bind9/lib/dns/view.c

/*
 * 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/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/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);

	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->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->hints != NULL) {
		dns_db_detach(&view->hints);
	}
	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_sethints(dns_view_t *view, dns_db_t *hints) {
	REQUIRE(DNS_VIEW_VALID(view));
	REQUIRE(!view->frozen);
	REQUIRE(view->hints == NULL);
	REQUIRE(dns_db_iszone(hints));

	dns_db_attach(hints, &view->hints);
}

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_hints,
	      bool use_static_stub, dns_db_t **dbp, dns_dbnode_t **nodep,
	      dns_name_t *foundname, dns_rdataset_t *rdataset,
	      dns_rdataset_t *sigrdataset) {
	isc_result_t result;
	dns_db_t *db = NULL, *zdb = NULL;
	dns_dbnode_t *node = NULL, *znode = 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 */
	REQUIRE(nodep == NULL || *nodep == NULL);

	/*
	 * 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, &node,
			     foundname, rdataset, sigrdataset);

	if (result == DNS_R_DELEGATION || result == ISC_R_NOTFOUND) {
		dns_rdataset_cleanup(rdataset);
		dns_rdataset_cleanup(sigrdataset);
		if (node != NULL) {
			dns_db_detachnode(&node);
		}
		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);
				dns_db_attachnode(znode, &node);
				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;
	}

	if (result == ISC_R_NOTFOUND && !is_staticstub_zone && use_hints &&
	    view->hints != NULL)
	{
		dns_rdataset_cleanup(rdataset);
		dns_rdataset_cleanup(sigrdataset);
		if (db != NULL) {
			if (node != NULL) {
				dns_db_detachnode(&node);
			}
			dns_db_detach(&db);
		}
		result = dns_db_find(view->hints, name, NULL, type, options,
				     now, &node, foundname, rdataset,
				     sigrdataset);
		if (result == ISC_R_SUCCESS || result == DNS_R_GLUE) {
			/*
			 * We just used a hint.  Let the resolver know it
			 * should consider priming.
			 */
			dns_resolver_t *res = NULL;
			result = dns_view_getresolver(view, &res);
			if (result == ISC_R_SUCCESS) {
				dns_resolver_prime(res);
				dns_db_attach(view->hints, &db);
				dns_resolver_detach(&res);
				result = DNS_R_HINT;
			}
		} else if (result == DNS_R_NXRRSET) {
			dns_db_attach(view->hints, &db);
			result = DNS_R_HINTNXRRSET;
		} else if (result == DNS_R_NXDOMAIN) {
			result = ISC_R_NOTFOUND;
		}

		/*
		 * Cleanup if non-standard hints are used.
		 */
		if (db == NULL && node != NULL) {
			dns_db_detachnode(&node);
		}
	}

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

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

	if (db != NULL) {
		if (node != NULL) {
			if (nodep != NULL) {
				*nodep = node;
			} else {
				dns_db_detachnode(&node);
			}
		}
		if (dbp != NULL) {
			*dbp = db;
		} else {
			dns_db_detach(&db);
		}
	} else {
		INSIST(node == NULL);
	}

	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, bool use_hints,
		    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, use_hints, false,
			       NULL, 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
findzonecut_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_NOEXACT) != 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,
			     NULL, 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
findzonecut_cache(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) {
	isc_result_t result = DNS_R_NXDOMAIN;

	if (view->cachedb != NULL) {
		result = dns_db_findzonecut(view->cachedb, name, options, now,
					    NULL, fname, dcname, rdataset,
					    NULL);
	}

	/*
	 * 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) {
		dns_rdataset_cleanup(rdataset);
		result = DNS_R_NXDOMAIN;
	}

	return result;
}

static void
findzonecut_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) {
	isc_result_t result;
	dns_rdataset_t crdataset = DNS_RDATASET_INIT;
	dns_fixedname_t f, dc;
	dns_name_t *cfname = dns_fixedname_initname(&f);
	dns_name_t *cdcname = dns_fixedname_initname(&dc);

	CHECK(findzonecut_cache(view, name, cfname, cdcname, now, options,
				&crdataset));

	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_rdataset_clone(&crdataset, rdataset);

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

cleanup:
	dns_rdataset_cleanup(&crdataset);
}

static isc_result_t
findzonecut_hints(dns_view_t *view, dns_name_t *fname, dns_name_t *dcname,
		  isc_stdtime_t now, dns_rdataset_t *rdataset) {
	isc_result_t result = ISC_R_NOTFOUND;

	if (view->hints == NULL) {
		return result;
	}

	result = dns_db_find(view->hints, dns_rootname, NULL, dns_rdatatype_ns,
			     0, now, NULL, fname, rdataset, NULL);
	if (result != ISC_R_SUCCESS) {
		dns_rdataset_cleanup(rdataset);
	} else if (dcname != NULL) {
		dns_name_copy(fname, dcname);
	}

	return result;
}

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_rdataset_t *rdataset) {
	isc_result_t result;

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

	result = findzonecut_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 = findzonecut_cache(view, name, fname, dcname, now,
					   options, rdataset);
	} else if (result == ISC_R_SUCCESS && usecache) {
		/*
		 * A zone with a (possibly partial) delegation match but the
		 * cache can have a more precise delegation.
		 */
		findzonecut_zoneorcache(view, name, fname, dcname, now, options,
					rdataset);
	}

	/*
	 * No local zone nor cache match. Last attempt with the hints.
	 */
	if (result == DNS_R_NXDOMAIN && usehints) {
		result = findzonecut_hints(view, fname, dcname, now, rdataset);
	}

	if (result != ISC_R_SUCCESS) {
		result = DNS_R_NXDOMAIN;
		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[4096], 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[DST_KEY_MAXSIZE];
	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;
}