/src/bind9/lib/dns/db.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 */

/***
 *** Imports
 ***/

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

#include <isc/buffer.h>
#include <isc/hash.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/result.h>
#include <isc/rwlock.h>
#include <isc/string.h>
#include <isc/tid.h>
#include <isc/urcu.h>
#include <isc/util.h>

#include <dns/callbacks.h>
#include <dns/clientinfo.h>
#include <dns/db.h>
#include <dns/master.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>

/***
 *** Private Types
 ***/

struct dns_dbimplementation {
  const char *name;
  dns_dbcreatefunc_t create;
  isc_mem_t *mctx;
  void *driverarg;
  ISC_LINK(dns_dbimplementation_t) link;
};

/***
 *** Supported DB Implementations Registry
 ***/

/*
 * Built in database implementations are registered here.
 */

#include "db_p.h"
#include "qpcache_p.h"
#include "qpzone_p.h"

unsigned int dns_pps = 0U;

static ISC_LIST(dns_dbimplementation_t) implementations;
static isc_rwlock_t implock;

static dns_dbimplementation_t qpimp;
static dns_dbimplementation_t qpzoneimp;

void
dns__db_initialize(void) {
  isc_rwlock_init(&implock);

  ISC_LIST_INIT(implementations);

  qpimp = (dns_dbimplementation_t){
    .name = "qpcache",
    .create = dns__qpcache_create,
    .link = ISC_LINK_INITIALIZER,
  };

  qpzoneimp = (dns_dbimplementation_t){
    .name = "qpzone",
    .create = dns__qpzone_create,
    .link = ISC_LINK_INITIALIZER,
  };

  ISC_LIST_APPEND(implementations, &qpimp, link);
  ISC_LIST_APPEND(implementations, &qpzoneimp, link);
}

void
dns__db_shutdown(void) {
  isc_rwlock_destroy(&implock);
}

static dns_dbimplementation_t *
impfind(const char *name) {
  ISC_LIST_FOREACH(implementations, imp, link) {
    if (strcasecmp(name, imp->name) == 0) {
      return imp;
    }
  }
  return NULL;
}

static void
call_updatenotify(dns_db_t *db);

/***
 *** Basic DB Methods
 ***/

isc_result_t
dns_db_create(isc_mem_t *mctx, const char *db_type, const dns_name_t *origin,
        dns_dbtype_t type, dns_rdataclass_t rdclass, unsigned int argc,
        char *argv[], dns_db_t **dbp) {
  dns_dbimplementation_t *impinfo = NULL;

  /*
   * Create a new database using implementation 'db_type'.
   */

  REQUIRE(dbp != NULL && *dbp == NULL);
  REQUIRE(dns_name_isabsolute(origin));

  RWLOCK(&implock, isc_rwlocktype_read);
  impinfo = impfind(db_type);
  if (impinfo != NULL) {
    isc_result_t result;
    result = ((impinfo->create)(mctx, origin, type, rdclass, argc,
              argv, impinfo->driverarg, dbp));
    RWUNLOCK(&implock, isc_rwlocktype_read);

#if DNS_DB_TRACE
    fprintf(stderr, "dns_db_create:%s:%s:%d:%p->references = 1\n",
      __func__, __FILE__, __LINE__ + 1, *dbp);
#endif
    return result;
  }

  RWUNLOCK(&implock, isc_rwlocktype_read);

  isc_log_write(DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DB, ISC_LOG_ERROR,
          "unsupported database type '%s'", db_type);

  return ISC_R_NOTFOUND;
}

static void
dns__db_destroy(dns_db_t *db) {
  (db->methods->destroy)(db);
}

#if DNS_DB_TRACE
ISC_REFCOUNT_TRACE_IMPL(dns_db, dns__db_destroy);
#else
ISC_REFCOUNT_IMPL(dns_db, dns__db_destroy);
#endif

bool
dns_db_iscache(dns_db_t *db) {
  /*
   * Does 'db' have cache semantics?
   */

  REQUIRE(DNS_DB_VALID(db));

  if ((db->attributes & DNS_DBATTR_CACHE) != 0) {
    return true;
  }

  return false;
}

bool
dns_db_iszone(dns_db_t *db) {
  /*
   * Does 'db' have zone semantics?
   */

  REQUIRE(DNS_DB_VALID(db));

  if ((db->attributes & (DNS_DBATTR_CACHE | DNS_DBATTR_STUB)) == 0) {
    return true;
  }

  return false;
}

bool
dns_db_isstub(dns_db_t *db) {
  /*
   * Does 'db' have stub semantics?
   */

  REQUIRE(DNS_DB_VALID(db));

  if ((db->attributes & DNS_DBATTR_STUB) != 0) {
    return true;
  }

  return false;
}

bool
dns_db_issecure(dns_db_t *db) {
  /*
   * Is 'db' secure?
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);

  if (db->methods->issecure != NULL) {
    return (db->methods->issecure)(db);
  }
  return false;
}

bool
dns_db_ispersistent(dns_db_t *db) {
  /*
   * Is 'db' persistent?
   */

  REQUIRE(DNS_DB_VALID(db));

  if (db->methods->beginload == NULL) {
    /* If the database can't be loaded, assume it's persistent */
    return true;
  }

  return false;
}

dns_name_t *
dns_db_origin(dns_db_t *db) {
  /*
   * The origin of the database.
   */

  REQUIRE(DNS_DB_VALID(db));

  return &db->origin;
}

dns_rdataclass_t
dns_db_class(dns_db_t *db) {
  /*
   * The class of the database.
   */

  REQUIRE(DNS_DB_VALID(db));

  return db->rdclass;
}

isc_result_t
dns_db_beginload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
  /*
   * Begin loading 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(DNS_CALLBACK_VALID(callbacks));

  if (db->methods->beginload != NULL) {
    return (db->methods->beginload)(db, callbacks);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_endload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
  /*
   * Finish loading 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(DNS_CALLBACK_VALID(callbacks));
  REQUIRE(callbacks->add_private != NULL);

  /*
   * When dns_db_endload() is called, we call the onupdate function
   * for all registered listeners, regardless of whether the underlying
   * database has an 'endload' implementation.
   */
  call_updatenotify(db);

  if (db->methods->endload != NULL) {
    return (db->methods->endload)(db, callbacks);
  }

  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_beginupdate(dns_db_t *db, dns_dbversion_t *ver,
       dns_rdatacallbacks_t *callbacks) {
  /*
   * Begin updating 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(dns_db_iszone(db));
  REQUIRE(DNS_CALLBACK_VALID(callbacks));

  if (db->methods->beginupdate != NULL) {
    return (db->methods->beginupdate)(db, ver, callbacks);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_commitupdate(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
  /*
   * Commit the update to 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(dns_db_iszone(db));
  REQUIRE(DNS_CALLBACK_VALID(callbacks));

  if (db->methods->commitupdate != NULL) {
    return (db->methods->commitupdate)(db, callbacks);
  }

  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_abortupdate(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
  /*
   * Abort the update to 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(dns_db_iszone(db));
  REQUIRE(DNS_CALLBACK_VALID(callbacks));

  if (db->methods->abortupdate != NULL) {
    return (db->methods->abortupdate)(db, callbacks);
  }

  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_load(dns_db_t *db, const char *filename, dns_masterformat_t format,
      unsigned int options) {
  isc_result_t result, eresult;
  dns_rdatacallbacks_t callbacks;

  /*
   * Load master file 'filename' into 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));

  if ((db->attributes & DNS_DBATTR_CACHE) != 0) {
    options |= DNS_MASTER_AGETTL;
  }

  dns_rdatacallbacks_init(&callbacks);
  RETERR(dns_db_beginload(db, &callbacks));
  result = dns_master_loadfile(filename, &db->origin, &db->origin,
             db->rdclass, options, 0, &callbacks, NULL,
             NULL, db->mctx, format, 0);
  eresult = dns_db_endload(db, &callbacks);
  /*
   * We always call dns_db_endload(), but we only want to return its
   * result if dns_master_loadfile() succeeded.  If dns_master_loadfile()
   * failed, we want to return the result code it gave us.
   */
  if (eresult != ISC_R_SUCCESS &&
      (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE))
  {
    result = eresult;
  }

  return result;
}

/***
 *** Version Methods
 ***/

void
dns_db_currentversion(dns_db_t *db, dns_dbversion_t **versionp) {
  /*
   * Open the current version for reading.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
  REQUIRE(versionp != NULL && *versionp == NULL);

  (db->methods->currentversion)(db, versionp);
}

isc_result_t
dns_db_newversion(dns_db_t *db, dns_dbversion_t **versionp) {
  /*
   * Open a new version for reading and writing.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
  REQUIRE(versionp != NULL && *versionp == NULL);

  if (db->methods->newversion != NULL) {
    return (db->methods->newversion)(db, versionp);
  }
  return ISC_R_NOTIMPLEMENTED;
}

void
dns_db_attachversion(dns_db_t *db, dns_dbversion_t *source,
         dns_dbversion_t **targetp) {
  /*
   * Attach '*targetp' to 'source'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
  REQUIRE(source != NULL);
  REQUIRE(targetp != NULL && *targetp == NULL);

  (db->methods->attachversion)(db, source, targetp);

  ENSURE(*targetp != NULL);
}

void
dns__db_closeversion(dns_db_t *db, dns_dbversion_t **versionp,
         bool commit DNS__DB_FLARG) {
  /*
   * Close version '*versionp'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
  REQUIRE(versionp != NULL && *versionp != NULL);

  (db->methods->closeversion)(db, versionp, commit DNS__DB_FLARG_PASS);

  if (commit) {
    call_updatenotify(db);
  }

  ENSURE(*versionp == NULL);
}

/***
 *** Node Methods
 ***/

isc_result_t
dns__db_findnode(dns_db_t *db, const dns_name_t *name, bool create,
     dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo,
     dns_dbnode_t **nodep DNS__DB_FLARG) {
  /*
   * Find the node with name 'name', passing 'arg' to the database
   * implementation.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(nodep != NULL && *nodep == NULL);

  if (db->methods->findnode != NULL) {
    return (db->methods->findnode)(db, name, create, methods,
                 clientinfo,
                 nodep DNS__DB_FLARG_PASS);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns__db_findnsec3node(dns_db_t *db, const dns_name_t *name, bool create,
          dns_dbnode_t **nodep DNS__DB_FLARG) {
  /*
   * Find the node with name 'name'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(nodep != NULL && *nodep == NULL);

  return (db->methods->findnsec3node)(db, name, create,
              nodep DNS__DB_FLARG_PASS);
}

isc_result_t
dns__db_find(dns_db_t *db, const dns_name_t *name, dns_dbversion_t *version,
       dns_rdatatype_t type, unsigned int options, isc_stdtime_t now,
       dns_name_t *foundname, dns_clientinfomethods_t *methods,
       dns_clientinfo_t *clientinfo, dns_rdataset_t *rdataset,
       dns_rdataset_t *sigrdataset DNS__DB_FLARG) {
  /*
   * Find the best match for 'name' and 'type' in version 'version'
   * of 'db', passing in 'arg'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(type != dns_rdatatype_rrsig);
  REQUIRE(dns_name_hasbuffer(foundname));
  REQUIRE(rdataset == NULL || (DNS_RDATASET_VALID(rdataset) &&
             !dns_rdataset_isassociated(rdataset)));
  REQUIRE(sigrdataset == NULL ||
    (DNS_RDATASET_VALID(sigrdataset) &&
     !dns_rdataset_isassociated(sigrdataset)));

  if (db->methods->find != NULL) {
    return (db->methods->find)(db, name, version, type, options,
             now, foundname, methods, clientinfo,
             rdataset,
             sigrdataset DNS__DB_FLARG_PASS);
  }
  return ISC_R_NOTIMPLEMENTED;
}

void
dns__db_attachnode(dns_dbnode_t *source, dns_dbnode_t **targetp DNS__DB_FLARG) {
  /*
   * Attach *targetp to source.
   */

  REQUIRE(source != NULL);
  REQUIRE(targetp != NULL && *targetp == NULL);
  REQUIRE(source->methods != NULL && source->methods->attachnode != NULL);

  (source->methods->attachnode)(source, targetp DNS__DB_FLARG_PASS);
}

void
dns__db_detachnode(dns_dbnode_t **nodep DNS__DB_FLARG) {
  /*
   * Detach *nodep from its node.
   */

  REQUIRE(nodep != NULL && *nodep != NULL);
  dns_dbnode_t *node = *nodep;
  REQUIRE(node->methods != NULL && node->methods->detachnode != NULL);

  (node->methods->detachnode)(nodep DNS__DB_FLARG_PASS);

  ENSURE(*nodep == NULL);
}

void
dns_db_transfernode(dns_db_t *db, dns_dbnode_t **sourcep,
        dns_dbnode_t **targetp) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(targetp != NULL && *targetp == NULL);
  REQUIRE(sourcep != NULL && *sourcep != NULL);

  *targetp = *sourcep;
  *sourcep = NULL;
}

/***
 *** DB Iterator Creation
 ***/

isc_result_t
dns_db_createiterator(dns_db_t *db, unsigned int flags,
          dns_dbiterator_t **iteratorp) {
  /*
   * Create an iterator for version 'version' of 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(iteratorp != NULL && *iteratorp == NULL);
  REQUIRE((flags & (DNS_DB_NSEC3ONLY | DNS_DB_NONSEC3)) !=
    (DNS_DB_NSEC3ONLY | DNS_DB_NONSEC3));

  if (db->methods->createiterator != NULL) {
    return db->methods->createiterator(db, flags, iteratorp);
  }
  return ISC_R_NOTIMPLEMENTED;
}

/***
 *** Rdataset Methods
 ***/

isc_result_t
dns__db_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
         dns_rdatatype_t type, dns_rdatatype_t covers,
         isc_stdtime_t now, dns_rdataset_t *rdataset,
         dns_rdataset_t *sigrdataset DNS__DB_FLARG) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(node != NULL);
  REQUIRE(DNS_RDATASET_VALID(rdataset));
  REQUIRE(!dns_rdataset_isassociated(rdataset));
  REQUIRE(covers == dns_rdatatype_none || dns_rdatatype_issig(type));
  REQUIRE(type != dns_rdatatype_any);
  REQUIRE(sigrdataset == NULL ||
    (DNS_RDATASET_VALID(sigrdataset) &&
     !dns_rdataset_isassociated(sigrdataset)));

  return (db->methods->findrdataset)(db, node, version, type, covers, now,
             rdataset,
             sigrdataset DNS__DB_FLARG_PASS);
}

isc_result_t
dns__db_allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
         unsigned int options, isc_stdtime_t now,
         dns_rdatasetiter_t **iteratorp DNS__DB_FLARG) {
  /*
   * Make '*iteratorp' an rdataset iteratator for all rdatasets at
   * 'node' in version 'version' of 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(iteratorp != NULL && *iteratorp == NULL);

  return (db->methods->allrdatasets)(db, node, version, options, now,
             iteratorp DNS__DB_FLARG_PASS);
}

isc_result_t
dns__db_addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
        isc_stdtime_t now, dns_rdataset_t *rdataset,
        unsigned int options,
        dns_rdataset_t *addedrdataset DNS__DB_FLARG) {
  /*
   * Add 'rdataset' to 'node' in version 'version' of 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(node != NULL);
  REQUIRE(((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL) ||
    ((db->attributes & DNS_DBATTR_CACHE) != 0 && version == NULL &&
     (options & DNS_DBADD_MERGE) == 0));
  REQUIRE((options & DNS_DBADD_EXACT) == 0 ||
    (options & DNS_DBADD_MERGE) != 0);
  REQUIRE(DNS_RDATASET_VALID(rdataset));
  REQUIRE(dns_rdataset_isassociated(rdataset));
  REQUIRE(rdataset->rdclass == db->rdclass);
  REQUIRE(addedrdataset == NULL ||
    (DNS_RDATASET_VALID(addedrdataset) &&
     !dns_rdataset_isassociated(addedrdataset)));

  if (db->methods->addrdataset != NULL) {
    return (db->methods->addrdataset)(
      db, node, version, now, rdataset, options,
      addedrdataset DNS__DB_FLARG_PASS);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns__db_subtractrdataset(dns_db_t *db, dns_dbnode_t *node,
       dns_dbversion_t *version, dns_rdataset_t *rdataset,
       unsigned int options,
       dns_rdataset_t *newrdataset DNS__DB_FLARG) {
  /*
   * Remove any rdata in 'rdataset' from 'node' in version 'version' of
   * 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(node != NULL);
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL);
  REQUIRE(DNS_RDATASET_VALID(rdataset));
  REQUIRE(dns_rdataset_isassociated(rdataset));
  REQUIRE(rdataset->rdclass == db->rdclass);
  REQUIRE(newrdataset == NULL ||
    (DNS_RDATASET_VALID(newrdataset) &&
     !dns_rdataset_isassociated(newrdataset)));

  if (db->methods->subtractrdataset != NULL) {
    return (db->methods->subtractrdataset)(
      db, node, version, rdataset, options,
      newrdataset DNS__DB_FLARG_PASS);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns__db_deleterdataset(dns_db_t *db, dns_dbnode_t *node,
           dns_dbversion_t *version, dns_rdatatype_t type,
           dns_rdatatype_t covers DNS__DB_FLARG) {
  /*
   * Make it so that no rdataset of type 'type' exists at 'node' in
   * version version 'version' of 'db'.
   */

  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(node != NULL);
  REQUIRE(((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL) ||
    ((db->attributes & DNS_DBATTR_CACHE) != 0 && version == NULL));

  if (db->methods->deleterdataset != NULL) {
    return (db->methods->deleterdataset)(db, node, version, type,
                 covers DNS__DB_FLARG_PASS);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_getsoaserial(dns_db_t *db, dns_dbversion_t *ver, uint32_t *serialp) {
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  dns_rdataset_t rdataset;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  isc_buffer_t buffer;

  REQUIRE(dns_db_iszone(db) || dns_db_isstub(db));

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

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(db, node, ver, dns_rdatatype_soa, 0,
             (isc_stdtime_t)0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    goto freenode;
  }

  result = dns_rdataset_first(&rdataset);
  if (result != ISC_R_SUCCESS) {
    goto freerdataset;
  }
  dns_rdataset_current(&rdataset, &rdata);
  result = dns_rdataset_next(&rdataset);
  INSIST(result == ISC_R_NOMORE);

  INSIST(rdata.length > 20);
  isc_buffer_init(&buffer, rdata.data, rdata.length);
  isc_buffer_add(&buffer, rdata.length);
  isc_buffer_forward(&buffer, rdata.length - 20);
  *serialp = isc_buffer_getuint32(&buffer);

  result = ISC_R_SUCCESS;

freerdataset:
  dns_rdataset_disassociate(&rdataset);

freenode:
  dns_db_detachnode(&node);
  return result;
}

unsigned int
dns_db_nodecount(dns_db_t *db) {
  REQUIRE(DNS_DB_VALID(db));

  if (db->methods->nodecount != NULL) {
    return (db->methods->nodecount)(db);
  }
  return 0;
}

isc_result_t
dns_db_register(const char *name, dns_dbcreatefunc_t create, void *driverarg,
    isc_mem_t *mctx, dns_dbimplementation_t **dbimp) {
  dns_dbimplementation_t *imp;

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

  RWLOCK(&implock, isc_rwlocktype_write);
  imp = impfind(name);
  if (imp != NULL) {
    RWUNLOCK(&implock, isc_rwlocktype_write);
    return ISC_R_EXISTS;
  }

  imp = isc_mem_get(mctx, sizeof(dns_dbimplementation_t));
  imp->name = name;
  imp->create = create;
  imp->mctx = NULL;
  imp->driverarg = driverarg;
  isc_mem_attach(mctx, &imp->mctx);
  ISC_LINK_INIT(imp, link);
  ISC_LIST_APPEND(implementations, imp, link);
  RWUNLOCK(&implock, isc_rwlocktype_write);

  *dbimp = imp;

  return ISC_R_SUCCESS;
}

void
dns_db_unregister(dns_dbimplementation_t **dbimp) {
  dns_dbimplementation_t *imp;

  REQUIRE(dbimp != NULL && *dbimp != NULL);

  imp = *dbimp;
  *dbimp = NULL;
  RWLOCK(&implock, isc_rwlocktype_write);
  ISC_LIST_UNLINK(implementations, imp, link);
  isc_mem_putanddetach(&imp->mctx, imp, sizeof(dns_dbimplementation_t));
  RWUNLOCK(&implock, isc_rwlocktype_write);
  ENSURE(*dbimp == NULL);
}

isc_result_t
dns__db_getoriginnode(dns_db_t *db, dns_dbnode_t **nodep DNS__DB_FLARG) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(dns_db_iszone(db));
  REQUIRE(nodep != NULL && *nodep == NULL);

  if (db->methods->getoriginnode != NULL) {
    return (db->methods->getoriginnode)(db,
                nodep DNS__DB_FLARG_PASS);
  } else if (db->methods->findnode != NULL) {
    return (db->methods->findnode)(db, &db->origin, false, NULL,
                 NULL, nodep DNS__DB_FLARG_PASS);
  }

  return ISC_R_NOTFOUND;
}

dns_stats_t *
dns_db_getrrsetstats(dns_db_t *db) {
  REQUIRE(DNS_DB_VALID(db));

  if (db->methods->getrrsetstats != NULL) {
    return (db->methods->getrrsetstats)(db);
  }

  return NULL;
}

isc_result_t
dns_db_setcachestats(dns_db_t *db, isc_stats_t *stats) {
  REQUIRE(DNS_DB_VALID(db));

  if (db->methods->setcachestats != NULL) {
    return (db->methods->setcachestats)(db, stats);
  }

  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_getnsec3parameters(dns_db_t *db, dns_dbversion_t *version,
        dns_hash_t *hash, uint8_t *flags,
        uint16_t *iterations, unsigned char *salt,
        size_t *salt_length) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(dns_db_iszone(db));

  if (db->methods->getnsec3parameters != NULL) {
    return (db->methods->getnsec3parameters)(db, version, hash,
               flags, iterations,
               salt, salt_length);
  }

  return ISC_R_NOTFOUND;
}

isc_result_t
dns_db_getsize(dns_db_t *db, dns_dbversion_t *version, uint64_t *records,
         uint64_t *bytes) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE(dns_db_iszone(db));

  if (db->methods->getsize != NULL) {
    return (db->methods->getsize)(db, version, records, bytes);
  }

  return ISC_R_NOTFOUND;
}

isc_result_t
dns_db_setsigningtime(dns_db_t *db, dns_dbnode_t *node,
          dns_rdataset_t *rdataset, isc_stdtime_t resign) {
  if (db->methods->setsigningtime != NULL) {
    return (db->methods->setsigningtime)(db, node, rdataset,
                 resign);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_getsigningtime(dns_db_t *db, isc_stdtime_t *resign, dns_name_t *name,
          dns_typepair_t *typepair) {
  if (db->methods->getsigningtime != NULL) {
    return (db->methods->getsigningtime)(db, resign, name,
                 typepair);
  }
  return ISC_R_NOTFOUND;
}

static void
call_updatenotify(dns_db_t *db) {
  rcu_read_lock();
  struct cds_lfht *update_listeners =
    rcu_dereference(db->update_listeners);
  if (update_listeners != NULL) {
    struct cds_lfht_iter iter;
    dns_dbonupdatelistener_t *listener;
    cds_lfht_for_each_entry(update_listeners, &iter, listener,
          ht_node) {
      if (!cds_lfht_is_node_deleted(&listener->ht_node)) {
        listener->onupdate(db, listener->onupdate_arg);
      }
    }
  }
  rcu_read_unlock();
}

static void
updatenotify_free(struct rcu_head *rcu_head) {
  dns_dbonupdatelistener_t *listener =
    caa_container_of(rcu_head, dns_dbonupdatelistener_t, rcu_head);
  isc_mem_putanddetach(&listener->mctx, listener, sizeof(*listener));
}

static int
updatenotify_match(struct cds_lfht_node *ht_node, const void *_key) {
  const dns_dbonupdatelistener_t *listener =
    caa_container_of(ht_node, dns_dbonupdatelistener_t, ht_node);
  const dns_dbonupdatelistener_t *key = _key;

  return listener->onupdate == key->onupdate &&
         listener->onupdate_arg == key->onupdate_arg;
}

/*
 * Attach a notify-on-update function the database
 */
void
dns_db_updatenotify_register(dns_db_t *db, dns_dbupdate_callback_t fn,
           void *fn_arg) {
  REQUIRE(db != NULL);
  REQUIRE(fn != NULL);

  dns_dbonupdatelistener_t key = { .onupdate = fn,
           .onupdate_arg = fn_arg };
  uint32_t hash = isc_hash32(&key, sizeof(key), true);
  dns_dbonupdatelistener_t *listener = isc_mem_get(db->mctx,
               sizeof(*listener));
  *listener = key;

  isc_mem_attach(db->mctx, &listener->mctx);

  rcu_read_lock();
  struct cds_lfht *update_listeners =
    rcu_dereference(db->update_listeners);
  INSIST(update_listeners != NULL);
  struct cds_lfht_node *ht_node =
    cds_lfht_add_unique(update_listeners, hash, updatenotify_match,
            &key, &listener->ht_node);
  rcu_read_unlock();

  if (ht_node != &listener->ht_node) {
    updatenotify_free(&listener->rcu_head);
  }
}

void
dns_db_updatenotify_unregister(dns_db_t *db, dns_dbupdate_callback_t fn,
             void *fn_arg) {
  REQUIRE(db != NULL);

  dns_dbonupdatelistener_t key = { .onupdate = fn,
           .onupdate_arg = fn_arg };
  uint32_t hash = isc_hash32(&key, sizeof(key), true);
  struct cds_lfht_iter iter;

  rcu_read_lock();
  struct cds_lfht *update_listeners =
    rcu_dereference(db->update_listeners);
  INSIST(update_listeners != NULL);
  cds_lfht_lookup(update_listeners, hash, updatenotify_match, &key,
      &iter);

  struct cds_lfht_node *ht_node = cds_lfht_iter_get_node(&iter);
  if (ht_node != NULL && !cds_lfht_del(update_listeners, ht_node)) {
    dns_dbonupdatelistener_t *listener = caa_container_of(
      ht_node, dns_dbonupdatelistener_t, ht_node);
    call_rcu(&listener->rcu_head, updatenotify_free);
  }
  rcu_read_unlock();
}

isc_result_t
dns_db_setservestalettl(dns_db_t *db, dns_ttl_t ttl) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);

  if (db->methods->setservestalettl != NULL) {
    return (db->methods->setservestalettl)(db, ttl);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_getservestalettl(dns_db_t *db, dns_ttl_t *ttl) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);

  if (db->methods->getservestalettl != NULL) {
    return (db->methods->getservestalettl)(db, ttl);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_setservestalerefresh(dns_db_t *db, uint32_t interval) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);

  if (db->methods->setservestalerefresh != NULL) {
    return (db->methods->setservestalerefresh)(db, interval);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_getservestalerefresh(dns_db_t *db, uint32_t *interval) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);

  if (db->methods->getservestalerefresh != NULL) {
    return (db->methods->getservestalerefresh)(db, interval);
  }
  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_setgluecachestats(dns_db_t *db, isc_stats_t *stats) {
  REQUIRE(dns_db_iszone(db));
  REQUIRE(stats != NULL);

  if (db->methods->setgluecachestats != NULL) {
    return (db->methods->setgluecachestats)(db, stats);
  }

  return ISC_R_NOTIMPLEMENTED;
}

isc_result_t
dns_db_addglue(dns_db_t *db, dns_dbversion_t *version,
         const dns_name_t *owner_name, dns_rdataset_t *rdataset,
         dns_message_t *msg) {
  REQUIRE(DNS_DB_VALID(db));
  REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
  REQUIRE(DNS_RDATASET_VALID(rdataset));
  REQUIRE(rdataset->methods != NULL);
  REQUIRE(rdataset->type == dns_rdatatype_ns);

  if (db->methods->addglue != NULL) {
    (db->methods->addglue)(db, version, owner_name, rdataset, msg);

    return ISC_R_SUCCESS;
  }

  return ISC_R_NOTIMPLEMENTED;
}

void
dns_db_expiredata(dns_dbnode_t *node, void *data) {
  REQUIRE(node != NULL && node->methods != NULL);
  if (node->methods->expiredata != NULL) {
    (node->methods->expiredata)(node, data);
  }
}

void
dns_db_setmaxrrperset(dns_db_t *db, uint32_t value) {
  REQUIRE(DNS_DB_VALID(db));

  if (db->methods->setmaxrrperset != NULL) {
    (db->methods->setmaxrrperset)(db, value);
  }
}

void
dns_db_setmaxtypepername(dns_db_t *db, uint32_t value) {
  REQUIRE(DNS_DB_VALID(db));

  if (db->methods->setmaxtypepername != NULL) {
    (db->methods->setmaxtypepername)(db, value);
  }
}

void
dns__db_logtoomanyrecords(dns_db_t *db, const dns_name_t *name,
        dns_rdatatype_t type, const char *op,
        uint32_t limit) {
  char namebuf[DNS_NAME_FORMATSIZE];
  char originbuf[DNS_NAME_FORMATSIZE];
  char typebuf[DNS_RDATATYPE_FORMATSIZE];
  char clsbuf[DNS_RDATACLASS_FORMATSIZE];

  dns_name_format(name, namebuf, sizeof(namebuf));
  dns_name_format(&db->origin, originbuf, sizeof(originbuf));
  dns_rdatatype_format(type, typebuf, sizeof(typebuf));
  dns_rdataclass_format(db->rdclass, clsbuf, sizeof(clsbuf));

  isc_log_write(
    DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DB, ISC_LOG_ERROR,
    "error %s '%s/%s' in '%s/%s' (%s): %s (must not exceed %u)", op,
    namebuf, typebuf, originbuf, clsbuf,
    (db->attributes & DNS_DBATTR_CACHE) != 0 ? "cache" : "zone",
    isc_result_totext(DNS_R_TOOMANYRECORDS), limit);
}

isc_result_t
dns_db_getzoneversion(dns_db_t *db, isc_buffer_t *b) {
  REQUIRE(db != NULL);
  REQUIRE(b != NULL);

  if (db->methods->getzoneversion != NULL) {
    return (db->methods->getzoneversion)(db, b);
  }
  return ISC_R_NOTIMPLEMENTED;
}

Coverage Report

Created: 2026-08-13 07:07