Adding upstream version 1:9.18.19.upstream/1%9.18.19upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1598 insertions, 0 deletions

diff --git a/lib/dns/sdb.c b/lib/dns/sdb.c
new file mode 100644
index 0000000..317eeb0
--- /dev/null
+++ b/lib/dns/sdb.c
@@ -0,0 +1,1598 @@
+/*
+ * 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 <stdbool.h>
+#include <string.h>
+
+#include <isc/buffer.h>
+#include <isc/lex.h>
+#include <isc/log.h>
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/once.h>
+#include <isc/print.h>
+#include <isc/refcount.h>
+#include <isc/region.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/callbacks.h>
+#include <dns/db.h>
+#include <dns/dbiterator.h>
+#include <dns/fixedname.h>
+#include <dns/log.h>
+#include <dns/rdata.h>
+#include <dns/rdatalist.h>
+#include <dns/rdataset.h>
+#include <dns/rdatasetiter.h>
+#include <dns/rdatatype.h>
+#include <dns/sdb.h>
+#include <dns/types.h>
+
+#include "rdatalist_p.h"
+
+struct dns_sdbimplementation {
+	const dns_sdbmethods_t *methods;
+	void *driverdata;
+	unsigned int flags;
+	isc_mem_t *mctx;
+	isc_mutex_t driverlock;
+	dns_dbimplementation_t *dbimp;
+};
+
+struct dns_sdb {
+	/* Unlocked */
+	dns_db_t common;
+	char *zone;
+	dns_sdbimplementation_t *implementation;
+	void *dbdata;
+
+	/* Atomic */
+	isc_refcount_t references;
+};
+
+struct dns_sdblookup {
+	/* Unlocked */
+	unsigned int magic;
+	dns_sdb_t *sdb;
+	ISC_LIST(dns_rdatalist_t) lists;
+	ISC_LIST(isc_buffer_t) buffers;
+	dns_name_t *name;
+	ISC_LINK(dns_sdblookup_t) link;
+	dns_rdatacallbacks_t callbacks;
+
+	/* Atomic */
+	isc_refcount_t references;
+};
+
+typedef struct dns_sdblookup dns_sdbnode_t;
+
+struct dns_sdballnodes {
+	dns_dbiterator_t common;
+	ISC_LIST(dns_sdbnode_t) nodelist;
+	dns_sdbnode_t *current;
+	dns_sdbnode_t *origin;
+};
+
+typedef dns_sdballnodes_t sdb_dbiterator_t;
+
+typedef struct sdb_rdatasetiter {
+	dns_rdatasetiter_t common;
+	dns_rdatalist_t *current;
+} sdb_rdatasetiter_t;
+
+#define SDB_MAGIC ISC_MAGIC('S', 'D', 'B', '-')
+
+/*%
+ * Note that "impmagic" is not the first four bytes of the struct, so
+ * ISC_MAGIC_VALID cannot be used.
+ */
+#define VALID_SDB(sdb) ((sdb) != NULL && (sdb)->common.impmagic == SDB_MAGIC)
+
+#define SDBLOOKUP_MAGIC	      ISC_MAGIC('S', 'D', 'B', 'L')
+#define VALID_SDBLOOKUP(sdbl) ISC_MAGIC_VALID(sdbl, SDBLOOKUP_MAGIC)
+#define VALID_SDBNODE(sdbn)   VALID_SDBLOOKUP(sdbn)
+
+/* These values are taken from RFC1537 */
+#define SDB_DEFAULT_REFRESH 28800U  /* 8 hours */
+#define SDB_DEFAULT_RETRY   7200U   /* 2 hours */
+#define SDB_DEFAULT_EXPIRE  604800U /* 7 days */
+#define SDB_DEFAULT_MINIMUM 86400U  /* 1 day */
+
+/* This is a reasonable value */
+#define SDB_DEFAULT_TTL (60 * 60 * 24)
+
+#ifdef __COVERITY__
+#define MAYBE_LOCK(sdb)	  LOCK(&sdb->implementation->driverlock)
+#define MAYBE_UNLOCK(sdb) UNLOCK(&sdb->implementation->driverlock)
+#else /* ifdef __COVERITY__ */
+#define MAYBE_LOCK(sdb)                                          \
+	do {                                                     \
+		unsigned int flags = sdb->implementation->flags; \
+		if ((flags & DNS_SDBFLAG_THREADSAFE) == 0)       \
+			LOCK(&sdb->implementation->driverlock);  \
+	} while (0)
+
+#define MAYBE_UNLOCK(sdb)                                         \
+	do {                                                      \
+		unsigned int flags = sdb->implementation->flags;  \
+		if ((flags & DNS_SDBFLAG_THREADSAFE) == 0)        \
+			UNLOCK(&sdb->implementation->driverlock); \
+	} while (0)
+#endif /* ifdef __COVERITY__ */
+
+static int dummy;
+
+static isc_result_t
+dns_sdb_create(isc_mem_t *mctx, const dns_name_t *origin, dns_dbtype_t type,
+	       dns_rdataclass_t rdclass, unsigned int argc, char *argv[],
+	       void *driverarg, dns_db_t **dbp);
+
+static isc_result_t
+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);
+
+static isc_result_t
+createnode(dns_sdb_t *sdb, dns_sdbnode_t **nodep);
+
+static void
+destroynode(dns_sdbnode_t *node);
+
+static void
+detachnode(dns_db_t *db, dns_dbnode_t **targetp);
+
+static void
+list_tordataset(dns_rdatalist_t *rdatalist, dns_db_t *db, dns_dbnode_t *node,
+		dns_rdataset_t *rdataset);
+
+static void
+dbiterator_destroy(dns_dbiterator_t **iteratorp);
+static isc_result_t
+dbiterator_first(dns_dbiterator_t *iterator);
+static isc_result_t
+dbiterator_last(dns_dbiterator_t *iterator);
+static isc_result_t
+dbiterator_seek(dns_dbiterator_t *iterator, const dns_name_t *name);
+static isc_result_t
+dbiterator_prev(dns_dbiterator_t *iterator);
+static isc_result_t
+dbiterator_next(dns_dbiterator_t *iterator);
+static isc_result_t
+dbiterator_current(dns_dbiterator_t *iterator, dns_dbnode_t **nodep,
+		   dns_name_t *name);
+static isc_result_t
+dbiterator_pause(dns_dbiterator_t *iterator);
+static isc_result_t
+dbiterator_origin(dns_dbiterator_t *iterator, dns_name_t *name);
+
+static dns_dbiteratormethods_t dbiterator_methods = {
+	dbiterator_destroy, dbiterator_first, dbiterator_last,
+	dbiterator_seek,    dbiterator_prev,  dbiterator_next,
+	dbiterator_current, dbiterator_pause, dbiterator_origin
+};
+
+static void
+rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp);
+static isc_result_t
+rdatasetiter_first(dns_rdatasetiter_t *iterator);
+static isc_result_t
+rdatasetiter_next(dns_rdatasetiter_t *iterator);
+static void
+rdatasetiter_current(dns_rdatasetiter_t *iterator, dns_rdataset_t *rdataset);
+
+static dns_rdatasetitermethods_t rdatasetiter_methods = {
+	rdatasetiter_destroy, rdatasetiter_first, rdatasetiter_next,
+	rdatasetiter_current
+};
+
+/*
+ * Functions used by implementors of simple databases
+ */
+isc_result_t
+dns_sdb_register(const char *drivername, const dns_sdbmethods_t *methods,
+		 void *driverdata, unsigned int flags, isc_mem_t *mctx,
+		 dns_sdbimplementation_t **sdbimp) {
+	dns_sdbimplementation_t *imp;
+	isc_result_t result;
+
+	REQUIRE(drivername != NULL);
+	REQUIRE(methods != NULL);
+	REQUIRE(methods->lookup != NULL || methods->lookup2 != NULL);
+	REQUIRE(mctx != NULL);
+	REQUIRE(sdbimp != NULL && *sdbimp == NULL);
+	REQUIRE((flags &
+		 ~(DNS_SDBFLAG_RELATIVEOWNER | DNS_SDBFLAG_RELATIVERDATA |
+		   DNS_SDBFLAG_THREADSAFE | DNS_SDBFLAG_DNS64)) == 0);
+
+	imp = isc_mem_get(mctx, sizeof(dns_sdbimplementation_t));
+	imp->methods = methods;
+	imp->driverdata = driverdata;
+	imp->flags = flags;
+	imp->mctx = NULL;
+	isc_mem_attach(mctx, &imp->mctx);
+	isc_mutex_init(&imp->driverlock);
+
+	imp->dbimp = NULL;
+	result = dns_db_register(drivername, dns_sdb_create, imp, mctx,
+				 &imp->dbimp);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_mutex;
+	}
+	*sdbimp = imp;
+
+	return (ISC_R_SUCCESS);
+
+cleanup_mutex:
+	isc_mutex_destroy(&imp->driverlock);
+	isc_mem_put(mctx, imp, sizeof(dns_sdbimplementation_t));
+	return (result);
+}
+
+void
+dns_sdb_unregister(dns_sdbimplementation_t **sdbimp) {
+	dns_sdbimplementation_t *imp;
+
+	REQUIRE(sdbimp != NULL && *sdbimp != NULL);
+
+	imp = *sdbimp;
+	*sdbimp = NULL;
+	dns_db_unregister(&imp->dbimp);
+	isc_mutex_destroy(&imp->driverlock);
+
+	isc_mem_putanddetach(&imp->mctx, imp, sizeof(dns_sdbimplementation_t));
+}
+
+static unsigned int
+initial_size(unsigned int len) {
+	unsigned int size;
+
+	for (size = 1024; size < (64 * 1024); size *= 2) {
+		if (len < size) {
+			return (size);
+		}
+	}
+	return (65535);
+}
+
+isc_result_t
+dns_sdb_putrdata(dns_sdblookup_t *lookup, dns_rdatatype_t typeval,
+		 dns_ttl_t ttl, const unsigned char *rdatap,
+		 unsigned int rdlen) {
+	dns_rdatalist_t *rdatalist;
+	dns_rdata_t *rdata;
+	isc_buffer_t *rdatabuf = NULL;
+	isc_mem_t *mctx;
+	isc_region_t region;
+
+	mctx = lookup->sdb->common.mctx;
+
+	rdatalist = ISC_LIST_HEAD(lookup->lists);
+	while (rdatalist != NULL) {
+		if (rdatalist->type == typeval) {
+			break;
+		}
+		rdatalist = ISC_LIST_NEXT(rdatalist, link);
+	}
+
+	if (rdatalist == NULL) {
+		rdatalist = isc_mem_get(mctx, sizeof(dns_rdatalist_t));
+		dns_rdatalist_init(rdatalist);
+		rdatalist->rdclass = lookup->sdb->common.rdclass;
+		rdatalist->type = typeval;
+		rdatalist->ttl = ttl;
+		ISC_LIST_APPEND(lookup->lists, rdatalist, link);
+	} else if (rdatalist->ttl != ttl) {
+		return (DNS_R_BADTTL);
+	}
+
+	rdata = isc_mem_get(mctx, sizeof(dns_rdata_t));
+
+	isc_buffer_allocate(mctx, &rdatabuf, rdlen);
+	DE_CONST(rdatap, region.base);
+	region.length = rdlen;
+	isc_buffer_copyregion(rdatabuf, &region);
+	isc_buffer_usedregion(rdatabuf, &region);
+	dns_rdata_init(rdata);
+	dns_rdata_fromregion(rdata, rdatalist->rdclass, rdatalist->type,
+			     &region);
+	ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
+	ISC_LIST_APPEND(lookup->buffers, rdatabuf, link);
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+dns_sdb_putrr(dns_sdblookup_t *lookup, const char *type, dns_ttl_t ttl,
+	      const char *data) {
+	unsigned int datalen;
+	dns_rdatatype_t typeval;
+	isc_textregion_t r;
+	isc_lex_t *lex = NULL;
+	isc_result_t result;
+	unsigned char *p = NULL;
+	unsigned int size = 0; /* Init to suppress compiler warning */
+	isc_mem_t *mctx;
+	dns_sdbimplementation_t *imp;
+	const dns_name_t *origin;
+	isc_buffer_t b;
+	isc_buffer_t rb;
+
+	REQUIRE(VALID_SDBLOOKUP(lookup));
+	REQUIRE(type != NULL);
+	REQUIRE(data != NULL);
+
+	mctx = lookup->sdb->common.mctx;
+
+	DE_CONST(type, r.base);
+	r.length = strlen(type);
+	result = dns_rdatatype_fromtext(&typeval, &r);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	imp = lookup->sdb->implementation;
+	if ((imp->flags & DNS_SDBFLAG_RELATIVERDATA) != 0) {
+		origin = &lookup->sdb->common.origin;
+	} else {
+		origin = dns_rootname;
+	}
+
+	result = isc_lex_create(mctx, 64, &lex);
+	if (result != ISC_R_SUCCESS) {
+		goto failure;
+	}
+
+	datalen = strlen(data);
+	size = initial_size(datalen);
+	do {
+		isc_buffer_constinit(&b, data, datalen);
+		isc_buffer_add(&b, datalen);
+		result = isc_lex_openbuffer(lex, &b);
+		if (result != ISC_R_SUCCESS) {
+			goto failure;
+		}
+
+		if (size >= 65535) {
+			size = 65535;
+		}
+		p = isc_mem_get(mctx, size);
+		isc_buffer_init(&rb, p, size);
+		result = dns_rdata_fromtext(NULL, lookup->sdb->common.rdclass,
+					    typeval, lex, origin, 0, mctx, &rb,
+					    &lookup->callbacks);
+		if (result != ISC_R_NOSPACE) {
+			break;
+		}
+
+		/*
+		 * Is the RR too big?
+		 */
+		if (size >= 65535) {
+			break;
+		}
+		isc_mem_put(mctx, p, size);
+		p = NULL;
+		size *= 2;
+	} while (result == ISC_R_NOSPACE);
+
+	if (result != ISC_R_SUCCESS) {
+		goto failure;
+	}
+
+	result = dns_sdb_putrdata(lookup, typeval, ttl, isc_buffer_base(&rb),
+				  isc_buffer_usedlength(&rb));
+failure:
+	if (p != NULL) {
+		isc_mem_put(mctx, p, size);
+	}
+	if (lex != NULL) {
+		isc_lex_destroy(&lex);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+getnode(dns_sdballnodes_t *allnodes, const char *name, dns_sdbnode_t **nodep) {
+	dns_name_t *newname;
+	const dns_name_t *origin;
+	dns_fixedname_t fnewname;
+	dns_sdb_t *sdb = (dns_sdb_t *)allnodes->common.db;
+	dns_sdbimplementation_t *imp = sdb->implementation;
+	dns_sdbnode_t *sdbnode;
+	isc_mem_t *mctx = sdb->common.mctx;
+	isc_buffer_t b;
+	isc_result_t result;
+
+	newname = dns_fixedname_initname(&fnewname);
+
+	if ((imp->flags & DNS_SDBFLAG_RELATIVERDATA) != 0) {
+		origin = &sdb->common.origin;
+	} else {
+		origin = dns_rootname;
+	}
+	isc_buffer_constinit(&b, name, strlen(name));
+	isc_buffer_add(&b, strlen(name));
+
+	result = dns_name_fromtext(newname, &b, origin, 0, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	if (allnodes->common.relative_names) {
+		/* All names are relative to the root */
+		unsigned int nlabels = dns_name_countlabels(newname);
+		dns_name_getlabelsequence(newname, 0, nlabels - 1, newname);
+	}
+
+	sdbnode = ISC_LIST_HEAD(allnodes->nodelist);
+	if (sdbnode == NULL || !dns_name_equal(sdbnode->name, newname)) {
+		sdbnode = NULL;
+		result = createnode(sdb, &sdbnode);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		sdbnode->name = isc_mem_get(mctx, sizeof(dns_name_t));
+		dns_name_init(sdbnode->name, NULL);
+		dns_name_dup(newname, mctx, sdbnode->name);
+		ISC_LIST_PREPEND(allnodes->nodelist, sdbnode, link);
+		if (allnodes->origin == NULL &&
+		    dns_name_equal(newname, &sdb->common.origin))
+		{
+			allnodes->origin = sdbnode;
+		}
+	}
+	*nodep = sdbnode;
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+dns_sdb_putnamedrr(dns_sdballnodes_t *allnodes, const char *name,
+		   const char *type, dns_ttl_t ttl, const char *data) {
+	isc_result_t result;
+	dns_sdbnode_t *sdbnode = NULL;
+	result = getnode(allnodes, name, &sdbnode);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	return (dns_sdb_putrr(sdbnode, type, ttl, data));
+}
+
+isc_result_t
+dns_sdb_putnamedrdata(dns_sdballnodes_t *allnodes, const char *name,
+		      dns_rdatatype_t type, dns_ttl_t ttl, const void *rdata,
+		      unsigned int rdlen) {
+	isc_result_t result;
+	dns_sdbnode_t *sdbnode = NULL;
+	result = getnode(allnodes, name, &sdbnode);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	return (dns_sdb_putrdata(sdbnode, type, ttl, rdata, rdlen));
+}
+
+isc_result_t
+dns_sdb_putsoa(dns_sdblookup_t *lookup, const char *mname, const char *rname,
+	       uint32_t serial) {
+	char str[2 * DNS_NAME_MAXTEXT + 5 * (sizeof("2147483647")) + 7];
+	int n;
+
+	REQUIRE(mname != NULL);
+	REQUIRE(rname != NULL);
+
+	n = snprintf(str, sizeof(str), "%s %s %u %u %u %u %u", mname, rname,
+		     serial, SDB_DEFAULT_REFRESH, SDB_DEFAULT_RETRY,
+		     SDB_DEFAULT_EXPIRE, SDB_DEFAULT_MINIMUM);
+	if (n >= (int)sizeof(str) || n < 0) {
+		return (ISC_R_NOSPACE);
+	}
+	return (dns_sdb_putrr(lookup, "SOA", SDB_DEFAULT_TTL, str));
+}
+
+/*
+ * DB routines
+ */
+
+static void
+attach(dns_db_t *source, dns_db_t **targetp) {
+	dns_sdb_t *sdb = (dns_sdb_t *)source;
+
+	REQUIRE(VALID_SDB(sdb));
+
+	isc_refcount_increment(&sdb->references);
+
+	*targetp = source;
+}
+
+static void
+destroy(dns_sdb_t *sdb) {
+	dns_sdbimplementation_t *imp = sdb->implementation;
+
+	isc_refcount_destroy(&sdb->references);
+
+	if (imp->methods->destroy != NULL) {
+		MAYBE_LOCK(sdb);
+		imp->methods->destroy(sdb->zone, imp->driverdata, &sdb->dbdata);
+		MAYBE_UNLOCK(sdb);
+	}
+
+	isc_mem_free(sdb->common.mctx, sdb->zone);
+
+	sdb->common.magic = 0;
+	sdb->common.impmagic = 0;
+
+	dns_name_free(&sdb->common.origin, sdb->common.mctx);
+
+	isc_mem_putanddetach(&sdb->common.mctx, sdb, sizeof(dns_sdb_t));
+}
+
+static void
+detach(dns_db_t **dbp) {
+	dns_sdb_t *sdb = (dns_sdb_t *)(*dbp);
+
+	REQUIRE(VALID_SDB(sdb));
+
+	*dbp = NULL;
+
+	if (isc_refcount_decrement(&sdb->references) == 1) {
+		destroy(sdb);
+	}
+}
+
+static isc_result_t
+beginload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
+	UNUSED(db);
+	UNUSED(callbacks);
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static isc_result_t
+endload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
+	UNUSED(db);
+	UNUSED(callbacks);
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static isc_result_t
+dump(dns_db_t *db, dns_dbversion_t *version, const char *filename,
+     dns_masterformat_t masterformat) {
+	UNUSED(db);
+	UNUSED(version);
+	UNUSED(filename);
+	UNUSED(masterformat);
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static void
+currentversion(dns_db_t *db, dns_dbversion_t **versionp) {
+	REQUIRE(versionp != NULL && *versionp == NULL);
+
+	UNUSED(db);
+
+	*versionp = (void *)&dummy;
+	return;
+}
+
+static isc_result_t
+newversion(dns_db_t *db, dns_dbversion_t **versionp) {
+	UNUSED(db);
+	UNUSED(versionp);
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static void
+attachversion(dns_db_t *db, dns_dbversion_t *source,
+	      dns_dbversion_t **targetp) {
+	REQUIRE(source != NULL && source == (void *)&dummy);
+	REQUIRE(targetp != NULL && *targetp == NULL);
+
+	UNUSED(db);
+	*targetp = source;
+	return;
+}
+
+static void
+closeversion(dns_db_t *db, dns_dbversion_t **versionp, bool commit) {
+	REQUIRE(versionp != NULL && *versionp == (void *)&dummy);
+	REQUIRE(!commit);
+
+	UNUSED(db);
+	UNUSED(commit);
+
+	*versionp = NULL;
+}
+
+static isc_result_t
+createnode(dns_sdb_t *sdb, dns_sdbnode_t **nodep) {
+	dns_sdbnode_t *node;
+
+	node = isc_mem_get(sdb->common.mctx, sizeof(dns_sdbnode_t));
+
+	node->sdb = NULL;
+	attach((dns_db_t *)sdb, (dns_db_t **)&node->sdb);
+	ISC_LIST_INIT(node->lists);
+	ISC_LIST_INIT(node->buffers);
+	ISC_LINK_INIT(node, link);
+	node->name = NULL;
+	dns_rdatacallbacks_init(&node->callbacks);
+
+	isc_refcount_init(&node->references, 1);
+
+	node->magic = SDBLOOKUP_MAGIC;
+
+	*nodep = node;
+	return (ISC_R_SUCCESS);
+}
+
+static void
+destroynode(dns_sdbnode_t *node) {
+	dns_rdatalist_t *list;
+	dns_rdata_t *rdata;
+	isc_buffer_t *b;
+	dns_sdb_t *sdb;
+	isc_mem_t *mctx;
+
+	sdb = node->sdb;
+	mctx = sdb->common.mctx;
+
+	while (!ISC_LIST_EMPTY(node->lists)) {
+		list = ISC_LIST_HEAD(node->lists);
+		while (!ISC_LIST_EMPTY(list->rdata)) {
+			rdata = ISC_LIST_HEAD(list->rdata);
+			ISC_LIST_UNLINK(list->rdata, rdata, link);
+			isc_mem_put(mctx, rdata, sizeof(dns_rdata_t));
+		}
+		ISC_LIST_UNLINK(node->lists, list, link);
+		isc_mem_put(mctx, list, sizeof(dns_rdatalist_t));
+	}
+
+	while (!ISC_LIST_EMPTY(node->buffers)) {
+		b = ISC_LIST_HEAD(node->buffers);
+		ISC_LIST_UNLINK(node->buffers, b, link);
+		isc_buffer_free(&b);
+	}
+
+	if (node->name != NULL) {
+		dns_name_free(node->name, mctx);
+		isc_mem_put(mctx, node->name, sizeof(dns_name_t));
+	}
+
+	node->magic = 0;
+	isc_mem_put(mctx, node, sizeof(dns_sdbnode_t));
+	detach((dns_db_t **)(void *)&sdb);
+}
+
+static isc_result_t
+getoriginnode(dns_db_t *db, dns_dbnode_t **nodep) {
+	dns_sdb_t *sdb = (dns_sdb_t *)db;
+	dns_sdbnode_t *node = NULL;
+	isc_result_t result;
+	isc_buffer_t b;
+	char namestr[DNS_NAME_MAXTEXT + 1];
+	dns_sdbimplementation_t *imp;
+	dns_name_t relname;
+	dns_name_t *name;
+
+	REQUIRE(VALID_SDB(sdb));
+	REQUIRE(nodep != NULL && *nodep == NULL);
+
+	imp = sdb->implementation;
+	name = &sdb->common.origin;
+
+	if (imp->methods->lookup2 != NULL) {
+		if ((imp->flags & DNS_SDBFLAG_RELATIVEOWNER) != 0) {
+			dns_name_init(&relname, NULL);
+			name = &relname;
+		}
+	} else {
+		isc_buffer_init(&b, namestr, sizeof(namestr));
+		if ((imp->flags & DNS_SDBFLAG_RELATIVEOWNER) != 0) {
+			dns_name_init(&relname, NULL);
+			result = dns_name_totext(&relname, true, &b);
+			if (result != ISC_R_SUCCESS) {
+				return (result);
+			}
+		} else {
+			result = dns_name_totext(name, true, &b);
+			if (result != ISC_R_SUCCESS) {
+				return (result);
+			}
+		}
+		isc_buffer_putuint8(&b, 0);
+	}
+
+	result = createnode(sdb, &node);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	MAYBE_LOCK(sdb);
+	if (imp->methods->lookup2 != NULL) {
+		result = imp->methods->lookup2(&sdb->common.origin, name,
+					       sdb->dbdata, node, NULL, NULL);
+	} else {
+		result = imp->methods->lookup(sdb->zone, namestr, sdb->dbdata,
+					      node, NULL, NULL);
+	}
+	MAYBE_UNLOCK(sdb);
+	if (result != ISC_R_SUCCESS &&
+	    !(result == ISC_R_NOTFOUND && imp->methods->authority != NULL))
+	{
+		destroynode(node);
+		return (result);
+	}
+
+	if (imp->methods->authority != NULL) {
+		MAYBE_LOCK(sdb);
+		result = imp->methods->authority(sdb->zone, sdb->dbdata, node);
+		MAYBE_UNLOCK(sdb);
+		if (result != ISC_R_SUCCESS) {
+			destroynode(node);
+			return (result);
+		}
+	}
+
+	*nodep = node;
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+findnodeext(dns_db_t *db, const dns_name_t *name, bool create,
+	    dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo,
+	    dns_dbnode_t **nodep) {
+	dns_sdb_t *sdb = (dns_sdb_t *)db;
+	dns_sdbnode_t *node = NULL;
+	isc_result_t result;
+	isc_buffer_t b;
+	char namestr[DNS_NAME_MAXTEXT + 1];
+	bool isorigin;
+	dns_sdbimplementation_t *imp;
+	dns_name_t relname;
+	unsigned int labels;
+
+	REQUIRE(VALID_SDB(sdb));
+	REQUIRE(nodep != NULL && *nodep == NULL);
+
+	UNUSED(name);
+	UNUSED(create);
+
+	imp = sdb->implementation;
+
+	isorigin = dns_name_equal(name, &sdb->common.origin);
+
+	if (imp->methods->lookup2 != NULL) {
+		if ((imp->flags & DNS_SDBFLAG_RELATIVEOWNER) != 0) {
+			labels = dns_name_countlabels(name) -
+				 dns_name_countlabels(&db->origin);
+			dns_name_init(&relname, NULL);
+			dns_name_getlabelsequence(name, 0, labels, &relname);
+			name = &relname;
+		}
+	} else {
+		isc_buffer_init(&b, namestr, sizeof(namestr));
+		if ((imp->flags & DNS_SDBFLAG_RELATIVEOWNER) != 0) {
+			labels = dns_name_countlabels(name) -
+				 dns_name_countlabels(&db->origin);
+			dns_name_init(&relname, NULL);
+			dns_name_getlabelsequence(name, 0, labels, &relname);
+			result = dns_name_totext(&relname, true, &b);
+			if (result != ISC_R_SUCCESS) {
+				return (result);
+			}
+		} else {
+			result = dns_name_totext(name, true, &b);
+			if (result != ISC_R_SUCCESS) {
+				return (result);
+			}
+		}
+		isc_buffer_putuint8(&b, 0);
+	}
+
+	result = createnode(sdb, &node);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	MAYBE_LOCK(sdb);
+	if (imp->methods->lookup2 != NULL) {
+		result = imp->methods->lookup2(&sdb->common.origin, name,
+					       sdb->dbdata, node, methods,
+					       clientinfo);
+	} else {
+		result = imp->methods->lookup(sdb->zone, namestr, sdb->dbdata,
+					      node, methods, clientinfo);
+	}
+	MAYBE_UNLOCK(sdb);
+	if (result != ISC_R_SUCCESS && !(result == ISC_R_NOTFOUND && isorigin &&
+					 imp->methods->authority != NULL))
+	{
+		destroynode(node);
+		return (result);
+	}
+
+	if (isorigin && imp->methods->authority != NULL) {
+		MAYBE_LOCK(sdb);
+		result = imp->methods->authority(sdb->zone, sdb->dbdata, node);
+		MAYBE_UNLOCK(sdb);
+		if (result != ISC_R_SUCCESS) {
+			destroynode(node);
+			return (result);
+		}
+	}
+
+	*nodep = node;
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+findext(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_dbnode_t **nodep, dns_name_t *foundname,
+	dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo,
+	dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) {
+	dns_sdb_t *sdb = (dns_sdb_t *)db;
+	dns_dbnode_t *node = NULL;
+	dns_fixedname_t fname;
+	dns_rdataset_t xrdataset;
+	dns_name_t *xname;
+	unsigned int nlabels, olabels;
+	isc_result_t result;
+	unsigned int i;
+	unsigned int flags;
+
+	REQUIRE(VALID_SDB(sdb));
+	REQUIRE(nodep == NULL || *nodep == NULL);
+	REQUIRE(version == NULL || version == (void *)&dummy);
+
+	UNUSED(options);
+
+	if (!dns_name_issubdomain(name, &db->origin)) {
+		return (DNS_R_NXDOMAIN);
+	}
+
+	olabels = dns_name_countlabels(&db->origin);
+	nlabels = dns_name_countlabels(name);
+
+	xname = dns_fixedname_initname(&fname);
+
+	if (rdataset == NULL) {
+		dns_rdataset_init(&xrdataset);
+		rdataset = &xrdataset;
+	}
+
+	result = DNS_R_NXDOMAIN;
+	flags = sdb->implementation->flags;
+	i = (flags & DNS_SDBFLAG_DNS64) != 0 ? nlabels : olabels;
+	for (; i <= nlabels; i++) {
+		/*
+		 * Look up the next label.
+		 */
+		dns_name_getlabelsequence(name, nlabels - i, i, xname);
+		result = findnodeext(db, xname, false, methods, clientinfo,
+				     &node);
+		if (result == ISC_R_NOTFOUND) {
+			/*
+			 * No data at zone apex?
+			 */
+			if (i == olabels) {
+				return (DNS_R_BADDB);
+			}
+			result = DNS_R_NXDOMAIN;
+			continue;
+		}
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+
+		/*
+		 * DNS64 zone's don't have DNAME or NS records.
+		 */
+		if ((flags & DNS_SDBFLAG_DNS64) != 0) {
+			goto skip;
+		}
+
+		/*
+		 * DNS64 zone's don't have DNAME or NS records.
+		 */
+		if ((flags & DNS_SDBFLAG_DNS64) != 0) {
+			goto skip;
+		}
+
+		/*
+		 * Look for a DNAME at the current label, unless this is
+		 * the qname.
+		 */
+		if (i < nlabels) {
+			result = findrdataset(db, node, version,
+					      dns_rdatatype_dname, 0, now,
+					      rdataset, sigrdataset);
+			if (result == ISC_R_SUCCESS) {
+				result = DNS_R_DNAME;
+				break;
+			}
+		}
+
+		/*
+		 * Look for an NS at the current label, unless this is the
+		 * origin or glue is ok.
+		 */
+		if (i != olabels && (options & DNS_DBFIND_GLUEOK) == 0) {
+			result = findrdataset(db, node, version,
+					      dns_rdatatype_ns, 0, now,
+					      rdataset, sigrdataset);
+			if (result == ISC_R_SUCCESS) {
+				if (i == nlabels && type == dns_rdatatype_any) {
+					result = DNS_R_ZONECUT;
+					dns_rdataset_disassociate(rdataset);
+					if (sigrdataset != NULL &&
+					    dns_rdataset_isassociated(
+						    sigrdataset))
+					{
+						dns_rdataset_disassociate(
+							sigrdataset);
+					}
+				} else {
+					result = DNS_R_DELEGATION;
+				}
+				break;
+			}
+		}
+
+		/*
+		 * If the current name is not the qname, add another label
+		 * and try again.
+		 */
+		if (i < nlabels) {
+			destroynode(node);
+			node = NULL;
+			continue;
+		}
+
+	skip:
+		/*
+		 * If we're looking for ANY, we're done.
+		 */
+		if (type == dns_rdatatype_any) {
+			result = ISC_R_SUCCESS;
+			break;
+		}
+
+		/*
+		 * Look for the qtype.
+		 */
+		result = findrdataset(db, node, version, type, 0, now, rdataset,
+				      sigrdataset);
+		if (result == ISC_R_SUCCESS) {
+			break;
+		}
+
+		/*
+		 * Look for a CNAME
+		 */
+		if (type != dns_rdatatype_cname) {
+			result = findrdataset(db, node, version,
+					      dns_rdatatype_cname, 0, now,
+					      rdataset, sigrdataset);
+			if (result == ISC_R_SUCCESS) {
+				result = DNS_R_CNAME;
+				break;
+			}
+		}
+
+		result = DNS_R_NXRRSET;
+		break;
+	}
+
+	if (rdataset == &xrdataset && dns_rdataset_isassociated(rdataset)) {
+		dns_rdataset_disassociate(rdataset);
+	}
+
+	if (foundname != NULL) {
+		dns_name_copy(xname, foundname);
+	}
+
+	if (nodep != NULL) {
+		*nodep = node;
+	} else if (node != NULL) {
+		detachnode(db, &node);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+findzonecut(dns_db_t *db, const dns_name_t *name, unsigned int options,
+	    isc_stdtime_t now, dns_dbnode_t **nodep, dns_name_t *foundname,
+	    dns_name_t *dcname, dns_rdataset_t *rdataset,
+	    dns_rdataset_t *sigrdataset) {
+	UNUSED(db);
+	UNUSED(name);
+	UNUSED(options);
+	UNUSED(now);
+	UNUSED(nodep);
+	UNUSED(foundname);
+	UNUSED(dcname);
+	UNUSED(rdataset);
+	UNUSED(sigrdataset);
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static void
+attachnode(dns_db_t *db, dns_dbnode_t *source, dns_dbnode_t **targetp) {
+	dns_sdb_t *sdb = (dns_sdb_t *)db;
+	dns_sdbnode_t *node = (dns_sdbnode_t *)source;
+
+	REQUIRE(VALID_SDB(sdb));
+
+	UNUSED(sdb);
+
+	isc_refcount_increment(&node->references);
+
+	*targetp = source;
+}
+
+static void
+detachnode(dns_db_t *db, dns_dbnode_t **targetp) {
+	dns_sdb_t *sdb = (dns_sdb_t *)db;
+	dns_sdbnode_t *node;
+
+	REQUIRE(VALID_SDB(sdb));
+	REQUIRE(targetp != NULL && *targetp != NULL);
+
+	UNUSED(sdb);
+
+	node = (dns_sdbnode_t *)(*targetp);
+
+	*targetp = NULL;
+
+	if (isc_refcount_decrement(&node->references) == 1) {
+		destroynode(node);
+	}
+}
+
+static isc_result_t
+expirenode(dns_db_t *db, dns_dbnode_t *node, isc_stdtime_t now) {
+	UNUSED(db);
+	UNUSED(node);
+	UNUSED(now);
+	UNREACHABLE();
+}
+
+static void
+printnode(dns_db_t *db, dns_dbnode_t *node, FILE *out) {
+	UNUSED(db);
+	UNUSED(node);
+	UNUSED(out);
+	return;
+}
+
+static isc_result_t
+createiterator(dns_db_t *db, unsigned int options,
+	       dns_dbiterator_t **iteratorp) {
+	dns_sdb_t *sdb = (dns_sdb_t *)db;
+	REQUIRE(VALID_SDB(sdb));
+
+	sdb_dbiterator_t *sdbiter;
+	isc_result_t result;
+	dns_sdbimplementation_t *imp = sdb->implementation;
+
+	if (imp->methods->allnodes == NULL) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	if ((options & DNS_DB_NSEC3ONLY) != 0 ||
+	    (options & DNS_DB_NONSEC3) != 0)
+	{
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	sdbiter = isc_mem_get(sdb->common.mctx, sizeof(sdb_dbiterator_t));
+
+	sdbiter->common.methods = &dbiterator_methods;
+	sdbiter->common.db = NULL;
+	dns_db_attach(db, &sdbiter->common.db);
+	sdbiter->common.relative_names = ((options & DNS_DB_RELATIVENAMES) !=
+					  0);
+	sdbiter->common.magic = DNS_DBITERATOR_MAGIC;
+	ISC_LIST_INIT(sdbiter->nodelist);
+	sdbiter->current = NULL;
+	sdbiter->origin = NULL;
+
+	MAYBE_LOCK(sdb);
+	result = imp->methods->allnodes(sdb->zone, sdb->dbdata, sdbiter);
+	MAYBE_UNLOCK(sdb);
+	if (result != ISC_R_SUCCESS) {
+		dbiterator_destroy((dns_dbiterator_t **)(void *)&sdbiter);
+		return (result);
+	}
+
+	if (sdbiter->origin != NULL) {
+		ISC_LIST_UNLINK(sdbiter->nodelist, sdbiter->origin, link);
+		ISC_LIST_PREPEND(sdbiter->nodelist, sdbiter->origin, link);
+	}
+
+	*iteratorp = (dns_dbiterator_t *)sdbiter;
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+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) {
+	REQUIRE(VALID_SDBNODE(node));
+
+	dns_rdatalist_t *list;
+	dns_sdbnode_t *sdbnode = (dns_sdbnode_t *)node;
+
+	UNUSED(db);
+	UNUSED(version);
+	UNUSED(covers);
+	UNUSED(now);
+	UNUSED(sigrdataset);
+
+	if (type == dns_rdatatype_rrsig) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	list = ISC_LIST_HEAD(sdbnode->lists);
+	while (list != NULL) {
+		if (list->type == type) {
+			break;
+		}
+		list = ISC_LIST_NEXT(list, link);
+	}
+	if (list == NULL) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	list_tordataset(list, db, node, rdataset);
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
+	     unsigned int options, isc_stdtime_t now,
+	     dns_rdatasetiter_t **iteratorp) {
+	sdb_rdatasetiter_t *iterator;
+
+	REQUIRE(version == NULL || version == &dummy);
+
+	UNUSED(version);
+	UNUSED(now);
+
+	iterator = isc_mem_get(db->mctx, sizeof(sdb_rdatasetiter_t));
+
+	iterator->common.magic = DNS_RDATASETITER_MAGIC;
+	iterator->common.methods = &rdatasetiter_methods;
+	iterator->common.db = db;
+	iterator->common.node = NULL;
+	attachnode(db, node, &iterator->common.node);
+	iterator->common.version = version;
+	iterator->common.options = options;
+	iterator->common.now = now;
+
+	*iteratorp = (dns_rdatasetiter_t *)iterator;
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+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) {
+	UNUSED(db);
+	UNUSED(node);
+	UNUSED(version);
+	UNUSED(now);
+	UNUSED(rdataset);
+	UNUSED(options);
+	UNUSED(addedrdataset);
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static isc_result_t
+subtractrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
+		 dns_rdataset_t *rdataset, unsigned int options,
+		 dns_rdataset_t *newrdataset) {
+	UNUSED(db);
+	UNUSED(node);
+	UNUSED(version);
+	UNUSED(rdataset);
+	UNUSED(options);
+	UNUSED(newrdataset);
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static isc_result_t
+deleterdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
+	       dns_rdatatype_t type, dns_rdatatype_t covers) {
+	UNUSED(db);
+	UNUSED(node);
+	UNUSED(version);
+	UNUSED(type);
+	UNUSED(covers);
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+static bool
+issecure(dns_db_t *db) {
+	UNUSED(db);
+
+	return (false);
+}
+
+static unsigned int
+nodecount(dns_db_t *db, dns_dbtree_t tree) {
+	UNUSED(db);
+	UNUSED(tree);
+
+	return (0);
+}
+
+static bool
+ispersistent(dns_db_t *db) {
+	UNUSED(db);
+	return (true);
+}
+
+static void
+overmem(dns_db_t *db, bool over) {
+	UNUSED(db);
+	UNUSED(over);
+}
+
+static void
+settask(dns_db_t *db, isc_task_t *task) {
+	UNUSED(db);
+	UNUSED(task);
+}
+
+static dns_dbmethods_t sdb_methods = {
+	attach,		detach,
+	beginload,	endload,
+	dump,		currentversion,
+	newversion,	attachversion,
+	closeversion,	NULL, /* findnode */
+	NULL,		      /* find */
+	findzonecut,	attachnode,
+	detachnode,	expirenode,
+	printnode,	createiterator,
+	findrdataset,	allrdatasets,
+	addrdataset,	subtractrdataset,
+	deleterdataset, issecure,
+	nodecount,	ispersistent,
+	overmem,	settask,
+	getoriginnode, /* getoriginnode */
+	NULL,	       /* transfernode */
+	NULL,	       /* getnsec3parameters */
+	NULL,	       /* findnsec3node */
+	NULL,	       /* setsigningtime */
+	NULL,	       /* getsigningtime */
+	NULL,	       /* resigned */
+	NULL,	       /* isdnssec */
+	NULL,	       /* getrrsetstats */
+	NULL,	       /* rpz_attach */
+	NULL,	       /* rpz_ready */
+	findnodeext,	findext,
+	NULL, /* setcachestats */
+	NULL, /* hashsize */
+	NULL, /* nodefullname */
+	NULL, /* getsize */
+	NULL, /* setservestalettl */
+	NULL, /* getservestalettl */
+	NULL, /* setservestalerefresh */
+	NULL, /* getservestalerefresh */
+	NULL, /* setgluecachestats */
+};
+
+static isc_result_t
+dns_sdb_create(isc_mem_t *mctx, const dns_name_t *origin, dns_dbtype_t type,
+	       dns_rdataclass_t rdclass, unsigned int argc, char *argv[],
+	       void *driverarg, dns_db_t **dbp) {
+	dns_sdb_t *sdb;
+	isc_result_t result;
+	char zonestr[DNS_NAME_MAXTEXT + 1];
+	isc_buffer_t b;
+	dns_sdbimplementation_t *imp;
+
+	REQUIRE(driverarg != NULL);
+
+	imp = driverarg;
+
+	if (type != dns_dbtype_zone) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	sdb = isc_mem_get(mctx, sizeof(dns_sdb_t));
+	memset(sdb, 0, sizeof(dns_sdb_t));
+
+	dns_name_init(&sdb->common.origin, NULL);
+	sdb->common.attributes = 0;
+	sdb->common.methods = &sdb_methods;
+	sdb->common.rdclass = rdclass;
+	sdb->common.mctx = NULL;
+	sdb->implementation = imp;
+
+	isc_mem_attach(mctx, &sdb->common.mctx);
+
+	result = dns_name_dupwithoffsets(origin, mctx, &sdb->common.origin);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_lock;
+	}
+
+	isc_buffer_init(&b, zonestr, sizeof(zonestr));
+	result = dns_name_totext(origin, true, &b);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_origin;
+	}
+	isc_buffer_putuint8(&b, 0);
+
+	sdb->zone = isc_mem_strdup(mctx, zonestr);
+
+	sdb->dbdata = NULL;
+	if (imp->methods->create != NULL) {
+		MAYBE_LOCK(sdb);
+		result = imp->methods->create(sdb->zone, argc, argv,
+					      imp->driverdata, &sdb->dbdata);
+		MAYBE_UNLOCK(sdb);
+		if (result != ISC_R_SUCCESS) {
+			goto cleanup_zonestr;
+		}
+	}
+
+	isc_refcount_init(&sdb->references, 1);
+
+	sdb->common.magic = DNS_DB_MAGIC;
+	sdb->common.impmagic = SDB_MAGIC;
+
+	*dbp = (dns_db_t *)sdb;
+
+	return (ISC_R_SUCCESS);
+
+cleanup_zonestr:
+	isc_mem_free(mctx, sdb->zone);
+cleanup_origin:
+	dns_name_free(&sdb->common.origin, mctx);
+cleanup_lock:
+	isc_mem_putanddetach(&mctx, sdb, sizeof(dns_sdb_t));
+
+	return (result);
+}
+
+/*
+ * Rdataset Methods
+ */
+
+static void
+disassociate(dns_rdataset_t *rdataset) {
+	dns_dbnode_t *node = rdataset->private5;
+	dns_sdbnode_t *sdbnode = (dns_sdbnode_t *)node;
+	dns_db_t *db = (dns_db_t *)sdbnode->sdb;
+
+	detachnode(db, &node);
+	isc__rdatalist_disassociate(rdataset);
+}
+
+static void
+rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
+	dns_dbnode_t *node = source->private5;
+	dns_sdbnode_t *sdbnode = (dns_sdbnode_t *)node;
+	dns_db_t *db = (dns_db_t *)sdbnode->sdb;
+	dns_dbnode_t *tempdb = NULL;
+
+	isc__rdatalist_clone(source, target);
+	attachnode(db, node, &tempdb);
+	source->private5 = tempdb;
+}
+
+static dns_rdatasetmethods_t sdb_rdataset_methods = {
+	disassociate,
+	isc__rdatalist_first,
+	isc__rdatalist_next,
+	isc__rdatalist_current,
+	rdataset_clone,
+	isc__rdatalist_count,
+	isc__rdatalist_addnoqname,
+	isc__rdatalist_getnoqname,
+	NULL, /* addclosest */
+	NULL, /* getclosest */
+	NULL, /* settrust */
+	NULL, /* expire */
+	NULL, /* clearprefetch */
+	NULL, /* setownercase */
+	NULL, /* getownercase */
+	NULL  /* addglue */
+};
+
+static void
+list_tordataset(dns_rdatalist_t *rdatalist, dns_db_t *db, dns_dbnode_t *node,
+		dns_rdataset_t *rdataset) {
+	/*
+	 * The sdb rdataset is an rdatalist with some additions.
+	 *	- private1 & private2 are used by the rdatalist.
+	 *	- private3 & private 4 are unused.
+	 *	- private5 is the node.
+	 */
+
+	/* This should never fail. */
+	RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset) ==
+		      ISC_R_SUCCESS);
+
+	rdataset->methods = &sdb_rdataset_methods;
+	dns_db_attachnode(db, node, &rdataset->private5);
+}
+
+/*
+ * Database Iterator Methods
+ */
+static void
+dbiterator_destroy(dns_dbiterator_t **iteratorp) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)(*iteratorp);
+	dns_sdb_t *sdb = (dns_sdb_t *)sdbiter->common.db;
+
+	while (!ISC_LIST_EMPTY(sdbiter->nodelist)) {
+		dns_sdbnode_t *node;
+		node = ISC_LIST_HEAD(sdbiter->nodelist);
+		ISC_LIST_UNLINK(sdbiter->nodelist, node, link);
+		destroynode(node);
+	}
+
+	dns_db_detach(&sdbiter->common.db);
+	isc_mem_put(sdb->common.mctx, sdbiter, sizeof(sdb_dbiterator_t));
+
+	*iteratorp = NULL;
+}
+
+static isc_result_t
+dbiterator_first(dns_dbiterator_t *iterator) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)iterator;
+
+	sdbiter->current = ISC_LIST_HEAD(sdbiter->nodelist);
+	if (sdbiter->current == NULL) {
+		return (ISC_R_NOMORE);
+	} else {
+		return (ISC_R_SUCCESS);
+	}
+}
+
+static isc_result_t
+dbiterator_last(dns_dbiterator_t *iterator) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)iterator;
+
+	sdbiter->current = ISC_LIST_TAIL(sdbiter->nodelist);
+	if (sdbiter->current == NULL) {
+		return (ISC_R_NOMORE);
+	} else {
+		return (ISC_R_SUCCESS);
+	}
+}
+
+static isc_result_t
+dbiterator_seek(dns_dbiterator_t *iterator, const dns_name_t *name) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)iterator;
+
+	sdbiter->current = ISC_LIST_HEAD(sdbiter->nodelist);
+	while (sdbiter->current != NULL) {
+		if (dns_name_equal(sdbiter->current->name, name)) {
+			return (ISC_R_SUCCESS);
+		}
+		sdbiter->current = ISC_LIST_NEXT(sdbiter->current, link);
+	}
+	return (ISC_R_NOTFOUND);
+}
+
+static isc_result_t
+dbiterator_prev(dns_dbiterator_t *iterator) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)iterator;
+
+	sdbiter->current = ISC_LIST_PREV(sdbiter->current, link);
+	if (sdbiter->current == NULL) {
+		return (ISC_R_NOMORE);
+	} else {
+		return (ISC_R_SUCCESS);
+	}
+}
+
+static isc_result_t
+dbiterator_next(dns_dbiterator_t *iterator) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)iterator;
+
+	sdbiter->current = ISC_LIST_NEXT(sdbiter->current, link);
+	if (sdbiter->current == NULL) {
+		return (ISC_R_NOMORE);
+	} else {
+		return (ISC_R_SUCCESS);
+	}
+}
+
+static isc_result_t
+dbiterator_current(dns_dbiterator_t *iterator, dns_dbnode_t **nodep,
+		   dns_name_t *name) {
+	sdb_dbiterator_t *sdbiter = (sdb_dbiterator_t *)iterator;
+
+	attachnode(iterator->db, sdbiter->current, nodep);
+	if (name != NULL) {
+		dns_name_copy(sdbiter->current->name, name);
+		return (ISC_R_SUCCESS);
+	}
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+dbiterator_pause(dns_dbiterator_t *iterator) {
+	UNUSED(iterator);
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+dbiterator_origin(dns_dbiterator_t *iterator, dns_name_t *name) {
+	UNUSED(iterator);
+	dns_name_copy(dns_rootname, name);
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Rdataset Iterator Methods
+ */
+
+static void
+rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp) {
+	sdb_rdatasetiter_t *sdbiterator = (sdb_rdatasetiter_t *)(*iteratorp);
+	detachnode(sdbiterator->common.db, &sdbiterator->common.node);
+	isc_mem_put(sdbiterator->common.db->mctx, sdbiterator,
+		    sizeof(sdb_rdatasetiter_t));
+	*iteratorp = NULL;
+}
+
+static isc_result_t
+rdatasetiter_first(dns_rdatasetiter_t *iterator) {
+	sdb_rdatasetiter_t *sdbiterator = (sdb_rdatasetiter_t *)iterator;
+	dns_sdbnode_t *sdbnode = (dns_sdbnode_t *)iterator->node;
+
+	if (ISC_LIST_EMPTY(sdbnode->lists)) {
+		return (ISC_R_NOMORE);
+	}
+	sdbiterator->current = ISC_LIST_HEAD(sdbnode->lists);
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+rdatasetiter_next(dns_rdatasetiter_t *iterator) {
+	sdb_rdatasetiter_t *sdbiterator = (sdb_rdatasetiter_t *)iterator;
+
+	sdbiterator->current = ISC_LIST_NEXT(sdbiterator->current, link);
+	if (sdbiterator->current == NULL) {
+		return (ISC_R_NOMORE);
+	} else {
+		return (ISC_R_SUCCESS);
+	}
+}
+
+static void
+rdatasetiter_current(dns_rdatasetiter_t *iterator, dns_rdataset_t *rdataset) {
+	sdb_rdatasetiter_t *sdbiterator = (sdb_rdatasetiter_t *)iterator;
+
+	list_tordataset(sdbiterator->current, iterator->db, iterator->node,
+			rdataset);
+}