) {
  case DNS_ZONESTATE_XFERFIRSTREFRESH:
    count = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FIRSTREFRESH);
    break;
  case DNS_ZONESTATE_SOAQUERY:
    count = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH);
    break;
  case DNS_ZONESTATE_ANY:
  case DNS_ZONESTATE_AUTOMATIC:
    if (zone->view == NULL ||
        strcmp(zone->view->name, "_bind") != 0)
    {
      count = state == DNS_ZONESTATE_ANY || zone->automatic;
    }
    break;
  default:
    UNREACHABLE();
  }
  UNLOCK_ZONE(zone);
  return count;
}

static bool
zone_check_ns(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version,
        dns_name_t *name, bool logit) {
  isc_result_t result;
  char namebuf[DNS_NAME_FORMATSIZE];
  char altbuf[DNS_NAME_FORMATSIZE];
  dns_fixedname_t fixed;
  dns_name_t *foundname;
  int level;

  if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNS)) {
    return true;
  }

  if (zone->type == dns_zone_primary) {
    level = ISC_LOG_ERROR;
  } else {
    level = ISC_LOG_WARNING;
  }

  foundname = dns_fixedname_initname(&fixed);

  result = dns_db_find(db, name, version, dns_rdatatype_a, 0, 0,
           foundname, NULL, NULL);
  if (result == ISC_R_SUCCESS) {
    return true;
  }

  if (result == DNS_R_NXRRSET) {
    result = dns_db_find(db, name, version, dns_rdatatype_aaaa, 0,
             0, foundname, NULL, NULL);
    if (result == ISC_R_SUCCESS) {
      return true;
    }
  }

  if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
      result == DNS_R_EMPTYNAME)
  {
    if (logit) {
      dns_name_format(name, namebuf, sizeof namebuf);
      dns_zone_log(zone, level,
             "NS '%s' has no address "
             "records (A or AAAA)",
             namebuf);
    }
    return false;
  }

  if (result == DNS_R_CNAME) {
    if (logit) {
      dns_name_format(name, namebuf, sizeof namebuf);
      dns_zone_log(zone, level,
             "NS '%s' is a CNAME "
             "(illegal)",
             namebuf);
    }
    return false;
  }

  if (result == DNS_R_DNAME) {
    if (logit) {
      dns_name_format(name, namebuf, sizeof namebuf);
      dns_name_format(foundname, altbuf, sizeof altbuf);
      dns_zone_log(zone, level,
             "NS '%s' is below a DNAME "
             "'%s' (illegal)",
             namebuf, altbuf);
    }
    return false;
  }

  return true;
}

static isc_result_t
zone_count_ns_rr(dns_zone_t *zone, dns_db_t *db, dns_dbnode_t *node,
     dns_dbversion_t *version, unsigned int *nscount,
     unsigned int *errors, bool logit) {
  isc_result_t result;
  unsigned int count = 0;
  unsigned int ecount = 0;
  dns_rdataset_t rdataset;
  dns_rdata_ns_t ns;

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, version, dns_rdatatype_ns,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto success;
  }
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto invalidate_rdataset;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    if (errors != NULL && zone->rdclass == dns_rdataclass_in &&
        (zone->type == dns_zone_primary ||
         zone->type == dns_zone_secondary ||
         zone->type == dns_zone_mirror))
    {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&rdataset, &rdata);

      result = dns_rdata_tostruct(&rdata, &ns);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (dns_name_issubdomain(&ns.name, &zone->origin) &&
          !zone_check_ns(zone, db, version, &ns.name, logit))
      {
        ecount++;
      }
    }
    count++;
  }
  dns_rdataset_disassociate(&rdataset);

success:
  SET_IF_NOT_NULL(nscount, count);
  SET_IF_NOT_NULL(errors, ecount);

  result = ISC_R_SUCCESS;

invalidate_rdataset:
  dns_rdataset_invalidate(&rdataset);

  return result;
}

#define SET_SOA_VALUES(soattl_v, serial_v, refresh_v, retry_v, expire_v, \
           minimum_v)                                        \
  {                                                                \
    SET_IF_NOT_NULL(soattl, soattl_v);                       \
    SET_IF_NOT_NULL(serial, serial_v);                       \
    SET_IF_NOT_NULL(refresh, refresh_v);                     \
    SET_IF_NOT_NULL(retry, retry_v);                         \
    SET_IF_NOT_NULL(expire, expire_v);                       \
    SET_IF_NOT_NULL(minimum, minimum_v);                     \
  }

#define CLR_SOA_VALUES()                          \
  {                                         \
    SET_SOA_VALUES(0, 0, 0, 0, 0, 0); \
  }

static isc_result_t
zone_load_soa_rr(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
     unsigned int *soacount, uint32_t *soattl, uint32_t *serial,
     uint32_t *refresh, uint32_t *retry, uint32_t *expire,
     uint32_t *minimum) {
  isc_result_t result;
  unsigned int count = 0;
  dns_rdataset_t rdataset;

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, version, dns_rdatatype_soa,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    result = ISC_R_SUCCESS;
    goto invalidate_rdataset;
  }
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto invalidate_rdataset;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &rdata);

    count++;
    if (count == 1) {
      dns_rdata_soa_t soa;
      result = dns_rdata_tostruct(&rdata, &soa);
      SET_SOA_VALUES(rdataset.ttl, soa.serial, soa.refresh,
               soa.retry, soa.expire, soa.minimum);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
    }
  }
  dns_rdataset_disassociate(&rdataset);

  result = ISC_R_SUCCESS;

invalidate_rdataset:
  SET_IF_NOT_NULL(soacount, count);
  if (count == 0) {
    CLR_SOA_VALUES();
  }

  dns_rdataset_invalidate(&rdataset);

  return result;
}

/*
 * zone must be locked.
 */
static isc_result_t
zone_get_from_db(dns_zone_t *zone, dns_db_t *db, unsigned int *nscount,
     unsigned int *soacount, uint32_t *soattl, uint32_t *serial,
     uint32_t *refresh, uint32_t *retry, uint32_t *expire,
     uint32_t *minimum, unsigned int *errors) {
  isc_result_t result;
  isc_result_t answer = ISC_R_SUCCESS;
  dns_dbversion_t *version = NULL;
  dns_dbnode_t *node;

  REQUIRE(db != NULL);
  REQUIRE(zone != NULL);

  dns_db_currentversion(db, &version);

  SET_IF_NOT_NULL(nscount, 0);
  SET_IF_NOT_NULL(soacount, 0);
  SET_IF_NOT_NULL(errors, 0);
  CLR_SOA_VALUES();

  node = NULL;
  result = dns_db_findnode(db, &zone->origin, false, &node);
  if (result != ISC_R_SUCCESS) {
    answer = result;
    goto closeversion;
  }

  if (nscount != NULL || errors != NULL) {
    result = zone_count_ns_rr(zone, db, node, version, nscount,
            errors, true);
    if (result != ISC_R_SUCCESS) {
      answer = result;
    }
  }

  if (soacount != NULL || soattl != NULL || serial != NULL ||
      refresh != NULL || retry != NULL || expire != NULL ||
      minimum != NULL)
  {
    result = zone_load_soa_rr(db, node, version, soacount, soattl,
            serial, refresh, retry, expire,
            minimum);
    if (result != ISC_R_SUCCESS) {
      answer = result;
    }
  }

  dns_db_detachnode(&node);
closeversion:
  dns_db_closeversion(db, &version, false);

  return answer;
}

static void
zone_destroy(dns_zone_t *zone) {
  /*
   * Stop things being restarted after we cancel them below.
   */
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXITING);
  dns_zone_log(zone, ISC_LOG_DEBUG(1), "final reference detached");

  if (zone->loop == NULL) {
    /*
     * This zone is unmanaged; we're probably running in
     * named-checkzone or a unit test. There's no loop, so we
     * need to free it immediately.
     */
    zone_shutdown(zone);
  } else {
    /*
     * This zone has a loop; it can clean
     * itself up asynchronously.
     */
    isc_async_run(zone->loop, zone_shutdown, zone);
  }
}

#if DNS_ZONE_TRACE
ISC_REFCOUNT_TRACE_IMPL(dns_zone, zone_destroy);
#else
ISC_REFCOUNT_IMPL(dns_zone, zone_destroy);
#endif

static void
zone_iattach(dns_zone_t *source, dns_zone_t **target) {
  REQUIRE(DNS_ZONE_VALID(source));
  REQUIRE(LOCKED_ZONE(source));
  REQUIRE(target != NULL && *target == NULL);
  INSIST(isc_refcount_increment0(&source->irefs) +
           isc_refcount_current(&source->references) >
         0);
  *target = source;
}

void
dns__zone_iattach_locked(dns_zone_t *source, dns_zone_t **target) {
  zone_iattach(source, target);
}

void
dns_zone_iattach(dns_zone_t *source, dns_zone_t **target) {
  REQUIRE(DNS_ZONE_VALID(source));

  LOCK_ZONE(source);
  zone_iattach(source, target);
  UNLOCK_ZONE(source);
}

static void
zone_idetach(dns_zone_t **zonep) {
  dns_zone_t *zone;

  /*
   * 'zone' locked by caller.
   */
  REQUIRE(zonep != NULL && DNS_ZONE_VALID(*zonep));
  REQUIRE(LOCKED_ZONE(*zonep));

  zone = *zonep;
  *zonep = NULL;

  INSIST(isc_refcount_decrement(&zone->irefs) - 1 +
           isc_refcount_current(&zone->references) >
         0);
}

void
dns__zone_idetach_locked(dns_zone_t **zonep) {
  zone_idetach(zonep);
}

void
dns_zone_idetach(dns_zone_t **zonep) {
  dns_zone_t *zone;

  REQUIRE(zonep != NULL && DNS_ZONE_VALID(*zonep));

  zone = *zonep;
  *zonep = NULL;

  if (isc_refcount_decrement(&zone->irefs) == 1) {
    bool free_needed;
    LOCK_ZONE(zone);
    free_needed = dns__zone_free_check(zone);
    UNLOCK_ZONE(zone);
    if (free_needed) {
      dns__zone_free(zone);
    }
  }
}

isc_refcount_t *
dns__zone_irefs(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return &zone->irefs;
}

static void
dns_zone_setskr(dns_zone_t *zone, dns_skr_t *skr) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  zone->skrbundle = NULL;
  if (zone->skr != NULL) {
    dns_skr_detach(&zone->skr);
  }
  if (skr != NULL) {
    dns_skr_attach(skr, &zone->skr);
  }
  UNLOCK_ZONE(zone);
}

dns_skrbundle_t *
dns_zone_getskrbundle(dns_zone_t *zone) {
  dns_skrbundle_t *bundle;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  if (dns__zone_inline_raw(zone) && zone->secure != NULL) {
    bundle = zone->secure->skrbundle;
  } else {
    bundle = zone->skrbundle;
  }
  UNLOCK_ZONE(zone);

  return bundle;
}

void
dns_zone_setoption(dns_zone_t *zone, dns_zoneopt_t option, bool value) {
  REQUIRE(DNS_ZONE_VALID(zone));

  if (value) {
    DNS_ZONE_SETOPTION(zone, option);
  } else {
    DNS_ZONE_CLROPTION(zone, option);
  }
}

dns_zoneopt_t
dns_zone_getoptions(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return atomic_load_relaxed(&zone->options);
}

static bool
was_dumping(dns_zone_t *zone) {
  REQUIRE(LOCKED_ZONE(zone));

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
    return true;
  }

  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DUMPING);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
  isc_time_settoepoch(&zone->dumptime);
  return false;
}

/*
 * Key files are named after the key tag, but distinct keys may share a key
 * tag, e.g. an offline KSK and a ZSK.  Treat a key file holding a different
 * key than 'pubkey' as missing.
 */
static isc_result_t
keyfromdir(dst_key_t *pubkey, const char *directory, isc_mem_t *mctx,
     dst_key_t **key) {
  isc_result_t result;

  result = dst_key_fromfile(
    dst_key_name(pubkey), dst_key_id(pubkey), dst_key_alg(pubkey),
    DST_TYPE_PUBLIC | DST_TYPE_PRIVATE | DST_TYPE_STATE, directory,
    mctx, key);
  if (result == ISC_R_SUCCESS && !dst_key_pubcompare(pubkey, *key, true))
  {
    dst_key_free(key);
    result = ISC_R_FILENOTFOUND;
  }

  return result;
}

static isc_result_t
keyfromfile(dns_zone_t *zone, dst_key_t *pubkey, isc_mem_t *mctx,
      dst_key_t **key) {
  const char *directory = zone->keydirectory;
  dns_kasp_t *kasp = zone->kasp;
  dst_key_t *foundkey = NULL;
  isc_result_t result = ISC_R_NOTFOUND;

  if (kasp == NULL || (strcmp(dns_kasp_getname(kasp), "none") == 0) ||
      (strcmp(dns_kasp_getname(kasp), "insecure") == 0))
  {
    result = keyfromdir(pubkey, directory, mctx, &foundkey);
  } else {
    ISC_LIST_FOREACH(dns_kasp_keys(kasp), kkey, link) {
      dns_keystore_t *ks = dns_kasp_key_keystore(kkey);
      directory = dns_keystore_directory(ks,
                 zone->keydirectory);

      result = keyfromdir(pubkey, directory, mctx, &foundkey);
      if (result == ISC_R_SUCCESS) {
        break;
      }
    }
  }

  *key = foundkey;
  return result;
}

static isc_result_t
findzonekeys(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
       dns_dbnode_t *node, const dns_name_t *name, isc_stdtime_t now,
       isc_mem_t *mctx, unsigned int maxkeys, dst_key_t **keys,
       unsigned int *nkeys) {
  dns_rdataset_t rdataset;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  isc_result_t result;
  dst_key_t *pubkey = NULL;
  unsigned int count = 0;

  *nkeys = 0;
  memset(keys, 0, sizeof(*keys) * maxkeys);
  dns_rdataset_init(&rdataset);
  CHECK(dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey, 0, 0,
          &rdataset, NULL));
  CHECK(dns_rdataset_first(&rdataset));
  while (result == ISC_R_SUCCESS && count < maxkeys) {
    pubkey = NULL;
    dns_rdataset_current(&rdataset, &rdata);

    result = dns_dnssec_keyfromrdata(name, &rdata, mctx, &pubkey);
    if (result != ISC_R_SUCCESS) {
      goto next;
    }
    dst_key_setttl(pubkey, rdataset.ttl);

    if (!ZONEKEY(pubkey)) {
      goto next;
    }
    /* Corrupted .key file? */
    if (!dns_name_equal(name, dst_key_name(pubkey))) {
      goto next;
    }
    keys[count] = NULL;
    result = keyfromfile(zone, pubkey, mctx, &keys[count]);

    /*
     * If the key was revoked and the private file
     * doesn't exist, maybe it was revoked internally
     * by named.  Try loading the unrevoked version.
     */
    if (result == ISC_R_FILENOTFOUND) {
      uint32_t flags;
      flags = dst_key_flags(pubkey);
      if ((flags & DNS_KEYFLAG_REVOKE) != 0) {
        dst_key_setflags(pubkey,
             flags & ~DNS_KEYFLAG_REVOKE);
        result = keyfromfile(zone, pubkey, mctx,
                 &keys[count]);
        if (result == ISC_R_SUCCESS &&
            dst_key_pubcompare(pubkey, keys[count],
                   false))
        {
          dst_key_setflags(keys[count], flags);
        }
        dst_key_setflags(pubkey, flags);
      }
    }

    if (result != ISC_R_SUCCESS) {
      char filename[DNS_NAME_FORMATSIZE + DST_ALG_FORMATSIZE +
              sizeof("key file for //65535")];
      isc_result_t result2;
      isc_buffer_t buf;

      isc_buffer_init(&buf, filename, sizeof(filename));
      result2 = dst_key_getfilename(
        dst_key_name(pubkey), dst_key_id(pubkey),
        dst_key_alg(pubkey),
        DST_TYPE_PUBLIC | DST_TYPE_PRIVATE |
          DST_TYPE_STATE,
        NULL, mctx, &buf);
      if (result2 != ISC_R_SUCCESS) {
        char namebuf[DNS_NAME_FORMATSIZE];
        char algbuf[DST_ALG_FORMATSIZE];

        dns_name_format(dst_key_name(pubkey), namebuf,
            sizeof(namebuf));
        dst_algorithm_format(dst_key_alg(pubkey),
                 algbuf, sizeof(algbuf));
        snprintf(filename, sizeof(filename) - 1,
           "key file for %s/%s/%hu", namebuf,
           algbuf, dst_key_id(pubkey));
      }

      isc_log_write(DNS_LOGCATEGORY_GENERAL,
              DNS_LOGMODULE_DNSSEC, ISC_LOG_WARNING,
              "dns_zone_findkeys: error reading %s: %s",
              filename, isc_result_totext(result));
    }

    if (result == ISC_R_FILENOTFOUND || result == ISC_R_NOPERM) {
      keys[count] = pubkey;
      pubkey = NULL;
      count++;
      goto next;
    }

    CHECK(result);

    /*
     * If a key is marked inactive, skip it
     */
    if (!dns_dnssec_keyactive(keys[count], now)) {
      dst_key_setinactive(pubkey, true);
      dst_key_free(&keys[count]);
      keys[count] = pubkey;
      pubkey = NULL;
      count++;
      goto next;
    }

    /*
     * Whatever the key's default TTL may have
     * been, the rdataset TTL takes priority.
     */
    dst_key_setttl(keys[count], rdataset.ttl);
    count++;
  next:
    if (pubkey != NULL) {
      dst_key_free(&pubkey);
    }
    dns_rdata_reset(&rdata);
    result = dns_rdataset_next(&rdataset);
  }
  if (result != ISC_R_NOMORE) {
    CHECK(result);
  }
  if (count == 0) {
    result = ISC_R_NOTFOUND;
  } else {
    result = ISC_R_SUCCESS;
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  if (pubkey != NULL) {
    dst_key_free(&pubkey);
  }
  if (result != ISC_R_SUCCESS) {
    while (count > 0) {
      dst_key_free(&keys[--count]);
    }
  }
  *nkeys = count;
  return result;
}

/*%
 * Find up to 'maxkeys' DNSSEC keys used for signing version 'ver' of database
 * 'db' for zone 'zone' in its key directory, then load these keys into 'keys'.
 * Only load the public part of a given key if it is not active at timestamp
 * 'now'.  Store the number of keys found in 'nkeys'.
 */
isc_result_t
dns_zone_findkeys(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
      isc_stdtime_t now, isc_mem_t *mctx, unsigned int maxkeys,
      dst_key_t **keys, unsigned int *nkeys) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(mctx != NULL);
  REQUIRE(nkeys != NULL);
  REQUIRE(keys != NULL);

  CHECK(dns_db_findnode(db, dns_db_origin(db), false, &node));

  dns_zone_lock_keyfiles(zone);

  result = findzonekeys(zone, db, ver, node, dns_db_origin(db), now, mctx,
            maxkeys, keys, nkeys);

  dns_zone_unlock_keyfiles(zone);

  if (result == ISC_R_NOTFOUND) {
    result = ISC_R_SUCCESS;
  }

cleanup:

  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

void
dns_zone_prepare_shutdown(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXITING);
  UNLOCK_ZONE(zone);
}

/*%
 * Find DNSSEC keys used for signing zone with dnssec-policy. Load these keys
 * into 'keys'. Requires KASP to be locked.
 */
isc_result_t
dns_zone_getdnsseckeys(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
           isc_stdtime_t now, dns_dnsseckeylist_t *keys) {
  isc_result_t result;
  const char *dir = dns_zone_getkeydirectory(zone);
  dns_dbnode_t *node = NULL;
  dns_dnsseckeylist_t dnskeys;
  dns_name_t *origin = dns_zone_getorigin(zone);
  dns_kasp_t *kasp = zone->kasp;
  dns_rdataset_t keyset;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(kasp != NULL);

  ISC_LIST_INIT(dnskeys);

  dns_rdataset_init(&keyset);

  CHECK(dns_db_findnode(db, origin, false, &node));

  /* Get keys from private key files. */
  dns_zone_lock_keyfiles(zone);
  result = dns_dnssec_findmatchingkeys(
    origin, kasp, dir, dns_zone_getkeystores(zone), now, false,
    dns_zone_getmctx(zone), keys);
  dns_zone_unlock_keyfiles(zone);

  if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  /* Get public keys (dnskeys). */
  dns_rdataset_init(&keyset);
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey,
             dns_rdatatype_none, 0, &keyset, NULL);
  if (result == ISC_R_SUCCESS) {
    CHECK(dns_dnssec_keylistfromrdataset(
      origin, kasp, dir, dns_zone_getmctx(zone), &keyset,
      NULL, NULL, false, false, &dnskeys));
  } else if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  /* Add new 'dnskeys' to 'keys'. */
  ISC_LIST_FOREACH(dnskeys, k1, link) {
    bool match = false;

    ISC_LIST_FOREACH(*keys, k2, link) {
      if (dst_key_compare(k1->key, k2->key)) {
        match = true;
        break;
      }
    }

    /* No match found, add the new key. */
    if (!match) {
      ISC_LIST_UNLINK(dnskeys, k1, link);
      ISC_LIST_APPEND(*keys, k1, link);
    }
  }

cleanup:
  dns_rdataset_cleanup(&keyset);
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  ISC_LIST_FOREACH(dnskeys, key, link) {
    ISC_LIST_UNLINK(dnskeys, key, link);
    dns_dnsseckey_destroy(dns_zone_getmctx(zone), &key);
  }
  return result;
}

static isc_result_t
offline(dns_db_t *db, dns_dbversion_t *ver, dns__zonediff_t *zonediff,
  dns_name_t *name, dns_ttl_t ttl, dns_rdata_t *rdata) {
  isc_result_t result;

  if ((rdata->flags & DNS_RDATA_OFFLINE) != 0) {
    return ISC_R_SUCCESS;
  }
  RETERR(update_one_rr(db, ver, zonediff->diff, DNS_DIFFOP_DELRESIGN,
           name, ttl, rdata));
  rdata->flags |= DNS_RDATA_OFFLINE;
  result = update_one_rr(db, ver, zonediff->diff, DNS_DIFFOP_ADDRESIGN,
             name, ttl, rdata);
  zonediff->offline = true;
  return result;
}

static void
set_key_expiry_warning(dns_zone_t *zone, isc_stdtime_t when,
           isc_stdtime_t now) {
  unsigned int delta;
  char timebuf[80];

  LOCK_ZONE(zone);
  zone->key_expiry = when;
  if (when <= now) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "DNSKEY RRSIG(s) have expired");
    isc_time_settoepoch(&zone->keywarntime);
  } else if (when < now + 7 * 24 * 3600) {
    isc_time_t t;
    isc_time_set(&t, when, 0);
    isc_time_formattimestamp(&t, timebuf, 80);
    dns_zone_log(zone, ISC_LOG_WARNING,
           "DNSKEY RRSIG(s) will expire within 7 days: %s",
           timebuf);
    delta = when - now;
    delta--;      /* loop prevention */
    delta /= 24 * 3600; /* to whole days */
    delta *= 24 * 3600; /* to seconds */
    isc_time_set(&zone->keywarntime, when - delta, 0);
  } else {
    isc_time_set(&zone->keywarntime, when - 7 * 24 * 3600, 0);
    isc_time_formattimestamp(&zone->keywarntime, timebuf, 80);
    dns_zone_log(zone, ISC_LOG_NOTICE, "setting keywarntime to %s",
           timebuf);
  }
  UNLOCK_ZONE(zone);
}

/*
 * Helper function to del_sigs(). We don't want to delete RRSIGs that
 * have no new key.
 */
static bool
delsig_ok(dns_rdata_rrsig_t *rrsig_ptr, dst_key_t **keys, unsigned int nkeys,
    bool kasp, bool *warn) {
  unsigned int i = 0;
  isc_result_t ret;
  bool have_ksk = false, have_zsk = false;
  bool have_pksk = false, have_pzsk = false;
  dst_algorithm_t algorithm;

  algorithm = dst_algorithm_fromdata(
    rrsig_ptr->algorithm, rrsig_ptr->signature, rrsig_ptr->siglen);

  for (i = 0; i < nkeys; i++) {
    bool ksk, zsk;

    if (have_pksk && have_ksk && have_pzsk && have_zsk) {
      break;
    }

    if (algorithm != dst_key_alg(keys[i])) {
      continue;
    }

    ret = dst_key_getbool(keys[i], DST_BOOL_KSK, &ksk);
    if (ret != ISC_R_SUCCESS) {
      ksk = KSK(keys[i]);
    }
    ret = dst_key_getbool(keys[i], DST_BOOL_ZSK, &zsk);
    if (ret != ISC_R_SUCCESS) {
      zsk = !KSK(keys[i]);
    }

    if (ksk) {
      have_ksk = true;
      if (dst_key_isprivate(keys[i])) {
        have_pksk = true;
      }
    }
    if (zsk) {
      have_zsk = true;
      if (dst_key_isprivate(keys[i])) {
        have_pzsk = true;
      }
    }
  }

  if (have_zsk && have_ksk && !have_pzsk) {
    *warn = true;
  }

  if (have_pksk && have_pzsk) {
    return true;
  }

  /*
   * Deleting the SOA RRSIG is always okay.
   */
  if (rrsig_ptr->covered == dns_rdatatype_soa) {
    return true;
  }

  /*
   * It's okay to delete a signature if there is an active key with the
   * same algorithm to replace it, unless that violates the DNSSEC
   * policy.
   */
  if (have_pksk || have_pzsk) {
    if (kasp && have_pzsk) {
      return true;
    }
    return !kasp;
  }

  /*
   * Failing that, it is *not* okay to delete a signature
   * if the associated public key is still in the DNSKEY RRset
   */
  for (i = 0; i < nkeys; i++) {
    if ((algorithm == dst_key_alg(keys[i])) &&
        (rrsig_ptr->keyid == dst_key_id(keys[i])))
    {
      return false;
    }
  }

  /*
   * But if the key is gone, then go ahead.
   */
  return true;
}

/*
 * Delete expired RRsigs and any RRsigs we are about to re-sign.
 * See also update.c:del_keysigs().
 */
static isc_result_t
del_sigs(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
   dns_rdatatype_t type, dns__zonediff_t *zonediff, dst_key_t **keys,
   unsigned int nkeys, isc_stdtime_t now, bool incremental) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset;
  unsigned int i;
  dns_rdata_rrsig_t rrsig;
  dns_kasp_t *kasp = zone->kasp;
  bool found;
  bool offlineksk = false;
  int64_t timewarn = 0, timemaybe = 0;

  dns_rdataset_init(&rdataset);

  if (kasp != NULL) {
    offlineksk = dns_kasp_offlineksk(kasp);
  }

  if (type == dns_rdatatype_nsec3) {
    result = dns_db_findnsec3node(db, name, false, &node);
  } else {
    result = dns_db_findnode(db, name, false, &node);
  }
  if (result == ISC_R_NOTFOUND) {
    return ISC_R_SUCCESS;
  }
  CHECK(result);

  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_rrsig, type,
             (isc_stdtime_t)0, &rdataset, NULL);
  dns_db_detachnode(&node);

  if (result == ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    return ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dst_algorithm_t algorithm;

    dns_rdataset_current(&rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &rrsig);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    algorithm = dst_algorithm_fromdata(
      rrsig.algorithm, rrsig.signature, rrsig.siglen);

    if (!dns_rdatatype_iskeymaterial(type)) {
      bool warn = false, deleted = false;
      if (delsig_ok(&rrsig, keys, nkeys, kasp != NULL, &warn))
      {
        result = update_one_rr(db, ver, zonediff->diff,
                   DNS_DIFFOP_DELRESIGN,
                   name, rdataset.ttl,
                   &rdata);
        if (result != ISC_R_SUCCESS) {
          break;
        }
        deleted = true;
      }
      if (warn && !deleted) {
        /*
         * At this point, we've got an RRSIG,
         * which is signed by an inactive key.
         * An administrator needs to provide a new
         * key/alg, but until that time, we want to
         * keep the old RRSIG.  Marking the key as
         * offline will prevent us spinning waiting
         * for the private part.
         */
        if (incremental) {
          result = offline(db, ver, zonediff,
               name, rdataset.ttl,
               &rdata);
          if (result != ISC_R_SUCCESS) {
            break;
          }
        }

        /*
         * Log the key id and algorithm of
         * the inactive key with no replacement
         */
        if (zone->log_key_expired_timer <= now) {
          char origin[DNS_NAME_FORMATSIZE];
          char algbuf[DST_ALG_FORMATSIZE];
          dns_name_format(&zone->origin, origin,
              sizeof(origin));
          dst_algorithm_format(algorithm, algbuf,
                   sizeof(algbuf));
          dns_zone_log(zone, ISC_LOG_WARNING,
                 "Key %s/%s/%hu "
                 "missing or inactive "
                 "and has no replacement: "
                 "retaining signatures.",
                 origin, algbuf,
                 rrsig.keyid);
          zone->log_key_expired_timer = now +
                      3600;
        }
      }
      continue;
    }

    /*
     * KSK RRSIGs requires special processing.
     */
    found = false;
    for (i = 0; i < nkeys; i++) {
      if (algorithm == dst_key_alg(keys[i]) &&
          rrsig.keyid == dst_key_id(keys[i]))
      {
        found = true;
        /*
         * Mark offline DNSKEY.
         * We want the earliest offline expire time
         * iff there is a new offline signature.
         */
        if (!dst_key_inactive(keys[i]) &&
            !dst_key_isprivate(keys[i]) && !offlineksk)
        {
          int64_t timeexpire = dns_time64_from32(
            rrsig.timeexpire);
          if (timewarn != 0 &&
              timewarn > timeexpire)
          {
            timewarn = timeexpire;
          }
          if (rdata.flags & DNS_RDATA_OFFLINE) {
            if (timemaybe == 0 ||
                timemaybe > timeexpire)
            {
              timemaybe = timeexpire;
            }
            break;
          }
          if (timewarn == 0) {
            timewarn = timemaybe;
          }
          if (timewarn == 0 ||
              timewarn > timeexpire)
          {
            timewarn = timeexpire;
          }
          result = offline(db, ver, zonediff,
               name, rdataset.ttl,
               &rdata);
          break;
        }
        result = update_one_rr(db, ver, zonediff->diff,
                   DNS_DIFFOP_DELRESIGN,
                   name, rdataset.ttl,
                   &rdata);
        break;
      }
    }

    /*
     * If there is not a matching DNSKEY then
     * delete the RRSIG.
     */
    if (!found) {
      result = update_one_rr(db, ver, zonediff->diff,
                 DNS_DIFFOP_DELRESIGN, name,
                 rdataset.ttl, &rdata);
    }
    if (result != ISC_R_SUCCESS) {
      break;
    }
  }

  dns_rdataset_disassociate(&rdataset);
  if (timewarn > 0) {
    isc_stdtime_t stdwarn = (isc_stdtime_t)timewarn;
    if (timewarn == stdwarn) {
      set_key_expiry_warning(zone, (isc_stdtime_t)timewarn,
                 now);
    } else {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "key expiry warning time out of range");
    }
  }
cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

static isc_result_t
add_sigs(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name, dns_zone_t *zone,
   dns_rdatatype_t type, dns_diff_t *diff, dst_key_t **keys, size_t nkeys,
   isc_mem_t *mctx, isc_stdtime_t now, isc_stdtime_t inception,
   isc_stdtime_t expire) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_stats_t *dnssecsignstats;
  dns_rdataset_t rdataset;
  dns_rdata_t sig_rdata = DNS_RDATA_INIT;
  unsigned char data[DNS_RDATA_MAXLENGTH];
  isc_buffer_t buffer;
  bool use_kasp = false;
  bool offlineksk = false;

  if (zone->kasp != NULL) {
    use_kasp = true;
    offlineksk = dns_kasp_offlineksk(zone->kasp);
  }

  dns_rdataset_init(&rdataset);
  isc_buffer_init(&buffer, data, sizeof(data));

  if (type == dns_rdatatype_nsec3) {
    result = dns_db_findnsec3node(db, name, false, &node);
  } else {
    result = dns_db_findnode(db, name, false, &node);
  }
  if (result == ISC_R_NOTFOUND) {
    return ISC_R_SUCCESS;
  }
  CHECK(result);

  result = dns_db_findrdataset(db, node, ver, type, 0, (isc_stdtime_t)0,
             &rdataset, NULL);
  dns_db_detachnode(&node);
  if (result == ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    return ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto cleanup;
  }

  if (type == dns_rdatatype_deleg) {
    /* Warn if we don't have at least one ADT key */
    bool adt = false;
    for (size_t i = 0; i < nkeys; i++) {
      if (ADT(keys[i])) {
        adt = true;
        break;
      }
    }
    if (!adt) {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "WARNING: signing DELEG but no DNSKEY "
             "with the ADT flag is present");
    }
  }

  for (size_t i = 0; i < nkeys; i++) {
    /* Don't add signatures for offline or inactive keys */
    if (!dst_key_isprivate(keys[i]) && !offlineksk) {
      continue;
    }
    if (dst_key_inactive(keys[i]) && !offlineksk) {
      continue;
    }

    if (use_kasp) {
      /*
       * A dnssec-policy is found. Check what RRsets this
       * key should sign.
       */
      isc_result_t kresult;
      isc_stdtime_t when;
      bool ksk = false;
      bool zsk = false;
      bool have_zsk = false;

      kresult = dst_key_getbool(keys[i], DST_BOOL_KSK, &ksk);
      if (kresult != ISC_R_SUCCESS) {
        if (KSK(keys[i])) {
          ksk = true;
        }
      }
      kresult = dst_key_getbool(keys[i], DST_BOOL_ZSK, &zsk);
      if (kresult != ISC_R_SUCCESS) {
        if (!KSK(keys[i])) {
          zsk = true;
        }
      }

      /*
       * Don't consider inactive keys or offline keys.
       */
      if (!dst_key_isprivate(keys[i]) && offlineksk && zsk) {
        continue;
      }
      if (dst_key_inactive(keys[i]) && offlineksk && zsk) {
        continue;
      }

      if (offlineksk) {
        have_zsk = true;
      } else {
        (void)dst_key_have_ksk_and_zsk(keys, nkeys, i,
                     true, ksk, zsk,
                     NULL, &have_zsk);
      }

      if (dns_rdatatype_iskeymaterial(type)) {
        /*
         * DNSKEY RRset is signed with KSK.
         * CDS and CDNSKEY RRsets too (RFC 7344, 4.1).
         */
        if (!ksk) {
          continue;
        }
      } else if (!zsk) {
        /*
         * Other RRsets are signed with ZSK.
         */
        if (type != dns_rdatatype_soa &&
            type != zone->privatetype)
        {
          continue;
        }
        if (have_zsk) {
          continue;
        }
      } else if (!dst_key_is_signing(keys[i], DST_BOOL_ZSK,
                   now, &when))
      {
        /*
         * This key is not active for zone-signing.
         */
        continue;
      }
    } else if (!REVOKE(keys[i])) {
      /*
       * Don't consider inactive keys, however the KSK may be
       * temporary offline, so do consider keys which private
       * key files are unavailable.
       */
      bool both = dst_key_have_ksk_and_zsk(
        keys, nkeys, i, false, KSK(keys[i]),
        !KSK(keys[i]), NULL, NULL);
      if (both) {
        /*
         * CDS and CDNSKEY are signed with KSK (RFC
         * 7344, 4.1).
         */
        if (dns_rdatatype_iskeymaterial(type)) {
          if (!KSK(keys[i])) {
            continue;
          }
        } else if (KSK(keys[i])) {
          continue;
        }
      }
    }

    /*
     * If this key is revoked, it may only sign the DNSKEY RRset.
     */
    if (REVOKE(keys[i]) && type != dns_rdatatype_dnskey) {
      continue;
    }

    /* Calculate the signature, creating a RRSIG RDATA. */
    isc_buffer_clear(&buffer);

    if (offlineksk && dns_rdatatype_iskeymaterial(type)) {
      /* Look up the signature in the SKR bundle */
      dns_skrbundle_t *bundle = dns_zone_getskrbundle(zone);
      if (bundle == NULL) {
        CLEANUP(DNS_R_NOSKRBUNDLE);
      }
      CHECK(dns_skrbundle_getsig(bundle, keys[i], type,
               &sig_rdata));
    } else {
      CHECK(dns_dnssec_sign(name, &rdataset, keys[i],
                &inception, &expire, mctx,
                &buffer, &sig_rdata));
    }

    /* Update the database and journal with the RRSIG. */
    /* XXX inefficient - will cause dataset merging */
    CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADDRESIGN, name,
            rdataset.ttl, &sig_rdata));
    dns_rdata_reset(&sig_rdata);
    isc_buffer_init(&buffer, data, sizeof(data));

    /* Update DNSSEC sign statistics. */
    dnssecsignstats = dns_zone_getdnssecsignstats(zone);
    if (dnssecsignstats != NULL) {
      /* Generated a new signature. */
      dns_dnssecsignstats_increment(dnssecsignstats,
                  ID(keys[i]),
                  (uint8_t)ALG(keys[i]),
                  dns_dnssecsignstats_sign);
      /* This is a refresh. */
      dns_dnssecsignstats_increment(
        dnssecsignstats, ID(keys[i]),
        (uint8_t)ALG(keys[i]),
        dns_dnssecsignstats_refresh);
    }
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

static void
calculate_rrsig_validity(dns_zone_t *zone, isc_stdtime_t now,
       isc_stdtime_t *inception, isc_stdtime_t *soaexpire,
       isc_stdtime_t *expire, isc_stdtime_t *fullexpire) {
  REQUIRE(inception != NULL);
  REQUIRE(soaexpire != NULL);
  /* expire and fullexpire are optional */

  isc_stdtime_t jitter = DEFAULT_JITTER;
  isc_stdtime_t sigvalidity = dns_zone_getsigvalidityinterval(zone);
  isc_stdtime_t shortjitter = 0, fulljitter = 0;

  if (zone->kasp != NULL) {
    jitter = dns_kasp_sigjitter(zone->kasp);
    sigvalidity = dns_kasp_sigvalidity(zone->kasp);
    INSIST(jitter <= sigvalidity);
  }

  if (jitter > sigvalidity) {
    jitter = sigvalidity;
  }

  *inception = now - 3600; /* Allow for clock skew. */
  *soaexpire = now + sigvalidity;

  /*
   * Spread out signatures over time if they happen to be
   * clumped.  We don't do this for each add_sigs() call as
   * we still want some clustering to occur.  In normal operations
   * the records should be re-signed as they fall due and they should
   * already be spread out.  However if the server is off for a
   * period we need to ensure that the clusters don't become
   * synchronised by using the full jitter range.
   */
  if (sigvalidity >= 3600U) {
    if (sigvalidity > 7200U) {
      shortjitter = isc_random_uniform(3600);
      fulljitter = isc_random_uniform(jitter);
    } else {
      shortjitter = fulljitter = isc_random_uniform(1200);
    }
  }

  SET_IF_NOT_NULL(expire, *soaexpire - shortjitter - 1);
  SET_IF_NOT_NULL(fullexpire, *soaexpire - fulljitter - 1);
}

static void
zone_resigninc(dns_zone_t *zone) {
  dns_db_t *db = NULL;
  dns_dbversion_t *version = NULL;
  dns_diff_t _sig_diff;
  dns__zonediff_t zonediff;
  dns_fixedname_t fixed;
  dns_name_t *name;
  dns_typepair_t typepair;
  dst_key_t *zone_keys[DNS_MAXZONEKEYS];
  isc_result_t result;
  isc_stdtime_t now, inception, soaexpire, expire, fullexpire, stop;
  unsigned int i;
  unsigned int nkeys = 0;
  isc_stdtime_t resign;

  ENTER;

  dns_diff_init(zone->mctx, &_sig_diff);
  zonediff_init(&zonediff, &_sig_diff);

  /*
   * Zone is frozen. Pause for 5 minutes.
   */
  if (zone->update_disabled) {
    CLEANUP(ISC_R_FAILURE);
  }

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    CLEANUP(ISC_R_FAILURE);
  }

  result = dns_db_newversion(db, &version);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "zone_resigninc:dns_db_newversion -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  now = isc_stdtime_now();

  result = dns_zone_findkeys(zone, db, version, now, zone->mctx,
           DNS_MAXZONEKEYS, zone_keys, &nkeys);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "zone_resigninc:dns_zone_findkeys -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  calculate_rrsig_validity(zone, now, &inception, &soaexpire, &expire,
         &fullexpire);

  stop = now + 5;

  name = dns_fixedname_initname(&fixed);
  result = dns_db_getsigningtime(db, &resign, name, &typepair);
  if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "zone_resigninc:dns_db_getsigningtime -> %s",
           isc_result_totext(result));
  }

  i = 0;
  while (result == ISC_R_SUCCESS) {
    dns_rdatatype_t covers = DNS_TYPEPAIR_COVERS(typepair);

    resign -= dns_zone_getsigresigninginterval(zone);

    /*
     * Stop if we hit the SOA as that means we have walked the
     * entire zone.  The SOA record should always be the most
     * recent signature.
     */
    /* XXXMPA increase number of RRsets signed pre call */
    if ((covers == dns_rdatatype_soa &&
         dns_name_equal(name, &zone->origin)) ||
        i++ > zone->signatures || resign > stop)
    {
      break;
    }

    result = del_sigs(zone, db, version, name, covers, &zonediff,
          zone_keys, nkeys, now, true);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "zone_resigninc:del_sigs -> %s",
             isc_result_totext(result));
      break;
    }

    /*
     * If re-signing is over 5 minutes late use 'fullexpire'
     * to redistribute the signature over the complete
     * re-signing window, otherwise only add a small amount
     * of jitter.
     */
    result = add_sigs(db, version, name, zone, covers,
          zonediff.diff, zone_keys, nkeys, zone->mctx,
          now, inception,
          resign > (now - 300) ? expire : fullexpire);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "zone_resigninc:add_sigs -> %s",
             isc_result_totext(result));
      break;
    }
    result = dns_db_getsigningtime(db, &resign, name, &typepair);
    if (nkeys == 0 && result == ISC_R_NOTFOUND) {
      result = ISC_R_SUCCESS;
      break;
    }
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "zone_resigninc:dns_db_getsigningtime -> "
             "%s",
             isc_result_totext(result));
    }
  }

  if (result != ISC_R_NOMORE) {
    CHECK(result);
  }

  result = del_sigs(zone, db, version, &zone->origin, dns_rdatatype_soa,
        &zonediff, zone_keys, nkeys, now, true);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "zone_resigninc:del_sigs -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  /*
   * Did we change anything in the zone?
   */
  if (ISC_LIST_EMPTY(zonediff.diff->tuples)) {
    /*
     * Commit the changes if any key has been marked as offline.
     */
    if (zonediff.offline) {
      dns_db_closeversion(db, &version, true);
    }
    goto cleanup;
  }

  /* Increment SOA serial if we have made changes */
  result = update_soa_serial(zone, db, version, zonediff.diff, zone->mctx,
           zone->updatemethod);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "zone_resigninc:update_soa_serial -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  /*
   * Generate maximum life time signatures so that the above loop
   * termination is sensible.
   */
  result = add_sigs(db, version, &zone->origin, zone, dns_rdatatype_soa,
        zonediff.diff, zone_keys, nkeys, zone->mctx, now,
        inception, soaexpire);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "zone_resigninc:add_sigs -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  /* Write changes to journal file. */
  CHECK(zone_journal(zone, zonediff.diff, NULL, "zone_resigninc"));

  /* Everything has succeeded. Commit the changes. */
  dns_db_closeversion(db, &version, true);

cleanup:
  dns_diff_clear(&_sig_diff);
  for (i = 0; i < nkeys; i++) {
    dst_key_free(&zone_keys[i]);
  }
  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
    dns_db_detach(&db);
  } else if (db != NULL) {
    dns_db_detach(&db);
  }

  LOCK_ZONE(zone);
  if (result == ISC_R_SUCCESS) {
    dns__zone_set_resigntime(zone);
    zone_needdump(zone, DNS_DUMP_DELAY);
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
  } else {
    /*
     * Something failed.  Retry in 5 minutes.
     */
    isc_interval_t ival;
    isc_interval_set(&ival, 300, 0);
    isc_time_nowplusinterval(&zone->resigntime, &ival);
  }
  UNLOCK_ZONE(zone);

  INSIST(version == NULL);
}

static isc_result_t
next_active(dns_db_t *db, dns_dbversion_t *version, dns_name_t *oldname,
      dns_name_t *newname, bool bottom) {
  isc_result_t result;
  dns_dbiterator_t *dbit = NULL;
  dns_rdatasetiter_t *rdsit = NULL;
  dns_dbnode_t *node = NULL;

  CHECK(dns_db_createiterator(db, DNS_DB_NONSEC3, &dbit));
  CHECK(dns_dbiterator_seek(dbit, oldname));
  do {
    result = dns_dbiterator_next(dbit);
    if (result == ISC_R_NOMORE) {
      CHECK(dns_dbiterator_first(dbit));
    }
    CHECK(dns_dbiterator_current(dbit, &node, newname));
    if (bottom && dns_name_issubdomain(newname, oldname) &&
        !dns_name_equal(newname, oldname))
    {
      dns_db_detachnode(&node);
      continue;
    }
    /*
     * Is this node empty?
     */
    CHECK(dns_db_allrdatasets(db, node, version, 0, 0, &rdsit));
    result = dns_rdatasetiter_first(rdsit);
    dns_db_detachnode(&node);
    dns_rdatasetiter_destroy(&rdsit);
    if (result != ISC_R_NOMORE) {
      break;
    }
  } while (1);
cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (dbit != NULL) {
    dns_dbiterator_destroy(&dbit);
  }
  return result;
}

static bool
signed_with_good_key(dns_zone_t *zone, dns_db_t *db, dns_dbnode_t *node,
         dns_dbversion_t *version, dns_rdatatype_t type,
         dst_key_t *key, bool fullsign) {
  isc_result_t result;
  dns_rdataset_t rdataset;
  dns_rdata_rrsig_t rrsig;
  int count = 0;
  dns_kasp_t *kasp = zone->kasp;

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, version, dns_rdatatype_rrsig,
             type, 0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    return false;
  }
  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &rrsig);
    INSIST(result == ISC_R_SUCCESS);
    dst_algorithm_t algorithm;
    algorithm = dst_algorithm_fromdata(
      rrsig.algorithm, rrsig.signature, rrsig.siglen);
    if (algorithm == dst_key_alg(key) &&
        rrsig.keyid == dst_key_id(key))
    {
      dns_rdataset_disassociate(&rdataset);
      return true;
    }
    if (algorithm == dst_key_alg(key)) {
      count++;
    }
  }

  if (zone->kasp != NULL && !fullsign) {
    int zsk_count = 0;
    bool approved;

    KASP_LOCK(kasp);
    ISC_LIST_FOREACH(dns_kasp_keys(kasp), kkey, link) {
      if (dns_kasp_key_algorithm(kkey) != dst_key_alg(key)) {
        continue;
      }
      if (dns_kasp_key_zsk(kkey)) {
        zsk_count++;
      }
    }
    KASP_UNLOCK(kasp);

    if (dns_rdatatype_iskeymaterial(type)) {
      /*
       * CDS and CDNSKEY are signed with KSK like DNSKEY.
       * (RFC 7344, section 4.1 specifies that they must
       * be signed with a key in the current DS RRset,
       * which would only include KSK's.)
       */
      approved = false;
    } else {
      approved = (zsk_count == count);
    }

    dns_rdataset_disassociate(&rdataset);
    return approved;
  }

  dns_rdataset_disassociate(&rdataset);
  return false;
}

static isc_result_t
add_nsec(dns_db_t *db, dns_dbversion_t *version, dns_name_t *name,
   dns_dbnode_t *node, dns_ttl_t ttl, bool bottom, dns_diff_t *diff) {
  dns_fixedname_t fixed;
  dns_name_t *next;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  isc_result_t result;
  unsigned char nsecbuffer[DNS_NSEC_BUFFERSIZE];

  next = dns_fixedname_initname(&fixed);

  CHECK(next_active(db, version, name, next, bottom));
  CHECK(dns_nsec_buildrdata(db, version, node, next, nsecbuffer, &rdata));
  CHECK(update_one_rr(db, version, diff, DNS_DIFFOP_ADD, name, ttl,
          &rdata));
cleanup:
  return result;
}

static isc_result_t
check_if_bottom_of_zone(dns_db_t *db, dns_dbnode_t *node,
      dns_dbversion_t *version, bool *is_bottom_of_zone) {
  isc_result_t result;
  dns_rdatasetiter_t *iterator = NULL;
  bool seen_soa = false, seen_ns = false;
  bool seen_dname = false, seen_deleg = false;

  REQUIRE(is_bottom_of_zone != NULL);

  result = dns_db_allrdatasets(db, node, version, 0, 0, &iterator);
  if (result != ISC_R_SUCCESS) {
    if (result == ISC_R_NOTFOUND) {
      result = ISC_R_SUCCESS;
    }
    return result;
  }

  DNS_RDATASETITER_FOREACH(iterator) {
    dns_rdataset_t rdataset = DNS_RDATASET_INIT;
    dns_rdatasetiter_current(iterator, &rdataset);
    switch (rdataset.type) {
    case dns_rdatatype_soa:
      seen_soa = true;
      break;
    case dns_rdatatype_ns:
      seen_ns = true;
      break;
    case dns_rdatatype_deleg:
      seen_deleg = true;
      break;
    case dns_rdatatype_dname:
      seen_dname = true;
      break;
    }
    dns_rdataset_disassociate(&rdataset);
  }

  if ((seen_ns && !seen_soa) || seen_dname || seen_deleg) {
    *is_bottom_of_zone = true;
  }

  dns_rdatasetiter_destroy(&iterator);
  return ISC_R_SUCCESS;
}

typedef struct seen {
  bool rr;
  bool soa;
  bool ns;
  bool nsec;
  bool nsec3;
  bool ds;
  bool dname;
  bool deleg;
} seen_t;

static isc_result_t
allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
       dns_rdatasetiter_t **iterp, seen_t *seen) {
  dns_rdataset_t rdataset = DNS_RDATASET_INIT;

  *seen = (seen_t){};

  RETERR(dns_db_allrdatasets(db, node, version, 0, 0, iterp));

  DNS_RDATASETITER_FOREACH(*iterp) {
    dns_rdatasetiter_current(*iterp, &rdataset);

    if (rdataset.type == dns_rdatatype_rrsig) {
      dns_rdataset_disassociate(&rdataset);
      continue;
    }

    (*seen).rr = true;

    if (rdataset.type == dns_rdatatype_soa) {
      (*seen).soa = true;
    } else if (rdataset.type == dns_rdatatype_ns) {
      (*seen).ns = true;
    } else if (rdataset.type == dns_rdatatype_ds) {
      (*seen).ds = true;
    } else if (rdataset.type == dns_rdatatype_dname) {
      (*seen).dname = true;
    } else if (rdataset.type == dns_rdatatype_nsec) {
      (*seen).nsec = true;
    } else if (rdataset.type == dns_rdatatype_nsec3) {
      (*seen).nsec3 = true;
    } else if (rdataset.type == dns_rdatatype_deleg) {
      (*seen).deleg = true;
    }

    dns_rdataset_disassociate(&rdataset);
  }

  return ISC_R_SUCCESS;
}

static isc_result_t
sign_a_node(dns_db_t *db, dns_zone_t *zone, dns_name_t *name,
      dns_dbnode_t *node, dns_dbversion_t *version, bool build_nsec3,
      bool build_nsec, dst_key_t *key, isc_stdtime_t now,
      isc_stdtime_t inception, isc_stdtime_t expire, dns_ttl_t nsecttl,
      bool both, bool is_ksk, bool is_zsk, bool fullsign,
      bool is_bottom_of_zone, bool have_adt, dns_diff_t *diff,
      int32_t *signatures, isc_mem_t *mctx) {
  isc_result_t result;
  dns_rdatasetiter_t *iterator = NULL;
  dns_rdataset_t rdataset = DNS_RDATASET_INIT;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_stats_t *dnssecsignstats;
  bool offlineksk = false;
  isc_buffer_t buffer;
  unsigned char data[DNS_RDATA_MAXLENGTH];
  seen_t seen;

  if (zone->kasp != NULL) {
    offlineksk = dns_kasp_offlineksk(zone->kasp);
  }

  result = allrdatasets(db, node, version, &iterator, &seen);
  if (result != ISC_R_SUCCESS) {
    if (result == ISC_R_NOTFOUND) {
      result = ISC_R_SUCCESS;
    }
    return result;
  }

  isc_buffer_init(&buffer, data, sizeof(data));

  /*
   * Going from insecure to NSEC3.
   * Don't generate NSEC3 records for NSEC3 records.
   */
  if (build_nsec3 && !seen.nsec3 && seen.rr) {
    bool unsecure = !seen.ds && seen.ns && !seen.soa;
    CHECK(dns_nsec3_addnsec3s(db, version, name, nsecttl, unsecure,
            diff));
    (*signatures)--;
  }
  /*
   * Going from insecure to NSEC.
   * Don't generate NSEC records for NSEC3 records.
   */
  if (build_nsec && !seen.nsec3 && !seen.nsec && seen.rr) {
    /*
     * Build a NSEC record except at the origin.
     */
    if (!dns_name_equal(name, dns_db_origin(db))) {
      CHECK(add_nsec(db, version, name, node, nsecttl,
               is_bottom_of_zone, diff));
      /* Count a NSEC generation as a signature generation. */
      (*signatures)--;
    }
  }

  DNS_RDATASETITER_FOREACH(iterator) {
    isc_stdtime_t when;

    dns_rdataset_cleanup(&rdataset);

    dns_rdatasetiter_current(iterator, &rdataset);
    if (rdataset.type == dns_rdatatype_soa ||
        rdataset.type == dns_rdatatype_rrsig)
    {
      continue;
    }
    if (dns_rdatatype_iskeymaterial(rdataset.type)) {
      /*
       * CDS and CDNSKEY are signed with KSK like DNSKEY.
       * (RFC 7344, section 4.1 specifies that they must
       * be signed with a key in the current DS RRset,
       * which would only include KSK's.)
       */
      if (!is_ksk && both) {
        continue;
      }
    } else if (!is_zsk && both) {
      continue;
    } else if (is_zsk &&
         !dst_key_is_signing(key, DST_BOOL_ZSK, now, &when))
    {
      /* Only applies to dnssec-policy. */
      if (zone->kasp != NULL) {
        continue;
      }
    }

    if (seen.ns && !seen.soa && rdataset.type != dns_rdatatype_ds &&
        rdataset.type != dns_rdatatype_deleg &&
        rdataset.type != dns_rdatatype_nsec)
    {
      continue;
    }
    if (signed_with_good_key(zone, db, node, version, rdataset.type,
           key, fullsign))
    {
      continue;
    }

    if (rdataset.type == dns_rdatatype_deleg && !have_adt) {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "WARNING: signing DELEG but no DNSKEY "
             "with the ADT flag is present");
    }

    /* Calculate the signature, creating a RRSIG RDATA. */
    isc_buffer_clear(&buffer);
    if (offlineksk && dns_rdatatype_iskeymaterial(rdataset.type)) {
      /* Look up the signature in the SKR bundle */
      dns_skrbundle_t *bundle = dns_zone_getskrbundle(zone);
      if (bundle == NULL) {
        CLEANUP(DNS_R_NOSKRBUNDLE);
      }
      CHECK(dns_skrbundle_getsig(bundle, key, rdataset.type,
               &rdata));
    } else {
      CHECK(dns_dnssec_sign(name, &rdataset, key, &inception,
                &expire, mctx, &buffer, &rdata));
    }

    /* Update the database and journal with the RRSIG. */
    /* XXX inefficient - will cause dataset merging */
    CHECK(update_one_rr(db, version, diff, DNS_DIFFOP_ADDRESIGN,
            name, rdataset.ttl, &rdata));
    dns_rdata_reset(&rdata);

    /* Update DNSSEC sign statistics. */
    dnssecsignstats = dns_zone_getdnssecsignstats(zone);
    if (dnssecsignstats != NULL) {
      /* Generated a new signature. */
      dns_dnssecsignstats_increment(dnssecsignstats, ID(key),
                  ALG(key),
                  dns_dnssecsignstats_sign);
      /* This is a refresh. */
      dns_dnssecsignstats_increment(
        dnssecsignstats, ID(key), ALG(key),
        dns_dnssecsignstats_refresh);
    }

    (*signatures)--;
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  if (iterator != NULL) {
    dns_rdatasetiter_destroy(&iterator);
  }
  return result;
}

/*
 * If 'update_only' is set then don't create a NSEC RRset if it doesn't exist.
 */
static isc_result_t
updatesecure(dns_db_t *db, dns_dbversion_t *version, dns_name_t *name,
       dns_ttl_t nsecttl, bool update_only, dns_diff_t *diff) {
  isc_result_t result;
  dns_rdataset_t rdataset;
  dns_dbnode_t *node = NULL;

  CHECK(dns_db_getoriginnode(db, &node));
  if (update_only) {
    dns_rdataset_init(&rdataset);
    result = dns_db_findrdataset(
      db, node, version, dns_rdatatype_nsec,
      dns_rdatatype_none, 0, &rdataset, NULL);
    dns_rdataset_cleanup(&rdataset);
    if (result == ISC_R_NOTFOUND) {
      goto success;
    }
    CHECK(result);
  }
  CHECK(delete_nsec(db, version, node, name, diff));
  CHECK(add_nsec(db, version, name, node, nsecttl, false, diff));
success:
  result = ISC_R_SUCCESS;
cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

static isc_result_t
updatesignwithkey(dns_zone_t *zone, dns_signing_t *signing,
      dns_dbversion_t *version, bool build_nsec3, dns_ttl_t nsecttl,
      dns_diff_t *diff) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset;
  bool seen_done = false;
  bool have_rr = false;

  dns_rdataset_init(&rdataset);
  CHECK(dns_db_getoriginnode(signing->db, &node));

  result = dns_db_findrdataset(signing->db, node, version,
             zone->privatetype, dns_rdatatype_none, 0,
             &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    result = ISC_R_SUCCESS;
    goto cleanup;
  }
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    unsigned char alg = dst_algorithm_tosecalg(signing->algorithm);

    dns_rdataset_current(&rdataset, &rdata);
    /*
     * If we don't match the algorithm or keyid skip the record.
     */
    if ((rdata.length != SIGNING_RECORD_SIZE &&
         rdata.length != OLD_SIGNING_RECORD_SIZE) ||
        rdata.data[0] == 0 || rdata.data[0] != alg ||
        rdata.data[1] != ((signing->keyid >> 8) & 0xff) ||
        rdata.data[2] != (signing->keyid & 0xff) ||
        (rdata.length == SIGNING_RECORD_SIZE &&
         (rdata.data[5] != (signing->algorithm >> 8 & 0xff) ||
          rdata.data[6] != (signing->algorithm & 0xff))))
    {
      have_rr = true;
      continue;
    }
    /*
     * We have a match.  If we were signing (!signing->deleteit)
     * and we already have a record indicating that we have
     * finished signing (rdata.data[4] != 0) then keep it.
     * Otherwise it needs to be deleted as we have removed all
     * the signatures (signing->deleteit), so any record indicating
     * completion is now out of date, or we have finished signing
     * with the new record so we no longer need to remember that
     * we need to sign the zone with the matching key across a
     * nameserver re-start.
     */
    if (!signing->deleteit && rdata.data[4] != 0) {
      seen_done = true;
      have_rr = true;
    } else {
      CHECK(update_one_rr(signing->db, version, diff,
              DNS_DIFFOP_DEL, &zone->origin,
              rdataset.ttl, &rdata));
    }
  }

  if (!signing->deleteit && !seen_done) {
    /*
     * If we were signing then we need to indicate that we have
     * finished signing the zone with this key.  If it is already
     * there we don't need to add it a second time.
     */
    unsigned char data[SIGNING_RECORD_SIZE] = {
      dst_algorithm_tosecalg(signing->algorithm),
      (signing->keyid >> 8) & 0xff,
      signing->keyid & 0xff,
      0,
      1,
      (signing->algorithm >> 8) & 0xff,
      signing->algorithm & 0xff,
    };
    dns_rdata_t rdata = (dns_rdata_t){
      .length = signing->algorithm < 256
            ? OLD_SIGNING_RECORD_SIZE
            : sizeof(data),
      .data = data,
      .type = zone->privatetype,
      .rdclass = dns_db_class(signing->db),
      .link = ISC_LINK_INITIALIZER,
    };
    /*
     * data[0] can't be 0 as that is used to signal that the
     * record is being used to for NSEC/NSEC3 chains generation.
     * Set it to 255 instead.
     */
    if (data[0] == 0) {
      data[0] = 255;
    }
    CHECK(update_one_rr(signing->db, version, diff, DNS_DIFFOP_ADD,
            &zone->origin, rdataset.ttl, &rdata));
  } else if (!have_rr) {
    dns_name_t *origin = dns_db_origin(signing->db);
    /*
     * Rebuild the NSEC/NSEC3 record for the origin as we no
     * longer have any private records.
     */
    if (build_nsec3) {
      CHECK(dns_nsec3_addnsec3s(signing->db, version, origin,
              nsecttl, false, diff));
    }
    CHECK(updatesecure(signing->db, version, origin, nsecttl, true,
           diff));
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

/*
 * Called from zone_nsec3chain() in order to update zone records indicating
 * processing status of given NSEC3 chain:
 *
 *   - If the supplied dns_nsec3chain_t structure has been fully processed
 *     (which is indicated by "active" being set to false):
 *
 *       - remove all NSEC3PARAM records matching the relevant NSEC3 chain,
 *
 *       - remove all private-type records containing NSEC3PARAM RDATA matching
 *         the relevant NSEC3 chain.
 *
 *   - If the supplied dns_nsec3chain_t structure has not been fully processed
 *     (which is indicated by "active" being set to true), only remove the
 *     NSEC3PARAM record which matches the relevant NSEC3 chain and has the
 *     "flags" field set to 0.
 *
 *   - If given NSEC3 chain is being added, add an NSEC3PARAM record contained
 *     in the relevant private-type record, but with the "flags" field set to
 *     0, indicating that this NSEC3 chain is now complete for this zone.
 *
 * Note that this function is called at different processing stages for NSEC3
 * chain additions vs. removals and needs to handle all cases properly.
 */
static isc_result_t
fixup_nsec3param(dns_db_t *db, dns_dbversion_t *ver, dns_nsec3chain_t *chain,
     bool active, dns_rdatatype_t privatetype, dns_diff_t *diff) {
  dns_dbnode_t *node = NULL;
  dns_name_t *name = dns_db_origin(db);
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_rdataset_t rdataset;
  dns_rdata_nsec3param_t nsec3param;
  dns_rdata_soa_t soa;
  isc_result_t result;
  isc_buffer_t buffer;
  unsigned char parambuf[DNS_NSEC3PARAM_BUFFERSIZE];
  dns_ttl_t ttl = 0;
  bool nseconly = false, nsec3ok = false;

  dns_rdataset_init(&rdataset);

  result = dns_db_getoriginnode(db, &node);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  /* Default TTL is SOA MINIMUM */
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_soa, 0, 0,
             &rdataset, NULL);
  if (result == ISC_R_SUCCESS) {
    CHECK(dns_rdataset_first(&rdataset));
    dns_rdataset_current(&rdataset, &rdata);
    CHECK(dns_rdata_tostruct(&rdata, &soa));
    ttl = soa.minimum;
    dns_rdata_reset(&rdata);
  }
  dns_rdataset_cleanup(&rdataset);

  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3param, 0,
             0, &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    goto try_private;
  }
  if (result != ISC_R_SUCCESS) {
    goto cleanup;
  }

  /*
   * Delete all NSEC3PARAM records which match that in nsec3chain.
   */
  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdataset_current(&rdataset, &rdata);
    CHECK(dns_rdata_tostruct(&rdata, &nsec3param));

    if (nsec3param.hash != chain->nsec3param.hash ||
        (active && nsec3param.flags != 0) ||
        nsec3param.iterations != chain->nsec3param.iterations ||
        nsec3param.salt.length != chain->nsec3param.salt.length ||
        memcmp(nsec3param.salt.base, chain->nsec3param.salt.base,
         nsec3param.salt.length))
    {
      /*
       * If the SOA minimum is different to the current TTL,
       * delete the record.  We will re-add it with the new
       * TTL below.
       */
      if (rdataset.ttl != ttl) {
        CHECK(update_one_rr(db, ver, diff,
                DNS_DIFFOP_DEL, name,
                rdataset.ttl, &rdata));
      }
      dns_rdata_reset(&rdata);
      continue;
    }

    CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name,
            rdataset.ttl, &rdata));
    dns_rdata_reset(&rdata);
  }

  /*
   * Restore any NSEC3PARAM records that we deleted to change the TTL.
   */
  if (rdataset.ttl != ttl) {
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdataset_current(&rdataset, &rdata);
      CHECK(dns_rdata_tostruct(&rdata, &nsec3param));

      if (nsec3param.hash != chain->nsec3param.hash ||
          (active && nsec3param.flags != 0) ||
          nsec3param.iterations !=
            chain->nsec3param.iterations ||
          nsec3param.salt.length !=
            chain->nsec3param.salt.length ||
          memcmp(nsec3param.salt.base,
           chain->nsec3param.salt.base,
           nsec3param.salt.length))
      {
        CHECK(update_one_rr(db, ver, diff,
                DNS_DIFFOP_ADD, name, ttl,
                &rdata));
      }
      dns_rdata_reset(&rdata);
    }
  }

  dns_rdataset_disassociate(&rdataset);

try_private:

  if (active) {
    goto add;
  }

  result = dns_nsec_nseconly(db, ver, diff, &nseconly);
  nsec3ok = (result == ISC_R_SUCCESS && !nseconly);

  /*
   * Delete all private records which match that in nsec3chain.
   */
  result = dns_db_findrdataset(db, node, ver, privatetype, 0, 0,
             &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    goto add;
  }
  CHECK(result);

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t private = DNS_RDATA_INIT;
    unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];

    dns_rdataset_current(&rdataset, &private);
    if (!dns_nsec3param_fromprivate(&private, &rdata, buf,
            sizeof(buf)))
    {
      continue;
    }
    CHECK(dns_rdata_tostruct(&rdata, &nsec3param));
    dns_rdata_reset(&rdata);

    if ((!nsec3ok &&
         (nsec3param.flags & DNS_NSEC3FLAG_INITIAL) != 0) ||
        nsec3param.hash != chain->nsec3param.hash ||
        nsec3param.iterations != chain->nsec3param.iterations ||
        nsec3param.salt.length != chain->nsec3param.salt.length ||
        memcmp(nsec3param.salt.base, chain->nsec3param.salt.base,
         nsec3param.salt.length))
    {
      continue;
    }

    CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name,
            rdataset.ttl, &private));
  }

add:
  if ((chain->nsec3param.flags & DNS_NSEC3FLAG_REMOVE) != 0) {
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  /*
   * Add a NSEC3PARAM record which matches that in nsec3chain but
   * with all flags bits cleared.
   *
   * Note: we do not clear chain->nsec3param.flags as this change
   * may be reversed.
   */
  isc_buffer_init(&buffer, &parambuf, sizeof(parambuf));
  CHECK(dns_rdata_fromstruct(&rdata, dns_db_class(db),
           dns_rdatatype_nsec3param, &chain->nsec3param,
           &buffer));
  rdata.data[1] = 0; /* Clear flag bits. */
  CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADD, name, ttl, &rdata));

cleanup:
  dns_db_detachnode(&node);
  dns_rdataset_cleanup(&rdataset);
  return result;
}

static isc_result_t
delete_nsec(dns_db_t *db, dns_dbversion_t *ver, dns_dbnode_t *node,
      dns_name_t *name, dns_diff_t *diff) {
  dns_rdataset_t rdataset;
  isc_result_t result;

  dns_rdataset_init(&rdataset);

  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec, 0, 0,
             &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    return ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS) {
    return result;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(&rdataset, &rdata);
    CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name,
            rdataset.ttl, &rdata));
  }

cleanup:
  dns_rdataset_disassociate(&rdataset);
  return result;
}

static isc_result_t
deletematchingnsec3(dns_db_t *db, dns_dbversion_t *ver, dns_dbnode_t *node,
        dns_name_t *name, const dns_rdata_nsec3param_t *param,
        dns_diff_t *diff) {
  dns_rdataset_t rdataset;
  dns_rdata_nsec3_t nsec3;
  isc_result_t result;

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3, 0, 0,
             &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    return ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS) {
    return result;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(&rdataset, &rdata);
    CHECK(dns_rdata_tostruct(&rdata, &nsec3));
    if (nsec3.hash != param->hash ||
        nsec3.iterations != param->iterations ||
        nsec3.salt.length != param->salt.length ||
        memcmp(nsec3.salt.base, param->salt.base,
         nsec3.salt.length))
    {
      continue;
    }
    CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name,
            rdataset.ttl, &rdata));
  }

cleanup:
  dns_rdataset_disassociate(&rdataset);
  return result;
}

static isc_result_t
need_nsec_chain(dns_db_t *db, dns_dbversion_t *ver,
    const dns_rdata_nsec3param_t *param, bool *answer) {
  dns_dbnode_t *node = NULL;
  dns_rdata_nsec3param_t myparam;
  dns_rdataset_t rdataset;
  isc_result_t result;

  *answer = false;

  result = dns_db_getoriginnode(db, &node);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  dns_rdataset_init(&rdataset);

  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec, 0, 0,
             &rdataset, NULL);
  if (result == ISC_R_SUCCESS) {
    dns_rdataset_disassociate(&rdataset);
    dns_db_detachnode(&node);
    return result;
  }
  if (result != ISC_R_NOTFOUND) {
    dns_db_detachnode(&node);
    return result;
  }

  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3param, 0,
             0, &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    *answer = true;
    dns_db_detachnode(&node);
    return ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS) {
    dns_db_detachnode(&node);
    return result;
  }

  bool active = false;
  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &rdata);
    CHECK(dns_rdata_tostruct(&rdata, &myparam));

    /*
     * Ignore any NSEC3PARAM removals.
     */
    if (NSEC3REMOVE(myparam.flags)) {
      continue;
    }
    /*
     * Ignore the chain that we are in the process of deleting.
     */
    if (myparam.hash == param->hash &&
        myparam.iterations == param->iterations &&
        myparam.salt.length == param->salt.length &&
        !memcmp(myparam.salt.base, param->salt.base,
          myparam.salt.length))
    {
      continue;
    }

    /*
     * Found an active NSEC3 chain.
     */
    active = true;
    break;
  }

  *answer = !active;

cleanup:
  dns_rdataset_cleanup(&rdataset);
  dns_db_detachnode(&node);
  return result;
}

/*%
 * Given a tuple which is part of a diff, return a pointer to the next tuple in
 * that diff which has the same name and type (or NULL if no such tuple is
 * found).
 */
static dns_difftuple_t *
find_next_matching_tuple(dns_difftuple_t *cur) {
  dns_difftuple_t *next = cur;

  while ((next = ISC_LIST_NEXT(next, link)) != NULL) {
    if (cur->rdata.type == next->rdata.type &&
        dns_name_equal(&cur->name, &next->name))
    {
      return next;
    }
  }

  return NULL;
}

/*%
 * Remove all tuples with the same name and type as 'cur' from 'src' and append
 * them to 'dst'.
 */
static void
move_matching_tuples(dns_difftuple_t *cur, dns_diff_t *src, dns_diff_t *dst) {
  do {
    dns_difftuple_t *next = find_next_matching_tuple(cur);
    dns_diff_unlink(src, cur);
    dns_diff_appendminimal(dst, &cur);
    cur = next;
  } while (cur != NULL);
}

/*%
 * Add/remove DNSSEC signatures for the list of "raw" zone changes supplied in
 * 'diff'.  Gradually remove tuples from 'diff' and append them to 'zonediff'
 * along with tuples representing relevant signature changes.
 */
isc_result_t
dns__zone_updatesigs(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *version,
         dst_key_t *zone_keys[], unsigned int nkeys,
         dns_zone_t *zone, isc_stdtime_t inception,
         isc_stdtime_t expire, isc_stdtime_t keyexpire,
         isc_stdtime_t now, dns__zonediff_t *zonediff) {
  dns_difftuple_t *tuple;
  isc_result_t result;

  while ((tuple = ISC_LIST_HEAD(diff->tuples)) != NULL) {
    isc_stdtime_t exp = expire;

    if (keyexpire != 0 &&
        dns_rdatatype_iskeymaterial(tuple->rdata.type))
    {
      exp = keyexpire;
    }

    result = del_sigs(zone, db, version, &tuple->name,
          tuple->rdata.type, zonediff, zone_keys, nkeys,
          now, false);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "dns__zone_updatesigs:del_sigs -> %s",
             isc_result_totext(result));
      return result;
    }
    result = add_sigs(db, version, &tuple->name, zone,
          tuple->rdata.type, zonediff->diff, zone_keys,
          nkeys, zone->mctx, now, inception, exp);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "dns__zone_updatesigs:add_sigs -> %s",
             isc_result_totext(result));
      return result;
    }

    /*
     * Signature changes for all RRs with name tuple->name and type
     * tuple->rdata.type were appended to zonediff->diff.  Now we
     * remove all the "raw" changes with the same name and type
     * from diff (so that they are not processed by this loop
     * again) and append them to zonediff so that they get applied.
     */
    move_matching_tuples(tuple, diff, zonediff->diff);
  }
  return ISC_R_SUCCESS;
}

/*
 * Incrementally build and sign a new NSEC3 chain using the parameters
 * requested.
 */
static void
zone_nsec3chain(dns_zone_t *zone) {
  dns_db_t *db = NULL;
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_diff_t _sig_diff;
  dns_diff_t nsec_diff;
  dns_diff_t nsec3_diff;
  dns_diff_t param_diff;
  dns__zonediff_t zonediff;
  dns_fixedname_t fixed;
  dns_fixedname_t nextfixed;
  dns_name_t *name = NULL, *nextname = NULL;
  dns_nsec3chain_t *nsec3chain = NULL;
  dns_nsec3chainlist_t cleanup;
  dst_key_t *zone_keys[DNS_MAXZONEKEYS];
  int32_t signatures;
  bool delegation;
  bool first;
  isc_result_t result;
  isc_stdtime_t now, inception, soaexpire, expire;
  unsigned int i;
  unsigned int nkeys = 0;
  uint32_t nodes;
  bool unsecure = false;
  seen_t seen;
  dns_rdatasetiter_t *iterator = NULL;
  bool buildnsecchain;
  bool updatensec = false;
  dns_rdatatype_t privatetype = zone->privatetype;

  ENTER;

  name = dns_fixedname_initname(&fixed);
  nextname = dns_fixedname_initname(&nextfixed);
  dns_diff_init(zone->mctx, &param_diff);
  dns_diff_init(zone->mctx, &nsec3_diff);
  dns_diff_init(zone->mctx, &nsec_diff);
  dns_diff_init(zone->mctx, &_sig_diff);
  zonediff_init(&zonediff, &_sig_diff);
  ISC_LIST_INIT(cleanup);

  /*
   * Updates are disabled.  Pause for 5 minutes.
   */
  if (zone->update_disabled) {
    CLEANUP(ISC_R_FAILURE);
  }

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  /*
   * This function is called when zone timer fires, after the latter gets
   * set by zone_addnsec3chain().  If the action triggering the call to
   * zone_addnsec3chain() is closely followed by a zone deletion request,
   * it might turn out that the timer thread will not be woken up until
   * after the zone is deleted by rmzone(), which calls dns_db_detach()
   * for zone->db, causing the latter to become NULL.  Return immediately
   * if that happens.
   */
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    return;
  }

  result = dns_db_newversion(db, &version);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:dns_db_newversion -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  now = isc_stdtime_now();

  result = dns_zone_findkeys(zone, db, version, now, zone->mctx,
           DNS_MAXZONEKEYS, zone_keys, &nkeys);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:dns_zone_findkeys -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  calculate_rrsig_validity(zone, now, &inception, &soaexpire, NULL,
         &expire);

  /*
   * We keep pulling nodes off each iterator in turn until
   * we have no more nodes to pull off or we reach the limits
   * for this quantum.
   */
  nodes = zone->nodes;
  signatures = zone->signatures;
  LOCK_ZONE(zone);
  nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
  UNLOCK_ZONE(zone);
  first = true;

  if (nsec3chain != NULL) {
    nsec3chain->save_delete_nsec = nsec3chain->delete_nsec;
  }
  /*
   * Generate new NSEC3 chains first.
   *
   * The following while loop iterates over nodes in the zone database,
   * updating the NSEC3 chain by calling dns_nsec3_addnsec3() for each of
   * them.  Once all nodes are processed, the "delete_nsec" field is
   * consulted to check whether we are supposed to remove NSEC records
   * from the zone database; if so, the database iterator is reset to
   * point to the first node and the loop traverses all of them again,
   * this time removing NSEC records.  If we hit a node which is obscured
   * by a delegation or a DNAME, nodes are skipped over until we find one
   * that is not obscured by the same obscuring name and then normal
   * processing is resumed.
   *
   * The above is repeated until all requested NSEC3 chain changes are
   * applied or when we reach the limits for this quantum, whichever
   * happens first.
   *
   * Note that the "signatures" variable is only used here to limit the
   * amount of work performed.  Actual DNSSEC signatures are only
   * generated by dns__zone_updatesigs() calls later in this function.
   */
  while (nsec3chain != NULL && nodes-- > 0 && signatures > 0) {
    dns_dbiterator_pause(nsec3chain->dbiterator);

    LOCK_ZONE(zone);
    dns_nsec3chain_t *nextnsec3chain = ISC_LIST_NEXT(nsec3chain,
                 link);

    ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
    if (nsec3chain->done || nsec3chain->db != zone->db) {
      ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain, link);
      ISC_LIST_APPEND(cleanup, nsec3chain, link);
    }
    ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
    UNLOCK_ZONE(zone);
    if (ISC_LIST_TAIL(cleanup) == nsec3chain) {
      goto next_addchain;
    }

    /*
     * Possible future db.
     */
    if (nsec3chain->db != db) {
      goto next_addchain;
    }

    if (NSEC3REMOVE(nsec3chain->nsec3param.flags)) {
      goto next_addchain;
    }

    dns_dbiterator_current(nsec3chain->dbiterator, &node, name);

    if (nsec3chain->delete_nsec) {
      delegation = false;
      dns_dbiterator_pause(nsec3chain->dbiterator);
      CHECK(delete_nsec(db, version, node, name, &nsec_diff));
      goto next_addnode;
    }
    /*
     * On the first pass we need to check if the current node
     * has not been obscured.
     */
    delegation = false;
    unsecure = false;
    if (first) {
      dns_fixedname_t ffound;
      dns_name_t *found;
      found = dns_fixedname_initname(&ffound);
      result = dns_db_find(
        db, name, version, dns_rdatatype_soa,
        DNS_DBFIND_NOWILD, 0, found, NULL, NULL);
      if ((result == DNS_R_DELEGATION ||
           result == DNS_R_DNAME) &&
          !dns_name_equal(name, found))
      {
        /*
         * Remember the obscuring name so that
         * we skip all obscured names.
         */
        dns_name_copy(found, name);
        delegation = true;
        goto next_addnode;
      }
    }

    /*
     * Check to see if this is a bottom of zone node.
     */
    result = allrdatasets(db, node, version, &iterator, &seen);
    if (result == ISC_R_NOTFOUND) {
      /* Empty node? */
      goto next_addnode;
    }
    CHECK(result);

    INSIST(!seen.nsec3);

    dns_rdatasetiter_destroy(&iterator);
    /*
     * Is there a NSEC chain than needs to be cleaned up?
     */
    if (seen.nsec) {
      nsec3chain->seen_nsec = true;
    }

    if (seen.ns && !seen.soa && !seen.ds) {
      unsecure = true;
    }
    if ((seen.ns && !seen.soa) || seen.dname) {
      delegation = true;
    }

    /*
     * Process one node.
     */
    dns_dbiterator_pause(nsec3chain->dbiterator);
    result = dns_nsec3_addnsec3(
      db, version, name, &nsec3chain->nsec3param,
      zone_nsecttl(zone), unsecure, &nsec3_diff);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_nsec3chain:"
           "dns_nsec3_addnsec3 -> %s",
           isc_result_totext(result));
      goto cleanup;
    }

    /*
     * Treat each call to dns_nsec3_addnsec3() as if it's cost is
     * two signatures.  Additionally there will, in general, be
     * two signature generated below.
     *
     * If we are only changing the optout flag the cost is half
     * that of the cost of generating a completely new chain.
     */
    signatures -= 4;

    /*
     * Go onto next node.
     */
  next_addnode:
    first = false;
    dns_db_detachnode(&node);
    do {
      result = dns_dbiterator_next(nsec3chain->dbiterator);

      if (result == ISC_R_NOMORE && nsec3chain->delete_nsec) {
        dns_dbiterator_pause(nsec3chain->dbiterator);
        CHECK(fixup_nsec3param(db, version, nsec3chain,
                   false, privatetype,
                   &param_diff));
        LOCK_ZONE(zone);
        ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain,
            link);
        UNLOCK_ZONE(zone);
        ISC_LIST_APPEND(cleanup, nsec3chain, link);
        goto next_addchain;
      }
      if (result == ISC_R_NOMORE) {
        dns_dbiterator_pause(nsec3chain->dbiterator);
        if (nsec3chain->seen_nsec) {
          CHECK(fixup_nsec3param(
            db, version, nsec3chain, true,
            privatetype, &param_diff));
          nsec3chain->delete_nsec = true;
          goto same_addchain;
        }
        CHECK(fixup_nsec3param(db, version, nsec3chain,
                   false, privatetype,
                   &param_diff));
        LOCK_ZONE(zone);
        ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain,
            link);
        UNLOCK_ZONE(zone);
        ISC_LIST_APPEND(cleanup, nsec3chain, link);
        goto next_addchain;
      } else if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_nsec3chain:"
             "dns_dbiterator_next -> %s",
             isc_result_totext(result));
        goto cleanup;
      } else if (delegation) {
        dns_dbiterator_current(nsec3chain->dbiterator,
                   &node, nextname);
        dns_db_detachnode(&node);
        if (!dns_name_issubdomain(nextname, name)) {
          break;
        }
      } else {
        break;
      }
    } while (1);
    continue;

  same_addchain:
    CHECK(dns_dbiterator_first(nsec3chain->dbiterator));
    first = true;
    continue;

  next_addchain:
    dns_dbiterator_pause(nsec3chain->dbiterator);
    nsec3chain = nextnsec3chain;
    first = true;
    if (nsec3chain != NULL) {
      nsec3chain->save_delete_nsec = nsec3chain->delete_nsec;
    }
  }

  if (nsec3chain != NULL) {
    goto skip_removals;
  }

  /*
   * Process removals.
   *
   * This is a counterpart of the above while loop which takes care of
   * removing an NSEC3 chain.  It starts with determining whether the
   * zone needs to switch from NSEC3 to NSEC; if so, it first builds an
   * NSEC chain by iterating over all nodes in the zone database and only
   * then goes on to remove NSEC3 records be iterating over all nodes
   * again and calling deletematchingnsec3() for each of them; otherwise,
   * it starts removing NSEC3 records immediately.  Rules for processing
   * obscured nodes and interrupting work are the same as for the while
   * loop above.
   */
  LOCK_ZONE(zone);
  nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
  UNLOCK_ZONE(zone);
  first = true;
  buildnsecchain = false;
  while (nsec3chain != NULL && nodes-- > 0 && signatures > 0) {
    dns_dbiterator_pause(nsec3chain->dbiterator);

    LOCK_ZONE(zone);
    dns_nsec3chain_t *nextnsec3chain = ISC_LIST_NEXT(nsec3chain,
                 link);
    UNLOCK_ZONE(zone);

    if (nsec3chain->db != db) {
      goto next_removechain;
    }

    if (!NSEC3REMOVE(nsec3chain->nsec3param.flags)) {
      goto next_removechain;
    }

    /*
     * Work out if we need to build a NSEC chain as a consequence
     * of removing this NSEC3 chain.
     */
    if (first && !updatensec &&
        (nsec3chain->nsec3param.flags & DNS_NSEC3FLAG_NONSEC) == 0)
    {
      result = need_nsec_chain(db, version,
             &nsec3chain->nsec3param,
             &buildnsecchain);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_nsec3chain:"
             "need_nsec_chain -> %s",
             isc_result_totext(result));
        goto cleanup;
      }
    }

    if (first) {
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "zone_nsec3chain:buildnsecchain = %u",
           buildnsecchain);
    }

    dns_dbiterator_current(nsec3chain->dbiterator, &node, name);
    dns_dbiterator_pause(nsec3chain->dbiterator);
    delegation = false;

    if (!buildnsecchain) {
      /*
       * Delete the NSEC3PARAM record matching this chain.
       */
      if (first) {
        result = fixup_nsec3param(
          db, version, nsec3chain, true,
          privatetype, &param_diff);
        if (result != ISC_R_SUCCESS) {
          dnssec_log(zone, ISC_LOG_ERROR,
               "zone_nsec3chain:"
               "fixup_nsec3param -> %s",
               isc_result_totext(result));
          goto cleanup;
        }
      }

      /*
       * Delete the NSEC3 records.
       */
      result = deletematchingnsec3(db, version, node, name,
                 &nsec3chain->nsec3param,
                 &nsec3_diff);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_nsec3chain:"
             "deletematchingnsec3 -> %s",
             isc_result_totext(result));
        goto cleanup;
      }
      goto next_removenode;
    }

    if (first) {
      dns_fixedname_t ffound;
      dns_name_t *found;
      found = dns_fixedname_initname(&ffound);
      result = dns_db_find(
        db, name, version, dns_rdatatype_soa,
        DNS_DBFIND_NOWILD, 0, found, NULL, NULL);
      if ((result == DNS_R_DELEGATION ||
           result == DNS_R_DNAME) &&
          !dns_name_equal(name, found))
      {
        /*
         * Remember the obscuring name so that
         * we skip all obscured names.
         */
        dns_name_copy(found, name);
        delegation = true;
        goto next_removenode;
      }
    }

    /*
     * Check to see if this is a bottom of zone node.
     */
    result = allrdatasets(db, node, version, &iterator, &seen);
    if (result == ISC_R_NOTFOUND) {
      /* Empty node? */
      goto next_removenode;
    }
    CHECK(result);

    dns_rdatasetiter_destroy(&iterator);

    if (!seen.rr || seen.nsec3 || seen.nsec) {
      goto next_removenode;
    }
    if ((seen.ns && !seen.soa) || seen.dname) {
      delegation = true;
    }

    /*
     * Add a NSEC record except at the origin.
     */
    if (!dns_name_equal(name, dns_db_origin(db))) {
      dns_dbiterator_pause(nsec3chain->dbiterator);
      CHECK(add_nsec(db, version, name, node,
               zone_nsecttl(zone), delegation,
               &nsec_diff));
      signatures--;
    }

  next_removenode:
    first = false;
    dns_db_detachnode(&node);
    do {
      result = dns_dbiterator_next(nsec3chain->dbiterator);
      if (result == ISC_R_NOMORE && buildnsecchain) {
        /*
         * The NSEC chain should now be built.
         * We can now remove the NSEC3 chain.
         */
        updatensec = true;
        goto same_removechain;
      }
      if (result == ISC_R_NOMORE) {
        dns_dbiterator_pause(nsec3chain->dbiterator);
        LOCK_ZONE(zone);
        ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain,
            link);
        UNLOCK_ZONE(zone);
        ISC_LIST_APPEND(cleanup, nsec3chain, link);
        result = fixup_nsec3param(
          db, version, nsec3chain, false,
          privatetype, &param_diff);
        if (result != ISC_R_SUCCESS) {
          dnssec_log(zone, ISC_LOG_ERROR,
               "zone_nsec3chain:"
               "fixup_nsec3param -> %s",
               isc_result_totext(result));
          goto cleanup;
        }
        goto next_removechain;
      } else if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_nsec3chain:"
             "dns_dbiterator_next -> %s",
             isc_result_totext(result));
        goto cleanup;
      } else if (delegation) {
        dns_dbiterator_current(nsec3chain->dbiterator,
                   &node, nextname);
        dns_db_detachnode(&node);
        if (!dns_name_issubdomain(nextname, name)) {
          break;
        }
      } else {
        break;
      }
    } while (1);
    continue;

  same_removechain:
    CHECK(dns_dbiterator_first(nsec3chain->dbiterator));
    buildnsecchain = false;
    first = true;
    continue;

  next_removechain:
    dns_dbiterator_pause(nsec3chain->dbiterator);
    nsec3chain = nextnsec3chain;
    first = true;
  }

skip_removals:
  /*
   * We may need to update the NSEC/NSEC3 records for the zone apex.
   */
  if (!ISC_LIST_EMPTY(param_diff.tuples)) {
    bool rebuild_nsec = false, rebuild_nsec3 = false;
    result = dns_db_getoriginnode(db, &node);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    result = dns_db_allrdatasets(db, node, version, 0, 0,
               &iterator);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_nsec3chain:dns_db_allrdatasets -> %s",
           isc_result_totext(result));
      goto cleanup;
    }
    DNS_RDATASETITER_FOREACH(iterator) {
      dns_rdataset_t rdataset = DNS_RDATASET_INIT;
      dns_rdatasetiter_current(iterator, &rdataset);
      if (rdataset.type == dns_rdatatype_nsec) {
        rebuild_nsec = true;
      } else if (rdataset.type == dns_rdatatype_nsec3param) {
        rebuild_nsec3 = true;
      }
      dns_rdataset_disassociate(&rdataset);
    }
    dns_rdatasetiter_destroy(&iterator);
    dns_db_detachnode(&node);

    if (rebuild_nsec) {
      if (nsec3chain != NULL) {
        dns_dbiterator_pause(nsec3chain->dbiterator);
      }

      result = updatesecure(db, version, &zone->origin,
                zone_nsecttl(zone), true,
                &nsec_diff);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_nsec3chain:updatesecure -> %s",
             isc_result_totext(result));
        goto cleanup;
      }
    }

    if (rebuild_nsec3) {
      if (nsec3chain != NULL) {
        dns_dbiterator_pause(nsec3chain->dbiterator);
      }

      result = dns_nsec3_addnsec3s(
        db, version, dns_db_origin(db),
        zone_nsecttl(zone), false, &nsec3_diff);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_nsec3chain:"
             "dns_nsec3_addnsec3s -> %s",
             isc_result_totext(result));
        goto cleanup;
      }
    }
  }

  /*
   * Add / update signatures for the NSEC3 records.
   */
  if (nsec3chain != NULL) {
    dns_dbiterator_pause(nsec3chain->dbiterator);
  }
  result = dns__zone_updatesigs(&nsec3_diff, db, version, zone_keys,
              nkeys, zone, inception, expire, 0, now,
              &zonediff);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:dns__zone_updatesigs -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  /*
   * We have changed the NSEC3PARAM or private RRsets
   * above so we need to update the signatures.
   */
  result = dns__zone_updatesigs(&param_diff, db, version, zone_keys,
              nkeys, zone, inception, expire, 0, now,
              &zonediff);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:dns__zone_updatesigs -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  if (updatensec) {
    result = updatesecure(db, version, &zone->origin,
              zone_nsecttl(zone), false, &nsec_diff);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_nsec3chain:updatesecure -> %s",
           isc_result_totext(result));
      goto cleanup;
    }
  }

  result = dns__zone_updatesigs(&nsec_diff, db, version, zone_keys, nkeys,
              zone, inception, expire, 0, now,
              &zonediff);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:dns__zone_updatesigs -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  /*
   * If we made no effective changes to the zone then we can just
   * cleanup otherwise we need to increment the serial.
   */
  if (ISC_LIST_EMPTY(zonediff.diff->tuples)) {
    /*
     * No need to call dns_db_closeversion() here as it is
     * called with commit = true below.
     */
    goto closeversion;
  }

  result = del_sigs(zone, db, version, &zone->origin, dns_rdatatype_soa,
        &zonediff, zone_keys, nkeys, now, false);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:del_sigs -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  result = update_soa_serial(zone, db, version, zonediff.diff, zone->mctx,
           zone->updatemethod);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:update_soa_serial -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  result = add_sigs(db, version, &zone->origin, zone, dns_rdatatype_soa,
        zonediff.diff, zone_keys, nkeys, zone->mctx, now,
        inception, soaexpire);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_nsec3chain:add_sigs -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  /* Write changes to journal file. */
  CHECK(zone_journal(zone, zonediff.diff, NULL, "zone_nsec3chain"));

  LOCK_ZONE(zone);
  zone_needdump(zone, DNS_DUMP_DELAY);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
  UNLOCK_ZONE(zone);

closeversion:
  /*
   * Pause all iterators so that dns_db_closeversion() can succeed.
   */
  LOCK_ZONE(zone);
  ISC_LIST_FOREACH(zone->nsec3chain, chain, link) {
    dns_dbiterator_pause(chain->dbiterator);
  }
  UNLOCK_ZONE(zone);

  /*
   * Everything has succeeded. Commit the changes.
   * Unconditionally commit as zonediff.offline not checked above.
   */
  dns_db_closeversion(db, &version, true);

  /*
   * Everything succeeded so we can clean these up now.
   */
  ISC_LIST_FOREACH(cleanup, chain, link) {
    ISC_LIST_UNLINK(cleanup, chain, link);
    dns_db_detach(&chain->db);
    dns_dbiterator_destroy(&chain->dbiterator);
    isc_mem_put(zone->mctx, chain, sizeof *chain);
  }

  LOCK_ZONE(zone);
  dns__zone_set_resigntime(zone);
  UNLOCK_ZONE(zone);

cleanup:
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR, "zone_nsec3chain: %s",
         isc_result_totext(result));
  }

  /*
   * On error roll back the current nsec3chain.
   */
  if (result != ISC_R_SUCCESS && nsec3chain != NULL) {
    if (nsec3chain->done) {
      dns_db_detach(&nsec3chain->db);
      dns_dbiterator_destroy(&nsec3chain->dbiterator);
      isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
    } else {
      result = dns_dbiterator_first(nsec3chain->dbiterator);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      dns_dbiterator_pause(nsec3chain->dbiterator);
      nsec3chain->delete_nsec = nsec3chain->save_delete_nsec;
    }
  }

  /*
   * Rollback the cleanup list.
   */
  ISC_LIST_FOREACH_REV(cleanup, chain, link) {
    ISC_LIST_UNLINK(cleanup, chain, link);
    if (chain->done) {
      dns_db_detach(&chain->db);
      dns_dbiterator_destroy(&chain->dbiterator);
      isc_mem_put(zone->mctx, chain, sizeof *chain);
    } else {
      LOCK_ZONE(zone);
      ISC_LIST_PREPEND(zone->nsec3chain, chain, link);
      UNLOCK_ZONE(zone);
      result = dns_dbiterator_first(chain->dbiterator);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      dns_dbiterator_pause(chain->dbiterator);
      chain->delete_nsec = chain->save_delete_nsec;
    }
  }

  LOCK_ZONE(zone);
  ISC_LIST_FOREACH(zone->nsec3chain, chain, link) {
    dns_dbiterator_pause(chain->dbiterator);
  }
  UNLOCK_ZONE(zone);

  dns_diff_clear(&param_diff);
  dns_diff_clear(&nsec3_diff);
  dns_diff_clear(&nsec_diff);
  dns_diff_clear(&_sig_diff);

  if (iterator != NULL) {
    dns_rdatasetiter_destroy(&iterator);
  }

  for (i = 0; i < nkeys; i++) {
    dst_key_free(&zone_keys[i]);
  }

  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
    dns_db_detach(&db);
  } else if (db != NULL) {
    dns_db_detach(&db);
  }

  LOCK_ZONE(zone);
  if (ISC_LIST_HEAD(zone->nsec3chain) != NULL) {
    isc_interval_t interval;
    if (zone->update_disabled || result != ISC_R_SUCCESS) {
      isc_interval_set(&interval, 60, 0); /* 1 minute */
    } else {
      isc_interval_set(&interval, 0, 10000000); /* 10 ms */
    }
    isc_time_nowplusinterval(&zone->nsec3chaintime, &interval);
  } else {
    isc_time_settoepoch(&zone->nsec3chaintime);
  }
  UNLOCK_ZONE(zone);

  INSIST(version == NULL);
}

/*%
 * Delete all RRSIG records with the given algorithm and keyid.
 * Remove the NSEC record and RRSIGs if nkeys is zero.
 * If all remaining RRsets are signed with the given algorithm
 * set *has_algp to true.
 */
static isc_result_t
del_sig(dns_db_t *db, dns_dbversion_t *version, dns_name_t *name,
  dns_dbnode_t *node, unsigned int nkeys, dst_algorithm_t algorithm,
  uint16_t keyid, bool *has_algp, dns_diff_t *diff) {
  dns_rdata_rrsig_t rrsig;
  dns_rdataset_t rdataset;
  dns_rdatasetiter_t *iterator = NULL;
  isc_result_t result;
  bool alg_missed = false;
  bool alg_found = false;

  char namebuf[DNS_NAME_FORMATSIZE];
  dns_name_format(name, namebuf, sizeof(namebuf));

  result = dns_db_allrdatasets(db, node, version, 0, 0, &iterator);
  if (result != ISC_R_SUCCESS) {
    if (result == ISC_R_NOTFOUND) {
      result = ISC_R_SUCCESS;
    }
    return result;
  }

  dns_rdataset_init(&rdataset);
  DNS_RDATASETITER_FOREACH(iterator) {
    bool has_alg = false;
    dns_rdatasetiter_current(iterator, &rdataset);
    if (nkeys == 0 && rdataset.type == dns_rdatatype_nsec) {
      DNS_RDATASET_FOREACH(&rdataset) {
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdataset_current(&rdataset, &rdata);
        CHECK(update_one_rr(db, version, diff,
                DNS_DIFFOP_DEL, name,
                rdataset.ttl, &rdata));
      }
      dns_rdataset_disassociate(&rdataset);
      continue;
    }
    if (rdataset.type != dns_rdatatype_rrsig) {
      dns_rdataset_disassociate(&rdataset);
      continue;
    }
    DNS_RDATASET_FOREACH(&rdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dst_algorithm_t sigalg;

      dns_rdataset_current(&rdataset, &rdata);
      CHECK(dns_rdata_tostruct(&rdata, &rrsig));

      sigalg = dst_algorithm_fromdata(
        rrsig.algorithm, rrsig.signature, rrsig.siglen);
      if (nkeys != 0 &&
          (sigalg != algorithm || rrsig.keyid != keyid))
      {
        if (sigalg == algorithm) {
          has_alg = true;
        }
        continue;
      }
      CHECK(update_one_rr(db, version, diff,
              DNS_DIFFOP_DELRESIGN, name,
              rdataset.ttl, &rdata));
    }
    dns_rdataset_disassociate(&rdataset);

    /*
     * After deleting, if there's still a signature for
     * 'algorithm', set alg_found; if not, set alg_missed.
     */
    if (has_alg) {
      alg_found = true;
    } else {
      alg_missed = true;
    }
  }

  /*
   * Set `has_algp` if the algorithm was found in every RRset:
   * i.e., found in at least one, and not missing from any.
   */
  *has_algp = (alg_found && !alg_missed);
cleanup:
  dns_rdataset_cleanup(&rdataset);
  dns_rdatasetiter_destroy(&iterator);
  return result;
}

/*
 * Prevent the zone entering a inconsistent state where
 * NSEC only DNSKEYs are present with NSEC3 chains.
 */
bool
dns_zone_check_dnskey_nsec3(dns_zone_t *zone, dns_db_t *db,
          dns_dbversion_t *ver, dns_diff_t *diff,
          dst_key_t **keys, unsigned int numkeys) {
  uint8_t alg;
  dns_rdatatype_t privatetype;
  bool nseconly = false, nsec3 = false;
  isc_result_t result;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(db != NULL);

  privatetype = dns_zone_getprivatetype(zone);

  /* Scan the tuples for an NSEC-only DNSKEY */
  if (diff != NULL) {
    ISC_LIST_FOREACH(diff->tuples, tuple, link) {
      if (nseconly && nsec3) {
        break;
      }

      if (tuple->op != DNS_DIFFOP_ADD) {
        continue;
      }

      if (tuple->rdata.type == dns_rdatatype_nsec3param) {
        nsec3 = true;
      }

      if (tuple->rdata.type != dns_rdatatype_dnskey) {
        continue;
      }

      alg = tuple->rdata.data[3];
      if (alg == DNS_KEYALG_RSAMD5 || alg == DNS_KEYALG_DSA ||
          alg == DNS_KEYALG_RSASHA1)
      {
        nseconly = true;
      }
    }
  }
  /* Scan the zone keys for an NSEC-only DNSKEY */
  if (keys != NULL && !nseconly) {
    for (unsigned int i = 0; i < numkeys; i++) {
      alg = dst_key_alg(keys[i]);
      if (alg == DNS_KEYALG_RSAMD5 || alg == DNS_KEYALG_DSA ||
          alg == DNS_KEYALG_RSASHA1)
      {
        nseconly = true;
        break;
      }
    }
  }

  /* Check DB for NSEC-only DNSKEY */
  if (!nseconly) {
    result = dns_nsec_nseconly(db, ver, diff, &nseconly);
    /*
     * Adding an NSEC3PARAM record can proceed without a
     * DNSKEY (it will trigger a delayed change), so we can
     * ignore ISC_R_NOTFOUND here.
     */
    if (result == ISC_R_NOTFOUND) {
      result = ISC_R_SUCCESS;
    }
    CHECK(result);
  }

  /* Check existing DB for NSEC3 */
  if (!nsec3) {
    CHECK(dns_nsec3_activex(db, ver, false, privatetype, &nsec3));
  }

  /* Check kasp for NSEC3PARAM settings */
  if (!nsec3) {
    dns_kasp_t *kasp = zone->kasp;
    if (kasp != NULL) {
      nsec3 = dns_kasp_nsec3(kasp);
    }
  }

  /* Refuse to allow NSEC3 with NSEC-only keys */
  if (nseconly && nsec3) {
    goto cleanup;
  }

  return true;

cleanup:
  return false;
}

/*
 * Incrementally sign the zone using the keys requested.
 * Builds the NSEC chain if required.
 */
static void
zone_sign(dns_zone_t *zone) {
  dns_db_t *db = NULL;
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *version = NULL;
  dns_diff_t _sig_diff;
  dns_diff_t post_diff;
  dns__zonediff_t zonediff;
  dns_fixedname_t fixed;
  dns_fixedname_t nextfixed;
  dns_kasp_t *kasp = NULL;
  dns_name_t *name = NULL, *nextname = NULL;
  dns_rdataset_t rdataset;
  dns_signing_t *signing = NULL;
  dns_signinglist_t cleanup;
  dst_key_t *zone_keys[DNS_MAXZONEKEYS];
  int32_t signatures;
  bool is_ksk, is_zsk;
  bool with_ksk, with_zsk;
  bool commit = false;
  bool is_bottom_of_zone;
  bool build_nsec = false;
  bool build_nsec3 = false;
  bool use_kasp = false;
  bool first;
  isc_result_t result;
  isc_stdtime_t now, inception, soaexpire, expire;
  unsigned int i, j;
  unsigned int nkeys = 0;
  uint32_t nodes;

  ENTER;

  dns_rdataset_init(&rdataset);
  name = dns_fixedname_initname(&fixed);
  nextname = dns_fixedname_initname(&nextfixed);
  dns_diff_init(zone->mctx, &_sig_diff);
  dns_diff_init(zone->mctx, &post_diff);
  zonediff_init(&zonediff, &_sig_diff);
  ISC_LIST_INIT(cleanup);

  /*
   * Updates are disabled.  Pause for 1 minute.
   */
  if (zone->update_disabled) {
    result = ISC_R_FAILURE;
    goto done;
  }

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    result = ISC_R_FAILURE;
    goto done;
  }

  result = dns_db_newversion(db, &version);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_sign:dns_db_newversion -> %s",
         isc_result_totext(result));
    goto done;
  }

  now = isc_stdtime_now();

  result = dns_zone_findkeys(zone, db, version, now, zone->mctx,
           DNS_MAXZONEKEYS, zone_keys, &nkeys);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_sign:dns_zone_findkeys -> %s",
         isc_result_totext(result));
    goto done;
  }

  kasp = zone->kasp;

  calculate_rrsig_validity(zone, now, &inception, &soaexpire, NULL,
         &expire);

  /*
   * We keep pulling nodes off each iterator in turn until
   * we have no more nodes to pull off or we reach the limits
   * for this quantum.
   */
  nodes = zone->nodes;
  signatures = zone->signatures;
  signing = ISC_LIST_HEAD(zone->signing);
  first = true;

  if (kasp != NULL) {
    use_kasp = true;
  }
  dnssec_log(zone, ISC_LOG_DEBUG(3), "zone_sign:use kasp -> %s",
       use_kasp ? "yes" : "no");

  /* Determine which type of chain to build */
  CHECK(dns_private_chains(db, version, zone->privatetype, &build_nsec,
         &build_nsec3));
  if (!build_nsec && !build_nsec3) {
    if (use_kasp) {
      build_nsec3 = dns_kasp_nsec3(kasp);
      if (!dns_zone_check_dnskey_nsec3(
            zone, db, version, NULL,
            (dst_key_t **)&zone_keys, nkeys))
      {
        dnssec_log(zone, ISC_LOG_INFO,
             "wait building NSEC3 chain until "
             "NSEC only DNSKEYs are removed");
        build_nsec3 = false;
      }
      build_nsec = !build_nsec3;
    } else {
      /* If neither chain is found, default to NSEC */
      build_nsec = true;
    }
  }

  while (signing != NULL && nodes-- > 0 && signatures > 0) {
    dns_signing_t *nextsigning = ISC_LIST_NEXT(signing, link);
    bool has_alg = false;
    bool have_adt = false;

    dns_dbiterator_pause(signing->dbiterator);

    ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
    if (signing->done || signing->db != zone->db) {
      /*
       * The zone has been reloaded.  We will have to
       * created new signings as part of the reload
       * process so we can destroy this one.
       */
      ISC_LIST_UNLINK(zone->signing, signing, link);
      ISC_LIST_APPEND(cleanup, signing, link);
      ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
      goto next_signing;
    }
    ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

    if (signing->db != db) {
      goto next_signing;
    }

    is_bottom_of_zone = false;

    if (first && signing->deleteit) {
      /*
       * Remove the key we are deleting from consideration.
       */
      for (i = 0, j = 0; i < nkeys; i++) {
        /*
         * Find the key we want to remove.
         */
        if (ALG(zone_keys[i]) == signing->algorithm &&
            dst_key_id(zone_keys[i]) == signing->keyid)
        {
          dst_key_free(&zone_keys[i]);
          continue;
        }
        zone_keys[j] = zone_keys[i];
        j++;
      }
      for (i = j; i < nkeys; i++) {
        zone_keys[i] = NULL;
      }
      nkeys = j;
    }

    dns_dbiterator_current(signing->dbiterator, &node, name);

    if (signing->deleteit) {
      dns_dbiterator_pause(signing->dbiterator);
      CHECK(del_sig(db, version, name, node, nkeys,
              signing->algorithm, signing->keyid,
              &has_alg, zonediff.diff));
    }

    /*
     * On the first pass we need to check if the current node
     * has not been obscured.
     */
    if (first) {
      dns_fixedname_t ffound;
      dns_name_t *found;
      found = dns_fixedname_initname(&ffound);
      result = dns_db_find(
        db, name, version, dns_rdatatype_soa,
        DNS_DBFIND_NOWILD, 0, found, NULL, NULL);
      if ((result == DNS_R_DELEGATION ||
           result == DNS_R_DNAME) &&
          !dns_name_equal(name, found))
      {
        /*
         * Remember the obscuring name so that
         * we skip all obscured names.
         */
        dns_name_copy(found, name);
        is_bottom_of_zone = true;
        goto next_node;
      }
    }

    /* Check whether we still have any ADT keys */
    for (i = 0; i < nkeys; i++) {
      if (ADT(zone_keys[i])) {
        have_adt = true;
        break;
      }
    }

    /*
     * Process one node.
     */
    with_ksk = false;
    with_zsk = false;
    dns_dbiterator_pause(signing->dbiterator);

    CHECK(check_if_bottom_of_zone(db, node, version,
                &is_bottom_of_zone));

    for (i = 0; !has_alg && i < nkeys; i++) {
      bool both = false;
      /*
       * Find the keys we want to sign with.
       */
      if (!dst_key_isprivate(zone_keys[i])) {
        continue;
      }
      if (dst_key_inactive(zone_keys[i])) {
        continue;
      }

      /*
       * When adding look for the specific key.
       */
      if (!signing->deleteit &&
          (ALG(zone_keys[i]) != signing->algorithm ||
           dst_key_id(zone_keys[i]) != signing->keyid))
      {
        continue;
      }

      /*
       * When deleting make sure we are properly signed
       * with the algorithm that was being removed.
       */
      if (signing->deleteit &&
          ALG(zone_keys[i]) != signing->algorithm)
      {
        continue;
      }

      /*
       * We do KSK processing.
       */
      if (use_kasp) {
        /*
         * A dnssec-policy is found. Check what
         * RRsets this key can sign.
         */
        isc_result_t kresult;
        is_ksk = false;
        kresult = dst_key_getbool(
          zone_keys[i], DST_BOOL_KSK, &is_ksk);
        if (kresult != ISC_R_SUCCESS) {
          if (KSK(zone_keys[i])) {
            is_ksk = true;
          }
        }

        is_zsk = false;
        kresult = dst_key_getbool(
          zone_keys[i], DST_BOOL_ZSK, &is_zsk);
        if (kresult != ISC_R_SUCCESS) {
          if (!KSK(zone_keys[i])) {
            is_zsk = true;
          }
        }
        both = true;
      } else {
        is_ksk = KSK(zone_keys[i]);
        is_zsk = !is_ksk;

        /*
         * Don't consider inactive keys, however the key
         * may be temporary offline, so do consider KSKs
         * which private key files are unavailable.
         */
        both = dst_key_have_ksk_and_zsk(
          zone_keys, nkeys, i, false, is_ksk,
          is_zsk, NULL, NULL);
        if (both || REVOKE(zone_keys[i])) {
          is_ksk = KSK(zone_keys[i]);
          is_zsk = !KSK(zone_keys[i]);
        } else {
          is_ksk = false;
          is_zsk = false;
        }
      }

      /*
       * If deleting signatures, we need to ensure that
       * the RRset is still signed at least once by a
       * KSK and a ZSK.
       */
      if (signing->deleteit && is_zsk && with_zsk) {
        continue;
      }

      if (signing->deleteit && is_ksk && with_ksk) {
        continue;
      }

      CHECK(sign_a_node(
        db, zone, name, node, version, build_nsec3,
        build_nsec, zone_keys[i], now, inception,
        expire, zone_nsecttl(zone), both, is_ksk,
        is_zsk, signing->fullsign, is_bottom_of_zone,
        have_adt, zonediff.diff, &signatures,
        zone->mctx));
      /*
       * If we are adding we are done.  Look for other keys
       * of the same algorithm if deleting.
       */
      if (!signing->deleteit) {
        break;
      }
      if (is_zsk) {
        with_zsk = true;
      }
      if (is_ksk) {
        with_ksk = true;
      }
    }

    /*
     * Go onto next node.
     */
  next_node:
    first = false;
    dns_db_detachnode(&node);
    do {
      result = dns_dbiterator_next(signing->dbiterator);
      if (result == ISC_R_NOMORE) {
        ISC_LIST_UNLINK(zone->signing, signing, link);
        ISC_LIST_APPEND(cleanup, signing, link);
        dns_dbiterator_pause(signing->dbiterator);
        if (nkeys != 0 && build_nsec) {
          /*
           * We have finished regenerating the
           * zone with a zone signing key.
           * The NSEC chain is now complete and
           * there is a full set of signatures
           * for the zone.  We can now clear the
           * OPT bit from the NSEC record.
           */
          result = updatesecure(
            db, version, &zone->origin,
            zone_nsecttl(zone), false,
            &post_diff);
          if (result != ISC_R_SUCCESS) {
            dnssec_log(zone, ISC_LOG_ERROR,
                 "updatesecure -> %s",
                 isc_result_totext(
                   result));
            goto done;
          }
        }
        result = updatesignwithkey(
          zone, signing, version, build_nsec3,
          zone_nsecttl(zone), &post_diff);
        if (result != ISC_R_SUCCESS) {
          dnssec_log(zone, ISC_LOG_ERROR,
               "updatesignwithkey -> %s",
               isc_result_totext(result));
          goto done;
        }
        build_nsec = false;
        goto next_signing;
      } else if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_sign:"
             "dns_dbiterator_next -> %s",
             isc_result_totext(result));
        goto done;
      } else if (is_bottom_of_zone) {
        dns_dbiterator_current(signing->dbiterator,
                   &node, nextname);
        dns_db_detachnode(&node);
        if (!dns_name_issubdomain(nextname, name)) {
          break;
        }
      } else {
        break;
      }
    } while (1);
    continue;

  next_signing:
    dns_dbiterator_pause(signing->dbiterator);
    signing = nextsigning;
    first = true;
  }

  if (ISC_LIST_HEAD(post_diff.tuples) != NULL) {
    result = dns__zone_updatesigs(&post_diff, db, version,
                zone_keys, nkeys, zone, inception,
                expire, 0, now, &zonediff);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_sign:dns__zone_updatesigs -> %s",
           isc_result_totext(result));
      goto done;
    }
  }

  /*
   * Have we changed anything?
   */
  if (ISC_LIST_EMPTY(zonediff.diff->tuples)) {
    if (zonediff.offline) {
      commit = true;
    }
    result = ISC_R_SUCCESS;
    goto pauseall;
  }

  commit = true;

  result = del_sigs(zone, db, version, &zone->origin, dns_rdatatype_soa,
        &zonediff, zone_keys, nkeys, now, false);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR, "zone_sign:del_sigs -> %s",
         isc_result_totext(result));
    goto done;
  }

  result = update_soa_serial(zone, db, version, zonediff.diff, zone->mctx,
           zone->updatemethod);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "zone_sign:update_soa_serial -> %s",
         isc_result_totext(result));
    goto done;
  }

  /*
   * Generate maximum life time signatures so that the above loop
   * termination is sensible.
   */
  result = add_sigs(db, version, &zone->origin, zone, dns_rdatatype_soa,
        zonediff.diff, zone_keys, nkeys, zone->mctx, now,
        inception, soaexpire);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR, "zone_sign:add_sigs -> %s",
         isc_result_totext(result));
    goto done;
  }

  /*
   * Write changes to journal file.
   */
  CHECK(zone_journal(zone, zonediff.diff, NULL, "zone_sign"));

pauseall:
  /*
   * Pause all iterators so that dns_db_closeversion() can succeed.
   */
  ISC_LIST_FOREACH(zone->signing, s, link) {
    dns_dbiterator_pause(s->dbiterator);
  }

  ISC_LIST_FOREACH(cleanup, s, link) {
    dns_dbiterator_pause(s->dbiterator);
  }

  /*
   * Everything has succeeded. Commit the changes.
   */
  dns_db_closeversion(db, &version, commit);

  /*
   * Everything succeeded so we can clean these up now.
   */
  ISC_LIST_FOREACH(cleanup, s, link) {
    ISC_LIST_UNLINK(cleanup, s, link);
    dns_db_detach(&s->db);
    dns_dbiterator_destroy(&s->dbiterator);
    isc_mem_put(zone->mctx, s, sizeof *s);
  }

  LOCK_ZONE(zone);
  dns__zone_set_resigntime(zone);
  if (commit) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
    zone_needdump(zone, DNS_DUMP_DELAY);
  }
  UNLOCK_ZONE(zone);

cleanup:
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR, "zone_sign: failed: %s",
         isc_result_totext(result));
  }

done:
  /*
   * Pause all dbiterators.
   */
  ISC_LIST_FOREACH(zone->signing, s, link) {
    dns_dbiterator_pause(s->dbiterator);
  }

  /*
   * Rollback the cleanup list.
   */
  ISC_LIST_FOREACH(cleanup, s, link) {
    ISC_LIST_UNLINK(cleanup, s, link);
    ISC_LIST_PREPEND(zone->signing, s, link);
    dns_dbiterator_first(s->dbiterator);
    dns_dbiterator_pause(s->dbiterator);
  }

  dns_diff_clear(&_sig_diff);
  dns_diff_clear(&post_diff);

  for (i = 0; i < nkeys; i++) {
    dst_key_free(&zone_keys[i]);
  }

  if (node != NULL) {
    dns_db_detachnode(&node);
  }

  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
    dns_db_detach(&db);
  } else if (db != NULL) {
    dns_db_detach(&db);
  }

  LOCK_ZONE(zone);
  if (ISC_LIST_HEAD(zone->signing) != NULL) {
    isc_interval_t interval;
    if (zone->update_disabled || result != ISC_R_SUCCESS) {
      isc_interval_set(&interval, 60, 0); /* 1 minute */
    } else {
      isc_interval_set(&interval, 0, 10000000); /* 10 ms */
    }
    isc_time_nowplusinterval(&zone->signingtime, &interval);
  } else {
    isc_time_settoepoch(&zone->signingtime);
  }
  UNLOCK_ZONE(zone);

  INSIST(version == NULL);
}

static isc_result_t
normalize_key(dns_rdata_t *rr, dns_rdata_t *target, unsigned char *data,
        int size) {
  dns_rdata_dnskey_t dnskey;
  dns_rdata_keydata_t keydata;
  isc_buffer_t buf;
  isc_result_t result = ISC_R_SUCCESS;

  dns_rdata_reset(target);
  isc_buffer_init(&buf, data, size);

  switch (rr->type) {
  case dns_rdatatype_dnskey:
    result = dns_rdata_tostruct(rr, &dnskey);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    dnskey.flags &= ~DNS_KEYFLAG_REVOKE;
    result = dns_rdata_fromstruct(target, rr->rdclass,
                dns_rdatatype_dnskey, &dnskey,
                &buf);
    break;
  case dns_rdatatype_keydata:
    result = dns_rdata_tostruct(rr, &keydata);
    if (result == ISC_R_UNEXPECTEDEND) {
      return result;
    }
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    dns_keydata_todnskey(&keydata, &dnskey);
    result = dns_rdata_fromstruct(target, rr->rdclass,
                dns_rdatatype_dnskey, &dnskey,
                &buf);
    break;
  default:
    UNREACHABLE();
  }

  return result;
}

/*
 * 'rdset' contains either a DNSKEY rdataset from the zone apex, or
 * a KEYDATA rdataset from the key zone.
 *
 * 'rr' contains either a DNSKEY record, or a KEYDATA record
 *
 * After normalizing keys to the same format (DNSKEY, with revoke bit
 * cleared), return true if a key that matches 'rr' is found in
 * 'rdset', or false if not.
 */

static bool
matchkey(dns_rdataset_t *rdset, dns_rdata_t *rr) {
  unsigned char data1[4096];
  dns_rdata_t rdata1 = DNS_RDATA_INIT;
  isc_result_t result;

  result = normalize_key(rr, &rdata1, data1, sizeof(data1));
  if (result != ISC_R_SUCCESS) {
    return false;
  }

  DNS_RDATASET_FOREACH(rdset) {
    unsigned char data2[4096];
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_t rdata2 = DNS_RDATA_INIT;

    dns_rdataset_current(rdset, &rdata);
    result = normalize_key(&rdata, &rdata2, data2, sizeof(data2));
    if (result != ISC_R_SUCCESS) {
      continue;
    }
    if (dns_rdata_compare(&rdata1, &rdata2) == 0) {
      return true;
    }
  }

  return false;
}

/*
 * Calculate the refresh interval for a keydata zone, per
 * RFC5011: MAX(1 hr,
 *    MIN(15 days,
 *        1/2 * OrigTTL,
 *        1/2 * RRSigExpirationInterval))
 * or for retries: MAX(1 hr,
 *           MIN(1 day,
 *         1/10 * OrigTTL,
 *         1/10 * RRSigExpirationInterval))
 */
static isc_stdtime_t
refresh_time(dns_zonefetch_t *fetch, bool retry) {
  isc_result_t result;
  uint32_t t;
  dns_rdataset_t *sigset;
  dns_rdata_t sigrr = DNS_RDATA_INIT;
  dns_rdata_rrsig_t sig;
  isc_stdtime_t now;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);

  now = isc_stdtime_now();

  if (dns_rdataset_isassociated(&fetch->sigset)) {
    sigset = &fetch->sigset;
  } else {
    return now + dns_zone_mkey_hour;
  }

  result = dns_rdataset_first(sigset);
  if (result != ISC_R_SUCCESS) {
    return now + dns_zone_mkey_hour;
  }

  dns_rdataset_current(sigset, &sigrr);
  result = dns_rdata_tostruct(&sigrr, &sig);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  if (!retry) {
    t = sig.originalttl / 2;

    if (isc_serial_gt(sig.timeexpire, now)) {
      uint32_t exp = (sig.timeexpire - now) / 2;
      if (t > exp) {
        t = exp;
      }
    }

    if (t > (15 * dns_zone_mkey_day)) {
      t = (15 * dns_zone_mkey_day);
    }

    if (t < dns_zone_mkey_hour) {
      t = dns_zone_mkey_hour;
    }
  } else {
    t = sig.originalttl / 10;

    if (isc_serial_gt(sig.timeexpire, now)) {
      uint32_t exp = (sig.timeexpire - now) / 10;
      if (t > exp) {
        t = exp;
      }
    }

    if (t > dns_zone_mkey_day) {
      t = dns_zone_mkey_day;
    }

    if (t < dns_zone_mkey_hour) {
      t = dns_zone_mkey_hour;
    }
  }

  return now + t;
}

/*
 * This routine is called when no changes are needed in a KEYDATA
 * record except to simply update the refresh timer.  Caller should
 * hold zone lock.
 */
static isc_result_t
minimal_update(dns_zonefetch_t *fetch, dns_dbversion_t *ver, dns_diff_t *diff) {
  dns_keyfetch_t *kfetch;
  isc_result_t result;
  isc_buffer_t keyb;
  unsigned char key_buf[4096];
  dns_rdata_keydata_t keydata;
  dns_name_t *name;
  dns_zone_t *zone;
  isc_stdtime_t now;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);

  now = isc_stdtime_now();
  zone = fetch->zone;
  name = dns_name(&fetch->name);
  kfetch = &fetch->fetchdata.keyfetch;

  DNS_RDATASET_FOREACH(&kfetch->keydataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&kfetch->keydataset, &rdata);

    /* Delete old version */
    CHECK(update_one_rr(kfetch->db, ver, diff, DNS_DIFFOP_DEL, name,
            0, &rdata));

    /* Update refresh timer */
    result = dns_rdata_tostruct(&rdata, &keydata);
    if (result == ISC_R_UNEXPECTEDEND) {
      continue;
    }
    CHECK(result);

    keydata.refresh = refresh_time(fetch, true);
    set_refreshkeytimer(zone, &keydata, now, false);

    dns_rdata_reset(&rdata);
    isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
    CHECK(dns_rdata_fromstruct(&rdata, zone->rdclass,
             dns_rdatatype_keydata, &keydata,
             &keyb));

    /* Insert updated version */
    CHECK(update_one_rr(kfetch->db, ver, diff, DNS_DIFFOP_ADD, name,
            0, &rdata));
  }
  result = ISC_R_SUCCESS;
cleanup:
  return result;
}

/*
 * Verify that DNSKEY set is signed by the key specified in 'keydata'.
 */
static bool
revocable(dns_zonefetch_t *fetch, dns_rdata_keydata_t *keydata) {
  isc_result_t result;
  dns_name_t *keyname;
  isc_mem_t *mctx;
  dns_rdata_t rr = DNS_RDATA_INIT;
  dns_rdata_rrsig_t sig;
  dns_rdata_dnskey_t dnskey;
  dst_key_t *dstkey = NULL;
  unsigned char key_buf[4096];
  isc_buffer_t keyb;
  bool answer = false;
  dst_algorithm_t algorithm;

  REQUIRE(fetch != NULL && keydata != NULL);
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);
  REQUIRE(dns_rdataset_isassociated(&fetch->sigset));

  keyname = dns_name(&fetch->name);
  mctx = fetch->zone->view->mctx;

  /* Generate a key from keydata */
  isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
  dns_keydata_todnskey(keydata, &dnskey);

  result = dns_rdata_fromstruct(&rr, keydata->common.rdclass,
              dns_rdatatype_dnskey, &dnskey, &keyb);
  if (result != ISC_R_SUCCESS) {
    return false;
  }

  result = dns_dnssec_keyfromrdata(keyname, &rr, mctx, &dstkey);
  if (result != ISC_R_SUCCESS) {
    return false;
  }

  /* See if that key generated any of the signatures */
  DNS_RDATASET_FOREACH(&fetch->sigset) {
    dns_rdata_t sigrr = DNS_RDATA_INIT;

    dns_rdataset_current(&fetch->sigset, &sigrr);
    result = dns_rdata_tostruct(&sigrr, &sig);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    algorithm = dst_algorithm_fromdata(sig.algorithm, sig.signature,
               sig.siglen);
    if (dst_key_alg(dstkey) == algorithm &&
        dst_key_rid(dstkey) == sig.keyid)
    {
      result = dns_dnssec_verify(keyname, &fetch->rrset,
               dstkey, false, mctx, &sigrr,
               NULL, NULL);

      dnssec_log(fetch->zone, ISC_LOG_DEBUG(3),
           "Confirm revoked DNSKEY is self-signed: %s",
           isc_result_totext(result));

      if (result == ISC_R_SUCCESS) {
        answer = true;
        break;
      }
    }
  }

  dst_key_free(&dstkey);
  return answer;
}

/*
 * Fetch DNSKEY records at the trust anchor name.
 */
static isc_result_t
keyfetch_start(dns_zonefetch_t *fetch) {
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);

  fetch->qname = dns_name(&fetch->name);
  fetch->qtype = dns_rdatatype_dnskey;

  return ISC_R_SUCCESS;
}

static void
keyfetch_continue(dns_zonefetch_t *fetch) {
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);
  /* No continue path for keyfetch exists. */
  REQUIRE(0);
}

static void
keyfetch_cancel(dns_zonefetch_t *fetch) {
  dns_keyfetch_t *kfetch;
  dns_zone_t *zone;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  kfetch = &fetch->fetchdata.keyfetch;
  zone = fetch->zone;

  /*
   * Error during a key fetch; cancel and retry in an hour.
   */
  zone->fetchcount[ZONEFETCHTYPE_KEY]--;

  dns_db_detach(&kfetch->db);
  dns_rdataset_disassociate(&kfetch->keydataset);

  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    /* Don't really retry if we are exiting */
    isc_time_t timenow, timethen;
    char timebuf[80];

    timenow = isc_time_now();
    DNS_ZONE_TIME_ADD(&timenow, dns_zone_mkey_hour, &timethen);
    zone->refreshkeytime = timethen;
    dns__zone_settimer(zone, timenow);

    isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
    dnssec_log(zone, ISC_LOG_DEBUG(1), "retry key refresh: %s",
         timebuf);
  }
}

static void
keyfetch_cleanup(dns_zonefetch_t *fetch) {
  dns_keyfetch_t *kfetch = NULL;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);

  kfetch = &fetch->fetchdata.keyfetch;

  dns_db_detach(&kfetch->db);

  dns_rdataset_cleanup(&kfetch->keydataset);
}

/*
 * A DNSKEY set has been fetched from the zone apex of a zone whose trust
 * anchors are being managed; scan the keyset, and update the key zone and the
 * local trust anchors according to RFC5011.
 */
static isc_result_t
keyfetch_done(dns_zonefetch_t *fetch, isc_result_t eresult) {
  isc_result_t result;
  dns_keyfetch_t *kfetch = NULL;
  dns_zone_t *zone = NULL;
  isc_mem_t *mctx = NULL;
  dns_keytable_t *secroots = NULL;
  dns_dbversion_t *ver = NULL;
  dns_diff_t diff;
  bool alldone = false;
  bool commit = false;
  dns_name_t *keyname = NULL;
  dns_rdata_t keydatarr = DNS_RDATA_INIT;
  dns_rdata_rrsig_t sig;
  dns_rdata_dnskey_t dnskey;
  dns_rdata_keydata_t keydata;
  bool initializing;
  char namebuf[DNS_NAME_FORMATSIZE];
  unsigned char key_buf[4096];
  isc_buffer_t keyb;
  dst_key_t *dstkey = NULL;
  isc_stdtime_t now;
  int pending = 0;
  bool secure = false, initial = false;
  dns_keynode_t *keynode = NULL;
  dns_rdataset_t *dnskeys = NULL, *dnskeysigs = NULL;
  dns_rdataset_t *keydataset = NULL, dsset;
  bool skipped[256] = { false };

  REQUIRE(fetch != NULL);
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_KEY);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  kfetch = &fetch->fetchdata.keyfetch;
  zone = fetch->zone;
  mctx = fetch->mctx;
  keyname = dns_name(&fetch->name);
  dnskeys = &fetch->rrset;
  dnskeysigs = &fetch->sigset;

  keydataset = &kfetch->keydataset;

  now = isc_stdtime_now();
  dns_name_format(keyname, namebuf, sizeof(namebuf));

  result = dns_view_getsecroots(zone->view, &secroots);
  INSIST(result == ISC_R_SUCCESS);

  dns_diff_init(mctx, &diff);

  CHECK(dns_db_newversion(kfetch->db, &ver));

  zone->fetchcount[ZONEFETCHTYPE_KEY]--;
  alldone = (zone->fetchcount[ZONEFETCHTYPE_KEY] == 0);

  if (alldone) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESHING);
  }

  dnssec_log(zone, ISC_LOG_DEBUG(3),
       "Returned from key fetch in keyfetch_done() for '%s': %s",
       namebuf, isc_result_totext(eresult));

  result = dns_zonefetch_verify(fetch, eresult, dns_trust_none);
  if (result != ISC_R_SUCCESS) {
    CHECK(minimal_update(fetch, ver, &diff));
    goto done;
  }

  /*
   * Clear any cached trust level, as we need to run validation
   * over again; trusted keys might have changed.
   */
  dnskeys->trust = dnskeysigs->trust = dns_trust_none;

  /* Look up the trust anchor */
  result = dns_keytable_find(secroots, keyname, &keynode);
  if (result != ISC_R_SUCCESS) {
    goto anchors_done;
  }

  /*
   * If the keynode has a DS trust anchor, use it for verification.
   */
  dns_rdataset_init(&dsset);
  if (dns_keynode_dsset(keynode, &dsset)) {
    DNS_RDATASET_FOREACH(dnskeysigs) {
      isc_result_t tresult = ISC_R_NOTFOUND;
      dns_rdata_t keyrdata = DNS_RDATA_INIT;
      dns_rdata_t sigrr = DNS_RDATA_INIT;

      dns_rdataset_current(dnskeysigs, &sigrr);
      dns_rdata_tostruct(&sigrr, &sig);

      DNS_RDATASET_FOREACH(&dsset) {
        dns_rdata_t dsrdata = DNS_RDATA_INIT;
        dns_rdata_ds_t ds;

        dns_rdata_reset(&dsrdata);
        dns_rdataset_current(&dsset, &dsrdata);
        dns_rdata_tostruct(&dsrdata, &ds);

        if (ds.key_tag != sig.keyid ||
            ds.algorithm != sig.algorithm)
        {
          continue;
        }

        tresult = dns_dnssec_matchdskey(
          keyname, &dsrdata, dnskeys, &keyrdata);
        if (tresult == ISC_R_SUCCESS) {
          break;
        }
      }

      if (tresult == ISC_R_NOTFOUND) {
        continue;
      }

      result = dns_dnssec_keyfromrdata(keyname, &keyrdata,
               mctx, &dstkey);
      if (result != ISC_R_SUCCESS) {
        continue;
      }

      result = dns_dnssec_verify(keyname, dnskeys, dstkey,
               false, mctx, &sigrr, NULL,
               NULL);
      dst_key_free(&dstkey);

      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "Verifying DNSKEY set for zone "
           "'%s' using DS %hu/%d: %s",
           namebuf, sig.keyid, sig.algorithm,
           isc_result_totext(result));

      if (result == ISC_R_SUCCESS) {
        dnskeys->trust = dns_trust_secure;
        dnskeysigs->trust = dns_trust_secure;
        initial = dns_keynode_initial(keynode);
        dns_keynode_trust(keynode);
        secure = true;
        break;
      }
    }
    dns_rdataset_disassociate(&dsset);
  }

anchors_done:
  if (keynode != NULL) {
    dns_keynode_detach(&keynode);
  }

  /*
   * If we were not able to verify the answer using the current
   * trusted keys then all we can do is look at any revoked keys.
   */
  if (!secure) {
    dnssec_log(zone, ISC_LOG_INFO,
         "DNSKEY set for zone '%s' could not be verified "
         "with current keys",
         namebuf);
  }

  /*
   * First scan keydataset to find keys that are not in dnskeyset
   *   - Missing keys which are not scheduled for removal,
   *     log a warning
   *   - Missing keys which are scheduled for removal and
   *     the remove hold-down timer has completed should
   *     be removed from the key zone
   *   - Missing keys whose acceptance timers have not yet
   *     completed, log a warning and reset the acceptance
   *     timer to 30 days in the future
   *   - All keys not being removed have their refresh timers
   *     updated
   */
  initializing = true;
  DNS_RDATASET_FOREACH(keydataset) {
    dns_keytag_t keytag;

    dns_rdata_reset(&keydatarr);
    dns_rdataset_current(keydataset, &keydatarr);
    result = dns_rdata_tostruct(&keydatarr, &keydata);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    dns_keydata_todnskey(&keydata, &dnskey);
    result = compute_tag(&dnskey, &keytag);
    if (result != ISC_R_SUCCESS) {
      /*
       * Skip if we cannot compute the key tag.
       * This may happen if the algorithm is unsupported
       */
      dns_zone_log(zone, ISC_LOG_ERROR,
             "Cannot compute tag for key in zone %s: "
             "%s (skipping)",
             namebuf, isc_result_totext(result));
      continue;
    }
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    /*
     * If any keydata record has a nonzero add holddown, then
     * there was a pre-existing trust anchor for this domain;
     * that means we are *not* initializing it and shouldn't
     * automatically trust all the keys we find at the zone apex.
     */
    initializing = initializing && (keydata.addhd == 0);

    if (!matchkey(dnskeys, &keydatarr)) {
      bool deletekey = false;

      if (!secure) {
        if (keydata.removehd != 0 &&
            keydata.removehd <= now)
        {
          deletekey = true;
        }
      } else if (keydata.addhd == 0) {
        deletekey = true;
      } else if (keydata.addhd > now) {
        dnssec_log(zone, ISC_LOG_INFO,
             "Pending key %hu for zone %s "
             "unexpectedly missing from DNSKEY "
             "RRset: restarting 30-day "
             "acceptance timer",
             keytag, namebuf);
        if (keydata.addhd < now + dns_zone_mkey_month) {
          keydata.addhd = now +
              dns_zone_mkey_month;
        }
        keydata.refresh = refresh_time(fetch, false);
      } else if (keydata.removehd == 0) {
        dnssec_log(zone, ISC_LOG_INFO,
             "Active key %hu for zone %s "
             "unexpectedly missing from DNSKEY "
             "RRset",
             keytag, namebuf);
        keydata.refresh = now + dns_zone_mkey_hour;
      } else if (keydata.removehd <= now) {
        deletekey = true;
        dnssec_log(
          zone, ISC_LOG_INFO,
          "Revoked key %hu for zone %s no longer "
          "present in DNSKEY RRset: deleting "
          "from managed keys database",
          keytag, namebuf);
      } else {
        keydata.refresh = refresh_time(fetch, false);
      }

      if (secure || deletekey) {
        /* Delete old version */
        CHECK(update_one_rr(kfetch->db, ver, &diff,
                DNS_DIFFOP_DEL, keyname, 0,
                &keydatarr));
      }

      if (!secure || deletekey) {
        continue;
      }

      dns_rdata_reset(&keydatarr);
      isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
      result = dns_rdata_fromstruct(&keydatarr, zone->rdclass,
                  dns_rdatatype_keydata,
                  &keydata, &keyb);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_WARNING,
             "dns_rdata_fromstruct failed: "
             "KEYDATA %hu: %s",
             keytag, isc_result_totext(result));
        continue;
      }

      /* Insert updated version */
      CHECK(update_one_rr(kfetch->db, ver, &diff,
              DNS_DIFFOP_ADD, keyname, 0,
              &keydatarr));

      set_refreshkeytimer(zone, &keydata, now, false);
    }
  }

  /*
   * Next scan dnskeyset:
   *   - If new keys are found (i.e., lacking a match in keydataset)
   *     add them to the key zone and set the acceptance timer
   *     to 30 days in the future (or to immediately if we've
   *     determined that we're initializing the zone for the
   *     first time)
   *   - Previously-known keys that have been revoked
   *     must be scheduled for removal from the key zone (or,
   *     if they hadn't been accepted as trust anchors yet
   *     anyway, removed at once)
   *   - Previously-known unrevoked keys whose acceptance timers
   *     have completed are promoted to trust anchors
   *   - All keys not being removed have their refresh
   *     timers updated
   */
  DNS_RDATASET_FOREACH(dnskeys) {
    dns_rdata_t dnskeyrr = DNS_RDATA_INIT;
    bool revoked = false;
    bool newkey = false;
    bool updatekey = false;
    bool deletekey = false;
    bool trustkey = false;
    dns_keytag_t keytag;

    dns_rdataset_current(dnskeys, &dnskeyrr);
    result = dns_rdata_tostruct(&dnskeyrr, &dnskey);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    /* Skip ZSK's */
    if ((dnskey.flags & DNS_KEYFLAG_KSK) == 0) {
      continue;
    }

    result = compute_tag(&dnskey, &keytag);
    if (result != ISC_R_SUCCESS) {
      /*
       * Skip if we cannot compute the key tag.
       * This may happen if the algorithm is unsupported
       */
      dns_zone_log(zone, ISC_LOG_ERROR,
             "Cannot compute tag for key in zone %s: "
             "%s (skipping)",
             namebuf, isc_result_totext(result));
      continue;
    }
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    if (!dns_resolver_algorithm_supported(
          zone->view->resolver, keyname, dnskey.algorithm,
          dnskey.data, dnskey.datalen))
    {
      if (!skipped[dnskey.algorithm]) {
        dns_zone_log(zone, ISC_LOG_INFO,
               "Managed keys for '%s' skipping "
               "unsupported algorithm %u",
               namebuf, dnskey.algorithm);
      }
      skipped[dnskey.algorithm] = true;
      continue;
    }

    revoked = ((dnskey.flags & DNS_KEYFLAG_REVOKE) != 0);

    if (matchkey(keydataset, &dnskeyrr)) {
      dns_rdata_reset(&keydatarr);
      dns_rdataset_current(keydataset, &keydatarr);
      result = dns_rdata_tostruct(&keydatarr, &keydata);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);

      if (revoked && revocable(fetch, &keydata)) {
        if (keydata.addhd > now) {
          /*
           * Key wasn't trusted yet, and now
           * it's been revoked?  Just remove it
           */
          deletekey = true;
          dnssec_log(zone, ISC_LOG_INFO,
               "Pending key %hu for "
               "zone %s is now revoked: "
               "deleting from the "
               "managed keys database",
               keytag, namebuf);
        } else if (keydata.removehd == 0) {
          /*
           * Remove key from secroots.
           */
          dns_view_untrust(zone->view, keyname,
               &dnskey);

          /* If initializing, delete now */
          if (keydata.addhd == 0) {
            deletekey = true;
          } else {
            keydata.removehd =
              now +
              dns_zone_mkey_month;
            keydata.flags |=
              DNS_KEYFLAG_REVOKE;
          }

          dnssec_log(zone, ISC_LOG_INFO,
               "Trusted key %hu for "
               "zone %s is now revoked",
               keytag, namebuf);
        } else if (keydata.removehd < now) {
          /* Scheduled for removal */
          deletekey = true;

          dnssec_log(zone, ISC_LOG_INFO,
               "Revoked key %hu for "
               "zone %s removal timer "
               "complete: deleting from "
               "the managed keys database",
               keytag, namebuf);
        }
      } else if (revoked && keydata.removehd == 0) {
        dnssec_log(zone, ISC_LOG_WARNING,
             "Active key %hu for zone "
             "%s is revoked but "
             "did not self-sign; "
             "ignoring",
             keytag, namebuf);
        continue;
      } else if (secure) {
        if (keydata.removehd != 0) {
          /*
           * Key isn't revoked--but it
           * seems it used to be.
           * Remove it now and add it
           * back as if it were a fresh key,
           * with a 30-day acceptance timer.
           */
          deletekey = true;
          newkey = true;
          keydata.removehd = 0;
          keydata.addhd = now +
              dns_zone_mkey_month;

          dnssec_log(zone, ISC_LOG_INFO,
               "Revoked key %hu for "
               "zone %s has returned: "
               "starting 30-day "
               "acceptance timer",
               keytag, namebuf);
        } else if (keydata.addhd > now) {
          pending++;
        } else if (keydata.addhd == 0) {
          keydata.addhd = now;
        }

        if (keydata.addhd <= now) {
          trustkey = true;
          dnssec_log(zone, ISC_LOG_INFO,
               "Key %hu for zone %s "
               "is now trusted (%s)",
               keytag, namebuf,
               initial ? "initializing key "
                   "verified"
                 : "acceptance timer "
                   "complete");
        }
      } else if (keydata.addhd > now) {
        /*
         * Not secure, and key is pending:
         * reset the acceptance timer
         */
        pending++;
        keydata.addhd = now + dns_zone_mkey_month;
        dnssec_log(zone, ISC_LOG_INFO,
             "Pending key %hu "
             "for zone %s was "
             "not validated: restarting "
             "30-day acceptance timer",
             keytag, namebuf);
      }

      if (!deletekey && !newkey) {
        updatekey = true;
      }
    } else if (secure) {
      /*
       * Key wasn't in the key zone but it's
       * revoked now anyway, so just skip it
       */
      if (revoked) {
        continue;
      }

      /* Key wasn't in the key zone: add it */
      newkey = true;

      if (initializing) {
        dnssec_log(zone, ISC_LOG_WARNING,
             "Initializing automatic trust "
             "anchor management for zone '%s'; "
             "DNSKEY ID %hu is now trusted, "
             "waiving the normal 30-day "
             "waiting period.",
             namebuf, keytag);
        trustkey = true;
      } else {
        dnssec_log(zone, ISC_LOG_INFO,
             "New key %hu observed "
             "for zone '%s': "
             "starting 30-day "
             "acceptance timer",
             keytag, namebuf);
      }
    } else {
      /*
       * No previously known key, and the key is not
       * secure, so skip it.
       */
      continue;
    }

    /* Delete old version */
    if (deletekey || !newkey) {
      CHECK(update_one_rr(kfetch->db, ver, &diff,
              DNS_DIFFOP_DEL, keyname, 0,
              &keydatarr));
    }

    if (updatekey) {
      /* Set refresh timer */
      keydata.refresh = refresh_time(fetch, false);
      dns_rdata_reset(&keydatarr);
      isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
      result = dns_rdata_fromstruct(&keydatarr, zone->rdclass,
                  dns_rdatatype_keydata,
                  &keydata, &keyb);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_WARNING,
             "dns_rdata_fromstruct failed: "
             "KEYDATA %hu: %s",
             keytag, isc_result_totext(result));
        continue;
      }

      /* Insert updated version */
      CHECK(update_one_rr(kfetch->db, ver, &diff,
              DNS_DIFFOP_ADD, keyname, 0,
              &keydatarr));
    } else if (newkey) {
      /* Convert DNSKEY to KEYDATA */
      result = dns_rdata_tostruct(&dnskeyrr, &dnskey);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      dns_keydata_fromdnskey(&keydata, &dnskey, 0, 0, 0);
      keydata.addhd = initializing
            ? now
            : now + dns_zone_mkey_month;
      keydata.refresh = refresh_time(fetch, false);
      dns_rdata_reset(&keydatarr);
      isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
      CHECK(dns_rdata_fromstruct(&keydatarr, zone->rdclass,
               dns_rdatatype_keydata,
               &keydata, &keyb));

      /* Insert into key zone */
      CHECK(update_one_rr(kfetch->db, ver, &diff,
              DNS_DIFFOP_ADD, keyname, 0,
              &keydatarr));
    }

    if (trustkey) {
      /* Trust this key. */
      result = dns_rdata_tostruct(&dnskeyrr, &dnskey);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      trust_key(zone, keyname, &dnskey, false);
    }

    if (secure && !deletekey) {
      INSIST(newkey || updatekey);
      set_refreshkeytimer(zone, &keydata, now, false);
    }
  }

  /*
   * RFC5011 says, "A trust point that has all of its trust anchors
   * revoked is considered deleted and is treated as if the trust
   * point was never configured."  But if someone revoked their
   * active key before the standby was trusted, that would mean the
   * zone would suddenly be nonsecured.  We avoid this by checking to
   * see if there's pending keydata.  If so, we put a null key in
   * the security roots; then all queries to the zone will fail.
   */
  if (pending != 0) {
    fail_secure(zone, keyname);
  }

done:
  if (!ISC_LIST_EMPTY(diff.tuples)) {
    /* Write changes to journal file. */
    CHECK(update_soa_serial(zone, kfetch->db, ver, &diff, mctx,
          zone->updatemethod));
    CHECK(zone_journal(zone, &diff, NULL, "keyfetch_done"));
    commit = true;

    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
    zone_needdump(zone, 30);
  } else if (result == ISC_R_NOMORE) {
    /*
     * If "updatekey" was true for all keys found in the DNSKEY
     * response and the previous update of those keys happened
     * during the same second (only possible if a key refresh was
     * externally triggered), it may happen that all relevant
     * update_one_rr() calls will return ISC_R_SUCCESS, but
     * diff.tuples will remain empty.  Reset result to
     * ISC_R_SUCCESS to prevent a bogus warning from being logged.
     */
    result = ISC_R_SUCCESS;
  }

cleanup:
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "error during trust anchor processing (%s): "
         "DNSSEC validation may be at risk",
         isc_result_totext(result));
  }

  dns_diff_clear(&diff);

  if (ver != NULL) {
    dns_db_closeversion(kfetch->db, &ver, commit);
  }

  if (secroots != NULL) {
    dns_keytable_detach(&secroots);
  }

  INSIST(ver == NULL);

  return result;
}

/*
 * Refresh the data in the key zone.  Initiate a fetch to look up
 * DNSKEY records at the trust anchor name.
 */
static void
zone_refreshkeys(dns_zone_t *zone) {
  isc_result_t result;
  dns_rriterator_t rrit;
  dns_db_t *db = NULL;
  dns_dbversion_t *ver = NULL;
  dns_diff_t diff;
  dns_rdata_keydata_t kd;
  isc_stdtime_t now = isc_stdtime_now();
  bool commit = false;
  bool fetching = false;
  bool timerset = false;

  ENTER;
  REQUIRE(zone->db != NULL);

  LOCK_ZONE(zone);
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    isc_time_settoepoch(&zone->refreshkeytime);
    UNLOCK_ZONE(zone);
    return;
  }

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  dns_db_attach(zone->db, &db);
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

  dns_diff_init(zone->mctx, &diff);

  CHECK(dns_db_newversion(db, &ver));

  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESHING);

  dns_rriterator_init(&rrit, db, ver, 0);
  for (result = dns_rriterator_first(&rrit); result == ISC_R_SUCCESS;
       result = dns_rriterator_nextrrset(&rrit))
  {
    isc_stdtime_t timer = 0xffffffff;
    dns_name_t *name = NULL;
    dns_rdataset_t *kdset = NULL;
    uint32_t ttl;

    dns_rriterator_current(&rrit, &name, &ttl, &kdset, NULL);
    if (kdset == NULL || kdset->type != dns_rdatatype_keydata ||
        !dns_rdataset_isassociated(kdset))
    {
      continue;
    }

    /*
     * Scan the stored keys looking for ones that need
     * removal or refreshing
     */
    DNS_RDATASET_FOREACH(kdset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(kdset, &rdata);
      result = dns_rdata_tostruct(&rdata, &kd);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);

      /* Removal timer expired? */
      if (kd.removehd != 0 && kd.removehd < now) {
        dns_rriterator_pause(&rrit);
        CHECK(update_one_rr(db, ver, &diff,
                DNS_DIFFOP_DEL, name, ttl,
                &rdata));
        continue;
      }

      /* Acceptance timer expired? */
      if (kd.addhd <= now) {
        timer = kd.addhd;
      }

      /* Or do we just need to refresh the keyset? */
      if (timer > kd.refresh) {
        timer = kd.refresh;
      }

      dns_rriterator_pause(&rrit);
      set_refreshkeytimer(zone, &kd, now, false);
      timerset = true;
    }

    if (timer > now) {
      continue;
    }

    dns_rriterator_pause(&rrit);

#ifdef ENABLE_AFL
    if (!dns_fuzzing_resolver) {
#endif /* ifdef ENABLE_AFL */
      dns_zonefetch_t *fetch = NULL;
      dns_keyfetch_t *kfetch = NULL;

      /*
       * This is a special query for RFC5011 maintenance
       * of a trust anchor. We will be validating it
       * in keyfetch_done() against a previously-known
       * trust anchor; we do not want the normal
       * validation process to occur.  We set
       * DNS_FETCHOPT_NOVALIDATE to suppress validation
       * in the resolver, and DNS_FETCHOPT_UNSHARED so
       * this fetch isn't combined with another one that
       * might be validating.
       *
       * We must also use DNS_FETCHOPT_NOCACHED, because
       * if it was not set and the cache still held a
       * non-expired, validated version of the DNSKEY,
       * then we'd receive the old, cached version
       * instead of the new response - the old version
       * would have a higher trust level.
       */
      fetch = isc_mem_get(zone->mctx,
              sizeof(dns_zonefetch_t));
      *fetch = (dns_zonefetch_t){
        .zone = zone,
        .options = DNS_FETCHOPT_NOVALIDATE |
             DNS_FETCHOPT_UNSHARED |
             DNS_FETCHOPT_NOCACHED,
        .fetchtype = ZONEFETCHTYPE_KEY,
        .fetchmethods =
          (dns_zonefetch_methods_t){
            .start_fetch = keyfetch_start,
            .continue_fetch =
              keyfetch_continue,
            .cancel_fetch = keyfetch_cancel,
            .cleanup_fetch =
              keyfetch_cleanup,
            .done_fetch = keyfetch_done,
          },
      };
      isc_mem_attach(zone->mctx, &fetch->mctx);

      zone->fetchcount[ZONEFETCHTYPE_KEY]++;

      kfetch = &fetch->fetchdata.keyfetch;
      dns_rdataset_init(&kfetch->keydataset);
      dns_rdataset_clone(kdset, &kfetch->keydataset);
      dns_db_attach(db, &kfetch->db);

      dns_zonefetch_schedule(fetch, name);

      if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
        char namebuf[DNS_NAME_FORMATSIZE];
        dns_name_format(name, namebuf, sizeof(namebuf));
        dnssec_log(zone, ISC_LOG_DEBUG(3),
             "Creating key fetch in "
             "zone_refreshkeys() for '%s'",
             namebuf);
      }
      fetching = true;
#ifdef ENABLE_AFL
    }
#endif /* ifdef ENABLE_AFL */
  }
  if (!ISC_LIST_EMPTY(diff.tuples)) {
    CHECK(update_soa_serial(zone, db, ver, &diff, zone->mctx,
          zone->updatemethod));
    CHECK(zone_journal(zone, &diff, NULL, "zone_refreshkeys"));
    commit = true;
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
    zone_needdump(zone, 30);
  }

cleanup:
  if (!timerset) {
    isc_time_settoepoch(&zone->refreshkeytime);
  }

  if (!fetching) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESHING);
  }

  dns_diff_clear(&diff);
  if (ver != NULL) {
    dns_rriterator_destroy(&rrit);
    dns_db_closeversion(db, &ver, commit);
  }
  dns_db_detach(&db);

  UNLOCK_ZONE(zone);

  INSIST(ver == NULL);
}

typedef enum inline_sync_action {
  inline_sync_none = 0,
  inline_sync_bootstrap,
  inline_sync_incremental_start,
  inline_sync_incremental_continue,
} inline_sync_action_t;

/*
 * Inline-signing secure zones pull raw-zone changes during maintenance.
 * Raw-zone updates queue immediate secure maintenance.
 */
static inline_sync_action_t
zone_inline_sync_action(dns_zone_t *zone) {
  REQUIRE(LOCKED_ZONE(zone));

  if (!dns__zone_inline_secure(zone)) {
    return inline_sync_none;
  }

  if (zone->inline_sync_phase == inline_sync_full) {
    zone->inline_sync_phase = inline_sync_idle;
    /*
     * A full rebuild replaces any parked incremental sync state;
     * zone_maintenance() cancels zone->iss before bootstrapping.
     */
    return inline_sync_bootstrap;
  }

  if (zone->iss != NULL) {
    return inline_sync_incremental_continue;
  }

  if (zone->inline_sync_phase == inline_sync_incremental) {
    /*
     * An incremental sync is a one-shot raw-to-secure request.
     * Parked incremental syncs are continued before this request is
     * consumed, so raw updates that arrive during signing are not
     * collapsed into continuation wakes.
     */
    zone->inline_sync_phase = inline_sync_idle;
    if (zone->db == NULL) {
      return inline_sync_bootstrap;
    }
    return inline_sync_incremental_start;
  }

  INSIST(zone->inline_sync_phase == inline_sync_idle);
  return inline_sync_none;
}

static bool
zone_inline_sync_pending(dns_zone_t *zone) {
  REQUIRE(LOCKED_ZONE(zone));

  return dns__zone_inline_secure(zone) &&
         (zone->iss != NULL ||
    zone->inline_sync_phase == inline_sync_incremental ||
    zone->inline_sync_phase == inline_sync_full);
}

static void
zone_maintenance(dns_zone_t *zone) {
  isc_time_t now;
  isc_result_t result;
  bool load_pending, exiting, dumping, viewok = false, notify;
  bool refreshkeys, rekey;
  bool sign = false, resign = false, chain = false, warn_expire = false;
  inline_sync_action_t inline_sync = inline_sync_none;

  REQUIRE(DNS_ZONE_VALID(zone));
  ENTER;

  /*
   * Are we pending load/reload, exiting, or unconfigured
   * (e.g. because of a syntax failure in the config file)?
   * If so, don't attempt maintenance.
   */
  LOCK_ZONE(zone);
  load_pending = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADPENDING);
  exiting = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING);
  if (!load_pending && !exiting && zone->view != NULL) {
    dns_adb_t *adb = NULL;
    dns_view_getadb(zone->view, &adb);
    if (adb != NULL) {
      dns_adb_detach(&adb);
      viewok = true;
    }
  }
  UNLOCK_ZONE(zone);

  if (load_pending || exiting || !viewok) {
    return;
  }

  now = isc_time_now();

  /*
   * Expire check.
   */
  switch (zone->type) {
  case dns_zone_redirect:
    if (dns_remote_addresses(&zone->primaries) == NULL) {
      break;
    }
    FALLTHROUGH;
  case dns_zone_secondary:
  case dns_zone_mirror:
  case dns_zone_stub:
    LOCK_ZONE(zone);
    if (isc_time_compare(&now, &zone->expiretime) >= 0 &&
        DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
    {
      zone_expire(zone);
      zone->refreshtime = now;
    }
    UNLOCK_ZONE(zone);
    break;
  default:
    break;
  }

  /*
   * Up to date check.
   */
  switch (zone->type) {
  case dns_zone_redirect:
    if (dns_remote_addresses(&zone->primaries) == NULL) {
      break;
    }
    FALLTHROUGH;
  case dns_zone_secondary:
  case dns_zone_mirror:
  case dns_zone_stub:
    LOCK_ZONE(zone);
    if (isc_time_compare(&now, &zone->refreshtime) >= 0) {
      zone_refresh(zone);
    }
    UNLOCK_ZONE(zone);
    break;
  default:
    break;
  }

  /*
   * Secondaries send notifies before backing up to disk,
   * primaries after.
   */
  LOCK_ZONE(zone);
  if (zone->notifysoa.notifydefer != 0 &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOTIFYNODEFER) &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOTIFYDEFERRED))
  {
    if (isc_time_compare(&now, &zone->notifytime) > 0) {
      zone->notifytime = now;
    }
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOTIFYDEFERRED);
    DNS_ZONE_TIME_ADD(&zone->notifytime,
          zone->notifysoa.notifydefer,
          &zone->notifytime);
  }
  notify = (zone->type == dns_zone_secondary ||
      zone->type == dns_zone_mirror) &&
     (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) ||
      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDSTARTUPNOTIFY)) &&
     isc_time_compare(&now, &zone->notifytime) >= 0;
  UNLOCK_ZONE(zone);

  if (notify) {
    zone_notify(zone, &now);
  }

  /*
   * Do we need to consolidate the backing store?
   */
  switch (zone->type) {
  case dns_zone_primary:
  case dns_zone_secondary:
  case dns_zone_mirror:
  case dns_zone_key:
  case dns_zone_redirect:
  case dns_zone_stub:
    LOCK_ZONE(zone);
    if (zone->masterfile != NULL &&
        isc_time_compare(&now, &zone->dumptime) >= 0 &&
        DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
        DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP))
    {
      dumping = was_dumping(zone);
    } else {
      dumping = true;
    }
    UNLOCK_ZONE(zone);
    if (!dumping) {
      result = zone_dump(zone, true); /* loop locked */
      if (result != ISC_R_SUCCESS) {
        dns_zone_log(zone, ISC_LOG_WARNING,
               "dump failed: %s",
               isc_result_totext(result));
      }
    }
    break;
  default:
    break;
  }

  /*
   * Primary/redirect zones send notifies now, if needed
   */
  switch (zone->type) {
  case dns_zone_primary:
  case dns_zone_redirect:
    LOCK_ZONE(zone);
    notify = (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) ||
        DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDSTARTUPNOTIFY)) &&
       isc_time_compare(&now, &zone->notifytime) >= 0;
    UNLOCK_ZONE(zone);
    if (notify) {
      zone_notify(zone, &now);
    }
  default:
    break;
  }

  LOCK_ZONE(zone);
  inline_sync = zone_inline_sync_action(zone);
  UNLOCK_ZONE(zone);

  switch (inline_sync) {
  case inline_sync_bootstrap:
    zone_clear_inline_sync(zone);
    inline_secure_bootstrap(zone);
    break;
  case inline_sync_incremental_start:
    inline_sync_run(zone);
    break;
  case inline_sync_incremental_continue:
    inline_sync_resume(zone);
    break;
  case inline_sync_none:
    break;
  }

  /*
   * Apply one queued DB mutation before snapshotting DNSSEC maintenance
   * timers, so chain/sign work observes the resulting zone state.
   */
  zone_process_maintenance_request(zone);

  LOCK_ZONE(zone);
  if (zone_inline_sync_pending(zone)) {
    dns__zone_settimer(zone, now);
    UNLOCK_ZONE(zone);
    return;
  }
  UNLOCK_ZONE(zone);

  switch (zone->type) {
  case dns_zone_primary:
  case dns_zone_redirect:
  case dns_zone_secondary:
    LOCK_ZONE(zone);
    sign = time_greater_equal(now, zone->signingtime);
    resign = time_greater_equal(now, zone->resigntime);
    chain = time_greater_equal(now, zone->nsec3chaintime);
    warn_expire = time_greater_equal(now, zone->keywarntime);
    UNLOCK_ZONE(zone);
    break;

  default:
    break;
  }

  /*
   * Do we need to refresh keys?
   */
  switch (zone->type) {
  case dns_zone_key:
    LOCK_ZONE(zone);
    refreshkeys = isc_time_compare(&now, &zone->refreshkeytime) >=
              0 &&
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESHING);
    UNLOCK_ZONE(zone);
    if (refreshkeys) {
      zone_refreshkeys(zone);
    }
    break;
  case dns_zone_primary:
    LOCK_ZONE(zone);
    rekey = time_greater_equal(now, zone->refreshkeytime);
    UNLOCK_ZONE(zone);
    if (rekey) {
      zone_rekey(zone);
    }
  default:
    break;
  }

  switch (zone->type) {
  case dns_zone_primary:
  case dns_zone_redirect:
  case dns_zone_secondary:
    /*
     * Do the DNSSEC work that was due before key maintenance.
     */
    if (chain) {
      zone_nsec3chain(zone);
    } else if (sign) {
      zone_sign(zone);
    } else if (resign) {
      zone_resigninc(zone);
    }

    /*
     * Do we need to issue a key expiry warning?
     */
    if (warn_expire) {
      set_key_expiry_warning(zone, zone->key_expiry,
                 isc_time_seconds(&now));
    }
    break;

  default:
    break;
  }
  LOCK_ZONE(zone);
  dns__zone_settimer(zone, now);
  UNLOCK_ZONE(zone);
}

void
dns_zone_markdirty(dns_zone_t *zone) {
  dns_zone_t *secure = NULL;

  /*
   * Obtaining a lock on zone->secure could result in a deadlock due to
   * a LOR, so spin if both locks cannot be obtained.
   */
again:
  LOCK_ZONE(zone);
  if (zone->type == dns_zone_primary) {
    if (dns__zone_inline_raw(zone)) {
      isc_result_t result;

      secure = zone->secure;
      INSIST(secure != zone);
      TRYLOCK_ZONE(result, secure);
      if (result != ISC_R_SUCCESS) {
        UNLOCK_ZONE(zone);
        secure = NULL;
        isc_thread_yield();
        goto again;
      }

      zone_schedule_inline_sync(secure,
              inline_sync_incremental);
    }

    /* XXXMPA make separate call back */
    dns__zone_set_resigntime(zone);
    if (zone->loop != NULL) {
      dns__zone_settimer(zone, isc_time_now());
    }
  }
  if (secure != NULL) {
    UNLOCK_ZONE(secure);
  }
  zone_needdump(zone, DNS_DUMP_DELAY);
  UNLOCK_ZONE(zone);
}

static void
zone_expire(dns_zone_t *zone) {
  dns_db_t *db = NULL;

  /*
   * 'zone' locked by caller.
   */

  REQUIRE(LOCKED_ZONE(zone));

  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXPIRED);
  zone->refresh = DNS_ZONE_DEFAULTREFRESH;
  zone->retry = DNS_ZONE_DEFAULTRETRY;
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_HAVETIMERS);

  dns_zone_log(zone, ISC_LOG_WARNING, "expired");

  /*
   * An RPZ zone has expired; before unloading it, we must
   * first remove it from the RPZ summary database. The
   * easiest way to do this is "update" it with an empty
   * database so that the update callback synchronizes
   * the diff automatically.
   */
  if (zone->rpzs != NULL && zone->rpz_num != DNS_RPZ_INVALID_NUM) {
    isc_result_t result;
    dns_rpz_zone_t *rpz = zone->rpzs->zones[zone->rpz_num];

    CHECK(dns_db_create(zone->mctx, ZONEDB_DEFAULT, &zone->origin,
            dns_dbtype_zone, zone->rdclass, 0, NULL,
            &db));
    CHECK(dns_rpz_dbupdate_callback(db, rpz));
    dns_zone_log(zone, ISC_LOG_WARNING,
           "response-policy zone expired; "
           "policies unloaded");
  }

cleanup:
  if (db != NULL) {
    dns_db_detach(&db);
  }

  zone_unload(zone);
}

static void
zone_refresh(dns_zone_t *zone) {
  isc_interval_t i;
  uint32_t oldflags;
  isc_result_t result;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    return;
  }

  /*
   * Set DNS_ZONEFLG_REFRESH so that there is only one refresh operation
   * in progress at a time.
   */

  oldflags = atomic_load(&zone->flags);
  if (dns_remote_addresses(&zone->primaries) == NULL) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOPRIMARIES);
    if ((oldflags & DNS_ZONEFLG_NOPRIMARIES) == 0) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_ERROR,
              "cannot refresh: no primaries");
    }
    return;
  }
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESH);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOEDNS);
  if ((oldflags & (DNS_ZONEFLG_REFRESH | DNS_ZONEFLG_LOADING)) != 0) {
    return;
  }

  /*
   * Set the next refresh time as if refresh check has failed.
   * Setting this to the retry time will do that.  XXXMLG
   * If we are successful it will be reset using zone->refresh.
   */
  isc_interval_set(&i, zone->retry - isc_random_uniform(zone->retry / 4),
       0);
  result = isc_time_nowplusinterval(&zone->refreshtime, &i);
  if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_WARNING,
            "isc_time_nowplusinterval() failed: %s",
            isc_result_totext(result));
  }

  /*
   * When lacking user-specified timer values from the SOA,
   * do exponential backoff of the retry time up to a
   * maximum of six hours.
   */
  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_HAVETIMERS)) {
    zone->retry = ISC_MIN(zone->retry * 2, 6 * 3600);
  }

  dns_remote_reset(&zone->primaries, true);

  /* initiate soa query */
  queue_soa_query(zone);
}

static void
zone_refresh_async(void *arg) {
  dns_zone_t *zone = arg;

  LOCK_ZONE(zone);
  zone_refresh(zone);
  UNLOCK_ZONE(zone);

  dns_zone_detach(&zone);
}

void
dns_zone_refresh(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  dns_zone_ref(zone);
  isc_async_run(zone->loop, zone_refresh_async, zone);
}

static isc_result_t
zone_journal_rollforward(dns_zone_t *zone, dns_db_t *db, bool *needdump,
       bool *fixjournal) {
  dns_journal_t *journal = NULL;
  unsigned int options;
  isc_result_t result;

  if (zone->type == dns_zone_primary &&
      (dns__zone_inline_secure(zone) ||
       (zone->update_acl != NULL || zone->ssutable != NULL)))
  {
    options = DNS_JOURNALOPT_RESIGN;
  } else {
    options = 0;
  }

  result = dns_journal_open(zone->mctx, zone->journal, DNS_JOURNAL_READ,
          &journal);
  if (result == ISC_R_NOTFOUND) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_DEBUG(3),
            "no journal file, but that's OK ");
    return ISC_R_SUCCESS;
  } else if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_ERROR,
            "journal open failed: %s",
            isc_result_totext(result));
    return result;
  }

  if (dns_journal_empty(journal)) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_DEBUG(1),
            "journal empty");
    dns_journal_destroy(&journal);
    return ISC_R_SUCCESS;
  }

  result = dns_journal_rollforward(journal, db, options);
  switch (result) {
  case ISC_R_SUCCESS:
    *needdump = true;
    FALLTHROUGH;
  case DNS_R_UPTODATE:
    if (dns_journal_recovered(journal)) {
      *fixjournal = true;
      dns_zone_logc(
        zone, DNS_LOGCATEGORY_ZONELOAD,
        ISC_LOG_DEBUG(1),
        "journal rollforward completed successfully "
        "using old journal format: %s",
        isc_result_totext(result));
    } else {
      dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD,
              ISC_LOG_DEBUG(1),
              "journal rollforward completed "
              "successfully: %s",
              isc_result_totext(result));
    }

    dns_journal_destroy(&journal);
    return ISC_R_SUCCESS;
  case ISC_R_NOTFOUND:
  case ISC_R_RANGE:
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_ERROR,
            "journal rollforward failed: journal out of sync "
            "with zone");
    dns_journal_destroy(&journal);
    return result;
  default:
    dns_zone_logc(zone, DNS_LOGCATEGORY_ZONELOAD, ISC_LOG_ERROR,
            "journal rollforward failed: %s",
            isc_result_totext(result));
    dns_journal_destroy(&journal);
    return result;
  }
}

static void
zone_journal_compact(dns_zone_t *zone, dns_db_t *db, uint32_t serial) {
  isc_result_t result;
  int32_t journalsize;
  dns_dbversion_t *ver = NULL;
  uint64_t dbsize;
  uint32_t options = 0;

  INSIST(LOCKED_ZONE(zone));
  if (dns__zone_inline_raw(zone)) {
    INSIST(LOCKED_ZONE(zone->secure));
  }

  journalsize = zone->journalsize;
  if (journalsize == -1) {
    journalsize = DNS_JOURNAL_SIZE_MAX;
    dns_db_currentversion(db, &ver);
    result = dns_db_getsize(db, ver, NULL, &dbsize);
    dns_db_closeversion(db, &ver, false);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "zone_journal_compact: "
             "could not get zone size: %s",
             isc_result_totext(result));
    } else if (dbsize < DNS_JOURNAL_SIZE_MAX / 2) {
      journalsize = (int32_t)dbsize * 2;
    }
  }
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FIXJOURNAL)) {
    options |= DNS_JOURNAL_COMPACTALL;
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FIXJOURNAL);
    zone_debuglog(zone, __func__, 1, "repair full journal");
  } else {
    zone_debuglog(zone, __func__, 1, "target journal size %d",
            journalsize);
  }
  result = dns_journal_compact(zone->mctx, zone->journal, serial, options,
             journalsize);
  switch (result) {
  case ISC_R_SUCCESS:
  case ISC_R_NOSPACE:
  case ISC_R_NOTFOUND:
    dns_zone_log(zone, ISC_LOG_DEBUG(3), "dns_journal_compact: %s",
           isc_result_totext(result));
    break;
  default:
    dns_zone_log(zone, ISC_LOG_ERROR,
           "dns_journal_compact failed: %s",
           isc_result_totext(result));
    break;
  }
}

isc_result_t
dns_zone_flush(dns_zone_t *zone) {
  isc_result_t result = ISC_R_SUCCESS;
  bool dumping;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FLUSH);
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
      zone->masterfile != NULL)
  {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDCOMPACT);
    result = ISC_R_ALREADYRUNNING;
    dumping = was_dumping(zone);
  } else {
    dumping = true;
  }
  UNLOCK_ZONE(zone);
  if (!dumping) {
    result = zone_dump(zone, true);
  }
  return result;
}

static void
zone_needdump(dns_zone_t *zone, unsigned int delay) {
  isc_time_t dumptime;
  isc_time_t now;

  /*
   * 'zone' locked by caller
   */

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  ENTER;

  /*
   * Do we have a place to dump to and are we loaded?
   */
  if (zone->masterfile == NULL ||
      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) == 0)
  {
    return;
  }

  now = isc_time_now();
  /* add some noise */
  DNS_ZONE_JITTER_ADD(&now, delay, &dumptime);

  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
  if (isc_time_isepoch(&zone->dumptime) ||
      isc_time_compare(&zone->dumptime, &dumptime) > 0)
  {
    zone->dumptime = dumptime;
  }
  if (zone->loop != NULL) {
    dns__zone_settimer(zone, now);
  }
}

static void
dump_done(void *arg, isc_result_t result) {
  dns_zone_t *zone = arg;
  dns_zone_t *secure = NULL;
  bool again = false;
  bool compact = false;
  uint32_t serial;
  isc_result_t tresult = ISC_R_UNSET;

  REQUIRE(DNS_ZONE_VALID(zone));

  ENTER;

  /*
   * Adjust modification time of zone file to preserve expire timing.
   */
  if ((zone->type == dns_zone_secondary ||
       zone->type == dns_zone_mirror ||
       zone->type == dns_zone_redirect) &&
      result == ISC_R_SUCCESS)
  {
    LOCK_ZONE(zone);
    isc_time_t when;
    isc_interval_t i;
    isc_interval_set(&i, zone->expire, 0);
    result = isc_time_subtract(&zone->expiretime, &i, &when);
    if (result == ISC_R_SUCCESS) {
      (void)isc_file_settime(zone->masterfile, &when);
    } else {
      result = ISC_R_SUCCESS;
    }
    UNLOCK_ZONE(zone);
  }

  if (result == ISC_R_SUCCESS && zone->journal != NULL) {
    tresult = dns_dumpctx_serial(zone->dumpctx, &serial);
  }

  if (tresult == ISC_R_SUCCESS) {
    /*
     * Handle lock order inversion.
     */
  again:
    LOCK_ZONE(zone);
    if (dns__zone_inline_raw(zone)) {
      secure = zone->secure;
      INSIST(secure != zone);
      TRYLOCK_ZONE(result, secure);
      if (result != ISC_R_SUCCESS) {
        UNLOCK_ZONE(zone);
        secure = NULL;
        isc_thread_yield();
        goto again;
      }
    }

    /*
     * If there is a secure version of this zone
     * use its serial if it is less than ours.
     */
    if (secure != NULL) {
      uint32_t sserial;
      isc_result_t mresult;

      ZONEDB_LOCK(&secure->dblock, isc_rwlocktype_read);
      if (secure->db != NULL) {
        mresult = dns_db_getsoaserial(zone->secure->db,
                    NULL, &sserial);
        if (mresult == ISC_R_SUCCESS &&
            isc_serial_lt(sserial, serial))
        {
          serial = sserial;
        }
      }
      ZONEDB_UNLOCK(&secure->dblock, isc_rwlocktype_read);
    }
    if (zone->xfr == NULL) {
      dns_db_t *zdb = NULL;
      if (dns_zone_getdb(zone, &zdb) == ISC_R_SUCCESS) {
        zone_journal_compact(zone, zdb, serial);
        dns_db_detach(&zdb);
      }
    } else {
      compact = true;
      zone->compact_serial = serial;
    }
    if (secure != NULL) {
      UNLOCK_ZONE(secure);
    }
    UNLOCK_ZONE(zone);
  }

  LOCK_ZONE(zone);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_DUMPING);
  if (compact) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDCOMPACT);
  }
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SHUTDOWN)) {
    /*
     * If DNS_ZONEFLG_SHUTDOWN is set, all external references to
     * the zone are gone, which means it is in the process of being
     * cleaned up, so do not reschedule dumping.
     *
     * Detach from the raw version of the zone in case this
     * operation has been deferred in zone_shutdown().
     */
    if (zone->raw != NULL) {
      dns_zone_detach(&zone->raw);
    }
    if (result == ISC_R_SUCCESS) {
      DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FLUSH);
    }
  } else if (result != ISC_R_SUCCESS && result != ISC_R_CANCELED) {
    /*
     * Try again in a short while.
     */
    zone_needdump(zone, DNS_DUMP_DELAY);
  } else if (result == ISC_R_SUCCESS &&
       DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) &&
       DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
       DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
  {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DUMPING);
    isc_time_settoepoch(&zone->dumptime);
    again = true;
  } else if (result == ISC_R_SUCCESS) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FLUSH);
  }

  if (zone->dumpctx != NULL) {
    dns_dumpctx_detach(&zone->dumpctx);
  }
  UNLOCK_ZONE(zone);
  if (again) {
    (void)zone_dump(zone, false);
  }
  dns_zone_idetach(&zone);
}

static isc_result_t
zone_dump(dns_zone_t *zone, bool compact) {
  isc_result_t result;
  dns_dbversion_t *version = NULL;
  bool again = false;
  dns_db_t *db = NULL;
  char *masterfile = NULL;
  dns_masterformat_t masterformat = dns_masterformat_none;
  const dns_master_style_t *masterstyle = NULL;
  dns_masterrawheader_t rawdata;
  bool inline_secure;

  /*
   * 'compact' MUST only be set if we are loop locked.
   */

  REQUIRE(DNS_ZONE_VALID(zone));
  ENTER;

redo:
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  LOCK_ZONE(zone);
  if (zone->masterfile != NULL) {
    masterfile = isc_mem_strdup(zone->mctx, zone->masterfile);
    masterformat = zone->masterformat;
  }
  if (zone->type == dns_zone_key) {
    masterstyle = &dns_master_style_keyzone;
  } else if (zone->masterstyle != NULL) {
    masterstyle = zone->masterstyle;
  } else {
    masterstyle = &dns_master_style_default;
  }
  UNLOCK_ZONE(zone);
  if (db == NULL) {
    result = DNS_R_NOTLOADED;
    goto fail;
  }
  if (masterfile == NULL) {
    result = DNS_R_NOMASTERFILE;
    goto fail;
  }

  dns_db_currentversion(db, &version);

  dns_master_initrawheader(&rawdata);

  LOCK_ZONE(zone);
  inline_secure = dns__zone_inline_secure(zone);
  UNLOCK_ZONE(zone);

  if (inline_secure) {
    get_raw_serial(zone->raw, &rawdata);
  }

  if (compact && zone->type != dns_zone_stub) {
    LOCK_ZONE(zone);
    zone_iattach(zone, &(dns_zone_t *){ NULL });

    INSIST(zone != zone->raw);

    result = dns_master_dumpasync(
      zone->mctx, db, version, masterstyle, masterfile,
      zone->loop, dump_done, zone, &zone->dumpctx,
      masterformat, &rawdata);

    UNLOCK_ZONE(zone);
    if (result != ISC_R_SUCCESS) {
      dns_zone_idetach(&(dns_zone_t *){ zone });
      goto fail;
    }
    result = DNS_R_CONTINUE;
  } else {
    result = dns_master_dump(zone->mctx, db, version, masterstyle,
           masterfile, masterformat, &rawdata);
    if ((zone->type == dns_zone_secondary ||
         zone->type == dns_zone_mirror ||
         zone->type == dns_zone_redirect) &&
        result == ISC_R_SUCCESS)
    {
      isc_time_t when;
      isc_interval_t i;
      isc_interval_set(&i, zone->expire, 0);
      result = isc_time_subtract(&zone->expiretime, &i,
               &when);
      if (result == ISC_R_SUCCESS) {
        (void)isc_file_settime(zone->masterfile, &when);
      } else {
        result = ISC_R_SUCCESS;
      }
    }
  }
fail:
  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }
  if (masterfile != NULL) {
    isc_mem_free(zone->mctx, masterfile);
  }

  if (result == DNS_R_CONTINUE) {
    /*
     * Asyncronous write is in progress.  Zone flags will get
     * updated on completion.  Cleanup is complete.  We are done.
     */
    return ISC_R_SUCCESS;
  }

  again = false;
  LOCK_ZONE(zone);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_DUMPING);
  if (result != ISC_R_SUCCESS) {
    /*
     * Try again in a short while.
     */
    zone_needdump(zone, DNS_DUMP_DELAY);
  } else if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) &&
       DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
       DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
  {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DUMPING);
    isc_time_settoepoch(&zone->dumptime);
    again = true;
  } else {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FLUSH);
  }
  UNLOCK_ZONE(zone);
  if (again) {
    goto redo;
  }

  return result;
}

static isc_result_t
dumptostream(dns_zone_t *zone, FILE *fd, const dns_master_style_t *style,
       dns_masterformat_t format, const uint32_t rawversion) {
  isc_result_t result;
  dns_dbversion_t *version = NULL;
  dns_db_t *db = NULL;
  dns_masterrawheader_t rawdata;
  bool inline_secure;

  REQUIRE(DNS_ZONE_VALID(zone));

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    return DNS_R_NOTLOADED;
  }

  LOCK_ZONE(zone);
  inline_secure = dns__zone_inline_secure(zone);
  UNLOCK_ZONE(zone);

  dns_db_currentversion(db, &version);
  dns_master_initrawheader(&rawdata);
  if (rawversion == 0) {
    rawdata.flags |= DNS_MASTERRAW_COMPAT;
  } else if (inline_secure) {
    get_raw_serial(zone->raw, &rawdata);
  } else if (zone->sourceserialset) {
    rawdata.flags = DNS_MASTERRAW_SOURCESERIALSET;
    rawdata.sourceserial = zone->sourceserial;
  }
  result = dns_master_dumptostream(zone->mctx, db, version, style, format,
           &rawdata, fd);
  dns_db_closeversion(db, &version, false);
  dns_db_detach(&db);
  return result;
}

isc_result_t
dns_zone_dumptostream(dns_zone_t *zone, FILE *fd, dns_masterformat_t format,
          const dns_master_style_t *style,
          const uint32_t rawversion) {
  return dumptostream(zone, fd, style, format, rawversion);
}

void
dns_zone_unload(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  zone_unload(zone);
  UNLOCK_ZONE(zone);
}

static void
checkds_cancel(dns_zone_t *zone) {
  /*
   * 'zone' locked by caller.
   */

  REQUIRE(LOCKED_ZONE(zone));

  ISC_LIST_FOREACH(zone->checkds_requests, checkds, link) {
    if (checkds->find != NULL) {
      dns_adb_cancelfind(checkds->find);
    }
    if (checkds->request != NULL) {
      dns_request_cancel(checkds->request);
    }
  }
}

void
dns__zone_forward_cancel(dns_zone_t *zone) {
  /*
   * 'zone' locked by caller.
   */

  REQUIRE(LOCKED_ZONE(zone));

  ISC_LIST_FOREACH(zone->forwards, forward, link) {
    if (forward->request != NULL) {
      dns_request_cancel(forward->request);
    }
  }
}

static void
zone_unload(dns_zone_t *zone) {
  /*
   * 'zone' locked by caller.
   */

  REQUIRE(LOCKED_ZONE(zone));

  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) ||
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
  {
    if (zone->dumpctx != NULL) {
      dns_dumpctx_cancel(zone->dumpctx);
    }
  }
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
  zone_detachdb(zone);
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_LOADED);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);

  if (zone->type == dns_zone_mirror) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "mirror zone is no longer in use; "
           "reverting to normal recursion");
  }
}

void
dns_zone_notify(dns_zone_t *zone, bool nodefer) {
  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
  if (nodefer) {
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOTIFYDEFERRED)) {
      /*
       * We have previously deferred the notify, but we have a
       * new request not to defer it. Reverse the deferring
       * operation.
       */
      DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOTIFYDEFERRED);
      DNS_ZONE_TIME_SUBTRACT(&zone->notifytime,
                 zone->notifysoa.notifydefer,
                 &zone->notifytime);
    }
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOTIFYNODEFER);
  }
  dns__zone_settimer(zone, isc_time_now());
  UNLOCK_ZONE(zone);
}

static void
zone_notify(dns_zone_t *zone, isc_time_t *now) {
  dns_dbnode_t *node = NULL;
  dns_db_t *zonedb = NULL;
  dns_dbversion_t *version = NULL;
  dns_name_t *origin = NULL;
  dns_name_t primary;
  dns_rdata_ns_t ns;
  dns_rdata_soa_t soa;
  dns_rdata_t soardata = DNS_RDATA_INIT;
  uint32_t serial;
  dns_rdataset_t nsrdset;
  dns_rdataset_t soardset;
  isc_result_t result;
  isc_sockaddr_t src;
  isc_sockaddr_t dst;
  bool isqueued;
  dns_notifytype_t notifytype;
  unsigned int flags = 0;
  bool loggednotify = false;
  bool startup;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  startup = !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY |
               DNS_ZONEFLG_NEEDSTARTUPNOTIFY |
               DNS_ZONEFLG_NOTIFYNODEFER |
               DNS_ZONEFLG_NOTIFYDEFERRED);
  notifytype = zone->notifysoa.notifytype;
  DNS_ZONE_TIME_ADD(now, zone->notifysoa.notifydelay, &zone->notifytime);
  UNLOCK_ZONE(zone);

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) ||
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
  {
    return;
  }

  if (notifytype == dns_notifytype_no) {
    return;
  }

  if (notifytype == dns_notifytype_masteronly &&
      zone->type != dns_zone_primary)
  {
    return;
  }

  origin = &zone->origin;

  /*
   * Record that this was a notify due to starting up.
   */
  if (startup) {
    flags |= DNS_NOTIFY_STARTUP;
  }

  /*
   * Get SOA RRset.
   */
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &zonedb);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (zonedb == NULL) {
    return;
  }
  dns_db_currentversion(zonedb, &version);
  result = dns_db_findnode(zonedb, origin, false, &node);
  if (result != ISC_R_SUCCESS) {
    goto cleanup1;
  }

  dns_rdataset_init(&soardset);
  result = dns_db_findrdataset(zonedb, node, version, dns_rdatatype_soa,
             dns_rdatatype_none, 0, &soardset, NULL);
  if (result != ISC_R_SUCCESS) {
    goto cleanup2;
  }

  /*
   * Find serial and primary server's name.
   */
  dns_name_init(&primary);
  result = dns_rdataset_first(&soardset);
  if (result != ISC_R_SUCCESS) {
    goto cleanup3;
  }
  dns_rdataset_current(&soardset, &soardata);
  result = dns_rdata_tostruct(&soardata, &soa);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
  dns_name_dup(&soa.origin, zone->mctx, &primary);
  serial = soa.serial;
  dns_rdataset_disassociate(&soardset);

  /*
   * Enqueue notify requests for 'also-notify' servers.
   */
  LOCK_ZONE(zone);

  dns_remote_reset(&zone->alsonotify, false);
  while (!dns_remote_done(&zone->alsonotify)) {
    dns_tsigkey_t *key = NULL;
    dns_transport_t *transport = NULL;
    dns_notify_t *notify = NULL;
    dns_view_t *view = dns_zone_getview(zone);

    dst = dns_remote_curraddr(&zone->alsonotify);
    if (isc_sockaddr_disabled(&dst)) {
      goto next;
    }

    if (dns_remote_keyname(&zone->alsonotify) != NULL) {
      dns_name_t *keyname =
        dns_remote_keyname(&zone->alsonotify);
      (void)dns_view_gettsig(view, keyname, &key);
    }

    if (dns_remote_tlsname(&zone->alsonotify) != NULL) {
      dns_name_t *tlsname =
        dns_remote_tlsname(&zone->alsonotify);
      result = dns_view_gettransport(view, DNS_TRANSPORT_TLS,
                   tlsname, &transport);

      if (result == ISC_R_SUCCESS) {
        dns_zone_logc(
          zone, DNS_LOGCATEGORY_NOTIFY,
          ISC_LOG_INFO,
          "got TLS configuration for a notify");
      } else {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_ERROR,
                "could not get TLS configuration "
                "for zone transfer: %s",
                isc_result_totext(result));
        if (key != NULL) {
          dns_tsigkey_detach(&key);
        }
        goto next;
      }

      flags |= DNS_NOTIFY_TCP;
    }

    src = dns_remote_sourceaddr(&zone->alsonotify);
    INSIST(isc_sockaddr_pf(&src) == isc_sockaddr_pf(&dst));

    if (dns_notify_isqueued(&zone->notifysoa, dns_rdatatype_soa,
          zone->view->dstport, flags, NULL, &dst,
          key, transport))
    {
      if (key != NULL) {
        dns_tsigkey_detach(&key);
      }
      if (transport != NULL) {
        dns_transport_detach(&transport);
      }
      goto next;
    }

    dns_notify_create(zone->mctx, dns_rdatatype_soa,
          zone->view->dstport, flags, &notify);
    zone_iattach(zone, &notify->zone);
    notify->src = src;
    notify->dst = dst;

    INSIST(notify->key == NULL);

    if (key != NULL) {
      notify->key = key;
      key = NULL;
    }

    INSIST(notify->transport == NULL);
    if (transport != NULL) {
      notify->transport = transport;
      transport = NULL;
    }

    ISC_LIST_APPEND(zone->notifysoa.notifies, notify, link);
    result = dns_notify_queue(notify, startup);
    if (result != ISC_R_SUCCESS) {
      dns_notify_destroy(notify, true);
    }
    if (!loggednotify) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_NOTIFY,
              ISC_LOG_INFO,
              "sending notifies (serial %u)", serial);
      loggednotify = true;
    }
  next:
    flags &= ~DNS_NOTIFY_TCP;
    dns_remote_next(&zone->alsonotify, false);
  }
  UNLOCK_ZONE(zone);

  if (notifytype == dns_notifytype_explicit) {
    goto cleanup3;
  }

  /*
   * Process NS RRset to generate notifies.
   */

  dns_rdataset_init(&nsrdset);
  result = dns_db_findrdataset(zonedb, node, version, dns_rdatatype_ns,
             dns_rdatatype_none, 0, &nsrdset, NULL);
  if (result != ISC_R_SUCCESS) {
    goto cleanup3;
  }

  DNS_RDATASET_FOREACH(&nsrdset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&nsrdset, &rdata);

    dns_notify_t *notify = NULL;

    result = dns_rdata_tostruct(&rdata, &ns);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    /*
     * Don't notify the primary server unless explicitly
     * configured to do so.
     */
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NOTIFYTOSOA) &&
        dns_name_compare(&primary, &ns.name) == 0)
    {
      continue;
    }

    if (!loggednotify) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_NOTIFY,
              ISC_LOG_INFO,
              "sending notifies (serial %u)", serial);
      loggednotify = true;
    }

    LOCK_ZONE(zone);
    isqueued = dns_notify_isqueued(
      &zone->notifysoa, dns_rdatatype_soa,
      zone->view->dstport, flags, &ns.name, NULL, NULL, NULL);
    UNLOCK_ZONE(zone);
    if (isqueued) {
      continue;
    }
    dns_notify_create(zone->mctx, dns_rdatatype_soa,
          zone->view->dstport, flags, &notify);
    dns_zone_iattach(zone, &notify->zone);
    dns_name_dup(&ns.name, zone->mctx, &notify->ns);
    LOCK_ZONE(zone);
    ISC_LIST_APPEND(zone->notifysoa.notifies, notify, link);
    UNLOCK_ZONE(zone);
    dns_notify_find_address(notify);
  }
  dns_rdataset_disassociate(&nsrdset);

cleanup3:
  if (dns_name_dynamic(&primary)) {
    dns_name_free(&primary, zone->mctx);
  }
cleanup2:
  dns_db_detachnode(&node);
cleanup1:
  dns_db_closeversion(zonedb, &version, false);
  dns_db_detach(&zonedb);
}

/***
 *** Private
 ***/
static void
create_query(dns_zone_t *zone, dns_rdatatype_t rdtype, dns_name_t *name,
       dns_message_t **messagep) {
  dns_message_t *message = NULL;
  dns_linkedname_t *qname = NULL;
  dns_rdataset_t *qrdataset = NULL;

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTRENDER,
         &message);

  message->opcode = dns_opcode_query;
  message->rdclass = zone->rdclass;

  dns_message_gettempname(message, &qname);

  dns_message_gettemprdataset(message, &qrdataset);

  /*
   * Make question.
   */
  dns_name_clone(name, dns_name(qname));
  dns_rdataset_makequestion(qrdataset, zone->rdclass, rdtype);
  ISC_LIST_APPEND(qname->list, qrdataset, link);
  dns_message_addname(message, qname, DNS_SECTION_QUESTION);

  *messagep = message;
}

static isc_result_t
add_opt(dns_message_t *message, uint16_t udpsize, bool reqnsid,
  bool reqexpire) {
  dns_message_ednsinit(message, 0, udpsize, 0, 0);

  /* Set EDNS options if applicable. */
  if (reqnsid) {
    dns_ednsopt_t option = { .code = DNS_OPT_NSID };
    RETERR(dns_message_ednsaddopt(message, &option));
  }
  if (reqexpire) {
    dns_ednsopt_t option = { .code = DNS_OPT_EXPIRE };
    RETERR(dns_message_ednsaddopt(message, &option));
  }

  return dns_message_setopt(message);
}

/*
 * Called when stub zone update is finished.
 * Update zone refresh, retry, expire values accordingly with
 * SOA received from primary, sync database to file, restart
 * zone management timer.
 */
static void
stub_finish_zone_update(dns_stub_t *stub, isc_time_t now) {
  uint32_t refresh, retry, expire;
  isc_result_t result;
  isc_interval_t i;
  unsigned int soacount;
  dns_zone_t *zone = stub->zone;

  /*
   * Tidy up.
   */
  dns_db_closeversion(stub->db, &stub->version, true);
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
  if (zone->db == NULL) {
    zone_attachdb(zone, stub->db);
  }
  result = zone_get_from_db(zone, zone->db, NULL, &soacount, NULL, NULL,
          &refresh, &retry, &expire, NULL, NULL);
  if (result == ISC_R_SUCCESS && soacount > 0U) {
    zone->refresh = RANGE(refresh, zone->minrefresh,
              zone->maxrefresh);
    zone->retry = RANGE(retry, zone->minretry, zone->maxretry);
    zone->expire = RANGE(expire, zone->refresh + zone->retry,
             DNS_MAX_EXPIRE);
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
  dns_db_detach(&stub->db);

  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
  DNS_ZONE_JITTER_ADD(&now, zone->refresh, &zone->refreshtime);
  isc_interval_set(&i, zone->expire, 0);
  DNS_ZONE_TIME_ADD(&now, zone->expire, &zone->expiretime);

  if (zone->masterfile != NULL) {
    zone_needdump(zone, 0);
  }

  dns__zone_settimer(zone, now);
}

/*
 * Process answers for A and AAAA queries when
 * resolving nameserver addresses for which glue
 * was missing in a previous answer for a NS query.
 */
static void
stub_glue_response(void *arg) {
  dns_request_t *request = (dns_request_t *)arg;
  struct stub_glue_request *sgr = dns_request_getarg(request);
  struct stub_cb_args *cb_args = sgr->args;
  dns_stub_t *stub = cb_args->stub;
  dns_message_t *msg = NULL;
  dns_zone_t *zone = NULL;
  char primary[ISC_SOCKADDR_FORMATSIZE];
  char source[ISC_SOCKADDR_FORMATSIZE];
  uint32_t addr_count, cnamecnt;
  isc_result_t result;
  isc_sockaddr_t curraddr, sourceaddr;
  dns_rdataset_t *addr_rdataset = NULL;
  dns_dbnode_t *node = NULL;

  INSIST(DNS_STUB_VALID(stub));

  zone = stub->zone;

  ENTER;

  LOCK_ZONE(zone);

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    zone_debuglog(zone, __func__, 1, "exiting");
    goto cleanup;
  }

  sourceaddr = zone_addr_tosockaddr(&zone->sourceaddr);
  curraddr = dns_remote_curraddr(&zone->primaries);
  isc_sockaddr_format(&curraddr, primary, sizeof(primary));
  isc_sockaddr_format(&sourceaddr, source, sizeof(source));

  if (dns_request_getresult(request) != ISC_R_SUCCESS) {
    dns_unreachcache_add(zone->view->unreachcache, &curraddr,
             &sourceaddr);
    dns_zone_log(zone, ISC_LOG_INFO,
           "could not refresh stub from primary %s"
           " (source %s): %s",
           primary, source,
           isc_result_totext(dns_request_getresult(request)));
    goto cleanup;
  }

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE,
         &msg);
  result = dns_request_getresponse(request, msg, 0);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: unable to parse response (%s)",
           isc_result_totext(result));
    goto cleanup;
  }

  /*
   * Unexpected opcode.
   */
  if (msg->opcode != dns_opcode_query) {
    char opcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, opcode, sizeof(opcode));
    (void)dns_opcode_totext(msg->opcode, &rb);

    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "unexpected opcode (%.*s) from %s (source %s)",
           (int)rb.used, opcode, primary, source);
    goto cleanup;
  }

  /*
   * Unexpected rcode.
   */
  if (msg->rcode != dns_rcode_noerror) {
    char rcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, rcode, sizeof(rcode));
    (void)dns_rcode_totext(msg->rcode, &rb);

    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "unexpected rcode (%.*s) from %s (source %s)",
           (int)rb.used, rcode, primary, source);
    goto cleanup;
  }

  /*
   * We need complete messages.
   */
  if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0) {
    if (dns_request_usedtcp(request)) {
      dns_zone_log(zone, ISC_LOG_INFO,
             "refreshing stub: truncated TCP "
             "response from primary %s (source %s)",
             primary, source);
    }
    goto cleanup;
  }

  /*
   * If non-auth log.
   */
  if ((msg->flags & DNS_MESSAGEFLAG_AA) == 0) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "non-authoritative answer from "
           "primary %s (source %s)",
           primary, source);
    goto cleanup;
  }

  /*
   * Sanity checks.
   */
  cnamecnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_cname);
  addr_count = message_count(msg, DNS_SECTION_ANSWER,
           sgr->ipv4 ? dns_rdatatype_a
               : dns_rdatatype_aaaa);

  if (cnamecnt != 0) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: unexpected CNAME response "
           "from primary %s (source %s)",
           primary, source);
    goto cleanup;
  }

  if (addr_count == 0) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: no %s records in response "
           "from primary %s (source %s)",
           sgr->ipv4 ? "A" : "AAAA", primary, source);
    goto cleanup;
  }
  /*
   * Extract A or AAAA RRset from message.
   */
  result = dns_message_findname(msg, DNS_SECTION_ANSWER, &sgr->name,
              sgr->ipv4 ? dns_rdatatype_a
            : dns_rdatatype_aaaa,
              dns_rdatatype_none, NULL, &addr_rdataset);
  if (result != ISC_R_SUCCESS) {
    if (result != DNS_R_NXDOMAIN && result != DNS_R_NXRRSET) {
      char namebuf[DNS_NAME_FORMATSIZE];
      dns_name_format(&sgr->name, namebuf, sizeof(namebuf));
      dns_zone_log(
        zone, ISC_LOG_INFO,
        "refreshing stub: dns_message_findname(%s/%s) "
        "failed (%s)",
        namebuf, sgr->ipv4 ? "A" : "AAAA",
        isc_result_totext(result));
    }
    goto cleanup;
  }

  result = dns_db_findnode(stub->db, &sgr->name, true, &node);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "dns_db_findnode() failed: %s",
           isc_result_totext(result));
    goto cleanup;
  }

  result = dns_db_addrdataset(stub->db, node, stub->version, 0,
            addr_rdataset, 0, NULL);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "dns_db_addrdataset() failed: %s",
           isc_result_totext(result));
  }
  dns_db_detachnode(&node);

cleanup:
  if (msg != NULL) {
    dns_message_detach(&msg);
  }

  dns_name_free(&sgr->name, zone->mctx);
  dns_request_destroy(&sgr->request);
  isc_mem_put(zone->mctx, sgr, sizeof(*sgr));

  /* If last request, release all related resources */
  if (atomic_fetch_sub_release(&stub->pending_requests, 1) == 1) {
    isc_mem_put(zone->mctx, cb_args, sizeof(*cb_args));
    stub_finish_zone_update(stub, isc_time_now());
    UNLOCK_ZONE(zone);
    stub->magic = 0;
    dns_zone_idetach(&stub->zone);
    INSIST(stub->db == NULL);
    INSIST(stub->version == NULL);
    isc_mem_put(stub->mctx, stub, sizeof(*stub));
  } else {
    UNLOCK_ZONE(zone);
  }
}

/*
 * Create and send an A or AAAA query to the primary
 * server of the stub zone given.
 */
static isc_result_t
stub_request_nameserver_address(struct stub_cb_args *args, bool ipv4,
        const dns_name_t *name) {
  dns_message_t *message = NULL;
  dns_zone_t *zone;
  isc_result_t result;
  struct stub_glue_request *sgr;
  isc_sockaddr_t curraddr, sourceaddr;

  zone = args->stub->zone;
  sgr = isc_mem_get(zone->mctx, sizeof(*sgr));
  *sgr = (struct stub_glue_request){
    .args = args,
    .name = (dns_name_t)DNS_NAME_INITEMPTY,
    .ipv4 = ipv4,
  };

  dns_name_dup(name, zone->mctx, &sgr->name);

  create_query(zone, ipv4 ? dns_rdatatype_a : dns_rdatatype_aaaa,
         &sgr->name, &message);

  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
    result = add_opt(message, args->udpsize, args->reqnsid, false);
    if (result != ISC_R_SUCCESS) {
      zone_debuglog(zone, __func__, 1,
              "unable to add opt record: %s",
              isc_result_totext(result));
      goto fail;
    }
  }

  atomic_fetch_add_release(&args->stub->pending_requests, 1);

  sourceaddr = zone_addr_tosockaddr(&zone->sourceaddr);
  curraddr = dns_remote_curraddr(&zone->primaries);
  result = dns_request_create(
    zone->view->requestmgr, message, &sourceaddr, &curraddr, NULL,
    NULL, DNS_REQUESTOPT_TCP, args->tsig_key, args->connect_timeout,
    args->timeout, UDP_REQUEST_TIMEOUT, UDP_REQUEST_RETRIES,
    zone->loop, stub_glue_response, sgr, &sgr->request);

  if (result != ISC_R_SUCCESS) {
    uint_fast32_t pr;
    pr = atomic_fetch_sub_release(&args->stub->pending_requests, 1);
    INSIST(pr > 1);
    zone_debuglog(zone, __func__, 1,
            "dns_request_create() failed: %s",
            isc_result_totext(result));
    goto fail;
  }

  dns_message_detach(&message);

  return ISC_R_SUCCESS;

fail:
  dns_name_free(&sgr->name, zone->mctx);
  isc_mem_put(zone->mctx, sgr, sizeof(*sgr));

  if (message != NULL) {
    dns_message_detach(&message);
  }

  return result;
}

static isc_result_t
save_nsrrset(dns_message_t *message, dns_name_t *name,
       struct stub_cb_args *cb_args, dns_db_t *db,
       dns_dbversion_t *version) {
  dns_rdataset_t *nsrdataset = NULL;
  dns_rdataset_t *rdataset = NULL;
  dns_dbnode_t *node = NULL;
  dns_rdata_ns_t ns;
  isc_result_t result;
  bool has_glue = false;

  /*
   * List of NS entries in answer, keep names that will be used
   * to resolve missing A/AAAA glue for each entry.
   */
  dns_namelist_t ns_list;
  ISC_LIST_INIT(ns_list);

  /*
   * Extract NS RRset from message.
   */
  result = dns_message_findname(message, DNS_SECTION_ANSWER, name,
              dns_rdatatype_ns, dns_rdatatype_none,
              NULL, &nsrdataset);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

  /*
   * Add NS rdataset.
   */
  result = dns_db_findnode(db, name, true, &node);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }
  result = dns_db_addrdataset(db, node, version, 0, nsrdataset, 0, NULL);
  dns_db_detachnode(&node);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }
  /*
   * Add glue rdatasets.
   */
  DNS_RDATASET_FOREACH(nsrdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(nsrdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &ns);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    if (!dns_name_issubdomain(&ns.name, name)) {
      continue;
    }
    rdataset = NULL;
    result = dns_message_findname(message, DNS_SECTION_ADDITIONAL,
                &ns.name, dns_rdatatype_aaaa,
                dns_rdatatype_none, NULL,
                &rdataset);
    if (result == ISC_R_SUCCESS) {
      has_glue = true;
      result = dns_db_findnode(db, &ns.name, true, &node);
      if (result != ISC_R_SUCCESS) {
        goto done;
      }
      result = dns_db_addrdataset(db, node, version, 0,
                rdataset, 0, NULL);
      dns_db_detachnode(&node);
      if (result != ISC_R_SUCCESS) {
        goto done;
      }
    }

    rdataset = NULL;
    result = dns_message_findname(
      message, DNS_SECTION_ADDITIONAL, &ns.name,
      dns_rdatatype_a, dns_rdatatype_none, NULL, &rdataset);
    if (result == ISC_R_SUCCESS) {
      has_glue = true;
      result = dns_db_findnode(db, &ns.name, true, &node);
      if (result != ISC_R_SUCCESS) {
        goto done;
      }
      result = dns_db_addrdataset(db, node, version, 0,
                rdataset, 0, NULL);
      dns_db_detachnode(&node);
      if (result != ISC_R_SUCCESS) {
        goto done;
      }
    }

    /*
     * If no glue is found so far, we add the name to the list to
     * resolve the A/AAAA glue later. If any glue is found in any
     * iteration step, this list will be discarded and only the glue
     * provided in this message will be used.
     */
    if (!has_glue && dns_name_issubdomain(&ns.name, name)) {
      dns_linkedname_t *tmp_name;
      tmp_name = isc_mem_get(cb_args->stub->mctx,
                 sizeof(*tmp_name));
      dns_linkedname_init(tmp_name);
      dns_name_dup(&ns.name, cb_args->stub->mctx,
             dns_name(tmp_name));
      ISC_LIST_APPEND(ns_list, tmp_name, link);
    }
  }

  /*
   * If no glue records were found, we attempt to resolve A/AAAA
   * for each NS entry found in the answer.
   */
  if (!has_glue) {
    ISC_LIST_FOREACH(ns_list, ns_name, link) {
      /*
       * Resolve NS IPv4 address/A.
       */
      result = stub_request_nameserver_address(
        cb_args, true, dns_name(ns_name));
      if (result != ISC_R_SUCCESS) {
        goto done;
      }
      /*
       * Resolve NS IPv6 address/AAAA.
       */
      result = stub_request_nameserver_address(
        cb_args, false, dns_name(ns_name));
      if (result != ISC_R_SUCCESS) {
        goto done;
      }
    }
  }

  result = ISC_R_SUCCESS;

done:
  ISC_LIST_FOREACH(ns_list, ns_name, link) {
    ISC_LIST_UNLINK(ns_list, ns_name, link);
    dns_name_free(dns_name(ns_name), cb_args->stub->mctx);
    isc_mem_put(cb_args->stub->mctx, ns_name, sizeof(*ns_name));
  }
  return result;
}

static void
stub_callback(void *arg) {
  dns_request_t *request = (dns_request_t *)arg;
  struct stub_cb_args *cb_args = dns_request_getarg(request);
  dns_stub_t *stub = cb_args->stub;
  dns_message_t *msg = NULL;
  dns_zone_t *zone = NULL;
  char primary[ISC_SOCKADDR_FORMATSIZE];
  char source[ISC_SOCKADDR_FORMATSIZE];
  uint32_t nscnt, cnamecnt;
  isc_result_t result;
  isc_sockaddr_t curraddr, sourceaddr;
  isc_time_t now;
  bool exiting = false;

  INSIST(DNS_STUB_VALID(stub));

  zone = stub->zone;

  ENTER;

  now = isc_time_now();

  LOCK_ZONE(zone);

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    goto exiting;
  }

  sourceaddr = zone_addr_tosockaddr(&zone->sourceaddr);
  curraddr = dns_remote_curraddr(&zone->primaries);
  isc_sockaddr_format(&curraddr, primary, sizeof(primary));
  isc_sockaddr_format(&sourceaddr, source, sizeof(source));

  result = dns_request_getresult(request);
  switch (result) {
  case ISC_R_SUCCESS:
    break;
  case ISC_R_SHUTTINGDOWN:
  case ISC_R_CANCELED:
    goto exiting;
  case ISC_R_TIMEDOUT:
    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      dns_zone_log(zone, ISC_LOG_DEBUG(1),
             "refreshing stub: timeout retrying "
             "without EDNS primary %s (source %s)",
             primary, source);
      goto same_primary;
    }
    FALLTHROUGH;
  default:
    dns_unreachcache_add(zone->view->unreachcache, &curraddr,
             &sourceaddr);
    dns_zone_log(zone, ISC_LOG_INFO,
           "could not refresh stub from primary "
           "%s (source %s): %s",
           primary, source, isc_result_totext(result));
    goto next_primary;
  }

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE,
         &msg);

  result = dns_request_getresponse(request, msg, 0);
  if (result != ISC_R_SUCCESS) {
    goto next_primary;
  }

  /*
   * Unexpected opcode.
   */
  if (msg->opcode != dns_opcode_query) {
    char opcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, opcode, sizeof(opcode));
    (void)dns_opcode_totext(msg->opcode, &rb);

    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "unexpected opcode (%.*s) from %s (source %s)",
           (int)rb.used, opcode, primary, source);
    goto next_primary;
  }

  /*
   * Unexpected rcode.
   */
  if (msg->rcode != dns_rcode_noerror) {
    char rcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, rcode, sizeof(rcode));
    (void)dns_rcode_totext(msg->rcode, &rb);

    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS) &&
        (msg->rcode == dns_rcode_servfail ||
         msg->rcode == dns_rcode_notimp ||
         (msg->rcode == dns_rcode_formerr && msg->opt == NULL)))
    {
      dns_zone_log(zone, ISC_LOG_DEBUG(1),
             "refreshing stub: rcode (%.*s) retrying "
             "without EDNS primary %s (source %s)",
             (int)rb.used, rcode, primary, source);
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      goto same_primary;
    }

    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "unexpected rcode (%.*s) from %s (source %s)",
           (int)rb.used, rcode, primary, source);
    goto next_primary;
  }

  /*
   * We need complete messages.
   */
  if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0) {
    if (dns_request_usedtcp(request)) {
      dns_zone_log(zone, ISC_LOG_INFO,
             "refreshing stub: truncated TCP "
             "response from primary %s (source %s)",
             primary, source);
      goto next_primary;
    }
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEVC);
    goto same_primary;
  }

  /*
   * If non-auth log and next primary.
   */
  if ((msg->flags & DNS_MESSAGEFLAG_AA) == 0) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: "
           "non-authoritative answer from "
           "primary %s (source %s)",
           primary, source);
    goto next_primary;
  }

  /*
   * Sanity checks.
   */
  cnamecnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_cname);
  nscnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_ns);

  if (cnamecnt != 0) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: unexpected CNAME response "
           "from primary %s (source %s)",
           primary, source);
    goto next_primary;
  }

  if (nscnt == 0) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: no NS records in response "
           "from primary %s (source %s)",
           primary, source);
    goto next_primary;
  }

  atomic_fetch_add(&stub->pending_requests, 1);

  /*
   * Save answer.
   */
  result = save_nsrrset(msg, &zone->origin, cb_args, stub->db,
            stub->version);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "refreshing stub: unable to save NS records "
           "from primary %s (source %s)",
           primary, source);
    goto next_primary;
  }

  dns_message_detach(&msg);
  dns_request_destroy(&zone->request);

  /*
   * Check to see if there are no outstanding requests and
   * finish off if that is so.
   */
  if (atomic_fetch_sub(&stub->pending_requests, 1) == 1) {
    isc_mem_put(zone->mctx, cb_args, sizeof(*cb_args));
    stub_finish_zone_update(stub, now);
    goto free_stub;
  }

  UNLOCK_ZONE(zone);
  return;

exiting:
  zone_debuglog(zone, __func__, 1, "exiting");
  exiting = true;

next_primary:
  isc_mem_put(zone->mctx, cb_args, sizeof(*cb_args));
  if (stub->version != NULL) {
    dns_db_closeversion(stub->db, &stub->version, false);
  }
  if (stub->db != NULL) {
    dns_db_detach(&stub->db);
  }
  if (msg != NULL) {
    dns_message_detach(&msg);
  }
  dns_request_destroy(&zone->request);
  /*
   * Skip to next failed / untried primary.
   */
  dns_remote_next(&zone->primaries, true);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOEDNS);
  if (exiting || dns_remote_done(&zone->primaries)) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
    dns__zone_settimer(zone, now);
    goto free_stub;
  }
  queue_soa_query(zone);
  goto free_stub;

same_primary:
  isc_mem_put(zone->mctx, cb_args, sizeof(*cb_args));
  if (msg != NULL) {
    dns_message_detach(&msg);
  }
  dns_request_destroy(&zone->request);
  ns_query(zone, NULL, stub);
  UNLOCK_ZONE(zone);
  return;

free_stub:
  UNLOCK_ZONE(zone);
  stub->magic = 0;
  dns_zone_idetach(&stub->zone);
  INSIST(stub->db == NULL);
  INSIST(stub->version == NULL);
  isc_mem_put(stub->mctx, stub, sizeof(*stub));
}

/*
 * Get the EDNS EXPIRE option from the response and if it exists trim
 * expire to be not more than it.
 */
static void
get_edns_expire(dns_zone_t *zone, dns_message_t *message, uint32_t *expirep) {
  isc_result_t result;
  uint32_t expire;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  isc_buffer_t optbuf;
  uint16_t optcode;
  uint16_t optlen;

  REQUIRE(expirep != NULL);
  REQUIRE(message != NULL);

  if (message->opt == NULL) {
    return;
  }

  result = dns_rdataset_first(message->opt);
  if (result == ISC_R_SUCCESS) {
    dns_rdataset_current(message->opt, &rdata);
    isc_buffer_init(&optbuf, rdata.data, rdata.length);
    isc_buffer_add(&optbuf, rdata.length);
    while (isc_buffer_remaininglength(&optbuf) >= 4) {
      optcode = isc_buffer_getuint16(&optbuf);
      optlen = isc_buffer_getuint16(&optbuf);
      /*
       * A EDNS EXPIRE response has a length of 4.
       */
      if (optcode != DNS_OPT_EXPIRE || optlen != 4) {
        isc_buffer_forward(&optbuf, optlen);
        continue;
      }
      expire = isc_buffer_getuint32(&optbuf);
      dns_zone_log(zone, ISC_LOG_DEBUG(1),
             "got EDNS EXPIRE of %u", expire);
      /*
       * Trim *expirep?
       */
      if (expire < *expirep) {
        *expirep = expire;
      }
      break;
    }
  }
}

/*
 * Set the file modification time zone->expire seconds before expiretime.
 */
static void
setmodtime(dns_zone_t *zone, isc_time_t *expiretime) {
  isc_result_t result;
  isc_time_t when;
  isc_interval_t i;

  isc_interval_set(&i, zone->expire, 0);
  result = isc_time_subtract(expiretime, &i, &when);
  if (result != ISC_R_SUCCESS) {
    return;
  }

  result = ISC_R_FAILURE;
  if (zone->journal != NULL) {
    result = isc_file_settime(zone->journal, &when);
  }
  if (result == ISC_R_SUCCESS &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
  {
    result = isc_file_settime(zone->masterfile, &when);
  } else if (result != ISC_R_SUCCESS) {
    result = isc_file_settime(zone->masterfile, &when);
  }

  /*
   * Someone removed the file from underneath us!
   */
  if (result == ISC_R_FILENOTFOUND) {
    zone_needdump(zone, DNS_DUMP_DELAY);
  } else if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "refresh: could not set "
           "file modification time of '%s': %s",
           zone->masterfile, isc_result_totext(result));
  }
}

/*
 * An SOA query has finished (successfully or not).
 */
static void
refresh_callback(void *arg) {
  dns_request_t *request = (dns_request_t *)arg;
  dns_zone_t *zone = dns_request_getarg(request);
  dns_message_t *msg = NULL;
  uint32_t soacnt, cnamecnt, soacount, nscount;
  isc_time_t now;
  char primary[ISC_SOCKADDR_FORMATSIZE];
  char source[ISC_SOCKADDR_FORMATSIZE];
  dns_rdataset_t *rdataset = NULL;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_rdata_soa_t soa;
  isc_result_t result;
  const isc_result_t eresult = dns_request_getresult(request);
  isc_sockaddr_t curraddr, sourceaddr;
  uint32_t serial, oldserial = 0;
  bool do_queue_xfrin = false;

  INSIST(DNS_ZONE_VALID(zone));

  ENTER;

  if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_DEBUG(3),
            "refresh: request result: %s",
            isc_result_totext(eresult));
  }

  now = isc_time_now();

  LOCK_ZONE(zone);

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    goto exiting;
  }

  /*
   * If timeout, log and try the next primary
   */
  sourceaddr = zone_addr_tosockaddr(&zone->sourceaddr);
  curraddr = dns_remote_curraddr(&zone->primaries);
  isc_sockaddr_format(&curraddr, primary, sizeof(primary));
  isc_sockaddr_format(&sourceaddr, source, sizeof(source));

  switch (eresult) {
  case ISC_R_SUCCESS:
    break;
  case ISC_R_SHUTTINGDOWN:
  case ISC_R_CANCELED:
    goto exiting;
  case ISC_R_TIMEDOUT:
    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_DEBUG(1),
              "refresh: timeout retrying without EDNS "
              "primary %s (source %s)",
              primary, source);
      goto same_primary;
    } else if (!dns_request_usedtcp(request)) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO,
              "refresh: retry limit for "
              "primary %s exceeded (source %s)",
              primary, source);
      /* Try with secondary with TCP. */
      if ((zone->type == dns_zone_secondary ||
           zone->type == dns_zone_mirror ||
           zone->type == dns_zone_redirect) &&
          DNS_ZONE_OPTION(zone, DNS_ZONEOPT_TRYTCPREFRESH))
      {
        if (dns_unreachcache_find(
              zone->view->unreachcache, &curraddr,
              &sourceaddr) != ISC_R_SUCCESS)
        {
          DNS_ZONE_SETFLAG(
            zone,
            DNS_ZONEFLG_SOABEFOREAXFR);
          goto tcp_transfer;
        }
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_DEBUG(1),
                "refresh: skipped tcp fallback "
                "as primary %s (source %s) is "
                "unreachable (cached)",
                primary, source);
      }
      goto next_primary;
    }
    FALLTHROUGH;
  default:
    result = eresult;
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: failure trying primary "
            "%s (source %s): %s",
            primary, source, isc_result_totext(result));
    goto next_primary;
  }

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE,
         &msg);
  result = dns_request_getresponse(request, msg, 0);
  if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: failure trying primary "
            "%s (source %s): %s",
            primary, source, isc_result_totext(result));
    goto next_primary;
  }

  /*
   * Unexpected opcode.
   */
  if (msg->opcode != dns_opcode_query) {
    char opcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, opcode, sizeof(opcode));
    (void)dns_opcode_totext(msg->opcode, &rb);

    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: "
            "unexpected opcode (%.*s) from %s (source %s)",
            (int)rb.used, opcode, primary, source);
    goto next_primary;
  }

  /*
   * Unexpected rcode.
   */
  if (msg->rcode != dns_rcode_noerror) {
    char rcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, rcode, sizeof(rcode));
    (void)dns_rcode_totext(msg->rcode, &rb);

    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS) &&
        (msg->rcode == dns_rcode_servfail ||
         msg->rcode == dns_rcode_notimp ||
         (msg->rcode == dns_rcode_formerr && msg->opt == NULL)))
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_DEBUG(1),
              "refresh: rcode (%.*s) retrying without "
              "EDNS primary %s (source %s)",
              (int)rb.used, rcode, primary, source);
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      goto same_primary;
    }
    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS) &&
        msg->rcode == dns_rcode_badvers)
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_DEBUG(1),
              "refresh: rcode (%.*s) retrying without "
              "EDNS EXPIRE OPTION primary %s "
              "(source %s)",
              (int)rb.used, rcode, primary, source);
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      goto same_primary;
    }
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: unexpected rcode (%.*s) from "
            "primary %s (source %s)",
            (int)rb.used, rcode, primary, source);
    /*
     * Perhaps AXFR/IXFR is allowed even if SOA queries aren't.
     */
    if (msg->rcode == dns_rcode_refused &&
        (zone->type == dns_zone_secondary ||
         zone->type == dns_zone_mirror ||
         zone->type == dns_zone_redirect))
    {
      goto tcp_transfer;
    }
    goto next_primary;
  }

  /*
   * If truncated punt to zone transfer which will query again.
   */
  if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0) {
    if (zone->type == dns_zone_secondary ||
        zone->type == dns_zone_mirror ||
        zone->type == dns_zone_redirect)
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO,
              "refresh: truncated UDP answer, "
              "initiating TCP zone xfer "
              "for primary %s (source %s)",
              primary, source);
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR);
      goto tcp_transfer;
    } else {
      INSIST(zone->type == dns_zone_stub);
      if (dns_request_usedtcp(request)) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_INFO,
                "refresh: truncated TCP response "
                "from primary %s (source %s)",
                primary, source);
        goto next_primary;
      }
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEVC);
      goto same_primary;
    }
  }

  /*
   * If non-auth, log and try the next primary
   */
  if ((msg->flags & DNS_MESSAGEFLAG_AA) == 0) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: non-authoritative answer from "
            "primary %s (source %s)",
            primary, source);
    goto next_primary;
  }

  cnamecnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_cname);
  soacnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_soa);
  nscount = message_count(msg, DNS_SECTION_AUTHORITY, dns_rdatatype_ns);
  soacount = message_count(msg, DNS_SECTION_AUTHORITY, dns_rdatatype_soa);

  /*
   * There should not be a CNAME record at top of zone.
   */
  if (cnamecnt != 0) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: CNAME at top of zone "
            "in primary %s (source %s)",
            primary, source);
    goto next_primary;
  }

  /*
   * If referral, log and try the next primary;
   */
  if (soacnt == 0 && soacount == 0 && nscount != 0) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: referral response "
            "from primary %s (source %s)",
            primary, source);
    goto next_primary;
  }

  /*
   * If nodata, log and try the next primary;
   */
  if (soacnt == 0 && (nscount == 0 || soacount != 0)) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: NODATA response "
            "from primary %s (source %s)",
            primary, source);
    goto next_primary;
  }

  /*
   * Only one soa at top of zone.
   */
  if (soacnt != 1) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: answer SOA count (%d) != 1 "
            "from primary %s (source %s)",
            soacnt, primary, source);
    goto next_primary;
  }

  /*
   * Extract serial
   */
  rdataset = NULL;
  result = dns_message_findname(msg, DNS_SECTION_ANSWER, &zone->origin,
              dns_rdatatype_soa, dns_rdatatype_none,
              NULL, &rdataset);
  if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: unable to get SOA record "
            "from primary %s (source %s)",
            primary, source);
    goto next_primary;
  }

  result = dns_rdataset_first(rdataset);
  if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refresh: dns_rdataset_first() failed");
    goto next_primary;
  }

  dns_rdataset_current(rdataset, &rdata);
  result = dns_rdata_tostruct(&rdata, &soa);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  serial = soa.serial;
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
    unsigned int dbsoacount;
    result = zone_get_from_db(zone, zone->db, NULL, &dbsoacount,
            NULL, &oldserial, NULL, NULL, NULL,
            NULL, NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    RUNTIME_CHECK(dbsoacount > 0U);
    zone_debuglogc(zone, DNS_LOGCATEGORY_XFER_IN, __func__, 1,
             "serial: new %u, old %u", serial, oldserial);
  } else {
    zone_debuglogc(zone, DNS_LOGCATEGORY_XFER_IN, __func__, 1,
             "serial: new %u, old not loaded", serial);
  }

  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) ||
      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER) ||
      isc_serial_gt(serial, oldserial))
  {
    if (dns_unreachcache_find(zone->view->unreachcache, &curraddr,
            &sourceaddr) == ISC_R_SUCCESS)
    {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO,
              "refresh: skipping %s as primary %s "
              "(source %s) is unreachable (cached)",
              (zone->type == dns_zone_secondary ||
               zone->type == dns_zone_mirror ||
               zone->type == dns_zone_redirect)
                ? "zone transfer"
                : "NS query",
              primary, source);
      goto next_primary;
    }
  tcp_transfer:
    dns_request_destroy(&zone->request);
    if (zone->type == dns_zone_secondary ||
        zone->type == dns_zone_mirror ||
        zone->type == dns_zone_redirect)
    {
      do_queue_xfrin = true;
    } else {
      INSIST(zone->type == dns_zone_stub);
      ns_query(zone, rdataset, NULL);
    }
    if (msg != NULL) {
      dns_message_detach(&msg);
    }
  } else if (isc_serial_eq(soa.serial, oldserial)) {
    isc_time_t expiretime;
    uint32_t expire;

    /*
     * Compute the new expire time based on this response.
     */
    expire = zone->expire;
    get_edns_expire(zone, msg, &expire);
    DNS_ZONE_TIME_ADD(&now, expire, &expiretime);

    /*
     * Has the expire time improved?
     */
    if (isc_time_compare(&expiretime, &zone->expiretime) > 0) {
      zone->expiretime = expiretime;
      if (zone->masterfile != NULL) {
        setmodtime(zone, &expiretime);
      }
    }

    DNS_ZONE_JITTER_ADD(&now, zone->refresh, &zone->refreshtime);
    dns_remote_mark(&zone->primaries, true);
    goto next_primary;
  } else {
    if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_MULTIMASTER)) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO,
              "serial number (%u) "
              "received from primary %s < ours (%u)",
              soa.serial, primary, oldserial);
    } else {
      zone_debuglogc(zone, DNS_LOGCATEGORY_XFER_IN, __func__,
               1, "ahead");
    }
    dns_remote_mark(&zone->primaries, true);
    goto next_primary;
  }
  if (msg != NULL) {
    dns_message_detach(&msg);
  }
  goto detach;

next_primary:
  if (msg != NULL) {
    dns_message_detach(&msg);
  }
  dns_request_destroy(&zone->request);
  /*
   * Skip to next failed / untried primary.
   */
  dns_remote_next(&zone->primaries, true);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOEDNS);
  if (dns_remote_done(&zone->primaries)) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDREFRESH)) {
      DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
      zone->refreshtime = now;
    }
    dns__zone_settimer(zone, now);
    goto detach;
  }

  queue_soa_query(zone);
  goto detach;

exiting:
  /*
   * We can get here not only during shutdown, but also when the refresh
   * is canceled during reconfiguration. In that case, make sure to clear
   * the DNS_ZONEFLG_REFRESH flag so that future zone refreshes don't get
   * stuck, and make sure a new refresh attempt is made again soon after
   * the reconfiguration is complete.
   */
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
  zone->refreshtime = now;
  dns__zone_settimer(zone, now);

  dns_request_destroy(&zone->request);
  goto detach;

same_primary:
  if (msg != NULL) {
    dns_message_detach(&msg);
  }
  dns_request_destroy(&zone->request);
  queue_soa_query(zone);

detach:
  if (do_queue_xfrin) {
    /* Shows in the statistics channel the duration of the step. */
    zone->xfrintime = isc_time_now();
  }
  UNLOCK_ZONE(zone);
  if (do_queue_xfrin) {
    queue_xfrin(zone);
  }
  dns_zone_idetach(&zone);
  return;
}

struct soaquery {
  dns_zone_t *zone;
  isc_rlevent_t *rlevent;
};

static void
queue_soa_query(dns_zone_t *zone) {
  isc_result_t result;
  struct soaquery *sq = NULL;

  ENTER;
  /*
   * Locked by caller
   */
  REQUIRE(LOCKED_ZONE(zone));

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    cancel_refresh(zone);
    return;
  }

  sq = isc_mem_get(zone->mctx, sizeof(*sq));
  *sq = (struct soaquery){ .zone = NULL };

  /* Shows in the statistics channel the duration of the current step. */
  zone->xfrintime = isc_time_now();

  /*
   * Attach so that we won't clean up until the event is delivered.
   */
  zone_iattach(zone, &sq->zone);
  result = isc_ratelimiter_enqueue(dns_g_zonemgr->refreshrl, zone->loop,
           soa_query, sq, &sq->rlevent);
  if (result != ISC_R_SUCCESS) {
    zone_idetach(&sq->zone);
    isc_mem_put(zone->mctx, sq, sizeof(*sq));
    cancel_refresh(zone);
  }
}

static void
soa_query(void *arg) {
  struct soaquery *sq = (struct soaquery *)arg;
  dns_zone_t *zone = sq->zone;
  isc_result_t result = ISC_R_FAILURE;
  dns_message_t *message = NULL;
  isc_netaddr_t primaryip;
  dns_tsigkey_t *key = NULL;
  dns_transport_t *transport = NULL;
  uint32_t options;
  bool cancel = true;
  bool have_xfrsource = false, reqnsid, reqexpire;
  uint16_t udpsize = SEND_BUFFER_SIZE;
  isc_sockaddr_t curraddr, sourceaddr, remotesource;
  bool do_queue_xfrin = false;

  REQUIRE(DNS_ZONE_VALID(zone));

  ENTER;

  LOCK_ZONE(zone);
  if (sq->rlevent->canceled || DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) ||
      zone->view->requestmgr == NULL)
  {
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
      cancel = false;
    }
    goto cleanup;
  }

again:
  dns_zone_logc(
    zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_DEBUG(3),
    "soa_query: remote server current address index %d count %d",
    zone->primaries.curraddr, zone->primaries.addrcnt);
  INSIST(dns_remote_count(&zone->primaries) > 0);
  INSIST(!dns_remote_done(&zone->primaries));

  remotesource = dns_remote_sourceaddr(&zone->primaries);
  sourceaddr = zone_addr_tosockaddr(&zone->sourceaddr);
  curraddr = dns_remote_curraddr(&zone->primaries);
  isc_netaddr_fromsockaddr(&primaryip, &curraddr);

  if (isc_sockaddr_disabled(&curraddr)) {
    goto skip_primary;
  }

  /*
   * First, look for a tsig key in the primaries statement, then
   * try for a server key.
   */
  if (dns_remote_keyname(&zone->primaries) != NULL) {
    dns_view_t *view = dns_zone_getview(zone);
    dns_name_t *keyname = dns_remote_keyname(&zone->primaries);
    result = dns_view_gettsig(view, keyname, &key);
    if (result != ISC_R_SUCCESS) {
      char namebuf[DNS_NAME_FORMATSIZE];
      dns_name_format(keyname, namebuf, sizeof(namebuf));
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_ERROR, "unable to find key: %s",
              namebuf);
      goto skip_primary;
    }
  }
  if (key == NULL) {
    result = dns_view_getpeertsig(zone->view, &primaryip, &key);
    if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
      char addrbuf[ISC_NETADDR_FORMATSIZE];
      isc_netaddr_format(&primaryip, addrbuf,
             sizeof(addrbuf));
      dns_zone_logc(
        zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_ERROR,
        "unable to find TSIG key for %s", addrbuf);
      goto skip_primary;
    }
  }

  if (dns_remote_tlsname(&zone->primaries) != NULL) {
    dns_view_t *view = dns_zone_getview(zone);
    dns_name_t *tlsname = dns_remote_tlsname(&zone->primaries);
    result = dns_view_gettransport(view, DNS_TRANSPORT_TLS, tlsname,
                 &transport);
    if (result != ISC_R_SUCCESS) {
      char namebuf[DNS_NAME_FORMATSIZE];
      dns_name_format(tlsname, namebuf, sizeof(namebuf));
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_ERROR,
              "unable to find TLS configuration: %s",
              namebuf);
      goto skip_primary;
    }
  }

  options = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEVC) ? DNS_REQUESTOPT_TCP
               : 0;
  reqnsid = zone->view->requestnsid;
  reqexpire = zone->requestexpire;
  if (zone->view->peers != NULL) {
    dns_peer_t *peer = NULL;
    bool edns, usetcp;
    result = dns_peerlist_peerbyaddr(zone->view->peers, &primaryip,
             &peer);
    if (result == ISC_R_SUCCESS) {
      result = dns_peer_getsupportedns(peer, &edns);
      if (result == ISC_R_SUCCESS && !edns) {
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      }
      result = dns_peer_gettransfersource(peer, &sourceaddr);
      if (result == ISC_R_SUCCESS) {
        have_xfrsource = true;
      }
      udpsize = dns_view_getudpsize(zone->view);
      (void)dns_peer_getudpsize(peer, &udpsize);
      (void)dns_peer_getrequestnsid(peer, &reqnsid);
      (void)dns_peer_getrequestexpire(peer, &reqexpire);
      result = dns_peer_getforcetcp(peer, &usetcp);
      if (result == ISC_R_SUCCESS && usetcp) {
        options |= DNS_REQUESTOPT_TCP;
      }
    }
  }

  switch (isc_sockaddr_pf(&curraddr)) {
  case PF_INET:
    if (!have_xfrsource) {
      isc_sockaddr_t any;
      isc_sockaddr_any(&any);

      sourceaddr = remotesource;
      if (isc_sockaddr_equal(&sourceaddr, &any)) {
        sourceaddr = zone_addr4_tosockaddr(
          &zone->xfrsource4);
      }
    }
    break;
  case PF_INET6:
    if (!have_xfrsource) {
      isc_sockaddr_t any;
      isc_sockaddr_any6(&any);

      sourceaddr = remotesource;
      if (isc_sockaddr_equal(&sourceaddr, &any)) {
        sourceaddr = zone_addr6_tosockaddr(
          &zone->xfrsource6);
      }
    }
    break;
  default:
    CLEANUP(ISC_R_NOTIMPLEMENTED);
  }
  zone->sourceaddr = zone_addr_fromsockaddr(&sourceaddr);

  /*
   * FIXME(OS): This is a bit hackish, but it enforces the SOA query to go
   * through the XFR channel instead of doing dns_request that doesn't
   * have DoT support yet.
   */
  if (transport != NULL) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR);
    do_queue_xfrin = true;
    cancel = false;
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  create_query(zone, dns_rdatatype_soa, &zone->origin, &message);

  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
    result = add_opt(message, udpsize, reqnsid, reqexpire);
    if (result != ISC_R_SUCCESS) {
      zone_debuglogc(zone, DNS_LOGCATEGORY_XFER_IN, __func__,
               1, "unable to add opt record: %s",
               isc_result_totext(result));
    }
  }

  zone_iattach(zone, &(dns_zone_t *){ NULL });
  const unsigned int connect_timeout = isc_nm_getprimariestimeout() /
               MS_PER_SEC;
  result = dns_request_create(
    zone->view->requestmgr, message, &sourceaddr, &curraddr, NULL,
    NULL, options, key, connect_timeout, TCP_REQUEST_TIMEOUT,
    UDP_REQUEST_TIMEOUT, UDP_REQUEST_RETRIES, zone->loop,
    refresh_callback, zone, &zone->request);
  if (result != ISC_R_SUCCESS) {
    zone_idetach(&(dns_zone_t *){ zone });
    zone_debuglogc(zone, DNS_LOGCATEGORY_XFER_IN, __func__, 1,
             "dns_request_create() failed: %s",
             isc_result_totext(result));
    goto skip_primary;
  } else {
    /* Shows in the statistics channel the duration of the query. */
    zone->xfrintime = isc_time_now();

    if (isc_sockaddr_pf(&curraddr) == PF_INET) {
      dns__zone_stats_increment(
        zone, dns_zonestatscounter_soaoutv4);
    } else {
      dns__zone_stats_increment(
        zone, dns_zonestatscounter_soaoutv6);
    }
  }
  cancel = false;
cleanup:
  if (transport != NULL) {
    dns_transport_detach(&transport);
  }
  if (key != NULL) {
    dns_tsigkey_detach(&key);
  }
  if (result != ISC_R_SUCCESS) {
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
  }
  if (message != NULL) {
    dns_message_detach(&message);
  }
  if (cancel) {
    cancel_refresh(zone);
  }
  if (do_queue_xfrin) {
    /* Shows in the statistics channel the duration of the step. */
    zone->xfrintime = isc_time_now();
  }
  UNLOCK_ZONE(zone);
  if (do_queue_xfrin) {
    queue_xfrin(zone);
  }
  isc_rlevent_free(&sq->rlevent);
  isc_mem_put(zone->mctx, sq, sizeof(*sq));
  dns_zone_idetach(&zone);
  return;

skip_primary:
  if (transport != NULL) {
    dns_transport_detach(&transport);
  }
  if (key != NULL) {
    dns_tsigkey_detach(&key);
  }
  if (message != NULL) {
    dns_message_detach(&message);
  }
  /*
   * Skip to next failed / untried primary.
   */
  dns_remote_next(&zone->primaries, true);
  if (!dns_remote_done(&zone->primaries)) {
    goto again;
  }
  dns_remote_reset(&zone->primaries, false);
  goto cleanup;
}

static void
ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset, dns_stub_t *stub) {
  isc_result_t result;
  dns_message_t *message = NULL;
  isc_netaddr_t primaryip;
  dns_tsigkey_t *key = NULL;
  dns_dbnode_t *node = NULL;
  bool have_xfrsource = false;
  bool reqnsid;
  uint16_t udpsize = SEND_BUFFER_SIZE;
  isc_sockaddr_t curraddr, sourceaddr, remotesource;
  struct stub_cb_args *cb_args = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  REQUIRE((soardataset != NULL && stub == NULL) ||
    (soardataset == NULL && stub != NULL));
  REQUIRE(stub == NULL || DNS_STUB_VALID(stub));

  ENTER;

  if (stub == NULL) {
    stub = isc_mem_get(zone->mctx, sizeof(*stub));
    stub->magic = STUB_MAGIC;
    stub->mctx = zone->mctx;
    stub->zone = NULL;
    stub->db = NULL;
    stub->version = NULL;
    atomic_init(&stub->pending_requests, 0);

    /*
     * Attach so that the zone won't disappear from under us.
     */
    zone_iattach(zone, &stub->zone);

    /*
     * If a db exists we will update it, otherwise we create a
     * new one and attach it to the zone once we have the NS
     * RRset and glue.
     */
    ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
    if (zone->db != NULL) {
      dns_db_attach(zone->db, &stub->db);
      ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
    } else {
      ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

      INSIST(zone->db_argc >= 1);
      result = dns_db_create(zone->mctx, zone->db_argv[0],
                 &zone->origin, dns_dbtype_stub,
                 zone->rdclass, zone->db_argc - 1,
                 zone->db_argv + 1, &stub->db);
      if (result != ISC_R_SUCCESS) {
        dns_zone_log(zone, ISC_LOG_ERROR,
               "refreshing stub: "
               "could not create "
               "database: %s",
               isc_result_totext(result));
        goto cleanup;
      }
      dns_db_setmaxrrperset(stub->db, zone->maxrrperset);
      dns_db_setmaxtypepername(stub->db,
             zone->maxtypepername);
    }

    result = dns_db_newversion(stub->db, &stub->version);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_INFO,
             "refreshing stub: "
             "dns_db_newversion() failed: %s",
             isc_result_totext(result));
      goto cleanup;
    }

    /*
     * Update SOA record.
     */
    result = dns_db_findnode(stub->db, &zone->origin, true, &node);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_INFO,
             "refreshing stub: "
             "dns_db_findnode() failed: %s",
             isc_result_totext(result));
      goto cleanup;
    }

    result = dns_db_addrdataset(stub->db, node, stub->version, 0,
              soardataset, 0, NULL);
    dns_db_detachnode(&node);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_INFO,
             "refreshing stub: "
             "dns_db_addrdataset() failed: %s",
             isc_result_totext(result));
      goto cleanup;
    }
  }

  /*
   * XXX Optimisation: Create message when zone is setup and reuse.
   */
  create_query(zone, dns_rdatatype_ns, &zone->origin, &message);

  INSIST(dns_remote_count(&zone->primaries) > 0);
  INSIST(!dns_remote_done(&zone->primaries));

  remotesource = dns_remote_sourceaddr(&zone->primaries);
  sourceaddr = zone_addr_tosockaddr(&zone->sourceaddr);
  curraddr = dns_remote_curraddr(&zone->primaries);
  isc_netaddr_fromsockaddr(&primaryip, &curraddr);
  /*
   * First, look for a tsig key in the primaries statement, then
   * try for a server key.
   */
  if (dns_remote_keyname(&zone->primaries) != NULL) {
    dns_view_t *view = dns_zone_getview(zone);
    dns_name_t *keyname = dns_remote_keyname(&zone->primaries);
    result = dns_view_gettsig(view, keyname, &key);
    if (result != ISC_R_SUCCESS) {
      char namebuf[DNS_NAME_FORMATSIZE];
      dns_name_format(keyname, namebuf, sizeof(namebuf));
      dns_zone_log(zone, ISC_LOG_ERROR,
             "unable to find key: %s", namebuf);
    }
  }
  if (key == NULL) {
    (void)dns_view_getpeertsig(zone->view, &primaryip, &key);
  }

  /* FIXME(OS): Do we need the transport here too? Most probably yes */

  reqnsid = zone->view->requestnsid;
  if (zone->view->peers != NULL) {
    dns_peer_t *peer = NULL;
    bool edns;
    result = dns_peerlist_peerbyaddr(zone->view->peers, &primaryip,
             &peer);
    if (result == ISC_R_SUCCESS) {
      result = dns_peer_getsupportedns(peer, &edns);
      if (result == ISC_R_SUCCESS && !edns) {
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
      }
      result = dns_peer_gettransfersource(peer, &sourceaddr);
      if (result == ISC_R_SUCCESS) {
        have_xfrsource = true;
      }
      udpsize = dns_view_getudpsize(zone->view);
      (void)dns_peer_getudpsize(peer, &udpsize);
      (void)dns_peer_getrequestnsid(peer, &reqnsid);
    }
  }
  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
    result = add_opt(message, udpsize, reqnsid, false);
    if (result != ISC_R_SUCCESS) {
      zone_debuglog(zone, __func__, 1,
              "unable to add opt record: %s",
              isc_result_totext(result));
    }
  }

  /*
   * Always use TCP so that we shouldn't truncate in additional section.
   */
  switch (isc_sockaddr_pf(&curraddr)) {
  case PF_INET:
    if (!have_xfrsource) {
      isc_sockaddr_t any;
      isc_sockaddr_any(&any);

      sourceaddr = remotesource;
      if (isc_sockaddr_equal(&sourceaddr, &any)) {
        sourceaddr = zone_addr4_tosockaddr(
          &zone->xfrsource4);
      }
    }
    break;
  case PF_INET6:
    if (!have_xfrsource) {
      isc_sockaddr_t any;
      isc_sockaddr_any6(&any);

      sourceaddr = remotesource;
      if (isc_sockaddr_equal(&sourceaddr, &any)) {
        sourceaddr = zone_addr6_tosockaddr(
          &zone->xfrsource6);
      }
    }
    break;
  default:
    result = ISC_R_NOTIMPLEMENTED;
    POST(result);
    goto cleanup;
  }
  zone->sourceaddr = zone_addr_fromsockaddr(&sourceaddr);

  /*
   * Save request parameters so we can reuse them later on
   * for resolving missing glue A/AAAA records.
   */
  cb_args = isc_mem_get(zone->mctx, sizeof(*cb_args));
  cb_args->stub = stub;
  cb_args->tsig_key = key;
  cb_args->udpsize = udpsize;
  cb_args->connect_timeout = isc_nm_getprimariestimeout() / MS_PER_SEC;
  cb_args->timeout = TCP_REQUEST_TIMEOUT;
  cb_args->reqnsid = reqnsid;

  result = dns_request_create(
    zone->view->requestmgr, message, &sourceaddr, &curraddr, NULL,
    NULL, DNS_REQUESTOPT_TCP, key, cb_args->connect_timeout,
    cb_args->timeout, UDP_REQUEST_TIMEOUT, UDP_REQUEST_RETRIES,
    zone->loop, stub_callback, cb_args, &zone->request);
  if (result != ISC_R_SUCCESS) {
    zone_debuglog(zone, __func__, 1,
            "dns_request_create() failed: %s",
            isc_result_totext(result));
    goto cleanup;
  }
  dns_message_detach(&message);
  goto unlock;

cleanup:
  cancel_refresh(zone);
  stub->magic = 0;
  if (stub->version != NULL) {
    dns_db_closeversion(stub->db, &stub->version, false);
  }
  if (stub->db != NULL) {
    dns_db_detach(&stub->db);
  }
  if (stub->zone != NULL) {
    zone_idetach(&stub->zone);
  }
  if (cb_args != NULL) {
    isc_mem_put(zone->mctx, cb_args, sizeof(*cb_args));
  }
  isc_mem_put(stub->mctx, stub, sizeof(*stub));
  if (message != NULL) {
    dns_message_detach(&message);
  }
unlock:
  if (key != NULL) {
    dns_tsigkey_detach(&key);
  }
  return;
}

/*
 * Shut the zone down.
 */
static void
zone_shutdown(void *arg) {
  dns_zone_t *zone = (dns_zone_t *)arg;
  bool free_needed, linked = false;
  dns_zone_t *raw = NULL, *secure = NULL;
  dns_view_t *view = NULL, *prev_view = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));
  INSIST(isc_refcount_current(&zone->references) == 0);

  zone_debuglog(zone, __func__, 3, "shutting down");

  /*
   * If we were waiting for xfrin quota, step out of
   * the queue.
   * A zone without an event loop cannot be waiting for transfer quota.
   */
  if (zone->loop != NULL) {
    RWLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_write);
    if (zone->statelist == &dns_g_zonemgr->waiting_for_xfrin) {
      ISC_LIST_UNLINK(dns_g_zonemgr->waiting_for_xfrin, zone,
          statelink);
      linked = true;
      zone->statelist = NULL;
    }
    if (zone->statelist == &dns_g_zonemgr->xfrin_in_progress) {
      ISC_LIST_UNLINK(dns_g_zonemgr->xfrin_in_progress, zone,
          statelink);
      zone->statelist = NULL;
      dns__zonemgr_resume_xfrs(dns_g_zonemgr, false);
    }
    RWUNLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_write);
  }

  /*
   * In loop context, no locking required.  See dns__zone_xfrdone().
   */
  if (zone->xfr != NULL) {
    /* The final detach will happen in dns__zone_xfrdone() */
    dns_xfrin_shutdown(zone->xfr);
  }

  /* Detach the zone configuration pointer */
  dns_zone_setcfg(zone, NULL, NULL);

  zone_clear_inline_sync(zone);

  LOCK_ZONE(zone);
  INSIST(zone != zone->raw);

  /*
   * Detach the views early, we don't need them anymore.  However, we need
   * to detach them outside of the zone lock to break the lock loop
   * between view, adb and zone locks.
   */
  view = zone->view;
  zone->view = NULL;
  prev_view = zone->prev_view;
  zone->prev_view = NULL;

  if (linked) {
    isc_refcount_decrement(&zone->irefs);
  }
  if (zone->request != NULL) {
    dns_request_cancel(zone->request);
  }

  if (zone->loadctx != NULL) {
    dns_loadctx_cancel(zone->loadctx);
  }

  if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) ||
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
  {
    if (zone->dumpctx != NULL) {
      dns_dumpctx_cancel(zone->dumpctx);
    }
  }

  checkds_cancel(zone);

  dns_notify_cancel(&zone->notifysoa);
  dns_notify_cancel(&zone->notifycds);

  dns__zone_forward_cancel(zone);

  if (zone->timer != NULL) {
    isc_refcount_decrement(&zone->irefs);
    isc_timer_destroy(&zone->timer);
  }

  /*
   * We have now canceled everything set the flag to allow
   * dns__zone_free_check() to succeed. We must not unlock between
   * setting this flag and calling dns__zone_free_check().
   */
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_SHUTDOWN);
  free_needed = dns__zone_free_check(zone);
  /*
   * If a dump is in progress for the secure zone, defer detaching from
   * the raw zone as it may prevent the unsigned serial number from being
   * stored in the raw-format dump of the secure zone.  In this scenario,
   * dump_done() takes care of cleaning up the zone->raw reference.
   */
  if (dns__zone_inline_secure(zone) &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
  {
    raw = zone->raw;
    zone->raw = NULL;
  }
  if (dns__zone_inline_raw(zone)) {
    secure = zone->secure;
    zone->secure = NULL;
  }
  UNLOCK_ZONE(zone);

  if (view != NULL) {
    dns_view_weakdetach(&view);
  }
  if (prev_view != NULL) {
    dns_view_weakdetach(&prev_view);
  }

  if (raw != NULL) {
    dns_zone_detach(&raw);
  }
  if (secure != NULL) {
    dns_zone_idetach(&secure);
  }
  if (free_needed) {
    dns__zone_free(zone);
  }
}

static void
zone_timer(void *arg) {
  dns_zone_t *zone = (dns_zone_t *)arg;

  REQUIRE(DNS_ZONE_VALID(zone));

  zone_maintenance(zone);
}

static void
zone_timer_stop(dns_zone_t *zone) {
  zone_debuglog(zone, __func__, 10, "stop zone timer");
  if (zone->timer != NULL) {
    isc_timer_stop(zone->timer);
  }
}

static void
zone_timer_set(dns_zone_t *zone, isc_time_t *next, isc_time_t *now) {
  isc_interval_t interval;

  if (isc_time_compare(next, now) <= 0) {
    isc_interval_set(&interval, 0, 0);
  } else {
    isc_time_subtract(next, now, &interval);
  }

  if (zone->loop == NULL) {
    zone_debuglog(zone, __func__, 10, "zone is not managed");
  } else if (zone->timer == NULL) {
    isc_refcount_increment0(&zone->irefs);
    isc_timer_create(zone->loop, zone_timer, zone, &zone->timer);
  }
  if (zone->timer != NULL) {
    isc_timer_start(zone->timer, isc_timertype_once, &interval);
  }
}

static void
zone__settimer(void *arg) {
  zone_settimer_t *data = arg;
  dns_zone_t *zone = data->zone;
  isc_time_t now = data->now;
  isc_time_t next;
  bool free_needed = false;

  REQUIRE(DNS_ZONE_VALID(zone));
  ENTER;

  LOCK_ZONE(zone);
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    goto free;
  }
  isc_time_settoepoch(&next);

  switch (zone->type) {
  case dns_zone_redirect:
    if (dns_remote_addresses(&zone->primaries) != NULL) {
      goto treat_as_secondary;
    }
    FALLTHROUGH;
  case dns_zone_primary:
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) ||
        DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDSTARTUPNOTIFY))
    {
      next = zone->notifytime;
    }
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
        !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
    {
      INSIST(!isc_time_isepoch(&zone->dumptime));
      next = time_min(next, zone->dumptime);
    }
    if (zone->type == dns_zone_redirect) {
      break;
    }
    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESHING)) {
      next = time_min(next, zone->refreshkeytime);
    }
    next = time_min(next, zone->resigntime);
    next = time_min(next, zone->keywarntime);
    next = time_min(next, zone->signingtime);
    if (zone_inline_sync_pending(zone)) {
      next = time_min(next, now);
    }
    if (zone_maintenance_request_pending(zone)) {
      next = time_min(next, now);
    }
    next = time_min(next, zone->nsec3chaintime);
    break;

  case dns_zone_secondary:
  case dns_zone_mirror:
  treat_as_secondary:
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) ||
        DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDSTARTUPNOTIFY))
    {
      next = zone->notifytime;
    }
    FALLTHROUGH;
  case dns_zone_stub:
    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH) &&
        !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOPRIMARIES) &&
        !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADING) &&
        !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADPENDING))
    {
      next = time_min(next, zone->refreshtime);
    }
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
      next = time_min(next, zone->expiretime);
    }
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
        !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
    {
      INSIST(!isc_time_isepoch(&zone->dumptime));
      next = time_min(next, zone->dumptime);
    }
    break;

  case dns_zone_key:
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
        !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING))
    {
      INSIST(!isc_time_isepoch(&zone->dumptime));
      next = time_min(next, zone->dumptime);
    }
    if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESHING)) {
      next = time_min(next, zone->refreshkeytime);
    }
    break;

  default:
    break;
  }

  if (isc_time_isepoch(&next)) {
    zone_timer_stop(zone);
  } else {
    zone_timer_set(zone, &next, &now);
  }

free:
  isc_mem_put(zone->mctx, data, sizeof(*data));
  isc_refcount_decrement(&zone->irefs);
  free_needed = dns__zone_free_check(zone);
  UNLOCK_ZONE(zone);
  if (free_needed) {
    dns__zone_free(zone);
  }
}

void
dns__zone_settimer(dns_zone_t *zone, isc_time_t now) {
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    return;
  }

  zone_settimer_t *arg = isc_mem_get(zone->mctx, sizeof(*arg));
  *arg = (zone_settimer_t){
    .zone = zone,
    .now = now,
  };
  isc_refcount_increment0(&zone->irefs);
  isc_async_run(zone->loop, zone__settimer, arg);
}

static void
cancel_refresh(dns_zone_t *zone) {
  /*
   * 'zone' locked by caller.
   */

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));

  ENTER;

  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
  dns__zone_settimer(zone, isc_time_now());
}

isc_result_t
dns_zone_notifyreceive(dns_zone_t *zone, isc_sockaddr_t *from,
           isc_sockaddr_t *to, dns_message_t *msg) {
  unsigned int i;
  dns_rdata_soa_t soa;
  dns_rdataset_t *rdataset = NULL;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  isc_result_t result;
  char fromtext[ISC_SOCKADDR_FORMATSIZE];
  int match = 0;
  isc_netaddr_t netaddr;
  uint32_t serial = 0;
  bool have_serial = false;
  dns_tsigkey_t *tsigkey;
  const dns_name_t *tsig;

  REQUIRE(DNS_ZONE_VALID(zone));

  /*
   * If type != T_SOA return DNS_R_NOTIMP.  We don't yet support
   * ROLLOVER.
   *
   * SOA: RFC1996
   * Check that 'from' is a valid notify source, (zone->primaries).
   *  Return DNS_R_REFUSED if not.
   *
   * If the notify message contains a serial number check it
   * against the zones serial and return if <= current serial
   *
   * If a refresh check is progress, if so just record the
   * fact we received a NOTIFY and from where and return.
   * We will perform a new refresh check when the current one
   * completes. Return ISC_R_SUCCESS.
   *
   * Otherwise initiate a refresh check using 'from' as the
   * first address to check.  Return ISC_R_SUCCESS.
   */

  isc_sockaddr_format(from, fromtext, sizeof(fromtext));

  /*
   * Notify messages are processed by the raw zone.
   */
  LOCK_ZONE(zone);
  INSIST(zone != zone->raw);
  if (dns__zone_inline_secure(zone)) {
    result = dns_zone_notifyreceive(zone->raw, from, to, msg);
    UNLOCK_ZONE(zone);
    return result;
  }
  /*
   *  We only handle NOTIFY (SOA) at the present.
   */
  if (isc_sockaddr_pf(from) == PF_INET) {
    dns__zone_stats_increment(zone,
            dns_zonestatscounter_notifyinv4);
  } else {
    dns__zone_stats_increment(zone,
            dns_zonestatscounter_notifyinv6);
  }
  if (msg->counts[DNS_SECTION_QUESTION] == 0 ||
      dns_message_findname(msg, DNS_SECTION_QUESTION, &zone->origin,
         dns_rdatatype_soa, dns_rdatatype_none, NULL,
         NULL) != ISC_R_SUCCESS)
  {
    UNLOCK_ZONE(zone);
    if (msg->counts[DNS_SECTION_QUESTION] == 0) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_NOTICE,
              "NOTIFY with no question "
              "section from: %s",
              fromtext);
      return DNS_R_FORMERR;
    }
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_NOTICE,
            "NOTIFY zone does not match");
    return DNS_R_NOTIMP;
  }

  /*
   * If we are a primary zone just succeed.
   */
  if (zone->type == dns_zone_primary) {
    UNLOCK_ZONE(zone);
    return ISC_R_SUCCESS;
  }

  isc_netaddr_fromsockaddr(&netaddr, from);
  for (i = 0; i < dns_remote_count(&zone->primaries); i++) {
    isc_sockaddr_t sockaddr = dns_remote_addr(&zone->primaries, i);
    if (isc_sockaddr_eqaddr(from, &sockaddr)) {
      break;
    }
    if (zone->view->aclenv->match_mapped &&
        IN6_IS_ADDR_V4MAPPED(&from->type.sin6.sin6_addr) &&
        isc_sockaddr_pf(&sockaddr) == AF_INET)
    {
      isc_netaddr_t na1, na2;
      isc_netaddr_fromv4mapped(&na1, &netaddr);
      isc_netaddr_fromsockaddr(&na2, &sockaddr);
      if (isc_netaddr_equal(&na1, &na2)) {
        break;
      }
    }
  }

  /*
   * Accept notify requests from non primaries if they are on
   * 'zone->notifysoa.notify_acl'.
   */
  tsigkey = dns_message_gettsigkey(msg);
  tsig = dns_tsigkey_identity(tsigkey);
  if (i >= dns_remote_count(&zone->primaries) &&
      zone->notifysoa.notify_acl != NULL &&
      (dns_acl_match(&netaddr, tsig, zone->notifysoa.notify_acl,
         zone->view->aclenv, &match,
         NULL) == ISC_R_SUCCESS) &&
      match > 0)
  {
    /* Accept notify. */
  } else if (i >= dns_remote_count(&zone->primaries)) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "refused notify from non-primary: %s", fromtext);
    dns__zone_stats_increment(zone, dns_zonestatscounter_notifyrej);
    UNLOCK_ZONE(zone);
    return DNS_R_REFUSED;
  }

  /*
   * If the zone is loaded and there are answers check the serial
   * to see if we need to do a refresh.
   */
  if (msg->counts[DNS_SECTION_ANSWER] > 0 &&
      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
  {
    result = dns_message_findname(
      msg, DNS_SECTION_ANSWER, &zone->origin,
      dns_rdatatype_soa, dns_rdatatype_none, NULL, &rdataset);
    if (result == ISC_R_SUCCESS) {
      result = dns_rdataset_first(rdataset);
    }
    if (result == ISC_R_SUCCESS) {
      uint32_t oldserial;
      unsigned int soacount;

      dns_rdataset_current(rdataset, &rdata);
      result = dns_rdata_tostruct(&rdata, &soa);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      serial = soa.serial;
      have_serial = true;
      /*
       * The following should safely be performed without DB
       * lock and succeed in this context.
       */
      result = zone_get_from_db(zone, zone->db, NULL,
              &soacount, NULL, &oldserial,
              NULL, NULL, NULL, NULL, NULL);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      RUNTIME_CHECK(soacount > 0U);
      if (isc_serial_le(serial, oldserial)) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_INFO,
                "notify from %s: "
                "zone is up to date",
                fromtext);
        UNLOCK_ZONE(zone);
        return ISC_R_SUCCESS;
      }
    }
  }

  /*
   * If we got this far and there was a refresh in progress just
   * let it complete.  Record where we got the notify from so we
   * can perform a refresh check when the current one completes
   */
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH)) {
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
    UNLOCK_ZONE(zone);
    if (have_serial) {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO,
              "notify from %s: "
              "serial %u: refresh in progress, "
              "refresh check queued",
              fromtext, serial);
    } else {
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO,
              "notify from %s: "
              "refresh in progress, "
              "refresh check queued",
              fromtext);
    }
    return ISC_R_SUCCESS;
  }
  if (have_serial) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "notify from %s: serial %u", fromtext, serial);
  } else {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "notify from %s: no serial", fromtext);
  }
  UNLOCK_ZONE(zone);

  if (to != NULL) {
    dns_unreachcache_remove(zone->view->unreachcache, from, to);
  }
  dns_zone_refresh(zone);
  return ISC_R_SUCCESS;
}

void
dns_zone_logv(dns_zone_t *zone, isc_logcategory_t category, int level,
        const char *prefix, const char *fmt, va_list ap) {
  char message[4096];
  char namebuf[1024];
  const char *zstr;

  REQUIRE(DNS_ZONE_VALID(zone));

  if (!isc_log_wouldlog(level)) {
    return;
  }

  zone_namerd_tostr(zone, namebuf, sizeof(namebuf));
  vsnprintf(message, sizeof(message), fmt, ap);

  switch (zone->type) {
  case dns_zone_key:
    zstr = "managed-keys-zone";
    break;
  case dns_zone_redirect:
    zstr = "redirect-zone";
    break;
  default:
    zstr = "zone ";
  }

  isc_log_write(category, DNS_LOGMODULE_ZONE, level, "%s%s%s%s: %s",
          prefix != NULL ? prefix : "", prefix != NULL ? ": " : "",
          zstr, namebuf, message);
}

void
dns_zone_logc(dns_zone_t *zone, isc_logcategory_t category, int level,
        const char *fmt, ...) {
  va_list ap;

  va_start(ap, fmt);
  dns_zone_logv(zone, category, level, NULL, fmt, ap);
  va_end(ap);
}

void
dns_zone_log(dns_zone_t *zone, int level, const char *fmt, ...) {
  va_list ap;

  va_start(ap, fmt);
  dns_zone_logv(zone, DNS_LOGCATEGORY_GENERAL, level, NULL, fmt, ap);
  va_end(ap);
}

static void
zone_debuglogc(dns_zone_t *zone, isc_logcategory_t category, const char *me,
         int debuglevel, const char *fmt, ...) {
  int level = ISC_LOG_DEBUG(debuglevel);
  va_list ap;

  va_start(ap, fmt);
  dns_zone_logv(zone, category, level, me, fmt, ap);
  va_end(ap);
}

static void
zone_debuglog(dns_zone_t *zone, const char *me, int debuglevel, const char *fmt,
        ...) {
  int level = ISC_LOG_DEBUG(debuglevel);
  va_list ap;

  va_start(ap, fmt);
  dns_zone_logv(zone, DNS_LOGCATEGORY_GENERAL, level, me, fmt, ap);
  va_end(ap);
}

static void
dnssec_log(dns_zone_t *zone, int level, const char *fmt, ...) {
  va_list ap;

  va_start(ap, fmt);
  dns_zone_logv(zone, DNS_LOGCATEGORY_DNSSEC, level, NULL, fmt, ap);
  va_end(ap);
}

static int
message_count(dns_message_t *msg, dns_section_t section, dns_rdatatype_t type) {
  int count = 0;

  MSG_SECTION_FOREACH(msg, section, name) {
    ISC_LIST_FOREACH_REV(name->list, curr, link) {
      if (curr->type == type) {
        count++;
      }
    }
  }

  return count;
}

const char *
dns_zonetype_name(dns_zonetype_t type) {
  switch (type) {
  case dns_zone_none:
    return "none";
  case dns_zone_primary:
    return "primary";
  case dns_zone_secondary:
    return "secondary";
  case dns_zone_mirror:
    return "mirror";
  case dns_zone_stub:
    return "stub";
  case dns_zone_staticstub:
    return "static-stub";
  case dns_zone_key:
    return "key";
  case dns_zone_dlz:
    return "dlz";
  case dns_zone_redirect:
    return "redirect";
  default:
    return "unknown";
  }
}

dns_zonetype_t
dns_zone_getredirecttype(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(zone->type == dns_zone_redirect);

  return dns_remote_addresses(&zone->primaries) == NULL
           ? dns_zone_primary
           : dns_zone_secondary;
}

dns_notifyctx_t *
dns__zone_getnotifyctx(dns_zone_t *zone, dns_rdatatype_t type) {
  REQUIRE(DNS_ZONE_VALID(zone));

  switch (type) {
  case dns_rdatatype_soa:
    return &zone->notifysoa;
  case dns_rdatatype_cds:
    return &zone->notifycds;
  default:
    UNREACHABLE();
  }
  return NULL;
}

void
dns__zone_stats_increment(dns_zone_t *zone, isc_statscounter_t counter) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  inc_stats(zone, counter);
}

void
dns__zone_lock(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  LOCK_ZONE(zone);
}

void
dns__zone_unlock(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  UNLOCK_ZONE(zone);
}

bool
dns__zone_locked(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  return LOCKED_ZONE(zone);
}

bool
dns__zone_loaded(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  return DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) != 0;
}

bool
dns__zone_exiting(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));
  return DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) != 0;
}

static void
update_log_cb(void *arg, dns_zone_t *zone, int level, const char *message) {
  UNUSED(arg);
  dns_zone_log(zone, level, "%s", message);
}

static isc_result_t
dnskey_inuse(dns_zone_t *zone, dns_rdata_t *rdata, isc_mem_t *mctx,
       dns_dnsseckeylist_t *keylist, bool *inuse) {
  isc_result_t result;
  dst_key_t *dstkey = NULL;

  result = dns_dnssec_keyfromrdata(dns_zone_getorigin(zone), rdata, mctx,
           &dstkey);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "dns_dnssec_keyfromrdata() failed: %s",
           isc_result_totext(result));
    return result;
  }

  ISC_LIST_FOREACH(*keylist, k, link) {
    if (dst_key_pubcompare(k->key, dstkey, false)) {
      *inuse = true;
      break;
    }
  }

  dst_key_free(&dstkey);
  return ISC_R_SUCCESS;
}

static isc_result_t
cdnskey_inuse(dns_zone_t *zone, dns_rdata_t *rdata,
        dns_dnsseckeylist_t *keylist, bool *inuse) {
  isc_result_t result;
  dns_rdata_cdnskey_t cdnskey;

  result = dns_rdata_tostruct(rdata, &cdnskey);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "dns_rdata_tostruct(cdnskey) failed: %s",
           isc_result_totext(result));
    return result;
  }

  ISC_LIST_FOREACH(*keylist, k, link) {
    dns_rdata_t cdnskeyrdata = DNS_RDATA_INIT;
    unsigned char keybuf[DNS_RDATA_MAXLENGTH];

    result = dns_dnssec_make_dnskey(k->key, keybuf, sizeof(keybuf),
            &cdnskeyrdata);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "dns_dnssec_make_dnskey() failed: %s",
             isc_result_totext(result));
      return result;
    }

    cdnskeyrdata.type = dns_rdatatype_cdnskey;
    if (dns_rdata_compare(rdata, &cdnskeyrdata) == 0) {
      *inuse = true;
      break;
    }
  }

  return ISC_R_SUCCESS;
}

static isc_result_t
cds_inuse(dns_zone_t *zone, dns_rdata_t *rdata, dns_dnsseckeylist_t *keylist,
    bool *inuse) {
  isc_result_t result;
  dns_rdata_ds_t cds;

  result = dns_rdata_tostruct(rdata, &cds);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "dns_rdata_tostruct(cds) failed: %s",
           isc_result_totext(result));
    return result;
  }

  ISC_LIST_FOREACH(*keylist, k, link) {
    dns_rdata_t dnskey = DNS_RDATA_INIT;
    dns_rdata_t cdsrdata = DNS_RDATA_INIT;
    unsigned char keybuf[DNS_RDATA_MAXLENGTH];
    unsigned char cdsbuf[DNS_DS_BUFFERSIZE];

    if (dst_key_id(k->key) != cds.key_tag ||
        dst_algorithm_tosecalg(dst_key_alg(k->key)) !=
          cds.algorithm)
    {
      continue;
    }
    result = dns_dnssec_make_dnskey(k->key, keybuf, sizeof(keybuf),
            &dnskey);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "dns_dnssec_make_dnskey() failed: %s",
             isc_result_totext(result));
      return result;
    }
    result = dns_ds_buildrdata(dns_zone_getorigin(zone), &dnskey,
             cds.digest_type, cdsbuf,
             sizeof(cdsbuf), &cdsrdata);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "dns_ds_buildrdata(keytag=%hu, algo=%d, "
             "digest=%d) failed: %s",
             cds.key_tag, cds.algorithm,
             cds.digest_type,
             isc_result_totext(result));
      return result;
    }

    cdsrdata.type = dns_rdatatype_cds;
    if (dns_rdata_compare(rdata, &cdsrdata) == 0) {
      *inuse = true;
      break;
    }
  }

  return ISC_R_SUCCESS;
}

isc_result_t
dns_zone_dnskey_inuse(dns_zone_t *zone, dns_rdata_t *rdata, bool *inuse) {
  dns_dnsseckeylist_t keylist;
  isc_result_t result = ISC_R_SUCCESS;
  isc_stdtime_t now = isc_stdtime_now();
  isc_mem_t *mctx;
  dns_kasp_t *kasp;
  dns_keystorelist_t *keystores;
  const char *keydir;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(dns_rdatatype_iskeymaterial(rdata->type));

  mctx = zone->mctx;

  ISC_LIST_INIT(keylist);

  *inuse = false;

  kasp = dns_zone_getkasp(zone);
  keydir = dns_zone_getkeydirectory(zone);
  keystores = dns_zone_getkeystores(zone);

  if (kasp == NULL) {
    return ISC_R_SUCCESS;
  }

  dns_zone_lock_keyfiles(zone);
  result = dns_dnssec_findmatchingkeys(dns_zone_getorigin(zone), kasp,
               keydir, keystores, now, false,
               mctx, &keylist);
  dns_zone_unlock_keyfiles(zone);
  if (result == ISC_R_NOTFOUND) {
    return ISC_R_SUCCESS;
  } else if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "dns_dnssec_findmatchingkeys() failed: %s",
           isc_result_totext(result));
    return result;
  }

  switch (rdata->type) {
  case dns_rdatatype_dnskey:
    result = dnskey_inuse(zone, rdata, mctx, &keylist, inuse);
    break;
  case dns_rdatatype_cdnskey:
    result = cdnskey_inuse(zone, rdata, &keylist, inuse);
    break;
  case dns_rdatatype_cds:
    result = cds_inuse(zone, rdata, &keylist, inuse);
    break;
  default:
    UNREACHABLE();
    break;
  }

  ISC_LIST_FOREACH(keylist, key, link) {
    ISC_LIST_UNLINK(keylist, key, link);
    dns_dnsseckey_destroy(mctx, &key);
  }
  return result;
}

static isc_result_t
sync_secure_journal(dns_zone_t *zone, dns_zone_t *raw, dns_journal_t *journal,
        uint32_t start, uint32_t end, dns_difftuple_t **soatuplep,
        dns_diff_t *diff) {
  isc_result_t result;
  dns_diff_t pending;
  dns_difftuple_t *tuple = NULL;
  dns_diffop_t op = DNS_DIFFOP_ADD;
  int n_soa = 0;

  REQUIRE(soatuplep != NULL);

  if (start == end) {
    return DNS_R_UNCHANGED;
  }

  dns_diff_init(diff->mctx, &pending);

  CHECK(dns_journal_iter_init(journal, start, end, NULL));
  for (result = dns_journal_first_rr(journal); result == ISC_R_SUCCESS;
       result = dns_journal_next_rr(journal))
  {
    dns_name_t *name = NULL;
    uint32_t ttl;
    dns_rdata_t *rdata = NULL;
    dns_journal_current_rr(journal, &name, &ttl, &rdata);

    if (rdata->type == dns_rdatatype_soa) {
      n_soa++;
      if (n_soa == 2) {
        /*
         * Save the latest raw SOA record.
         */
        if (*soatuplep != NULL) {
          dns_difftuple_free(soatuplep);
        }
        dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD,
                 name, ttl, rdata,
                 soatuplep);
      }
      if (n_soa == 3) {
        n_soa = 1;
      }
      continue;
    }

    /* Sanity. */
    if (n_soa == 0) {
      dns_zone_log(raw, ISC_LOG_ERROR,
             "corrupt journal file: '%s'\n",
             raw->journal);
      CLEANUP(ISC_R_FAILURE);
    }

    if (zone->privatetype != 0 && rdata->type == zone->privatetype)
    {
      continue;
    }

    /*
     * Skip DNSSEC records that BIND maintains with inline-signing.
     */
    if (rdata->type == dns_rdatatype_nsec ||
        rdata->type == dns_rdatatype_rrsig ||
        rdata->type == dns_rdatatype_nsec3 ||
        rdata->type == dns_rdatatype_nsec3param)
    {
      continue;
    }
    /*
     * Allow DNSKEY, CDNSKEY, CDS because users should be able to
     * update the zone with these records from a different provider,
     * but skip records that are under our control.
     */
    if (dns_rdatatype_iskeymaterial(rdata->type)) {
      bool inuse = false;
      isc_result_t r = dns_zone_dnskey_inuse(zone, rdata,
                     &inuse);
      if (r == ISC_R_SUCCESS && inuse) {
        continue;
      }
    }

    op = (n_soa == 1) ? DNS_DIFFOP_DEL : DNS_DIFFOP_ADD;

    dns_difftuple_create(diff->mctx, op, name, ttl, rdata, &tuple);
    dns_diff_append(&pending, &tuple);
  }
  if (result == ISC_R_NOMORE) {
    result = ISC_R_SUCCESS;
  }

cleanup:
  dns_diff_appendlistminimal(diff, &pending);
  return result;
}

/*
 * Filter the key material preserving TTL changes.  If kasp in effect honour the
 * existing ttl.  The lists returned by sync_secure_db/dns_db_diffx should be
 * DNSSEC RRset order so we can process 'del' and 'add' in parallel rather than
 * searching for TTL only changes first and processing them, then checking the
 * 'in use' status on a subsequent pass.
 */

static void
filter_keymaterial(dns_zone_t *zone, dns_difftuplelist_t *del,
       dns_difftuplelist_t *add, bool kasp, dns_ttl_t ttl) {
  dns_difftuple_t *deltuple = ISC_LIST_HEAD(*del);
  dns_difftuple_t *addtuple = ISC_LIST_HEAD(*add);
  isc_result_t result;

  while (deltuple != NULL || addtuple != NULL) {
    dns_difftuple_t *delnext = NULL, *addnext = NULL;
    bool inuse = false;
    if (deltuple != NULL) {
      delnext = ISC_LIST_NEXT(deltuple, link);
    }
    if (addtuple != NULL) {
      addnext = ISC_LIST_NEXT(addtuple, link);
    }
    if (deltuple != NULL && addtuple != NULL) {
      int n = dns_rdata_compare(&deltuple->rdata,
              &addtuple->rdata);
      if (n == 0) {
        /*
         * If the rdata is equal then the only
         * difference will be a TTL change.
         */
        if (kasp) {
          /* TTL is managed by dnssec-policy */
          ISC_LIST_UNLINK(*del, deltuple, link);
          dns_difftuple_free(&deltuple);
          ISC_LIST_UNLINK(*add, addtuple, link);
          dns_difftuple_free(&addtuple);
        }
        deltuple = delnext;
        addtuple = addnext;
        continue;
      }
      if (n < 0) {
        goto checkdel;
      }
      goto checkadd;
    } else if (deltuple != NULL) {
    checkdel:
      result = dns_zone_dnskey_inuse(zone, &deltuple->rdata,
                   &inuse);
      if (result == ISC_R_SUCCESS && inuse) {
        ISC_LIST_UNLINK(*del, deltuple, link);
        dns_difftuple_free(&deltuple);
      }
      deltuple = delnext;
    } else {
    checkadd:
      result = dns_zone_dnskey_inuse(zone, &addtuple->rdata,
                   &inuse);
      if (result == ISC_R_SUCCESS && inuse) {
        ISC_LIST_UNLINK(*add, addtuple, link);
        dns_difftuple_free(&addtuple);
      } else if (kasp) {
        addtuple->ttl = ttl;
      }
      addtuple = addnext;
    }
  }
}

static isc_result_t
sync_secure_db(dns_zone_t *seczone, dns_zone_t *raw, dns_db_t *secdb,
         dns_dbversion_t *secver, dns_difftuple_t **soatuple,
         dns_diff_t *diff) {
  isc_result_t result;
  dns_db_t *rawdb = NULL;
  dns_dbversion_t *rawver = NULL;
  dns_difftuple_t *oldtuple = NULL, *newtuple = NULL;
  dns_rdata_soa_t oldsoa, newsoa;
  dns_difftuplelist_t add = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t del = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t keyadd = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t keydel = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t ckeyadd = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t ckeydel = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t cdsadd = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t cdsdel = ISC_LIST_INITIALIZER;
  dns_kasp_t *kasp = NULL;
  dns_ttl_t keyttl = 0, ckeyttl = 0, cdsttl = 0;

  REQUIRE(DNS_ZONE_VALID(seczone));
  REQUIRE(soatuple != NULL && *soatuple == NULL);

  if (!seczone->sourceserialset) {
    return DNS_R_UNCHANGED;
  }

  dns_db_attach(raw->db, &rawdb);
  dns_db_currentversion(rawdb, &rawver);
  result = dns_db_diffx(diff, rawdb, rawver, secdb, secver, NULL);
  dns_db_closeversion(rawdb, &rawver, false);
  dns_db_detach(&rawdb);

  if (result != ISC_R_SUCCESS) {
    return result;
  }

  /*
   * If kasp is in effect honour the existing DNSKEY, CDNSKEY and CDS
   * TTLs.
   */
  kasp = seczone->kasp;
  if (kasp != NULL) {
    dns_rdataset_t rdataset;
    dns_dbnode_t *node = NULL;
    dns_ttl_t ttl = dns_kasp_dnskeyttl(kasp);

    dns_rdataset_init(&rdataset);

    result = dns_db_getoriginnode(secdb, &node);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    result = dns_db_findrdataset(
      secdb, node, secver, dns_rdatatype_dnskey,
      dns_rdatatype_none, 0, &rdataset, NULL);
    keyttl = (result == ISC_R_SUCCESS) ? rdataset.ttl : ttl;
    dns_rdataset_cleanup(&rdataset);

    result = dns_db_findrdataset(
      secdb, node, secver, dns_rdatatype_cdnskey,
      dns_rdatatype_none, 0, &rdataset, NULL);
    ckeyttl = (result == ISC_R_SUCCESS) ? rdataset.ttl : ttl;
    dns_rdataset_cleanup(&rdataset);

    result = dns_db_findrdataset(
      secdb, node, secver, dns_rdatatype_cds,
      dns_rdatatype_none, 0, &rdataset, NULL);
    cdsttl = (result == ISC_R_SUCCESS) ? rdataset.ttl : ttl;
    dns_rdataset_cleanup(&rdataset);
    dns_db_detachnode(&node);
  }

  ISC_LIST_FOREACH(diff->tuples, tuple, link) {
    dns_difftuplelist_t *al = &add, *dl = &del;

    /*
     * Skip private records that BIND maintains with inline-signing.
     */
    if (seczone->privatetype != 0 &&
        tuple->rdata.type == seczone->privatetype)
    {
      dns_diff_unlink(diff, tuple);
      dns_difftuple_free(&tuple);
      continue;
    }

    /*
     * Skip DNSSEC records that BIND maintains with inline-signing.
     */
    if (tuple->rdata.type == dns_rdatatype_nsec ||
        tuple->rdata.type == dns_rdatatype_rrsig ||
        tuple->rdata.type == dns_rdatatype_nsec3 ||
        tuple->rdata.type == dns_rdatatype_nsec3param)
    {
      dns_diff_unlink(diff, tuple);
      dns_difftuple_free(&tuple);
      continue;
    }

    /*
     * Apex DNSKEY, CDNSKEY and CDS need special processing so
     * split them out.
     */
    if (dns_rdatatype_iskeymaterial(tuple->rdata.type) &&
        dns_name_equal(&tuple->name, &seczone->origin))
    {
      switch (tuple->rdata.type) {
      case dns_rdatatype_dnskey:
        al = &keyadd;
        dl = &keydel;
        break;
      case dns_rdatatype_cdnskey:
        al = &ckeyadd;
        dl = &ckeydel;
        break;
      case dns_rdatatype_cds:
        al = &cdsadd;
        dl = &cdsdel;
        break;
      default:
        UNREACHABLE();
      }
    }

    if (tuple->rdata.type == dns_rdatatype_soa) {
      if (tuple->op == DNS_DIFFOP_DEL) {
        INSIST(oldtuple == NULL);
        oldtuple = tuple;
      }
      if (tuple->op == DNS_DIFFOP_ADD) {
        INSIST(newtuple == NULL);
        newtuple = tuple;
      }
    }

    /*
     * Split into deletions and additions.
     */
    dns_diff_unlink(diff, tuple);
    switch (tuple->op) {
    case DNS_DIFFOP_DEL:
    case DNS_DIFFOP_DELRESIGN:
      ISC_LIST_APPEND(*dl, tuple, link);
      break;
    case DNS_DIFFOP_ADD:
    case DNS_DIFFOP_ADDRESIGN:
      ISC_LIST_APPEND(*al, tuple, link);
      break;
    default:
      UNREACHABLE();
    }
  }

  if (oldtuple != NULL && newtuple != NULL) {
    result = dns_rdata_tostruct(&oldtuple->rdata, &oldsoa);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    result = dns_rdata_tostruct(&newtuple->rdata, &newsoa);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    /*
     * If the SOA records are the same except for the serial
     * remove them from the diff.
     */
    if (oldtuple->ttl == newtuple->ttl &&
        oldsoa.refresh == newsoa.refresh &&
        oldsoa.retry == newsoa.retry &&
        oldsoa.minimum == newsoa.minimum &&
        oldsoa.expire == newsoa.expire &&
        dns_name_equal(&oldsoa.origin, &newsoa.origin) &&
        dns_name_equal(&oldsoa.contact, &newsoa.contact))
    {
      ISC_LIST_UNLINK(del, oldtuple, link);
      dns_difftuple_free(&oldtuple);
      ISC_LIST_UNLINK(add, newtuple, link);
      dns_difftuple_free(&newtuple);
    }
  }

  /*
   * Filter out keys we manage but still allow TTL changes.
   */
  filter_keymaterial(seczone, &keydel, &keyadd, kasp != NULL, keyttl);
  filter_keymaterial(seczone, &ckeydel, &ckeyadd, kasp != NULL, ckeyttl);
  filter_keymaterial(seczone, &cdsdel, &cdsadd, kasp != NULL, cdsttl);

  /*
   * Rebuild the diff now that we have filtered it
   */
  ISC_LIST_FOREACH(del, tuple, link) {
    ISC_LIST_UNLINK(del, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(keydel, tuple, link) {
    ISC_LIST_UNLINK(keydel, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(ckeydel, tuple, link) {
    ISC_LIST_UNLINK(ckeydel, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(cdsdel, tuple, link) {
    ISC_LIST_UNLINK(cdsdel, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(add, tuple, link) {
    ISC_LIST_UNLINK(add, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(keyadd, tuple, link) {
    ISC_LIST_UNLINK(keyadd, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(ckeyadd, tuple, link) {
    ISC_LIST_UNLINK(ckeyadd, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  ISC_LIST_FOREACH(cdsadd, tuple, link) {
    ISC_LIST_UNLINK(cdsadd, tuple, link);
    dns_diff_append(diff, &tuple);
  }

  if (ISC_LIST_EMPTY(diff->tuples)) {
    return DNS_R_UNCHANGED;
  }

  /*
   * If there are still SOA records in the diff they can now be removed
   * saving the new SOA record.
   */
  if (oldtuple != NULL) {
    dns_diff_unlink(diff, oldtuple);
    dns_difftuple_free(&oldtuple);
  }

  if (newtuple != NULL) {
    dns_diff_unlink(diff, newtuple);
    *soatuple = newtuple;
  }

  return ISC_R_SUCCESS;
}

static isc_result_t
zone_get_raw_serial(dns_zone_t *raw, uint32_t *serialp) {
  isc_result_t result;

  ZONEDB_LOCK(&raw->dblock, isc_rwlocktype_read);
  if (raw->db != NULL) {
    result = dns_db_getsoaserial(raw->db, NULL, serialp);
  } else {
    result = DNS_R_NOTLOADED;
  }
  ZONEDB_UNLOCK(&raw->dblock, isc_rwlocktype_read);

  return result;
}

static zone_inline_sync_t *
inline_sync_pop(dns_zone_t *zone) {
  zone_inline_sync_t *iss = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);
  if (zone->iss != NULL) {
    /*
     * inline_sync_run() is only called from zone maintenance, so
     * zone->iss can only be parked between maintenance passes here.
     */
    iss = MOVE_OWNERSHIP(zone->iss);
  }
  UNLOCK_ZONE(zone);

  return iss;
}

static void
inline_sync_destroy(zone_inline_sync_t **issp) {
  zone_inline_sync_t *iss = NULL;

  REQUIRE(issp != NULL);

  iss = *issp;
  if (iss == NULL) {
    return;
  }
  *issp = NULL;

  INSIST(iss->mctx != NULL);

  dns_diff_clear(&iss->diff);
  dns_update_state_clear(&iss->state);
  if (iss->db != NULL) {
    if (iss->oldver != NULL) {
      dns_db_closeversion(iss->db, &iss->oldver, false);
    }
    if (iss->newver != NULL) {
      dns_db_closeversion(iss->db, &iss->newver, false);
    }
    dns_db_detach(&iss->db);
  }
  if (iss->raw != NULL) {
    dns_zone_detach(&iss->raw);
  }
  isc_mem_putanddetach(&iss->mctx, iss, sizeof(*iss));
}

static isc_result_t
inline_sync_create(dns_zone_t *zone, uint32_t *endp,
       zone_inline_sync_t **issp) {
  isc_result_t result = ISC_R_SUCCESS;
  zone_inline_sync_t *iss = NULL;
  uint32_t end = 0;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(endp != NULL);
  REQUIRE(issp != NULL && *issp == NULL);

  iss = isc_mem_cget(zone->mctx, 1, sizeof(*iss));
  isc_mem_attach(zone->mctx, &iss->mctx);

  LOCK_ZONE(zone);

  /*
   * The inline_sync_run() is loop-serialized for the zone.  Install the
   * transaction while attaching its resources so zone->iss stays the
   * single marker for sync-in-flight.
   */
  INSIST(zone->iss == NULL);
  zone->iss = iss;
  dns_diff_init(iss->mctx, &iss->diff);

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &iss->db);
  } else {
    result = ISC_R_FAILURE;
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

  if (zone->raw != NULL) {
    dns_zone_attach(zone->raw, &iss->raw);
  } else {
    result = ISC_R_FAILURE;
  }

  UNLOCK_ZONE(zone);

  CHECK(result);
  CHECK(zone_get_raw_serial(iss->raw, &end));

  LOCK_ZONE(zone);
  if (zone->sourceserialset && end == zone->sourceserial) {
    UNLOCK_ZONE(zone);
    result = DNS_R_UNCHANGED;
    goto cleanup;
  }
  iss->end = end;
  UNLOCK_ZONE(zone);

  dns_db_currentversion(iss->db, &iss->oldver);
  CHECK(dns_db_newversion(iss->db, &iss->newver));

  *endp = end;
  *issp = iss;
  return ISC_R_SUCCESS;

cleanup:
  iss = inline_sync_pop(zone);
  inline_sync_destroy(&iss);
  return result;
}

static void
zone_clear_inline_sync(dns_zone_t *zone) {
  zone_inline_sync_t *iss = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));

  iss = inline_sync_pop(zone);
  inline_sync_destroy(&iss);
}

static void
inline_secure_bootstrap(dns_zone_t *zone) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_db_t *rawdb = NULL, *newdb = NULL;
  uint32_t end = 0;

  ENTER;

  LOCK_ZONE(zone);
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) ||
      !dns__zone_inline_secure(zone))
  {
    CHECK(ISC_R_SHUTTINGDOWN);
  }

  ZONEDB_LOCK(&zone->raw->dblock, isc_rwlocktype_read);
  if (zone->raw->db != NULL) {
    dns_db_attach(zone->raw->db, &rawdb);
    result = dns_db_getsoaserial(rawdb, NULL, &end);
  } else {
    result = DNS_R_NOTLOADED;
  }
  ZONEDB_UNLOCK(&zone->raw->dblock, isc_rwlocktype_read);
  CHECK(result);

  CHECK(secure_db_create_from_raw(zone, rawdb, &newdb));

  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
  CHECK(zone_postload(zone, newdb, isc_time_now(), ISC_R_SUCCESS));

  zone->sourceserial = end;
  zone->sourceserialset = true;
  zone->inline_sync_phase = inline_sync_idle;
  zone_needdump(zone, 0);

cleanup:
  UNLOCK_ZONE(zone);

  if (newdb != NULL) {
    dns_db_detach(&newdb);
  }
  if (rawdb != NULL) {
    dns_db_detach(&rawdb);
  }
  if (result != ISC_R_SUCCESS && result != DNS_R_NOTLOADED) {
    dns_zone_log(zone, ISC_LOG_ERROR, "inline secure bootstrap: %s",
           isc_result_totext(result));
  }
}

static isc_result_t
inline_sync_finalize(dns_zone_t *zone, uint32_t newserial, uint32_t desired) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_journal_t *rjournal = NULL;
  dns_update_log_t log = { update_log_cb, NULL };
  zone_inline_sync_t *iss = NULL;
  uint32_t end = 0;

  ENTER;

  LOCK_ZONE(zone);
  iss = zone->iss;
  INSIST(iss != NULL);
  end = iss->end;
  UNLOCK_ZONE(zone);

  result = dns_update_signaturesinc(
    &log, zone, iss->db, iss->oldver, iss->newver, &iss->diff,
    zone->sigvalidityinterval, &iss->state);
  if (result == DNS_R_CONTINUE) {
    LOCK_ZONE(zone);
    zone_schedule_inline_sync(zone, inline_sync_idle);
    UNLOCK_ZONE(zone);
    return result;
  }

  /*
   * If something went wrong while trying to update the secure zone and
   * the latter was already signed before, do not apply raw zone deltas to
   * it as that would break existing DNSSEC signatures.  However, if the
   * secure zone was not yet signed (e.g. because no signing keys were
   * created for it), commence applying raw zone deltas to it so that
   * contents of the raw zone and the secure zone are kept in sync.
   */
  if (result != ISC_R_SUCCESS && dns_db_issecure(iss->db)) {
    goto cleanup;
  }

  CHECK(dns_journal_open(iss->raw->mctx, iss->raw->journal,
             DNS_JOURNAL_WRITE, &rjournal));
  CHECK(zone_journal(zone, &iss->diff, &end, "inline_sync"));

  dns_journal_set_sourceserial(rjournal, end);
  dns_journal_commit(rjournal);

  LOCK_ZONE(zone);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);

  zone->sourceserial = end;
  zone->sourceserialset = true;
  zone_needdump(zone, DNS_DUMP_DELAY);

  /*
   * Set resign time to make sure it is set to the earliest signature
   * expiration.
   */
  dns__zone_set_resigntime(zone);
  dns__zone_settimer(zone, isc_time_now());
  UNLOCK_ZONE(zone);

  dns_db_closeversion(iss->db, &iss->oldver, false);
  dns_db_closeversion(iss->db, &iss->newver, true);

  if (newserial != 0) {
    dns_zone_log(zone, ISC_LOG_INFO, "serial %u (unsigned %u)",
           newserial, desired);
  }

cleanup:
  if (rjournal != NULL) {
    dns_journal_destroy(&rjournal);
  }

  return result;
}

static void
inline_sync_run(dns_zone_t *zone) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_journal_t *rjournal = NULL;
  dns_journal_t *sjournal = NULL;
  uint32_t start = 0, end = 0;
  dns_difftuple_t *tuple = NULL, *soatuple = NULL;
  uint32_t newserial = 0, desired = 0;
  zone_inline_sync_t *iss = NULL;

  ENTER;

  CHECK(inline_sync_create(zone, &end, &iss));

  /*
   * We first attempt to sync the raw zone to the secure zone by using the
   * raw zone's journal, applying all the deltas from the latest
   * source-serial of the secure zone up to the current serial number of
   * the raw zone.
   *
   * If that fails, then we'll fall back to a direct comparison between
   * raw and secure zones.
   */
  CHECK(dns_journal_open(iss->raw->mctx, iss->raw->journal,
             DNS_JOURNAL_WRITE, &rjournal));

  result = dns_journal_open(zone->mctx, zone->journal, DNS_JOURNAL_READ,
          &sjournal);
  if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  if (!dns_journal_get_sourceserial(rjournal, &start)) {
    start = dns_journal_first_serial(rjournal);
    dns_journal_set_sourceserial(rjournal, start);
  }
  if (sjournal != NULL) {
    uint32_t serial;
    /*
     * We read the secure journal first, if that exists use its
     * value provided it is greater that from the raw journal.
     */
    if (dns_journal_get_sourceserial(sjournal, &serial) &&
        isc_serial_gt(serial, start))
    {
      start = serial;
    }
    dns_journal_destroy(&sjournal);
  }

  /*
   * Try to apply diffs from the raw zone's journal to the secure zone. If
   * that fails, we recover by syncing up the databases directly.
   */
  result = sync_secure_journal(zone, iss->raw, rjournal, start, end,
             &soatuple, &iss->diff);
  if (result == DNS_R_UNCHANGED) {
    LOCK_ZONE(zone);
    zone->sourceserial = end;
    zone->sourceserialset = true;
    UNLOCK_ZONE(zone);

    goto cleanup;
  } else if (result != ISC_R_SUCCESS) {
    result = sync_secure_db(zone, iss->raw, iss->db, iss->oldver,
          &soatuple, &iss->diff);
    if (result == DNS_R_UNCHANGED) {
      LOCK_ZONE(zone);
      zone->sourceserial = end;
      zone->sourceserialset = true;
      UNLOCK_ZONE(zone);

      goto cleanup;
    }
    CHECK(result);
  }

  CHECK(dns_diff_apply(&iss->diff, iss->db, iss->newver));

  if (soatuple != NULL) {
    uint32_t oldserial;

    CHECK(dns_db_createsoatuple(iss->db, iss->oldver,
              iss->diff.mctx, DNS_DIFFOP_DEL,
              &tuple));
    oldserial = dns_soa_getserial(&tuple->rdata);
    newserial = desired = dns_soa_getserial(&soatuple->rdata);
    if (!isc_serial_gt(newserial, oldserial)) {
      newserial = oldserial + 1;
      if (newserial == 0) {
        newserial++;
      }
      dns_soa_setserial(newserial, &soatuple->rdata);
    }
    CHECK(dns_diff_applytuple(&tuple, iss->db, iss->newver,
            &iss->diff));
    CHECK(dns_diff_applytuple(&soatuple, iss->db, iss->newver,
            &iss->diff));
  } else {
    CHECK(update_soa_serial(zone, iss->db, iss->newver, &iss->diff,
          zone->mctx, zone->updatemethod));
  }

cleanup:
  if (sjournal != NULL) {
    dns_journal_destroy(&sjournal);
  }
  if (rjournal != NULL) {
    dns_journal_destroy(&rjournal);
  }
  if (tuple != NULL) {
    dns_difftuple_free(&tuple);
  }
  if (soatuple != NULL) {
    dns_difftuple_free(&soatuple);
  }
  if (result == ISC_R_SUCCESS) {
    result = inline_sync_finalize(zone, newserial, desired);
  }
  if (result != DNS_R_CONTINUE) {
    zone_clear_inline_sync(zone);
    /*
     * In the pull model, DNS_R_UNCHANGED and DNS_R_NOTLOADED are
     * idle results.  Treating them like errors here would reset the
     * maintenance timer to "now" and either spin on an already
     * current raw serial or retry before raw loading finishes.
     */
    if (result != ISC_R_SUCCESS && result != DNS_R_UNCHANGED &&
        result != DNS_R_NOTLOADED)
    {
      dns_zone_log(zone, ISC_LOG_ERROR, "inline_sync: %s",
             isc_result_totext(result));
    }
  }
}

static void
inline_sync_resume(dns_zone_t *zone) {
  isc_result_t result = ISC_R_SUCCESS;

  ENTER;

  LOCK_ZONE(zone);
  INSIST(zone->iss != NULL);
  UNLOCK_ZONE(zone);

  result = inline_sync_finalize(zone, 0, 0);
  if (result != DNS_R_CONTINUE) {
    zone_clear_inline_sync(zone);
    if (result != ISC_R_SUCCESS && result != DNS_R_UNCHANGED &&
        result != DNS_R_NOTLOADED)
    {
      dns_zone_log(zone, ISC_LOG_ERROR, "inline_sync: %s",
             isc_result_totext(result));
    }
  }
}

STATIC_ASSERT(inline_sync_idle < inline_sync_incremental &&
          inline_sync_incremental < inline_sync_full,
        "inline sync states must be ordered by priority");

static void
zone_schedule_inline_sync(dns_zone_t *zone, inline_sync_phase_t state) {
  INSIST(LOCKED_ZONE(zone));
  INSIST(dns__zone_inline_secure(zone));
  INSIST(state == inline_sync_idle || state == inline_sync_incremental ||
         state == inline_sync_full);

  zone->inline_sync_phase = ISC_MAX(zone->inline_sync_phase, state);
  dns__zone_settimer(zone, isc_time_now());
}

static isc_result_t
checkandaddsoa(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
         dns_name_t *name, dns_rdataset_t *rdataset, uint32_t oldserial) {
  dns_rdata_soa_t soa;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_rdatalist_t temprdatalist;
  dns_rdataset_t temprdataset;
  isc_buffer_t b;
  isc_result_t result;
  unsigned char buf[DNS_SOA_BUFFERSIZE];

  result = dns_rdataset_first(rdataset);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
  dns_rdataset_current(rdataset, &rdata);
  result = dns_rdata_tostruct(&rdata, &soa);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  if (isc_serial_gt(soa.serial, oldserial)) {
    return dns_db_addrdataset(db, node, version, 0, rdataset, 0,
            NULL);
  }
  /*
   * Always bump the serial.
   */
  oldserial++;
  if (oldserial == 0) {
    oldserial++;
  }
  soa.serial = oldserial;

  /*
   * Construct a replacement rdataset.
   */
  dns_rdata_reset(&rdata);
  isc_buffer_init(&b, buf, sizeof(buf));
  result = dns_rdata_fromstruct(&rdata, rdataset->rdclass,
              dns_rdatatype_soa, &soa, &b);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
  dns_rdatalist_init(&temprdatalist);
  temprdatalist.rdclass = rdata.rdclass;
  temprdatalist.type = rdata.type;
  temprdatalist.ttl = rdataset->ttl;
  ISC_LIST_APPEND(temprdatalist.rdata, &rdata, link);

  dns_rdataset_init(&temprdataset);
  dns_rdatalist_tordataset(&temprdatalist, &temprdataset);

  dns_rdataset_getownercase(rdataset, name);
  dns_rdataset_setownercase(&temprdataset, name);
  return dns_db_addrdataset(db, node, version, 0, &temprdataset, 0, NULL);
}

/*
 * This function should populate an nsec3paramlist_t with the
 * nsecparam_t data from a zone.
 */
static isc_result_t
save_nsec3param(dns_zone_t *zone, nsec3paramlist_t *nsec3list) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset, prdataset;
  dns_dbversion_t *version = NULL;
  nsec3param_t *nsec3param = NULL;
  dns_db_t *db = NULL;
  unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(nsec3list != NULL);
  REQUIRE(ISC_LIST_EMPTY(*nsec3list));

  dns_rdataset_init(&rdataset);
  dns_rdataset_init(&prdataset);

  dns_db_attach(zone->db, &db);
  CHECK(dns_db_getoriginnode(db, &node));

  dns_db_currentversion(db, &version);
  result = dns_db_findrdataset(db, node, version,
             dns_rdatatype_nsec3param,
             dns_rdatatype_none, 0, &rdataset, NULL);

  if (result != ISC_R_SUCCESS) {
    goto getprivate;
  }

  /*
   * Walk nsec3param rdataset making a list of parameters (note that
   * multiple simultaneous nsec3 chains are annoyingly legal -- this
   * is why we use an nsec3list, even though we will usually only
   * have one).
   */
  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_t private = DNS_RDATA_INIT;

    dns_rdataset_current(&rdataset, &rdata);
    isc_log_write(DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
            ISC_LOG_DEBUG(3),
            "looping through nsec3param data");
    nsec3param = isc_mem_get(zone->mctx, sizeof(nsec3param_t));
    ISC_LINK_INIT(nsec3param, link);

    /*
     * now transfer the data from the rdata to
     * the nsec3param
     */
    dns_nsec3param_toprivate(&rdata, &private, zone->privatetype,
           nsec3param->data,
           sizeof(nsec3param->data));
    nsec3param->length = private.length;
    ISC_LIST_APPEND(*nsec3list, nsec3param, link);
  }

getprivate:
  result = dns_db_findrdataset(db, node, version, zone->privatetype,
             dns_rdatatype_none, 0, &prdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

  /*
   * walk private type records, converting them to nsec3 parameters
   * using dns_nsec3param_fromprivate(), do the right thing based on
   * CREATE and REMOVE flags
   */
  DNS_RDATASET_FOREACH(&prdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_t private = DNS_RDATA_INIT;

    dns_rdataset_current(&prdataset, &private);
    isc_log_write(DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
            ISC_LOG_DEBUG(3),
            "looping through nsec3param private data");

    /*
     * Do we have a valid private record?
     */
    if (!dns_nsec3param_fromprivate(&private, &rdata, buf,
            sizeof(buf)))
    {
      continue;
    }

    /*
     * Remove any NSEC3PARAM records scheduled to be removed.
     */
    if (NSEC3REMOVE(rdata.data[1])) {
      /*
       * Zero out the flags.
       */
      rdata.data[1] = 0;

      ISC_LIST_FOREACH(*nsec3list, nsec3p, link) {
        if (nsec3p->length ==
              (unsigned int)rdata.length + 1 &&
            memcmp(rdata.data, nsec3p->data + 1,
             nsec3p->length - 1) == 0)
        {
          ISC_LIST_UNLINK(*nsec3list, nsec3p,
              link);
          isc_mem_put(zone->mctx, nsec3p,
                sizeof(nsec3param_t));
        }
      }
      continue;
    }

    nsec3param = isc_mem_get(zone->mctx, sizeof(nsec3param_t));
    ISC_LINK_INIT(nsec3param, link);

    /*
     * Copy the remaining private records so the nsec/nsec3
     * chain gets created.
     */
    INSIST(private.length <= sizeof(nsec3param->data));
    memmove(nsec3param->data, private.data, private.length);
    nsec3param->length = private.length;
    ISC_LIST_APPEND(*nsec3list, nsec3param, link);
  }

done:
  if (result == ISC_R_NOTFOUND) {
    result = ISC_R_SUCCESS;
  }

cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }
  dns_rdataset_cleanup(&rdataset);
  dns_rdataset_cleanup(&prdataset);
  return result;
}

/*
 * Populate new zone db with private type records found by save_nsec3param().
 */
static isc_result_t
restore_nsec3param(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version,
       nsec3paramlist_t *nsec3list) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_diff_t diff;
  dns_rdata_t rdata;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(!ISC_LIST_EMPTY(*nsec3list));

  dns_diff_init(zone->mctx, &diff);

  /*
   * Loop through the list of private-type records, set the INITIAL
   * and CREATE flags, and the add the record to the apex of the tree
   * in db.
   */
  ISC_LIST_FOREACH(*nsec3list, nsec3p, link) {
    dns_rdata_init(&rdata);
    nsec3p->data[2] = DNS_NSEC3FLAG_CREATE | DNS_NSEC3FLAG_INITIAL;
    rdata.length = nsec3p->length;
    rdata.data = nsec3p->data;
    rdata.type = zone->privatetype;
    rdata.rdclass = zone->rdclass;
    result = update_one_rr(db, version, &diff, DNS_DIFFOP_ADD,
               &zone->origin, 0, &rdata);
    if (result != ISC_R_SUCCESS) {
      break;
    }
  }

  dns_diff_clear(&diff);
  return result;
}

static isc_result_t
copy_non_dnssec_records(dns_db_t *db, dns_dbversion_t *version, dns_db_t *rawdb,
      dns_dbiterator_t *dbiterator, unsigned int *oldserial) {
  dns_dbnode_t *rawnode = NULL, *node = NULL;
  dns_fixedname_t fixed;
  dns_name_t *name = dns_fixedname_initname(&fixed);
  dns_rdatasetiter_t *rdsit = NULL;
  isc_result_t result;

  result = dns_dbiterator_current(dbiterator, &rawnode, name);
  if (result != ISC_R_SUCCESS) {
    return ISC_R_SUCCESS;
  }

  dns_dbiterator_pause(dbiterator);

  CHECK(dns_db_findnode(db, name, true, &node));

  CHECK(dns_db_allrdatasets(rawdb, rawnode, NULL, 0, 0, &rdsit));

  DNS_RDATASETITER_FOREACH(rdsit) {
    dns_rdataset_t rdataset = DNS_RDATASET_INIT;
    dns_rdatasetiter_current(rdsit, &rdataset);
    if (rdataset.type == dns_rdatatype_nsec ||
        rdataset.type == dns_rdatatype_rrsig ||
        rdataset.type == dns_rdatatype_nsec3 ||
        rdataset.type == dns_rdatatype_nsec3param)
    {
      dns_rdataset_disassociate(&rdataset);
      continue;
    }
    /*
     * Allow DNSKEY, CDNSKEY, CDS because users should be able to
     * update the zone with these records from a different provider,
     * and thus they may exist in the raw version of the zone.
     */

    if (rdataset.type == dns_rdatatype_soa && oldserial != NULL) {
      result = checkandaddsoa(db, node, version, name,
            &rdataset, *oldserial);
    } else {
      result = dns_db_addrdataset(db, node, version, 0,
                &rdataset, 0, NULL);
    }
    dns_rdataset_disassociate(&rdataset);
    if (result != ISC_R_SUCCESS) {
      break;
    }
  }

cleanup:
  if (rdsit != NULL) {
    dns_rdatasetiter_destroy(&rdsit);
  }
  if (rawnode) {
    dns_db_detachnode(&rawnode);
  }
  if (node) {
    dns_db_detachnode(&node);
  }
  return result;
}

static isc_result_t
secure_db_create_from_raw(dns_zone_t *zone, dns_db_t *rawdb, dns_db_t **dbp) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_db_t *db = NULL;
  dns_dbiterator_t *dbiterator = NULL;
  dns_dbversion_t *version = NULL;
  unsigned int oldserial = 0, *oldserialp = NULL;
  nsec3paramlist_t nsec3list;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  REQUIRE(dbp != NULL && *dbp == NULL);

  ISC_LIST_INIT(nsec3list);
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    result = dns_db_getsoaserial(zone->db, NULL, &oldserial);
    if (result == ISC_R_SUCCESS) {
      oldserialp = &oldserial;
    }

    /*
     * assemble nsec3parameters from the old zone, and set a flag
     * if any are found
     */
    result = save_nsec3param(zone, &nsec3list);
    if (result != ISC_R_SUCCESS) {
      ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
      goto cleanup;
    }
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

  CHECK(dns_db_create(zone->mctx, zone->db_argv[0], &zone->origin,
          dns_dbtype_zone, zone->rdclass, zone->db_argc - 1,
          zone->db_argv + 1, &db));

  result = dns_db_setgluecachestats(db, zone->gluecachestats);
  if (result != ISC_R_NOTIMPLEMENTED) {
    CHECK(result);
  }

  CHECK(dns_db_newversion(db, &version));
  CHECK(dns_db_createiterator(rawdb, DNS_DB_NONSEC3, &dbiterator));

  DNS_DBITERATOR_FOREACH(dbiterator) {
    CHECK(copy_non_dnssec_records(db, version, rawdb, dbiterator,
                oldserialp));
  }
  dns_dbiterator_destroy(&dbiterator);

  /*
   * Call restore_nsec3param() to create private-type records from
   * the old nsec3 parameters and insert them into db
   */
  if (!ISC_LIST_EMPTY(nsec3list)) {
    CHECK(restore_nsec3param(zone, db, version, &nsec3list));
  }

  dns_db_closeversion(db, &version, true);
  *dbp = MOVE_OWNERSHIP(db);

cleanup:
  if (dbiterator != NULL) {
    dns_dbiterator_destroy(&dbiterator);
  }
  while (!ISC_LIST_EMPTY(nsec3list)) {
    nsec3param_t *nsec3p;
    nsec3p = ISC_LIST_HEAD(nsec3list);
    ISC_LIST_UNLINK(nsec3list, nsec3p, link);
    isc_mem_put(zone->mctx, nsec3p, sizeof(nsec3param_t));
  }
  if (db != NULL) {
    if (version != NULL) {
      dns_db_closeversion(db, &version, false);
    }
    dns_db_detach(&db);
  }

  INSIST(version == NULL);
  return result;
}

isc_result_t
dns_zone_replacedb(dns_zone_t *zone, dns_db_t *db, bool dump) {
  isc_result_t result;
  dns_zone_t *secure = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));
again:
  LOCK_ZONE(zone);
  if (dns__zone_inline_raw(zone)) {
    secure = zone->secure;
    INSIST(secure != zone);
    TRYLOCK_ZONE(result, secure);
    if (result != ISC_R_SUCCESS) {
      UNLOCK_ZONE(zone);
      secure = NULL;
      isc_thread_yield();
      goto again;
    }
  }
  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
  result = zone_replacedb(zone, db, dump);
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
  if (secure != NULL) {
    UNLOCK_ZONE(secure);
  }
  UNLOCK_ZONE(zone);
  return result;
}

static isc_result_t
zone_replacedb(dns_zone_t *zone, dns_db_t *db, bool dump) {
  dns_dbversion_t *ver;
  isc_result_t result;
  unsigned int soacount = 0;
  unsigned int nscount = 0;

  /*
   * 'zone' and 'zone->db' locked by caller.
   */
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(LOCKED_ZONE(zone));
  if (dns__zone_inline_raw(zone)) {
    REQUIRE(LOCKED_ZONE(zone->secure));
  }

  result = zone_get_from_db(zone, db, &nscount, &soacount, NULL, NULL,
          NULL, NULL, NULL, NULL, NULL);
  if (result == ISC_R_SUCCESS) {
    if (soacount != 1) {
      dns_zone_log(zone, ISC_LOG_ERROR, "has %d SOA records",
             soacount);
      RETERR(DNS_R_BADZONE);
    }
    if (nscount == 0 && DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNS))
    {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "has no NS records");
      if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FATALNS)) {
        RETERR(DNS_R_BADZONE);
      }
    }
  } else {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "retrieving SOA and NS records failed: %s",
           isc_result_totext(result));
    return result;
  }

  RETERR(check_nsec3param(zone, db));

  ver = NULL;
  dns_db_currentversion(db, &ver);

  /*
   * The initial version of a secondary zone is always dumped;
   * subsequent versions may be journaled instead if this
   * is enabled in the configuration.
   */
  if (zone->db != NULL && zone->journal != NULL &&
      DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IXFRFROMDIFFS) &&
      !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER))
  {
    uint32_t serial, oldserial;

    dns_zone_log(zone, ISC_LOG_DEBUG(3), "generating diffs");

    result = dns_db_getsoaserial(db, ver, &serial);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "ixfr-from-differences: unable to get "
             "new serial");
      goto fail;
    }

    /*
     * This is checked in zone_postload() for primary zones.
     */
    result = zone_get_from_db(zone, zone->db, NULL, &soacount, NULL,
            &oldserial, NULL, NULL, NULL, NULL,
            NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    RUNTIME_CHECK(soacount > 0U);
    if ((zone->type == dns_zone_secondary ||
         (zone->type == dns_zone_redirect &&
          dns_remote_addresses(&zone->primaries) != NULL)) &&
        !isc_serial_gt(serial, oldserial))
    {
      uint32_t serialmin, serialmax;
      serialmin = (oldserial + 1) & 0xffffffffU;
      serialmax = (oldserial + 0x7fffffffU) & 0xffffffffU;
      dns_zone_log(zone, ISC_LOG_ERROR,
             "ixfr-from-differences: failed: "
             "new serial (%u) out of range [%u - %u]",
             serial, serialmin, serialmax);
      result = ISC_R_RANGE;
      goto fail;
    }

    result = dns_db_diff(zone->mctx, db, ver, zone->db, NULL,
             zone->journal);
    if (result != ISC_R_SUCCESS) {
      char strbuf[ISC_STRERRORSIZE];
      strerror_r(errno, strbuf, sizeof(strbuf));
      dns_zone_log(zone, ISC_LOG_ERROR,
             "ixfr-from-differences: failed: "
             "%s",
             strbuf);
      goto fallback;
    }
    if (dump) {
      zone_needdump(zone, DNS_DUMP_DELAY);
    } else {
      zone_journal_compact(zone, zone->db, serial);
    }
    if (zone->type == dns_zone_primary &&
        dns__zone_inline_raw(zone))
    {
      zone_schedule_inline_sync(zone->secure,
              inline_sync_incremental);
    }
  } else {
  fallback:
    if (dump && zone->masterfile != NULL) {
      /*
       * If DNS_ZONEFLG_FORCEXFER was set we don't want
       * to keep the old masterfile.
       */
      if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER) &&
          remove(zone->masterfile) < 0 && errno != ENOENT)
      {
        char strbuf[ISC_STRERRORSIZE];
        strerror_r(errno, strbuf, sizeof(strbuf));
        isc_log_write(DNS_LOGCATEGORY_GENERAL,
                DNS_LOGMODULE_ZONE,
                ISC_LOG_WARNING,
                "unable to remove masterfile "
                "'%s': '%s'",
                zone->masterfile, strbuf);
      }
      if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) == 0) {
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NODELAY);
      } else {
        zone_needdump(zone, 0);
      }
    }
    if (dump && zone->journal != NULL) {
      /*
       * The in-memory database just changed, and
       * because 'dump' is set, it didn't change by
       * being loaded from disk.  Also, we have not
       * journaled diffs for this change.
       * Therefore, the on-disk journal is missing
       * the deltas for this change.  Since it can
       * no longer be used to bring the zone
       * up-to-date, it is useless and should be
       * removed.
       */
      isc_log_write(DNS_LOGCATEGORY_GENERAL,
              DNS_LOGMODULE_ZONE, ISC_LOG_DEBUG(3),
              "removing journal file");
      if (remove(zone->journal) < 0 && errno != ENOENT) {
        char strbuf[ISC_STRERRORSIZE];
        strerror_r(errno, strbuf, sizeof(strbuf));
        isc_log_write(DNS_LOGCATEGORY_GENERAL,
                DNS_LOGMODULE_ZONE,
                ISC_LOG_WARNING,
                "unable to remove journal "
                "'%s': '%s'",
                zone->journal, strbuf);
      }
    }

    if (dns__zone_inline_raw(zone)) {
      zone_schedule_inline_sync(zone->secure,
              inline_sync_full);
    }
  }

  dns_db_closeversion(db, &ver, false);

  dns_zone_log(zone, ISC_LOG_DEBUG(3), "replacing zone database");

  if (zone->db != NULL) {
    zone_detachdb(zone);
  }
  zone_attachdb(zone, db);
  dns_db_setmaxrrperset(zone->db, zone->maxrrperset);
  dns_db_setmaxtypepername(zone->db, zone->maxtypepername);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED | DNS_ZONEFLG_NEEDNOTIFY);
  return ISC_R_SUCCESS;

fail:
  dns_db_closeversion(db, &ver, false);
  return result;
}

/* The caller must hold the dblock as a writer. */
static void
zone_attachdb(dns_zone_t *zone, dns_db_t *db) {
  REQUIRE(zone->db == NULL && db != NULL);

  dns_db_attach(db, &zone->db);
}

/* The caller must hold the dblock as a writer. */
static void
zone_detachdb(dns_zone_t *zone) {
  REQUIRE(zone->db != NULL);

  dns_zone_rpz_disable_db(zone, zone->db);
  dns_zone_catz_disable_db(zone, zone->db);
  dns_db_detach(&zone->db);
}

void
dns__zone_xfrdone(dns_zone_t *zone, uint32_t *expireopt, isc_result_t result) {
  isc_time_t now, expiretime;
  bool again = false;
  unsigned int soacount;
  unsigned int nscount;
  uint32_t serial, refresh, retry, expire, minimum, soattl, oldexpire;
  isc_result_t xfrresult = result;
  bool free_needed;
  dns_zone_t *secure = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));

  dns_zone_logc(
    zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_DEBUG(1),
    expireopt == NULL ? "zone transfer finished: %s"
          : "zone transfer finished: %s, expire=%u",
    isc_result_totext(result), expireopt != NULL ? *expireopt : 0);

  /*
   * Obtaining a lock on the zone->secure (see zone_schedule_inline_sync)
   * could result in a deadlock due to a LOR so we will spin if we
   * can't obtain both locks.
   */
again:
  LOCK_ZONE(zone);
  if (dns__zone_inline_raw(zone)) {
    secure = zone->secure;
    INSIST(secure != zone);
    TRYLOCK_ZONE(result, secure);
    if (result != ISC_R_SUCCESS) {
      UNLOCK_ZONE(zone);
      secure = NULL;
      isc_thread_yield();
      goto again;
    }
  }

  INSIST(DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH));
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR);

  now = isc_time_now();
  switch (xfrresult) {
  case ISC_R_SUCCESS:
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
    FALLTHROUGH;
  case DNS_R_UPTODATE:
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FORCEXFER |
                 DNS_ZONEFLG_FIRSTREFRESH);
    /*
     * Has the zone expired underneath us?
     */
    ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
    if (zone->db == NULL) {
      ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
      goto same_primary;
    }

    oldexpire = zone->expire;

    /*
     * Update the zone structure's data from the actual
     * SOA received.
     */
    nscount = 0;
    soacount = 0;
    INSIST(zone->db != NULL);
    result = zone_get_from_db(zone, zone->db, &nscount, &soacount,
            &soattl, &serial, &refresh, &retry,
            &expire, &minimum, NULL);
    ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
    if (result == ISC_R_SUCCESS) {
      if (soacount != 1) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_ERROR,
                "transferred zone "
                "has %d SOA records",
                soacount);
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_HAVETIMERS))
        {
          zone->refresh = DNS_ZONE_DEFAULTREFRESH;
          zone->retry = DNS_ZONE_DEFAULTRETRY;
        }
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
        zone_unload(zone);
        goto next_primary;
      }
      if (nscount == 0 &&
          DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNS))
      {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_WARNING,
                "transferred zone "
                "has no NS records");
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FATALNS))
        {
          if (DNS_ZONE_FLAG(
                zone,
                DNS_ZONEFLG_HAVETIMERS))
          {
            zone->refresh =
              DNS_ZONE_DEFAULTREFRESH;
            zone->retry =
              DNS_ZONE_DEFAULTRETRY;
          }
          DNS_ZONE_CLRFLAG(
            zone, DNS_ZONEFLG_HAVETIMERS);
          zone_unload(zone);
          goto next_primary;
        }
      }
      zone->refresh = RANGE(refresh, zone->minrefresh,
                zone->maxrefresh);
      zone->retry = RANGE(retry, zone->minretry,
              zone->maxretry);
      zone->expire = RANGE(expire,
               zone->refresh + zone->retry,
               DNS_MAX_EXPIRE);
      zone->soattl = soattl;
      zone->minimum = minimum;
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
    }

    /*
     * Set our next refresh time.
     */
    if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDREFRESH)) {
      DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
      zone->refreshtime = now;
    } else {
      DNS_ZONE_JITTER_ADD(&now, zone->refresh,
              &zone->refreshtime);
    }

    /*
     * Set our next expire time. If the parent returned
     * an EXPIRE option use that to update zone->expiretime.
     */
    expire = zone->expire;
    if (expireopt != NULL && *expireopt < expire) {
      expire = *expireopt;
    }
    DNS_ZONE_TIME_ADD(&now, expire, &expiretime);
    if (oldexpire != zone->expire ||
        isc_time_compare(&expiretime, &zone->expiretime) > 0)
    {
      zone->expiretime = expiretime;
      DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_EXPIRED);
    }

    /*
     * Set loadtime.
     */
    zone->loadtime = now;

    if (result == ISC_R_SUCCESS && xfrresult == ISC_R_SUCCESS) {
      char buf[DNS_NAME_FORMATSIZE + sizeof(": TSIG ''")];
      if (zone->tsigkey != NULL) {
        char namebuf[DNS_NAME_FORMATSIZE];
        dns_name_format(zone->tsigkey->name, namebuf,
            sizeof(namebuf));
        snprintf(buf, sizeof(buf), ": TSIG '%s'",
           namebuf);
      } else {
        buf[0] = '\0';
      }
      dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
              ISC_LOG_INFO, "transferred serial %u%s",
              serial, buf);
      if (dns__zone_inline_raw(zone)) {
        zone_schedule_inline_sync(
          secure, inline_sync_incremental);
      }
    }

    /*
     * This is not necessary if we just performed a AXFR
     * however it is necessary for an IXFR / UPTODATE and
     * won't hurt with an AXFR.
     */
    if (zone->masterfile != NULL || zone->journal != NULL) {
      unsigned int delay = DNS_DUMP_DELAY;
      isc_interval_t i;
      isc_time_t when;

      /*
       * Compute effective modification time.
       */
      isc_interval_set(&i, zone->expire, 0);
      result = isc_time_subtract(&zone->expiretime, &i,
               &when);
      if (result != ISC_R_SUCCESS) {
        when = now;
      }

      result = ISC_R_FAILURE;
      if (zone->journal != NULL) {
        result = isc_file_settime(zone->journal, &when);
      }
      if (result != ISC_R_SUCCESS && zone->masterfile != NULL)
      {
        result = isc_file_settime(zone->masterfile,
                &when);
      }

      if ((DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NODELAY) != 0) ||
          result == ISC_R_FILENOTFOUND)
      {
        delay = 0;
      }

      if ((result == ISC_R_SUCCESS ||
           result == ISC_R_FILENOTFOUND) &&
          zone->masterfile != NULL)
      {
        zone_needdump(zone, delay);
      } else if (result != ISC_R_SUCCESS) {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_ERROR,
                "transfer: could not set file "
                "modification time of '%s': %s",
                zone->masterfile,
                isc_result_totext(result));
      }
    }
    DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NODELAY);
    dns__zone_stats_increment(zone,
            dns_zonestatscounter_xfrsuccess);
    break;

  case DNS_R_BADIXFR:
    /* Force retry with AXFR. */
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOIXFR);
    goto same_primary;

  case ISC_R_SHUTTINGDOWN:
    dns_remote_reset(&zone->primaries, true);
    break;

  default:
  next_primary:
    /*
     * Skip to next failed / untried primary.
     */
    dns_remote_next(&zone->primaries, true);
  same_primary:
    if (dns_remote_done(&zone->primaries)) {
      dns_remote_reset(&zone->primaries, false);
    } else {
      DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESH);
      again = true;
    }
    dns__zone_stats_increment(zone, dns_zonestatscounter_xfrfail);
    break;
  }
  dns__zone_settimer(zone, now);

  /*
   * We are called as the done callback of a zone
   * transfer object that just entered its shutting-down state or
   * failed to start.  Since we are no longer responsible for shutting
   * it down, we can detach our reference.
   */
  if (zone->xfr != NULL) {
    dns_xfrin_detach(&zone->xfr);
  }

  if (zone->tsigkey != NULL) {
    dns_tsigkey_detach(&zone->tsigkey);
  }

  if (zone->transport != NULL) {
    dns_transport_detach(&zone->transport);
  }

  /*
   * Handle any deferred journal compaction.
   */
  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDCOMPACT)) {
    dns_db_t *db = NULL;
    if (dns_zone_getdb(zone, &db) == ISC_R_SUCCESS) {
      zone_journal_compact(zone, db, zone->compact_serial);
      dns_db_detach(&db);
      DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDCOMPACT);
    }
  }

  if (secure != NULL) {
    UNLOCK_ZONE(secure);
  }
  /*
   * This transfer finishing freed up a transfer quota slot.
   * Let any other zones waiting for quota have it.
   */
  if (zone->loop != NULL &&
      zone->statelist == &dns_g_zonemgr->xfrin_in_progress)
  {
    UNLOCK_ZONE(zone);
    RWLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_write);
    ISC_LIST_UNLINK(dns_g_zonemgr->xfrin_in_progress, zone,
        statelink);
    zone->statelist = NULL;
    dns__zonemgr_resume_xfrs(dns_g_zonemgr, false);
    RWUNLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_write);
    LOCK_ZONE(zone);
  }

  /*
   * Retry with a different server if necessary.
   */
  if (again && !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    queue_soa_query(zone);
  }

  isc_refcount_decrement(&zone->irefs);
  free_needed = dns__zone_free_check(zone);
  UNLOCK_ZONE(zone);
  if (free_needed) {
    dns__zone_free(zone);
  }
}

static void
zone_loaddone(void *arg, isc_result_t result) {
  dns_load_t *load = arg;
  dns_zone_t *zone;
  isc_result_t postload_result, tresult;
  dns_zone_t *secure = NULL;

  zone = load->zone;

  ENTER;

  /*
   * If zone loading failed, remove the update db callbacks prior
   * to calling the list of callbacks in the zone load structure.
   */
  if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) {
    dns_zone_rpz_disable_db(zone, load->db);
    dns_zone_catz_disable_db(zone, load->db);
  }

  tresult = dns_db_endload(load->db, &load->callbacks);
  if (tresult != ISC_R_SUCCESS &&
      (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE))
  {
    result = tresult;
  }

  /*
   * Lock hierarchy: zmgr, zone, secure.
   */
again:
  LOCK_ZONE(zone);
  INSIST(zone != zone->raw);
  if (dns__zone_inline_raw(zone)) {
    secure = zone->secure;
    TRYLOCK_ZONE(tresult, secure);
    if (tresult != ISC_R_SUCCESS) {
      UNLOCK_ZONE(zone);
      secure = NULL;
      isc_thread_yield();
      goto again;
    }
  }
  postload_result = zone_postload(zone, load->db, load->loadtime, result);
  if (postload_result == ISC_R_SUCCESS && dns__zone_inline_secure(zone)) {
    zone_schedule_inline_sync(zone, inline_sync_incremental);
  }
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_LOADING);
  zone_idetach(&load->callbacks.zone);
  /*
   * Leave the zone frozen if the reload fails.
   */
  if ((result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE) &&
      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_THAW))
  {
    zone->update_disabled = false;
  }
  DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_THAW);
  if (secure != NULL) {
    UNLOCK_ZONE(secure);
  }
  UNLOCK_ZONE(zone);

  dns_db_detach(&load->db);
  if (zone->loadctx != NULL) {
    dns_loadctx_detach(&zone->loadctx);
  }
  isc_mem_put(zone->mctx, load, sizeof(*load));

  dns_zone_idetach(&zone);
}

static void
queue_xfrin(dns_zone_t *zone) {
  isc_result_t result;
  dns_zonemgr_t *zmgr = dns_g_zonemgr;

  ENTER;

  INSIST(zone->statelist == NULL);

  RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
  ISC_LIST_APPEND(zmgr->waiting_for_xfrin, zone, statelink);
  isc_refcount_increment0(&zone->irefs);
  zone->statelist = &zmgr->waiting_for_xfrin;
  result = dns__zonemgr_start_xfrin_ifquota(zmgr, zone);
  RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);

  if (result == ISC_R_QUOTA) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
            "zone transfer deferred due to quota");
  } else if (result != ISC_R_SUCCESS) {
    dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_ERROR,
            "starting zone transfer: %s",
            isc_result_totext(result));
  }
}

/*
 * Update forwarding support.
 */

static void
forward_destroy(dns_forward_t *forward) {
  forward->magic = 0;
  if (forward->request != NULL) {
    dns_request_destroy(&forward->request);
  }
  if (forward->msgbuf != NULL) {
    isc_buffer_free(&forward->msgbuf);
  }
  if (forward->transport != NULL) {
    dns_transport_detach(&forward->transport);
  }
  if (forward->zone != NULL) {
    LOCK(&forward->zone->lock);
    if (ISC_LINK_LINKED(forward, link)) {
      ISC_LIST_UNLINK(forward->zone->forwards, forward, link);
    }
    UNLOCK(&forward->zone->lock);
    dns_zone_idetach(&forward->zone);
  }
  isc_mem_putanddetach(&forward->mctx, forward, sizeof(*forward));
}

static isc_result_t
sendtoprimary(dns_forward_t *forward) {
  isc_result_t result;
  isc_sockaddr_t src, any;
  dns_zone_t *zone = forward->zone;
  bool tls_transport_invalid = false;
  isc_tlsctx_cache_t *zmgr_tlsctx_cache = NULL;

  LOCK_ZONE(zone);

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    UNLOCK_ZONE(zone);
    return ISC_R_CANCELED;
  }

next:
  if (forward->which >= dns_remote_count(&forward->zone->primaries)) {
    UNLOCK_ZONE(zone);
    return ISC_R_NOMORE;
  }

  forward->addr = dns_remote_addr(&zone->primaries, forward->which);

  if (isc_sockaddr_disabled(&forward->addr)) {
    forward->which++;
    goto next;
  }

  /*
   * Always use TCP regardless of whether the original update used TCP.
   */
  switch (isc_sockaddr_pf(&forward->addr)) {
  case PF_INET:
    isc_sockaddr_any(&any);
    src = zone->primaries.sources[forward->which];
    if (isc_sockaddr_equal(&src, &any)) {
      src = zone_addr4_tosockaddr(&zone->xfrsource4);
    }
    break;
  case PF_INET6:
    isc_sockaddr_any6(&any);
    src = zone->primaries.sources[forward->which];
    if (isc_sockaddr_equal(&src, &any)) {
      src = zone_addr6_tosockaddr(&zone->xfrsource6);
    }
    break;
  default:
    result = ISC_R_NOTIMPLEMENTED;
    goto unlock;
  }

  if (forward->transport != NULL) {
    dns_transport_detach(&forward->transport);
  }

  if (dns_remote_tlsname(&zone->primaries) != NULL &&
      zone->primaries.tlsnames[forward->which] != NULL)
  {
    dns_view_t *view = dns_zone_getview(zone);
    dns_name_t *tlsname = zone->primaries.tlsnames[forward->which];

    result = dns_view_gettransport(view, DNS_TRANSPORT_TLS, tlsname,
                 &forward->transport);

    if (result != ISC_R_SUCCESS) {
      /* Log the error message when unlocked. */
      tls_transport_invalid = true;
      goto unlock;
    }
  }

  dns__zonemgr_tlsctx_attach(dns_g_zonemgr, &zmgr_tlsctx_cache);
  const unsigned int connect_timeout = isc_nm_getprimariestimeout() /
               MS_PER_SEC;
  result = dns_request_createraw(
    forward->zone->view->requestmgr, forward->msgbuf, &src,
    &forward->addr, forward->transport, zmgr_tlsctx_cache,
    forward->options, connect_timeout, TCP_REQUEST_TIMEOUT, 0, 0,
    forward->zone->loop, forward_callback, forward,
    &forward->request);

  isc_tlsctx_cache_detach(&zmgr_tlsctx_cache);

  if (result == ISC_R_SUCCESS) {
    if (!ISC_LINK_LINKED(forward, link)) {
      ISC_LIST_APPEND(zone->forwards, forward, link);
    }
  }

unlock:
  UNLOCK_ZONE(zone);

  if (tls_transport_invalid) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "could not get TLS configuration "
           "for dynamic update: %s",
           isc_result_totext(result));
  }

  return result;
}

static void
forward_callback(void *arg) {
  dns_request_t *request = (dns_request_t *)arg;
  dns_forward_t *forward = dns_request_getarg(request);
  dns_message_t *msg = NULL;
  char primary[ISC_SOCKADDR_FORMATSIZE];
  isc_result_t result;
  dns_zone_t *zone;

  INSIST(DNS_FORWARD_VALID(forward));
  zone = forward->zone;
  INSIST(DNS_ZONE_VALID(zone));

  ENTER;

  isc_sockaddr_format(&forward->addr, primary, sizeof(primary));

  result = dns_request_getresult(request);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_INFO,
           "could not forward dynamic update to %s: %s",
           primary, isc_result_totext(result));
    goto next_primary;
  }

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE,
         &msg);

  result = dns_request_getresponse(request, msg,
           DNS_MESSAGEPARSE_PRESERVEORDER |
             DNS_MESSAGEPARSE_CLONEBUFFER);
  if (result != ISC_R_SUCCESS) {
    goto next_primary;
  }

  /*
   * Unexpected opcode.
   */
  if (msg->opcode != dns_opcode_update) {
    char opcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, opcode, sizeof(opcode));
    (void)dns_opcode_totext(msg->opcode, &rb);

    dns_zone_log(zone, ISC_LOG_INFO,
           "forwarding dynamic update: "
           "unexpected opcode (%.*s) from %s",
           (int)rb.used, opcode, primary);
    goto next_primary;
  }

  switch (msg->rcode) {
  /*
   * Pass these rcodes back to client.
   */
  case dns_rcode_noerror:
  case dns_rcode_yxdomain:
  case dns_rcode_yxrrset:
  case dns_rcode_nxrrset:
  case dns_rcode_refused:
  case dns_rcode_nxdomain: {
    char rcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, rcode, sizeof(rcode));
    (void)dns_rcode_totext(msg->rcode, &rb);
    dns_zone_log(zone, ISC_LOG_INFO,
           "forwarded dynamic update: "
           "primary %s returned: %.*s",
           primary, (int)rb.used, rcode);
    break;
  }

  /* These should not occur if the primaries/zone are valid. */
  case dns_rcode_notzone:
  case dns_rcode_notauth: {
    char rcode[128];
    isc_buffer_t rb;

    isc_buffer_init(&rb, rcode, sizeof(rcode));
    (void)dns_rcode_totext(msg->rcode, &rb);
    dns_zone_log(zone, ISC_LOG_WARNING,
           "forwarding dynamic update: "
           "unexpected response: primary %s returned: %.*s",
           primary, (int)rb.used, rcode);
    goto next_primary;
  }

  /* Try another server for these rcodes. */
  case dns_rcode_formerr:
  case dns_rcode_servfail:
  case dns_rcode_notimp:
  case dns_rcode_badvers:
  default:
    goto next_primary;
  }

  /* call callback */
  (forward->callback)(forward->callback_arg, ISC_R_SUCCESS, msg);
  msg = NULL;
  dns_request_destroy(&forward->request);
  forward_destroy(forward);
  return;

next_primary:
  if (msg != NULL) {
    dns_message_detach(&msg);
  }
  forward->which++;
  dns_request_destroy(&forward->request);
  result = sendtoprimary(forward);
  if (result != ISC_R_SUCCESS) {
    /* call callback */
    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "exhausted dynamic update forwarder list");
    (forward->callback)(forward->callback_arg, result, NULL);
    forward_destroy(forward);
  }
}

isc_result_t
dns_zone_forwardupdate(dns_zone_t *zone, dns_message_t *msg,
           dns_updatecallback_t callback, void *callback_arg) {
  dns_forward_t *forward;
  isc_result_t result;
  isc_region_t *mr;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(msg != NULL);
  REQUIRE(callback != NULL);

  forward = isc_mem_get(zone->mctx, sizeof(*forward));
  *forward = (dns_forward_t){ .callback = callback,
            .callback_arg = callback_arg,
            .options = DNS_REQUESTOPT_TCP };
  ISC_LINK_INIT(forward, link);
  forward->magic = FORWARD_MAGIC;

  /*
   * If we have a SIG(0) signed message we need to preserve the
   * query id as that is included in the SIG(0) computation.
   */
  if (msg->sig0 != NULL) {
    forward->options |= DNS_REQUESTOPT_FIXEDID;
  }

  mr = dns_message_getrawmessage(msg);
  if (mr == NULL) {
    CLEANUP(ISC_R_UNEXPECTEDEND);
  }

  isc_buffer_allocate(zone->mctx, &forward->msgbuf, mr->length);
  CHECK(isc_buffer_copyregion(forward->msgbuf, mr));

  isc_mem_attach(zone->mctx, &forward->mctx);
  dns_zone_iattach(zone, &forward->zone);
  result = sendtoprimary(forward);

cleanup:
  if (result != ISC_R_SUCCESS) {
    forward_destroy(forward);
  }
  return result;
}

static isc_mutex_t *
zone_keymgmt_getlock(dns_zone_t *zone) {
  uint32_t hash = dns_name_hash(&zone->origin);
  return &keymgmt_buckets_g[hash % ARRAY_SIZE(keymgmt_buckets_g)].lock;
}

void
dns__zone_keymgmt_initialize(void) {
  for (size_t idx = 0; idx < ARRAY_SIZE(keymgmt_buckets_g); ++idx) {
    isc_mutex_init(&keymgmt_buckets_g[idx].lock);
  }
}

void
dns__zone_keymgmt_shutdown(void) {
  for (size_t idx = 0; idx < ARRAY_SIZE(keymgmt_buckets_g); ++idx) {
    isc_mutex_destroy(&keymgmt_buckets_g[idx].lock);
  }
}

static void
zone_saveunique(dns_zone_t *zone, const char *path, const char *templat) {
  char *buf;
  int buflen;
  isc_result_t result;

  buflen = strlen(path) + strlen(templat) + 2;

  buf = isc_mem_get(zone->mctx, buflen);

  CHECK(isc_file_template(path, templat, buf, buflen));

  CHECK(isc_file_renameunique(path, buf));

  dns_zone_log(zone, ISC_LOG_WARNING,
         "unable to load from '%s'; "
         "renaming file to '%s' for failure analysis and "
         "retransferring.",
         path, buf);

cleanup:
  isc_mem_put(zone->mctx, buf, buflen);
}

void
dns_zone_stopxfr(dns_zone_t *zone) {
  dns_xfrin_t *xfr = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));

  RWLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_read);
  LOCK_ZONE(zone);
  if (zone->statelist == &dns_g_zonemgr->xfrin_in_progress &&
      zone->xfr != NULL)
  {
    dns_xfrin_attach(zone->xfr, &xfr);
  }
  UNLOCK_ZONE(zone);
  RWUNLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_read);

  if (xfr != NULL) {
    dns_xfrin_shutdown(xfr);
    dns_xfrin_detach(&xfr);
  }
}

void
dns_zone_forcexfr(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  if (zone->type == dns_zone_primary ||
      (zone->type == dns_zone_redirect &&
       dns_remote_addresses(&zone->primaries) == NULL))
  {
    return;
  }

  LOCK_ZONE(zone);
  DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FORCEXFER);
  UNLOCK_ZONE(zone);
  dns_zone_refresh(zone);
}

bool
dns_zone_isforced(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER);
}

static void
zone_namerd_tostr(dns_zone_t *zone, char *buf, size_t length) {
  isc_result_t result = ISC_R_FAILURE;
  isc_buffer_t buffer;

  REQUIRE(buf != NULL);
  REQUIRE(length > 1U);

  /*
   * Leave space for terminating '\0'.
   */
  isc_buffer_init(&buffer, buf, (unsigned int)length - 1);
  if (zone->type != dns_zone_redirect && zone->type != dns_zone_key) {
    if (dns_name_dynamic(&zone->origin)) {
      result = dns_name_totext(
        &zone->origin, DNS_NAME_OMITFINALDOT, &buffer);
    }
    if (result != ISC_R_SUCCESS &&
        isc_buffer_availablelength(&buffer) >=
          (sizeof("<UNKNOWN>") - 1))
    {
      isc_buffer_putstr(&buffer, "<UNKNOWN>");
    }

    if (isc_buffer_availablelength(&buffer) > 0) {
      isc_buffer_putstr(&buffer, "/");
    }
    (void)dns_rdataclass_totext(zone->rdclass, &buffer);
  }

  const char *viewname = dns__viewname_display(&zone->viewname);
  if (viewname != NULL &&
      strlen(viewname) < isc_buffer_availablelength(&buffer))
  {
    isc_buffer_putstr(&buffer, "/");
    isc_buffer_putstr(&buffer, viewname);
  }
  /* Logging also runs without the zone lock.  These configuration
   * fields are changed before publication or with exclusive access. */
  if (zone->raw != NULL && 9U < isc_buffer_availablelength(&buffer)) {
    isc_buffer_putstr(&buffer, " (signed)");
  }
  if (zone->secure != NULL && 11U < isc_buffer_availablelength(&buffer)) {
    isc_buffer_putstr(&buffer, " (unsigned)");
  }

  buf[isc_buffer_usedlength(&buffer)] = '\0';
}

isc_result_t
dns_zone_getxfr(dns_zone_t *zone, dns_xfrin_t **xfrp, bool *is_firstrefresh,
    bool *is_running, bool *is_deferred, bool *is_presoa,
    bool *is_pending, bool *needs_refresh) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(xfrp != NULL && *xfrp == NULL);

  if (zone->loop == NULL) {
    return ISC_R_FAILURE;
  }

  /* Reset. */
  *is_firstrefresh = false;
  *is_running = false;
  *is_deferred = false;
  *is_presoa = false;
  *is_pending = false;
  *needs_refresh = false;

  RWLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_read);
  LOCK_ZONE(zone);
  *is_firstrefresh = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FIRSTREFRESH);
  if (zone->xfr != NULL) {
    dns_xfrin_attach(zone->xfr, xfrp);
  }
  if (zone->statelist == &dns_g_zonemgr->xfrin_in_progress) {
    *is_running = true;
    /*
     * The NEEDREFRESH flag is set only when a notify was received
     * while the current zone transfer is running.
     */
    *needs_refresh = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
  } else if (zone->statelist == &dns_g_zonemgr->waiting_for_xfrin) {
    *is_deferred = true;
  } else if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH)) {
    if (zone->request != NULL) {
      *is_presoa = true;
    } else {
      *is_pending = true;
    }
  } else {
    /*
     * No operation is ongoing or pending, just check if the zone
     * needs a refresh by looking at the refresh and expire times.
     */
    if (zone->type == dns_zone_secondary ||
        zone->type == dns_zone_mirror ||
        zone->type == dns_zone_stub)
    {
      isc_time_t now = isc_time_now();
      if (isc_time_compare(&now, &zone->refreshtime) >= 0 ||
          isc_time_compare(&now, &zone->expiretime) >= 0)
      {
        *needs_refresh = true;
      }
    }
  }
  UNLOCK_ZONE(zone);
  RWUNLOCK(&dns_g_zonemgr->rwlock, isc_rwlocktype_read);

  return ISC_R_SUCCESS;
}

void
dns_zone_lock_keyfiles(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  if (zone->kasp == NULL) {
    /* No need to lock, nothing is writing key files. */
    return;
  }

  isc_mutex_lock(zone_keymgmt_getlock(zone));
}

void
dns_zone_unlock_keyfiles(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  if (zone->kasp == NULL) {
    /* No need to lock, nothing is writing key files. */
    return;
  }

  isc_mutex_unlock(zone_keymgmt_getlock(zone));
}

isc_result_t
dns_zone_checknames(dns_zone_t *zone, const dns_name_t *name,
        dns_rdata_t *rdata) {
  bool ok = true;
  bool fail = false;
  char namebuf[DNS_NAME_FORMATSIZE];
  char namebuf2[DNS_NAME_FORMATSIZE];
  char typebuf[DNS_RDATATYPE_FORMATSIZE];
  int level = ISC_LOG_WARNING;
  dns_name_t bad;

  REQUIRE(DNS_ZONE_VALID(zone));

  if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMES) &&
      rdata->type != dns_rdatatype_nsec3)
  {
    return ISC_R_SUCCESS;
  }

  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMESFAIL) ||
      rdata->type == dns_rdatatype_nsec3)
  {
    level = ISC_LOG_ERROR;
    fail = true;
  }

  ok = dns_rdata_checkowner(name, rdata->rdclass, rdata->type, true);
  if (!ok) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    dns_rdatatype_format(rdata->type, typebuf, sizeof(typebuf));
    dns_zone_log(zone, level, "%s/%s: %s", namebuf, typebuf,
           isc_result_totext(DNS_R_BADOWNERNAME));
    if (fail) {
      return DNS_R_BADOWNERNAME;
    }
  }

  dns_name_init(&bad);
  ok = dns_rdata_checknames(rdata, name, &bad);
  if (!ok) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    dns_name_format(&bad, namebuf2, sizeof(namebuf2));
    dns_rdatatype_format(rdata->type, typebuf, sizeof(typebuf));
    dns_zone_log(zone, level, "%s/%s: %s: %s ", namebuf, typebuf,
           namebuf2, isc_result_totext(DNS_R_BADNAME));
    if (fail) {
      return DNS_R_BADNAME;
    }
  }

  return ISC_R_SUCCESS;
}

/*
 * Called when a dynamic update for an NSEC3PARAM record is received.
 *
 * If set, transform the NSEC3 salt into human-readable form so that it can be
 * logged.  Then call zone_addnsec3chain(), passing NSEC3PARAM RDATA to it.
 */
isc_result_t
dns_zone_addnsec3chain(dns_zone_t *zone, dns_rdata_nsec3param_t *nsec3param) {
  isc_result_t result;
  char salt[255 * 2 + 1];

  REQUIRE(DNS_ZONE_VALID(zone));

  result = dns_nsec3param_salttotext(nsec3param, salt, sizeof(salt));
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
  dnssec_log(zone, ISC_LOG_NOTICE,
       "dns_zone_addnsec3chain(hash=%u, iterations=%u, salt=%s)",
       nsec3param->hash, nsec3param->iterations, salt);
  LOCK_ZONE(zone);
  result = zone_addnsec3chain(zone, nsec3param);
  UNLOCK_ZONE(zone);

  return result;
}

static isc_result_t
zone_signwithkey(dns_zone_t *zone, dst_algorithm_t algorithm, uint16_t keyid,
     bool deleteit, bool fullsign) {
  dns_signing_t *signing = NULL;
  isc_result_t result = ISC_R_SUCCESS;
  isc_time_t now;
  dns_db_t *db = NULL;

  signing = isc_mem_get(zone->mctx, sizeof *signing);

  signing->magic = 0;
  signing->db = NULL;
  signing->dbiterator = NULL;
  signing->algorithm = algorithm;
  signing->keyid = keyid;
  signing->deleteit = deleteit;
  signing->fullsign = fullsign;
  signing->done = false;

  now = isc_time_now();

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

  if (db == NULL) {
    CLEANUP(ISC_R_NOTFOUND);
  }

  dns_db_attach(db, &signing->db);

  ISC_LIST_FOREACH(zone->signing, current, link) {
    if (current->db == signing->db &&
        current->algorithm == signing->algorithm &&
        current->keyid == signing->keyid)
    {
      if (current->deleteit != signing->deleteit) {
        current->done = true;
      } else {
        goto cleanup;
      }
    }
  }

  result = dns_db_createiterator(signing->db, 0, &signing->dbiterator);

  if (result == ISC_R_SUCCESS) {
    result = dns_dbiterator_first(signing->dbiterator);
  }
  if (result == ISC_R_SUCCESS) {
    dns_dbiterator_pause(signing->dbiterator);
    ISC_LIST_INITANDAPPEND(zone->signing, signing, link);
    signing = NULL;
    if (isc_time_isepoch(&zone->signingtime)) {
      zone->signingtime = now;
      if (zone->loop != NULL) {
        dns__zone_settimer(zone, now);
      }
    }
  }

cleanup:
  if (signing != NULL) {
    if (signing->db != NULL) {
      dns_db_detach(&signing->db);
    }
    if (signing->dbiterator != NULL) {
      dns_dbiterator_destroy(&signing->dbiterator);
    }
    isc_mem_put(zone->mctx, signing, sizeof *signing);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }
  return result;
}

/* Called once; *timep should be set to the current time. */
static isc_result_t
next_keyevent(dst_key_t *key, isc_stdtime_t *timep) {
  isc_result_t result;
  isc_stdtime_t now, then = 0, event;
  int i;

  now = *timep;

  for (i = 0; i < DST_MAX_TIMES; i++) {
    result = dst_key_gettime(key, i, &event);
    if (result == ISC_R_SUCCESS && event > now &&
        (then == 0 || event < then))
    {
      then = event;
    }
  }

  if (then != 0) {
    *timep = then;
    return ISC_R_SUCCESS;
  }

  return ISC_R_NOTFOUND;
}

static isc_result_t
rr_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    const dns_rdata_t *rdata, bool *flag) {
  dns_rdataset_t rdataset;
  dns_dbnode_t *node = NULL;
  isc_result_t result;

  dns_rdataset_init(&rdataset);
  if (rdata->type == dns_rdatatype_nsec3) {
    CHECK(dns_db_findnsec3node(db, name, false, &node));
  } else {
    CHECK(dns_db_findnode(db, name, false, &node));
  }
  result = dns_db_findrdataset(db, node, ver, rdata->type, 0,
             (isc_stdtime_t)0, &rdataset, NULL);
  if (result == ISC_R_NOTFOUND) {
    *flag = false;
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  bool matched = false;
  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t myrdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &myrdata);
    if (dns_rdata_compare(&myrdata, rdata) == 0) {
      matched = true;
      break;
    }
  }
  dns_rdataset_disassociate(&rdataset);
  *flag = matched;

cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

/*
 * Add records to signal the state of signing or of key removal.
 */
static isc_result_t
add_signing_records(dns_db_t *db, dns_rdatatype_t privatetype,
        dns_dbversion_t *ver, dns_diff_t *diff, bool sign_all) {
  dns_difftuple_t *newtuple = NULL;
  dns_rdata_dnskey_t dnskey;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  bool flag;
  isc_region_t r;
  isc_result_t result = ISC_R_SUCCESS;
  uint16_t keyid;
  unsigned char data[SIGNING_RECORD_SIZE];
  dns_name_t *name = dns_db_origin(db);
  dns_difftuplelist_t add = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t del = ISC_LIST_INITIALIZER;
  dns_difftuplelist_t tuples = ISC_LIST_INITIALIZER;

  /*
   * Move non DNSKEY and not DNSSEC DNSKEY records to tuples
   * and sort the remaining DNSKEY records to add and del.
   */
  ISC_LIST_FOREACH(diff->tuples, tuple, link) {
    if (tuple->rdata.type != dns_rdatatype_dnskey) {
      dns_diff_unlink(diff, tuple);
      ISC_LIST_APPEND(tuples, tuple, link);
      continue;
    }

    result = dns_rdata_tostruct(&tuple->rdata, &dnskey);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    if ((dnskey.flags & DNS_KEYOWNER_ZONE) == 0) {
      dns_diff_unlink(diff, tuple);
      ISC_LIST_APPEND(tuples, tuple, link);
      continue;
    }

    dns_diff_unlink(diff, tuple);
    switch (tuple->op) {
    case DNS_DIFFOP_DEL:
    case DNS_DIFFOP_DELRESIGN:
      ISC_LIST_APPEND(del, tuple, link);
      break;
    case DNS_DIFFOP_ADD:
    case DNS_DIFFOP_ADDRESIGN:
      ISC_LIST_APPEND(add, tuple, link);
      break;
    default:
      UNREACHABLE();
    }
  }

  /*
   * Put the tuples that don't need more processing back onto
   * diff->tuples.
   */
  ISC_LIST_FOREACH(tuples, tuple, link) {
    ISC_LIST_UNLINK(tuples, tuple, link);
    dns_diff_append(diff, &tuple);
  }

  /*
   * Filter out DNSKEY TTL changes and put them back onto diff->tuples.
   */
  ISC_LIST_FOREACH(del, deltuple, link) {
    ISC_LIST_FOREACH(add, addtuple, link) {
      int n = dns_rdata_compare(&deltuple->rdata,
              &addtuple->rdata);
      if (n == 0) {
        ISC_LIST_UNLINK(del, deltuple, link);
        dns_diff_append(diff, &deltuple);
        ISC_LIST_UNLINK(add, addtuple, link);
        dns_diff_append(diff, &addtuple);
        break;
      }
    }
  }

  /*
   * Combine any remaining DNSKEY changes together.
   */
  ISC_LIST_APPENDLIST(tuples, add, link);
  ISC_LIST_APPENDLIST(tuples, del, link);

  /*
   * Add private records for keys that have been removed
   * or added.
   */
  ISC_LIST_FOREACH(tuples, tuple, link) {
    dst_algorithm_t algorithm;
    dns_rdata_toregion(&tuple->rdata, &r);

    keyid = dst_region_computeid(&r);

    algorithm = dst_algorithm_fromdata(dnskey.algorithm,
               dnskey.data, dnskey.datalen);
    data[0] = dnskey.algorithm;
    data[1] = (keyid & 0xff00) >> 8;
    data[2] = (keyid & 0xff);
    data[3] = (tuple->op == DNS_DIFFOP_ADD) ? 0 : 1;
    data[4] = 0;
    data[5] = (algorithm & 0xff00) >> 8;
    data[6] = (algorithm & 0xff);
    rdata.data = data;
    rdata.length = algorithm < 256 ? OLD_SIGNING_RECORD_SIZE
                 : sizeof(data);
    rdata.type = privatetype;
    rdata.rdclass = tuple->rdata.rdclass;

    if (sign_all || tuple->op == DNS_DIFFOP_DEL) {
      CHECK(rr_exists(db, ver, name, &rdata, &flag));
      if (flag) {
        continue;
      }

      dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD, name,
               0, &rdata, &newtuple);
      CHECK(dns_diff_applytuple(&newtuple, db, ver, diff));
      INSIST(newtuple == NULL);
    }

    /*
     * Remove any record which says this operation has already
     * completed.
     */
    data[4] = 1;
    CHECK(rr_exists(db, ver, name, &rdata, &flag));
    if (flag) {
      dns_difftuple_create(diff->mctx, DNS_DIFFOP_DEL, name,
               0, &rdata, &newtuple);
      CHECK(dns_diff_applytuple(&newtuple, db, ver, diff));
      INSIST(newtuple == NULL);
    }
  }

cleanup:
  /*
   * Put the DNSKEY changes we cared about back on diff->tuples.
   */
  ISC_LIST_FOREACH(tuples, tuple, link) {
    ISC_LIST_UNLINK(tuples, tuple, link);
    dns_diff_append(diff, &tuple);
  }
  INSIST(ISC_LIST_EMPTY(add));
  INSIST(ISC_LIST_EMPTY(del));
  INSIST(ISC_LIST_EMPTY(tuples));
  return result;
}

/*
 * See if dns__zone_updatesigs() will update signature for RRset 'rrtype' at
 * the apex, and if not tickle them and cause to sign so that newly activated
 * keys are used.
 */
static isc_result_t
tickle_apex_rrset(dns_rdatatype_t rrtype, dns_zone_t *zone, dns_db_t *db,
      dns_dbversion_t *ver, isc_stdtime_t now, dns_diff_t *diff,
      dns__zonediff_t *zonediff, dst_key_t **keys,
      unsigned int nkeys, isc_stdtime_t inception,
      isc_stdtime_t keyexpire) {
  isc_result_t result;
  bool apexsig = false;

  ISC_LIST_FOREACH(diff->tuples, tuple, link) {
    if (tuple->rdata.type == rrtype &&
        dns_name_equal(&tuple->name, &zone->origin))
    {
      apexsig = true;
      break;
    }
  }

  if (!apexsig) {
    result = del_sigs(zone, db, ver, &zone->origin, rrtype,
          zonediff, keys, nkeys, now, false);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "sign_apex:del_sigs -> %s",
           isc_result_totext(result));
      return result;
    }
    result = add_sigs(db, ver, &zone->origin, zone, rrtype,
          zonediff->diff, keys, nkeys, zone->mctx, now,
          inception, keyexpire);
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "sign_apex:add_sigs -> %s",
           isc_result_totext(result));
      return result;
    }
  }

  return ISC_R_SUCCESS;
}

static isc_result_t
sign_apex(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
    isc_stdtime_t now, dns_diff_t *diff, dns__zonediff_t *zonediff) {
  isc_result_t result;
  isc_stdtime_t inception, soaexpire, keyexpire;
  dst_key_t *zone_keys[DNS_MAXZONEKEYS];
  unsigned int nkeys = 0, i;

  result = dns_zone_findkeys(zone, db, ver, now, zone->mctx,
           DNS_MAXZONEKEYS, zone_keys, &nkeys);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "sign_apex:dns_zone_findkeys -> %s",
         isc_result_totext(result));
    return result;
  }

  inception = now - 3600; /* Allow for clock skew. */
  soaexpire = now + dns_zone_getsigvalidityinterval(zone);

  keyexpire = dns_zone_getkeyvalidityinterval(zone);
  if (keyexpire == 0) {
    keyexpire = soaexpire - 1;
  } else {
    keyexpire += now;
  }

  /*
   * See if dns__zone_updatesigs() will update DNSKEY/CDS/CDNSKEY
   * signature and if not cause them to sign so that newly activated
   * keys are used.
   */
  CHECK(tickle_apex_rrset(dns_rdatatype_dnskey, zone, db, ver, now, diff,
        zonediff, zone_keys, nkeys, inception,
        keyexpire));
  CHECK(tickle_apex_rrset(dns_rdatatype_cds, zone, db, ver, now, diff,
        zonediff, zone_keys, nkeys, inception,
        keyexpire));
  CHECK(tickle_apex_rrset(dns_rdatatype_cdnskey, zone, db, ver, now, diff,
        zonediff, zone_keys, nkeys, inception,
        keyexpire));

  result = dns__zone_updatesigs(diff, db, ver, zone_keys, nkeys, zone,
              inception, soaexpire, keyexpire, now,
              zonediff);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "sign_apex:dns__zone_updatesigs -> %s",
         isc_result_totext(result));
  }

cleanup:
  for (i = 0; i < nkeys; i++) {
    dst_key_free(&zone_keys[i]);
  }
  return result;
}

static isc_result_t
clean_nsec3param(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
     dns_diff_t *diff) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset;

  dns_rdataset_init(&rdataset);
  CHECK(dns_db_getoriginnode(db, &node));

  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey,
             dns_rdatatype_none, 0, &rdataset, NULL);
  dns_rdataset_cleanup(&rdataset);
  if (result != ISC_R_NOTFOUND) {
    goto cleanup;
  }

  result = dns_nsec3param_deletechains(db, ver, zone, true, diff);

cleanup:
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  return result;
}

/*
 * Given an RRSIG rdataset and an algorithm, determine whether there
 * are any signatures using that algorithm.
 */
static bool
signed_with_alg(dns_rdataset_t *rdataset, dst_algorithm_t alg) {
  dst_algorithm_t sigalg;

  REQUIRE(rdataset == NULL || rdataset->type == dns_rdatatype_rrsig);
  if (rdataset == NULL || !dns_rdataset_isassociated(rdataset)) {
    return false;
  }

  DNS_RDATASET_FOREACH(rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_rrsig_t rrsig;

    dns_rdataset_current(rdataset, &rdata);
    dns_rdata_tostruct(&rdata, &rrsig);
    sigalg = dst_algorithm_fromdata(rrsig.algorithm,
            rrsig.signature, rrsig.siglen);
    if (sigalg == alg) {
      return true;
    }
  }

  return false;
}

static isc_result_t
add_chains(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
     dns_diff_t *diff) {
  dns_name_t *origin;
  bool build_nsec3;
  isc_result_t result;

  origin = dns_db_origin(db);
  CHECK(dns_private_chains(db, ver, zone->privatetype, NULL,
         &build_nsec3));
  if (build_nsec3) {
    CHECK(dns_nsec3_addnsec3sx(db, ver, origin, zone_nsecttl(zone),
             false, zone->privatetype, diff));
  }
  CHECK(updatesecure(db, ver, origin, zone_nsecttl(zone), true, diff));

cleanup:
  return result;
}

static void
dnssec_report(const char *format, ...) {
  va_list args;
  va_start(args, format);
  isc_log_vwrite(DNS_LOGCATEGORY_DNSSEC, DNS_LOGMODULE_ZONE, ISC_LOG_INFO,
           format, args);
  va_end(args);
}

static void
checkds_destroy(dns_checkds_t *checkds, bool locked) {
  REQUIRE(DNS_CHECKDS_VALID(checkds));

  dns_zone_log(checkds->zone, ISC_LOG_DEBUG(3),
         "checkds: destroy DS query");

  if (checkds->zone != NULL) {
    if (!locked) {
      LOCK_ZONE(checkds->zone);
    }
    REQUIRE(LOCKED_ZONE(checkds->zone));
    if (ISC_LINK_LINKED(checkds, link)) {
      ISC_LIST_UNLINK(checkds->zone->checkds_requests,
          checkds, link);
    }
    if (!locked) {
      UNLOCK_ZONE(checkds->zone);
    }
    if (locked) {
      zone_idetach(&checkds->zone);
    } else {
      dns_zone_idetach(&checkds->zone);
    }
  }
  if (checkds->find != NULL) {
    dns_adb_destroyfind(&checkds->find);
  }
  if (checkds->request != NULL) {
    dns_request_destroy(&checkds->request);
  }
  if (dns_name_dynamic(&checkds->ns)) {
    dns_name_free(&checkds->ns, checkds->mctx);
  }
  if (checkds->key != NULL) {
    dns_tsigkey_detach(&checkds->key);
  }
  if (checkds->transport != NULL) {
    dns_transport_detach(&checkds->transport);
  }
  INSIST(checkds->rlevent == NULL);
  isc_mem_putanddetach(&checkds->mctx, checkds, sizeof(*checkds));
}

static isc_result_t
make_dnskey(dst_key_t *key, unsigned char *buf, int bufsize,
      dns_rdata_t *target) {
  isc_buffer_t b;
  isc_region_t r;

  isc_buffer_init(&b, buf, bufsize);
  RETERR(dst_key_todns(key, &b));

  dns_rdata_reset(target);
  isc_buffer_usedregion(&b, &r);
  dns_rdata_fromregion(target, dst_key_class(key), dns_rdatatype_dnskey,
           &r);
  return ISC_R_SUCCESS;
}

static bool
do_checkds(dns_zone_t *zone, dst_key_t *key, isc_stdtime_t now,
     bool dspublish) {
  dns_kasp_t *kasp = zone->kasp;
  isc_result_t result;
  uint32_t count = 0;
  uint32_t num;

  switch (zone->checkdstype) {
  case dns_checkdstype_yes:
    num = zone->parent_nscount;
    break;
  case dns_checkdstype_explicit:
    num = dns_remote_count(&zone->parentals);
    break;
  case dns_checkdstype_no:
  default:
    dns_zone_log(zone, ISC_LOG_WARNING,
           "checkds: option is disabled");
    return false;
  }

  if (dspublish) {
    (void)dst_key_getnum(key, DST_NUM_DSPUBCOUNT, &count);
    count += 1;
    dst_key_setnum(key, DST_NUM_DSPUBCOUNT, count);
    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "checkds: %u DS published "
           "for key %u",
           count, dst_key_id(key));

    if (count != num) {
      return false;
    }
  } else {
    (void)dst_key_getnum(key, DST_NUM_DSDELCOUNT, &count);
    count += 1;
    dst_key_setnum(key, DST_NUM_DSDELCOUNT, count);
    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "checkds: %u DS withdrawn "
           "for key %u",
           count, dst_key_id(key));

    if (count != num) {
      return false;
    }
  }

  dns_zone_log(zone, ISC_LOG_DEBUG(3),
         "checkds: checkds %s for key "
         "%u",
         dspublish ? "published" : "withdrawn", dst_key_id(key));

  dns_zone_lock_keyfiles(zone);
  result = dns_keymgr_checkds_id(kasp, &zone->checkds_ok, now, now,
               dspublish, dst_key_id(key),
               dst_key_alg(key));
  dns_zone_unlock_keyfiles(zone);

  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_WARNING,
           "checkds: checkds for key %u failed: %s",
           dst_key_id(key), isc_result_totext(result));
    return false;
  }

  return true;
}

static isc_result_t
validate_ds(dns_zone_t *zone, dns_message_t *message) {
  UNUSED(zone);
  UNUSED(message);

  /* Get closest trust anchor */

  /* Check that trust anchor is (grand)parent of zone. */

  /* Find the DNSKEY signing the message. */

  /* Check that DNSKEY is in chain of trust. */

  /* Validate DS RRset. */

  return ISC_R_SUCCESS;
}

static void
checkds_done(void *arg) {
  dns_request_t *request = (dns_request_t *)arg;
  dns_checkds_t *checkds = dns_request_getarg(request);
  char addrbuf[ISC_SOCKADDR_FORMATSIZE];
  char rcode[128];
  dns_zone_t *zone = NULL;
  dns_db_t *db = NULL;
  dns_dbversion_t *version = NULL;
  dns_dnsseckeylist_t keys;
  dns_kasp_t *kasp = NULL;
  dns_message_t *message = NULL;
  dns_rdataset_t *ds_rrset = NULL;
  isc_buffer_t buf;
  isc_result_t result;
  isc_stdtime_t now;
  isc_time_t timenow;
  bool rekey = false;
  bool empty = false;

  REQUIRE(DNS_CHECKDS_VALID(checkds));

  zone = checkds->zone;

  ISC_LIST_INIT(keys);

  kasp = zone->kasp;
  INSIST(kasp != NULL);

  isc_buffer_init(&buf, rcode, sizeof(rcode));
  isc_sockaddr_format(&checkds->dst, addrbuf, sizeof(addrbuf));

  dns_zone_log(zone, ISC_LOG_DEBUG(1), "checkds: DS query to %s: done",
         addrbuf);

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE,
         &message);
  INSIST(message != NULL);

  CHECK(dns_request_getresult(request));
  CHECK(dns_request_getresponse(request, message,
              DNS_MESSAGEPARSE_PRESERVEORDER));
  CHECK(dns_rcode_totext(message->rcode, &buf));

  dns_zone_log(zone, ISC_LOG_DEBUG(3),
         "checkds: DS response from %s: %.*s", addrbuf,
         (int)buf.used, rcode);

  /* Validate response. */
  CHECK(validate_ds(zone, message));

  /* Check RCODE. */
  if (message->rcode != dns_rcode_noerror) {
    dns_zone_log(zone, ISC_LOG_NOTICE,
           "checkds: bad DS response from %s: %.*s", addrbuf,
           (int)buf.used, rcode);
    goto cleanup;
  }

  /* Make sure that either AA or RA bit is set. */
  if ((message->flags & DNS_MESSAGEFLAG_AA) == 0 &&
      (message->flags & DNS_MESSAGEFLAG_RA) == 0)
  {
    dns_zone_log(zone, ISC_LOG_NOTICE,
           "checkds: bad DS response from %s: expected AA or "
           "RA bit set",
           addrbuf);
    goto cleanup;
  }

  /* Lookup DS RRset. */

  MSG_SECTION_FOREACH(message, DNS_SECTION_ANSWER, name) {
    if (dns_name_compare(&zone->origin, name) != 0) {
      continue;
    }

    ISC_LIST_FOREACH(name->list, rdataset, link) {
      if (rdataset->type != dns_rdatatype_ds &&
          rdataset->type != dns_rdatatype_deleg)
      {
        goto next;
      }

      ds_rrset = rdataset;
      break;
    }

    if (ds_rrset != NULL) {
      break;
    }

  next:;
  }

  if (ds_rrset == NULL) {
    empty = true;
    dns_zone_log(zone, ISC_LOG_NOTICE,
           "checkds: empty DS response from %s", addrbuf);
  }

  timenow = isc_time_now();
  now = isc_time_seconds(&timenow);

  CHECK(dns_zone_getdb(zone, &db));
  dns_db_currentversion(db, &version);

  KASP_LOCK(kasp);
  LOCK_ZONE(zone);
  ISC_LIST_FOREACH(zone->checkds_ok, key, link) {
    bool alldone = false, found = false;
    bool checkdspub = false, checkdsdel = false, ksk = false;
    dst_key_state_t ds_state = DST_KEY_STATE_NA;
    isc_stdtime_t published = 0, withdrawn = 0;

    /* Is this key have the KSK role? */
    (void)dst_key_role(key->key, &ksk, NULL);
    if (!ksk) {
      continue;
    }

    /* Do we need to check the DS RRset for this key? */
    (void)dst_key_getstate(key->key, DST_KEY_DS, &ds_state);
    (void)dst_key_gettime(key->key, DST_TIME_DSPUBLISH, &published);
    (void)dst_key_gettime(key->key, DST_TIME_DSDELETE, &withdrawn);

    if (ds_state == DST_KEY_STATE_RUMOURED && published == 0) {
      checkdspub = true;
    } else if (ds_state == DST_KEY_STATE_UNRETENTIVE &&
         withdrawn == 0)
    {
      checkdsdel = true;
    }
    if (!checkdspub && !checkdsdel) {
      continue;
    }

    if (empty) {
      goto dswithdrawn;
    }

    /* Find the appropriate DS record. */
    DNS_RDATASET_FOREACH(ds_rrset) {
      dns_rdata_ds_t ds;
      dns_rdata_t dnskey = DNS_RDATA_INIT;
      dns_rdata_t dsrdata = DNS_RDATA_INIT;
      dns_rdata_t rdata = DNS_RDATA_INIT;
      isc_result_t r;
      unsigned char dsbuf[DNS_DS_BUFFERSIZE];
      unsigned char keybuf[DNS_RDATA_MAXLENGTH];

      dns_rdataset_current(ds_rrset, &rdata);
      r = dns_rdata_tostruct(&rdata, &ds);
      if (r != ISC_R_SUCCESS) {
        continue;
      }
      /* Check key tag and algorithm. */
      if (dst_key_id(key->key) != ds.key_tag) {
        continue;
      }
      if (dst_algorithm_tosecalg(dst_key_alg(key->key)) !=
          ds.algorithm)
      {
        continue;
      }
      /* Derive DS from DNSKEY, see if the rdata is equal. */
      make_dnskey(key->key, keybuf, sizeof(keybuf), &dnskey);
      r = dns_ds_buildrdata(&zone->origin, &dnskey,
                ds.digest_type, dsbuf,
                sizeof(dsbuf), &dsrdata);
      if (r != ISC_R_SUCCESS) {
        continue;
      }
      if (dns_rdata_compare(&rdata, &dsrdata) == 0) {
        found = true;
        if (checkdspub) {
          /* DS Published. */
          alldone = do_checkds(zone, key->key,
                   now, true);
          if (alldone) {
            rekey = true;
          }
        }
      }
    }

  dswithdrawn:
    /* DS withdrawn. */
    if (checkdsdel && !found) {
      alldone = do_checkds(zone, key->key, now, false);
      if (alldone) {
        rekey = true;
      }
    }
  }
  UNLOCK_ZONE(zone);
  KASP_UNLOCK(kasp);

  /* Rekey after checkds. */
  if (rekey) {
    dns_zone_rekey(zone, false, false);
  }

cleanup:
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "checkds: DS request failed: %s",
           isc_result_totext(result));
  }

  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }

  ISC_LIST_FOREACH(keys, key, link) {
    ISC_LIST_UNLINK(keys, key, link);
    dns_dnsseckey_destroy(dns_zone_getmctx(zone), &key);
  }

  checkds_destroy(checkds, false);
  dns_message_detach(&message);
}

static bool
checkds_isqueued(dns_zone_t *zone, dns_name_t *name, isc_sockaddr_t *addr,
     dns_tsigkey_t *key, dns_transport_t *transport) {
  ISC_LIST_FOREACH(zone->checkds_requests, checkds, link) {
    if (checkds->request != NULL) {
      continue;
    }
    if (name != NULL && dns_name_equal(name, &checkds->ns)) {
      return true;
    }
    if (addr != NULL && isc_sockaddr_equal(addr, &checkds->dst) &&
        checkds->key == key && checkds->transport == transport)
    {
      return true;
    }
  }
  return false;
}

static void
checkds_create(isc_mem_t *mctx, unsigned int flags, dns_checkds_t **checkdsp) {
  dns_checkds_t *checkds;

  REQUIRE(checkdsp != NULL && *checkdsp == NULL);

  checkds = isc_mem_get(mctx, sizeof(*checkds));
  *checkds = (dns_checkds_t){
    .magic = CHECKDS_MAGIC,
    .flags = flags,
    .link = ISC_LINK_INITIALIZER,
    .mctx = isc_mem_ref(mctx),
    .ns = DNS_NAME_INITEMPTY,
  };

  isc_sockaddr_any(&checkds->dst);

  *checkdsp = checkds;
}

static void
checkds_createmessage(dns_zone_t *zone, dns_message_t **messagep) {
  dns_message_t *message = NULL;

  dns_linkedname_t *tempname = NULL;
  dns_rdataset_t *temprdataset = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(messagep != NULL && *messagep == NULL);

  dns_message_create(zone->mctx, NULL, NULL, DNS_MESSAGE_INTENTRENDER,
         &message);

  message->opcode = dns_opcode_query;
  message->rdclass = zone->rdclass;
  message->flags |= DNS_MESSAGEFLAG_RD;

  dns_message_gettempname(message, &tempname);

  dns_message_gettemprdataset(message, &temprdataset);

  /*
   * Make question.
   */
  dns_name_init(dns_name(tempname));
  dns_name_clone(&zone->origin, dns_name(tempname));
  dns_rdataset_makequestion(temprdataset, zone->rdclass,
          dns_rdatatype_ds);
  ISC_LIST_APPEND(tempname->list, temprdataset, link);
  dns_message_addname(message, tempname, DNS_SECTION_QUESTION);
  tempname = NULL;
  temprdataset = NULL;

  *messagep = message;
}

/*
 * XXXAG should check for DNS_ZONEFLG_EXITING
 */
static void
process_checkds_adb_event(void *arg) {
  dns_adbfind_t *find = (dns_adbfind_t *)arg;
  dns_checkds_t *checkds = (dns_checkds_t *)find->cbarg;
  dns_adbstatus_t astat = find->status;

  REQUIRE(DNS_CHECKDS_VALID(checkds));
  REQUIRE(find == checkds->find);

  switch (astat) {
  case DNS_ADB_MOREADDRESSES:
    dns_adb_destroyfind(&checkds->find);
    checkds_find_address(checkds);
    return;

  case DNS_ADB_NOMOREADDRESSES:
    LOCK_ZONE(checkds->zone);
    checkds_send_tons(checkds);
    UNLOCK_ZONE(checkds->zone);
    break;

  default:
    break;
  }

  checkds_destroy(checkds, false);
}

static void
checkds_find_address(dns_checkds_t *checkds) {
  isc_result_t result;
  unsigned int options;
  dns_adb_t *adb = NULL;
  dns_view_t *view = NULL;

  REQUIRE(DNS_CHECKDS_VALID(checkds));

  view = checkds->zone->view;
  options = DNS_ADBFIND_WANTEVENT;
  if (isc_net_probeipv4() != ISC_R_DISABLED) {
    options |= DNS_ADBFIND_INET;
  }
  if (isc_net_probeipv6() != ISC_R_DISABLED) {
    options |= DNS_ADBFIND_INET6;
  }

  dns_view_getadb(view, &adb);
  if (adb == NULL) {
    goto destroy;
  }

  result = dns_adb_createfind(
    adb, checkds->zone->loop, process_checkds_adb_event, checkds,
    &checkds->ns, options, 0, checkds->zone->view->dstport, 0, NULL,
    NULL, NULL, view->max_delegation_servers, &checkds->find, NULL);
  dns_adb_detach(&adb);

  /* Something failed? */
  if (result != ISC_R_SUCCESS) {
    goto destroy;
  }

  /* More addresses pending? */
  if ((checkds->find->options & DNS_ADBFIND_WANTEVENT) != 0) {
    return;
  }

  /* We have as many addresses as we can get. */
  LOCK_ZONE(checkds->zone);
  checkds_send_tons(checkds);
  UNLOCK_ZONE(checkds->zone);

destroy:
  checkds_destroy(checkds, false);
}

static void
checkds_send_toaddr(void *arg) {
  dns_checkds_t *checkds = (dns_checkds_t *)arg;
  isc_result_t result;
  dns_message_t *message = NULL;
  isc_netaddr_t dstip;
  dns_tsigkey_t *key = NULL;
  char addrbuf[ISC_SOCKADDR_FORMATSIZE];
  isc_sockaddr_t src;
  unsigned int options;
  bool have_checkdssource = false;
  bool canceled = checkds->rlevent->canceled;
  isc_tlsctx_cache_t *zmgr_tlsctx_cache = NULL;

  REQUIRE(DNS_CHECKDS_VALID(checkds));

  isc_rlevent_free(&checkds->rlevent);

  LOCK_ZONE(checkds->zone);

  if (DNS_ZONE_FLAG(checkds->zone, DNS_ZONEFLG_LOADED) == 0 || canceled ||
      DNS_ZONE_FLAG(checkds->zone, DNS_ZONEFLG_EXITING) ||
      checkds->zone->view->requestmgr == NULL ||
      checkds->zone->db == NULL)
  {
    CLEANUP(ISC_R_CANCELED);
  }

  /*
   * The raw IPv4 address should also exist.  Don't send to the
   * mapped form.
   */
  if (isc_sockaddr_pf(&checkds->dst) == PF_INET6 &&
      IN6_IS_ADDR_V4MAPPED(&checkds->dst.type.sin6.sin6_addr))
  {
    isc_sockaddr_format(&checkds->dst, addrbuf, sizeof(addrbuf));
    dns_zone_log(checkds->zone, ISC_LOG_DEBUG(3),
           "checkds: ignoring IPv6 mapped IPV4 address: %s",
           addrbuf);
    CLEANUP(ISC_R_CANCELED);
  }

  isc_netaddr_fromsockaddr(&dstip, &checkds->dst);

  checkds_createmessage(checkds->zone, &message);

  isc_sockaddr_format(&checkds->dst, addrbuf, sizeof(addrbuf));
  if (checkds->key != NULL) {
    /* Transfer ownership of key */
    key = checkds->key;
    checkds->key = NULL;
  } else {
    result = dns_view_getpeertsig(checkds->zone->view, &dstip,
                &key);
    if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
      dns_zone_log(checkds->zone, ISC_LOG_ERROR,
             "checkds: DS query to %s not sent. "
             "Peer TSIG key lookup failure.",
             addrbuf);
      goto cleanup_message;
    }
  }

  if (key != NULL) {
    char namebuf[DNS_NAME_FORMATSIZE];

    dns_name_format(key->name, namebuf, sizeof(namebuf));
    dns_zone_log(checkds->zone, ISC_LOG_DEBUG(3),
           "checkds: sending DS query to %s : TSIG (%s)",
           addrbuf, namebuf);
  } else {
    dns_zone_log(checkds->zone, ISC_LOG_DEBUG(3),
           "checkds: sending DS query to %s", addrbuf);
  }
  options = 0;
  if (checkds->zone->view->peers != NULL) {
    dns_peer_t *peer = NULL;
    bool usetcp = false;
    result = dns_peerlist_peerbyaddr(checkds->zone->view->peers,
             &dstip, &peer);
    if (result == ISC_R_SUCCESS) {
      result = dns_peer_getquerysource(peer, &src);
      if (result == ISC_R_SUCCESS) {
        have_checkdssource = true;
      }
      result = dns_peer_getforcetcp(peer, &usetcp);
      if (result == ISC_R_SUCCESS && usetcp) {
        options |= DNS_FETCHOPT_TCP;
      }
    }
  }
  switch (isc_sockaddr_pf(&checkds->dst)) {
  case PF_INET:
    if (!have_checkdssource) {
      isc_sockaddr_t any;
      isc_sockaddr_any(&any);

      src = checkds->src;
      if (isc_sockaddr_equal(&src, &any)) {
        src = zone_addr4_tosockaddr(
          &checkds->zone->parentalsrc4);
      }
    }
    break;
  case PF_INET6:
    if (!have_checkdssource) {
      isc_sockaddr_t any;
      isc_sockaddr_any6(&any);

      src = checkds->src;
      if (isc_sockaddr_equal(&src, &any)) {
        src = zone_addr6_tosockaddr(
          &checkds->zone->parentalsrc6);
      }
    }
    break;
  default:
    result = ISC_R_NOTIMPLEMENTED;
    goto cleanup_key;
  }

  dns_zone_log(checkds->zone, ISC_LOG_DEBUG(3),
         "checkds: create request for DS query to %s", addrbuf);

  options |= DNS_REQUESTOPT_TCP;

  dns__zonemgr_tlsctx_attach(dns_g_zonemgr, &zmgr_tlsctx_cache);
  const unsigned int connect_timeout = isc_nm_getinitialtimeout() /
               MS_PER_SEC;

  result = dns_request_create(
    checkds->zone->view->requestmgr, message, &src, &checkds->dst,
    checkds->transport, zmgr_tlsctx_cache, options, key,
    connect_timeout, TCP_REQUEST_TIMEOUT, UDP_REQUEST_TIMEOUT,
    UDP_REQUEST_RETRIES, checkds->zone->loop, checkds_done, checkds,
    &checkds->request);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(checkds->zone, ISC_LOG_DEBUG(3),
           "checkds: dns_request_create() to %s failed: %s",
           addrbuf, isc_result_totext(result));
  }

  isc_tlsctx_cache_detach(&zmgr_tlsctx_cache);

cleanup_key:
  if (key != NULL) {
    dns_tsigkey_detach(&key);
  }
cleanup_message:
  dns_message_detach(&message);
cleanup:
  UNLOCK_ZONE(checkds->zone);
  if (result != ISC_R_SUCCESS) {
    checkds_destroy(checkds, false);
  }
}

static void
checkds_send_tons(dns_checkds_t *checkds) {
  isc_sockaddr_t dst;
  isc_result_t result;
  dns_checkds_t *newcheckds = NULL;
  dns_zone_t *zone = NULL;

  /*
   * Zone lock held by caller.
   */
  REQUIRE(DNS_CHECKDS_VALID(checkds));
  REQUIRE(LOCKED_ZONE(checkds->zone));

  zone = checkds->zone;

  if (DNS_ZONE_FLAG(checkds->zone, DNS_ZONEFLG_EXITING)) {
    return;
  }

  ISC_LIST_FOREACH(checkds->find->list, ai, publink) {
    dst = ai->sockaddr;
    if (checkds_isqueued(zone, NULL, &dst, NULL, NULL)) {
      continue;
    }

    newcheckds = NULL;
    checkds_create(checkds->mctx, 0, &newcheckds);
    zone_iattach(zone, &newcheckds->zone);
    ISC_LIST_APPEND(newcheckds->zone->checkds_requests, newcheckds,
        link);
    newcheckds->dst = dst;
    dns_name_dup(&checkds->ns, checkds->mctx, &newcheckds->ns);
    switch (isc_sockaddr_pf(&newcheckds->dst)) {
    case PF_INET:
      isc_sockaddr_any(&newcheckds->src);
      break;
    case PF_INET6:
      isc_sockaddr_any6(&newcheckds->src);
      break;
    default:
      UNREACHABLE();
    }

    CHECK(isc_ratelimiter_enqueue(
      dns_g_zonemgr->checkdsrl, newcheckds->zone->loop,
      checkds_send_toaddr, newcheckds, &newcheckds->rlevent));
    newcheckds = NULL;
  }

cleanup:
  if (newcheckds != NULL) {
    checkds_destroy(newcheckds, true);
  }
}

static void
checkds_send(dns_zone_t *zone) {
  dns_view_t *view = dns_zone_getview(zone);
  isc_result_t result;
  unsigned int flags = 0;
  unsigned int i = 0;

  /*
   * Zone lock held by caller.
   */
  REQUIRE(LOCKED_ZONE(zone));

  dns_zone_log(zone, ISC_LOG_DEBUG(3),
         "checkds: start sending DS queries to %u parentals",
         dns_remote_count(&zone->parentals));

  if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "checkds: abort, named exiting");
    return;
  }

  dns_remote_reset(&zone->parentals, false);
  while (!dns_remote_done(&zone->parentals)) {
    dns_tsigkey_t *key = NULL;
    dns_transport_t *transport = NULL;
    isc_sockaddr_t src, dst;
    dns_checkds_t *checkds = NULL;

    i++;

    dst = dns_remote_curraddr(&zone->parentals);
    if (isc_sockaddr_disabled(&dst)) {
      goto next;
    }

    if (dns_remote_keyname(&zone->parentals) != NULL) {
      dns_name_t *keyname =
        dns_remote_keyname(&zone->parentals);
      (void)dns_view_gettsig(view, keyname, &key);
    }

    if (dns_remote_tlsname(&zone->parentals) != NULL) {
      dns_name_t *tlsname =
        dns_remote_tlsname(&zone->parentals);
      result = dns_view_gettransport(view, DNS_TRANSPORT_TLS,
                   tlsname, &transport);
      if (result == ISC_R_SUCCESS) {
        dns_zone_logc(
          zone, DNS_LOGCATEGORY_XFER_IN,
          ISC_LOG_INFO,
          "got TLS configuration for checkds");
      } else {
        dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN,
                ISC_LOG_ERROR,
                "could not get TLS configuration "
                "for checkds: %s",
                isc_result_totext(result));
        if (key != NULL) {
          dns_tsigkey_detach(&key);
        }
        goto next;
      }
    }

    src = dns_remote_sourceaddr(&zone->parentals);
    INSIST(isc_sockaddr_pf(&src) == isc_sockaddr_pf(&dst));

    if (checkds_isqueued(zone, NULL, &dst, key, transport)) {
      dns_zone_log(zone, ISC_LOG_DEBUG(3),
             "checkds: DS query to parent "
             "%d is queued",
             i);
      if (key != NULL) {
        dns_tsigkey_detach(&key);
      }
      if (transport != NULL) {
        dns_transport_detach(&transport);
      }
      goto next;
    }

    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "checkds: create DS query for "
           "parent %d",
           i);

    checkds_create(zone->mctx, flags, &checkds);
    zone_iattach(zone, &checkds->zone);
    dns_name_dup(dns_rootname, checkds->mctx, &checkds->ns);
    checkds->src = src;
    checkds->dst = dst;

    INSIST(checkds->key == NULL);
    if (key != NULL) {
      checkds->key = key;
      key = NULL;
    }

    INSIST(checkds->transport == NULL);
    if (transport != NULL) {
      checkds->transport = transport;
      transport = NULL;
    }

    ISC_LIST_APPEND(zone->checkds_requests, checkds, link);
    result = isc_ratelimiter_enqueue(
      dns_g_zonemgr->checkdsrl, checkds->zone->loop,
      checkds_send_toaddr, checkds, &checkds->rlevent);
    if (result != ISC_R_SUCCESS) {
      dns_zone_log(zone, ISC_LOG_DEBUG(3),
             "checkds: send DS query to "
             "parent %d failed",
             i);
      checkds_destroy(checkds, true);
    }

  next:
    dns_remote_next(&zone->parentals, false);
  }
}

/*
 * Fetch NS records from parent zone.
 */
static isc_result_t
nsfetch_start(dns_zonefetch_t *fetch) {
  dns_nsfetch_t *nsfetch;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_NS);

  nsfetch = &fetch->fetchdata.nsfetch;

  /* Derive parent domain. Check for root domain. */
  if (!dns_name_belowroot(&nsfetch->pname)) {
    return ISC_R_NOTFOUND;
  }

  dns_name_split(&nsfetch->pname,
           dns_name_countlabels(&nsfetch->pname) - 1U, NULL,
           &nsfetch->pname);

  fetch->qtype = dns_rdatatype_ns;
  fetch->qname = &nsfetch->pname;

  return ISC_R_SUCCESS;
}

/*
 * Retry an NS RRset lookup, one level up. In other words, this function should
 * be called on an dns_nsfetch structure where the response yielded in a NODATA
 * response. This must be because there is an empty non-terminal inbetween the
 * child and parent zone.
 */
static void
nsfetch_continue(dns_zonefetch_t *fetch) {
  dns_zone_t *zone = fetch->zone;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_NS);

#ifdef ENABLE_AFL
  if (!dns_fuzzing_resolver) {
#endif /* ifdef ENABLE_AFL */
    LOCK_ZONE(zone);
    zone->fetchcount[ZONEFETCHTYPE_NS]++;

    dns_zonefetch_reschedule(fetch);

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "Creating parent NS fetch in "
           "nsfetch_continue()");
    }
    UNLOCK_ZONE(zone);
#ifdef ENABLE_AFL
  }
#endif /* ifdef ENABLE_AFL */
}

static void
nsfetch_cancel(dns_zonefetch_t *fetch) {
  dns_zone_t *zone;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_NS);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  zone = fetch->zone;

  zone->fetchcount[ZONEFETCHTYPE_NS]--;
}

static void
nsfetch_cleanup(dns_zonefetch_t *fetch) {
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_NS);
}

/*
 * An NS RRset has been fetched from the parent of a zone whose DS RRset needs
 * to be checked; scan the RRset and start sending queries to the parental
 * agents.
 */
static isc_result_t
nsfetch_checkds(dns_zonefetch_t *fetch, isc_result_t eresult) {
  dns_nsfetch_t *nsfetch;
  isc_result_t result = ISC_R_NOMORE;
  dns_zone_t *zone = NULL;
  dns_name_t *pname = NULL;
  char pnamebuf[DNS_NAME_FORMATSIZE];
  dns_rdataset_t *nsrrset = NULL;

  REQUIRE(fetch != NULL);
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_NS);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  nsfetch = &fetch->fetchdata.nsfetch;
  zone = fetch->zone;
  nsrrset = &fetch->rrset;
  pname = &nsfetch->pname;

  zone->fetchcount[ZONEFETCHTYPE_NS]--;

  dns_name_format(pname, pnamebuf, sizeof(pnamebuf));
  dnssec_log(zone, ISC_LOG_DEBUG(3),
       "Returned from '%s' NS fetch in nsfetch_checkds(): %s",
       pnamebuf, isc_result_totext(eresult));

  if (eresult == DNS_R_NCACHENXRRSET || eresult == DNS_R_NXRRSET) {
    dnssec_log(zone, ISC_LOG_DEBUG(3),
         "NODATA response for NS '%s', level up", pnamebuf);
    return DNS_R_CONTINUE;
  }

  CHECK(dns_zonefetch_verify(fetch, eresult, dns_trust_secure));

  /* Record the number of NS records we found. */
  zone->parent_nscount = dns_rdataset_count(nsrrset);

  UNLOCK_ZONE(zone);

  /* Look up the addresses for the found parental name servers. */
  DNS_RDATASET_FOREACH(nsrrset) {
    dns_checkds_t *checkds = NULL;
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_ns_t ns;
    bool isqueued;

    dns_rdataset_current(nsrrset, &rdata);
    result = dns_rdata_tostruct(&rdata, &ns);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    dns_rdata_reset(&rdata);

    LOCK_ZONE(zone);
    isqueued = checkds_isqueued(zone, &ns.name, NULL, NULL, NULL);
    UNLOCK_ZONE(zone);
    if (isqueued) {
      continue;
    }
    checkds_create(zone->mctx, 0, &checkds);

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      char nsnamebuf[DNS_NAME_FORMATSIZE];
      dns_name_format(&ns.name, nsnamebuf, sizeof(nsnamebuf));
      dns_zone_log(zone, ISC_LOG_DEBUG(3),
             "checkds: send DS query to NS %s",
             nsnamebuf);
    }

    LOCK_ZONE(zone);
    zone_iattach(zone, &checkds->zone);
    dns_name_dup(&ns.name, zone->mctx, &checkds->ns);
    ISC_LIST_APPEND(zone->checkds_requests, checkds, link);
    UNLOCK_ZONE(zone);

    checkds_find_address(checkds);
  }

  LOCK_ZONE(zone);

cleanup:
  if (result != ISC_R_SUCCESS) {
    dnssec_log(
      zone, ISC_LOG_ERROR,
      "checkds: error during parental-agents processing: %s",
      isc_result_totext(result));
  }

  return result;
}

static void
zone_checkds(dns_zone_t *zone) {
  bool cdscheck = false;
  dns_checkdstype_t checkdstype = zone->checkdstype;

  if (checkdstype == dns_checkdstype_no) {
    return;
  }

  ISC_LIST_FOREACH(zone->checkds_ok, key, link) {
    dst_key_state_t ds_state = DST_KEY_STATE_NA;
    bool ksk = false;
    isc_stdtime_t published = 0, withdrawn = 0;

    /* Is this key have the KSK role? */
    (void)dst_key_role(key->key, &ksk, NULL);
    if (!ksk) {
      continue;
    }

    /* Do we need to check the DS RRset? */
    (void)dst_key_getstate(key->key, DST_KEY_DS, &ds_state);
    (void)dst_key_gettime(key->key, DST_TIME_DSPUBLISH, &published);
    (void)dst_key_gettime(key->key, DST_TIME_DSDELETE, &withdrawn);

    if (ds_state == DST_KEY_STATE_RUMOURED && published == 0) {
      dst_key_setnum(key->key, DST_NUM_DSPUBCOUNT, 0);
      cdscheck = true;
    } else if (ds_state == DST_KEY_STATE_UNRETENTIVE &&
         withdrawn == 0)
    {
      dst_key_setnum(key->key, DST_NUM_DSDELCOUNT, 0);
      cdscheck = true;
    }
  }

  if (!cdscheck) {
    return;
  }

  if (checkdstype == dns_checkdstype_explicit) {
    /* Request the DS RRset. */
    LOCK_ZONE(zone);
    checkds_send(zone);
    UNLOCK_ZONE(zone);
    return;
  }

  INSIST(checkdstype == dns_checkdstype_yes);

#ifdef ENABLE_AFL
  if (!dns_fuzzing_resolver) {
#endif /* ifdef ENABLE_AFL */
    dns_zonefetch_t *fetch = NULL;
    dns_nsfetch_t *nsfetch = NULL;

    fetch = isc_mem_get(zone->mctx, sizeof(dns_zonefetch_t));
    *fetch = (dns_zonefetch_t){
      .zone = zone,
      .fetchtype = ZONEFETCHTYPE_NS,
      .fetchmethods =
        (dns_zonefetch_methods_t){
          .start_fetch = nsfetch_start,
          .continue_fetch = nsfetch_continue,
          .cancel_fetch = nsfetch_cancel,
          .cleanup_fetch = nsfetch_cleanup,
          .done_fetch = nsfetch_checkds,
        },
    };
    isc_mem_attach(zone->mctx, &fetch->mctx);

    LOCK_ZONE(zone);
    zone->fetchcount[ZONEFETCHTYPE_NS]++;

    nsfetch = &fetch->fetchdata.nsfetch;
    dns_name_init(&nsfetch->pname);
    dns_name_clone(&zone->origin, &nsfetch->pname);

    dns_zonefetch_schedule(fetch, &zone->origin);

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      dnssec_log(
        zone, ISC_LOG_DEBUG(3),
        "Creating parent NS fetch in zone_checkds()");
    }
    UNLOCK_ZONE(zone);
#ifdef ENABLE_AFL
  }
#endif /* ifdef ENABLE_AFL */
}

static unsigned char _dsync_data[] = "\x06_dsync";
static dns_name_t _dsync = DNS_NAME_INITNONABSOLUTE(_dsync_data);

static isc_result_t
dsyncfetch_start(dns_zonefetch_t *fetch) {
  dns_dsyncfetch_t *dsyncfetch;
  dns_zone_t *zone;
  dns_name_t *dsyncname, prefix;
  unsigned int nlabels;
  isc_result_t result;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_DSYNC);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));

  dsyncfetch = &fetch->fetchdata.dsyncfetch;
  zone = fetch->zone;

  /*
   * The dsync owner name is build up of <prefix>._dsync.<parent-name>.
   * The prefix is the relative domain name of the child consisting of
   * the labels under the zonecut.
   */
  dsyncname = dns_fixedname_initname(&dsyncfetch->dsyncname);

  nlabels = dns_name_countlabels(&dsyncfetch->pname);
  dns_name_init(&prefix);
  dns_name_split(dns_name(&fetch->name), nlabels, &prefix, NULL);

  result = dns_name_concatenate(&prefix, &_dsync, dsyncname);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "dsyncfetch: failed to create parent DSYNC fetch "
         "(child part): %s",
         isc_result_totext(result));
    return result;
  }

  result = dns_name_concatenate(dsyncname, &dsyncfetch->pname, dsyncname);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "dsyncfetch: failed to create parent DSYNC fetch "
         "(parent part): %s",
         isc_result_totext(result));
    return result;
  }

  fetch->qtype = dns_rdatatype_dsync;
  fetch->qname = dsyncname;

  return ISC_R_SUCCESS;
}

/*
 * Retry an DSYNC RRset lookup.
 */
static void
dsyncfetch_continue(dns_zonefetch_t *fetch) {
  dns_zone_t *zone;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_DSYNC);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));

  zone = fetch->zone;

#ifdef ENABLE_AFL
  if (!dns_fuzzing_resolver) {
#endif /* ifdef ENABLE_AFL */
    LOCK_ZONE(zone);
    zone->fetchcount[ZONEFETCHTYPE_DSYNC]++;

    dns_zonefetch_reschedule(fetch);

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "Creating parent DSYNC fetch in "
           "dsyncfetch_continue()");
    }
    UNLOCK_ZONE(zone);
#ifdef ENABLE_AFL
  }
#endif /* ifdef ENABLE_AFL */
}

static void
dsyncfetch_cancel(dns_zonefetch_t *fetch) {
  dns_zone_t *zone;

  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_DSYNC);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  zone = fetch->zone;

  zone->fetchcount[ZONEFETCHTYPE_DSYNC]--;
}

static void
dsyncfetch_cleanup(dns_zonefetch_t *fetch) {
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_DSYNC);
}

/*
 * A DSYNC RRset has been fetched; scan the RRset and start sending
 * NOTIFY(CDS) queries to them.
 */
static isc_result_t
dsyncfetch_done(dns_zonefetch_t *fetch, isc_result_t eresult) {
  dns_dsyncfetch_t *dsyncfetch;
  isc_result_t result = ISC_R_NOMORE;
  dns_notify_t *notify = NULL;
  dns_zone_t *zone = NULL;
  dns_name_t *dsyncname = NULL;
  char dsyncnamebuf[DNS_NAME_FORMATSIZE];
  dns_rdataset_t *rrset = NULL;
  in_port_t port = 0;
  dns_fixedname_t fixed;
  dns_name_t *target = dns_fixedname_initname(&fixed);

  REQUIRE(fetch != NULL);
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_DSYNC);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  dsyncfetch = &fetch->fetchdata.dsyncfetch;
  zone = fetch->zone;
  rrset = &fetch->rrset;
  dsyncname = dns_name(&dsyncfetch->dsyncname);

  zone->fetchcount[ZONEFETCHTYPE_DSYNC]--;

  dns_name_format(dsyncname, dsyncnamebuf, sizeof(dsyncnamebuf));
  dns_zone_log(zone, ISC_LOG_DEBUG(3),
         "dsyncfetch: Returned from '%s' DSYNC fetch in "
         "dsyncfetch_done(): %s",
         dsyncnamebuf, isc_result_totext(eresult));

  result = dns_zonefetch_verify(fetch, eresult, dns_trust_secure);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

  UNLOCK_ZONE(zone);

  /* Notify targets. */
  dns_rdata_dsync_t dsync;
  unsigned int count = 0;
  for (result = dns_rdataset_first(rrset); result == ISC_R_SUCCESS;
       result = dns_rdataset_next(rrset))
  {
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(rrset, &rdata);
    result = dns_rdata_tostruct(&rdata, &dsync);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);

    dns_rdata_reset(&rdata);
    if (dsync.scheme != DNS_DSYNCSCHEME_NOTIFY) {
      dns_zone_log(zone, ISC_LOG_DEBUG(1),
             "dsyncfetch: unsupported DSYNC scheme %u, "
             "ignoring",
             dsync.scheme);
      continue;
    }

    if (dsync.type != dns_rdatatype_cds) {
      char typebuf[DNS_RDATATYPE_FORMATSIZE];
      dns_rdatatype_format(dsync.type, typebuf,
               sizeof(typebuf));

      dns_zone_log(zone, ISC_LOG_DEBUG(1),
             "dsyncfetch: DSYNC RRtype %s not "
             "supported, ignoring",
             result == ISC_R_SUCCESS ? typebuf
                   : "UNKNOWN");
      continue;
    }

    /* Save matched DSYNC record. */
    if (count == 0) {
      port = dsync.port;
      dns_name_copy(&dsync.target, target);
    }

    count++;
    if (count > 1) {
      dns_zone_log(zone, ISC_LOG_WARNING,
             "dsyncfetch: multiple DSYNC records "
             "matching NOTIFY scheme and CDS RRtype, "
             "dropping response");
      result = DNS_R_INVALIDDSYNC;
      break;
    }
  }

  LOCK_ZONE(zone);

  if (result == ISC_R_NOMORE) {
    result = ISC_R_SUCCESS;
  } else {
    /* We didn't scan the complete RRset. */
    goto done;
  }

  /*
   * Only one NOTIFY can be queued per type.
   * Currently the only supported scheme/type is NOTIFY CDS.
   * The port and target from the first matched DSYNC record are saved in
   * 'port' and 'target'.
   */
  if (count != 1) {
    /*
     * Either count equals zero, and there is nothing to be queued.
     * Or count > 1, then this is an invalid DSYNC RRset.
     */
    goto done;
  }

  bool isqueued = dns_notify_isqueued(&zone->notifycds, dns_rdatatype_cds,
              port, 0, target, NULL, NULL, NULL);

  UNLOCK_ZONE(zone);

  if (!isqueued) {
    dns_notify_create(zone->mctx, dns_rdatatype_cds, port,
          DNS_NOTIFY_NOSOA, &notify);
    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      char tbuf[DNS_NAME_FORMATSIZE];
      dns_name_format(target, tbuf, sizeof(tbuf));
      dns_zone_log(zone, ISC_LOG_DEBUG(3),
             "dsyncfetch: send NOTIFY(CDS) query to %s",
             tbuf);
    }
    dns_zone_iattach(zone, &notify->zone);
    dns_name_dup(target, zone->mctx, &notify->ns);
    LOCK_ZONE(zone);
    ISC_LIST_APPEND(zone->notifycds.notifies, notify, link);
    UNLOCK_ZONE(zone);
    dns_notify_find_address(notify);
  }

  LOCK_ZONE(zone);

done:
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_DEBUG(3),
           "dsyncfetch: error processing DSYNC RRset: %s",
           isc_result_totext(result));
  }

  return result;
}

/*
 * An NS RRset has been fetched from the parent of a zone whose DSYNC RRset
 * needs to be queried; scan the RRset and start resolving those queries.
 */
static isc_result_t
nsfetch_dsync(dns_zonefetch_t *fetch, isc_result_t eresult) {
  dns_nsfetch_t *nsfetch;
  isc_result_t result = ISC_R_NOMORE;
  dns_zone_t *zone = NULL;
  dns_name_t *pname = NULL;
  char pnamebuf[DNS_NAME_FORMATSIZE];

  REQUIRE(fetch != NULL);
  REQUIRE(fetch->fetchtype == ZONEFETCHTYPE_NS);
  REQUIRE(DNS_ZONE_VALID(fetch->zone));
  REQUIRE(LOCKED_ZONE(fetch->zone));

  nsfetch = &fetch->fetchdata.nsfetch;
  zone = fetch->zone;
  pname = &nsfetch->pname;

  zone->fetchcount[ZONEFETCHTYPE_NS]--;

  dns_name_format(pname, pnamebuf, sizeof(pnamebuf));
  dnssec_log(zone, ISC_LOG_DEBUG(3),
       "Returned from '%s' NS fetch in nsfetch_dsync(): %s",
       pnamebuf, isc_result_totext(eresult));

  if (eresult == DNS_R_NCACHENXRRSET || eresult == DNS_R_NXRRSET) {
    dnssec_log(zone, ISC_LOG_DEBUG(3),
         "NODATA response for NS '%s', level up", pnamebuf);
    return DNS_R_CONTINUE;
  }

  result = dns_zonefetch_verify(fetch, eresult, dns_trust_secure);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

#ifdef ENABLE_AFL
  if (!dns_fuzzing_resolver) {
#endif /* ifdef ENABLE_AFL */
    dns_zonefetch_t *zfetch = NULL;
    dns_dsyncfetch_t *dsyncfetch;

    zfetch = isc_mem_get(zone->mctx, sizeof(dns_zonefetch_t));
    *zfetch = (dns_zonefetch_t){
      .zone = zone,
      .fetchtype = ZONEFETCHTYPE_DSYNC,
      .fetchmethods =
        (dns_zonefetch_methods_t){
          .start_fetch = dsyncfetch_start,
          .continue_fetch = dsyncfetch_continue,
          .cancel_fetch = dsyncfetch_cancel,
          .cleanup_fetch = dsyncfetch_cleanup,
          .done_fetch = dsyncfetch_done,
        },
    };
    isc_mem_attach(zone->mctx, &zfetch->mctx);

    zone->fetchcount[ZONEFETCHTYPE_DSYNC]++;

    dsyncfetch = &zfetch->fetchdata.dsyncfetch;
    dns_name_init(&dsyncfetch->pname);
    dns_name_clone(pname, &dsyncfetch->pname);

    dns_zonefetch_schedule(zfetch, &zone->origin);

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "Creating parent DSYNC fetch in "
           "nsfetch_dsync()");
    }
#ifdef ENABLE_AFL
  }
#endif /* ifdef ENABLE_AFL */

done:
  return result;
}

static void
zone_notifycds(dns_zone_t *zone) {
  dns_notifytype_t notifytype = zone->notifycds.notifytype;

  if (notifytype == dns_notifytype_no) {
    return;
  }

  INSIST(notifytype == dns_notifytype_yes);

#ifdef ENABLE_AFL
  if (!dns_fuzzing_resolver) {
#endif /* ifdef ENABLE_AFL */
    dns_zonefetch_t *fetch = NULL;
    dns_nsfetch_t *nsfetch;

    fetch = isc_mem_get(zone->mctx, sizeof(dns_zonefetch_t));
    *fetch = (dns_zonefetch_t){
      .zone = zone,
      .fetchtype = ZONEFETCHTYPE_NS,
      .fetchmethods =
        (dns_zonefetch_methods_t){
          .start_fetch = nsfetch_start,
          .continue_fetch = nsfetch_continue,
          .cancel_fetch = nsfetch_cancel,
          .cleanup_fetch = nsfetch_cleanup,
          .done_fetch = nsfetch_dsync,
        },
    };
    isc_mem_attach(zone->mctx, &fetch->mctx);

    LOCK_ZONE(zone);
    zone->fetchcount[ZONEFETCHTYPE_NS]++;

    nsfetch = &fetch->fetchdata.nsfetch;
    dns_name_init(&nsfetch->pname);
    dns_name_clone(&zone->origin, &nsfetch->pname);

    dns_zonefetch_schedule(fetch, &zone->origin);

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      dnssec_log(
        zone, ISC_LOG_DEBUG(3),
        "Creating parent NS fetch in zone_notifyds()");
    }
    UNLOCK_ZONE(zone);
#ifdef ENABLE_AFL
  }
#endif /* ifdef ENABLE_AFL */
}

static void
update_ttl(dns_rdataset_t *rdataset, dns_name_t *name, dns_ttl_t ttl,
     dns_diff_t *diff) {
  dns_diff_t pending;

  dns_diff_init(diff->mctx, &pending);

  /*
   * Delete everything using the existing TTL.
   */
  DNS_RDATASET_FOREACH(rdataset) {
    dns_difftuple_t *tuple = NULL;
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(rdataset, &rdata);
    dns_difftuple_create(diff->mctx, DNS_DIFFOP_DEL, name,
             rdataset->ttl, &rdata, &tuple);
    dns_diff_append(&pending, &tuple);
  }

  /*
   * Add everything using the new TTL.
   */
  DNS_RDATASET_FOREACH(rdataset) {
    dns_difftuple_t *tuple = NULL;
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(rdataset, &rdata);
    dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD, name, ttl,
             &rdata, &tuple);
    dns_diff_append(&pending, &tuple);
  }
  dns_diff_appendlistminimal(diff, &pending);
}

static isc_result_t
zone_verifykeys(dns_zone_t *zone, dns_dnsseckeylist_t *newkeys,
    uint32_t purgeval, isc_stdtime_t now) {
  /*
   * Make sure that the existing keys are also present in the new keylist.
   */
  ISC_LIST_FOREACH(zone->keyring, key1, link) {
    bool found = false;

    if (dst_key_is_unused(key1->key)) {
      continue;
    }
    if (dns_keymgr_key_may_be_purged(key1->key, purgeval, now)) {
      continue;
    }
    if (key1->purge) {
      continue;
    }

    ISC_LIST_FOREACH(*newkeys, key2, link) {
      if (dst_key_compare(key1->key, key2->key)) {
        found = true;
        break;
      }
    }

    if (!found) {
      char keystr[DST_KEY_FORMATSIZE];
      dst_key_format(key1->key, keystr, sizeof(keystr));
      dnssec_log(zone, ISC_LOG_DEBUG(1),
           "verifykeys: key %s - not available",
           keystr);
      return ISC_R_NOTFOUND;
    }
  }

  /* All good. */
  return ISC_R_SUCCESS;
}

static void
remove_rdataset(dns_zone_t *zone, dns_diff_t *diff, dns_rdataset_t *rdataset) {
  if (!dns_rdataset_isassociated(rdataset)) {
    return;
  }

  DNS_RDATASET_FOREACH(rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_difftuple_t *tuple = NULL;

    dns_rdataset_current(rdataset, &rdata);
    dns_difftuple_create(zone->mctx, DNS_DIFFOP_DEL, &zone->origin,
             rdataset->ttl, &rdata, &tuple);
    dns_diff_append(diff, &tuple);
  }
  return;
}

static void
add_tuple(dns_diff_t *diff, dns_difftuple_t *tuple) {
  dns_difftuple_t *copy = NULL;

  dns_difftuple_copy(tuple, &copy);
  dns_diff_append(diff, &copy);
}

static void
zone_apply_skrbundle(dns_zone_t *zone, dns_skrbundle_t *bundle,
         dns_rdataset_t *dnskeyset, dns_rdataset_t *cdsset,
         dns_rdataset_t *cdnskeyset, dns_diff_t *diff) {
  dns_kasp_t *kasp = zone->kasp;
  dns_diff_t pending;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(DNS_KASP_VALID(kasp));
  REQUIRE(DNS_SKRBUNDLE_VALID(bundle));
  dns_diff_init(diff->mctx, &pending);

  /* Remove existing DNSKEY, CDS, and CDNSKEY records. */
  remove_rdataset(zone, diff, dnskeyset);
  remove_rdataset(zone, diff, cdsset);
  remove_rdataset(zone, diff, cdnskeyset);

  /* Add the records from the bundle. */
  ISC_LIST_FOREACH(bundle->diff.tuples, tuple, link) {
    switch (tuple->rdata.type) {
    case dns_rdatatype_dnskey:
      add_tuple(&pending, tuple);
      break;
    case dns_rdatatype_cdnskey:
    case dns_rdatatype_cds:
      add_tuple(&pending, tuple);
      break;
    case dns_rdatatype_rrsig:
      /* Not interested in right now */
      break;
    default:
      INSIST(0);
    }
  }
  if (!ISC_LIST_EMPTY(pending.tuples)) {
    dns_diff_appendlistminimal(diff, &pending);
  }
}

static void
zone_rekey(dns_zone_t *zone) {
  isc_result_t result;
  dns_db_t *db = NULL;
  dns_dbnode_t *node = NULL;
  dns_dbversion_t *ver = NULL;
  dns_rdataset_t cdsset, soaset, soasigs, keyset, keysigs, cdnskeyset;
  dns_dnsseckeylist_t dnskeys, keys, rmkeys;
  dns_diff_t diff, _sig_diff;
  dns_kasp_t *kasp;
  dns_skrbundle_t *bundle = NULL;
  dns__zonediff_t zonediff;
  bool commit = false, newactive = false;
  bool newalg = false;
  bool fullsign;
  bool notifycds = false;
  bool offlineksk = false;
  bool keymgr_done = false;
  bool kasp_change = false;
  uint8_t options = 0;
  uint32_t sigval = 0;
  dns_ttl_t ttl = 3600;
  const char *dir = NULL;
  isc_mem_t *mctx = NULL;
  isc_stdtime_t now, nexttime = 0;
  isc_time_t timenow;
  isc_interval_t ival;
  char timebuf[80];

  REQUIRE(DNS_ZONE_VALID(zone));

  ISC_LIST_INIT(dnskeys);
  ISC_LIST_INIT(keys);
  ISC_LIST_INIT(rmkeys);
  dns_rdataset_init(&soaset);
  dns_rdataset_init(&soasigs);
  dns_rdataset_init(&keyset);
  dns_rdataset_init(&keysigs);
  dns_rdataset_init(&cdsset);
  dns_rdataset_init(&cdnskeyset);
  mctx = zone->mctx;
  dns_diff_init(mctx, &diff);
  dns_diff_init(mctx, &_sig_diff);
  zonediff_init(&zonediff, &_sig_diff);

  CHECK(dns_zone_getdb(zone, &db));
  CHECK(dns_db_newversion(db, &ver));
  CHECK(dns_db_getoriginnode(db, &node));

  timenow = isc_time_now();
  now = isc_time_seconds(&timenow);

  kasp = zone->kasp;
  dir = dns_zone_getkeydirectory(zone);

  dnssec_log(zone, ISC_LOG_INFO, "reconfiguring zone keys");

  /* Get the SOA record's TTL */
  CHECK(dns_db_findrdataset(db, node, ver, dns_rdatatype_soa,
          dns_rdatatype_none, 0, &soaset, &soasigs));
  ttl = soaset.ttl;
  dns_rdataset_disassociate(&soaset);

  if (kasp != NULL) {
    ttl = dns_kasp_dnskeyttl(kasp);
    offlineksk = dns_kasp_offlineksk(kasp);
    sigval = dns_kasp_sigvalidity_dnskey(kasp);
  }

  /* Get the current DNSKEY rdataset */
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey,
             dns_rdatatype_none, 0, &keyset, &keysigs);
  if (result == ISC_R_SUCCESS) {
    /*
     * If we don't have a policy then use the DNSKEY ttl
     * if it exists.  Otherwise update the DNSKEY ttl if
     * needed.
     */
    if (kasp == NULL) {
      ttl = keyset.ttl;
    } else if (ttl != keyset.ttl && !offlineksk) {
      update_ttl(&keyset, &zone->origin, ttl, &diff);
      dnssec_log(zone, ISC_LOG_INFO,
           "Updating DNSKEY TTL from %u to %u",
           keyset.ttl, ttl);
      keyset.ttl = ttl;
    }

    dns_zone_lock_keyfiles(zone);

    result = dns_dnssec_keylistfromrdataset(
      &zone->origin, kasp, dir, mctx, &keyset, &keysigs,
      &soasigs, false, false, &dnskeys);

    dns_zone_unlock_keyfiles(zone);

    CHECK(result);
  } else if (result != ISC_R_NOTFOUND) {
    goto cleanup;
  }

  /* Get the current CDS rdataset */
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_cds,
             dns_rdatatype_none, 0, &cdsset, NULL);
  if (result != ISC_R_SUCCESS) {
    dns_rdataset_cleanup(&cdsset);
  } else if (kasp != NULL && ttl != cdsset.ttl && !offlineksk) {
    update_ttl(&cdsset, &zone->origin, ttl, &diff);
    dnssec_log(zone, ISC_LOG_INFO, "Updating CDS TTL from %u to %u",
         cdsset.ttl, ttl);
    cdsset.ttl = ttl;
  }

  /* Get the current CDNSKEY rdataset */
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_cdnskey,
             dns_rdatatype_none, 0, &cdnskeyset, NULL);
  if (result != ISC_R_SUCCESS) {
    dns_rdataset_cleanup(&cdnskeyset);
  } else if (kasp != NULL && ttl != cdnskeyset.ttl && !offlineksk) {
    update_ttl(&cdnskeyset, &zone->origin, ttl, &diff);
    dnssec_log(zone, ISC_LOG_INFO,
         "Updating CDNSKEY TTL from %u to %u", cdnskeyset.ttl,
         ttl);
    cdnskeyset.ttl = ttl;
  }

  /*
   * True when called from "rndc sign".  Indicates the zone should be
   * fully signed now.
   */
  fullsign = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FULLSIGN);
  if (fullsign) {
    options |= DNS_KEYMGRATTR_FULLSIGN;
  }

  /*
   * True when called from "rndc dnssec -step". Indicates the zone
   * is allowed to do the next step(s) in the keymgr process.
   */
  if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FORCEKEYMGR)) {
    options |= DNS_KEYMGRATTR_FORCESTEP;
  }

  if (offlineksk) {
    /* Lookup the correct bundle in the SKR. */
    LOCK_ZONE(zone);
    if (zone->skr == NULL) {
      UNLOCK_ZONE(zone);
      dnssec_log(zone, ISC_LOG_DEBUG(1),
           "zone_rekey:dns_skr_lookup failed: "
           "no SKR available");
      CLEANUP(DNS_R_NOSKRFILE);
    }
    bundle = dns_skr_lookup(zone->skr, now, sigval);
    zone->skrbundle = bundle;
    UNLOCK_ZONE(zone);

    if (bundle == NULL) {
      char nowstr[26]; /* Minimal buf per ctime_r() spec. */
      char utc[sizeof("YYYYMMDDHHSSMM")];
      isc_buffer_t b;
      isc_region_t r;
      isc_buffer_init(&b, utc, sizeof(utc));

      isc_stdtime_tostring(now, nowstr, sizeof(nowstr));
      (void)dns_time32_totext(now, &b);
      isc_buffer_usedregion(&b, &r);
      dnssec_log(zone, ISC_LOG_DEBUG(1),
           "zone_rekey:dns_skr_lookup failed: "
           "no available SKR bundle for time "
           "%.*s (%s)",
           (int)r.length, r.base, nowstr);
      CLEANUP(DNS_R_NOSKRBUNDLE);
    }

    zone_apply_skrbundle(zone, bundle, &keyset, &cdsset,
             &cdnskeyset, &diff);

    dns_skrbundle_t *next = ISC_LIST_NEXT(bundle, link);
    if (next != NULL) {
      if (nexttime == 0) {
        nexttime = next->inception;
      }
    } else {
      dnssec_log(zone, ISC_LOG_WARNING,
           "zone_rekey: last bundle in skr, please "
           "import new skr file");
    }
  }

  /*
   * DNSSEC Key and Signing Policy
   */

  KASP_LOCK(kasp);

  dns_zone_lock_keyfiles(zone);
  result = dns_dnssec_findmatchingkeys(&zone->origin, kasp, dir,
               dns_zone_getkeystores(zone), now,
               false, mctx, &keys);
  dns_zone_unlock_keyfiles(zone);

  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_DEBUG(1),
         "zone_rekey:dns_dnssec_findmatchingkeys failed: %s",
         isc_result_totext(result));
  }

  if (kasp != NULL && !offlineksk) {
    /* Verify new keys. */
    isc_result_t ret = zone_verifykeys(
      zone, &keys, dns_kasp_purgekeys(kasp), now);
    if (ret != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_rekey:zone_verifykeys failed: "
           "some key files are missing");
      KASP_UNLOCK(kasp);
      goto cleanup;
    }

    /*
     * Check DS at parental agents. Clear ongoing checks.
     */
    LOCK_ZONE(zone);
    checkds_cancel(zone);
    clear_keylist(&zone->checkds_ok, zone->mctx);
    ISC_LIST_INIT(zone->checkds_ok);
    UNLOCK_ZONE(zone);

    ret = dns_zone_getdnsseckeys(zone, db, ver, now,
               &zone->checkds_ok);
    if (ret == ISC_R_SUCCESS) {
      zone_checkds(zone);
    } else {
      dnssec_log(zone,
           (ret == ISC_R_NOTFOUND) ? ISC_LOG_DEBUG(1)
                 : ISC_LOG_ERROR,
           "zone_rekey:dns_zone_getdnsseckeys failed: "
           "%s",
           isc_result_totext(ret));
    }

    /* Run keymgr. */
    if (result == ISC_R_SUCCESS || result == ISC_R_NOTFOUND) {
      dns_zone_lock_keyfiles(zone);
      result = dns_keymgr_run(&zone->origin, zone->rdclass,
            mctx, &keys, &dnskeys, dir,
            kasp, options, now, &nexttime);
      dns_zone_unlock_keyfiles(zone);

      if (result == ISC_R_SUCCESS) {
        kasp_change = true;
        keymgr_done = true;
      } else if (result == DNS_R_UNCHANGED) {
        result = ISC_R_SUCCESS;
        keymgr_done = true;
      } else {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_rekey:dns_keymgr_run "
             "failed: %s",
             isc_result_totext(result));
        KASP_UNLOCK(kasp);
        goto cleanup;
      }
    }
  } else if (offlineksk) {
    /*
     * With offline-ksk enabled we don't run the keymgr.
     * Instead we derive the states from the timing metadata.
     */
    dns_zone_lock_keyfiles(zone);
    result = dns_keymgr_offline(&zone->origin, &keys, kasp, now,
              &nexttime);
    dns_zone_unlock_keyfiles(zone);

    if (result == ISC_R_SUCCESS) {
      keymgr_done = true;
    } else {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_rekey:dns_keymgr_offline "
           "failed: %s",
           isc_result_totext(result));
    }
  }

  KASP_UNLOCK(kasp);

  /*
   * Update CDS, CDNSKEY and DNSKEY record sets if the keymgr ran
   * successfully (dns_keymgr_run returned ISC_R_SUCCESS), or in
   * case of DNSSEC management without dnssec-policy if we have keys
   * (dns_dnssec_findmatchingkeys returned ISC_R_SUCCESS).
   */
  if (result == ISC_R_SUCCESS) {
    dns_kasp_digestlist_t digests;
    bool cdsdel = false;
    bool cdnskeydel = false;
    bool cdnskeypub = true;
    bool sane_diff, sane_dnskey;
    isc_stdtime_t when;

    result = dns_dnssec_updatekeys(&dnskeys, &keys, &rmkeys,
                 &zone->origin, ttl, &diff, mctx,
                 dnssec_report);
    /*
     * Keys couldn't be updated for some reason;
     * try again later.
     */
    if (result != ISC_R_SUCCESS) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_rekey:couldn't update zone keys: %s",
           isc_result_totext(result));
      goto cleanup;
    }

    if (offlineksk) {
      /* We can skip a lot of things */
      goto post_sync;
    }

    /*
     * Publish CDS/CDNSKEY DELETE records if the zone is
     * transitioning from secure to insecure.
     */
    if (kasp != NULL) {
      if (strcmp(dns_kasp_getname(kasp), "insecure") == 0) {
        cdsdel = true;
        cdnskeydel = true;
      }
      digests = dns_kasp_digests(kasp);
      cdnskeypub = dns_kasp_cdnskey(kasp);
    } else {
      /* Check if there is a CDS DELETE record. */
      if (dns_rdataset_isassociated(&cdsset)) {
        DNS_RDATASET_FOREACH(&cdsset) {
          dns_rdata_t crdata = DNS_RDATA_INIT;
          dns_rdataset_current(&cdsset, &crdata);
          /*
           * CDS deletion record has this form
           * "0 0 0 00" which is 5 zero octets.
           */
          if (crdata.length == 5U &&
              memcmp(crdata.data,
               (unsigned char[5]){ 0, 0, 0,
                       0, 0 },
               5) == 0)
          {
            cdsdel = true;
            break;
          }
        }
      }

      /* Check if there is a CDNSKEY DELETE record. */
      if (dns_rdataset_isassociated(&cdnskeyset)) {
        DNS_RDATASET_FOREACH(&cdnskeyset) {
          dns_rdata_t crdata = DNS_RDATA_INIT;
          dns_rdataset_current(&cdnskeyset,
                   &crdata);
          /*
           * CDNSKEY deletion record has this form
           * "0 3 0 AA==" which is 2 zero octets,
           * a 3, and 2 zero octets.
           */
          if (crdata.length == 5U &&
              memcmp(crdata.data,
               (unsigned char[5]){ 0, 0, 3,
                       0, 0 },
               5) == 0)
          {
            cdnskeydel = true;
            break;
          }
        }
      }

      digests = dns_kasp_digests(zone->defaultkasp);
    }

    /*
     * Update CDS / CDNSKEY records.
     */
    result = dns_dnssec_syncupdate(&dnskeys, &rmkeys, &cdsset,
                 &cdnskeyset, now, &digests,
                 cdnskeypub, ttl, &diff, mctx);
    if (result == ISC_R_SUCCESS) {
      notifycds = true;
    } else if (result != DNS_R_UNCHANGED) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_rekey:couldn't update CDS/CDNSKEY: %s",
           isc_result_totext(result));
      goto cleanup;
    }

    if (cdsdel || cdnskeydel) {
      /*
       * Only publish CDS/CDNSKEY DELETE records if there is
       * a KSK that can be used to verify the RRset. This
       * means there must be a key with the KSK role that is
       * published and is used for signing.
       */
      bool allow = false;
      ISC_LIST_FOREACH(dnskeys, key, link) {
        dst_key_t *dstk = key->key;

        if (dst_key_is_published(dstk, now, &when) &&
            dst_key_is_signing(dstk, DST_BOOL_KSK, now,
                   &when))
        {
          allow = true;
          break;
        }
      }
      if (cdsdel) {
        cdsdel = allow;
      }
      if (cdnskeydel) {
        cdnskeydel = allow;
      }
    }
    result = dns_dnssec_syncdelete(
      &cdsset, &cdnskeyset, &zone->origin, zone->rdclass, ttl,
      &diff, mctx, cdsdel, cdnskeydel);
    if (result == ISC_R_SUCCESS) {
      notifycds = true;
    } else if (result != DNS_R_UNCHANGED) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "zone_rekey:couldn't update CDS/CDNSKEY "
           "DELETE records: %s",
           isc_result_totext(result));
      goto cleanup;
    }

  post_sync:
    /*
     * See if any pre-existing keys have newly become active;
     * also, see if any new key is for a new algorithm, as in that
     * event, we need to sign the zone fully.  (If there's a new
     * key, but it's for an already-existing algorithm, then
     * the zone signing can be handled incrementally.)
     */
    ISC_LIST_FOREACH(dnskeys, key, link) {
      if (!key->first_sign) {
        continue;
      }

      newactive = true;

      if (!dns_rdataset_isassociated(&keysigs)) {
        newalg = true;
        break;
      }

      if (signed_with_alg(&keysigs, dst_key_alg(key->key))) {
        /*
         * This isn't a new algorithm; clear
         * first_sign so we won't sign the
         * whole zone with this key later.
         */
        key->first_sign = false;
      } else {
        newalg = true;
        break;
      }
    }

    /*
     * A sane diff is one that is not empty, and that does not
     * introduce a zone with NSEC only DNSKEYs along with NSEC3
     * chains.
     */
    sane_dnskey = dns_zone_check_dnskey_nsec3(zone, db, ver, &diff,
                NULL, 0);
    sane_diff = !ISC_LIST_EMPTY(diff.tuples) && sane_dnskey;
    if (!sane_dnskey) {
      dnssec_log(zone, ISC_LOG_ERROR,
           "NSEC only DNSKEYs and NSEC3 chains not "
           "allowed");
    }

    if (newactive || fullsign || sane_diff || kasp_change) {
      CHECK(dns_diff_apply(&diff, db, ver));
      CHECK(clean_nsec3param(zone, db, ver, &diff));
      CHECK(add_signing_records(db, zone->privatetype, ver,
              &diff, newalg || fullsign));
      CHECK(update_soa_serial(zone, db, ver, &diff, mctx,
            zone->updatemethod));
      CHECK(add_chains(zone, db, ver, &diff));
      CHECK(sign_apex(zone, db, ver, now, &diff, &zonediff));
      CHECK(zone_journal(zone, zonediff.diff, NULL,
             "zone_rekey"));
      commit = true;
    }
  }

  dns_db_closeversion(db, &ver, true);

  LOCK_ZONE(zone);

  if (commit) {
    dns_stats_t *dnssecsignstats =
      dns_zone_getdnssecsignstats(zone);

    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);

    zone_needdump(zone, DNS_DUMP_DELAY);

    dns__zone_settimer(zone, timenow);

    /* Remove any signatures from removed keys.  */
    ISC_LIST_FOREACH(rmkeys, key, link) {
      result = zone_signwithkey(zone, dst_key_alg(key->key),
              dst_key_id(key->key), true,
              false);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_signwithkey failed: "
             "%s",
             isc_result_totext(result));
      }

      /* Clear DNSSEC sign statistics. */
      if (dnssecsignstats != NULL) {
        dns_dnssecsignstats_clear(
          dnssecsignstats, dst_key_id(key->key),
          dst_key_alg(key->key));
        /*
         * Also clear the dnssec-sign
         * statistics of the revoked key id.
         */
        dns_dnssecsignstats_clear(
          dnssecsignstats, dst_key_rid(key->key),
          dst_key_alg(key->key));
      }
    }

    if (fullsign) {
      /*
       * "rndc sign" was called, so we now sign the zone
       * with all active keys, whether they're new or not.
       */
      ISC_LIST_FOREACH(dnskeys, key, link) {
        if (key->force_sign || key->hint_sign) {
          result = zone_signwithkey(
            zone, dst_key_alg(key->key),
            dst_key_id(key->key), false,
            true);
          if (result != ISC_R_SUCCESS) {
            dnssec_log(zone, ISC_LOG_ERROR,
                 "zone_signwithkey "
                 "failed: "
                 "%s",
                 isc_result_totext(
                   result));
          }
        }
      }
      /*
       * ...and remove signatures for all inactive keys.
       */
      ISC_LIST_FOREACH(dnskeys, key, link) {
        if (!key->force_sign && !key->hint_sign) {
          result = zone_signwithkey(
            zone, dst_key_alg(key->key),
            dst_key_id(key->key), true,
            false);
          if (result != ISC_R_SUCCESS) {
            dnssec_log(zone, ISC_LOG_ERROR,
                 "zone_signwithkey "
                 "failed: "
                 "%s",
                 isc_result_totext(
                   result));
          }
        }
      }

    } else if (newalg) {
      /*
       * We haven't been told to sign fully, but a new
       * algorithm was added to the DNSKEY.  We sign
       * the full zone, but only with newly active
       * keys.
       */
      ISC_LIST_FOREACH(dnskeys, key, link) {
        if (!key->first_sign) {
          continue;
        }

        result = zone_signwithkey(
          zone, dst_key_alg(key->key),
          dst_key_id(key->key), false, false);
        if (result != ISC_R_SUCCESS) {
          dnssec_log(zone, ISC_LOG_ERROR,
               "zone_signwithkey failed: "
               "%s",
               isc_result_totext(result));
        }
      }
    }

    /*
     * Clear fullsign flag, if it was set, so we don't do
     * another full signing next time.
     */
    DNS_ZONE_CLROPTION(zone, DNS_ZONEOPT_FULLSIGN);

    /*
     * Cause the zone to add/delete NSEC3 chains for the
     * deferred NSEC3PARAM changes.
     */
    ISC_LIST_FOREACH(zonediff.diff->tuples, tuple, link) {
      unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdata_nsec3param_t nsec3param;

      if (tuple->rdata.type != zone->privatetype ||
          tuple->op != DNS_DIFFOP_ADD)
      {
        continue;
      }

      if (!dns_nsec3param_fromprivate(&tuple->rdata, &rdata,
              buf, sizeof(buf)))
      {
        continue;
      }

      result = dns_rdata_tostruct(&rdata, &nsec3param);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);
      if (nsec3param.flags == 0) {
        continue;
      }

      result = zone_addnsec3chain(zone, &nsec3param);
      if (result != ISC_R_SUCCESS) {
        dnssec_log(zone, ISC_LOG_ERROR,
             "zone_addnsec3chain failed: %s",
             isc_result_totext(result));
      }
    }

    /*
     * Activate any NSEC3 chain updates that may have
     * been scheduled before this rekey.
     */
    if (fullsign || newalg) {
      resume_addnsec3chain(zone);
    }

    /*
     * Schedule the next resigning event
     */
    dns__zone_set_resigntime(zone);
  }

  isc_time_settoepoch(&zone->refreshkeytime);

  /*
   * If keymgr provided a next time, use the calculated next rekey time.
   */
  if (kasp != NULL) {
    isc_time_t timenext;
    uint32_t nexttime_seconds;

    /*
     * Set the key refresh timer to the next scheduled key event
     * or to 'dnssec-loadkeys-interval' seconds in the future
     * if no next key event is scheduled (nexttime == 0).
     */
    if (nexttime > 0) {
      nexttime_seconds = nexttime - now;
    } else {
      nexttime_seconds = zone->refreshkeyinterval;
    }

    DNS_ZONE_TIME_ADD(&timenow, nexttime_seconds, &timenext);
    zone->refreshkeytime = timenext;
    dns__zone_settimer(zone, timenow);
    isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);

    dnssec_log(zone, ISC_LOG_DEBUG(3),
         "next key event in %u seconds", nexttime_seconds);
    dnssec_log(zone, ISC_LOG_INFO, "next key event: %s", timebuf);
  } else {
    /*
     * If we're doing key maintenance, set the key refresh timer to
     * the next scheduled key event or to 'dnssec-loadkeys-interval'
     * seconds in the future, whichever is sooner.
     */
    isc_time_t timethen;
    isc_stdtime_t then;

    DNS_ZONE_TIME_ADD(&timenow, zone->refreshkeyinterval,
          &timethen);
    zone->refreshkeytime = timethen;

    ISC_LIST_FOREACH(dnskeys, key, link) {
      then = now;
      result = next_keyevent(key->key, &then);
      if (result != ISC_R_SUCCESS) {
        continue;
      }

      DNS_ZONE_TIME_ADD(&timenow, then - now, &timethen);
      if (isc_time_compare(&timethen, &zone->refreshkeytime) <
          0)
      {
        zone->refreshkeytime = timethen;
      }
    }

    dns__zone_settimer(zone, timenow);

    isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
    dnssec_log(zone, ISC_LOG_INFO, "next key event: %s", timebuf);
  }
  UNLOCK_ZONE(zone);

  /*
   * Remember which keys have been used.
   */
  if (!ISC_LIST_EMPTY(zone->keyring)) {
    clear_keylist(&zone->keyring, zone->mctx);
  }

  ISC_LIST_FOREACH(dnskeys, key, link) {
    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      /* This debug log is used in the kasp system test */
      char algbuf[DST_ALG_FORMATSIZE];
      dst_algorithm_format(dst_key_alg(key->key), algbuf,
               sizeof(algbuf));
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "zone_rekey done: key %hu/%s",
           dst_key_id(key->key), algbuf);
    }
    ISC_LIST_UNLINK(dnskeys, key, link);
    ISC_LIST_APPEND(zone->keyring, key, link);
  }

  if (keymgr_done && isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
    char namebuf[DNS_NAME_FORMATSIZE];

    dns_name_format(&zone->origin, namebuf, sizeof(namebuf));
    dnssec_log(zone, ISC_LOG_DEBUG(3), "keymgr: %s done", namebuf);
  }

  /*
   * If the CDS/CDNSKEY RRset has changed, send NOTIFY(CDS) to endpoints.
   */
  if (notifycds) {
    zone_notifycds(zone);
  }

  result = ISC_R_SUCCESS;

cleanup:
  LOCK_ZONE(zone);
  if (result != ISC_R_SUCCESS) {
    /*
     * Something went wrong; try again in ten minutes or
     * after a key refresh interval, whichever is shorter.
     */
    int loglevel = ISC_LOG_DEBUG(3);
    if (result != DNS_R_NOTLOADED) {
      loglevel = ISC_LOG_ERROR;
    }
    dnssec_log(zone, loglevel,
         "zone_rekey failure: %s (retry in %u seconds)",
         isc_result_totext(result),
         ISC_MIN(zone->refreshkeyinterval, 600));
    isc_interval_set(&ival, ISC_MIN(zone->refreshkeyinterval, 600),
         0);
    isc_time_nowplusinterval(&zone->refreshkeytime, &ival);
  }

  /*
   * Clear forcekeymgr flag, if it was set, so we don't do
   * another force next time.
   */
  DNS_ZONE_CLROPTION(zone, DNS_ZONEOPT_FORCEKEYMGR);

  UNLOCK_ZONE(zone);

  dns_diff_clear(&diff);
  dns_diff_clear(&_sig_diff);

  clear_keylist(&dnskeys, mctx);
  clear_keylist(&keys, mctx);
  clear_keylist(&rmkeys, mctx);

  if (ver != NULL) {
    dns_db_closeversion(db, &ver, false);
  }
  dns_rdataset_cleanup(&cdsset);
  dns_rdataset_cleanup(&keyset);
  dns_rdataset_cleanup(&keysigs);
  dns_rdataset_cleanup(&soasigs);
  dns_rdataset_cleanup(&cdnskeyset);
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }

  INSIST(ver == NULL);
}

void
dns_zone_rekey(dns_zone_t *zone, bool fullsign, bool forcekeymgr) {
  isc_time_t now;

  if (zone->type == dns_zone_primary && zone->loop != NULL) {
    LOCK_ZONE(zone);

    if (fullsign) {
      DNS_ZONE_SETOPTION(zone, DNS_ZONEOPT_FULLSIGN);
    }
    if (forcekeymgr) {
      DNS_ZONE_SETOPTION(zone, DNS_ZONEOPT_FORCEKEYMGR);
    }

    now = isc_time_now();
    zone->refreshkeytime = now;
    dns__zone_settimer(zone, now);

    UNLOCK_ZONE(zone);
  }
}

isc_result_t
dns_zone_dnssecstatus(dns_zone_t *zone, dns_kasp_t *kasp,
          dns_dnsseckeylist_t *keys, isc_stdtime_t now,
          bool verbose, char *out, size_t out_len) {
  isc_result_t result;
  isc_buffer_t buf;
  isc_time_t refreshkeytime;
  isc_stdtime_t refresh;
  char timestr[26];
  char namebuf[DNS_NAME_FORMATSIZE];

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(out != NULL);

  dns_zone_nameonly(zone, namebuf, sizeof(namebuf));
  isc_buffer_init(&buf, out, out_len);

  RETERR(isc_buffer_printf(
    &buf, "DNSSEC status for zone '%s' using policy '%s':\n",
    namebuf, dns_kasp_getname(kasp)));

  isc_stdtime_tostring(now, timestr, sizeof(timestr));
  RETERR(isc_buffer_printf(&buf, "Current time:   %s\n", timestr));

  dns_zone_getrefreshkeytime(zone, &refreshkeytime);
  refresh = isc_time_seconds(&refreshkeytime);
  isc_stdtime_tostring(refresh, timestr, sizeof(timestr));
  RETERR(isc_buffer_printf(&buf, "Next key event: %s\n", timestr));

  bool checkds = zone->checkdstype != dns_checkdstype_no;
  LOCK(&kasp->lock);
  result = dns_keymgr_status(kasp, keys, &buf, now, verbose, checkds);
  UNLOCK(&kasp->lock);

  return result;
}

isc_result_t
dns_zone_nscheck(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version,
     unsigned int *errors) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(errors != NULL);

  RETERR(dns_db_getoriginnode(db, &node));
  result = zone_count_ns_rr(zone, db, node, version, NULL, errors, false);
  dns_db_detachnode(&node);
  return result;
}

isc_result_t
dns_zone_cdscheck(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t dnskey, cds, cdnskey;
  unsigned char algorithms[DST_MAX_ALGS];
  unsigned int i;
  bool empty = false;

  enum { notexpected = 0, expected = 1, found = 2 };

  REQUIRE(DNS_ZONE_VALID(zone));

  RETERR(dns_db_getoriginnode(db, &node));

  dns_rdataset_init(&cds);
  dns_rdataset_init(&dnskey);
  dns_rdataset_init(&cdnskey);

  result = dns_db_findrdataset(db, node, version, dns_rdatatype_cds,
             dns_rdatatype_none, 0, &cds, NULL);
  if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  result = dns_db_findrdataset(db, node, version, dns_rdatatype_cdnskey,
             dns_rdatatype_none, 0, &cdnskey, NULL);
  if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  if (!dns_rdataset_isassociated(&cds) &&
      !dns_rdataset_isassociated(&cdnskey))
  {
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  result = dns_db_findrdataset(db, node, version, dns_rdatatype_dnskey,
             dns_rdatatype_none, 0, &dnskey, NULL);
  if (result == ISC_R_NOTFOUND) {
    empty = true;
  } else {
    CHECK(result);
  }

  /*
   * For each DNSSEC algorithm in the CDS RRset there must be
   * a matching DNSKEY record with the exception of a CDS deletion
   * record which must be by itself.
   */
  if (dns_rdataset_isassociated(&cds)) {
    bool logged_digest_type[DNS_DSDIGEST_MAX + 1] = { 0 };
    bool delete = false;
    memset(algorithms, notexpected, sizeof(algorithms));
    DNS_RDATASET_FOREACH(&cds) {
      dns_rdata_t crdata = DNS_RDATA_INIT;
      dns_rdata_cds_t structcds;

      dns_rdataset_current(&cds, &crdata);
      /*
       * CDS deletion record has this form "0 0 0 00" which
       * is 5 zero octets.
       */
      if (crdata.length == 5U &&
          memcmp(crdata.data,
           (unsigned char[5]){ 0, 0, 0, 0, 0 }, 5) == 0)
      {
        delete = true;
        continue;
      }

      if (empty) {
        CLEANUP(DNS_R_BADCDS);
      }

      CHECK(dns_rdata_tostruct(&crdata, &structcds));

      /*
       * Log deprecated CDS digest types.
       */
      switch (structcds.digest_type) {
      case DNS_DSDIGEST_SHA1:
      case DNS_DSDIGEST_GOST:
        if (!logged_digest_type[structcds.digest_type])
        {
          char algbuf[DNS_DSDIGEST_FORMATSIZE];
          dns_dsdigest_format(
            structcds.digest_type, algbuf,
            sizeof(algbuf));
          dnssec_log(zone, ISC_LOG_WARNING,
               "deprecated CDS digest type "
               "%u (%s)",
               structcds.digest_type,
               algbuf);
          logged_digest_type[structcds.digest_type] =
            true;
        }
        break;
      }

      if (structcds.algorithm != DNS_KEYALG_PRIVATEDNS &&
          structcds.algorithm != DNS_KEYALG_PRIVATEOID)
      {
        if (algorithms[structcds.algorithm] == 0) {
          algorithms[structcds.algorithm] =
            expected;
        }
        DNS_RDATASET_FOREACH(&dnskey) {
          dns_rdata_t rdata = DNS_RDATA_INIT;
          dns_rdata_dnskey_t structdnskey;

          dns_rdataset_current(&dnskey, &rdata);
          dns_rdata_tostruct(&rdata,
                 &structdnskey);

          if (structdnskey.algorithm ==
              structcds.algorithm)
          {
            algorithms[structcds.algorithm] =
              found;
          }
        }
      } else {
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_dnskey_t structdnskey;
        dst_algorithm_t dnskeyalg;

        /* Convert CDS to DS */
        crdata.type = dns_rdatatype_ds;
        result = dns_dnssec_matchdskey(&zone->origin,
                     &crdata, &dnskey,
                     &rdata);
        if (result != ISC_R_SUCCESS) {
          CLEANUP(DNS_R_BADCDS);
        }
        CHECK(dns_rdata_tostruct(&rdata,
               &structdnskey));
        dnskeyalg = dst_algorithm_fromdata(
          structdnskey.algorithm,
          structdnskey.data,
          structdnskey.datalen);
        algorithms[dnskeyalg] = found;
      }
    }
    for (i = 0; i < sizeof(algorithms); i++) {
      if (delete) {
        if (algorithms[i] != notexpected) {
          CLEANUP(DNS_R_BADCDS);
        }
      } else if (algorithms[i] == expected) {
        CLEANUP(DNS_R_BADCDS);
      }
    }
  }

  /*
   * For each DNSSEC algorithm in the CDNSKEY RRset there must be
   * a matching DNSKEY record with the exception of a CDNSKEY deletion
   * record which must be by itself.
   */
  if (dns_rdataset_isassociated(&cdnskey)) {
    bool delete = false;
    memset(algorithms, notexpected, sizeof(algorithms));
    DNS_RDATASET_FOREACH(&cdnskey) {
      dns_rdata_t crdata = DNS_RDATA_INIT;
      dns_rdata_cdnskey_t structcdnskey;
      dst_algorithm_t cdnskeyalg;

      dns_rdataset_current(&cdnskey, &crdata);
      /*
       * CDNSKEY deletion record has this form
       * "0 3 0 AA==" which is 2 zero octets, a 3,
       * and 2 zero octets.
       */
      if (crdata.length == 5U &&
          memcmp(crdata.data,
           (unsigned char[5]){ 0, 0, 3, 0, 0 }, 5) == 0)
      {
        delete = true;
        continue;
      }

      if (empty) {
        CLEANUP(DNS_R_BADCDNSKEY);
      }

      CHECK(dns_rdata_tostruct(&crdata, &structcdnskey));
      cdnskeyalg = dst_algorithm_fromdata(
        structcdnskey.algorithm, structcdnskey.data,
        structcdnskey.datalen);
      if (algorithms[cdnskeyalg] == 0) {
        algorithms[cdnskeyalg] = expected;
      }
      DNS_RDATASET_FOREACH(&dnskey) {
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_dnskey_t structdnskey;
        dst_algorithm_t dnskeyalg;

        dns_rdataset_current(&dnskey, &rdata);
        CHECK(dns_rdata_tostruct(&rdata,
               &structdnskey));
        dnskeyalg = dst_algorithm_fromdata(
          structdnskey.algorithm,
          structdnskey.data,
          structdnskey.datalen);

        if (dnskeyalg == cdnskeyalg) {
          algorithms[cdnskeyalg] = found;
        }
      }
    }
    for (i = 0; i < sizeof(algorithms); i++) {
      if (delete) {
        if (algorithms[i] != notexpected) {
          CLEANUP(DNS_R_BADCDNSKEY);
        }
      } else if (algorithms[i] == expected) {
        CLEANUP(DNS_R_BADCDNSKEY);
      }
    }
  }
  result = ISC_R_SUCCESS;

cleanup:
  dns_rdataset_cleanup(&cds);
  dns_rdataset_cleanup(&dnskey);
  dns_rdataset_cleanup(&cdnskey);
  dns_db_detachnode(&node);
  return result;
}

isc_result_t
dns_zone_dlzpostload(dns_zone_t *zone, dns_db_t *db) {
  isc_time_t loadtime;
  isc_result_t result;
  dns_zone_t *secure = NULL;

  loadtime = isc_time_now();

  /*
   * Lock hierarchy: zmgr, zone, secure.
   */
again:
  LOCK_ZONE(zone);
  INSIST(zone != zone->raw);
  if (dns__zone_inline_raw(zone)) {
    secure = zone->secure;
    TRYLOCK_ZONE(result, secure);
    if (result != ISC_R_SUCCESS) {
      UNLOCK_ZONE(zone);
      secure = NULL;
      isc_thread_yield();
      goto again;
    }
  }
  result = zone_postload(zone, db, loadtime, ISC_R_SUCCESS);
  if (result == ISC_R_SUCCESS && dns__zone_inline_secure(zone)) {
    zone_schedule_inline_sync(zone, inline_sync_incremental);
  }
  if (secure != NULL) {
    UNLOCK_ZONE(secure);
  }
  UNLOCK_ZONE(zone);
  return result;
}

/*
 * Link a fresh raw zone to its signed counterpart on the same event loop.
 */
isc_result_t
dns_zone_link(dns_zone_t *zone, dns_zone_t *raw) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(zone->loop != NULL);
  REQUIRE(zone->raw == NULL);

  REQUIRE(DNS_ZONE_VALID(raw));
  REQUIRE(raw->secure == NULL);

  REQUIRE(zone != raw);

  /*
   * Lock hierarchy: zone, raw. No global registration is needed.
   */
  LOCK_ZONE(zone);
  LOCK_ZONE(raw);

  REQUIRE(raw->timer == NULL);
  if (raw->loop != NULL) {
    isc_loop_detach(&raw->loop);
  }
  raw->tid = zone->tid;
  isc_loop_attach(zone->loop, &raw->loop);

  /* dns_zone_attach(raw, &zone->raw); */
  isc_refcount_increment(&raw->references);
  zone->raw = raw;

  /* dns_zone_iattach(zone, &raw->secure); */
  zone_iattach(zone, &raw->secure);

  UNLOCK_ZONE(raw);
  UNLOCK_ZONE(zone);
  return ISC_R_SUCCESS;
}

void
dns_zone_getraw(dns_zone_t *zone, dns_zone_t **raw) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(raw != NULL && *raw == NULL);

  LOCK(&zone->lock);
  INSIST(zone != zone->raw);
  if (zone->raw != NULL) {
    dns_zone_attach(zone->raw, raw);
  }
  UNLOCK(&zone->lock);
}

bool
dns_zone_israw(dns_zone_t *zone) {
  bool israw;
  REQUIRE(DNS_ZONE_VALID(zone));
  LOCK(&zone->lock);
  israw = zone->secure != NULL;
  UNLOCK(&zone->lock);
  return israw;
}

bool
dns_zone_issecure(dns_zone_t *zone) {
  bool issecure;
  REQUIRE(DNS_ZONE_VALID(zone));
  LOCK(&zone->lock);
  issecure = zone->raw != NULL;
  UNLOCK(&zone->lock);
  return issecure;
}

#define PENDINGFLAGS (DNS_NSEC3FLAG_CREATE | DNS_NSEC3FLAG_INITIAL)

static void
zone_process_keydone(dns_zone_t *zone,
         const zone_maintenance_request_t *request) {
  bool commit = false;
  isc_result_t result;
  dns_dbversion_t *oldver = NULL, *newver = NULL;
  dns_db_t *db = NULL;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset;
  dns_diff_t diff;
  dns_update_log_t log = { update_log_cb, NULL };
  bool clear_pending = false;

  INSIST(DNS_ZONE_VALID(zone));

  ENTER;

  dns_rdataset_init(&rdataset);
  dns_diff_init(zone->mctx, &diff);

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    goto cleanup;
  }

  dns_db_currentversion(db, &oldver);
  result = dns_db_newversion(db, &newver);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "keydone:dns_db_newversion -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  CHECK(dns_db_getoriginnode(db, &node));

  result = dns_db_findrdataset(db, node, newver, zone->privatetype,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    bool found = false;

    dns_rdataset_current(&rdataset, &rdata);

    if (request->u.keydone.all) {
      /* Old (5) and new (7) forms */
      if ((rdata.length == OLD_SIGNING_RECORD_SIZE ||
           rdata.length == SIGNING_RECORD_SIZE) &&
          rdata.data[0] != 0 && rdata.data[3] == 0 &&
          rdata.data[4] == 1)
      {
        found = true;
      } else if (rdata.data[0] == 0 &&
           (rdata.data[2] & PENDINGFLAGS) != 0)
      {
        found = true;
        clear_pending = true;
      }
    } else if (rdata.length == OLD_SIGNING_RECORD_SIZE &&
         memcmp(rdata.data, request->u.keydone.data,
          OLD_SIGNING_RECORD_SIZE) == 0)
    {
      found = true;
    } else if (rdata.length == SIGNING_RECORD_SIZE &&
         memcmp(rdata.data, request->u.keydone.data,
          SIGNING_RECORD_SIZE) == 0)
    {
      found = true;
    }

    if (found) {
      CHECK(update_one_rr(db, newver, &diff, DNS_DIFFOP_DEL,
              &zone->origin, rdataset.ttl,
              &rdata));
    }
  }

  if (!ISC_LIST_EMPTY(diff.tuples)) {
    /* Write changes to journal file. */
    CHECK(update_soa_serial(zone, db, newver, &diff, zone->mctx,
          zone->updatemethod));

    result = dns_update_signatures(&log, zone, db, oldver, newver,
                 &diff,
                 zone->sigvalidityinterval);
    if (!clear_pending) {
      CHECK(result);
    }

    CHECK(zone_journal(zone, &diff, NULL, "keydone"));
    commit = true;

    LOCK_ZONE(zone);
    DNS_ZONE_SETFLAG(zone,
         DNS_ZONEFLG_LOADED | DNS_ZONEFLG_NEEDNOTIFY);
    zone_needdump(zone, 30);
    UNLOCK_ZONE(zone);
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  if (db != NULL) {
    if (node != NULL) {
      dns_db_detachnode(&node);
    }
    if (oldver != NULL) {
      dns_db_closeversion(db, &oldver, false);
    }
    if (newver != NULL) {
      dns_db_closeversion(db, &newver, commit);
    }
    dns_db_detach(&db);
  }
  dns_diff_clear(&diff);

  INSIST(oldver == NULL);
  INSIST(newver == NULL);
}

isc_result_t
dns_zone_keydone(dns_zone_t *zone, const char *keystr) {
  isc_result_t result = ISC_R_SUCCESS;
  zone_maintenance_request_t *request = NULL;
  isc_buffer_t b;
  bool all = false;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);

  all = strcasecmp(keystr, "all") == 0;
  request = isc_mem_get(zone->mctx, sizeof(*request));
  *request = (zone_maintenance_request_t){
    .link = ISC_LINK_INITIALIZER,
    .type = zone_maintenance_request_keydone,
    .u.keydone = {
      .all = all,
    },
  };

  if (!all) {
    isc_textregion_t r;
    const char *algstr = NULL;
    dns_keytag_t keyid;
    dst_algorithm_t alg;
    size_t n;

    n = sscanf(keystr, "%hu/", &keyid);
    if (n == 0U) {
      CLEANUP(ISC_R_FAILURE);
    }

    algstr = strchr(keystr, '/');
    if (algstr != NULL) {
      algstr++;
    } else {
      CLEANUP(ISC_R_FAILURE);
    }

    n = sscanf(algstr, "%u", &alg);
    if (n == 0U) {
      r.base = UNCONST(algstr);
      r.length = strlen(algstr);
      CHECK(dst_algorithm_fromtext(&alg, &r));
    }

    /* construct a private-type rdata */
    isc_buffer_init(&b, request->u.keydone.data,
        sizeof(request->u.keydone.data));
    isc_buffer_putuint8(&b, dst_algorithm_tosecalg(alg));
    isc_buffer_putuint16(&b, keyid);
    isc_buffer_putuint8(&b, 0);
    isc_buffer_putuint8(&b, 1);
    isc_buffer_putuint16(&b, alg);
  }

  ISC_LIST_APPEND(zone->maintenance_queue, request, link);
  if (zone->loop != NULL && zone_maintenance_request_pending(zone)) {
    isc_time_t now = isc_time_now();
    dns__zone_settimer(zone, now);
  }
  request = NULL;

cleanup:
  if (request != NULL) {
    isc_mem_put(zone->mctx, request, sizeof(*request));
  }
  UNLOCK_ZONE(zone);
  return result;
}

static void
salt2text(unsigned char *salt, uint8_t saltlen, unsigned char *text,
    unsigned int textlen) {
  isc_region_t r;
  isc_buffer_t buf;
  isc_result_t result;

  r.base = salt;
  r.length = (unsigned int)saltlen;

  isc_buffer_init(&buf, text, textlen);
  result = isc_hex_totext(&r, 2, "", &buf);
  if (result == ISC_R_SUCCESS) {
    text[saltlen * 2] = 0;
  } else {
    text[0] = 0;
  }
}

/*
 * Check whether NSEC3 chain addition or removal specified by the private-type
 * record passed with the event was already queued (or even fully performed).
 * If not, modify the relevant private-type records at the zone apex and call
 * resume_addnsec3chain().
 */
static void
rss_post(dns_zone_t *zone, nsec3param_t *np) {
  bool commit = false;
  isc_result_t result;
  dns_dbversion_t *oldver = NULL, *newver = NULL;
  dns_db_t *db = NULL;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t prdataset, nrdataset;
  dns_diff_t diff;
  dns_update_log_t log = { update_log_cb, NULL };
  bool nseconly;
  bool exists = false;

  ENTER;

  dns_rdataset_init(&prdataset);
  dns_rdataset_init(&nrdataset);
  dns_diff_init(zone->mctx, &diff);

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    goto cleanup;
  }

  dns_db_currentversion(db, &oldver);
  result = dns_db_newversion(db, &newver);
  if (result != ISC_R_SUCCESS) {
    dnssec_log(zone, ISC_LOG_ERROR,
         "setnsec3param:dns_db_newversion -> %s",
         isc_result_totext(result));
    goto cleanup;
  }

  CHECK(dns_db_getoriginnode(db, &node));

  /*
   * Do we need to look up the NSEC3 parameters?
   */
  if (np->lookup) {
    dns_rdata_nsec3param_t param;
    dns_rdata_t nrdata = DNS_RDATA_INIT;
    dns_rdata_t prdata = DNS_RDATA_INIT;
    unsigned char nbuf[DNS_NSEC3PARAM_BUFFERSIZE];
    unsigned char saltbuf[255];
    isc_buffer_t b;

    param.salt = (isc_region_t){ .base = NULL };
    result = dns__zone_lookup_nsec3param(zone, &np->rdata, &param,
                 saltbuf, np->resalt);
    if (result == ISC_R_SUCCESS) {
      /*
       * Success because the NSEC3PARAM already exists, but
       * function returns void, so goto cleanup.
       */
      goto cleanup;
    }
    if (result != DNS_R_NSEC3RESALT && result != ISC_R_NOTFOUND) {
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "setnsec3param:lookup nsec3param -> %s",
           isc_result_totext(result));
      goto cleanup;
    }

    INSIST(param.salt.base != NULL);

    /* Update NSEC3 parameters. */
    np->rdata.hash = param.hash;
    np->rdata.flags = param.flags;
    np->rdata.iterations = param.iterations;
    np->rdata.salt.length = param.salt.length;
    np->rdata.salt = param.salt;

    isc_buffer_init(&b, nbuf, sizeof(nbuf));
    CHECK(dns_rdata_fromstruct(&nrdata, zone->rdclass,
             dns_rdatatype_nsec3param, &np->rdata,
             &b));
    dns_nsec3param_toprivate(&nrdata, &prdata, zone->privatetype,
           np->data, sizeof(np->data));
    np->length = prdata.length;
    np->nsec = false;
  }

  /*
   * Does a private-type record already exist for this chain?
   */
  result = dns_db_findrdataset(db, node, newver, zone->privatetype,
             dns_rdatatype_none, 0, &prdataset, NULL);
  if (result == ISC_R_SUCCESS) {
    DNS_RDATASET_FOREACH(&prdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&prdataset, &rdata);

      if (np->length == rdata.length &&
          memcmp(rdata.data, np->data, np->length) == 0)
      {
        exists = true;
        break;
      }
    }
  } else if (result != ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&prdataset));
    goto cleanup;
  }

  /*
   * Does the chain already exist?
   */
  result = dns_db_findrdataset(db, node, newver, dns_rdatatype_nsec3param,
             dns_rdatatype_none, 0, &nrdataset, NULL);
  if (result == ISC_R_SUCCESS) {
    DNS_RDATASET_FOREACH(&nrdataset) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      dns_rdataset_current(&nrdataset, &rdata);

      if (np->length == ((unsigned int)rdata.length + 1) &&
          memcmp(rdata.data, np->data + 1, np->length - 1) ==
            0)
      {
        exists = true;
        break;
      }
    }
  } else if (result != ISC_R_NOTFOUND) {
    INSIST(!dns_rdataset_isassociated(&nrdataset));
    goto cleanup;
  }

  /*
   * We need to remove any existing NSEC3 chains if the supplied NSEC3
   * parameters are supposed to replace the current ones or if we are
   * switching to NSEC.
   */
  if (!exists && np->replace && (np->length != 0 || np->nsec)) {
    CHECK(dns_nsec3param_deletechains(db, newver, zone, !np->nsec,
              &diff));
  }

  if (!exists && np->length != 0) {
    /*
     * We're creating an NSEC3 chain.  Add the private-type record
     * passed in the request parameters to the zone apex.
     *
     * If the zone is not currently capable of supporting an NSEC3
     * chain (due to the DNSKEY RRset at the zone apex not existing
     * or containing at least one key using an NSEC-only
     * algorithm), add the INITIAL flag, so these parameters can be
     * used later when NSEC3 becomes available.
     */
    dns_rdata_t rdata = DNS_RDATA_INIT;

    np->data[2] |= DNS_NSEC3FLAG_CREATE;
    result = dns_nsec_nseconly(db, newver, NULL, &nseconly);
    if (result == ISC_R_NOTFOUND || nseconly) {
      np->data[2] |= DNS_NSEC3FLAG_INITIAL;
    }

    rdata.length = np->length;
    rdata.data = np->data;
    rdata.type = zone->privatetype;
    rdata.rdclass = zone->rdclass;
    CHECK(update_one_rr(db, newver, &diff, DNS_DIFFOP_ADD,
            &zone->origin, 0, &rdata));
  }

  /*
   * If we changed anything in the zone, write changes to journal file
   * and set commit to true so that resume_addnsec3chain() will be
   * called below in order to kick off adding/removing relevant NSEC3
   * records.
   */
  if (!ISC_LIST_EMPTY(diff.tuples)) {
    CHECK(update_soa_serial(zone, db, newver, &diff, zone->mctx,
          zone->updatemethod));
    result = dns_update_signatures(&log, zone, db, oldver, newver,
                 &diff,
                 zone->sigvalidityinterval);
    if (result != ISC_R_NOTFOUND) {
      CHECK(result);
    }
    CHECK(zone_journal(zone, &diff, NULL, "setnsec3param"));
    commit = true;
  }

cleanup:
  dns_rdataset_cleanup(&prdataset);
  dns_rdataset_cleanup(&nrdataset);
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (oldver != NULL) {
    dns_db_closeversion(db, &oldver, false);
  }
  if (newver != NULL) {
    dns_db_closeversion(db, &newver, commit);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }
  if (commit) {
    LOCK_ZONE(zone);
    DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
    zone_needdump(zone, 30);
    resume_addnsec3chain(zone);
    UNLOCK_ZONE(zone);
  }
  dns_diff_clear(&diff);

  INSIST(oldver == NULL);
  INSIST(newver == NULL);
}

/*
 * Check if zone has NSEC3PARAM (and thus a chain) with the right parameters.
 *
 * If 'salt' is NULL, a match is found if the salt has the requested length,
 * otherwise the NSEC3 salt must match the requested salt value too.
 *
 * Returns  ISC_R_SUCCESS, if a match is found, or an error if no match is
 * found, or if the db lookup failed.
 */
isc_result_t
dns__zone_lookup_nsec3param(dns_zone_t *zone, dns_rdata_nsec3param_t *lookup,
          dns_rdata_nsec3param_t *param,
          unsigned char saltbuf[255], bool resalt) {
  isc_result_t result = ISC_R_UNEXPECTED;
  dns_dbnode_t *node = NULL;
  dns_db_t *db = NULL;
  dns_dbversion_t *version = NULL;
  dns_rdataset_t rdataset;
  dns_rdata_nsec3param_t nsec3param;

  REQUIRE(DNS_ZONE_VALID(zone));

  dns_rdataset_init(&rdataset);

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    result = ISC_R_FAILURE;
    goto setparam;
  }

  result = dns_db_findnode(db, &zone->origin, false, &node);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "dns__zone_lookup_nsec3param:"
           "dns_db_findnode -> %s",
           isc_result_totext(result));
    result = ISC_R_FAILURE;
    goto setparam;
  }
  dns_db_currentversion(db, &version);

  result = dns_db_findrdataset(db, node, version,
             dns_rdatatype_nsec3param,
             dns_rdatatype_none, 0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    INSIST(!dns_rdataset_isassociated(&rdataset));
    if (result != ISC_R_NOTFOUND) {
      dns_zone_log(zone, ISC_LOG_ERROR,
             "dns__zone_lookup_nsec3param:"
             "dns_db_findrdataset -> %s",
             isc_result_totext(result));
    }
    goto setparam;
  }

  result = ISC_R_NOTFOUND;
  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &rdata);
    dns_rdata_tostruct(&rdata, &nsec3param);

    /* Check parameters. */
    if (nsec3param.hash != lookup->hash) {
      continue;
    }
    if (nsec3param.iterations != lookup->iterations) {
      continue;
    }
    if (nsec3param.salt.length != lookup->salt.length) {
      continue;
    }
    if (lookup->salt.base != NULL) {
      if (memcmp(nsec3param.salt.base, lookup->salt.base,
           lookup->salt.length) != 0)
      {
        continue;
      }
    }
    /* Found a match. */
    result = ISC_R_SUCCESS;
    param->hash = nsec3param.hash;
    param->flags = nsec3param.flags;
    param->iterations = nsec3param.iterations;
    param->salt = nsec3param.salt;
    break;
  }

setparam:
  if (result != ISC_R_SUCCESS) {
    /* Found no match. */
    param->hash = lookup->hash;
    param->flags = lookup->flags;
    param->iterations = lookup->iterations;
    param->salt = lookup->salt;
  }

  if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  if (param->salt.length == 0) {
    param->salt.base = (unsigned char *)"-";
  } else if (resalt || param->salt.base == NULL) {
    unsigned char *newsalt;
    unsigned char salttext[255 * 2 + 1];
    do {
      /* Generate a new salt. */
      result = dns_nsec3_generate_salt(saltbuf,
               param->salt.length);
      if (result != ISC_R_SUCCESS) {
        break;
      }
      newsalt = saltbuf;
      salt2text(newsalt, param->salt.length, salttext,
          sizeof(salttext));
      dnssec_log(zone, ISC_LOG_INFO, "generated salt: %s",
           salttext);
      /* Check for salt conflict. */
      if (param->salt.base != NULL &&
          memcmp(newsalt, param->salt.base,
           param->salt.length) == 0)
      {
        result = ISC_R_SUCCESS;
      } else {
        param->salt.base = newsalt;
        result = DNS_R_NSEC3RESALT;
      }
    } while (result == ISC_R_SUCCESS);

    INSIST(result != ISC_R_SUCCESS);
  }

cleanup:
  dns_rdataset_cleanup(&rdataset);
  if (node != NULL) {
    dns_db_detachnode(&node);
  }
  if (version != NULL) {
    dns_db_closeversion(db, &version, false);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }

  return result;
}

/*
 * Called when an "rndc signing -nsec3param ..." command is received, or the
 * 'dnssec-policy' has changed.
 *
 * Allocate and prepare an nsec3param_t structure which holds information about
 * the NSEC3 changes requested for the zone:
 *
 *   - if NSEC3 is to be disabled ("-nsec3param none"), only set the "nsec"
 *     field of the structure to true and the "replace" field to the value
 *     of the "replace" argument, leaving other fields initialized to zeros, to
 *     signal that the zone should be signed using NSEC instead of NSEC3,
 *
 *   - otherwise, prepare NSEC3PARAM RDATA that will eventually be inserted at
 *     the zone apex, convert it to a private-type record and store the latter
 *     in the "data" field of the nsec3param_t structure.
 *
 * Once the nsec3param_t structure is prepared, queue it for zone maintenance.
 * The request is processed once the zone DB is loaded and no inline-signing
 * transaction is active.
 */
isc_result_t
dns_zone_setnsec3param(dns_zone_t *zone, uint8_t hash, uint8_t flags,
           uint16_t iter, isc_region_t *salt, bool replace,
           bool resalt) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_rdata_nsec3param_t param, lookup;
  dns_rdata_t nrdata = DNS_RDATA_INIT;
  dns_rdata_t prdata = DNS_RDATA_INIT;
  unsigned char nbuf[DNS_NSEC3PARAM_BUFFERSIZE];
  unsigned char saltbuf[255];
  zone_maintenance_request_t *request = NULL;
  nsec3param_t *np = NULL;
  isc_buffer_t b;
  bool do_lookup = false;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);

  /*
   * First check if the requested NSEC3 parameters are already
   * set, if so, no need to set again.
   */
  if (hash != 0) {
    lookup.hash = hash;
    lookup.flags = flags;
    lookup.iterations = iter;
    lookup.salt = *salt;
    param.salt = (isc_region_t){ .base = NULL };
    result = dns__zone_lookup_nsec3param(zone, &lookup, &param,
                 saltbuf, resalt);
    if (result == ISC_R_SUCCESS) {
      UNLOCK_ZONE(zone);
      return ISC_R_SUCCESS;
    }
    /*
     * Schedule lookup if lookup above failed (may happen if
     * zone db is NULL for example).
     */
    do_lookup = (param.salt.base == NULL) ? true : false;
  }

  request = isc_mem_get(zone->mctx, sizeof(*request));
  *request = (zone_maintenance_request_t){
    .link = ISC_LINK_INITIALIZER,
    .type = zone_maintenance_request_setnsec3param,
    .u.nsec3param = {
      .replace = replace,
      .resalt = resalt,
      .lookup = do_lookup,
    },
  };

  np = &request->u.nsec3param;
  if (hash == 0) {
    np->nsec = true;
    dnssec_log(zone, ISC_LOG_DEBUG(3), "setnsec3param:nsec");
  } else {
    param.common.rdclass = zone->rdclass;
    param.common.rdtype = dns_rdatatype_nsec3param;
    /*
     * nsec3 specific param set in
     * dns__zone_lookup_nsec3param()
     */
    isc_buffer_init(&b, nbuf, sizeof(nbuf));

    if (param.salt.base != NULL) {
      CHECK(dns_rdata_fromstruct(&nrdata, zone->rdclass,
               dns_rdatatype_nsec3param,
               &param, &b));
      dns_nsec3param_toprivate(&nrdata, &prdata,
             zone->privatetype, np->data,
             sizeof(np->data));
      np->length = prdata.length;
    }

    np->rdata = param;

    if (isc_log_wouldlog(ISC_LOG_DEBUG(3))) {
      unsigned char salttext[255 * 2 + 1];
      if (param.salt.base != NULL) {
        salt2text(param.salt.base, param.salt.length,
            salttext, sizeof(salttext));
      }
      dnssec_log(zone, ISC_LOG_DEBUG(3),
           "setnsec3param:nsec3 %u %u %u %u:%s",
           param.hash, param.flags, param.iterations,
           param.salt.length,
           param.salt.base == NULL ? "unknown"
                 : (char *)salttext);
    }
  }

  /*
   * Queue the request and let zone maintenance process it once the zone
   * DB is loaded and no inline-signing transaction is active.
   */
  ISC_LIST_APPEND(zone->maintenance_queue, request, link);
  if (zone->loop != NULL && zone_maintenance_request_pending(zone)) {
    isc_time_t now = isc_time_now();
    dns__zone_settimer(zone, now);
  }
  request = NULL;

  result = ISC_R_SUCCESS;

cleanup:
  if (request != NULL) {
    isc_mem_put(zone->mctx, request, sizeof(*request));
  }
  UNLOCK_ZONE(zone);
  return result;
}

unsigned int
dns_zone_getincludes(dns_zone_t *zone, char ***includesp) {
  char **array = NULL;
  unsigned int n = 0, count = 0;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(includesp != NULL && *includesp == NULL);

  LOCK_ZONE(zone);
  ISC_LIST_FOREACH(zone->includes, include, link) {
    count++;
  }
  if (count == 0) {
    goto done;
  }

  array = isc_mem_allocate(zone->mctx, sizeof(char *) * count);
  ISC_LIST_FOREACH(zone->includes, include, link) {
    INSIST(n < count);
    array[n++] = isc_mem_strdup(zone->mctx, include->name);
  }
  INSIST(n == count);
  *includesp = array;

done:
  UNLOCK_ZONE(zone);
  return n;
}

static void
zone_process_setserial(dns_zone_t *zone,
           const zone_maintenance_request_t *request) {
  uint32_t oldserial, desired;
  bool commit = false;
  isc_result_t result;
  dns_dbversion_t *oldver = NULL, *newver = NULL;
  dns_db_t *db = NULL;
  dns_diff_t diff;
  dns_update_log_t log = { update_log_cb, NULL };
  dns_difftuple_t *oldtuple = NULL, *newtuple = NULL;

  INSIST(DNS_ZONE_VALID(zone));

  ENTER;

  if (zone->update_disabled) {
    goto disabled;
  }

  desired = request->u.setserial.serial;

  dns_diff_init(zone->mctx, &diff);

  ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
  if (zone->db != NULL) {
    dns_db_attach(zone->db, &db);
  }
  ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
  if (db == NULL) {
    goto cleanup;
  }

  dns_db_currentversion(db, &oldver);
  result = dns_db_newversion(db, &newver);
  if (result != ISC_R_SUCCESS) {
    dns_zone_log(zone, ISC_LOG_ERROR,
           "setserial:dns_db_newversion -> %s",
           isc_result_totext(result));
    goto cleanup;
  }

  CHECK(dns_db_createsoatuple(db, oldver, diff.mctx, DNS_DIFFOP_DEL,
            &oldtuple));
  dns_difftuple_copy(oldtuple, &newtuple);
  newtuple->op = DNS_DIFFOP_ADD;

  oldserial = dns_soa_getserial(&oldtuple->rdata);
  if (desired == 0U) {
    desired = 1;
  }
  if (!isc_serial_gt(desired, oldserial)) {
    if (desired != oldserial) {
      dns_zone_log(zone, ISC_LOG_INFO,
             "setserial: desired serial (%u) "
             "out of range (%u-%u)",
             desired, oldserial + 1,
             oldserial + 0x7fffffff);
    }
    goto cleanup;
  }

  dns_soa_setserial(desired, &newtuple->rdata);
  CHECK(dns_diff_applytuple(&oldtuple, db, newver, &diff));
  CHECK(dns_diff_applytuple(&newtuple, db, newver, &diff));
  result = dns_update_signatures(&log, zone, db, oldver, newver, &diff,
               zone->sigvalidityinterval);
  if (result != ISC_R_NOTFOUND) {
    CHECK(result);
  }

  /* Write changes to journal file. */
  CHECK(zone_journal(zone, &diff, NULL, "setserial"));
  commit = true;

  LOCK_ZONE(zone);
  zone_needdump(zone, 30);
  UNLOCK_ZONE(zone);

cleanup:
  if (oldtuple != NULL) {
    dns_difftuple_free(&oldtuple);
  }
  if (newtuple != NULL) {
    dns_difftuple_free(&newtuple);
  }
  if (oldver != NULL) {
    dns_db_closeversion(db, &oldver, false);
  }
  if (newver != NULL) {
    dns_db_closeversion(db, &newver, commit);
  }
  if (db != NULL) {
    dns_db_detach(&db);
  }
  dns_diff_clear(&diff);

disabled:
  INSIST(oldver == NULL);
  INSIST(newver == NULL);
}

isc_result_t
dns_zone_setserial(dns_zone_t *zone, uint32_t serial) {
  isc_result_t result = ISC_R_SUCCESS;
  zone_maintenance_request_t *request = NULL;

  REQUIRE(DNS_ZONE_VALID(zone));

  LOCK_ZONE(zone);

  if (!dns__zone_inline_secure(zone)) {
    if (!dns_zone_isdynamic(zone, true)) {
      CLEANUP(DNS_R_NOTDYNAMIC);
    }
  }

  if (zone->update_disabled) {
    CLEANUP(DNS_R_FROZEN);
  }

  request = isc_mem_get(zone->mctx, sizeof(*request));
  *request = (zone_maintenance_request_t){
    .link = ISC_LINK_INITIALIZER,
    .type = zone_maintenance_request_setserial,
    .u.setserial = {
      .serial = serial,
    },
  };
  ISC_LIST_APPEND(zone->maintenance_queue, request, link);
  if (zone->loop != NULL && zone_maintenance_request_pending(zone)) {
    isc_time_t now = isc_time_now();
    dns__zone_settimer(zone, now);
  }
  request = NULL;

cleanup:
  if (request != NULL) {
    isc_mem_put(zone->mctx, request, sizeof(*request));
  }
  UNLOCK_ZONE(zone);
  return result;
}

static void
zone_process_maintenance_request(dns_zone_t *zone) {
  zone_maintenance_request_t *request = NULL;

  LOCK_ZONE(zone);
  if (zone_maintenance_request_pending(zone)) {
    request = ISC_LIST_HEAD(zone->maintenance_queue);
    ISC_LIST_UNLINK(zone->maintenance_queue, request, link);
  }
  UNLOCK_ZONE(zone);

  if (request == NULL) {
    return;
  }

  switch (request->type) {
  case zone_maintenance_request_setnsec3param:
    rss_post(zone, &request->u.nsec3param);
    break;
  case zone_maintenance_request_keydone:
    zone_process_keydone(zone, request);
    break;
  case zone_maintenance_request_setserial:
    zone_process_setserial(zone, request);
    break;
  default:
    UNREACHABLE();
  }

  isc_mem_put(zone->mctx, request, sizeof(*request));
}

bool
dns_zone_isloaded(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED);
}

static void
db_namerd_tostr(dns_db_t *db, dns_view_t *view, char *buf, size_t length) {
  char originbuf[DNS_NAME_FORMATSIZE];
  char classbuf[DNS_RDATACLASS_FORMATSIZE];
  const char *viewname = "";

  dns_name_format(dns_db_origin(db), originbuf, sizeof(originbuf));
  dns_rdataclass_format(dns_db_class(db), classbuf, sizeof(classbuf));
  if (view != NULL && strcmp(view->name, "_bind") != 0 &&
      strcmp(view->name, "_default") != 0)
  {
    viewname = view->name;
  }
  snprintf(buf, length, "%.*s/%s%s%.1000s", DNS_NAME_MAXTEXT, originbuf,
     classbuf, viewname[0] != '\0' ? "/" : "", viewname);
}

isc_result_t
dns_zone_verifydb(dns_view_t *view, dns_db_t *db, dns_dbversion_t *ver) {
  dns_dbversion_t *version = NULL;
  dns_keytable_t *secroots = NULL;
  isc_result_t result;
  dns_name_t *origin;
  char name[2048];

  REQUIRE(view == NULL || DNS_VIEW_VALID(view));
  REQUIRE(db != NULL);

  db_namerd_tostr(db, view, name, sizeof(name));

  if (ver == NULL) {
    dns_db_currentversion(db, &version);
  } else {
    version = ver;
  }

  if (view != NULL) {
    result = dns_view_getsecroots(view, &secroots);
    CHECK(result);
  }

  origin = dns_db_origin(db);
  result = dns_zoneverify_dnssec(name, db, version, origin, secroots,
               db->mctx, true, false, dnssec_report);

cleanup:
  if (secroots != NULL) {
    dns_keytable_detach(&secroots);
  }

  if (ver == NULL) {
    dns_db_closeversion(db, &version, false);
  }

  if (result != ISC_R_SUCCESS) {
    isc_log_write(DNS_LOGCATEGORY_DNSSEC, DNS_LOGMODULE_ZONE,
            ISC_LOG_ERROR,
            "zone %s: zone verification failed: %s", name,
            isc_result_totext(result));
    result = DNS_R_VERIFYFAILURE;
  }

  return result;
}

static dns_ttl_t
zone_nsecttl(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return ISC_MIN(zone->minimum, zone->soattl);
}

void
dns_zonemgr_set_tlsctx_cache(dns_zonemgr_t *zmgr,
           isc_tlsctx_cache_t *tlsctx_cache) {
  REQUIRE(DNS_ZONEMGR_VALID(zmgr));
  REQUIRE(tlsctx_cache != NULL);

  RWLOCK(&zmgr->tlsctx_cache_rwlock, isc_rwlocktype_write);

  if (zmgr->tlsctx_cache != NULL) {
    isc_tlsctx_cache_detach(&zmgr->tlsctx_cache);
  }

  isc_tlsctx_cache_attach(tlsctx_cache, &zmgr->tlsctx_cache);

  RWUNLOCK(&zmgr->tlsctx_cache_rwlock, isc_rwlocktype_write);
}

void
dns__zonemgr_tlsctx_attach(dns_zonemgr_t *zmgr,
         isc_tlsctx_cache_t **ptlsctx_cache) {
  REQUIRE(DNS_ZONEMGR_VALID(zmgr));
  REQUIRE(ptlsctx_cache != NULL && *ptlsctx_cache == NULL);

  RWLOCK(&zmgr->tlsctx_cache_rwlock, isc_rwlocktype_read);

  INSIST(zmgr->tlsctx_cache != NULL);
  isc_tlsctx_cache_attach(zmgr->tlsctx_cache, ptlsctx_cache);

  RWUNLOCK(&zmgr->tlsctx_cache_rwlock, isc_rwlocktype_read);
}

isc_result_t
dns_zone_makedb(dns_zone_t *zone, dns_db_t **dbp) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(dbp != NULL && *dbp == NULL);

  dns_db_t *db = NULL;

  isc_result_t result = dns_db_create(
    zone->mctx, zone->db_argv[0], &zone->origin,
    (zone->type == dns_zone_stub) ? dns_dbtype_stub
                : dns_dbtype_zone,
    zone->rdclass, zone->db_argc - 1, zone->db_argv + 1, &db);
  if (result != ISC_R_SUCCESS) {
    return result;
  }

  switch (zone->type) {
  case dns_zone_primary:
  case dns_zone_secondary:
  case dns_zone_mirror:
    result = dns_db_setgluecachestats(db, zone->gluecachestats);
    if (result == ISC_R_NOTIMPLEMENTED) {
      result = ISC_R_SUCCESS;
    }
    if (result != ISC_R_SUCCESS) {
      dns_db_detach(&db);
      return result;
    }
    break;
  default:
    break;
  }

  dns_db_setmaxrrperset(db, zone->maxrrperset);
  dns_db_setmaxtypepername(db, zone->maxtypepername);

  *dbp = db;

  return ISC_R_SUCCESS;
}

isc_result_t
dns_zone_import_skr(dns_zone_t *zone, const char *file) {
  dns_skr_t *skr = NULL;
  isc_result_t result;

  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(zone->kasp != NULL);
  REQUIRE(file != NULL);

  dns_skr_create(zone->mctx, file, &zone->origin, zone->rdclass, &skr);

  CHECK(dns_skr_read(zone->mctx, file, &zone->origin, zone->rdclass,
         dns_kasp_dnskeyttl(zone->kasp), &skr));

  dns_zone_setskr(zone, skr);
  dnssec_log(zone, ISC_LOG_DEBUG(1), "imported skr file %s", file);

cleanup:
  dns_skr_detach(&skr);

  return result;
}

void
dns_zone_setplugins(dns_zone_t *zone, void *plugins) {
  REQUIRE(DNS_ZONE_VALID(zone));
  REQUIRE(zone->plugins == NULL);
  REQUIRE(zone->ops != NULL && zone->ops->plugins_free != NULL);

  zone->plugins = plugins;
}

void
dns_zone_unloadplugins(dns_zone_t *zone) {
  if (zone->hooktable != NULL) {
    INSIST(zone->ops->hooktable_free);
    zone->ops->hooktable_free(zone->mctx, &zone->hooktable);
    INSIST(zone->hooktable == NULL);
  }

  if (zone->plugins != NULL) {
    INSIST(zone->ops->plugins_free);
    zone->ops->plugins_free(zone->mctx, &zone->plugins);
    INSIST(zone->plugins == NULL);
  }
}

bool
dns_zone_isexpired(dns_zone_t *zone) {
  REQUIRE(DNS_ZONE_VALID(zone));

  return DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXPIRED);
}

Coverage Report

Created: 2026-10-28 06:54