/src/bind9/lib/dns/view.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 <inttypes.h>
#include <limits.h>
#include <lmdb.h>
#include <stdbool.h>

#include <isc/async.h>
#include <isc/atomic.h>
#include <isc/dir.h>
#include <isc/file.h>
#include <isc/hash.h>
#include <isc/lex.h>
#include <isc/md.h>
#include <isc/result.h>
#include <isc/stats.h>
#include <isc/string.h>
#include <isc/urcu.h>
#include <isc/util.h>

#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/badcache.h>
#include <dns/cache.h>
#include <dns/db.h>
#include <dns/dispatch.h>
#include <dns/dlz.h>
#include <dns/dns64.h>
#include <dns/dnssec.h>
#include <dns/forward.h>
#include <dns/keytable.h>
#include <dns/keyvalues.h>
#include <dns/master.h>
#include <dns/masterdump.h>
#include <dns/nametree.h>
#include <dns/nta.h>
#include <dns/order.h>
#include <dns/peer.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/request.h>
#include <dns/resolver.h>
#include <dns/rpz.h>
#include <dns/rrl.h>
#include <dns/stats.h>
#include <dns/time.h>
#include <dns/transport.h>
#include <dns/tsig.h>
#include <dns/unreachcache.h>
#include <dns/view.h>
#include <dns/zone.h>
#include <dns/zoneproperties.h>
#include <dns/zt.h>

#define DNS_VIEW_DELONLYHASH 111

/*%
 * Default maximum number of chained queries before we give up
 * to prevent CNAME loops.
 */
#define DEFAULT_MAX_RESTARTS 11

/*%
 * Default EDNS0 buffer size
 */
#define DEFAULT_EDNS_BUFSIZE 1232

/* Exponental backoff from 10 seconds to 640 seconds */
#define UNREACH_HOLD_TIME_INITIAL_SEC ((uint16_t)10)
#define UNREACH_HOLD_TIME_MAX_SEC     (UNREACH_HOLD_TIME_INITIAL_SEC << 6)
#define UNREACH_BACKOFF_ELIGIBLE_SEC  ((uint16_t)120)

void
dns_view_create(isc_mem_t *mctx, dns_dispatchmgr_t *dispatchmgr,
    dns_rdataclass_t rdclass, const char *name,
    dns_view_t **viewp) {
  dns_view_t *view = NULL;
  isc_result_t result;
  char buffer[1024];

  REQUIRE(name != NULL);
  REQUIRE(viewp != NULL && *viewp == NULL);

  switch (rdclass) {
  case dns_rdataclass_in:
    break;
  case dns_rdataclass_chaos:
    if (strcmp(name, "_bind") == 0) {
      /* allowed */
      break;
    }
    FALLTHROUGH;
  default:
    UNREACHABLE();
  }

  result = isc_file_sanitize(NULL, name, "nta", buffer, sizeof(buffer));
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  view = isc_mem_get(mctx, sizeof(*view));
  *view = (dns_view_t){
    .rdclass = rdclass,
    .name = isc_mem_strdup(mctx, name),
    .nta_file = isc_mem_strdup(mctx, buffer),
    .recursion = true,
    .enablevalidation = true,
    .minimalresponses = dns_minimal_no,
    .transfer_format = dns_one_answer,
    .msgcompression = true,
    .provideixfr = true,
    .maxcachettl = 7 * 24 * 3600,
    .maxncachettl = 3 * 3600,
    .dstport = 53,
    .staleanswerttl = 1,
    .staleanswersok = dns_stale_answer_conf,
    .sendcookie = true,
    .synthfromdnssec = true,
    .trust_anchor_telemetry = true,
    .root_key_sentinel = true,
    .udpsize = DEFAULT_EDNS_BUFSIZE,
    .max_restarts = DEFAULT_MAX_RESTARTS,
  };

  isc_refcount_init(&view->references, 1);
  isc_refcount_init(&view->weakrefs, 1);

  dns_fixedname_init(&view->redirectfixed);

  ISC_LIST_INIT(view->dlz_searched);
  ISC_LIST_INIT(view->dlz_unsearched);
  ISC_LIST_INIT(view->dns64);

  ISC_LINK_INIT(view, link);

  isc_mem_attach(mctx, &view->mctx);

  if (dispatchmgr != NULL) {
    dns_dispatchmgr_attach(dispatchmgr, &view->dispatchmgr);
  }

  isc_mutex_init(&view->lock);

  dns_zt_create(mctx, view, &view->zonetable);

  dns_fwdtable_create(mctx, view, &view->fwdtable);

  dns_tsigkeyring_create(view->mctx, &view->dynamickeys);

  view->failcache = dns_badcache_new(view->mctx);

  view->unreachcache = dns_unreachcache_new(
    view->mctx, UNREACH_HOLD_TIME_INITIAL_SEC,
    UNREACH_HOLD_TIME_MAX_SEC, UNREACH_BACKOFF_ELIGIBLE_SEC);

  isc_mutex_init(&view->newzone.lock);

  dns_order_create(view->mctx, &view->order);

  dns_peerlist_new(view->mctx, &view->peers);

  dns_aclenv_create(view->mctx, &view->aclenv);

  dns_nametree_create(view->mctx, DNS_NAMETREE_COUNT, "sfd", &view->sfd);

  view->magic = DNS_VIEW_MAGIC;
  *viewp = view;
}

static void
destroy(dns_view_t *view) {
  dns_dns64_t *dns64 = NULL;

  REQUIRE(!ISC_LINK_LINKED(view, link));

  isc_refcount_destroy(&view->references);
  isc_refcount_destroy(&view->weakrefs);

  if (view->deleg != NULL) {
    dns_delegdb_detach(&view->deleg);
  }

  if (view->order != NULL) {
    dns_order_detach(&view->order);
  }
  if (view->peers != NULL) {
    dns_peerlist_detach(&view->peers);
  }

  if (view->dynamickeys != NULL) {
    isc_result_t result;
    char template[PATH_MAX];
    char keyfile[PATH_MAX];
    FILE *fp = NULL;

    result = isc_file_mktemplate(NULL, template, sizeof(template));
    if (result == ISC_R_SUCCESS) {
      (void)isc_file_openuniqueprivate(template, &fp);
    }
    if (fp != NULL) {
      result = dns_tsigkeyring_dump(view->dynamickeys, fp);
      if (result == ISC_R_SUCCESS) {
        if (fclose(fp) == 0) {
          result = isc_file_sanitize(
            NULL, view->name, "tsigkeys",
            keyfile, sizeof(keyfile));
          if (result == ISC_R_SUCCESS) {
            result = isc_file_rename(
              template, keyfile);
          }
        }
        if (result != ISC_R_SUCCESS) {
          (void)remove(template);
        }
      } else {
        (void)fclose(fp);
        (void)remove(template);
      }
    }
    dns_tsigkeyring_detach(&view->dynamickeys);
  }
  if (view->transports != NULL) {
    dns_transport_list_detach(&view->transports);
  }
  if (view->statickeys != NULL) {
    dns_tsigkeyring_detach(&view->statickeys);
  }

  /* These must have been detached in dns_view_detach() */
  INSIST(view->adb == NULL);
  INSIST(view->resolver == NULL);
  INSIST(view->requestmgr == NULL);

  dns_rrl_view_destroy(view);
  if (view->rpzs != NULL) {
    dns_rpz_zones_shutdown(view->rpzs);
    dns_rpz_zones_detach(&view->rpzs);
  }
  if (view->catzs != NULL) {
    dns_catz_zones_shutdown(view->catzs);
    dns_catz_zones_detach(&view->catzs);
  }
  ISC_LIST_FOREACH(view->dlz_searched, dlzdb, link) {
    ISC_LIST_UNLINK(view->dlz_searched, dlzdb, link);
    dns_dlzdestroy(&dlzdb);
  }
  ISC_LIST_FOREACH(view->dlz_unsearched, dlzdb, link) {
    ISC_LIST_UNLINK(view->dlz_unsearched, dlzdb, link);
    dns_dlzdestroy(&dlzdb);
  }
  if (view->cachedb != NULL) {
    dns_db_detach(&view->cachedb);
  }
  if (view->cache != NULL) {
    dns_cache_detach(&view->cache);
  }
  if (view->nocasecompress != NULL) {
    dns_acl_detach(&view->nocasecompress);
  }
  if (view->matchclients != NULL) {
    dns_acl_detach(&view->matchclients);
  }
  if (view->matchdestinations != NULL) {
    dns_acl_detach(&view->matchdestinations);
  }
  if (view->cacheacl != NULL) {
    dns_acl_detach(&view->cacheacl);
  }
  if (view->cacheonacl != NULL) {
    dns_acl_detach(&view->cacheonacl);
  }
  if (view->queryacl != NULL) {
    dns_acl_detach(&view->queryacl);
  }
  if (view->queryonacl != NULL) {
    dns_acl_detach(&view->queryonacl);
  }
  if (view->recursionacl != NULL) {
    dns_acl_detach(&view->recursionacl);
  }
  if (view->recursiononacl != NULL) {
    dns_acl_detach(&view->recursiononacl);
  }
  if (view->transferacl != NULL) {
    dns_acl_detach(&view->transferacl);
  }
  if (view->notifyacl != NULL) {
    dns_acl_detach(&view->notifyacl);
  }
  if (view->updateacl != NULL) {
    dns_acl_detach(&view->updateacl);
  }
  if (view->upfwdacl != NULL) {
    dns_acl_detach(&view->upfwdacl);
  }
  if (view->denyansweracl != NULL) {
    dns_acl_detach(&view->denyansweracl);
  }
  if (view->pad_acl != NULL) {
    dns_acl_detach(&view->pad_acl);
  }
  if (view->proxyacl != NULL) {
    dns_acl_detach(&view->proxyacl);
  }
  if (view->proxyonacl != NULL) {
    dns_acl_detach(&view->proxyonacl);
  }
  if (view->answeracl_exclude != NULL) {
    dns_nametree_detach(&view->answeracl_exclude);
  }
  if (view->denyanswernames != NULL) {
    dns_nametree_detach(&view->denyanswernames);
  }
  if (view->answernames_exclude != NULL) {
    dns_nametree_detach(&view->answernames_exclude);
  }
  if (view->sfd != NULL) {
    dns_nametree_detach(&view->sfd);
  }
  if (view->secroots_priv != NULL) {
    dns_keytable_detach(&view->secroots_priv);
  }
  if (view->ntatable_priv != NULL) {
    dns_ntatable_detach(&view->ntatable_priv);
  }
  for (dns64 = ISC_LIST_HEAD(view->dns64); dns64 != NULL;
       dns64 = ISC_LIST_HEAD(view->dns64))
  {
    dns_dns64_destroy(&view->dns64, &dns64);
  }
  if (view->managed_keys != NULL) {
    dns_zone_detach(&view->managed_keys);
  }
  if (view->redirect != NULL) {
    dns_zone_detach(&view->redirect);
  }
#ifdef HAVE_DNSTAP
  if (view->dtenv != NULL) {
    dns_dtenv_detach(&view->dtenv);
  }
#endif /* HAVE_DNSTAP */
  if (view->newzone.cleanup != NULL) {
    view->newzone.cleanup(view);
  }
  if (view->newzone.dbenv != NULL) {
    mdb_env_close((MDB_env *)view->newzone.dbenv);
    view->newzone.dbenv = NULL;
  }
  if (view->newzone.db != NULL) {
    isc_mem_free(view->mctx, view->newzone.db);
  }
  dns_fwdtable_destroy(&view->fwdtable);
  dns_aclenv_detach(&view->aclenv);
  if (view->failcache != NULL) {
    dns_badcache_destroy(&view->failcache);
  }
  if (view->unreachcache != NULL) {
    dns_unreachcache_destroy(&view->unreachcache);
  }
  isc_mutex_destroy(&view->newzone.lock);
  isc_mutex_destroy(&view->lock);
  isc_refcount_destroy(&view->references);
  isc_refcount_destroy(&view->weakrefs);
  isc_mem_free(view->mctx, view->nta_file);
  isc_mem_free(view->mctx, view->name);
  if (view->hooktable != NULL && view->hooktable_free != NULL) {
    view->hooktable_free(view->mctx, &view->hooktable);
  }
  if (view->plugins != NULL && view->plugins_free != NULL) {
    view->plugins_free(view->mctx, &view->plugins);
  }
  isc_mem_putanddetach(&view->mctx, view, sizeof(*view));
}

void
dns_view_attach(dns_view_t *source, dns_view_t **targetp) {
  REQUIRE(DNS_VIEW_VALID(source));
  REQUIRE(targetp != NULL && *targetp == NULL);

  isc_refcount_increment(&source->references);

  *targetp = source;
}

static void
shutdown_view(dns_view_t *view) {
  dns_zone_t *mkzone = NULL, *rdzone = NULL;
  dns_zt_t *zonetable = NULL;
  dns_resolver_t *resolver = NULL;
  dns_adb_t *adb = NULL;
  dns_requestmgr_t *requestmgr = NULL;
  dns_dispatchmgr_t *dispatchmgr = NULL;

  isc_refcount_destroy(&view->references);

  /* Shutdown the attached objects first */
  if (view->resolver != NULL) {
    dns_resolver_shutdown(view->resolver);
  }

  rcu_read_lock();
  adb = rcu_dereference(view->adb);
  if (adb != NULL) {
    dns_adb_shutdown(adb);
  }
  rcu_read_unlock();

  if (view->requestmgr != NULL) {
    dns_requestmgr_shutdown(view->requestmgr);
  }

  /* Swap the pointers under the lock */
  LOCK(&view->lock);

  if (view->resolver != NULL) {
    resolver = view->resolver;
    view->resolver = NULL;
  }

  rcu_read_lock();
  zonetable = rcu_xchg_pointer(&view->zonetable, NULL);
  if (zonetable != NULL) {
    if (view->flush) {
      dns_zt_flush(zonetable);
    }
  }
  adb = rcu_xchg_pointer(&view->adb, NULL);
  dispatchmgr = rcu_xchg_pointer(&view->dispatchmgr, NULL);
  rcu_read_unlock();

  if (view->requestmgr != NULL) {
    requestmgr = view->requestmgr;
    view->requestmgr = NULL;
  }
  if (view->managed_keys != NULL) {
    mkzone = view->managed_keys;
    view->managed_keys = NULL;
    if (view->flush) {
      dns_zone_flush(mkzone);
    }
  }
  if (view->redirect != NULL) {
    rdzone = view->redirect;
    view->redirect = NULL;
    if (view->flush) {
      dns_zone_flush(rdzone);
    }
  }
  if (view->catzs != NULL) {
    dns_catz_zones_shutdown(view->catzs);
    dns_catz_zones_detach(&view->catzs);
  }
  if (view->ntatable_priv != NULL) {
    dns_ntatable_shutdown(view->ntatable_priv);
  }
  UNLOCK(&view->lock);

  /* Detach outside view lock */
  if (resolver != NULL) {
    dns_resolver_detach(&resolver);
  }

  synchronize_rcu();
  if (dispatchmgr != NULL) {
    dns_dispatchmgr_detach(&dispatchmgr);
  }
  if (adb != NULL) {
    dns_adb_detach(&adb);
  }
  if (zonetable != NULL) {
    dns_zt_detach(&zonetable);
  }
  if (requestmgr != NULL) {
    dns_requestmgr_detach(&requestmgr);
  }
  if (mkzone != NULL) {
    dns_zone_detach(&mkzone);
  }
  if (rdzone != NULL) {
    dns_zone_detach(&rdzone);
  }

  dns_view_weakdetach(&view);
}

void
dns_view_detach(dns_view_t **viewp) {
  dns_view_t *view = NULL;

  REQUIRE(viewp != NULL && DNS_VIEW_VALID(*viewp));

  view = *viewp;
  *viewp = NULL;

  if (isc_refcount_decrement(&view->references) == 1) {
    shutdown_view(view);
  }
}

void
dns_view_weakattach(dns_view_t *source, dns_view_t **targetp) {
  REQUIRE(DNS_VIEW_VALID(source));
  REQUIRE(targetp != NULL && *targetp == NULL);

  isc_refcount_increment(&source->weakrefs);

  *targetp = source;
}

void
dns_view_weakdetach(dns_view_t **viewp) {
  dns_view_t *view = NULL;

  REQUIRE(viewp != NULL);

  view = *viewp;
  *viewp = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  if (isc_refcount_decrement(&view->weakrefs) == 1) {
    destroy(view);
  }
}

isc_result_t
dns_view_createresolver(dns_view_t *view, unsigned int options,
      isc_tlsctx_cache_t *tlsctx_cache,
      dns_dispatch_t *dispatchv4,
      dns_dispatch_t *dispatchv6) {
  isc_result_t result;
  isc_mem_t *mctx = NULL;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(!view->frozen);
  REQUIRE(view->resolver == NULL);
  REQUIRE(view->dispatchmgr != NULL);

  RETERR(dns_resolver_create(view, options, tlsctx_cache, dispatchv4,
           dispatchv6, &view->resolver));

  isc_mem_create("ADB", &mctx);
  dns_adb_create(mctx, view, &view->adb);
  isc_mem_detach(&mctx);

  result = dns_requestmgr_create(view->mctx, view->dispatchmgr,
               dispatchv4, dispatchv6,
               &view->requestmgr);
  if (result != ISC_R_SUCCESS) {
    goto cleanup_adb;
  }

  return ISC_R_SUCCESS;

cleanup_adb:
  dns_adb_shutdown(view->adb);
  dns_adb_detach(&view->adb);

  dns_resolver_shutdown(view->resolver);
  dns_resolver_detach(&view->resolver);

  return result;
}

void
dns_view_setcache(dns_view_t *view, dns_cache_t *cache, bool shared) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(!view->frozen);

  view->cacheshared = shared;
  if (view->cache != NULL) {
    dns_db_detach(&view->cachedb);
    dns_cache_detach(&view->cache);
  }
  dns_cache_attach(cache, &view->cache);
  dns_cache_attachdb(cache, &view->cachedb);
  INSIST(DNS_DB_VALID(view->cachedb));

  dns_cache_setmaxrrperset(view->cache, view->maxrrperset);
  dns_cache_setmaxtypepername(view->cache, view->maxtypepername);
}

bool
dns_view_iscacheshared(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));

  return view->cacheshared;
}

void
dns_view_settransports(dns_view_t *view, dns_transport_list_t *list) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(list != NULL);
  if (view->transports != NULL) {
    dns_transport_list_detach(&view->transports);
  }
  dns_transport_list_attach(list, &view->transports);
}

void
dns_view_setkeyring(dns_view_t *view, dns_tsigkeyring_t *ring) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(ring != NULL);
  if (view->statickeys != NULL) {
    dns_tsigkeyring_detach(&view->statickeys);
  }
  dns_tsigkeyring_attach(ring, &view->statickeys);
}

void
dns_view_setdynamickeyring(dns_view_t *view, dns_tsigkeyring_t *ring) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(ring != NULL);
  if (view->dynamickeys != NULL) {
    dns_tsigkeyring_detach(&view->dynamickeys);
  }
  dns_tsigkeyring_attach(ring, &view->dynamickeys);
}

void
dns_view_getdynamickeyring(dns_view_t *view, dns_tsigkeyring_t **ringp) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(ringp != NULL && *ringp == NULL);
  if (view->dynamickeys != NULL) {
    dns_tsigkeyring_attach(view->dynamickeys, ringp);
  }
}

void
dns_view_restorekeyring(dns_view_t *view) {
  FILE *fp;
  char keyfile[PATH_MAX];
  isc_result_t result;

  REQUIRE(DNS_VIEW_VALID(view));

  if (view->dynamickeys != NULL) {
    result = isc_file_sanitize(NULL, view->name, "tsigkeys",
             keyfile, sizeof(keyfile));
    if (result == ISC_R_SUCCESS) {
      fp = fopen(keyfile, "r");
      if (fp != NULL) {
        dns_tsigkeyring_restore(view->dynamickeys, fp);
        (void)fclose(fp);
      }
    }
  }
}

void
dns_view_setdstport(dns_view_t *view, in_port_t dstport) {
  REQUIRE(DNS_VIEW_VALID(view));
  view->dstport = dstport;
}

void
dns_view_freeze(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(!view->frozen);

  if (view->resolver != NULL) {
    INSIST(view->cachedb != NULL);
    dns_resolver_freeze(view->resolver);
  }
  view->frozen = true;
}

void
dns_view_thaw(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(view->frozen);

  view->frozen = false;
}

isc_result_t
dns_view_addzone(dns_view_t *view, dns_zone_t *zone) {
  isc_result_t result;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(!view->frozen);

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_mount(zonetable, zone);
  } else {
    result = ISC_R_SHUTTINGDOWN;
  }
  rcu_read_unlock();

  return result;
}

isc_result_t
dns_view_delzone(dns_view_t *view, dns_zone_t *zone) {
  isc_result_t result;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  dns_zone_prepare_shutdown(zone);

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_unmount(zonetable, zone);
  } else {
    result = ISC_R_SUCCESS;
  }
  rcu_read_unlock();

  return result;
}

isc_result_t
dns_view_findzone(dns_view_t *view, const dns_name_t *name,
      unsigned int options, dns_zone_t **zonep) {
  isc_result_t result;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_find(zonetable, name, options, zonep);
  } else {
    result = ISC_R_NOTFOUND;
  }
  rcu_read_unlock();

  return result;
}

isc_result_t
dns_view_find(dns_view_t *view, const dns_name_t *name, dns_rdatatype_t type,
        isc_stdtime_t now, unsigned int options, bool use_static_stub,
        dns_db_t **dbp, dns_name_t *foundname, dns_rdataset_t *rdataset,
        dns_rdataset_t *sigrdataset) {
  isc_result_t result;
  dns_db_t *db = NULL, *zdb = NULL;
  bool is_cache, is_staticstub_zone;
  dns_rdataset_t zrdataset, zsigrdataset;
  dns_zone_t *zone = NULL;
  dns_zt_t *zonetable = NULL;

  /*
   * Find an rdataset whose owner name is 'name', and whose type is
   * 'type'.
   */

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(view->frozen);
  REQUIRE(type != dns_rdatatype_rrsig);
  REQUIRE(rdataset != NULL); /* XXXBEW - remove this */

  /*
   * Initialize.
   */
  dns_rdataset_init(&zrdataset);
  dns_rdataset_init(&zsigrdataset);

  /*
   * Find a database to answer the query.
   */
  is_staticstub_zone = false;
  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_find(zonetable, name, DNS_ZTFIND_MIRROR, &zone);
  } else {
    result = ISC_R_SHUTTINGDOWN;
  }
  rcu_read_unlock();
  if (zone != NULL && dns_zone_gettype(zone) == dns_zone_staticstub &&
      !use_static_stub)
  {
    result = ISC_R_NOTFOUND;
  }
  if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
    result = dns_zone_getdb(zone, &db);
    if (result != ISC_R_SUCCESS && view->cachedb != NULL) {
      dns_db_attach(view->cachedb, &db);
    } else if (result != ISC_R_SUCCESS) {
      goto cleanup;
    }
    if (dns_zone_gettype(zone) == dns_zone_staticstub &&
        dns_name_equal(name, dns_zone_getorigin(zone)))
    {
      is_staticstub_zone = true;
    }
  } else if (result == ISC_R_NOTFOUND && view->cachedb != NULL) {
    dns_db_attach(view->cachedb, &db);
  } else {
    goto cleanup;
  }

  is_cache = dns_db_iscache(db);

db_find:
  /*
   * Now look for an answer in the database.
   */
  result = dns_db_find(db, name, NULL, type, options, now, foundname,
           rdataset, sigrdataset);

  if (result == DNS_R_DELEGATION || result == ISC_R_NOTFOUND) {
    dns_rdataset_cleanup(rdataset);
    dns_rdataset_cleanup(sigrdataset);
    if (!is_cache) {
      dns_db_detach(&db);
      if (view->cachedb != NULL && !is_staticstub_zone) {
        /*
         * Either the answer is in the cache, or we
         * don't know it.
         * Note that if the result comes from a
         * static-stub zone we stop the search here
         * (see the function description in view.h).
         */
        is_cache = true;
        dns_db_attach(view->cachedb, &db);
        goto db_find;
      }
    } else {
      /*
       * We don't have the data in the cache.  If we've got
       * glue from the zone, use it.
       */
      if (dns_rdataset_isassociated(&zrdataset)) {
        dns_rdataset_clone(&zrdataset, rdataset);
        if (sigrdataset != NULL &&
            dns_rdataset_isassociated(&zsigrdataset))
        {
          dns_rdataset_clone(&zsigrdataset,
                 sigrdataset);
        }
        result = DNS_R_GLUE;
        if (db != NULL) {
          dns_db_detach(&db);
        }
        dns_db_attach(zdb, &db);
        goto cleanup;
      }
    }
    /*
     * We don't know the answer.
     */
    result = ISC_R_NOTFOUND;
  } else if (result == DNS_R_GLUE) {
    /*
     * Glue is the answer wanted.
     */
    result = ISC_R_SUCCESS;
  }

cleanup:
  dns_rdataset_cleanup(&zrdataset);
  dns_rdataset_cleanup(&zsigrdataset);

  if (zdb != NULL) {
    dns_db_detach(&zdb);
  }

  if (db != NULL) {
    if (dbp != NULL) {
      *dbp = db;
    } else {
      dns_db_detach(&db);
    }
  }

  if (zone != NULL) {
    dns_zone_detach(&zone);
  }

  return result;
}

isc_result_t
dns_view_simplefind(dns_view_t *view, const dns_name_t *name,
        dns_rdatatype_t type, isc_stdtime_t now,
        unsigned int options, dns_rdataset_t *rdataset,
        dns_rdataset_t *sigrdataset) {
  isc_result_t result;
  dns_fixedname_t foundname;

  dns_fixedname_init(&foundname);
  result = dns_view_find(view, name, type, now, options, false, NULL,
             dns_fixedname_name(&foundname), rdataset,
             sigrdataset);
  if (result == DNS_R_NXDOMAIN) {
    /*
     * The rdataset and sigrdataset of the relevant NSEC record
     * may be returned, but the caller cannot use them because
     * foundname is not returned by this simplified API.  We
     * disassociate them here to prevent any misuse by the caller.
     */
    dns_rdataset_cleanup(rdataset);
    dns_rdataset_cleanup(sigrdataset);
  } else if (result != ISC_R_SUCCESS && result != DNS_R_GLUE &&
       result != DNS_R_HINT && result != DNS_R_NCACHENXDOMAIN &&
       result != DNS_R_NCACHENXRRSET && result != DNS_R_NXRRSET &&
       result != DNS_R_HINTNXRRSET && result != ISC_R_NOTFOUND)
  {
    dns_rdataset_cleanup(rdataset);
    dns_rdataset_cleanup(sigrdataset);
    result = ISC_R_NOTFOUND;
  }

  return result;
}

static isc_result_t
bestzonecut_zone(dns_view_t *view, const dns_name_t *name, dns_name_t *fname,
     dns_name_t *dcname, isc_stdtime_t now, unsigned int options,
     dns_rdataset_t *rdataset) {
  dns_db_t *db = NULL;
  dns_zone_t *zone = NULL;
  unsigned int ztoptions = DNS_ZTFIND_MIRROR;
  isc_result_t result;

  if ((options & DNS_DBFIND_ABOVE) != 0) {
    ztoptions |= DNS_ZTFIND_NOEXACT;
  }

  result = dns_view_findzone(view, name, ztoptions, &zone);
  if (result != ISC_R_SUCCESS && result != DNS_R_PARTIALMATCH) {
    /*
     * There is no matching zone configured locally.
     */
    CLEANUP(DNS_R_NXDOMAIN);
  }

  result = dns_zone_getdb(zone, &db);
  if (result != ISC_R_SUCCESS) {
    /*
     * A matching zone is configured locally, but its database
     * isn't loaded. We return ISC_R_NOTFOUND to differentiate
     * from the case where the zone doesn't exist, so the
     * caller won't try the cache or hints.
     */
    CLEANUP(ISC_R_NOTFOUND);
  }

  result = dns_db_find(db, name, NULL, dns_rdatatype_ns, options, now,
           fname, rdataset, NULL);
  if (result != DNS_R_DELEGATION && result != ISC_R_SUCCESS) {
    /*
     * The zone exists, but there is no delegation. Here again
     * we use ISC_R_NOTFOUND, to differentiate from the case where
     * the zone doesn't exist.
     */
    CLEANUP(ISC_R_NOTFOUND);
  }

  /*
   * Tag static stub NS RRset so that when we look for
   * addresses we use the configured server addresses.
   */
  if (dns_zone_gettype(zone) == dns_zone_staticstub) {
    rdataset->attributes.staticstub = true;
  }

  if (dcname != NULL) {
    dns_name_copy(fname, dcname);
  }

  result = ISC_R_SUCCESS;

cleanup:
  if (result != ISC_R_SUCCESS) {
    dns_rdataset_cleanup(rdataset);
  }

  if (db != NULL) {
    dns_db_detach(&db);
  }

  if (zone != NULL) {
    dns_zone_detach(&zone);
  }

  return result;
}

static isc_result_t
bestzonecut_delegdb(dns_view_t *view, const dns_name_t *name, dns_name_t *fname,
        dns_name_t *dcname, isc_stdtime_t now, unsigned int options,
        dns_delegset_t **delegsetp) {
  isc_result_t result = DNS_R_NXDOMAIN;

  if (view->deleg != NULL) {
    result = dns_delegdb_lookup(view->deleg, name, now, options,
              fname, dcname, delegsetp);
  }

  if (result == DNS_R_EXPIRED) {
    dns_resolver_t *res = NULL;

    INSIST((options & DNS_DBFIND_HINTOK) != 0);
    if (dns_view_getresolver(view, &res) == ISC_R_SUCCESS) {
      dns_resolver_prime(res);
      dns_resolver_detach(&res);
    }

    result = ISC_R_SUCCESS;
  }

  /*
   * Cache miss returns ISC_R_NOTFOUND, but to not confuse it
   * with a zone found without delegation matching `name` (nor partial),
   * keep DNS_R_NXDOMAIN, so the hints can be checked.
   */
  if (result != ISC_R_SUCCESS) {
    result = DNS_R_NXDOMAIN;
  }
  return result;
}

static void
bestzonecut_zoneorcache(dns_view_t *view, const dns_name_t *name,
      dns_name_t *fname, dns_name_t *dcname,
      isc_stdtime_t now, unsigned int options,
      dns_rdataset_t *rdataset, dns_delegset_t **delegsetp) {
  isc_result_t result;
  dns_fixedname_t f, dc;
  dns_name_t *cfname = dns_fixedname_initname(&f);
  dns_name_t *cdcname = dns_fixedname_initname(&dc);

  result = bestzonecut_delegdb(view, name, cfname, cdcname, now, options,
             delegsetp);
  if (result != ISC_R_SUCCESS) {
    return;
  }

  bool cacheclosest = dns_name_issubdomain(cfname, fname);
  bool staticstub = rdataset->attributes.staticstub &&
        dns_name_equal(fname, cfname);

  if (cacheclosest && !staticstub) {
    dns_rdataset_cleanup(rdataset);

    dns_name_copy(cfname, fname);
    if (dcname != NULL) {
      dns_name_copy(cdcname, dcname);
    }
  } else {
    dns_delegset_detach(delegsetp);
  }
}

isc_result_t
dns_view_bestzonecut(dns_view_t *view, const dns_name_t *name,
         dns_name_t *fname, dns_name_t *dcname, isc_stdtime_t now,
         unsigned int options, bool usehints, bool usecache,
         dns_delegset_t **delegsetp) {
  isc_result_t result;
  dns_rdataset_t rdataset = DNS_RDATASET_INIT;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(view->frozen);
  REQUIRE(delegsetp == NULL || *delegsetp == NULL);

  if (usehints) {
    options |= DNS_DBFIND_HINTOK;
  }

  result = bestzonecut_zone(view, name, fname, dcname, now, options,
          &rdataset);

  if (result == DNS_R_NXDOMAIN && usecache) {
    /*
     * No local zone matches `name`, but the cache might have a
     * delegation.
     */
    result = bestzonecut_delegdb(view, name, fname, dcname, now,
               options, delegsetp);
  } else if (result == ISC_R_SUCCESS && usecache) {
    /*
     * A zone with a (possibly partial) delegation match but the
     * cache can have a more precise delegation.
     *
     * No need to look for hints in this case: we have something
     * better in a local zone.
     */
    options &= ~DNS_DBFIND_HINTOK;
    bestzonecut_zoneorcache(view, name, fname, dcname, now, options,
          &rdataset, delegsetp);
  }

  if (result != ISC_R_SUCCESS) {
    result = DNS_R_NXDOMAIN;
  } else {
    /*
     * The rdataset came either from a local zone or a hint. Either
     * way, we only considering the NS rdataset here, so if there
     * are glues, they'll be ignored. This is okay: the delegation
     * type will be DNS_DELEGSET_NS_NAMES, so ADB will do a NS name
     * lookup but immediately find the results locally (because this
     * came from a local zone or hint). So the resolution will be
     * the same, and this avoid adding extra code here to extract
     * A/AAAA rdataset if any.
     */
    dns_delegset_fromnsrdataset(view->mctx, &rdataset, delegsetp);
  }

  dns_rdataset_cleanup(&rdataset);
  return result;
}

isc_result_t
dns_viewlist_find(dns_viewlist_t *list, const char *name,
      dns_rdataclass_t rdclass, dns_view_t **viewp) {
  REQUIRE(list != NULL);

  ISC_LIST_FOREACH(*list, view, link) {
    if (strcmp(view->name, name) == 0 && view->rdclass == rdclass) {
      dns_view_attach(view, viewp);
      return ISC_R_SUCCESS;
    }
  }

  return ISC_R_NOTFOUND;
}

isc_result_t
dns_viewlist_findzone(dns_viewlist_t *list, const dns_name_t *name,
          bool allclasses, dns_rdataclass_t rdclass,
          dns_zone_t **zonep) {
  isc_result_t result;
  dns_zone_t *zone1 = NULL, *zone2 = NULL;

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

  ISC_LIST_FOREACH(*list, view, link) {
    dns_zt_t *zonetable = NULL;
    if (!allclasses && view->rdclass != rdclass) {
      continue;
    }
    rcu_read_lock();
    zonetable = rcu_dereference(view->zonetable);
    if (zonetable != NULL) {
      result = dns_zt_find(zonetable, name, DNS_ZTFIND_EXACT,
               (zone1 == NULL) ? &zone1 : &zone2);
    } else {
      result = ISC_R_NOTFOUND;
    }
    rcu_read_unlock();
    INSIST(result == ISC_R_SUCCESS || result == ISC_R_NOTFOUND);
    if (zone2 != NULL) {
      dns_zone_detach(&zone1);
      dns_zone_detach(&zone2);
      return ISC_R_MULTIPLE;
    }
  }

  if (zone1 != NULL) {
    dns_zone_attach(zone1, zonep);
    dns_zone_detach(&zone1);
    return ISC_R_SUCCESS;
  }

  return ISC_R_NOTFOUND;
}

isc_result_t
dns_view_asyncload(dns_view_t *view, bool newonly, dns_zt_callback_t *callback,
       void *arg) {
  isc_result_t result;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_asyncload(zonetable, newonly, callback, arg);
  } else {
    result = ISC_R_SUCCESS;
  }
  rcu_read_unlock();
  return result;
}

isc_result_t
dns_view_gettsig(dns_view_t *view, const dns_name_t *keyname,
     dns_tsigkey_t **keyp) {
  isc_result_t result;
  REQUIRE(keyp != NULL && *keyp == NULL);

  result = dns_tsigkey_find(keyp, keyname, NULL, view->statickeys);
  if (result == ISC_R_NOTFOUND) {
    result = dns_tsigkey_find(keyp, keyname, NULL,
            view->dynamickeys);
  }
  return result;
}

isc_result_t
dns_view_gettransport(dns_view_t *view, const dns_transport_type_t type,
          const dns_name_t *name, dns_transport_t **transportp) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(transportp != NULL && *transportp == NULL);

  dns_transport_t *transport = dns_transport_find(type, name,
              view->transports);
  if (transport == NULL) {
    return ISC_R_NOTFOUND;
  }

  *transportp = transport;
  return ISC_R_SUCCESS;
}

isc_result_t
dns_view_getpeertsig(dns_view_t *view, const isc_netaddr_t *peeraddr,
         dns_tsigkey_t **keyp) {
  isc_result_t result;
  dns_name_t *keyname = NULL;
  dns_peer_t *peer = NULL;

  RETERR(dns_peerlist_peerbyaddr(view->peers, peeraddr, &peer));

  RETERR(dns_peer_getkey(peer, &keyname));

  result = dns_view_gettsig(view, keyname, keyp);
  return (result == ISC_R_NOTFOUND) ? ISC_R_FAILURE : result;
}

isc_result_t
dns_view_checksig(dns_view_t *view, isc_buffer_t *source, dns_message_t *msg) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(source != NULL);

  return dns_tsig_verify(source, msg, view->statickeys,
             view->dynamickeys);
}

isc_result_t
dns_view_flushcache(dns_view_t *view, bool fixuponly) {
  dns_adb_t *adb = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  if (view->cachedb == NULL) {
    return ISC_R_SUCCESS;
  }
  if (!fixuponly) {
    RETERR(dns_cache_flush(view->cache));
  }
  dns_db_detach(&view->cachedb);
  dns_cache_attachdb(view->cache, &view->cachedb);
  if (view->failcache != NULL) {
    dns_badcache_flush(view->failcache);
  }
  if (view->unreachcache != NULL) {
    dns_unreachcache_flush(view->unreachcache);
  }

  rcu_read_lock();
  adb = rcu_dereference(view->adb);
  if (adb != NULL) {
    dns_adb_flush(adb);
  }
  rcu_read_unlock();

  return ISC_R_SUCCESS;
}

isc_result_t
dns_view_flushname(dns_view_t *view, const dns_name_t *name) {
  return dns_view_flushnode(view, name, false);
}

isc_result_t
dns_view_flushnode(dns_view_t *view, const dns_name_t *name, bool tree) {
  isc_result_t result = ISC_R_SUCCESS;
  dns_adb_t *adb = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  if (tree) {
    rcu_read_lock();
    adb = rcu_dereference(view->adb);
    if (adb != NULL) {
      dns_adb_flushnames(adb, name);
    }
    rcu_read_unlock();
    if (view->failcache != NULL) {
      dns_badcache_flushtree(view->failcache, name);
    }
  } else {
    rcu_read_lock();
    adb = rcu_dereference(view->adb);
    if (adb != NULL) {
      dns_adb_flushname(adb, name);
    }
    rcu_read_unlock();
    if (view->failcache != NULL) {
      dns_badcache_flushname(view->failcache, name);
    }
  }

  if (view->cache != NULL) {
    result = dns_cache_flushnode(view->cache, name, tree);
  }

  return result;
}

isc_result_t
dns_view_freezezones(dns_view_t *view, bool value) {
  isc_result_t result;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_freezezones(zonetable, view, value);
  } else {
    result = ISC_R_SUCCESS;
  }
  rcu_read_unlock();

  return result;
}

void
dns_view_initntatable(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));
  if (view->ntatable_priv != NULL) {
    dns_ntatable_detach(&view->ntatable_priv);
  }
  dns_ntatable_create(view, &view->ntatable_priv);
}

isc_result_t
dns_view_getntatable(dns_view_t *view, dns_ntatable_t **ntp) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(ntp != NULL && *ntp == NULL);
  if (view->ntatable_priv == NULL) {
    return ISC_R_NOTFOUND;
  }
  dns_ntatable_attach(view->ntatable_priv, ntp);
  return ISC_R_SUCCESS;
}

void
dns_view_initsecroots(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));
  if (view->secroots_priv != NULL) {
    dns_keytable_detach(&view->secroots_priv);
  }
  dns_keytable_create(view, &view->secroots_priv);
}

isc_result_t
dns_view_getsecroots(dns_view_t *view, dns_keytable_t **ktp) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(ktp != NULL && *ktp == NULL);
  if (view->secroots_priv == NULL) {
    return ISC_R_NOTFOUND;
  }
  dns_keytable_attach(view->secroots_priv, ktp);
  return ISC_R_SUCCESS;
}

bool
dns_view_ntacovers(dns_view_t *view, isc_stdtime_t now, const dns_name_t *name,
       const dns_name_t *anchor) {
  REQUIRE(DNS_VIEW_VALID(view));

  if (view->ntatable_priv == NULL) {
    return false;
  }

  return dns_ntatable_covered(view->ntatable_priv, now, name, anchor);
}

bool
dns_view_issecuredomain(dns_view_t *view, const dns_name_t *name,
      isc_stdtime_t now, bool checknta, bool *ntap) {
  bool secure = false;
  dns_fixedname_t fn;
  dns_name_t *anchor;

  REQUIRE(DNS_VIEW_VALID(view));

  if (!view->enablevalidation || view->secroots_priv == NULL) {
    return false;
  }

  anchor = dns_fixedname_initname(&fn);
  secure = dns_keytable_issecuredomain(view->secroots_priv, name, anchor);

  SET_IF_NOT_NULL(ntap, false);
  if (checknta && secure && view->ntatable_priv != NULL &&
      dns_ntatable_covered(view->ntatable_priv, now, name, anchor))
  {
    SET_IF_NOT_NULL(ntap, true);
    secure = false;
  }

  return secure;
}

void
dns_view_untrust(dns_view_t *view, const dns_name_t *keyname,
     const dns_rdata_dnskey_t *dnskey) {
  isc_result_t result;
  dns_keytable_t *sr = NULL;
  dns_rdata_dnskey_t tmpkey;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(keyname != NULL);
  REQUIRE(dnskey != NULL);

  result = dns_view_getsecroots(view, &sr);
  if (result != ISC_R_SUCCESS) {
    return;
  }

  /*
   * Clear the revoke bit, if set, so that the key will match what's
   * in secroots now.
   */
  tmpkey = *dnskey;
  tmpkey.flags &= ~DNS_KEYFLAG_REVOKE;

  result = dns_keytable_deletekey(sr, keyname, &tmpkey);
  if (result == ISC_R_SUCCESS) {
    /*
     * If key was found in secroots, then it was a
     * configured trust anchor, and we want to fail
     * secure. If there are no other configured keys,
     * then leave a null key so that we can't validate
     * anymore.
     */
    dns_keytable_marksecure(sr, keyname);
  }

  dns_keytable_detach(&sr);
}

bool
dns_view_istrusted(dns_view_t *view, const dns_name_t *keyname,
       const dns_rdata_dnskey_t *dnskey) {
  isc_result_t result;
  dns_keytable_t *sr = NULL;
  dns_keynode_t *knode = NULL;
  bool answer = false;
  dns_rdataset_t dsset;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(keyname != NULL);
  REQUIRE(dnskey != NULL);

  result = dns_view_getsecroots(view, &sr);
  if (result != ISC_R_SUCCESS) {
    return false;
  }

  dns_rdataset_init(&dsset);
  result = dns_keytable_find(sr, keyname, &knode);
  if (result == ISC_R_SUCCESS) {
    if (dns_keynode_dsset(knode, &dsset)) {
      dns_rdata_t rdata = DNS_RDATA_INIT;
      unsigned char data[DNS_RDATA_MAXLENGTH];
      unsigned char digest[DNS_DS_BUFFERSIZE];
      dns_rdata_dnskey_t tmpkey = *dnskey;
      dns_rdata_ds_t ds;
      isc_buffer_t b;
      dns_rdataclass_t rdclass = tmpkey.common.rdclass;

      /*
       * Clear the revoke bit, if set, so that the key
       * will match what's in secroots now.
       */
      tmpkey.flags &= ~DNS_KEYFLAG_REVOKE;

      isc_buffer_init(&b, data, sizeof(data));
      result = dns_rdata_fromstruct(&rdata, rdclass,
                  dns_rdatatype_dnskey,
                  &tmpkey, &b);
      if (result != ISC_R_SUCCESS) {
        goto finish;
      }

      result = dns_ds_fromkeyrdata(
        keyname, &rdata, DNS_DSDIGEST_SHA256, digest,
        sizeof(digest), &ds);
      if (result != ISC_R_SUCCESS) {
        goto finish;
      }

      dns_rdata_reset(&rdata);
      isc_buffer_init(&b, data, sizeof(data));
      result = dns_rdata_fromstruct(
        &rdata, rdclass, dns_rdatatype_ds, &ds, &b);
      if (result != ISC_R_SUCCESS) {
        goto finish;
      }

      DNS_RDATASET_FOREACH(&dsset) {
        dns_rdata_t this = DNS_RDATA_INIT;
        dns_rdataset_current(&dsset, &this);
        if (dns_rdata_compare(&rdata, &this) == 0) {
          answer = true;
          break;
        }
      }
    }
  }

finish:
  dns_rdataset_cleanup(&dsset);
  if (knode != NULL) {
    dns_keynode_detach(&knode);
  }
  dns_keytable_detach(&sr);
  return answer;
}

isc_result_t
dns_view_searchdlz(dns_view_t *view, const dns_name_t *name,
       unsigned int minlabels, dns_clientinfomethods_t *methods,
       dns_clientinfo_t *clientinfo, dns_db_t **dbp) {
  dns_fixedname_t fname;
  dns_name_t *zonename;
  unsigned int namelabels;
  unsigned int i;
  isc_result_t result;
  dns_dlzfindzone_t findzone;
  dns_db_t *db, *best = NULL;

  /*
   * Performs checks to make sure data is as we expect it to be.
   */
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(name != NULL);
  REQUIRE(dbp != NULL && *dbp == NULL);

  /* setup a "fixed" dns name */
  zonename = dns_fixedname_initname(&fname);

  /* count the number of labels in the name */
  namelabels = dns_name_countlabels(name);

  ISC_LIST_FOREACH(view->dlz_searched, dlzdb, link) {
    REQUIRE(DNS_DLZ_VALID(dlzdb));

    /*
     * loop through starting with the longest domain name and
     * trying shorter names portions of the name until we find a
     * match, have an error, or are below the 'minlabels'
     * threshold.  minlabels is 0, if neither the standard
     * database nor any previous DLZ database had a zone name
     * match. Otherwise minlabels is the number of labels
     * in that name.  We need to beat that for a "better"
     * match for this DLZ database to be authoritative.
     */
    for (i = namelabels; i > minlabels && i > 1; i--) {
      if (i == namelabels) {
        dns_name_copy(name, zonename);
      } else {
        dns_name_split(name, i, NULL, zonename);
      }

      /* ask SDLZ driver if the zone is supported */
      db = NULL;
      findzone = dlzdb->implementation->methods->findzone;
      result = (*findzone)(dlzdb->implementation->driverarg,
               dlzdb->dbdata, dlzdb->mctx,
               view->rdclass, zonename, methods,
               clientinfo, &db);

      if (result != ISC_R_NOTFOUND) {
        if (best != NULL) {
          dns_db_detach(&best);
        }
        if (result == ISC_R_SUCCESS) {
          INSIST(db != NULL);
          dns_db_attach(db, &best);
          dns_db_detach(&db);
          minlabels = i;
        } else {
          if (db != NULL) {
            dns_db_detach(&db);
          }
          break;
        }
      } else if (db != NULL) {
        dns_db_detach(&db);
      }
    }
  }

  if (best != NULL) {
    dns_db_attach(best, dbp);
    dns_db_detach(&best);
    return ISC_R_SUCCESS;
  }

  return ISC_R_NOTFOUND;
}

uint32_t
dns_view_getfailttl(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));
  return view->fail_ttl;
}

void
dns_view_setfailttl(dns_view_t *view, uint32_t fail_ttl) {
  REQUIRE(DNS_VIEW_VALID(view));
  view->fail_ttl = fail_ttl;
}

isc_result_t
dns_view_saventa(dns_view_t *view) {
  isc_result_t result;
  bool removefile = false;
  dns_ntatable_t *ntatable = NULL;
  FILE *fp = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  if (view->nta_lifetime == 0) {
    return ISC_R_SUCCESS;
  }

  /* Open NTA save file for overwrite. */
  CHECK(isc_stdio_open(view->nta_file, "w", &fp));

  result = dns_view_getntatable(view, &ntatable);
  if (result == ISC_R_NOTFOUND) {
    removefile = true;
    result = ISC_R_SUCCESS;
    goto cleanup;
  } else {
    CHECK(result);
  }

  result = dns_ntatable_save(ntatable, fp);
  if (result == ISC_R_NOTFOUND) {
    removefile = true;
    result = ISC_R_SUCCESS;
  } else if (result == ISC_R_SUCCESS) {
    result = isc_stdio_close(fp);
    fp = NULL;
  }

cleanup:
  if (ntatable != NULL) {
    dns_ntatable_detach(&ntatable);
  }

  if (fp != NULL) {
    (void)isc_stdio_close(fp);
  }

  /* Don't leave half-baked NTA save files lying around. */
  if (result != ISC_R_SUCCESS || removefile) {
    (void)isc_file_remove(view->nta_file);
  }

  return result;
}

#define TSTR(t) ((t).value.as_textregion.base)
#define TLEN(t) ((t).value.as_textregion.length)

isc_result_t
dns_view_loadnta(dns_view_t *view) {
  isc_result_t result;
  dns_ntatable_t *ntatable = NULL;
  isc_lex_t *lex = NULL;
  isc_token_t token;
  isc_stdtime_t now = isc_stdtime_now();

  REQUIRE(DNS_VIEW_VALID(view));

  if (view->nta_lifetime == 0) {
    return ISC_R_SUCCESS;
  }

  isc_lex_create(view->mctx, 1025, &lex);
  CHECK(isc_lex_openfile(lex, view->nta_file));
  CHECK(dns_view_getntatable(view, &ntatable));

  for (;;) {
    int options = (ISC_LEXOPT_EOL | ISC_LEXOPT_EOF);
    char *name, *type, *timestamp;
    size_t len;
    dns_fixedname_t fn;
    const dns_name_t *ntaname;
    isc_buffer_t b;
    isc_stdtime_t t;
    bool forced;

    CHECK(isc_lex_gettoken(lex, options, &token));
    if (token.type == isc_tokentype_eof) {
      break;
    } else if (token.type != isc_tokentype_string) {
      CLEANUP(ISC_R_UNEXPECTEDTOKEN);
    }
    name = TSTR(token);
    len = TLEN(token);

    if (strcmp(name, ".") == 0) {
      ntaname = dns_rootname;
    } else {
      dns_name_t *fname;
      fname = dns_fixedname_initname(&fn);

      isc_buffer_init(&b, name, (unsigned int)len);
      isc_buffer_add(&b, (unsigned int)len);
      CHECK(dns_name_fromtext(fname, &b, dns_rootname, 0));
      ntaname = fname;
    }

    CHECK(isc_lex_gettoken(lex, options, &token));
    if (token.type != isc_tokentype_string) {
      CLEANUP(ISC_R_UNEXPECTEDTOKEN);
    }
    type = TSTR(token);

    if (strcmp(type, "regular") == 0) {
      forced = false;
    } else if (strcmp(type, "forced") == 0) {
      forced = true;
    } else {
      CLEANUP(ISC_R_UNEXPECTEDTOKEN);
    }

    CHECK(isc_lex_gettoken(lex, options, &token));
    if (token.type != isc_tokentype_string) {
      CLEANUP(ISC_R_UNEXPECTEDTOKEN);
    }
    timestamp = TSTR(token);
    CHECK(dns_time32_fromtext(timestamp, &t));

    CHECK(isc_lex_gettoken(lex, options, &token));
    if (token.type != isc_tokentype_eol &&
        token.type != isc_tokentype_eof)
    {
      CLEANUP(ISC_R_UNEXPECTEDTOKEN);
    }

    if (now <= t) {
      if (t > (now + 604800)) {
        t = now + 604800;
      }

      (void)dns_ntatable_add(ntatable, ntaname, forced, 0, t);
    } else {
      char nb[DNS_NAME_FORMATSIZE];
      dns_name_format(ntaname, nb, sizeof(nb));
      isc_log_write(DNS_LOGCATEGORY_DNSSEC, DNS_LOGMODULE_NTA,
              ISC_LOG_INFO,
              "ignoring expired NTA at %s", nb);
    }
  }

cleanup:
  if (ntatable != NULL) {
    dns_ntatable_detach(&ntatable);
  }

  if (lex != NULL) {
    isc_lex_close(lex);
    isc_lex_destroy(&lex);
  }

  return result;
}

void
dns_view_setviewcommit(dns_view_t *view) {
  dns_zone_t *redirect = NULL, *managed_keys = NULL;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  LOCK(&view->lock);

  if (view->redirect != NULL) {
    dns_zone_attach(view->redirect, &redirect);
  }
  if (view->managed_keys != NULL) {
    dns_zone_attach(view->managed_keys, &managed_keys);
  }

  UNLOCK(&view->lock);

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    dns_zt_setviewcommit(zonetable);
  }
  rcu_read_unlock();

  if (redirect != NULL) {
    dns_zone_setviewcommit(redirect);
    dns_zone_detach(&redirect);
  }
  if (managed_keys != NULL) {
    dns_zone_setviewcommit(managed_keys);
    dns_zone_detach(&managed_keys);
  }
}

void
dns_view_setviewrevert(dns_view_t *view) {
  dns_zone_t *redirect = NULL, *managed_keys = NULL;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  /*
   * dns_zt_setviewrevert() attempts to lock this view, so we must
   * release the lock.
   */
  LOCK(&view->lock);
  if (view->redirect != NULL) {
    dns_zone_attach(view->redirect, &redirect);
  }
  if (view->managed_keys != NULL) {
    dns_zone_attach(view->managed_keys, &managed_keys);
  }
  UNLOCK(&view->lock);

  if (redirect != NULL) {
    dns_zone_setviewrevert(redirect);
    dns_zone_detach(&redirect);
  }
  if (managed_keys != NULL) {
    dns_zone_setviewrevert(managed_keys);
    dns_zone_detach(&managed_keys);
  }
  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    dns_zt_setviewrevert(zonetable);
  }
  rcu_read_unlock();
}

bool
dns_view_staleanswerenabled(dns_view_t *view) {
  uint32_t stale_ttl = 0;
  bool result = false;

  REQUIRE(DNS_VIEW_VALID(view));

  if (dns_db_getservestalettl(view->cachedb, &stale_ttl) != ISC_R_SUCCESS)
  {
    return false;
  }
  if (stale_ttl > 0) {
    if (view->staleanswersok == dns_stale_answer_yes) {
      result = true;
    } else if (view->staleanswersok == dns_stale_answer_conf) {
      result = view->staleanswersenable;
    }
  }

  return result;
}

void
dns_view_flushonshutdown(dns_view_t *view, bool flush) {
  REQUIRE(DNS_VIEW_VALID(view));

  view->flush = flush;
}

void
dns_view_sfd_add(dns_view_t *view, const dns_name_t *name) {
  isc_result_t result;

  REQUIRE(DNS_VIEW_VALID(view));

  result = dns_nametree_add(view->sfd, name, 0);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
}

void
dns_view_sfd_del(dns_view_t *view, const dns_name_t *name) {
  REQUIRE(DNS_VIEW_VALID(view));

  dns_nametree_delete(view->sfd, name);
}

void
dns_view_sfd_find(dns_view_t *view, const dns_name_t *name,
      dns_name_t *foundname) {
  REQUIRE(DNS_VIEW_VALID(view));

  if (!dns_nametree_covered(view->sfd, name, foundname, 0)) {
    dns_name_copy(dns_rootname, foundname);
  }
}

isc_result_t
dns_view_getresolver(dns_view_t *view, dns_resolver_t **resolverp) {
  isc_result_t result;
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(resolverp != NULL && *resolverp == NULL);
  LOCK(&view->lock);
  if (view->resolver != NULL) {
    dns_resolver_attach(view->resolver, resolverp);
    result = ISC_R_SUCCESS;
  } else {
    result = ISC_R_SHUTTINGDOWN;
  }
  UNLOCK(&view->lock);
  return result;
}

void
dns_view_setmaxrrperset(dns_view_t *view, uint32_t value) {
  REQUIRE(DNS_VIEW_VALID(view));
  view->maxrrperset = value;
  if (view->cache != NULL) {
    dns_cache_setmaxrrperset(view->cache, value);
  }
}

void
dns_view_setmaxtypepername(dns_view_t *view, uint32_t value) {
  REQUIRE(DNS_VIEW_VALID(view));
  view->maxtypepername = value;
  if (view->cache != NULL) {
    dns_cache_setmaxtypepername(view->cache, value);
  }
}

void
dns_view_setudpsize(dns_view_t *view, uint16_t udpsize) {
  REQUIRE(DNS_VIEW_VALID(view));
  view->udpsize = udpsize;
}

uint16_t
dns_view_getudpsize(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));
  return view->udpsize;
}

dns_dispatchmgr_t *
dns_view_getdispatchmgr(dns_view_t *view) {
  REQUIRE(DNS_VIEW_VALID(view));

  rcu_read_lock();
  dns_dispatchmgr_t *dispatchmgr = rcu_dereference(view->dispatchmgr);
  if (dispatchmgr != NULL) {
    dns_dispatchmgr_ref(dispatchmgr);
  }
  rcu_read_unlock();

  return dispatchmgr;
}

isc_result_t
dns_view_addtrustedkey(dns_view_t *view, dns_rdatatype_t rdtype,
           const dns_name_t *keyname, isc_buffer_t *databuf) {
  isc_result_t result;
  dns_name_t *name = UNCONST(keyname);
  char rdatabuf[DNS_RDATA_MAXLENGTH];
  unsigned char digest[DNS_DS_BUFFERSIZE];
  dns_rdata_ds_t ds;
  dns_rdata_t rdata;
  isc_buffer_t b;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(view->rdclass == dns_rdataclass_in);

  if (rdtype != dns_rdatatype_dnskey && rdtype != dns_rdatatype_ds) {
    CLEANUP(ISC_R_NOTIMPLEMENTED);
  }

  isc_buffer_init(&b, rdatabuf, sizeof(rdatabuf));
  dns_rdata_init(&rdata);
  isc_buffer_setactive(databuf, isc_buffer_usedlength(databuf));
  CHECK(dns_rdata_fromwire(&rdata, view->rdclass, rdtype, databuf,
         DNS_DECOMPRESS_NEVER, &b));

  if (rdtype == dns_rdatatype_ds) {
    CHECK(dns_rdata_tostruct(&rdata, &ds, NULL));
  } else {
    CHECK(dns_ds_fromkeyrdata(name, &rdata, DNS_DSDIGEST_SHA256,
            digest, sizeof(digest), &ds));
  }

  CHECK(dns_keytable_add(view->secroots_priv, false, false, name, &ds,
             NULL, NULL));

cleanup:
  return result;
}

isc_result_t
dns_view_apply(dns_view_t *view, bool stop, isc_result_t *sub,
         isc_result_t (*action)(dns_zone_t *, void *), void *uap) {
  isc_result_t result;
  dns_zt_t *zonetable = NULL;

  REQUIRE(DNS_VIEW_VALID(view));

  rcu_read_lock();
  zonetable = rcu_dereference(view->zonetable);
  if (zonetable != NULL) {
    result = dns_zt_apply(zonetable, stop, sub, action, uap);
  } else {
    result = ISC_R_SHUTTINGDOWN;
  }
  rcu_read_unlock();
  return result;
}

void
dns_view_getadb(dns_view_t *view, dns_adb_t **adbp) {
  dns_adb_t *adb = NULL;

  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(adbp != NULL && *adbp == NULL);

  rcu_read_lock();
  adb = rcu_dereference(view->adb);
  if (adb != NULL) {
    dns_adb_attach(adb, adbp);
  }
  rcu_read_unlock();
}

void
dns_view_setmaxrestarts(dns_view_t *view, uint8_t max_restarts) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(max_restarts > 0);

  view->max_restarts = max_restarts;
}

void
dns_view_setmaxqueries(dns_view_t *view, uint16_t max_queries) {
  REQUIRE(DNS_VIEW_VALID(view));
  REQUIRE(max_queries > 0);

  view->max_queries = max_queries;
}

isc_result_t
dns_view_setmaxdelegationservers(dns_view_t *view, uint32_t max_servers) {
  REQUIRE(DNS_VIEW_VALID(view));

  if (max_servers < 1 || max_servers > MAX_DELEGATION_SERVERS) {
    return ISC_R_RANGE;
  }

  view->max_delegation_servers = max_servers;

  return ISC_R_SUCCESS;
}

Coverage Report

Created: 2026-08-31 07:21