Adding upstream version 1:9.16.44.upstream/1%9.16.44upstream

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

24 files changed, 8815 insertions, 0 deletions

diff --git a/contrib/dlz/drivers/dlz_bdb_driver.c b/contrib/dlz/drivers/dlz_bdb_driver.c
new file mode 100644
index 0000000..5cce7ce
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_bdb_driver.c
@@ -0,0 +1,780 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_BDB
+#include <db.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_bdb_driver.h>
+#include <named/globals.h>
+
+static dns_sdlzimplementation_t *dlz_bdb = NULL;
+
+/* should the bdb driver use threads. */
+#define bdb_threads DB_THREAD
+
+/* BDB database names */
+#define dlz_data   "dns_data"
+#define dlz_zone   "dns_zone"
+#define dlz_host   "dns_host"
+#define dlz_client "dns_client"
+
+/*%
+ * This structure contains all the Berkeley DB handles
+ * for this instance of the BDB driver.
+ */
+
+typedef struct bdb_instance {
+	DB_ENV *dbenv;	 /*%< BDB environment */
+	DB *data;	 /*%< dns_data database handle */
+	DB *zone;	 /*%< zone database handle */
+	DB *host;	 /*%< host database handle */
+	DB *client;	 /*%< client database handle */
+	isc_mem_t *mctx; /*%< memory context */
+} bdb_instance_t;
+
+typedef struct parsed_data {
+	char *zone;
+	char *host;
+	char *type;
+	int ttl;
+	char *data;
+} parsed_data_t;
+
+/* forward reference */
+
+static isc_result_t
+bdb_findzone(void *driverarg, void *dbdata, const char *name,
+	     dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo);
+
+/*%
+ * Parses the DBT from the Berkeley DB into a parsed_data record
+ * The parsed_data record should be allocated before and passed into the
+ * bdb_parse_data function.  The char (type & data) fields should not
+ * be "free"d as that memory is part of the DBT data field.  It will be
+ * "free"d when the DBT is freed.
+ */
+
+static isc_result_t
+bdb_parse_data(char *in, parsed_data_t *pd) {
+	char *endp, *ttlStr;
+	char *tmp = in;
+	char *lastchar = (char *)&tmp[strlen(tmp) + 1];
+
+	/*%
+	 * String should be formatted as:
+	 * zone(a space)host(a space)ttl(a space)type(a space)remaining data
+	 * examples:
+	 * example.com www 10 A 127.0.0.1
+	 * example.com mail 10 A 127.0.0.2
+	 * example.com @ 10 MX 20 mail.example.com
+	 */
+
+	/* save pointer to zone */
+	pd->zone = tmp;
+
+	/* find space after zone and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to host */
+	pd->host = tmp;
+
+	/* find space after type and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to dns type */
+	pd->type = tmp;
+
+	/* find space after type and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to dns ttl */
+	ttlStr = tmp;
+
+	/* find space after ttl and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to remainder of DNS data */
+	pd->data = tmp;
+
+	/* convert ttl string to integer */
+	pd->ttl = strtol(ttlStr, &endp, 10);
+	if (*endp != '\0' || pd->ttl < 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB driver ttl must be a positive number");
+		return (ISC_R_FAILURE);
+	}
+
+	/* if we get this far everything should have worked. */
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * DLZ methods
+ */
+
+static isc_result_t
+bdb_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		 const char *client) {
+	isc_result_t result;
+	bdb_instance_t *db = (bdb_instance_t *)dbdata;
+	DBC *client_cursor = NULL;
+	DBT key, data;
+
+	/* check to see if we are authoritative for the zone first. */
+	result = bdb_findzone(driverarg, dbdata, name, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	memset(&key, 0, sizeof(DBT));
+	key.flags = DB_DBT_MALLOC;
+	key.data = strdup(name);
+	if (key.data == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto xfr_cleanup;
+	}
+	key.size = strlen(key.data);
+
+	memset(&data, 0, sizeof(DBT));
+	data.flags = DB_DBT_MALLOC;
+	data.data = strdup(client);
+	if (data.data == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto xfr_cleanup;
+	}
+	data.size = strlen(data.data);
+
+	/* get a cursor to loop through zone data */
+	if (db->client->cursor(db->client, NULL, &client_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto xfr_cleanup;
+	}
+
+	switch (client_cursor->c_get(client_cursor, &key, &data, DB_GET_BOTH)) {
+	case DB_NOTFOUND:
+	case DB_SECONDARY_BAD:
+		result = ISC_R_NOTFOUND;
+		break;
+	case 0:
+		result = ISC_R_SUCCESS;
+		break;
+	default:
+		result = ISC_R_FAILURE;
+	}
+
+xfr_cleanup:
+
+	/* free any memory duplicate string in the key field */
+	if (key.data != NULL) {
+		free(key.data);
+	}
+
+	/* free any memory allocated to the data field. */
+	if (data.data != NULL) {
+		free(data.data);
+	}
+
+	/* get rid of zone_cursor */
+	if (client_cursor != NULL) {
+		client_cursor->c_close(client_cursor);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+bdb_allnodes(const char *zone, void *driverarg, void *dbdata,
+	     dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result = ISC_R_NOTFOUND;
+	bdb_instance_t *db = (bdb_instance_t *)dbdata;
+	DBC *zone_cursor = NULL;
+	DBT key, data;
+	int flags;
+	int bdbres;
+	parsed_data_t pd;
+	char *tmp = NULL, *tmp_zone;
+
+	UNUSED(driverarg);
+
+	memset(&key, 0, sizeof(DBT));
+	memset(&data, 0, sizeof(DBT));
+
+	key.data = tmp_zone = strdup(zone);
+
+	if (key.data == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	key.size = strlen(key.data);
+
+	/* get a cursor to loop through zone data */
+	if (db->zone->cursor(db->zone, NULL, &zone_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto allnodes_cleanup;
+	}
+
+	flags = DB_SET;
+
+	while ((bdbres = zone_cursor->c_get(zone_cursor, &key, &data, flags)) ==
+	       0)
+	{
+		flags = DB_NEXT_DUP;
+
+		tmp = realloc(tmp, data.size + 1);
+		if (tmp == NULL) {
+			goto allnodes_cleanup;
+		}
+
+		strncpy(tmp, data.data, data.size);
+		tmp[data.size] = '\0';
+
+		if (bdb_parse_data(tmp, &pd) != ISC_R_SUCCESS) {
+			goto allnodes_cleanup;
+		}
+
+		result = dns_sdlz_putnamedrr(allnodes, pd.host, pd.type, pd.ttl,
+					     pd.data);
+		if (result != ISC_R_SUCCESS) {
+			goto allnodes_cleanup;
+		}
+	} /* end while loop */
+
+allnodes_cleanup:
+
+	if (tmp != NULL) {
+		free(tmp);
+	}
+
+	/* free any memory duplicate string in the key field */
+	if (tmp_zone != NULL) {
+		free(tmp_zone);
+	}
+
+	/* get rid of zone_cursor */
+	if (zone_cursor != NULL) {
+		zone_cursor->c_close(zone_cursor);
+	}
+
+	return (result);
+}
+
+/*%
+ * Performs BDB cleanup.
+ * Used by bdb_create if there is an error starting up.
+ * Used by bdb_destroy when the driver is shutting down.
+ */
+
+static void
+bdb_cleanup(bdb_instance_t *db) {
+	isc_mem_t *mctx;
+
+	/* close databases */
+	if (db->data != NULL) {
+		db->data->close(db->data, 0);
+	}
+	if (db->host != NULL) {
+		db->host->close(db->host, 0);
+	}
+	if (db->zone != NULL) {
+		db->zone->close(db->zone, 0);
+	}
+	if (db->client != NULL) {
+		db->client->close(db->client, 0);
+	}
+
+	/* close environment */
+	if (db->dbenv != NULL) {
+		db->dbenv->close(db->dbenv, 0);
+	}
+
+	/* cleanup memory */
+	if (db->mctx != NULL) {
+		/* save mctx for later */
+		mctx = db->mctx;
+		/* return, and detach the memory */
+		isc_mem_putanddetach(&mctx, db, sizeof(bdb_instance_t));
+	}
+}
+
+static isc_result_t
+bdb_findzone(void *driverarg, void *dbdata, const char *name,
+	     dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	bdb_instance_t *db = (bdb_instance_t *)dbdata;
+	DBC *zone_cursor = NULL;
+	DBT key, data;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	memset(&key, 0, sizeof(DBT));
+	memset(&data, 0, sizeof(DBT));
+	data.flags = DB_DBT_MALLOC;
+
+	key.data = strdup(name);
+
+	if (key.data == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	key.size = strlen(key.data);
+
+	/* get a cursor to loop through zone data */
+	if (db->zone->cursor(db->zone, NULL, &zone_cursor, 0) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto findzone_cleanup;
+	}
+
+	switch (zone_cursor->c_get(zone_cursor, &key, &data, DB_SET)) {
+	case DB_NOTFOUND:
+	case DB_SECONDARY_BAD:
+		result = ISC_R_NOTFOUND;
+		break;
+	case 0:
+		result = ISC_R_SUCCESS;
+		break;
+	default:
+		result = ISC_R_FAILURE;
+	}
+
+findzone_cleanup:
+
+	/* free any memory duplicate string in the key field */
+	if (key.data != NULL) {
+		free(key.data);
+	}
+
+	/* free any memory allocated to the data field. */
+	if (data.data != NULL) {
+		free(data.data);
+	}
+
+	/* get rid of zone_cursor */
+	if (zone_cursor != NULL) {
+		zone_cursor->c_close(zone_cursor);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+bdb_lookup(const char *zone, const char *name, void *driverarg, void *dbdata,
+	   dns_sdlzlookup_t *lookup, dns_clientinfomethods_t *methods,
+	   dns_clientinfo_t *clientinfo) {
+	isc_result_t result = ISC_R_NOTFOUND;
+	bdb_instance_t *db = (bdb_instance_t *)dbdata;
+	DBC *zone_cursor = NULL;
+	DBC *host_cursor = NULL;
+	DBC *join_cursor = NULL;
+	DBT key, data;
+	DBC *cur_arr[3];
+	int bdbres;
+	parsed_data_t pd;
+	char *tmp_zone, *tmp_host = NULL;
+	char *tmp = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	memset(&key, 0, sizeof(DBT));
+	memset(&data, 0, sizeof(DBT));
+
+	/* set zone key */
+	key.data = tmp_zone = strdup(zone);
+	if (key.data == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto lookup_cleanup;
+	}
+	key.size = strlen(key.data);
+
+	/* get a cursor to loop through zone data */
+	if (db->zone->cursor(db->zone, NULL, &zone_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto lookup_cleanup;
+	}
+
+	/* initialize zone_cursor with zone_key */
+	if (zone_cursor->c_get(zone_cursor, &key, &data, DB_SET) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto lookup_cleanup;
+	}
+
+	/* set host key */
+	key.data = tmp_host = strdup(name);
+	if (key.data == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto lookup_cleanup;
+	}
+	key.size = strlen(key.data);
+
+	/* get a cursor to loop through host data */
+	if (db->host->cursor(db->host, NULL, &host_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto lookup_cleanup;
+	}
+
+	/* initialize host_cursor with host_key */
+	if (host_cursor->c_get(host_cursor, &key, &data, DB_SET) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto lookup_cleanup;
+	}
+
+	cur_arr[0] = zone_cursor;
+	cur_arr[1] = host_cursor;
+	cur_arr[2] = NULL;
+
+	db->data->join(db->data, cur_arr, &join_cursor, 0);
+
+	while ((bdbres = join_cursor->c_get(join_cursor, &key, &data, 0)) == 0)
+	{
+		tmp = realloc(tmp, data.size + 1);
+		if (tmp == NULL) {
+			goto lookup_cleanup;
+		}
+
+		strncpy(tmp, data.data, data.size);
+		tmp[data.size] = '\0';
+
+		if (bdb_parse_data(tmp, &pd) != ISC_R_SUCCESS) {
+			goto lookup_cleanup;
+		}
+
+		result = dns_sdlz_putrr(lookup, pd.type, pd.ttl, pd.data);
+
+		if (result != ISC_R_SUCCESS) {
+			goto lookup_cleanup;
+		}
+	} /* end while loop */
+
+lookup_cleanup:
+
+	if (tmp != NULL) {
+		free(tmp);
+	}
+	if (tmp_zone != NULL) {
+		free(tmp_zone);
+	}
+	if (tmp_host != NULL) {
+		free(tmp_host);
+	}
+
+	/* get rid of the joined cusor */
+	if (join_cursor != NULL) {
+		join_cursor->c_close(join_cursor);
+	}
+
+	/* get rid of zone_cursor */
+	if (zone_cursor != NULL) {
+		zone_cursor->c_close(zone_cursor);
+	}
+
+	/* get rid of host_cursor */
+	if (host_cursor != NULL) {
+		host_cursor->c_close(host_cursor);
+	}
+
+	return (result);
+}
+
+/*% Initializes, sets flags and then opens Berkeley databases. */
+
+static isc_result_t
+bdb_opendb(DB_ENV *db_env, DBTYPE db_type, DB **db, const char *db_name,
+	   char *db_file, int flags) {
+	int result;
+
+	/* Initialize the database. */
+	if ((result = db_create(db, db_env, 0)) != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB could not initialize %s database. "
+			      "BDB error: %s",
+			      db_name, db_strerror(result));
+		return (ISC_R_FAILURE);
+	}
+
+	/* set database flags. */
+	if ((result = (*db)->set_flags(*db, flags)) != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB could not set flags for %s database. "
+			      "BDB error: %s",
+			      db_name, db_strerror(result));
+		return (ISC_R_FAILURE);
+	}
+
+	/* open the database. */
+	if ((result = (*db)->open(*db, NULL, db_file, db_name, db_type,
+				  DB_RDONLY | bdb_threads, 0)) != 0)
+	{
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB could not open %s database in %s. "
+			      "BDB error: %s",
+			      db_name, db_file, db_strerror(result));
+		return (ISC_R_FAILURE);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+bdb_create(const char *dlzname, unsigned int argc, char *argv[],
+	   void *driverarg, void **dbdata) {
+	isc_result_t result;
+	int bdbres;
+	bdb_instance_t *db = NULL;
+
+	UNUSED(dlzname);
+	UNUSED(driverarg);
+
+	/* verify we have 3 arg's passed to the driver */
+	if (argc != 3) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Berkeley DB driver requires at least "
+			      "2 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* allocate and zero memory for driver structure */
+	db = isc_mem_get(named_g_mctx, sizeof(bdb_instance_t));
+	memset(db, 0, sizeof(bdb_instance_t));
+
+	/* attach to the memory context */
+	isc_mem_attach(named_g_mctx, &db->mctx);
+
+	/* create BDB environment
+	 * Basically BDB allocates and assigns memory to db->dbenv
+	 */
+	bdbres = db_env_create(&db->dbenv, 0);
+	if (bdbres != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB environment could not be created. "
+			      "BDB error: %s",
+			      db_strerror(bdbres));
+		result = ISC_R_FAILURE;
+		goto init_cleanup;
+	}
+
+	/* open BDB environment */
+	bdbres = db->dbenv->open(
+		db->dbenv, argv[1],
+		DB_INIT_CDB | DB_INIT_MPOOL | bdb_threads | DB_CREATE, 0);
+	if (bdbres != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB environment at '%s' could not be opened. "
+			      "BDB error: %s",
+			      argv[1], db_strerror(bdbres));
+		result = ISC_R_FAILURE;
+		goto init_cleanup;
+	}
+
+	/* open dlz_data database. */
+	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->data, dlz_data, argv[2],
+			    0);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* open dlz_host database. */
+	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->host, dlz_host, argv[2],
+			    DB_DUP | DB_DUPSORT);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* open dlz_zone database. */
+	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->zone, dlz_zone, argv[2],
+			    DB_DUP | DB_DUPSORT);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* open dlz_client database. */
+	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->client, dlz_client,
+			    argv[2], DB_DUP | DB_DUPSORT);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* associate the host secondary database with the primary database */
+	bdbres = db->data->associate(db->data, NULL, db->host, NULL, 0);
+	if (bdbres != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB could not associate %s database with %s. "
+			      "BDB error: %s",
+			      dlz_host, dlz_data, db_strerror(bdbres));
+		result = ISC_R_FAILURE;
+		goto init_cleanup;
+	}
+
+	/* associate the zone secondary database with the primary database */
+	bdbres = db->data->associate(db->data, NULL, db->zone, NULL, 0);
+	if (bdbres != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "BDB could not associate %s database with %s. "
+			      "BDB error: %s",
+			      dlz_zone, dlz_data, db_strerror(bdbres));
+		result = ISC_R_FAILURE;
+		goto init_cleanup;
+	}
+
+	*dbdata = db;
+
+	return (ISC_R_SUCCESS);
+
+init_cleanup:
+
+	bdb_cleanup(db);
+	return (result);
+}
+
+static void
+bdb_destroy(void *driverarg, void *dbdata) {
+	UNUSED(driverarg);
+
+	bdb_cleanup((bdb_instance_t *)dbdata);
+}
+
+/* bdb_authority not needed as authority data is returned by lookup */
+static dns_sdlzmethods_t dlz_bdb_methods = {
+	bdb_create,
+	bdb_destroy,
+	bdb_findzone,
+	bdb_lookup,
+	NULL,
+	bdb_allnodes,
+	bdb_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_bdb_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ bdb driver.");
+
+	result = dns_sdlzregister("bdb", &dlz_bdb_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA |
+					  DNS_SDLZFLAG_THREADSAFE,
+				  named_g_mctx, &dlz_bdb);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_bdb_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ bdb driver.");
+
+	if (dlz_bdb != NULL) {
+		dns_sdlzunregister(&dlz_bdb);
+	}
+}
+
+#endif /* ifdef DLZ_BDB */
diff --git a/contrib/dlz/drivers/dlz_bdbhpt_driver.c b/contrib/dlz/drivers/dlz_bdbhpt_driver.c
new file mode 100644
index 0000000..fefe99d
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_bdbhpt_driver.c
@@ -0,0 +1,849 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_BDB
+#include <db.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_bdbhpt_driver.h>
+#include <named/globals.h>
+
+static dns_sdlzimplementation_t *dlz_bdbhpt = NULL;
+
+/* should the bdb driver use threads. */
+#define bdbhpt_threads DB_THREAD
+
+/* bdbhpt database names */
+#define dlz_data   "dns_data"
+#define dlz_zone   "dns_zone"
+#define dlz_xfr	   "dns_xfr"
+#define dlz_client "dns_client"
+
+/* This structure contains all the Berkeley DB handles
+ * for this instance of the bdbhpt driver.
+ */
+
+typedef struct bdbhpt_instance {
+	DB_ENV *dbenv;	 /*%< bdbhpt environment */
+	DB *data;	 /*%< dns_data database handle */
+	DB *zone;	 /*%< zone database handle */
+	DB *xfr;	 /*%< zone xfr database handle */
+	DB *client;	 /*%< client database handle */
+	isc_mem_t *mctx; /*%< memory context */
+} bdbhpt_instance_t;
+
+typedef struct bdbhpt_parsed_data {
+	char *host;
+	char *type;
+	int ttl;
+	char *data;
+} bdbhpt_parsed_data_t;
+
+/* forward reference */
+
+static isc_result_t
+bdbhpt_findzone(void *driverarg, void *dbdata, const char *name,
+		dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo);
+
+/*%
+ * Reverses a string in place.
+ */
+
+static char *
+bdbhpt_strrev(char *str) {
+	char *p1, *p2;
+
+	if (!str || !*str) {
+		return (str);
+	}
+	for (p1 = str, p2 = str + strlen(str) - 1; p2 > p1; ++p1, --p2) {
+		*p1 ^= *p2;
+		*p2 ^= *p1;
+		*p1 ^= *p2;
+	}
+	return (str);
+}
+
+/*%
+ * Parses the DBT from the Berkeley DB into a parsed_data record
+ * The parsed_data record should be allocated before and passed into the
+ * bdbhpt_parse_data function.  The char (type & data) fields should not
+ * be "free"d as that memory is part of the DBT data field.  It will be
+ * "free"d when the DBT is freed.
+ */
+
+static isc_result_t
+bdbhpt_parse_data(char *in, bdbhpt_parsed_data_t *pd) {
+	char *endp, *ttlStr;
+	char *tmp = in;
+	char *lastchar = (char *)&tmp[strlen(tmp)];
+
+	/*%
+	 * String should be formatted as:
+	 *   replication_id
+	 *   (a space)
+	 *   host_name
+	 *   (a space)
+	 *   ttl
+	 *   (a space)
+	 *   type
+	 *   (a space)
+	 *   remaining data
+	 *
+	 * examples:
+	 *
+	 * 9191 host 10 A 127.0.0.1
+	 * server1_212 host 10 A 127.0.0.2
+	 * {xxxx-xxxx-xxxx-xxxx-xxxx} host 10 MX 20 mail.example.com
+	 */
+
+	/*
+	 * we don't need the replication id, so don't
+	 * bother saving a pointer to it.
+	 */
+
+	/* find space after replication id */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to host */
+	pd->host = tmp;
+
+	/* find space after host and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to ttl string */
+	ttlStr = tmp;
+
+	/* find space after ttl and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to dns type */
+	pd->type = tmp;
+
+	/* find space after type and change it to a '\0' */
+	tmp = strchr(tmp, ' ');
+	/* verify we found a space */
+	if (tmp == NULL) {
+		return (ISC_R_FAILURE);
+	}
+	/* change the space to a null (string terminator) */
+	tmp[0] = '\0';
+	/* make sure it is safe to increment pointer */
+	if (++tmp > lastchar) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* save pointer to remainder of DNS data */
+	pd->data = tmp;
+
+	/* convert ttl string to integer */
+	pd->ttl = strtol(ttlStr, &endp, 10);
+	if (*endp != '\0' || pd->ttl < 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt driver ttl must be a positive number");
+		return (ISC_R_FAILURE);
+	}
+
+	/* if we get this far everything should have worked. */
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * DLZ methods
+ */
+
+static isc_result_t
+bdbhpt_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		    const char *client) {
+	isc_result_t result;
+	bdbhpt_instance_t *db = (bdbhpt_instance_t *)dbdata;
+	DBT key, data;
+
+	/* check to see if we are authoritative for the zone first. */
+	result = bdbhpt_findzone(driverarg, dbdata, name, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	memset(&key, 0, sizeof(DBT));
+	key.flags = DB_DBT_MALLOC;
+	key.data = strdup(name);
+	if (key.data == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto xfr_cleanup;
+	}
+	key.size = strlen(key.data);
+
+	memset(&data, 0, sizeof(DBT));
+	data.flags = DB_DBT_MALLOC;
+	data.data = strdup(client);
+	if (data.data == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto xfr_cleanup;
+	}
+	data.size = strlen(data.data);
+
+	switch (db->client->get(db->client, NULL, &key, &data, DB_GET_BOTH)) {
+	case DB_NOTFOUND:
+		result = ISC_R_NOTFOUND;
+		break;
+	case 0:
+		result = ISC_R_SUCCESS;
+		break;
+	default:
+		result = ISC_R_FAILURE;
+	}
+
+xfr_cleanup:
+
+	/* free any memory duplicate string in the key field */
+	if (key.data != NULL) {
+		free(key.data);
+	}
+
+	/* free any memory allocated to the data field. */
+	if (data.data != NULL) {
+		free(data.data);
+	}
+
+	return (result);
+}
+
+/*%
+ * BDB does not allow a secondary index on a database that allows
+ * duplicates.  We have a few options:
+ *
+ * 1) kill speed by having lookup method use a secondary db which
+ * is associated to the primary DB with the DNS data.  Then have
+ * another secondary db for zone transfer which also points to
+ * the dns_data primary.  NO - The  point of this driver is
+ * lookup performance.
+ *
+ * 2) Blow up database size by storing DNS data twice.  Once for
+ * the lookup (dns_data) database, and a second time for the zone
+ * transfer (dns_xfr) database. NO - That would probably require
+ * a larger cache to provide good performance.  Also, that would
+ * make the DB larger on disk potentially slowing it as well.
+ *
+ * 3) Loop through the dns_xfr database with a cursor to get
+ * all the different hosts in a zone.  Then use the zone & host
+ * together to lookup the data in the dns_data database. YES -
+ * This may slow down zone xfr's a little, but that's ok they
+ * don't happen as often and don't need to be as fast. We can
+ * also use this table when deleting a zone (The BDB driver
+ * is read only - the delete would be used during replication
+ * updates by a separate process).
+ */
+
+static isc_result_t
+bdbhpt_allnodes(const char *zone, void *driverarg, void *dbdata,
+		dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result = ISC_R_NOTFOUND;
+	bdbhpt_instance_t *db = (bdbhpt_instance_t *)dbdata;
+	DBC *xfr_cursor = NULL;
+	DBC *dns_cursor = NULL;
+	DBT xfr_key, xfr_data, dns_key, dns_data;
+	int xfr_flags;
+	int dns_flags;
+	int bdbhptres;
+	bdbhpt_parsed_data_t pd;
+	char *tmp = NULL, *tmp_zone, *tmp_zone_host = NULL;
+
+	UNUSED(driverarg);
+
+	memset(&xfr_key, 0, sizeof(DBT));
+	memset(&xfr_data, 0, sizeof(DBT));
+	memset(&dns_key, 0, sizeof(DBT));
+	memset(&dns_data, 0, sizeof(DBT));
+
+	xfr_key.data = tmp_zone = strdup(zone);
+	if (xfr_key.data == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	xfr_key.size = strlen(xfr_key.data);
+
+	/* get a cursor to loop through dns_xfr table */
+	if (db->xfr->cursor(db->xfr, NULL, &xfr_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto allnodes_cleanup;
+	}
+
+	/* get a cursor to loop through dns_data table */
+	if (db->data->cursor(db->data, NULL, &dns_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto allnodes_cleanup;
+	}
+
+	xfr_flags = DB_SET;
+
+	/* loop through xfr table for specified zone. */
+	while ((bdbhptres = xfr_cursor->c_get(xfr_cursor, &xfr_key, &xfr_data,
+					      xfr_flags)) == 0)
+	{
+		xfr_flags = DB_NEXT_DUP;
+
+		/* +1 to allow for space between zone and host names */
+		dns_key.size = xfr_data.size + xfr_key.size + 1;
+
+		/* +1 to allow for null term at end of string. */
+		dns_key.data = tmp_zone_host = malloc(dns_key.size + 1);
+		if (dns_key.data == NULL) {
+			goto allnodes_cleanup;
+		}
+
+		/*
+		 * construct search key for dns_data.
+		 * zone_name(a space)host_name
+		 */
+		strcpy(dns_key.data, zone);
+		strcat(dns_key.data, " ");
+		strncat(dns_key.data, xfr_data.data, xfr_data.size);
+
+		dns_flags = DB_SET;
+
+		while ((bdbhptres = dns_cursor->c_get(dns_cursor, &dns_key,
+						      &dns_data, dns_flags)) ==
+		       0)
+		{
+			dns_flags = DB_NEXT_DUP;
+
+			/* +1 to allow for null term at end of string. */
+			tmp = realloc(tmp, dns_data.size + 1);
+			if (tmp == NULL) {
+				goto allnodes_cleanup;
+			}
+
+			/* copy data to tmp string, and append null term. */
+			strncpy(tmp, dns_data.data, dns_data.size);
+			tmp[dns_data.size] = '\0';
+
+			/* split string into dns data parts. */
+			if (bdbhpt_parse_data(tmp, &pd) != ISC_R_SUCCESS) {
+				goto allnodes_cleanup;
+			}
+
+			result = dns_sdlz_putnamedrr(allnodes, pd.host, pd.type,
+						     pd.ttl, pd.data);
+			if (result != ISC_R_SUCCESS) {
+				goto allnodes_cleanup;
+			}
+		} /* end inner while loop */
+
+		/* clean up memory */
+		if (tmp_zone_host != NULL) {
+			free(tmp_zone_host);
+			tmp_zone_host = NULL;
+		}
+	} /* end outer while loop */
+
+allnodes_cleanup:
+
+	/* free any memory */
+	if (tmp != NULL) {
+		free(tmp);
+	}
+
+	if (tmp_zone_host != NULL) {
+		free(tmp_zone_host);
+	}
+
+	if (tmp_zone != NULL) {
+		free(tmp_zone);
+	}
+
+	/* get rid of cursors */
+	if (xfr_cursor != NULL) {
+		xfr_cursor->c_close(xfr_cursor);
+	}
+
+	if (dns_cursor != NULL) {
+		dns_cursor->c_close(dns_cursor);
+	}
+
+	return (result);
+}
+
+/*%
+ * Performs bdbhpt cleanup.
+ * Used by bdbhpt_create if there is an error starting up.
+ * Used by bdbhpt_destroy when the driver is shutting down.
+ */
+
+static void
+bdbhpt_cleanup(bdbhpt_instance_t *db) {
+	isc_mem_t *mctx;
+
+	/* close databases */
+	if (db->data != NULL) {
+		db->data->close(db->data, 0);
+	}
+	if (db->xfr != NULL) {
+		db->xfr->close(db->xfr, 0);
+	}
+	if (db->zone != NULL) {
+		db->zone->close(db->zone, 0);
+	}
+	if (db->client != NULL) {
+		db->client->close(db->client, 0);
+	}
+
+	/* close environment */
+	if (db->dbenv != NULL) {
+		db->dbenv->close(db->dbenv, 0);
+	}
+
+	/* cleanup memory */
+	if (db->mctx != NULL) {
+		/* save mctx for later */
+		mctx = db->mctx;
+		/* return, and detach the memory */
+		isc_mem_putanddetach(&mctx, db, sizeof(bdbhpt_instance_t));
+	}
+}
+
+static isc_result_t
+bdbhpt_findzone(void *driverarg, void *dbdata, const char *name,
+		dns_clientinfomethods_t *methods,
+		dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	bdbhpt_instance_t *db = (bdbhpt_instance_t *)dbdata;
+	DBT key, data;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	memset(&key, 0, sizeof(DBT));
+	memset(&data, 0, sizeof(DBT));
+	data.flags = DB_DBT_MALLOC;
+
+	key.data = strdup(name);
+
+	if (key.data == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	/*
+	 * reverse string to take advantage of BDB locality of reference
+	 * if we need further lookups because the zone doesn't match the
+	 * first time.
+	 */
+	key.data = bdbhpt_strrev(key.data);
+	key.size = strlen(key.data);
+
+	switch (db->zone->get(db->zone, NULL, &key, &data, 0)) {
+	case DB_NOTFOUND:
+		result = ISC_R_NOTFOUND;
+		break;
+	case 0:
+		result = ISC_R_SUCCESS;
+		break;
+	default:
+		result = ISC_R_FAILURE;
+	}
+
+	/* free any memory duplicate string in the key field */
+	if (key.data != NULL) {
+		free(key.data);
+	}
+
+	/* free any memory allocated to the data field. */
+	if (data.data != NULL) {
+		free(data.data);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+bdbhpt_lookup(const char *zone, const char *name, void *driverarg, void *dbdata,
+	      dns_sdlzlookup_t *lookup, dns_clientinfomethods_t *methods,
+	      dns_clientinfo_t *clientinfo) {
+	isc_result_t result = ISC_R_NOTFOUND;
+	bdbhpt_instance_t *db = (bdbhpt_instance_t *)dbdata;
+	DBC *data_cursor = NULL;
+	DBT key, data;
+	int bdbhptres;
+	int flags;
+
+	bdbhpt_parsed_data_t pd;
+	char *tmp = NULL;
+	char *keyStr = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	memset(&key, 0, sizeof(DBT));
+	memset(&data, 0, sizeof(DBT));
+
+	key.size = strlen(zone) + strlen(name) + 1;
+
+	/* allocate mem for key */
+	key.data = keyStr = malloc((key.size + 1) * sizeof(char));
+
+	if (keyStr == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	strcpy(keyStr, zone);
+	strcat(keyStr, " ");
+	strcat(keyStr, name);
+
+	/* get a cursor to loop through data */
+	if (db->data->cursor(db->data, NULL, &data_cursor, 0) != 0) {
+		result = ISC_R_FAILURE;
+		goto lookup_cleanup;
+	}
+
+	result = ISC_R_NOTFOUND;
+
+	flags = DB_SET;
+	while ((bdbhptres = data_cursor->c_get(data_cursor, &key, &data,
+					       flags)) == 0)
+	{
+		flags = DB_NEXT_DUP;
+		tmp = realloc(tmp, data.size + 1);
+		if (tmp == NULL) {
+			goto lookup_cleanup;
+		}
+
+		strncpy(tmp, data.data, data.size);
+		tmp[data.size] = '\0';
+
+		if (bdbhpt_parse_data(tmp, &pd) != ISC_R_SUCCESS) {
+			goto lookup_cleanup;
+		}
+
+		result = dns_sdlz_putrr(lookup, pd.type, pd.ttl, pd.data);
+
+		if (result != ISC_R_SUCCESS) {
+			goto lookup_cleanup;
+		}
+	} /* end while loop */
+
+lookup_cleanup:
+
+	/* get rid of cursor */
+	if (data_cursor != NULL) {
+		data_cursor->c_close(data_cursor);
+	}
+
+	free(keyStr);
+	if (tmp != NULL) {
+		free(tmp);
+	}
+
+	return (result);
+}
+
+/*% Initializes, sets flags and then opens Berkeley databases. */
+
+static isc_result_t
+bdbhpt_opendb(DB_ENV *db_env, DBTYPE db_type, DB **db, const char *db_name,
+	      char *db_file, int flags) {
+	int result;
+
+	/* Initialize the database. */
+	if ((result = db_create(db, db_env, 0)) != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt could not initialize %s database. "
+			      "bdbhpt error: %s",
+			      db_name, db_strerror(result));
+		return (ISC_R_FAILURE);
+	}
+
+	/* set database flags. */
+	if ((result = (*db)->set_flags(*db, flags)) != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt could not set flags for %s database. "
+			      "bdbhpt error: %s",
+			      db_name, db_strerror(result));
+		return (ISC_R_FAILURE);
+	}
+
+	/* open the database. */
+	if ((result = (*db)->open(*db, NULL, db_file, db_name, db_type,
+				  DB_RDONLY | bdbhpt_threads, 0)) != 0)
+	{
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt could not open %s database in %s. "
+			      "bdbhpt error: %s",
+			      db_name, db_file, db_strerror(result));
+		return (ISC_R_FAILURE);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+bdbhpt_create(const char *dlzname, unsigned int argc, char *argv[],
+	      void *driverarg, void **dbdata) {
+	isc_result_t result;
+	int bdbhptres;
+	int bdbFlags = 0;
+	bdbhpt_instance_t *db = NULL;
+
+	UNUSED(dlzname);
+	UNUSED(driverarg);
+
+	/* verify we have 4 arg's passed to the driver */
+	if (argc != 4) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt driver requires at least "
+			      "3 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	switch ((char)*argv[1]) {
+	/*
+	 * Transactional mode.  Highest safety - lowest speed.
+	 */
+	case 'T':
+	case 't':
+		bdbFlags = DB_INIT_MPOOL | DB_INIT_LOCK | DB_INIT_LOG |
+			   DB_INIT_TXN;
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
+			      "bdbhpt driver using transactional mode.");
+		break;
+	/*
+	 * Concurrent mode.  Lower safety (no rollback) -
+	 * higher speed.
+	 */
+	case 'C':
+	case 'c':
+		bdbFlags = DB_INIT_CDB | DB_INIT_MPOOL;
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
+			      "bdbhpt driver using concurrent mode.");
+		break;
+	/*
+	 * Private mode. No inter-process communication & no locking.
+	 * Lowest safety - highest speed.
+	 */
+	case 'P':
+	case 'p':
+		bdbFlags = DB_PRIVATE | DB_INIT_MPOOL;
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
+			      "bdbhpt driver using private mode.");
+		break;
+	default:
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt driver requires the operating mode "
+			      "be set to P or C or T.  You specified '%s'",
+			      argv[1]);
+		return (ISC_R_FAILURE);
+	}
+
+	/* allocate and zero memory for driver structure */
+	db = isc_mem_get(named_g_mctx, sizeof(bdbhpt_instance_t));
+	memset(db, 0, sizeof(bdbhpt_instance_t));
+
+	/* attach to the memory context */
+	isc_mem_attach(named_g_mctx, &db->mctx);
+
+	/*
+	 * create bdbhpt environment
+	 * Basically bdbhpt allocates and assigns memory to db->dbenv
+	 */
+	bdbhptres = db_env_create(&db->dbenv, 0);
+	if (bdbhptres != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt environment could not be created. "
+			      "bdbhpt error: %s",
+			      db_strerror(bdbhptres));
+		result = ISC_R_FAILURE;
+		goto init_cleanup;
+	}
+
+	/* open bdbhpt environment */
+	bdbhptres = db->dbenv->open(db->dbenv, argv[2],
+				    bdbFlags | bdbhpt_threads | DB_CREATE, 0);
+	if (bdbhptres != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "bdbhpt environment at '%s' could not be opened."
+			      " bdbhpt error: %s",
+			      argv[2], db_strerror(bdbhptres));
+		result = ISC_R_FAILURE;
+		goto init_cleanup;
+	}
+
+	/* open dlz_data database. */
+	result = bdbhpt_opendb(db->dbenv, DB_UNKNOWN, &db->data, dlz_data,
+			       argv[3], DB_DUP | DB_DUPSORT);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* open dlz_xfr database. */
+	result = bdbhpt_opendb(db->dbenv, DB_UNKNOWN, &db->xfr, dlz_xfr,
+			       argv[3], DB_DUP | DB_DUPSORT);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* open dlz_zone database. */
+	result = bdbhpt_opendb(db->dbenv, DB_UNKNOWN, &db->zone, dlz_zone,
+			       argv[3], 0);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	/* open dlz_client database. */
+	result = bdbhpt_opendb(db->dbenv, DB_UNKNOWN, &db->client, dlz_client,
+			       argv[3], DB_DUP | DB_DUPSORT);
+	if (result != ISC_R_SUCCESS) {
+		goto init_cleanup;
+	}
+
+	*dbdata = db;
+
+	return (ISC_R_SUCCESS);
+
+init_cleanup:
+
+	bdbhpt_cleanup(db);
+	return (result);
+}
+
+static void
+bdbhpt_destroy(void *driverarg, void *dbdata) {
+	UNUSED(driverarg);
+
+	bdbhpt_cleanup((bdbhpt_instance_t *)dbdata);
+}
+
+/*
+ * bdbhpt_authority not needed as authority data is returned by lookup
+ */
+static dns_sdlzmethods_t dlz_bdbhpt_methods = {
+	bdbhpt_create,
+	bdbhpt_destroy,
+	bdbhpt_findzone,
+	bdbhpt_lookup,
+	NULL,
+	bdbhpt_allnodes,
+	bdbhpt_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_bdbhpt_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ bdbhpt driver.");
+
+	result = dns_sdlzregister("bdbhpt", &dlz_bdbhpt_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA |
+					  DNS_SDLZFLAG_THREADSAFE,
+				  named_g_mctx, &dlz_bdbhpt);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_bdbhpt_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ bdbhpt driver.");
+
+	if (dlz_bdbhpt != NULL) {
+		dns_sdlzunregister(&dlz_bdbhpt);
+	}
+}
+
+#endif /* ifdef DLZ_BDB */
diff --git a/contrib/dlz/drivers/dlz_dlopen_driver.c b/contrib/dlz/drivers/dlz_dlopen_driver.c
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_dlopen_driver.c
diff --git a/contrib/dlz/drivers/dlz_drivers.c b/contrib/dlz/drivers/dlz_drivers.c
new file mode 100644
index 0000000..8320bf8
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_drivers.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2005  Internet Systems Consortium, Inc. ("ISC")
+ * 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 <isc/result.h>
+
+/*
+ * Pull in declarations for this module's functions.
+ */
+
+#include <dlz/dlz_drivers.h>
+
+/*
+ * Pull in driver-specific stuff.
+ */
+
+#ifdef DLZ_STUB
+#include <dlz/dlz_stub_driver.h>
+#endif /* ifdef DLZ_STUB */
+
+#ifdef DLZ_POSTGRES
+#include <dlz/dlz_postgres_driver.h>
+#endif /* ifdef DLZ_POSTGRES */
+
+#ifdef DLZ_MYSQL
+#include <dlz/dlz_mysql_driver.h>
+#endif /* ifdef DLZ_MYSQL */
+
+#ifdef DLZ_FILESYSTEM
+#include <dlz/dlz_filesystem_driver.h>
+#endif /* ifdef DLZ_FILESYSTEM */
+
+#ifdef DLZ_BDB
+#include <dlz/dlz_bdb_driver.h>
+#include <dlz/dlz_bdbhpt_driver.h>
+#endif /* ifdef DLZ_BDB */
+
+#ifdef DLZ_LDAP
+#include <dlz/dlz_ldap_driver.h>
+#endif /* ifdef DLZ_LDAP */
+
+#ifdef DLZ_ODBC
+#include <dlz/dlz_odbc_driver.h>
+#endif /* ifdef DLZ_ODBC */
+
+/*%
+ * Call init functions for all relevant DLZ drivers.
+ */
+
+isc_result_t
+dlz_drivers_init(void) {
+	isc_result_t result = ISC_R_SUCCESS;
+
+#ifdef DLZ_STUB
+	result = dlz_stub_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_STUB */
+
+#ifdef DLZ_POSTGRES
+	result = dlz_postgres_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_POSTGRES */
+
+#ifdef DLZ_MYSQL
+	result = dlz_mysql_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_MYSQL */
+
+#ifdef DLZ_FILESYSTEM
+	result = dlz_fs_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_FILESYSTEM */
+
+#ifdef DLZ_BDB
+	result = dlz_bdb_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+	result = dlz_bdbhpt_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_BDB */
+
+#ifdef DLZ_LDAP
+	result = dlz_ldap_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_LDAP */
+
+#ifdef DLZ_ODBC
+	result = dlz_odbc_init();
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+#endif /* ifdef DLZ_ODBC */
+
+	return (result);
+}
+
+/*%
+ * Call shutdown functions for all relevant DLZ drivers.
+ */
+
+void
+dlz_drivers_clear(void) {
+#ifdef DLZ_STUB
+	dlz_stub_clear();
+#endif /* ifdef DLZ_STUB */
+
+#ifdef DLZ_POSTGRES
+	dlz_postgres_clear();
+#endif /* ifdef DLZ_POSTGRES */
+
+#ifdef DLZ_MYSQL
+	dlz_mysql_clear();
+#endif /* ifdef DLZ_MYSQL */
+
+#ifdef DLZ_FILESYSTEM
+	dlz_fs_clear();
+#endif /* ifdef DLZ_FILESYSTEM */
+
+#ifdef DLZ_BDB
+	dlz_bdb_clear();
+	dlz_bdbhpt_clear();
+#endif /* ifdef DLZ_BDB */
+
+#ifdef DLZ_LDAP
+	dlz_ldap_clear();
+#endif /* ifdef DLZ_LDAP */
+
+#ifdef DLZ_ODBC
+	dlz_odbc_clear();
+#endif /* ifdef DLZ_ODBC */
+}
diff --git a/contrib/dlz/drivers/dlz_filesystem_driver.c b/contrib/dlz/drivers/dlz_filesystem_driver.c
new file mode 100644
index 0000000..c097411
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_filesystem_driver.c
@@ -0,0 +1,1000 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_FILESYSTEM
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include <isc/dir.h>
+#include <isc/mem.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_filesystem_driver.h>
+#include <named/globals.h>
+
+static dns_sdlzimplementation_t *dlz_fs = NULL;
+
+typedef struct config_data {
+	char *basedir;
+	int basedirsize;
+	char *datadir;
+	int datadirsize;
+	char *xfrdir;
+	int xfrdirsize;
+	int splitcnt;
+	char separator;
+	char pathsep;
+	isc_mem_t *mctx;
+} config_data_t;
+
+typedef struct dir_entry dir_entry_t;
+
+struct dir_entry {
+	char dirpath[PATH_MAX];
+	ISC_LINK(dir_entry_t) link;
+};
+
+typedef ISC_LIST(dir_entry_t) dlist_t;
+
+/* forward reference */
+
+static void
+fs_destroy(void *driverarg, void *dbdata);
+
+/*
+ * Private methods
+ */
+
+static bool
+is_safe(const char *input) {
+	unsigned int i;
+	unsigned int len = strlen(input);
+
+	/* check that only allowed characters  are in the domain name */
+	for (i = 0; i < len; i++) {
+		/* '.' is allowed, but has special requirements */
+		if (input[i] == '.') {
+			/* '.' is not allowed as first char */
+			if (i == 0) {
+				return (false);
+			}
+			/* '..', two dots together is not allowed. */
+			if (input[i - 1] == '.') {
+				return (false);
+			}
+			/* '.' is not allowed as last char */
+			if (i == len - 1) {
+				return (false);
+			}
+			/* only 1 dot in ok location, continue at next char */
+			continue;
+		}
+		/* '-' is allowed, continue at next char */
+		if (input[i] == '-') {
+			continue;
+		}
+		/* 0-9 is allowed, continue at next char */
+		if (input[i] >= '0' && input[i] <= '9') {
+			continue;
+		}
+		/* A-Z uppercase is allowed, continue at next char */
+		if (input[i] >= 'A' && input[i] <= 'Z') {
+			continue;
+		}
+		/* a-z lowercase is allowed, continue at next char */
+		if (input[i] >= 'a' && input[i] <= 'z') {
+			continue;
+		}
+
+		/*
+		 * colon needs to be allowed for IPV6 client
+		 * addresses.  Not dangerous in domain names, as not a
+		 * special char.
+		 */
+		if (input[i] == ':') {
+			continue;
+		}
+
+		/*
+		 * '@' needs to be allowed for in zone data.  Not
+		 * dangerous in domain names, as not a special char.
+		 */
+		if (input[i] == '@') {
+			continue;
+		}
+
+		/*
+		 * if we reach this point we have encountered a
+		 * disallowed char!
+		 */
+		return (false);
+	}
+	/* everything ok. */
+	return (true);
+}
+
+static void
+create_path_helper(char *out, const char *in, config_data_t *cd) {
+	char *tmpString;
+	char *tmpPtr;
+	int i;
+
+	tmpString = isc_mem_strdup(named_g_mctx, in);
+
+	/*
+	 * don't forget is_safe guarantees '.' will NOT be the
+	 * first/last char
+	 */
+	while ((tmpPtr = strrchr(tmpString, '.')) != NULL) {
+		i = 0;
+		while (tmpPtr[i + 1] != '\0') {
+			if (cd->splitcnt < 1) {
+				strcat(out, (char *)&tmpPtr[i + 1]);
+			} else {
+				strncat(out, (char *)&tmpPtr[i + 1],
+					cd->splitcnt);
+			}
+			strncat(out, (char *)&cd->pathsep, 1);
+			if (cd->splitcnt == 0) {
+				break;
+			}
+			if (strlen((char *)&tmpPtr[i + 1]) <=
+			    (unsigned int)cd->splitcnt)
+			{
+				break;
+			}
+			i += cd->splitcnt;
+		}
+		tmpPtr[0] = '\0';
+	}
+
+	/* handle the "first" label properly */
+	i = 0;
+	tmpPtr = tmpString;
+	while (tmpPtr[i] != '\0') {
+		if (cd->splitcnt < 1) {
+			strcat(out, (char *)&tmpPtr[i]);
+		} else {
+			strncat(out, (char *)&tmpPtr[i], cd->splitcnt);
+		}
+		strncat(out, (char *)&cd->pathsep, 1);
+		if (cd->splitcnt == 0) {
+			break;
+		}
+		if (strlen((char *)&tmpPtr[i]) <= (unsigned int)cd->splitcnt) {
+			break;
+		}
+		i += cd->splitcnt;
+	}
+
+	isc_mem_free(named_g_mctx, tmpString);
+}
+
+/*%
+ * Checks to make sure zone and host are safe.  If safe, then
+ * hashes zone and host strings to build a path.  If zone / host
+ * are not safe an error is returned.
+ */
+
+static isc_result_t
+create_path(const char *zone, const char *host, const char *client,
+	    config_data_t *cd, char **path) {
+	char *tmpPath;
+	int pathsize;
+	int len;
+	bool isroot = false;
+
+	/* we require a zone & cd parameter */
+	REQUIRE(zone != NULL);
+	REQUIRE(cd != NULL);
+	/* require path to be a pointer to NULL */
+	REQUIRE(path != NULL && *path == NULL);
+	/*
+	 * client and host may both be NULL, but they can't both be
+	 * NON-NULL
+	 */
+	REQUIRE((host == NULL && client == NULL) ||
+		(host != NULL && client == NULL) ||
+		(host == NULL && client != NULL));
+
+	/* special case for root zone */
+	if (strcmp(zone, ".") == 0) {
+		isroot = true;
+	}
+
+	/* if the requested zone is "unsafe", return error */
+	if (!isroot && !is_safe(zone)) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* if host was passed, verify that it is safe */
+	if (host != NULL && !is_safe(host)) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* if client was passed, verify that it is safe */
+	if (client != NULL && !is_safe(client)) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* Determine how much memory the split up string will require */
+	if (host != NULL) {
+		len = strlen(zone) + strlen(host);
+	} else if (client != NULL) {
+		len = strlen(zone) + strlen(client);
+	} else {
+		len = strlen(zone);
+	}
+
+	/*
+	 * even though datadir and xfrdir will never be in the same
+	 * string we only waste a few bytes by allocating for both,
+	 * and then we are safe from buffer overruns.
+	 */
+	pathsize = len + cd->basedirsize + cd->datadirsize + cd->xfrdirsize + 4;
+
+	/* if we are splitting names, we will need extra space. */
+	if (cd->splitcnt > 0) {
+		pathsize += len / cd->splitcnt;
+	}
+
+	tmpPath = isc_mem_allocate(named_g_mctx, pathsize * sizeof(char));
+
+	/*
+	 * build path string.
+	 * start out with base directory.
+	 */
+	strcpy(tmpPath, cd->basedir);
+
+	/* add zone name - parsed properly */
+	if (!isroot) {
+		create_path_helper(tmpPath, zone, cd);
+	}
+
+	/*
+	 * When neither client or host is passed we are building a
+	 * path to see if a zone is supported.  We require that a zone
+	 * path have the "data dir" directory contained within it so
+	 * that we know this zone is really supported.  Otherwise,
+	 * this zone may not really be supported because we are
+	 * supporting a delagated sub zone.
+	 *
+	 * Example:
+	 *
+	 * We are supporting long.domain.com and using a splitcnt of
+	 * 0.  the base dir is "/base-dir/" and the data dir is
+	 * "/.datadir" We want to see if we are authoritative for
+	 * domain.com.  Path /base-dir/com/domain/.datadir since
+	 * /base-dir/com/domain/.datadir does not exist, we are not
+	 * authoritative for the domain "domain.com".  However we are
+	 * authoritative for the domain "long.domain.com" because the
+	 * path /base-dir/com/domain/long/.datadir does exist!
+	 */
+
+	/* if client is passed append xfr dir, otherwise append data dir */
+	if (client != NULL) {
+		strcat(tmpPath, cd->xfrdir);
+		strncat(tmpPath, (char *)&cd->pathsep, 1);
+		strcat(tmpPath, client);
+	} else {
+		strcat(tmpPath, cd->datadir);
+	}
+
+	/* if host not null, add it. */
+	if (host != NULL) {
+		strncat(tmpPath, (char *)&cd->pathsep, 1);
+		create_path_helper(tmpPath, host, cd);
+	}
+
+	/* return the path we built. */
+	*path = tmpPath;
+
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+process_dir(isc_dir_t *dir, void *passback, config_data_t *cd,
+	    dlist_t *dir_list, unsigned int basedirlen) {
+	char tmp[PATH_MAX + NAME_MAX];
+	int astPos;
+	struct stat sb;
+	isc_result_t result = ISC_R_FAILURE;
+	char *endp;
+	char *type;
+	char *ttlStr;
+	char *data;
+	char host[NAME_MAX];
+	char *tmpString;
+	char *tmpPtr;
+	int ttl;
+	int i;
+	int len;
+	dir_entry_t *direntry;
+	bool foundHost;
+
+	tmp[0] = '\0'; /* set 1st byte to '\0' so strcpy works right. */
+	host[0] = '\0';
+	foundHost = false;
+
+	/* copy base directory name to tmp. */
+	strcpy(tmp, dir->dirname);
+
+	/* dir->dirname will always have '*' as the last char. */
+	astPos = strlen(dir->dirname) - 1;
+
+	/* if dir_list != NULL, were are performing a zone xfr */
+	if (dir_list != NULL) {
+		/* if splitcnt == 0, determine host from path. */
+		if (cd->splitcnt == 0) {
+			if (strlen(tmp) - 3 > basedirlen) {
+				tmp[astPos - 1] = '\0';
+				tmpString = (char *)&tmp[basedirlen + 1];
+				/* handle filesystem's special wildcard "-"  */
+				if (strcmp(tmpString, "-") == 0) {
+					strcpy(host, "*");
+				} else {
+					/*
+					 * not special wildcard -- normal name
+					 */
+					while ((tmpPtr = strrchr(
+							tmpString,
+							cd->pathsep)) != NULL)
+					{
+						if ((strlen(host) +
+						     strlen(tmpPtr + 1) + 2) >
+						    NAME_MAX)
+						{
+							continue;
+						}
+						strcat(host, tmpPtr + 1);
+						strcat(host, ".");
+						tmpPtr[0] = '\0';
+					}
+					if ((strlen(host) + strlen(tmpString) +
+					     1) <= NAME_MAX)
+					{
+						strcat(host, tmpString);
+					}
+				}
+
+				foundHost = true;
+				/* set tmp again for use later */
+				strcpy(tmp, dir->dirname);
+			}
+		} else {
+			/*
+			 * if splitcnt != 0 determine host from
+			 * ".host" directory entry
+			 */
+			while (isc_dir_read(dir) == ISC_R_SUCCESS) {
+				if (strncasecmp(".host", dir->entry.name, 5) ==
+				    0)
+				{
+					/*
+					 * handle filesystem's special
+					 * wildcard "-"
+					 */
+					if (strcmp((char *)&dir->entry.name[6],
+						   "-") == 0)
+					{
+						strlcpy(host, "*",
+							sizeof(host));
+					} else {
+						strlcpy(host,
+							(char *)&dir->entry
+								.name[6],
+							sizeof(host));
+					}
+					foundHost = true;
+					break;
+				}
+			}
+			/* reset dir list for use later */
+			isc_dir_reset(dir);
+		} /* end of else */
+	}
+
+	while (isc_dir_read(dir) == ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
+			      "Filesystem driver Dir name:"
+			      " '%s' Dir entry: '%s'\n",
+			      dir->dirname, dir->entry.name);
+
+		/* skip any entries starting with "." */
+		if (dir->entry.name[0] == '.') {
+			continue;
+		}
+
+		/*
+		 * get rid of '*', set to NULL.  Effectively trims
+		 * string from previous loop to base directory only
+		 * while still leaving memory for concat to be
+		 * performed next.
+		 */
+
+		tmp[astPos] = '\0';
+
+		/* add name to base directory name. */
+		strcat(tmp, dir->entry.name);
+
+		/* make sure we can stat entry */
+		if (stat(tmp, &sb) == 0) {
+			/* if entry is a directory */
+			if ((sb.st_mode & S_IFDIR) != 0) {
+				/*
+				 * if dir list is NOT NULL, add dir to
+				 * dir list
+				 */
+				if (dir_list != NULL) {
+					direntry = isc_mem_get(
+						named_g_mctx,
+						sizeof(dir_entry_t));
+					strcpy(direntry->dirpath, tmp);
+					ISC_LINK_INIT(direntry, link);
+					ISC_LIST_APPEND(*dir_list, direntry,
+							link);
+					result = ISC_R_SUCCESS;
+				}
+				continue;
+
+				/*
+				 * if entry is a file be sure we do
+				 * not add entry to DNS results if we
+				 * are performing a zone xfr and we
+				 * could not find a host entry.
+				 */
+			} else if (dir_list != NULL && !foundHost) {
+				continue;
+			}
+		} else { /* if we cannot stat entry, skip it. */
+			continue;
+		}
+
+		type = dir->entry.name;
+		ttlStr = strchr(type, cd->separator);
+		if (ttlStr == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Filesystem driver: "
+				      "%s could not be parsed properly",
+				      tmp);
+			return (ISC_R_FAILURE);
+		}
+
+		/* replace separator char with NULL to split string */
+		ttlStr[0] = '\0';
+		/* start string after NULL of previous string */
+		ttlStr = (char *)&ttlStr[1];
+
+		data = strchr(ttlStr, cd->separator);
+		if (data == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Filesystem driver: "
+				      "%s could not be parsed properly",
+				      tmp);
+			return (ISC_R_FAILURE);
+		}
+
+		/* replace separator char with NULL to split string */
+		data[0] = '\0';
+
+		/* start string after NULL of previous string */
+		data = (char *)&data[1];
+
+		/* replace all cd->separator chars with a space. */
+		len = strlen(data);
+
+		for (i = 0; i < len; i++) {
+			if (data[i] == cd->separator) {
+				data[i] = ' ';
+			}
+		}
+
+		/* convert text to int, make sure it worked right */
+		ttl = strtol(ttlStr, &endp, 10);
+		if (*endp != '\0' || ttl < 0) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Filesystem driver "
+				      "ttl must be a positive number");
+		}
+
+		/* pass data back to Bind */
+		if (dir_list == NULL) {
+			result = dns_sdlz_putrr((dns_sdlzlookup_t *)passback,
+						type, ttl, data);
+		} else {
+			result = dns_sdlz_putnamedrr(
+				(dns_sdlzallnodes_t *)passback, (char *)host,
+				type, ttl, data);
+		}
+
+		/* if error, return error right away */
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+	} /* end of while loop */
+
+	return (result);
+}
+
+/*
+ * SDLZ interface methods
+ */
+
+static isc_result_t
+fs_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		const char *client) {
+	isc_result_t result;
+	char *path;
+	struct stat sb;
+	config_data_t *cd;
+	path = NULL;
+
+	UNUSED(driverarg);
+
+	cd = (config_data_t *)dbdata;
+
+	if (create_path(name, NULL, client, cd, &path) != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	if (stat(path, &sb) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto complete_AXFR;
+	}
+
+	if ((sb.st_mode & S_IFREG) != 0) {
+		result = ISC_R_SUCCESS;
+		goto complete_AXFR;
+	}
+
+	result = ISC_R_NOTFOUND;
+
+complete_AXFR:
+	isc_mem_free(named_g_mctx, path);
+	return (result);
+}
+
+static isc_result_t
+fs_allnodes(const char *zone, void *driverarg, void *dbdata,
+	    dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result;
+	dlist_t *dir_list;
+	config_data_t *cd;
+	char *basepath;
+	unsigned int basepathlen;
+	struct stat sb;
+	isc_dir_t dir;
+	dir_entry_t *dir_entry;
+	dir_entry_t *next_de;
+
+	basepath = NULL;
+	dir_list = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(allnodes);
+
+	cd = (config_data_t *)dbdata;
+
+	/* allocate memory for list */
+	dir_list = isc_mem_get(named_g_mctx, sizeof(dlist_t));
+
+	/* initialize list */
+	ISC_LIST_INIT(*dir_list);
+
+	if (create_path(zone, NULL, NULL, cd, &basepath) != ISC_R_SUCCESS) {
+		result = ISC_R_NOTFOUND;
+		goto complete_allnds;
+	}
+
+	/* remove path separator at end of path so stat works properly */
+	basepathlen = strlen(basepath);
+
+	if (stat(basepath, &sb) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto complete_allnds;
+	}
+
+	if ((sb.st_mode & S_IFDIR) == 0) {
+		result = ISC_R_NOTFOUND;
+		goto complete_allnds;
+	}
+
+	/* initialize and open directory */
+	isc_dir_init(&dir);
+	result = isc_dir_open(&dir, basepath);
+
+	/* if directory open failed, return error. */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Unable to open %s directory to read entries.",
+			      basepath);
+		result = ISC_R_FAILURE;
+		goto complete_allnds;
+	}
+
+	/* process the directory */
+	result = process_dir(&dir, allnodes, cd, dir_list, basepathlen);
+
+	/* close the directory */
+	isc_dir_close(&dir);
+
+	if (result != ISC_R_SUCCESS) {
+		goto complete_allnds;
+	}
+
+	/* get first dir entry from list. */
+	dir_entry = ISC_LIST_HEAD(*dir_list);
+	while (dir_entry != NULL) {
+		result = isc_dir_open(&dir, dir_entry->dirpath);
+		/* if directory open failed, return error. */
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Unable to open %s "
+				      "directory to read entries.",
+				      basepath);
+			result = ISC_R_FAILURE;
+			goto complete_allnds;
+		}
+
+		/* process the directory */
+		result = process_dir(&dir, allnodes, cd, dir_list, basepathlen);
+
+		/* close the directory */
+		isc_dir_close(&dir);
+
+		if (result != ISC_R_SUCCESS) {
+			goto complete_allnds;
+		}
+
+		dir_entry = ISC_LIST_NEXT(dir_entry, link);
+	} /* end while */
+
+complete_allnds:
+	/* clean up entries from list. */
+	dir_entry = ISC_LIST_HEAD(*dir_list);
+	while (dir_entry != NULL) {
+		next_de = ISC_LIST_NEXT(dir_entry, link);
+		isc_mem_put(named_g_mctx, dir_entry, sizeof(dir_entry_t));
+		dir_entry = next_de;
+	} /* end while */
+	isc_mem_put(named_g_mctx, dir_list, sizeof(dlist_t));
+
+	if (basepath != NULL) {
+		isc_mem_free(named_g_mctx, basepath);
+	}
+
+	return (result);
+}
+
+static isc_result_t
+fs_findzone(void *driverarg, void *dbdata, const char *name,
+	    dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	char *path;
+	struct stat sb;
+	path = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	if (create_path(name, NULL, NULL, (config_data_t *)dbdata, &path) !=
+	    ISC_R_SUCCESS)
+	{
+		return (ISC_R_NOTFOUND);
+	}
+
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1),
+		      "Filesystem driver Findzone() Checking for path: '%s'\n",
+		      path);
+
+	if (stat(path, &sb) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto complete_FZ;
+	}
+
+	if ((sb.st_mode & S_IFDIR) != 0) {
+		result = ISC_R_SUCCESS;
+		goto complete_FZ;
+	}
+
+	result = ISC_R_NOTFOUND;
+
+complete_FZ:
+
+	isc_mem_free(named_g_mctx, path);
+	return (result);
+}
+
+static isc_result_t
+fs_lookup(const char *zone, const char *name, void *driverarg, void *dbdata,
+	  dns_sdlzlookup_t *lookup, dns_clientinfomethods_t *methods,
+	  dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	char *path;
+	struct stat sb;
+	isc_dir_t dir;
+	path = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(lookup);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	if (strcmp(name, "*") == 0) {
+		/*
+		 * handle filesystem's special wildcard "-"
+		 */
+		result = create_path(zone, "-", NULL, (config_data_t *)dbdata,
+				     &path);
+	} else {
+		result = create_path(zone, name, NULL, (config_data_t *)dbdata,
+				     &path);
+	}
+
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	/* remove path separator at end of path so stat works properly */
+	path[strlen(path) - 1] = '\0';
+
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1),
+		      "Filesystem driver lookup() Checking for path: '%s'\n",
+		      path);
+
+	if (stat(path, &sb) != 0) {
+		result = ISC_R_NOTFOUND;
+		goto complete_lkup;
+	}
+
+	if ((sb.st_mode & S_IFDIR) == 0) {
+		result = ISC_R_NOTFOUND;
+		goto complete_lkup;
+	}
+
+	/* initialize and open directory */
+	isc_dir_init(&dir);
+	result = isc_dir_open(&dir, path);
+
+	/* if directory open failed, return error. */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Unable to open %s directory to read entries.",
+			      path);
+		result = ISC_R_FAILURE;
+		goto complete_lkup;
+	}
+
+	/* process any records in the directory */
+	result = process_dir(&dir, lookup, (config_data_t *)dbdata, NULL, 0);
+
+	/* close the directory */
+	isc_dir_close(&dir);
+
+complete_lkup:
+
+	isc_mem_free(named_g_mctx, path);
+	return (result);
+}
+
+static isc_result_t
+fs_create(const char *dlzname, unsigned int argc, char *argv[], void *driverarg,
+	  void **dbdata) {
+	config_data_t *cd;
+	char *endp;
+	int len;
+	char pathsep;
+
+	UNUSED(driverarg);
+	UNUSED(dlzname);
+
+	/* we require 5 command line args. */
+	if (argc != 6) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Filesystem driver requires "
+			      "6 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	if (strlen(argv[5]) > 1) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Filesystem driver can only "
+			      "accept a single character for separator.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* verify base dir ends with '/' or '\' */
+	len = strlen(argv[1]);
+	if (argv[1][len - 1] != '\\' && argv[1][len - 1] != '/') {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Base dir parameter for filesystem driver "
+			      "should end with %s",
+			      "either '/' or '\\' ");
+		return (ISC_R_FAILURE);
+	}
+
+	/* determine and save path separator for later */
+	if (argv[1][len - 1] == '\\') {
+		pathsep = '\\';
+	} else {
+		pathsep = '/';
+	}
+
+	/* allocate memory for our config data */
+	cd = isc_mem_get(named_g_mctx, sizeof(config_data_t));
+
+	/* zero the memory */
+	memset(cd, 0, sizeof(config_data_t));
+
+	cd->pathsep = pathsep;
+
+	/* get and store our base directory */
+	cd->basedir = isc_mem_strdup(named_g_mctx, argv[1]);
+	cd->basedirsize = strlen(cd->basedir);
+
+	/* get and store our data sub-dir */
+	cd->datadir = isc_mem_strdup(named_g_mctx, argv[2]);
+	cd->datadirsize = strlen(cd->datadir);
+
+	/* get and store our zone xfr sub-dir */
+	cd->xfrdir = isc_mem_strdup(named_g_mctx, argv[3]);
+	cd->xfrdirsize = strlen(cd->xfrdir);
+
+	/* get and store our directory split count */
+	cd->splitcnt = strtol(argv[4], &endp, 10);
+	if (*endp != '\0' || cd->splitcnt < 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Directory split count must be zero (0) "
+			      "or a positive number");
+	}
+
+	/* get and store our separator character */
+	cd->separator = *argv[5];
+
+	/* attach config data to memory context */
+	isc_mem_attach(named_g_mctx, &cd->mctx);
+
+	/* pass back config data */
+	*dbdata = cd;
+
+	/* return success */
+	return (ISC_R_SUCCESS);
+}
+
+static void
+fs_destroy(void *driverarg, void *dbdata) {
+	isc_mem_t *mctx;
+	config_data_t *cd;
+
+	UNUSED(driverarg);
+
+	cd = (config_data_t *)dbdata;
+
+	/*
+	 * free memory for each section of config data that was
+	 * allocated
+	 */
+	if (cd->basedir != NULL) {
+		isc_mem_free(named_g_mctx, cd->basedir);
+	}
+
+	if (cd->datadir != NULL) {
+		isc_mem_free(named_g_mctx, cd->datadir);
+	}
+
+	if (cd->xfrdir != NULL) {
+		isc_mem_free(named_g_mctx, cd->xfrdir);
+	}
+
+	/* hold memory context to use later */
+	mctx = cd->mctx;
+
+	/* free config data memory */
+	isc_mem_putanddetach(&mctx, cd, sizeof(config_data_t));
+}
+
+static dns_sdlzmethods_t dlz_fs_methods = {
+	fs_create,
+	fs_destroy,
+	fs_findzone,
+	fs_lookup,
+	NULL,
+	fs_allnodes,
+	fs_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_fs_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ filesystem driver.");
+
+	result = dns_sdlzregister("filesystem", &dlz_fs_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA,
+				  named_g_mctx, &dlz_fs);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_fs_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ filesystem driver.");
+
+	if (dlz_fs != NULL) {
+		dns_sdlzunregister(&dlz_fs);
+	}
+}
+
+#endif /* ifdef DLZ_FILESYSTEM */
diff --git a/contrib/dlz/drivers/dlz_ldap_driver.c b/contrib/dlz/drivers/dlz_ldap_driver.c
new file mode 100644
index 0000000..072d285
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_ldap_driver.c
@@ -0,0 +1,1216 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_LDAP
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_ldap_driver.h>
+#include <dlz/sdlz_helper.h>
+#include <named/globals.h>
+
+/*
+ * Need older API functions from ldap.h.
+ */
+#define LDAP_DEPRECATED 1
+
+#include <ldap.h>
+
+#define SIMPLE "simple"
+#define KRB41  "krb41"
+#define KRB42  "krb42"
+#define V2     "v2"
+#define V3     "v3"
+
+static dns_sdlzimplementation_t *dlz_ldap = NULL;
+
+#define dbc_search_limit 30
+#define ALLNODES	 1
+#define ALLOWXFR	 2
+#define AUTHORITY	 3
+#define FINDZONE	 4
+#define LOOKUP		 5
+
+/*%
+ * Structure to hold everything needed by this "instance" of the LDAP
+ * driver remember, the driver code is only loaded once, but may have
+ * many separate instances.
+ */
+
+typedef struct {
+	db_list_t *db; /*%< handle to a list of DB */
+	int method;    /*%< security authentication method */
+	char *user;    /*%< who is authenticating */
+	char *cred;    /*%< password for simple authentication method */
+	int protocol;  /*%< LDAP communication protocol version */
+	char *hosts;   /*%< LDAP server hosts */
+} ldap_instance_t;
+
+/* forward references */
+
+static isc_result_t
+dlz_ldap_findzone(void *driverarg, void *dbdata, const char *name,
+		  dns_clientinfomethods_t *methods,
+		  dns_clientinfo_t *clientinfo);
+
+static void
+dlz_ldap_destroy(void *driverarg, void *dbdata);
+
+/*
+ * Private methods
+ */
+
+/*% checks that the LDAP URL parameters make sense */
+static isc_result_t
+dlz_ldap_checkURL(char *URL, int attrCnt, const char *msg) {
+	isc_result_t result = ISC_R_SUCCESS;
+	int ldap_result;
+	LDAPURLDesc *ldap_url = NULL;
+
+	if (!ldap_is_ldap_url(URL)) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%s query is not a valid LDAP URL", msg);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	ldap_result = ldap_url_parse(URL, &ldap_url);
+	if (ldap_result != LDAP_SUCCESS || ldap_url == NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "parsing %s query failed", msg);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	if (ldap_count_values(ldap_url->lud_attrs) < attrCnt) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%s query must specify at least "
+			      "%d attributes to return",
+			      msg, attrCnt);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	if (ldap_url->lud_host != NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%s query must not specify a host", msg);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	if (ldap_url->lud_port != 389) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%s query must not specify a port", msg);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	if (ldap_url->lud_dn == NULL || strlen(ldap_url->lud_dn) < 1) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%s query must specify a search base", msg);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	if (ldap_url->lud_exts != NULL || ldap_url->lud_crit_exts != 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%s uses extensions. "
+			      "The driver does not support LDAP extensions.",
+			      msg);
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+cleanup:
+	if (ldap_url != NULL) {
+		ldap_free_urldesc(ldap_url);
+	}
+
+	return (result);
+}
+
+/*% Connects / reconnects to LDAP server */
+static isc_result_t
+dlz_ldap_connect(ldap_instance_t *dbi, dbinstance_t *dbc) {
+	isc_result_t result;
+	int ldap_result;
+
+	/* if we have a connection, get ride of it. */
+	if (dbc->dbconn != NULL) {
+		ldap_unbind_s((LDAP *)dbc->dbconn);
+		dbc->dbconn = NULL;
+	}
+
+	/* now connect / reconnect. */
+
+	/* initialize. */
+	dbc->dbconn = ldap_init(dbi->hosts, LDAP_PORT);
+	if (dbc->dbconn == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	/* set protocol version. */
+	ldap_result = ldap_set_option((LDAP *)dbc->dbconn,
+				      LDAP_OPT_PROTOCOL_VERSION,
+				      &(dbi->protocol));
+	if (ldap_result != LDAP_SUCCESS) {
+		result = ISC_R_NOPERM;
+		goto cleanup;
+	}
+
+	/* "bind" to server.  i.e. send username / pass */
+	ldap_result = ldap_bind_s((LDAP *)dbc->dbconn, dbi->user, dbi->cred,
+				  dbi->method);
+	if (ldap_result != LDAP_SUCCESS) {
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	return (ISC_R_SUCCESS);
+
+cleanup:
+
+	/* cleanup if failure. */
+	if (dbc->dbconn != NULL) {
+		ldap_unbind_s((LDAP *)dbc->dbconn);
+		dbc->dbconn = NULL;
+	}
+
+	return (result);
+}
+
+/*%
+ * Properly cleans up a list of database instances.
+ * This function is only used when the driver is compiled for
+ * multithreaded operation.
+ */
+static void
+ldap_destroy_dblist(db_list_t *dblist) {
+	dbinstance_t *ndbi = NULL;
+	dbinstance_t *dbi = NULL;
+
+	/* get the first DBI in the list */
+	ndbi = ISC_LIST_HEAD(*dblist);
+
+	/* loop through the list */
+	while (ndbi != NULL) {
+		dbi = ndbi;
+		/* get the next DBI in the list */
+		ndbi = ISC_LIST_NEXT(dbi, link);
+		/* release DB connection */
+		if (dbi->dbconn != NULL) {
+			ldap_unbind_s((LDAP *)dbi->dbconn);
+		}
+		/* release all memory that comprised a DBI */
+		destroy_sqldbinstance(dbi);
+	}
+	/* release memory for the list structure */
+	isc_mem_put(named_g_mctx, dblist, sizeof(db_list_t));
+}
+
+/*%
+ * Loops through the list of DB instances, attempting to lock
+ * on the mutex.  If successful, the DBI is reserved for use
+ * and the thread can perform queries against the database.
+ * If the lock fails, the next one in the list is tried.
+ * looping continues until a lock is obtained, or until
+ * the list has been searched dbc_search_limit times.
+ * This function is only used when the driver is compiled for
+ * multithreaded operation.
+ */
+static dbinstance_t *
+ldap_find_avail_conn(db_list_t *dblist) {
+	dbinstance_t *dbi = NULL;
+	dbinstance_t *head;
+	int count = 0;
+
+	/* get top of list */
+	head = dbi = ISC_LIST_HEAD(*dblist);
+
+	/* loop through list */
+	while (count < dbc_search_limit) {
+		/* try to lock on the mutex */
+		if (isc_mutex_trylock(&dbi->instance_lock) == ISC_R_SUCCESS) {
+			return (dbi); /* success, return the DBI for use. */
+		}
+		/* not successful, keep trying */
+		dbi = ISC_LIST_NEXT(dbi, link);
+
+		/* check to see if we have gone to the top of the list. */
+		if (dbi == NULL) {
+			count++;
+			dbi = head;
+		}
+	}
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_INFO,
+		      "LDAP driver unable to find available connection "
+		      "after searching %d times",
+		      count);
+	return (NULL);
+}
+
+static isc_result_t
+ldap_process_results(LDAP *dbc, LDAPMessage *msg, char **attrs, void *ptr,
+		     bool allnodes) {
+	isc_result_t result = ISC_R_SUCCESS;
+	int i = 0;
+	int j;
+	int len;
+	char *attribute = NULL;
+	LDAPMessage *entry;
+	char *endp = NULL;
+	char *host = NULL;
+	char *type = NULL;
+	char *data = NULL;
+	char **vals = NULL;
+	int ttl;
+
+	/* make sure there are at least some attributes to process. */
+	REQUIRE(attrs != NULL || attrs[0] != NULL);
+
+	/* get the first entry to process */
+	entry = ldap_first_entry(dbc, msg);
+	if (entry == NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
+			      "LDAP no entries to process.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* loop through all entries returned */
+	while (entry != NULL) {
+		/* reset for this loop */
+		ttl = 0;
+		len = 0;
+		i = 0;
+		attribute = attrs[i];
+
+		/* determine how much space we need for data string */
+		for (j = 0; attrs[j] != NULL; j++) {
+			/* get the list of values for this attribute. */
+			vals = ldap_get_values(dbc, entry, attrs[j]);
+			/* skip empty attributes. */
+			if (vals == NULL || ldap_count_values(vals) < 1) {
+				continue;
+			}
+			/*
+			 * we only use the first value.  this driver
+			 * does not support multi-valued attributes.
+			 */
+			len = len + strlen(vals[0]) + 1;
+			/* free vals for next loop */
+			ldap_value_free(vals);
+		} /* end for (j = 0; attrs[j] != NULL, j++) loop */
+
+		/* allocate memory for data string */
+		data = isc_mem_allocate(named_g_mctx, len + 1);
+
+		/*
+		 * Make sure data is null termed at the beginning so
+		 * we can check if any data was stored to it later.
+		 */
+		data[0] = '\0';
+
+		/* reset j to re-use below */
+		j = 0;
+
+		/* loop through the attributes in the order specified. */
+		while (attribute != NULL) {
+			/* get the list of values for this attribute. */
+			vals = ldap_get_values(dbc, entry, attribute);
+
+			/* skip empty attributes. */
+			if (vals == NULL || vals[0] == NULL) {
+				/* increment attribute pointer */
+				attribute = attrs[++i];
+				/* start loop over */
+				continue;
+			}
+
+			/*
+			 * j initially = 0.  Increment j each time we
+			 * set a field that way next loop will set
+			 * next field.
+			 */
+			switch (j) {
+			case 0:
+				j++;
+				/*
+				 * convert text to int, make sure it
+				 * worked right
+				 */
+				ttl = strtol(vals[0], &endp, 10);
+				if (*endp != '\0' || ttl < 0) {
+					isc_log_write(dns_lctx,
+						      DNS_LOGCATEGORY_DATABASE,
+						      DNS_LOGMODULE_DLZ,
+						      ISC_LOG_ERROR,
+						      "LDAP driver ttl must "
+						      "be a positive number");
+					goto cleanup;
+				}
+				break;
+			case 1:
+				j++;
+				type = isc_mem_strdup(named_g_mctx, vals[0]);
+				break;
+			case 2:
+				j++;
+				if (allnodes) {
+					host = isc_mem_strdup(named_g_mctx,
+							      vals[0]);
+				} else {
+					strcpy(data, vals[0]);
+				}
+				break;
+			case 3:
+				j++;
+				if (allnodes) {
+					strcpy(data, vals[0]);
+				} else {
+					strcat(data, " ");
+					strcat(data, vals[0]);
+				}
+				break;
+			default:
+				strcat(data, " ");
+				strcat(data, vals[0]);
+				break;
+			} /* end switch(j) */
+
+			/* free values */
+			ldap_value_free(vals);
+			vals = NULL;
+
+			/* increment attribute pointer */
+			attribute = attrs[++i];
+		} /* end while (attribute != NULL) */
+
+		if (type == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver unable "
+				      "to retrieve DNS type");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		if (strlen(data) < 1) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver unable "
+				      "to retrieve DNS data");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		if (allnodes && host != NULL) {
+			if (strcasecmp(host, "~") == 0) {
+				result = dns_sdlz_putnamedrr(
+					(dns_sdlzallnodes_t *)ptr, "*", type,
+					ttl, data);
+			} else {
+				result = dns_sdlz_putnamedrr(
+					(dns_sdlzallnodes_t *)ptr, host, type,
+					ttl, data);
+			}
+			if (result != ISC_R_SUCCESS) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "dlz-ldap: putnamedrr failed "
+					      "for \"%s %s %u %s\", %s",
+					      host, type, ttl, data,
+					      isc_result_totext(result));
+			}
+		} else {
+			result = dns_sdlz_putrr((dns_sdlzlookup_t *)ptr, type,
+						ttl, data);
+			if (result != ISC_R_SUCCESS) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "dlz-ldap: putrr failed "
+					      "for \"%s %u %s\", %s",
+					      type, ttl, data,
+					      isc_result_totext(result));
+			}
+		}
+
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver failed "
+				      "while sending data to BIND.");
+			goto cleanup;
+		}
+
+		/* free memory for type, data and host for next loop */
+		isc_mem_free(named_g_mctx, type);
+		isc_mem_free(named_g_mctx, data);
+		if (host != NULL) {
+			isc_mem_free(named_g_mctx, host);
+		}
+
+		/* get the next entry to process */
+		entry = ldap_next_entry(dbc, entry);
+	} /* end while (entry != NULL) */
+
+cleanup:
+	/* de-allocate memory */
+	if (vals != NULL) {
+		ldap_value_free(vals);
+	}
+	if (host != NULL) {
+		isc_mem_free(named_g_mctx, host);
+	}
+	if (type != NULL) {
+		isc_mem_free(named_g_mctx, type);
+	}
+	if (data != NULL) {
+		isc_mem_free(named_g_mctx, data);
+	}
+
+	return (result);
+}
+
+/*%
+ * This function is the real core of the driver.   Zone, record
+ * and client strings are passed in (or NULL is passed if the
+ * string is not available).  The type of query we want to run
+ * is indicated by the query flag, and the dbdata object is passed
+ * passed in to.  dbdata really holds either:
+ *		1) a list of database instances (in multithreaded mode) OR
+ *		2) a single database instance (in single threaded mode)
+ * The function will construct the query and obtain an available
+ * database instance (DBI).  It will then run the query and hopefully
+ * obtain a result set.
+ */
+static isc_result_t
+ldap_get_results(const char *zone, const char *record, const char *client,
+		 unsigned int query, void *dbdata, void *ptr) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	char *querystring = NULL;
+	LDAPURLDesc *ldap_url = NULL;
+	int ldap_result = 0;
+	LDAPMessage *ldap_msg = NULL;
+	int i;
+	int entries;
+
+	/* get db instance / connection */
+	/* find an available DBI from the list */
+	dbi = ldap_find_avail_conn(
+		(db_list_t *)((ldap_instance_t *)dbdata)->db);
+
+	/* if DBI is null, can't do anything else */
+	if (dbi == NULL) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* set fields */
+	if (zone != NULL) {
+		dbi->zone = isc_mem_strdup(named_g_mctx, zone);
+	} else {
+		dbi->zone = NULL;
+	}
+	if (record != NULL) {
+		dbi->record = isc_mem_strdup(named_g_mctx, record);
+	} else {
+		dbi->record = NULL;
+	}
+	if (client != NULL) {
+		dbi->client = isc_mem_strdup(named_g_mctx, client);
+	} else {
+		dbi->client = NULL;
+	}
+
+	/* what type of query are we going to run? */
+	switch (query) {
+	case ALLNODES:
+		/*
+		 * if the query was not passed in from the config file
+		 * then we can't run it.  return not_implemented, so
+		 * it's like the code for that operation was never
+		 * built into the driver.... AHHH flexibility!!!
+		 */
+		if (dbi->allnodes_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		} else {
+			querystring = build_querystring(named_g_mctx,
+							dbi->allnodes_q);
+		}
+		break;
+	case ALLOWXFR:
+		/* same as comments as ALLNODES */
+		if (dbi->allowxfr_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		} else {
+			querystring = build_querystring(named_g_mctx,
+							dbi->allowxfr_q);
+		}
+		break;
+	case AUTHORITY:
+		/* same as comments as ALLNODES */
+		if (dbi->authority_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		} else {
+			querystring = build_querystring(named_g_mctx,
+							dbi->authority_q);
+		}
+		break;
+	case FINDZONE:
+		/* this is required.  It's the whole point of DLZ! */
+		if (dbi->findzone_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for findzone.  "
+				      "Findzone requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		} else {
+			querystring = build_querystring(named_g_mctx,
+							dbi->findzone_q);
+		}
+		break;
+	case LOOKUP:
+		/* this is required.  It's also a major point of DLZ! */
+		if (dbi->lookup_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for lookup.  "
+				      "Lookup requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		} else {
+			querystring = build_querystring(named_g_mctx,
+							dbi->lookup_q);
+		}
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "ldap_get_results");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	/* if the querystring is null, Bummer, outta RAM.  UPGRADE TIME!!!   */
+	if (querystring == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	/*
+	 * output the full query string during debug so we can see
+	 * what lame error the query has.
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1), "\nQuery String: %s\n", querystring);
+
+	/* break URL down into it's component parts, if error cleanup */
+	ldap_result = ldap_url_parse(querystring, &ldap_url);
+	if (ldap_result != LDAP_SUCCESS || ldap_url == NULL) {
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	for (i = 0; i < 3; i++) {
+		/*
+		 * dbi->dbconn may be null if trying to reconnect on a
+		 * previous query failed.
+		 */
+		if (dbi->dbconn == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
+				      "LDAP driver attempting to re-connect");
+
+			result = dlz_ldap_connect((ldap_instance_t *)dbdata,
+						  dbi);
+			if (result != ISC_R_SUCCESS) {
+				result = ISC_R_FAILURE;
+				continue;
+			}
+		}
+
+		/* perform ldap search synchronously */
+		ldap_result =
+			ldap_search_s((LDAP *)dbi->dbconn, ldap_url->lud_dn,
+				      ldap_url->lud_scope, ldap_url->lud_filter,
+				      ldap_url->lud_attrs, 0, &ldap_msg);
+
+		/*
+		 * check return code.  No such object is ok, just
+		 * didn't find what we wanted
+		 */
+		switch (ldap_result) {
+		case LDAP_NO_SUCH_OBJECT:
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
+				      "No object found matching "
+				      "query requirements");
+			result = ISC_R_NOTFOUND;
+			goto cleanup;
+			break;
+		case LDAP_SUCCESS: /* on success do nothing */
+			result = ISC_R_SUCCESS;
+			i = 3;
+			break;
+		case LDAP_SERVER_DOWN:
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
+				      "LDAP driver attempting to re-connect");
+			result = dlz_ldap_connect((ldap_instance_t *)dbdata,
+						  dbi);
+			if (result != ISC_R_SUCCESS) {
+				result = ISC_R_FAILURE;
+			}
+			break;
+		default:
+			/*
+			 * other errors not ok.  Log error message and
+			 * get out
+			 */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP error: %s",
+				      ldap_err2string(ldap_result));
+			result = ISC_R_FAILURE;
+			goto cleanup;
+			break;
+		} /* close switch(ldap_result) */
+	}	  /* end for (int i = 0 i < 3; i++) */
+
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup;
+	}
+
+	switch (query) {
+	case ALLNODES:
+		result = ldap_process_results((LDAP *)dbi->dbconn, ldap_msg,
+					      ldap_url->lud_attrs, ptr, true);
+		break;
+	case AUTHORITY:
+	case LOOKUP:
+		result = ldap_process_results((LDAP *)dbi->dbconn, ldap_msg,
+					      ldap_url->lud_attrs, ptr, false);
+		break;
+	case ALLOWXFR:
+		entries = ldap_count_entries((LDAP *)dbi->dbconn, ldap_msg);
+		if (entries == 0) {
+			result = ISC_R_NOPERM;
+		} else if (entries > 0) {
+			result = ISC_R_SUCCESS;
+		} else {
+			result = ISC_R_FAILURE;
+		}
+		break;
+	case FINDZONE:
+		entries = ldap_count_entries((LDAP *)dbi->dbconn, ldap_msg);
+		if (entries == 0) {
+			result = ISC_R_NOTFOUND;
+		} else if (entries > 0) {
+			result = ISC_R_SUCCESS;
+		} else {
+			result = ISC_R_FAILURE;
+		}
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "ldap_get_results");
+		result = ISC_R_UNEXPECTED;
+	}
+
+cleanup:
+	/* it's always good to cleanup after yourself */
+
+	/* if we retrieved results, free them */
+	if (ldap_msg != NULL) {
+		ldap_msgfree(ldap_msg);
+	}
+
+	if (ldap_url != NULL) {
+		ldap_free_urldesc(ldap_url);
+	}
+
+	/* cleanup */
+	if (dbi->zone != NULL) {
+		isc_mem_free(named_g_mctx, dbi->zone);
+	}
+	if (dbi->record != NULL) {
+		isc_mem_free(named_g_mctx, dbi->record);
+	}
+	if (dbi->client != NULL) {
+		isc_mem_free(named_g_mctx, dbi->client);
+	}
+
+	/* release the lock so another thread can use this dbi */
+	isc_mutex_unlock(&dbi->instance_lock);
+
+	/* release query string */
+	if (querystring != NULL) {
+		isc_mem_free(named_g_mctx, querystring);
+	}
+
+	/* return result */
+	return (result);
+}
+
+/*
+ * DLZ methods
+ */
+static isc_result_t
+dlz_ldap_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		      const char *client) {
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	/* check to see if we are authoritative for the zone first */
+	result = dlz_ldap_findzone(driverarg, dbdata, name, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	/* get all the zone data */
+	result = ldap_get_results(name, NULL, client, ALLOWXFR, dbdata, NULL);
+	return (result);
+}
+
+static isc_result_t
+dlz_ldap_allnodes(const char *zone, void *driverarg, void *dbdata,
+		  dns_sdlzallnodes_t *allnodes) {
+	UNUSED(driverarg);
+	return (ldap_get_results(zone, NULL, NULL, ALLNODES, dbdata, allnodes));
+}
+
+static isc_result_t
+dlz_ldap_authority(const char *zone, void *driverarg, void *dbdata,
+		   dns_sdlzlookup_t *lookup) {
+	UNUSED(driverarg);
+	return (ldap_get_results(zone, NULL, NULL, AUTHORITY, dbdata, lookup));
+}
+
+static isc_result_t
+dlz_ldap_findzone(void *driverarg, void *dbdata, const char *name,
+		  dns_clientinfomethods_t *methods,
+		  dns_clientinfo_t *clientinfo) {
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+	return (ldap_get_results(name, NULL, NULL, FINDZONE, dbdata, NULL));
+}
+
+static isc_result_t
+dlz_ldap_lookup(const char *zone, const char *name, void *driverarg,
+		void *dbdata, dns_sdlzlookup_t *lookup,
+		dns_clientinfomethods_t *methods,
+		dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	if (strcmp(name, "*") == 0) {
+		result = ldap_get_results(zone, "~", NULL, LOOKUP, dbdata,
+					  lookup);
+	} else {
+		result = ldap_get_results(zone, name, NULL, LOOKUP, dbdata,
+					  lookup);
+	}
+	return (result);
+}
+
+static isc_result_t
+dlz_ldap_create(const char *dlzname, unsigned int argc, char *argv[],
+		void *driverarg, void **dbdata) {
+	isc_result_t result;
+	ldap_instance_t *ldap_inst = NULL;
+	dbinstance_t *dbi = NULL;
+	int protocol;
+	int method;
+	int dbcount;
+	char *endp;
+	/* db_list_t *dblist = NULL; */
+	int i;
+
+	UNUSED(dlzname);
+	UNUSED(driverarg);
+
+	/* if debugging, let user know we are multithreaded. */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1), "LDAP driver running multithreaded");
+
+	if (argc < 9) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "LDAP driver requires at least "
+			      "8 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* no more than 13 arg's should be passed to the driver */
+	if (argc > 12) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "LDAP driver cannot accept more than "
+			      "11 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* determine protocol version. */
+	if (strncasecmp(argv[2], V2, strlen(V2)) == 0) {
+		protocol = 2;
+	} else if (strncasecmp(argv[2], V3, strlen(V3)) == 0) {
+		protocol = 3;
+	} else {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "LDAP driver protocol must be either %s or %s",
+			      V2, V3);
+		return (ISC_R_FAILURE);
+	}
+
+	/* determine connection method. */
+	if (strncasecmp(argv[3], SIMPLE, strlen(SIMPLE)) == 0) {
+		method = LDAP_AUTH_SIMPLE;
+	} else if (strncasecmp(argv[3], KRB41, strlen(KRB41)) == 0) {
+		method = LDAP_AUTH_KRBV41;
+	} else if (strncasecmp(argv[3], KRB42, strlen(KRB42)) == 0) {
+		method = LDAP_AUTH_KRBV42;
+	} else {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "LDAP driver authentication method must be "
+			      "one of %s, %s or %s",
+			      SIMPLE, KRB41, KRB42);
+		return (ISC_R_FAILURE);
+	}
+
+	/* check how many db connections we should create */
+	dbcount = strtol(argv[1], &endp, 10);
+	if (*endp != '\0' || dbcount < 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "LDAP driver database connection count "
+			      "must be positive.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* check that LDAP URL parameters make sense */
+	switch (argc) {
+	case 12:
+		result = dlz_ldap_checkURL(argv[11], 0, "allow zone transfer");
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		FALLTHROUGH;
+	case 11:
+		result = dlz_ldap_checkURL(argv[10], 3, "all nodes");
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		FALLTHROUGH;
+	case 10:
+		if (strlen(argv[9]) > 0) {
+			result = dlz_ldap_checkURL(argv[9], 3, "authority");
+			if (result != ISC_R_SUCCESS) {
+				return (result);
+			}
+		}
+		FALLTHROUGH;
+	case 9:
+		result = dlz_ldap_checkURL(argv[8], 3, "lookup");
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		result = dlz_ldap_checkURL(argv[7], 0, "find zone");
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		break;
+	default:
+		/* not really needed, should shut up compiler. */
+		result = ISC_R_FAILURE;
+	}
+
+	/* allocate memory for LDAP instance */
+	ldap_inst = isc_mem_get(named_g_mctx, sizeof(ldap_instance_t));
+	memset(ldap_inst, 0, sizeof(ldap_instance_t));
+
+	/* store info needed to automatically re-connect. */
+	ldap_inst->protocol = protocol;
+	ldap_inst->method = method;
+	ldap_inst->hosts = isc_mem_strdup(named_g_mctx, argv[6]);
+	ldap_inst->user = isc_mem_strdup(named_g_mctx, argv[4]);
+	ldap_inst->cred = isc_mem_strdup(named_g_mctx, argv[5]);
+
+	/* allocate memory for database connection list */
+	ldap_inst->db = isc_mem_get(named_g_mctx, sizeof(db_list_t));
+
+	/* initialize DB connection list */
+	ISC_LIST_INIT(*(ldap_inst->db));
+
+	/*
+	 * create the appropriate number of database instances (DBI)
+	 * append each new DBI to the end of the list
+	 */
+	for (i = 0; i < dbcount; i++) {
+		/* how many queries were passed in from config file? */
+		switch (argc) {
+		case 9:
+			result = build_sqldbinstance(named_g_mctx, NULL, NULL,
+						     NULL, argv[7], argv[8],
+						     NULL, &dbi);
+			break;
+		case 10:
+			result = build_sqldbinstance(named_g_mctx, NULL, NULL,
+						     argv[9], argv[7], argv[8],
+						     NULL, &dbi);
+			break;
+		case 11:
+			result = build_sqldbinstance(named_g_mctx, argv[10],
+						     NULL, argv[9], argv[7],
+						     argv[8], NULL, &dbi);
+			break;
+		case 12:
+			result = build_sqldbinstance(named_g_mctx, argv[10],
+						     argv[11], argv[9], argv[7],
+						     argv[8], NULL, &dbi);
+			break;
+		default:
+			/* not really needed, should shut up compiler. */
+			result = ISC_R_FAILURE;
+		}
+
+		if (result == ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "LDAP driver created "
+				      "database instance object.");
+		} else { /* unsuccessful?, log err msg and cleanup. */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver could not create "
+				      "database instance object.");
+			goto cleanup;
+		}
+
+		ISC_LINK_INIT(dbi, link);
+		ISC_LIST_APPEND(*(ldap_inst->db), dbi, link);
+
+		/* attempt to connect */
+		result = dlz_ldap_connect(ldap_inst, dbi);
+
+		/*
+		 * if db connection cannot be created, log err msg and
+		 * cleanup.
+		 */
+		switch (result) {
+		/* success, do nothing */
+		case ISC_R_SUCCESS:
+			break;
+		/*
+		 * no memory means ldap_init could not
+		 * allocate memory
+		 */
+		case ISC_R_NOMEMORY:
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver could not allocate memory "
+				      "for connection number %u",
+				      i + 1);
+			goto cleanup;
+			break;
+		/*
+		 * no perm means ldap_set_option could not set
+		 * protocol version
+		 */
+		case ISC_R_NOPERM:
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver could not "
+				      "set protocol version.");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+			break;
+		/* failure means couldn't connect to ldap server */
+		case ISC_R_FAILURE:
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "LDAP driver could not "
+				      "bind connection number %u to server.",
+				      i + 1);
+			goto cleanup;
+			break;
+		/*
+		 * default should never happen.  If it does,
+		 * major errors.
+		 */
+		default:
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "dlz_ldap_create() failed: %s",
+					 isc_result_totext(result));
+			result = ISC_R_UNEXPECTED;
+			goto cleanup;
+			break;
+		} /* end switch(result) */
+
+		/* set DBI = null for next loop through. */
+		dbi = NULL;
+	} /* end for loop */
+
+	/* set dbdata to the ldap_instance we created. */
+	*dbdata = ldap_inst;
+
+	/* hey, we got through all of that ok, return success. */
+	return (ISC_R_SUCCESS);
+
+cleanup:
+	dlz_ldap_destroy(NULL, ldap_inst);
+
+	return (ISC_R_FAILURE);
+}
+
+void
+dlz_ldap_destroy(void *driverarg, void *dbdata) {
+	UNUSED(driverarg);
+
+	if (dbdata != NULL) {
+		/* cleanup the list of DBI's */
+		ldap_destroy_dblist(
+			(db_list_t *)((ldap_instance_t *)dbdata)->db);
+
+		if (((ldap_instance_t *)dbdata)->hosts != NULL) {
+			isc_mem_free(named_g_mctx,
+				     ((ldap_instance_t *)dbdata)->hosts);
+		}
+
+		if (((ldap_instance_t *)dbdata)->user != NULL) {
+			isc_mem_free(named_g_mctx,
+				     ((ldap_instance_t *)dbdata)->user);
+		}
+
+		if (((ldap_instance_t *)dbdata)->cred != NULL) {
+			isc_mem_free(named_g_mctx,
+				     ((ldap_instance_t *)dbdata)->cred);
+		}
+
+		isc_mem_put(named_g_mctx, dbdata, sizeof(ldap_instance_t));
+	}
+}
+
+static dns_sdlzmethods_t dlz_ldap_methods = {
+	dlz_ldap_create,
+	dlz_ldap_destroy,
+	dlz_ldap_findzone,
+	dlz_ldap_lookup,
+	dlz_ldap_authority,
+	dlz_ldap_allnodes,
+	dlz_ldap_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_ldap_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ ldap driver.");
+
+	result = dns_sdlzregister("ldap", &dlz_ldap_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA,
+				  named_g_mctx, &dlz_ldap);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_ldap_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ ldap driver.");
+
+	if (dlz_ldap != NULL) {
+		dns_sdlzunregister(&dlz_ldap);
+	}
+}
+
+#endif /* ifdef DLZ_LDAP */
diff --git a/contrib/dlz/drivers/dlz_mysql_driver.c b/contrib/dlz/drivers/dlz_mysql_driver.c
new file mode 100644
index 0000000..35c3fd9
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_mysql_driver.c
@@ -0,0 +1,1037 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_MYSQL
+#include <mysql.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_mysql_driver.h>
+#include <dlz/sdlz_helper.h>
+#include <named/globals.h>
+
+#if !defined(MARIADB_BASE_VERSION) && MYSQL_VERSION_ID >= 80000
+typedef bool my_bool;
+#endif /* !defined(MARIADB_BASE_VERSION) && MYSQL_VERSION_ID >= 80000 */
+
+static dns_sdlzimplementation_t *dlz_mysql = NULL;
+
+#define dbc_search_limit 30
+#define ALLNODES	 1
+#define ALLOWXFR	 2
+#define AUTHORITY	 3
+#define FINDZONE	 4
+#define COUNTZONE	 5
+#define LOOKUP		 6
+
+#define safeGet(in) in == NULL ? "" : in
+
+/*
+ * Private methods
+ */
+
+/*%
+ * Allocates memory for a new string, and then constructs the new
+ * string by "escaping" the input string.  The new string is
+ * safe to be used in queries.  This is necessary because we cannot
+ * be sure of what types of strings are passed to us, and we don't
+ * want special characters in the string causing problems.
+ */
+
+static char *
+mysqldrv_escape_string(MYSQL *mysql, const char *instr) {
+	char *outstr;
+	unsigned int len;
+
+	if (instr == NULL) {
+		return (NULL);
+	}
+
+	len = strlen(instr);
+
+	outstr = isc_mem_allocate(named_g_mctx, (2 * len * sizeof(char)) + 1);
+
+	mysql_real_escape_string(mysql, outstr, instr, len);
+
+	return (outstr);
+}
+
+/*%
+ * This function is the real core of the driver.   Zone, record
+ * and client strings are passed in (or NULL is passed if the
+ * string is not available).  The type of query we want to run
+ * is indicated by the query flag, and the dbdata object is passed
+ * passed in to.  dbdata really holds a single database instance.
+ * The function will construct and run the query, hopefully getting
+ * a result set.
+ */
+
+static isc_result_t
+mysql_get_resultset(const char *zone, const char *record, const char *client,
+		    unsigned int query, void *dbdata, MYSQL_RES **rs) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	char *querystring = NULL;
+	unsigned int i = 0;
+	unsigned int j = 0;
+	int qres = 0;
+
+	if (query != COUNTZONE) {
+		REQUIRE(*rs == NULL);
+	} else {
+		REQUIRE(rs == NULL);
+	}
+
+	/* get db instance / connection */
+	dbi = (dbinstance_t *)dbdata;
+
+	/* if DBI is null, can't do anything else */
+	if (dbi == NULL) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* what type of query are we going to run? */
+	switch (query) {
+	case ALLNODES:
+		/*
+		 * if the query was not passed in from the config file
+		 * then we can't run it.  return not_implemented, so
+		 * it's like the code for that operation was never
+		 * built into the driver.... AHHH flexibility!!!
+		 */
+		if (dbi->allnodes_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case ALLOWXFR:
+		/* same as comments as ALLNODES */
+		if (dbi->allowxfr_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case AUTHORITY:
+		/* same as comments as ALLNODES */
+		if (dbi->authority_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case FINDZONE:
+		/* this is required.  It's the whole point of DLZ! */
+		if (dbi->findzone_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for findzone.  "
+				      "Findzone requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	case COUNTZONE:
+		/* same as comments as ALLNODES */
+		if (dbi->countzone_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case LOOKUP:
+		/* this is required.  It's also a major point of DLZ! */
+		if (dbi->lookup_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for lookup.  "
+				      "Lookup requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "mysql_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	/*
+	 * was a zone string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (zone != NULL) {
+		dbi->zone = mysqldrv_escape_string((MYSQL *)dbi->dbconn, zone);
+		if (dbi->zone == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->zone = NULL;
+	}
+
+	/*
+	 * was a record string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (record != NULL) {
+		dbi->record = mysqldrv_escape_string((MYSQL *)dbi->dbconn,
+						     record);
+		if (dbi->record == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->record = NULL;
+	}
+
+	/*
+	 * was a client string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (client != NULL) {
+		dbi->client = mysqldrv_escape_string((MYSQL *)dbi->dbconn,
+						     client);
+		if (dbi->client == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->client = NULL;
+	}
+
+	/*
+	 * what type of query are we going to run?  this time we build
+	 * the actual query to run.
+	 */
+	switch (query) {
+	case ALLNODES:
+		querystring = build_querystring(named_g_mctx, dbi->allnodes_q);
+		break;
+	case ALLOWXFR:
+		querystring = build_querystring(named_g_mctx, dbi->allowxfr_q);
+		break;
+	case AUTHORITY:
+		querystring = build_querystring(named_g_mctx, dbi->authority_q);
+		break;
+	case FINDZONE:
+		querystring = build_querystring(named_g_mctx, dbi->findzone_q);
+		break;
+	case COUNTZONE:
+		querystring = build_querystring(named_g_mctx, dbi->countzone_q);
+		break;
+	case LOOKUP:
+		querystring = build_querystring(named_g_mctx, dbi->lookup_q);
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "mysql_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	/* if the querystring is null, Bummer, outta RAM.  UPGRADE TIME!!!   */
+	if (querystring == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	/*
+	 * output the full query string during debug so we can see
+	 * what lame error the query has.
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1), "\nQuery String: %s\n", querystring);
+
+	/* attempt query up to 3 times. */
+	for (i = 0; i < 3; i++) {
+		qres = mysql_query((MYSQL *)dbi->dbconn, querystring);
+		if (qres == 0) {
+			break;
+		}
+		for (j = 0; mysql_ping((MYSQL *)dbi->dbconn) != 0 && j < 4; j++)
+		{
+			;
+		}
+	}
+
+	if (qres == 0) {
+		result = ISC_R_SUCCESS;
+		if (query != COUNTZONE) {
+			*rs = mysql_store_result((MYSQL *)dbi->dbconn);
+			if (*rs == NULL) {
+				result = ISC_R_FAILURE;
+			}
+		}
+	} else {
+		result = ISC_R_FAILURE;
+	}
+
+cleanup:
+	/* it's always good to cleanup after yourself */
+
+	/* free dbi->zone string */
+	if (dbi->zone != NULL) {
+		isc_mem_free(named_g_mctx, dbi->zone);
+	}
+
+	/* free dbi->record string */
+	if (dbi->record != NULL) {
+		isc_mem_free(named_g_mctx, dbi->record);
+	}
+
+	/* free dbi->client string */
+	if (dbi->client != NULL) {
+		isc_mem_free(named_g_mctx, dbi->client);
+	}
+
+	/* release query string */
+	if (querystring != NULL) {
+		isc_mem_free(named_g_mctx, querystring);
+	}
+
+	/* return result */
+	return (result);
+}
+
+/*%
+ * The processing of result sets for lookup and authority are
+ * exactly the same.  So that functionality has been moved
+ * into this function to minimize code.
+ */
+
+static isc_result_t
+mysql_process_rs(dns_sdlzlookup_t *lookup, MYSQL_RES *rs) {
+	isc_result_t result = ISC_R_NOTFOUND;
+	MYSQL_ROW row;
+	unsigned int fields;
+	unsigned int j;
+	unsigned int len;
+	char *tmpString;
+	char *endp;
+	int ttl;
+
+	row = mysql_fetch_row(rs);     /* get a row from the result set */
+	fields = mysql_num_fields(rs); /* how many columns in result set */
+	while (row != NULL) {
+		switch (fields) {
+		case 1:
+			/*
+			 * one column in rs, it's the data field.  use
+			 * default type of A record, and default TTL
+			 * of 86400
+			 */
+			result = dns_sdlz_putrr(lookup, "a", 86400,
+						safeGet(row[0]));
+			break;
+		case 2:
+			/*
+			 * two columns, data field, and data type.
+			 * use default TTL of 86400.
+			 */
+			result = dns_sdlz_putrr(lookup, safeGet(row[0]), 86400,
+						safeGet(row[1]));
+			break;
+		case 3:
+			/*
+			 * three columns, all data no defaults.
+			 * convert text to int, make sure it worked
+			 * right.
+			 */
+			ttl = strtol(safeGet(row[0]), &endp, 10);
+			if (*endp != '\0' || ttl < 0) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "mysql driver ttl must be "
+					      "a positive number");
+			}
+			result = dns_sdlz_putrr(lookup, safeGet(row[1]), ttl,
+						safeGet(row[2]));
+			break;
+		default:
+			/*
+			 * more than 3 fields, concatenate the last
+			 * ones together.  figure out how long to make
+			 * string.
+			 */
+			for (j = 2, len = 0; j < fields; j++) {
+				len += strlen(safeGet(row[j])) + 1;
+			}
+			/*
+			 * allocate string memory, allow for NULL to
+			 * term string
+			 */
+			tmpString = isc_mem_allocate(named_g_mctx, len + 1);
+			/* copy field to tmpString */
+			strcpy(tmpString, safeGet(row[2]));
+
+			/*
+			 * concat the rest of fields together, space
+			 * between each one.
+			 */
+			for (j = 3; j < fields; j++) {
+				strcat(tmpString, " ");
+				strcat(tmpString, safeGet(row[j]));
+			}
+			/* convert text to int, make sure it worked right */
+			ttl = strtol(safeGet(row[0]), &endp, 10);
+			if (*endp != '\0' || ttl < 0) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "mysql driver ttl must be "
+					      "a positive number");
+			}
+			/* ok, now tell Bind about it. */
+			result = dns_sdlz_putrr(lookup, safeGet(row[1]), ttl,
+						tmpString);
+			/* done, get rid of this thing. */
+			isc_mem_free(named_g_mctx, tmpString);
+		}
+		/* I sure hope we were successful */
+		if (result != ISC_R_SUCCESS) {
+			/* nope, get rid of the Result set, and log a msg */
+			mysql_free_result(rs);
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "dns_sdlz_putrr returned error. "
+				      "Error code was: %s",
+				      isc_result_totext(result));
+			return (ISC_R_FAILURE);
+		}
+		row = mysql_fetch_row(rs); /* get next row */
+	}
+
+	/* free result set memory */
+	mysql_free_result(rs);
+
+	/* return result code */
+	return (result);
+}
+
+/*
+ * SDLZ interface methods
+ */
+
+/*% determine if the zone is supported by (in) the database */
+
+static isc_result_t
+mysql_findzone(void *driverarg, void *dbdata, const char *name,
+	       dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+	my_ulonglong rows;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	/* run the query and get the result set from the database. */
+	result = mysql_get_resultset(name, NULL, NULL, FINDZONE, dbdata, &rs);
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS || rs == NULL) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver unable to return "
+			      "result set for findzone query");
+		return (ISC_R_FAILURE);
+	}
+	/* count how many rows in result set */
+	rows = mysql_num_rows(rs);
+	/* get rid of result set, we are done with it. */
+	mysql_free_result(rs);
+
+	/* if we returned any rows, zone is supported. */
+	if (rows > 0) {
+		mysql_get_resultset(name, NULL, NULL, COUNTZONE, dbdata, NULL);
+		return (ISC_R_SUCCESS);
+	}
+
+	/* no rows returned, zone is not supported. */
+	return (ISC_R_NOTFOUND);
+}
+
+/*% Determine if the client is allowed to perform a zone transfer */
+static isc_result_t
+mysql_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		   const char *client) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+	my_ulonglong rows;
+
+	UNUSED(driverarg);
+
+	/* first check if the zone is supported by the database. */
+	result = mysql_findzone(driverarg, dbdata, name, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	/*
+	 * if we get to this point we know the zone is supported by
+	 * the database the only questions now are is the zone
+	 * transfer is allowed for this client and did the config file
+	 * have an allow zone xfr query.
+	 *
+	 * Run our query, and get a result set from the database.
+	 */
+	result = mysql_get_resultset(name, NULL, client, ALLOWXFR, dbdata, &rs);
+	/* if we get "not implemented", send it along. */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS || rs == NULL) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver unable to return "
+			      "result set for allow xfr query");
+		return (ISC_R_FAILURE);
+	}
+	/* count how many rows in result set */
+	rows = mysql_num_rows(rs);
+	/* get rid of result set, we are done with it. */
+	mysql_free_result(rs);
+
+	/* if we returned any rows, zone xfr is allowed. */
+	if (rows > 0) {
+		return (ISC_R_SUCCESS);
+	}
+
+	/* no rows returned, zone xfr not allowed */
+	return (ISC_R_NOPERM);
+}
+
+/*%
+ * If the client is allowed to perform a zone transfer, the next order of
+ * business is to get all the nodes in the zone, so bind can respond to the
+ * query.
+ */
+static isc_result_t
+mysql_allnodes(const char *zone, void *driverarg, void *dbdata,
+	       dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+	MYSQL_ROW row;
+	unsigned int fields;
+	unsigned int j;
+	unsigned int len;
+	char *tmpString;
+	char *endp;
+	int ttl;
+
+	UNUSED(driverarg);
+
+	/* run the query and get the result set from the database. */
+	result = mysql_get_resultset(zone, NULL, NULL, ALLNODES, dbdata, &rs);
+	/* if we get "not implemented", send it along */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver unable to return "
+			      "result set for all nodes query");
+		return (ISC_R_FAILURE);
+	}
+
+	result = ISC_R_NOTFOUND;
+
+	row = mysql_fetch_row(rs);     /* get a row from the result set */
+	fields = mysql_num_fields(rs); /* how many columns in result set */
+	while (row != NULL) {
+		if (fields < 4) { /* gotta have at least 4 columns */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "mysql driver too few fields returned "
+				      "by all nodes query");
+		}
+		/* convert text to int, make sure it worked right  */
+		ttl = strtol(safeGet(row[0]), &endp, 10);
+		if (*endp != '\0' || ttl < 0) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "mysql driver ttl must be "
+				      "a positive number");
+		}
+		if (fields == 4) {
+			/* tell Bind about it. */
+			result = dns_sdlz_putnamedrr(allnodes, safeGet(row[2]),
+						     safeGet(row[1]), ttl,
+						     safeGet(row[3]));
+		} else {
+			/*
+			 * more than 4 fields, concatenate the last
+			 * ones together.  figure out how long to make
+			 * string.
+			 */
+			for (j = 3, len = 0; j < fields; j++) {
+				len += strlen(safeGet(row[j])) + 1;
+			}
+			/* allocate memory, allow for NULL to term string */
+			tmpString = isc_mem_allocate(named_g_mctx, len + 1);
+			/* copy this field to tmpString */
+			strcpy(tmpString, safeGet(row[3]));
+			/* concatenate the rest, with spaces between */
+			for (j = 4; j < fields; j++) {
+				strcat(tmpString, " ");
+				strcat(tmpString, safeGet(row[j]));
+			}
+			/* tell Bind about it. */
+			result = dns_sdlz_putnamedrr(allnodes, safeGet(row[2]),
+						     safeGet(row[1]), ttl,
+						     tmpString);
+			isc_mem_free(named_g_mctx, tmpString);
+		}
+		/* if we weren't successful, log err msg */
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "dns_sdlz_putnamedrr returned error. "
+				      "Error code was: %s",
+				      isc_result_totext(result));
+			result = ISC_R_FAILURE;
+			break;
+		}
+		/* get next row from the result set */
+		row = mysql_fetch_row(rs);
+	}
+
+	/* free result set memory */
+	mysql_free_result(rs);
+
+	return (result);
+}
+
+/*% if the lookup function does not return SOA or NS records for the zone,
+ * use this function to get that information for Bind.
+ */
+
+static isc_result_t
+mysql_authority(const char *zone, void *driverarg, void *dbdata,
+		dns_sdlzlookup_t *lookup) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+
+	UNUSED(driverarg);
+
+	/* run the query and get the result set from the database. */
+	result = mysql_get_resultset(zone, NULL, NULL, AUTHORITY, dbdata, &rs);
+	/* if we get "not implemented", send it along */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver unable to return "
+			      "result set for authority query");
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * lookup and authority result sets are processed in the same
+	 * manner mysql_process_rs does the job for both functions.
+	 */
+	return (mysql_process_rs(lookup, rs));
+}
+
+/*% if zone is supported, lookup up a (or multiple) record(s) in it */
+static isc_result_t
+mysql_lookup(const char *zone, const char *name, void *driverarg, void *dbdata,
+	     dns_sdlzlookup_t *lookup, dns_clientinfomethods_t *methods,
+	     dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	/* run the query and get the result set from the database. */
+	result = mysql_get_resultset(zone, name, NULL, LOOKUP, dbdata, &rs);
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver unable to return "
+			      "result set for lookup query");
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * lookup and authority result sets are processed in the same manner
+	 * mysql_process_rs does the job for both functions.
+	 */
+	return (mysql_process_rs(lookup, rs));
+}
+
+/*%
+ * create an instance of the driver.  Remember, only 1 copy of the driver's
+ * code is ever loaded, the driver has to remember which context it's
+ * operating in.  This is done via use of the dbdata argument which is
+ * passed into all query functions.
+ */
+static isc_result_t
+mysql_create(const char *dlzname, unsigned int argc, char *argv[],
+	     void *driverarg, void **dbdata) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	char *tmp = NULL;
+	char *dbname = NULL;
+	char *host = NULL;
+	char *user = NULL;
+	char *pass = NULL;
+	char *socket = NULL;
+	int port;
+	MYSQL *dbc;
+	char *endp;
+	int j;
+	unsigned int flags = 0;
+
+	UNUSED(driverarg);
+	UNUSED(dlzname);
+
+	/* verify we have at least 4 arg's passed to the driver */
+	if (argc < 4) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver requires "
+			      "at least 4 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* no more than 8 arg's should be passed to the driver */
+	if (argc > 8) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver cannot accept "
+			      "more than 7 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* parse connection string and get parameters. */
+
+	/* get db name - required */
+	dbname = getParameterValue(argv[1], "dbname=");
+	if (dbname == NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver requires a dbname parameter.");
+		result = ISC_R_FAILURE;
+		goto full_cleanup;
+	}
+
+	/* get db port.  Not required, but must be > 0 if specified */
+	tmp = getParameterValue(argv[1], "port=");
+	if (tmp == NULL) {
+		port = 0;
+	} else {
+		port = strtol(tmp, &endp, 10);
+		if (*endp != '\0' || port < 0) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Mysql driver port "
+				      "must be a positive number.");
+			isc_mem_free(named_g_mctx, tmp);
+			result = ISC_R_FAILURE;
+			goto full_cleanup;
+		}
+		isc_mem_free(named_g_mctx, tmp);
+	}
+
+	/* how many queries were passed in from config file? */
+	switch (argc) {
+	case 4:
+		result = build_sqldbinstance(named_g_mctx, NULL, NULL, NULL,
+					     argv[2], argv[3], NULL, &dbi);
+		break;
+	case 5:
+		result = build_sqldbinstance(named_g_mctx, NULL, NULL, argv[4],
+					     argv[2], argv[3], NULL, &dbi);
+		break;
+	case 6:
+		result = build_sqldbinstance(named_g_mctx, argv[5], NULL,
+					     argv[4], argv[2], argv[3], NULL,
+					     &dbi);
+		break;
+	case 7:
+		result = build_sqldbinstance(named_g_mctx, argv[5], argv[6],
+					     argv[4], argv[2], argv[3], NULL,
+					     &dbi);
+		break;
+	case 8:
+		result = build_sqldbinstance(named_g_mctx, argv[5], argv[6],
+					     argv[4], argv[2], argv[3], argv[7],
+					     &dbi);
+		break;
+	default:
+		/* not really needed, should shut up compiler. */
+		result = ISC_R_FAILURE;
+	}
+
+	/* unsuccessful?, log err msg and cleanup. */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver could not create "
+			      "database instance object.");
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	/* create and set db connection */
+	dbi->dbconn = mysql_init(NULL);
+
+	/* if db connection cannot be created, log err msg and cleanup. */
+	if (dbi->dbconn == NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver could not allocate "
+			      "memory for database connection");
+		result = ISC_R_FAILURE;
+		goto full_cleanup;
+	}
+
+	tmp = getParameterValue(argv[1], "compress=");
+	if (tmp != NULL) {
+		if (strcasecmp(tmp, "true") == 0) {
+			flags = CLIENT_COMPRESS;
+		}
+		isc_mem_free(named_g_mctx, tmp);
+	}
+
+	tmp = getParameterValue(argv[1], "ssl=");
+	if (tmp != NULL) {
+		if (strcasecmp(tmp, "true") == 0) {
+			flags = flags | CLIENT_SSL;
+		}
+		isc_mem_free(named_g_mctx, tmp);
+	}
+
+	tmp = getParameterValue(argv[1], "space=");
+	if (tmp != NULL) {
+		if (strcasecmp(tmp, "ignore") == 0) {
+			flags = flags | CLIENT_IGNORE_SPACE;
+		}
+		isc_mem_free(named_g_mctx, tmp);
+	}
+
+	dbc = NULL;
+	host = getParameterValue(argv[1], "host=");
+	user = getParameterValue(argv[1], "user=");
+	pass = getParameterValue(argv[1], "pass=");
+	socket = getParameterValue(argv[1], "socket=");
+
+	/* enable automatic reconnection. */
+	if (mysql_options((MYSQL *)dbi->dbconn, MYSQL_OPT_RECONNECT,
+			  &(my_bool){ 1 }) != 0)
+	{
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_WARNING,
+			      "mysql driver failed to set "
+			      "MYSQL_OPT_RECONNECT option, "
+			      "continuing");
+	}
+
+	for (j = 0; dbc == NULL && j < 4; j++) {
+		dbc = mysql_real_connect((MYSQL *)dbi->dbconn, host, user, pass,
+					 dbname, port, socket, flags);
+	}
+
+	/* let user know if we couldn't connect. */
+	if (dbc == NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "mysql driver failed to create "
+			      "database connection after 4 attempts");
+		result = ISC_R_FAILURE;
+		goto full_cleanup;
+	}
+
+	/* return db connection via dbdata */
+	*dbdata = dbi;
+
+	result = ISC_R_SUCCESS;
+	goto cleanup;
+
+full_cleanup:
+
+	if (dbi != NULL) {
+		destroy_sqldbinstance(dbi);
+	}
+
+cleanup:
+
+	if (dbname != NULL) {
+		isc_mem_free(named_g_mctx, dbname);
+	}
+	if (host != NULL) {
+		isc_mem_free(named_g_mctx, host);
+	}
+	if (user != NULL) {
+		isc_mem_free(named_g_mctx, user);
+	}
+	if (pass != NULL) {
+		isc_mem_free(named_g_mctx, pass);
+	}
+	if (socket != NULL) {
+		isc_mem_free(named_g_mctx, socket);
+	}
+
+	return (result);
+}
+
+/*%
+ * destroy the driver.  Remember, only 1 copy of the driver's
+ * code is ever loaded, the driver has to remember which context it's
+ * operating in.  This is done via use of the dbdata argument.
+ * so we really only need to clean it up since we are not using driverarg.
+ */
+
+static void
+mysql_destroy(void *driverarg, void *dbdata) {
+	dbinstance_t *dbi;
+
+	UNUSED(driverarg);
+
+	dbi = (dbinstance_t *)dbdata;
+
+	/* release DB connection */
+	if (dbi->dbconn != NULL) {
+		mysql_close((MYSQL *)dbi->dbconn);
+	}
+
+	/* destroy DB instance */
+	destroy_sqldbinstance(dbi);
+}
+
+/* pointers to all our runtime methods. */
+/* this is used during driver registration */
+/* i.e. in dlz_mysql_init below. */
+static dns_sdlzmethods_t dlz_mysql_methods = {
+	mysql_create,
+	mysql_destroy,
+	mysql_findzone,
+	mysql_lookup,
+	mysql_authority,
+	mysql_allnodes,
+	mysql_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_mysql_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ mysql driver.");
+
+	/* Driver is always threadsafe.  Because of the way MySQL handles
+	 * threads the MySQL driver can only be used when bind is run single
+	 * threaded.  Using MySQL with Bind running multi-threaded is not
+	 * allowed.  When using the MySQL driver "-n1" should always be
+	 * passed to Bind to guarantee single threaded operation.
+	 */
+	result = dns_sdlzregister("mysql", &dlz_mysql_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA |
+					  DNS_SDLZFLAG_THREADSAFE,
+				  named_g_mctx, &dlz_mysql);
+	/* if we can't register the driver, there are big problems. */
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_mysql_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ mysql driver.");
+
+	/* unregister the driver. */
+	if (dlz_mysql != NULL) {
+		dns_sdlzunregister(&dlz_mysql);
+	}
+}
+
+#endif /* ifdef DLZ_MYSQL */
diff --git a/contrib/dlz/drivers/dlz_odbc_driver.c b/contrib/dlz/drivers/dlz_odbc_driver.c
new file mode 100644
index 0000000..dae5510
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_odbc_driver.c
@@ -0,0 +1,1406 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_ODBC
+#include <sql.h>
+#include <sqlext.h>
+#include <sqltypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_odbc_driver.h>
+#include <dlz/sdlz_helper.h>
+#include <named/globals.h>
+
+static dns_sdlzimplementation_t *dlz_odbc = NULL;
+
+#define dbc_search_limit 30
+#define ALLNODES	 1
+#define ALLOWXFR	 2
+#define AUTHORITY	 3
+#define FINDZONE	 4
+#define LOOKUP		 5
+
+#define sqlOK(a) ((a == SQL_SUCCESS || a == SQL_SUCCESS_WITH_INFO) ? -1 : 0)
+
+/*
+ * Private Structures
+ */
+
+/*
+ * structure to hold ODBC connection & statement
+ */
+
+typedef struct {
+	SQLHDBC dbc;
+	SQLHSTMT stmnt;
+} odbc_db_t;
+
+/*
+ * Structure to hold everything needed by this "instance" of the odbc driver
+ * remember, the driver code is only loaded once, but may have many separate
+ * instances
+ */
+
+typedef struct {
+	db_list_t *db;	 /* handle to a list of DB */
+	SQLHENV sql_env; /* handle to SQL environment */
+	SQLCHAR *dsn;
+	SQLCHAR *user;
+	SQLCHAR *pass;
+} odbc_instance_t;
+
+/* forward reference */
+
+static size_t
+odbc_makesafe(char *to, const char *from, size_t length);
+
+/*
+ * Private methods
+ */
+
+static SQLSMALLINT
+safeLen(void *a) {
+	if (a == NULL) {
+		return (0);
+	}
+	return (strlen((char *)a));
+}
+
+/*% properly cleans up an odbc_instance_t */
+
+static void
+destroy_odbc_instance(odbc_instance_t *odbc_inst) {
+	dbinstance_t *ndbi = NULL;
+	dbinstance_t *dbi = NULL;
+
+	/* get the first DBI in the list */
+	ndbi = ISC_LIST_HEAD(*odbc_inst->db);
+
+	/* loop through the list */
+	while (ndbi != NULL) {
+		dbi = ndbi;
+		/* get the next DBI in the list */
+		ndbi = ISC_LIST_NEXT(dbi, link);
+
+		/* if we have a connection / statement object in memory */
+		if (dbi->dbconn != NULL) {
+			/* free statement handle */
+			if (((odbc_db_t *)(dbi->dbconn))->stmnt != NULL) {
+				SQLFreeHandle(
+					SQL_HANDLE_STMT,
+					((odbc_db_t *)(dbi->dbconn))->stmnt);
+				((odbc_db_t *)(dbi->dbconn))->stmnt = NULL;
+			}
+
+			/* disconnect from database & free connection handle */
+			if (((odbc_db_t *)(dbi->dbconn))->dbc != NULL) {
+				SQLDisconnect(((odbc_db_t *)dbi->dbconn)->dbc);
+				SQLFreeHandle(
+					SQL_HANDLE_DBC,
+					((odbc_db_t *)(dbi->dbconn))->dbc);
+				((odbc_db_t *)(dbi->dbconn))->dbc = NULL;
+			}
+
+			/* free memory that held connection & statement. */
+			isc_mem_free(named_g_mctx, dbi->dbconn);
+		}
+		/* release all memory that comprised a DBI */
+		destroy_sqldbinstance(dbi);
+	}
+	/* release memory for the list structure */
+	isc_mem_put(named_g_mctx, odbc_inst->db, sizeof(db_list_t));
+
+	/* free sql environment */
+	if (odbc_inst->sql_env != NULL) {
+		SQLFreeHandle(SQL_HANDLE_ENV, odbc_inst->sql_env);
+	}
+
+	/* free ODBC instance strings */
+	if (odbc_inst->dsn != NULL) {
+		isc_mem_free(named_g_mctx, odbc_inst->dsn);
+	}
+	if (odbc_inst->pass != NULL) {
+		isc_mem_free(named_g_mctx, odbc_inst->pass);
+	}
+	if (odbc_inst->user != NULL) {
+		isc_mem_free(named_g_mctx, odbc_inst->user);
+	}
+
+	/* free memory for odbc_inst */
+	if (odbc_inst != NULL) {
+		isc_mem_put(named_g_mctx, odbc_inst, sizeof(odbc_instance_t));
+	}
+}
+
+/*% Connects to database, and creates ODBC statements */
+
+static isc_result_t
+odbc_connect(odbc_instance_t *dbi, odbc_db_t **dbc) {
+	odbc_db_t *ndb = *dbc;
+	SQLRETURN sqlRes;
+	isc_result_t result = ISC_R_SUCCESS;
+
+	if (ndb != NULL) {
+		/*
+		 * if db != null, we have to do some cleanup
+		 * if statement handle != null free it
+		 */
+		if (ndb->stmnt != NULL) {
+			SQLFreeHandle(SQL_HANDLE_STMT, ndb->stmnt);
+			ndb->stmnt = NULL;
+		}
+
+		/* if connection handle != null free it */
+		if (ndb->dbc != NULL) {
+			SQLFreeHandle(SQL_HANDLE_DBC, ndb->dbc);
+			ndb->dbc = NULL;
+		}
+	} else {
+		ndb = isc_mem_allocate(named_g_mctx, sizeof(odbc_db_t));
+		memset(ndb, 0, sizeof(odbc_db_t));
+	}
+
+	sqlRes = SQLAllocHandle(SQL_HANDLE_DBC, dbi->sql_env, &(ndb->dbc));
+	if (!sqlOK(sqlRes)) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to allocate memory");
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	sqlRes = SQLConnect(ndb->dbc, dbi->dsn, safeLen(dbi->dsn), dbi->user,
+			    safeLen(dbi->user), dbi->pass, safeLen(dbi->pass));
+	if (!sqlOK(sqlRes)) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to connect");
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	sqlRes = SQLAllocHandle(SQL_HANDLE_STMT, ndb->dbc, &(ndb->stmnt));
+	if (!sqlOK(sqlRes)) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to allocate memory");
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	*dbc = ndb;
+
+	return (ISC_R_SUCCESS);
+
+cleanup:
+
+	if (ndb != NULL) {
+		/* if statement handle != null free it */
+		if (ndb->stmnt != NULL) {
+			SQLFreeHandle(SQL_HANDLE_STMT, ndb->stmnt);
+			ndb->stmnt = NULL;
+		}
+
+		/* if connection handle != null free it */
+		if (ndb->dbc != NULL) {
+			SQLDisconnect(ndb->dbc);
+			SQLFreeHandle(SQL_HANDLE_DBC, ndb->dbc);
+			ndb->dbc = NULL;
+		}
+		/* free memory holding ndb */
+		isc_mem_free(named_g_mctx, ndb);
+	}
+
+	return (result);
+}
+
+/*%
+ * Loops through the list of DB instances, attempting to lock
+ * on the mutex.  If successful, the DBI is reserved for use
+ * and the thread can perform queries against the database.
+ * If the lock fails, the next one in the list is tried.
+ * looping continues until a lock is obtained, or until
+ * the list has been searched dbc_search_limit times.
+ * This function is only used when the driver is compiled for
+ * multithreaded operation.
+ */
+
+static dbinstance_t *
+odbc_find_avail_conn(db_list_t *dblist) {
+	dbinstance_t *dbi = NULL;
+	dbinstance_t *head;
+	int count = 0;
+
+	/* get top of list */
+	head = dbi = ISC_LIST_HEAD(*dblist);
+
+	/* loop through list */
+	while (count < dbc_search_limit) {
+		/* try to lock on the mutex */
+		if (isc_mutex_trylock(&dbi->instance_lock) == ISC_R_SUCCESS) {
+			return (dbi); /* success, return the DBI for use. */
+		}
+		/* not successful, keep trying */
+		dbi = ISC_LIST_NEXT(dbi, link);
+
+		/* check to see if we have gone to the top of the list. */
+		if (dbi == NULL) {
+			count++;
+			dbi = head;
+		}
+	}
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_INFO,
+		      "Odbc driver unable to find available "
+		      "connection after searching %d times",
+		      count);
+	return (NULL);
+}
+
+/*% Allocates memory for a new string, and then constructs the new
+ * string by "escaping" the input string.  The new string is
+ * safe to be used in queries.  This is necessary because we cannot
+ * be sure of what types of strings are passed to us, and we don't
+ * want special characters in the string causing problems.
+ */
+
+static char *
+odbc_escape_string(const char *instr) {
+	char *outstr;
+	unsigned int len;
+
+	if (instr == NULL) {
+		return (NULL);
+	}
+
+	len = strlen(instr);
+
+	outstr = isc_mem_allocate(named_g_mctx, (2 * len * sizeof(char)) + 1);
+
+	odbc_makesafe(outstr, instr, len);
+
+	return (outstr);
+}
+
+/* ---------------
+ * Escaping arbitrary strings to get valid SQL strings/identifiers.
+ *
+ * Replaces "\\" with "\\\\" and "'" with "''".
+ * length is the length of the buffer pointed to by
+ * from.  The buffer at to must be at least 2*length + 1 characters
+ * long.  A terminating NUL character is written.
+ *
+ * NOTICE!!!
+ * This function was borrowed directly from PostgreSQL's libpq.
+ *
+ * The copyright statements from the original file containing this
+ * function are included below:
+ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ * ---------------
+ */
+
+static size_t
+odbc_makesafe(char *to, const char *from, size_t length) {
+	const char *source = from;
+	char *target = to;
+	unsigned int remaining = length;
+
+	while (remaining > 0) {
+		switch (*source) {
+		case '\\':
+			*target = '\\';
+			target++;
+			*target = '\\';
+			/* target and remaining are updated below. */
+			break;
+
+		case '\'':
+			*target = '\'';
+			target++;
+			*target = '\'';
+			/* target and remaining are updated below. */
+			break;
+
+		default:
+			*target = *source;
+			/* target and remaining are updated below. */
+		}
+		source++;
+		target++;
+		remaining--;
+	}
+
+	/* Write the terminating NUL character. */
+	*target = '\0';
+
+	return (target - to);
+}
+
+/*%
+ * This function is the real core of the driver.   Zone, record
+ * and client strings are passed in (or NULL is passed if the
+ * string is not available).  The type of query we want to run
+ * is indicated by the query flag, and the dbdata object is passed
+ * passed in to.  dbdata really holds either:
+ *		1) a list of database instances (in multithreaded mode) OR
+ *		2) a single database instance (in single threaded mode)
+ * The function will construct the query and obtain an available
+ * database instance (DBI).  It will then run the query and hopefully
+ * obtain a result set.  The data base instance that is used is returned
+ * to the caller so they can get the data from the result set from it.
+ * If successful, it will be the responsibility of the caller to close
+ * the cursor, and unlock the mutex of the DBI when they are done with it.
+ * If not successful, this function will perform all the cleanup.
+ */
+
+static isc_result_t
+odbc_get_resultset(const char *zone, const char *record, const char *client,
+		   unsigned int query, void *dbdata, dbinstance_t **r_dbi) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	char *querystring = NULL;
+	unsigned int j = 0;
+	SQLRETURN sqlRes;
+
+	REQUIRE(*r_dbi == NULL);
+
+	/* get db instance / connection */
+
+	/* find an available DBI from the list */
+	dbi = odbc_find_avail_conn(((odbc_instance_t *)dbdata)->db);
+
+	/* if DBI is null, can't do anything else */
+	if (dbi == NULL) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* what type of query are we going to run? */
+	switch (query) {
+	case ALLNODES:
+		/*
+		 * if the query was not passed in from the config file
+		 * then we can't run it.  return not_implemented, so
+		 * it's like the code for that operation was never
+		 * built into the driver.... AHHH flexibility!!!
+		 */
+		if (dbi->allnodes_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case ALLOWXFR:
+		/* same as comments as ALLNODES */
+		if (dbi->allowxfr_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case AUTHORITY:
+		/* same as comments as ALLNODES */
+		if (dbi->authority_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case FINDZONE:
+		/* this is required.  It's the whole point of DLZ! */
+		if (dbi->findzone_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for findzone.  "
+				      "Findzone requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	case LOOKUP:
+		/* this is required.  It's also a major point of DLZ! */
+		if (dbi->lookup_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for lookup.  "
+				      "Lookup requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "odbc_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	/*
+	 * was a zone string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (zone != NULL) {
+		dbi->zone = odbc_escape_string(zone);
+		if (dbi->zone == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->zone = NULL;
+	}
+
+	/*
+	 * was a record string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (record != NULL) {
+		dbi->record = odbc_escape_string(record);
+		if (dbi->record == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->record = NULL;
+	}
+
+	/*
+	 * was a client string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (client != NULL) {
+		dbi->client = odbc_escape_string(client);
+		if (dbi->client == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->client = NULL;
+	}
+
+	/*
+	 * what type of query are we going to run?
+	 * this time we build the actual query to run.
+	 */
+	switch (query) {
+	case ALLNODES:
+		querystring = build_querystring(named_g_mctx, dbi->allnodes_q);
+		break;
+	case ALLOWXFR:
+		querystring = build_querystring(named_g_mctx, dbi->allowxfr_q);
+		break;
+	case AUTHORITY:
+		querystring = build_querystring(named_g_mctx, dbi->authority_q);
+		break;
+	case FINDZONE:
+		querystring = build_querystring(named_g_mctx, dbi->findzone_q);
+		break;
+	case LOOKUP:
+		querystring = build_querystring(named_g_mctx, dbi->lookup_q);
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "odbc_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	/* if the querystring is null, Bummer, outta RAM.  UPGRADE TIME!!!   */
+	if (querystring == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	/* output the full query string during debug so we can see */
+	/* what lame error the query has. */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1), "\nQuery String: %s\n", querystring);
+
+	/* attempt query up to 3 times. */
+	for (j = 0; j < 3; j++) {
+		/* try to get result set */
+		sqlRes = SQLExecDirect(((odbc_db_t *)dbi->dbconn)->stmnt,
+				       (SQLCHAR *)querystring,
+				       (SQLINTEGER)strlen(querystring));
+
+		/* if error, reset DB connection */
+		if (!sqlOK(sqlRes)) {
+			/* close cursor */
+			SQLCloseCursor(((odbc_db_t *)dbi->dbconn)->stmnt);
+			/* attempt to reconnect */
+			result = odbc_connect((odbc_instance_t *)dbdata,
+					      (odbc_db_t **)&(dbi->dbconn));
+			/* check if we reconnected */
+			if (result != ISC_R_SUCCESS) {
+				break;
+			}
+			/* in case this is the last time through the loop */
+			result = ISC_R_FAILURE;
+		} else {
+			result = ISC_R_SUCCESS;
+			/* return dbi */
+			*r_dbi = dbi;
+			/* result set ok, break loop */
+			break;
+		}
+	} /* end for loop */
+
+cleanup: /* it's always good to cleanup after yourself */
+
+	/* free dbi->zone string */
+	if (dbi->zone != NULL) {
+		isc_mem_free(named_g_mctx, dbi->zone);
+	}
+
+	/* free dbi->record string */
+	if (dbi->record != NULL) {
+		isc_mem_free(named_g_mctx, dbi->record);
+	}
+
+	/* free dbi->client string */
+	if (dbi->client != NULL) {
+		isc_mem_free(named_g_mctx, dbi->client);
+	}
+
+	/* if we are done using this dbi, release the lock */
+	if (result != ISC_R_SUCCESS) {
+		isc_mutex_unlock(&dbi->instance_lock);
+	}
+
+	/* release query string */
+	if (querystring != NULL) {
+		isc_mem_free(named_g_mctx, querystring);
+	}
+
+	/* return result */
+	return (result);
+}
+
+/*%
+ * Gets a single field from the ODBC statement.  The memory for the
+ * returned data is dynamically allocated.  If this method is successful
+ * it is the responsibility of the caller to free the memory using
+ * isc_mem_free(named_g_mctx, *ptr);
+ */
+
+static isc_result_t
+odbc_getField(SQLHSTMT *stmnt, SQLSMALLINT field, char **data) {
+	SQLLEN size;
+
+	REQUIRE(data != NULL && *data == NULL);
+
+	if (sqlOK(SQLColAttribute(stmnt, field, SQL_DESC_DISPLAY_SIZE, NULL, 0,
+				  NULL, &size)) &&
+	    size > 0)
+	{
+		*data = isc_mem_allocate(named_g_mctx, size + 1);
+		if (data != NULL) {
+			if (sqlOK(SQLGetData(stmnt, field, SQL_C_CHAR, *data,
+					     size + 1, &size)))
+			{
+				return (ISC_R_SUCCESS);
+			}
+			isc_mem_free(named_g_mctx, *data);
+		}
+	}
+	return (ISC_R_FAILURE);
+}
+
+/*%
+ * Gets multiple fields from the ODBC statement.  The memory for the
+ * returned data is dynamically allocated.  If this method is successful
+ * it is the responsibility of the caller to free the memory using
+ * isc_mem_free(named_g_mctx, *ptr);
+ */
+
+static isc_result_t
+odbc_getManyFields(SQLHSTMT *stmnt, SQLSMALLINT startField,
+		   SQLSMALLINT endField, char **retData) {
+	isc_result_t result;
+	SQLLEN size;
+	int totSize = 0;
+	SQLSMALLINT i;
+	int j = 0;
+	char *data;
+
+	REQUIRE(retData != NULL && *retData == NULL);
+	REQUIRE(startField > 0 && startField <= endField);
+
+	/* determine how large the data is */
+	for (i = startField; i <= endField; i++) {
+		if (sqlOK(SQLColAttribute(stmnt, i, SQL_DESC_DISPLAY_SIZE, NULL,
+					  0, NULL, &size)) &&
+		    size > 0)
+		{
+			{
+				/* always allow for a " " (space) character */
+				totSize += (size + 1);
+				/* after the data item */
+			}
+		}
+	}
+
+	if (totSize < 1) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* allow for a "\n" at the end of the string/ */
+	data = isc_mem_allocate(named_g_mctx, ++totSize);
+
+	result = ISC_R_FAILURE;
+
+	/* get the data and concat all fields into a large string */
+	for (i = startField; i <= endField; i++) {
+		if (sqlOK(SQLGetData(stmnt, i, SQL_C_CHAR, &(data[j]),
+				     totSize - j, &size)))
+		{
+			if (size > 0) {
+				j += size;
+				data[j++] = ' ';
+				data[j] = '\0';
+				result = ISC_R_SUCCESS;
+			}
+		} else {
+			isc_mem_free(named_g_mctx, data);
+			return (ISC_R_FAILURE);
+		}
+	}
+
+	if (result != ISC_R_SUCCESS) {
+		isc_mem_free(named_g_mctx, data);
+		return (result);
+	}
+
+	*retData = data;
+	return (ISC_R_SUCCESS);
+}
+
+/*%
+ * The processing of result sets for lookup and authority are
+ * exactly the same.  So that functionality has been moved
+ * into this function to minimize code.
+ */
+
+static isc_result_t
+odbc_process_rs(dns_sdlzlookup_t *lookup, dbinstance_t *dbi) {
+	isc_result_t result;
+	SQLSMALLINT fields;
+	SQLHSTMT *stmnt;
+	char *ttl_s;
+	char *type;
+	char *data;
+	char *endp;
+	int ttl;
+
+	REQUIRE(dbi != NULL);
+
+	stmnt = ((odbc_db_t *)(dbi->dbconn))->stmnt;
+
+	/* get number of columns */
+	if (!sqlOK(SQLNumResultCols(stmnt, &fields))) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to process result set");
+		result = ISC_R_FAILURE;
+		goto process_rs_cleanup;
+	}
+
+	/* get things ready for processing */
+	result = ISC_R_FAILURE;
+
+	while (sqlOK(SQLFetch(stmnt))) {
+		/* set to null for next pass through */
+		data = type = ttl_s = NULL;
+
+		switch (fields) {
+		case 1:
+			/*
+			 * one column in rs, it's the data field.  use
+			 * default type of A record, and default TTL
+			 * of 86400.  attempt to get data, & tell bind
+			 * about it.
+			 */
+			if ((result = odbc_getField(stmnt, 1, &data)) ==
+			    ISC_R_SUCCESS)
+			{
+				result = dns_sdlz_putrr(lookup, "a", 86400,
+							data);
+			}
+			break;
+		case 2:
+			/*
+			 * two columns, data field, and data type.
+			 * use default TTL of 86400.  attempt to get
+			 * DNS type & data, then tell bind about it.
+			 */
+			if ((result = odbc_getField(stmnt, 1, &type)) ==
+				    ISC_R_SUCCESS &&
+			    (result = odbc_getField(stmnt, 2, &data)) ==
+				    ISC_R_SUCCESS)
+			{
+				result = dns_sdlz_putrr(lookup, type, 86400,
+							data);
+			}
+			break;
+		default:
+			/*
+			 * 3 fields or more, concatenate the last ones
+			 * together.  attempt to get DNS ttl, type,
+			 * data then tell Bind about them.
+			 */
+			if ((result = odbc_getField(stmnt, 1, &ttl_s)) ==
+				    ISC_R_SUCCESS &&
+			    (result = odbc_getField(stmnt, 2, &type)) ==
+				    ISC_R_SUCCESS &&
+			    (result = odbc_getManyFields(
+				     stmnt, 3, fields, &data)) == ISC_R_SUCCESS)
+			{
+				/* try to convert ttl string to int */
+				ttl = strtol(ttl_s, &endp, 10);
+				/* failure converting ttl. */
+				if (*endp != '\0' || ttl < 0) {
+					isc_log_write(dns_lctx,
+						      DNS_LOGCATEGORY_DATABASE,
+						      DNS_LOGMODULE_DLZ,
+						      ISC_LOG_ERROR,
+						      "Odbc driver ttl must "
+						      "be a positive number");
+					result = ISC_R_FAILURE;
+				} else {
+					/*
+					 * successful converting TTL,
+					 * tell Bind everything
+					 */
+					result = dns_sdlz_putrr(lookup, type,
+								ttl, data);
+				}
+			} /* closes bid if () */
+		}	  /* closes switch(fields) */
+
+		/* clean up mem */
+		if (ttl_s != NULL) {
+			isc_mem_free(named_g_mctx, ttl_s);
+		}
+		if (type != NULL) {
+			isc_mem_free(named_g_mctx, type);
+		}
+		if (data != NULL) {
+			isc_mem_free(named_g_mctx, data);
+		}
+
+		/* I sure hope we were successful */
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "dns_sdlz_putrr returned error. "
+				      "Error code was: %s",
+				      isc_result_totext(result));
+			result = ISC_R_FAILURE;
+			goto process_rs_cleanup;
+		}
+	} /* closes while loop */
+
+process_rs_cleanup:
+
+	/* close cursor */
+	SQLCloseCursor(((odbc_db_t *)(dbi->dbconn))->stmnt);
+
+	/* free lock on dbi so someone else can use it. */
+	isc_mutex_unlock(&dbi->instance_lock);
+
+	return (result);
+}
+
+/*
+ * SDLZ interface methods
+ */
+
+/*% determine if the zone is supported by (in) the database */
+
+static isc_result_t
+odbc_findzone(void *driverarg, void *dbdata, const char *name,
+	      dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	/* run the query and get the result set from the database. */
+	/* if result != ISC_R_SUCCESS cursor and mutex already cleaned up. */
+	/* so we don't have to do it here. */
+	result = odbc_get_resultset(name, NULL, NULL, FINDZONE, dbdata, &dbi);
+
+	/* Check that we got a result set with data */
+	if (result == ISC_R_SUCCESS &&
+	    !sqlOK(SQLFetch(((odbc_db_t *)(dbi->dbconn))->stmnt)))
+	{
+		result = ISC_R_NOTFOUND;
+	}
+
+	if (dbi != NULL) {
+		/* get rid of result set, we are done with it. */
+		SQLCloseCursor(((odbc_db_t *)(dbi->dbconn))->stmnt);
+
+		/* free lock on dbi so someone else can use it. */
+		isc_mutex_unlock(&dbi->instance_lock);
+	}
+
+	return (result);
+}
+
+/*% Determine if the client is allowed to perform a zone transfer */
+static isc_result_t
+odbc_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		  const char *client) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+
+	UNUSED(driverarg);
+
+	/* first check if the zone is supported by the database. */
+	result = odbc_findzone(driverarg, dbdata, name, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	/*
+	 * if we get to this point we know the zone is supported by
+	 * the database.  the only questions now are is the zone
+	 * transfer is allowed for this client and did the config file
+	 * have an allow zone xfr query
+	 *
+	 * Run our query, and get a result set from the database.  if
+	 * result != ISC_R_SUCCESS cursor and mutex already cleaned
+	 * up, so we don't have to do it here.
+	 */
+	result = odbc_get_resultset(name, NULL, client, ALLOWXFR, dbdata, &dbi);
+
+	/* if we get "not implemented", send it along. */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+
+	/* Check that we got a result set with data */
+	if (result == ISC_R_SUCCESS &&
+	    !sqlOK(SQLFetch(((odbc_db_t *)(dbi->dbconn))->stmnt)))
+	{
+		result = ISC_R_NOPERM;
+	}
+
+	if (dbi != NULL) {
+		/* get rid of result set, we are done with it. */
+		SQLCloseCursor(((odbc_db_t *)(dbi->dbconn))->stmnt);
+
+		/* free lock on dbi so someone else can use it. */
+		isc_mutex_unlock(&dbi->instance_lock);
+	}
+
+	return (result);
+}
+
+/*%
+ * If the client is allowed to perform a zone transfer, the next order of
+ * business is to get all the nodes in the zone, so bind can respond to the
+ * query.
+ */
+
+static isc_result_t
+odbc_allnodes(const char *zone, void *driverarg, void *dbdata,
+	      dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	SQLHSTMT *stmnt;
+	SQLSMALLINT fields;
+	char *data;
+	char *type;
+	char *ttl_s;
+	int ttl;
+	char *host;
+	char *endp;
+
+	UNUSED(driverarg);
+
+	/* run the query and get the result set from the database. */
+	result = odbc_get_resultset(zone, NULL, NULL, ALLNODES, dbdata, &dbi);
+
+	/* if we get "not implemented", send it along */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to return "
+			      "result set for all nodes query");
+		return (ISC_R_FAILURE);
+	}
+
+	stmnt = ((odbc_db_t *)(dbi->dbconn))->stmnt;
+
+	/* get number of columns */
+	if (!sqlOK(SQLNumResultCols(stmnt, &fields))) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to process result set");
+		result = ISC_R_FAILURE;
+		goto allnodes_cleanup;
+	}
+
+	if (fields < 4) { /* gotta have at least 4 columns */
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver too few fields returned by "
+			      "all nodes query");
+		result = ISC_R_FAILURE;
+		goto allnodes_cleanup;
+	}
+
+	/* get things ready for processing */
+	result = ISC_R_FAILURE;
+
+	while (sqlOK(SQLFetch(stmnt))) {
+		/* set to null for next pass through */
+		data = host = type = ttl_s = NULL;
+
+		/*
+		 * attempt to get DNS ttl, type, host, data then tell
+		 * Bind about them
+		 */
+		if ((result = odbc_getField(stmnt, 1, &ttl_s)) ==
+			    ISC_R_SUCCESS &&
+		    (result = odbc_getField(stmnt, 2, &type)) ==
+			    ISC_R_SUCCESS &&
+		    (result = odbc_getField(stmnt, 3, &host)) ==
+			    ISC_R_SUCCESS &&
+		    (result = odbc_getManyFields(stmnt, 4, fields, &data)) ==
+			    ISC_R_SUCCESS)
+		{
+			/* convert ttl string to int */
+			ttl = strtol(ttl_s, &endp, 10);
+			/* failure converting ttl. */
+			if (*endp != '\0' || ttl < 0) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "Odbc driver ttl must be "
+					      "a positive number");
+				result = ISC_R_FAILURE;
+			} else {
+				/* successful converting TTL, tell Bind  */
+				result = dns_sdlz_putnamedrr(allnodes, host,
+							     type, ttl, data);
+			}
+		} /* closes big if () */
+
+		/* clean up mem */
+		if (ttl_s != NULL) {
+			isc_mem_free(named_g_mctx, ttl_s);
+		}
+		if (type != NULL) {
+			isc_mem_free(named_g_mctx, type);
+		}
+		if (host != NULL) {
+			isc_mem_free(named_g_mctx, host);
+		}
+		if (data != NULL) {
+			isc_mem_free(named_g_mctx, data);
+		}
+
+		/* if we weren't successful, log err msg */
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "dns_sdlz_putnamedrr returned error. "
+				      "Error code was: %s",
+				      isc_result_totext(result));
+			result = ISC_R_FAILURE;
+			goto allnodes_cleanup;
+		}
+	} /* closes while loop */
+
+allnodes_cleanup:
+
+	/* close cursor */
+	SQLCloseCursor(((odbc_db_t *)(dbi->dbconn))->stmnt);
+
+	/* free lock on dbi so someone else can use it. */
+	isc_mutex_unlock(&dbi->instance_lock);
+
+	return (result);
+}
+
+/*%
+ * if the lookup function does not return SOA or NS records for the zone,
+ * use this function to get that information for Bind.
+ */
+
+static isc_result_t
+odbc_authority(const char *zone, void *driverarg, void *dbdata,
+	       dns_sdlzlookup_t *lookup) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+
+	UNUSED(driverarg);
+
+	/* run the query and get the result set from the database. */
+	result = odbc_get_resultset(zone, NULL, NULL, AUTHORITY, dbdata, &dbi);
+	/* if we get "not implemented", send it along */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to return "
+			      "result set for authority query");
+		return (ISC_R_FAILURE);
+	}
+	/* lookup and authority result sets are processed in the same manner */
+	/* odbc_process_rs does the job for both functions. */
+	return (odbc_process_rs(lookup, dbi));
+}
+
+/*% if zone is supported, lookup up a (or multiple) record(s) in it */
+
+static isc_result_t
+odbc_lookup(const char *zone, const char *name, void *driverarg, void *dbdata,
+	    dns_sdlzlookup_t *lookup, dns_clientinfomethods_t *methods,
+	    dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	/* run the query and get the result set from the database. */
+	result = odbc_get_resultset(zone, name, NULL, LOOKUP, dbdata, &dbi);
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver unable to return "
+			      "result set for lookup query");
+		return (ISC_R_FAILURE);
+	}
+	/* lookup and authority result sets are processed in the same manner */
+	/* odbc_process_rs does the job for both functions. */
+	return (odbc_process_rs(lookup, dbi));
+}
+
+/*%
+ * create an instance of the driver.  Remember, only 1 copy of the driver's
+ * code is ever loaded, the driver has to remember which context it's
+ * operating in.  This is done via use of the dbdata argument which is
+ * passed into all query functions.
+ */
+static isc_result_t
+odbc_create(const char *dlzname, unsigned int argc, char *argv[],
+	    void *driverarg, void **dbdata) {
+	isc_result_t result;
+	odbc_instance_t *odbc_inst = NULL;
+	dbinstance_t *db = NULL;
+	SQLRETURN sqlRes;
+	int dbcount;
+	int i;
+	char *endp;
+
+	UNUSED(dlzname);
+	UNUSED(driverarg);
+
+	/* if debugging, let user know we are multithreaded. */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1), "Odbc driver running multithreaded");
+
+	/* verify we have at least 5 arg's passed to the driver */
+	if (argc < 5) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver requires at least "
+			      "4 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* no more than 8 arg's should be passed to the driver */
+	if (argc > 8) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver cannot accept more than "
+			      "7 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* multithreaded build can have multiple DB connections */
+	/* check how many db connections we should create */
+	dbcount = strtol(argv[1], &endp, 10);
+	if (*endp != '\0' || dbcount < 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Odbc driver database connection count "
+			      "must be positive.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* allocate memory for odbc instance */
+	odbc_inst = isc_mem_get(named_g_mctx, sizeof(odbc_instance_t));
+	memset(odbc_inst, 0, sizeof(odbc_instance_t));
+
+	/* parse connection string and get parameters. */
+
+	/* get odbc database dsn - required */
+	odbc_inst->dsn = (SQLCHAR *)getParameterValue(argv[2], "dsn=");
+	if (odbc_inst->dsn == NULL) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "odbc driver requires a dns parameter.");
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+	/* get odbc database username */
+	/* if no username was passed, set odbc_inst.user = NULL; */
+	odbc_inst->user = (SQLCHAR *)getParameterValue(argv[2], "user=");
+
+	/* get odbc database password */
+	/* if no password was passed, set odbc_inst.pass = NULL; */
+	odbc_inst->pass = (SQLCHAR *)getParameterValue(argv[2], "pass=");
+
+	/* create odbc environment & set environment to ODBC V3 */
+	if (odbc_inst->sql_env == NULL) {
+		/* create environment handle */
+		sqlRes = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE,
+					&(odbc_inst->sql_env));
+		if (!sqlOK(sqlRes)) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
+				      "Odbc driver unable to allocate memory");
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+		/*set ODBC version = 3 */
+		sqlRes = SQLSetEnvAttr(odbc_inst->sql_env,
+				       SQL_ATTR_ODBC_VERSION,
+				       (void *)SQL_OV_ODBC3, 0);
+		if (!sqlOK(sqlRes)) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
+				      "Unable to configure ODBC environment");
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	}
+
+	/* allocate memory for database connection list */
+	odbc_inst->db = isc_mem_get(named_g_mctx, sizeof(db_list_t));
+
+	/* initialize DB connection list */
+	ISC_LIST_INIT(*odbc_inst->db);
+
+	/* create the appropriate number of database instances (DBI) */
+	/* append each new DBI to the end of the list */
+	for (i = 0; i < dbcount; i++) {
+		/* how many queries were passed in from config file? */
+		switch (argc) {
+		case 5:
+			result = build_sqldbinstance(named_g_mctx, NULL, NULL,
+						     NULL, argv[3], argv[4],
+						     NULL, &db);
+			break;
+		case 6:
+			result = build_sqldbinstance(named_g_mctx, NULL, NULL,
+						     argv[5], argv[3], argv[4],
+						     NULL, &db);
+			break;
+		case 7:
+			result = build_sqldbinstance(named_g_mctx, argv[6],
+						     NULL, argv[5], argv[3],
+						     argv[4], NULL, &db);
+			break;
+		case 8:
+			result = build_sqldbinstance(named_g_mctx, argv[6],
+						     argv[7], argv[5], argv[3],
+						     argv[4], NULL, &db);
+			break;
+		default:
+			/* not really needed, should shut up compiler. */
+			result = ISC_R_FAILURE;
+		}
+
+		/* unsuccessful?, log err msg and cleanup. */
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Odbc driver could not create "
+				      "database instance object.");
+			goto cleanup;
+		}
+
+		/* when multithreaded, build a list of DBI's */
+		ISC_LINK_INIT(db, link);
+		ISC_LIST_APPEND(*odbc_inst->db, db, link);
+
+		result = odbc_connect(odbc_inst, (odbc_db_t **)&(db->dbconn));
+
+		if (result != ISC_R_SUCCESS) {
+			/*
+			 * if multi threaded, let user know which
+			 * connection failed.  user could be
+			 * attempting to create 10 db connections and
+			 * for some reason the db backend only allows
+			 * 9.
+			 */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Odbc driver failed to create database "
+				      "connection number %u after 3 attempts",
+				      i + 1);
+			goto cleanup;
+		}
+
+		/* set DB = null for next loop through. */
+		db = NULL;
+	} /* end for loop */
+
+	/* set dbdata to the odbc_instance we created. */
+	*dbdata = odbc_inst;
+
+	/* hey, we got through all of that ok, return success. */
+	return (ISC_R_SUCCESS);
+
+cleanup:
+
+	destroy_odbc_instance(odbc_inst);
+
+	return (result);
+}
+
+/*%
+ * destroy an instance of the driver.  Remember, only 1 copy of the driver's
+ * code is ever loaded, the driver has to remember which context it's
+ * operating in.  This is done via use of the dbdata argument.
+ * so we really only need to clean it up since we are not using driverarg.
+ */
+
+static void
+odbc_destroy(void *driverarg, void *dbdata) {
+	UNUSED(driverarg);
+
+	destroy_odbc_instance((odbc_instance_t *)dbdata);
+}
+
+/* pointers to all our runtime methods. */
+/* this is used during driver registration */
+/* i.e. in dlz_odbc_init below. */
+static dns_sdlzmethods_t dlz_odbc_methods = {
+	odbc_create,
+	odbc_destroy,
+	odbc_findzone,
+	odbc_lookup,
+	odbc_authority,
+	odbc_allnodes,
+	odbc_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_odbc_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ odbc driver.");
+
+	/*
+	 * Driver is always threadsafe.  When multithreaded all
+	 * functions use multithreaded code.  When not multithreaded,
+	 * all functions can only be entered once, but only 1 thread
+	 * of operation is available in Bind.  So everything is still
+	 * threadsafe.
+	 */
+	result = dns_sdlzregister("odbc", &dlz_odbc_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA |
+					  DNS_SDLZFLAG_THREADSAFE,
+				  named_g_mctx, &dlz_odbc);
+	/* if we can't register the driver, there are big problems. */
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_odbc_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ odbc driver.");
+
+	/* unregister the driver. */
+	if (dlz_odbc != NULL) {
+		dns_sdlzunregister(&dlz_odbc);
+	}
+}
+
+#endif /* ifdef DLZ_ODBC */
diff --git a/contrib/dlz/drivers/dlz_postgres_driver.c b/contrib/dlz/drivers/dlz_postgres_driver.c
new file mode 100644
index 0000000..d960c3f
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_postgres_driver.c
@@ -0,0 +1,1240 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_POSTGRES
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_postgres_driver.h>
+#include <dlz/sdlz_helper.h>
+#include <named/globals.h>
+
+/* temporarily include time. */
+#include <libpq-fe.h>
+#include <time.h>
+
+static dns_sdlzimplementation_t *dlz_postgres = NULL;
+
+#define dbc_search_limit 30
+#define ALLNODES	 1
+#define ALLOWXFR	 2
+#define AUTHORITY	 3
+#define FINDZONE	 4
+#define LOOKUP		 5
+
+/*
+ * Private methods
+ */
+
+/* ---------------
+ * Escaping arbitrary strings to get valid SQL strings/identifiers.
+ *
+ * Replaces "\\" with "\\\\" and "'" with "''".
+ * length is the length of the buffer pointed to by
+ * from.  The buffer at to must be at least 2*length + 1 characters
+ * long.  A terminating NUL character is written.
+ *
+ * NOTICE!!!
+ * This function was borrowed directly from PostgreSQL's libpq.
+ * The function was originally called PQescapeString and renamed
+ * to postgres_makesafe to avoid a naming collision.
+ * PQescapeString is a new function made available in Postgres 7.2.
+ * For some reason the function is not properly exported on Win32
+ * builds making the function unavailable on Windows.  Also, since
+ * this function is new it would require building this driver with
+ * the libpq 7.2.  By borrowing this function the Windows problem
+ * is solved, and the dependence on libpq 7.2 is removed.  Libpq is
+ * still required of course, but an older version should work now too.
+ *
+ * The copyright statements from the original file containing this
+ * function are included below:
+ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ * ---------------
+ */
+
+static size_t
+postgres_makesafe(char *to, const char *from, size_t length) {
+	const char *source = from;
+	char *target = to;
+	unsigned int remaining = length;
+
+	while (remaining > 0) {
+		switch (*source) {
+		case '\\':
+			*target = '\\';
+			target++;
+			*target = '\\';
+			/* target and remaining are updated below. */
+			break;
+
+		case '\'':
+			*target = '\'';
+			target++;
+			*target = '\'';
+			/* target and remaining are updated below. */
+			break;
+
+		default:
+			*target = *source;
+			/* target and remaining are updated below. */
+		}
+		source++;
+		target++;
+		remaining--;
+	}
+
+	/* Write the terminating NUL character. */
+	*target = '\0';
+
+	return (target - to);
+}
+
+/*%
+ * Properly cleans up a list of database instances.
+ * This function is only used when the driver is compiled for
+ * multithreaded operation.
+ */
+static void
+postgres_destroy_dblist(db_list_t *dblist) {
+	dbinstance_t *ndbi = NULL;
+	dbinstance_t *dbi = NULL;
+
+	/* get the first DBI in the list */
+	ndbi = ISC_LIST_HEAD(*dblist);
+
+	/* loop through the list */
+	while (ndbi != NULL) {
+		dbi = ndbi;
+		/* get the next DBI in the list */
+		ndbi = ISC_LIST_NEXT(dbi, link);
+		/* release DB connection */
+		if (dbi->dbconn != NULL) {
+			PQfinish((PGconn *)dbi->dbconn);
+		}
+		/* release all memory that comprised a DBI */
+		destroy_sqldbinstance(dbi);
+	}
+	/* release memory for the list structure */
+	isc_mem_put(named_g_mctx, dblist, sizeof(db_list_t));
+}
+
+/*%
+ * Loops through the list of DB instances, attempting to lock
+ * on the mutex.  If successful, the DBI is reserved for use
+ * and the thread can perform queries against the database.
+ * If the lock fails, the next one in the list is tried.
+ * looping continues until a lock is obtained, or until
+ * the list has been searched dbc_search_limit times.
+ * This function is only used when the driver is compiled for
+ * multithreaded operation.
+ */
+
+static dbinstance_t *
+postgres_find_avail_conn(db_list_t *dblist) {
+	dbinstance_t *dbi = NULL;
+	dbinstance_t *head;
+	int count = 0;
+
+	/* get top of list */
+	head = dbi = ISC_LIST_HEAD(*dblist);
+
+	/* loop through list */
+	while (count < dbc_search_limit) {
+		/* try to lock on the mutex */
+		if (isc_mutex_trylock(&dbi->instance_lock) == ISC_R_SUCCESS) {
+			return (dbi); /* success, return the DBI for use. */
+		}
+		/* not successful, keep trying */
+		dbi = ISC_LIST_NEXT(dbi, link);
+
+		/* check to see if we have gone to the top of the list. */
+		if (dbi == NULL) {
+			count++;
+			dbi = head;
+		}
+	}
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_INFO,
+		      "Postgres driver unable to find available connection "
+		      "after searching %d times",
+		      count);
+	return (NULL);
+}
+
+/*%
+ * Allocates memory for a new string, and then constructs the new
+ * string by "escaping" the input string.  The new string is
+ * safe to be used in queries.  This is necessary because we cannot
+ * be sure of what types of strings are passed to us, and we don't
+ * want special characters in the string causing problems.
+ */
+
+static char *
+postgres_escape_string(const char *instr) {
+	char *outstr;
+	unsigned int len;
+
+	if (instr == NULL) {
+		return (NULL);
+	}
+
+	len = strlen(instr);
+
+	outstr = isc_mem_allocate(named_g_mctx, (2 * len * sizeof(char)) + 1);
+
+	postgres_makesafe(outstr, instr, len);
+	/* PQescapeString(outstr, instr, len); */
+
+	return (outstr);
+}
+
+/*%
+ * This function is the real core of the driver.   Zone, record
+ * and client strings are passed in (or NULL is passed if the
+ * string is not available).  The type of query we want to run
+ * is indicated by the query flag, and the dbdata object is passed
+ * passed in to.  dbdata really holds either:
+ *		1) a list of database instances (in multithreaded mode) OR
+ *		2) a single database instance (in single threaded mode)
+ * The function will construct the query and obtain an available
+ * database instance (DBI).  It will then run the query and hopefully
+ * obtain a result set.  Postgres is nice, in that once the result
+ * set is returned, we can make the db connection available for another
+ * thread to use, while this thread continues on.  So, the DBI is made
+ * available ASAP by unlocking the instance_lock after we have cleaned
+ * it up properly.
+ */
+static isc_result_t
+postgres_get_resultset(const char *zone, const char *record, const char *client,
+		       unsigned int query, void *dbdata, PGresult **rs) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	char *querystring = NULL;
+	unsigned int i = 0;
+	unsigned int j = 0;
+
+#if 0
+	/* temporarily get a unique thread # */
+	unsigned int dlz_thread_num = 1 +
+				      (int) (1000.0 * rand() /
+					     (RAND_MAX + 1.0));
+#endif /* if 0 */
+
+	REQUIRE(*rs == NULL);
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d Getting DBI", dlz_thread_num);
+#endif /* if 0 */
+
+	/* get db instance / connection */
+
+	/* find an available DBI from the list */
+	dbi = postgres_find_avail_conn((db_list_t *)dbdata);
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d Got DBI - checking query", dlz_thread_num);
+#endif /* if 0 */
+
+	/* if DBI is null, can't do anything else */
+	if (dbi == NULL) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* what type of query are we going to run? */
+	switch (query) {
+	case ALLNODES:
+		/*
+		 * if the query was not passed in from the config file
+		 * then we can't run it.  return not_implemented, so
+		 * it's like the code for that operation was never
+		 * built into the driver.... AHHH flexibility!!!
+		 */
+		if (dbi->allnodes_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case ALLOWXFR:
+		/* same as comments as ALLNODES */
+		if (dbi->allowxfr_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case AUTHORITY:
+		/* same as comments as ALLNODES */
+		if (dbi->authority_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case FINDZONE:
+		/* this is required.  It's the whole point of DLZ! */
+		if (dbi->findzone_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for findzone.  "
+				      "Findzone requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	case LOOKUP:
+		/* this is required.  It's also a major point of DLZ! */
+		if (dbi->lookup_q == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "No query specified for lookup.  "
+				      "Lookup requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "postgres_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d checked query", dlz_thread_num);
+#endif /* if 0 */
+
+	/*
+	 * was a zone string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (zone != NULL) {
+		dbi->zone = postgres_escape_string(zone);
+		if (dbi->zone == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->zone = NULL;
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d did zone", dlz_thread_num);
+#endif /* if 0 */
+
+	/*
+	 * was a record string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (record != NULL) {
+		dbi->record = postgres_escape_string(record);
+		if (dbi->record == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->record = NULL;
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d did record", dlz_thread_num);
+#endif /* if 0 */
+
+	/*
+	 * was a client string passed?  If so, make it safe for use in
+	 * queries.
+	 */
+	if (client != NULL) {
+		dbi->client = postgres_escape_string(client);
+		if (dbi->client == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else { /* no string passed, set the string pointer to NULL */
+		dbi->client = NULL;
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d did client", dlz_thread_num);
+#endif /* if 0 */
+
+	/*
+	 * what type of query are we going to run?
+	 * this time we build the actual query to run.
+	 */
+	switch (query) {
+	case ALLNODES:
+		querystring = build_querystring(named_g_mctx, dbi->allnodes_q);
+		break;
+	case ALLOWXFR:
+		querystring = build_querystring(named_g_mctx, dbi->allowxfr_q);
+		break;
+	case AUTHORITY:
+		querystring = build_querystring(named_g_mctx, dbi->authority_q);
+		break;
+	case FINDZONE:
+		querystring = build_querystring(named_g_mctx, dbi->findzone_q);
+		break;
+	case LOOKUP:
+		querystring = build_querystring(named_g_mctx, dbi->lookup_q);
+		break;
+	default:
+		/*
+		 * this should never happen.  If it does, the code is
+		 * screwed up!
+		 */
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "Incorrect query flag passed to "
+				 "postgres_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d built query", dlz_thread_num);
+#endif /* if 0 */
+
+	/* if the querystring is null, Bummer, outta RAM.  UPGRADE TIME!!!   */
+	if (querystring == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d query is '%s'", dlz_thread_num, querystring);
+#endif /* if 0 */
+
+	/*
+	 * output the full query string during debug so we can see
+	 * what lame error the query has.
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1), "\nQuery String: %s\n", querystring);
+
+	/* attempt query up to 3 times. */
+	for (j = 0; j < 3; j++) {
+#if 0
+		/* temporary logging message */
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "%d executing query for %d time",
+			      dlz_thread_num, j);
+#endif /* if 0 */
+		/* try to get result set */
+		*rs = PQexec((PGconn *)dbi->dbconn, querystring);
+		result = ISC_R_SUCCESS;
+		/*
+		 * if result set is null, reset DB connection, max 3
+		 * attempts.
+		 */
+		for (i = 0; *rs == NULL && i < 3; i++) {
+#if 0
+			/* temporary logging message */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "%d resetting connection",
+				      dlz_thread_num);
+#endif /* if 0 */
+			result = ISC_R_FAILURE;
+			PQreset((PGconn *)dbi->dbconn);
+			/* connection ok, break inner loop */
+			if (PQstatus((PGconn *)dbi->dbconn) == CONNECTION_OK) {
+				break;
+			}
+		}
+		/* result set ok, break outer loop */
+		if (PQresultStatus(*rs) == PGRES_TUPLES_OK) {
+#if 0
+			/* temporary logging message */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "%d rs ok", dlz_thread_num);
+#endif /* if 0 */
+			break;
+		} else {
+			/* we got a result set object, but it's not right. */
+#if 0
+			/* temporary logging message */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "%d clearing rs", dlz_thread_num);
+#endif				      /* if 0 */
+			PQclear(*rs); /* get rid of it */
+			/* in case this was the last attempt */
+			*rs = NULL;
+			result = ISC_R_FAILURE;
+		}
+	}
+
+cleanup:
+	/* it's always good to cleanup after yourself */
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d cleaning up", dlz_thread_num);
+#endif /* if 0 */
+
+	/* free dbi->zone string */
+	if (dbi->zone != NULL) {
+		isc_mem_free(named_g_mctx, dbi->zone);
+	}
+
+	/* free dbi->record string */
+	if (dbi->record != NULL) {
+		isc_mem_free(named_g_mctx, dbi->record);
+	}
+
+	/* free dbi->client string */
+	if (dbi->client != NULL) {
+		isc_mem_free(named_g_mctx, dbi->client);
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d unlocking mutex", dlz_thread_num);
+#endif /* if 0 */
+
+	/* release the lock so another thread can use this dbi */
+	isc_mutex_unlock(&dbi->instance_lock);
+
+	/* release query string */
+	if (querystring != NULL) {
+		isc_mem_free(named_g_mctx, querystring);
+	}
+
+#if 0
+	/* temporary logging message */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+		      "%d returning", dlz_thread_num);
+#endif /* if 0 */
+
+	/* return result */
+	return (result);
+}
+
+/*%
+ * The processing of result sets for lookup and authority are
+ * exactly the same.  So that functionality has been moved
+ * into this function to minimize code.
+ */
+
+static isc_result_t
+postgres_process_rs(dns_sdlzlookup_t *lookup, PGresult *rs) {
+	isc_result_t result;
+	unsigned int i;
+	unsigned int rows;
+	unsigned int fields;
+	unsigned int j;
+	unsigned int len;
+	char *tmpString;
+	char *endp;
+	int ttl;
+
+	rows = PQntuples(rs);	/* how many rows in result set */
+	fields = PQnfields(rs); /* how many columns in result set */
+	for (i = 0; i < rows; i++) {
+		switch (fields) {
+		case 1:
+			/*
+			 * one column in rs, it's the data field.  use
+			 * default type of A record, and default TTL
+			 * of 86400
+			 */
+			result = dns_sdlz_putrr(lookup, "a", 86400,
+						PQgetvalue(rs, i, 0));
+			break;
+		case 2:
+			/* two columns, data field, and data type.
+			 * use default TTL of 86400.
+			 */
+			result = dns_sdlz_putrr(lookup, PQgetvalue(rs, i, 0),
+						86400, PQgetvalue(rs, i, 1));
+			break;
+		case 3:
+			/* three columns, all data no defaults.
+			 * convert text to int, make sure it worked
+			 * right.
+			 */
+			ttl = strtol(PQgetvalue(rs, i, 0), &endp, 10);
+			if (*endp != '\0' || ttl < 0) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "Postgres driver ttl must be "
+					      "a positive number");
+			}
+			result = dns_sdlz_putrr(lookup, PQgetvalue(rs, i, 1),
+						ttl, PQgetvalue(rs, i, 2));
+			break;
+		default:
+			/*
+			 * more than 3 fields, concatenate the last
+			 * ones together.  figure out how long to make
+			 * string
+			 */
+			for (j = 2, len = 0; j < fields; j++) {
+				len += strlen(PQgetvalue(rs, i, j)) + 1;
+			}
+			/*
+			 * allocate string memory, allow for NULL to
+			 * term string
+			 */
+			tmpString = isc_mem_allocate(named_g_mctx, len + 1);
+			/* copy field to tmpString */
+			strcpy(tmpString, PQgetvalue(rs, i, 2));
+			/*
+			 * concat the rest of fields together, space
+			 * between each one.
+			 */
+			for (j = 3; j < fields; j++) {
+				strcat(tmpString, " ");
+				strcat(tmpString, PQgetvalue(rs, i, j));
+			}
+			/* convert text to int, make sure it worked right */
+			ttl = strtol(PQgetvalue(rs, i, 0), &endp, 10);
+			if (*endp != '\0' || ttl < 0) {
+				isc_log_write(dns_lctx,
+					      DNS_LOGCATEGORY_DATABASE,
+					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+					      "Postgres driver ttl must be "
+					      "a positive number");
+			}
+			/* ok, now tell Bind about it. */
+			result = dns_sdlz_putrr(lookup, PQgetvalue(rs, i, 1),
+						ttl, tmpString);
+			/* done, get rid of this thing. */
+			isc_mem_free(named_g_mctx, tmpString);
+		}
+		/* I sure hope we were successful */
+		if (result != ISC_R_SUCCESS) {
+			/* nope, get rid of the Result set, and log a msg */
+			PQclear(rs);
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "dns_sdlz_putrr returned error. "
+				      "Error code was: %s",
+				      isc_result_totext(result));
+			return (ISC_R_FAILURE);
+		}
+	}
+
+	/* free result set memory */
+	PQclear(rs);
+
+	/* if we did return results, we are successful */
+	if (rows > 0) {
+		return (ISC_R_SUCCESS);
+	}
+
+	/* empty result set, no data found */
+	return (ISC_R_NOTFOUND);
+}
+
+/*
+ * SDLZ interface methods
+ */
+
+/*% determine if the zone is supported by (in) the database */
+
+static isc_result_t
+postgres_findzone(void *driverarg, void *dbdata, const char *name,
+		  dns_clientinfomethods_t *methods,
+		  dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	PGresult *rs = NULL;
+	unsigned int rows;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	/* run the query and get the result set from the database. */
+	result = postgres_get_resultset(name, NULL, NULL, FINDZONE, dbdata,
+					&rs);
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			PQclear(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver unable to return "
+			      "result set for findzone query");
+		return (ISC_R_FAILURE);
+	}
+	/* count how many rows in result set */
+	rows = PQntuples(rs);
+	/* get rid of result set, we are done with it. */
+	PQclear(rs);
+
+	/* if we returned any rows, zone is supported. */
+	if (rows > 0) {
+		return (ISC_R_SUCCESS);
+	}
+
+	/* no rows returned, zone is not supported. */
+	return (ISC_R_NOTFOUND);
+}
+
+/*% Determine if the client is allowed to perform a zone transfer */
+static isc_result_t
+postgres_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		      const char *client) {
+	isc_result_t result;
+	PGresult *rs = NULL;
+	unsigned int rows;
+	UNUSED(driverarg);
+
+	/* first check if the zone is supported by the database. */
+	result = postgres_findzone(driverarg, dbdata, name, NULL, NULL);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_NOTFOUND);
+	}
+
+	/*
+	 * if we get to this point we know the zone is supported by
+	 * the database the only questions now are is the zone
+	 * transfer is allowed for this client and did the config file
+	 * have an allow zone xfr query.
+	 *
+	 * Run our query, and get a result set from the database.
+	 */
+	result = postgres_get_resultset(name, NULL, client, ALLOWXFR, dbdata,
+					&rs);
+	/* if we get "not implemented", send it along. */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			PQclear(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver unable to return "
+			      "result set for allow xfr query");
+		return (ISC_R_FAILURE);
+	}
+	/* count how many rows in result set */
+	rows = PQntuples(rs);
+	/* get rid of result set, we are done with it. */
+	PQclear(rs);
+
+	/* if we returned any rows, zone xfr is allowed. */
+	if (rows > 0) {
+		return (ISC_R_SUCCESS);
+	}
+
+	/* no rows returned, zone xfr not allowed */
+	return (ISC_R_NOPERM);
+}
+
+/*%
+ * If the client is allowed to perform a zone transfer, the next order of
+ * business is to get all the nodes in the zone, so bind can respond to the
+ * query.
+ */
+static isc_result_t
+postgres_allnodes(const char *zone, void *driverarg, void *dbdata,
+		  dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result;
+	PGresult *rs = NULL;
+	unsigned int i;
+	unsigned int rows;
+	unsigned int fields;
+	unsigned int j;
+	unsigned int len;
+	char *tmpString;
+	char *endp;
+	int ttl;
+
+	UNUSED(driverarg);
+
+	/* run the query and get the result set from the database. */
+	result = postgres_get_resultset(zone, NULL, NULL, ALLNODES, dbdata,
+					&rs);
+	/* if we get "not implemented", send it along */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			PQclear(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver unable to return "
+			      "result set for all nodes query");
+		return (ISC_R_FAILURE);
+	}
+
+	rows = PQntuples(rs);	/* how many rows in result set */
+	fields = PQnfields(rs); /* how many columns in result set */
+	for (i = 0; i < rows; i++) {
+		if (fields < 4) { /* gotta have at least 4 columns */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Postgres driver too few fields "
+				      "returned by all nodes query");
+		}
+		/* convert text to int, make sure it worked right  */
+		ttl = strtol(PQgetvalue(rs, i, 0), &endp, 10);
+		if (*endp != '\0' || ttl < 0) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Postgres driver ttl must be "
+				      "a positive number");
+		}
+		if (fields == 4) {
+			/* tell Bind about it. */
+			result = dns_sdlz_putnamedrr(allnodes,
+						     PQgetvalue(rs, i, 2),
+						     PQgetvalue(rs, i, 1), ttl,
+						     PQgetvalue(rs, i, 3));
+		} else {
+			/*
+			 * more than 4 fields, concatonat the last
+			 * ones together.  figure out how long to make
+			 * string
+			 */
+			for (j = 3, len = 0; j < fields; j++) {
+				len += strlen(PQgetvalue(rs, i, j)) + 1;
+			}
+			/* allocate memory, allow for NULL to term string */
+			tmpString = isc_mem_allocate(named_g_mctx, len + 1);
+			/* copy this field to tmpString */
+			strcpy(tmpString, PQgetvalue(rs, i, 3));
+			/* concatenate the rest, with spaces between */
+			for (j = 4; j < fields; j++) {
+				strcat(tmpString, " ");
+				strcat(tmpString, PQgetvalue(rs, i, j));
+			}
+			/* tell Bind about it. */
+			result = dns_sdlz_putnamedrr(
+				allnodes, PQgetvalue(rs, i, 2),
+				PQgetvalue(rs, i, 1), ttl, tmpString);
+			isc_mem_free(named_g_mctx, tmpString);
+		}
+		/* if we weren't successful, log err msg */
+		if (result != ISC_R_SUCCESS) {
+			PQclear(rs);
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "dns_sdlz_putnamedrr returned error. "
+				      "Error code was: %s",
+				      isc_result_totext(result));
+			return (ISC_R_FAILURE);
+		}
+	}
+
+	/* free result set memory */
+	PQclear(rs);
+
+	/* if we did return results, we are successful */
+	if (rows > 0) {
+		return (ISC_R_SUCCESS);
+	}
+
+	/* empty result set, no data found */
+	return (ISC_R_NOTFOUND);
+}
+
+/*%
+ * if the lookup function does not return SOA or NS records for the zone,
+ * use this function to get that information for Bind.
+ */
+
+static isc_result_t
+postgres_authority(const char *zone, void *driverarg, void *dbdata,
+		   dns_sdlzlookup_t *lookup) {
+	isc_result_t result;
+	PGresult *rs = NULL;
+
+	UNUSED(driverarg);
+
+	/* run the query and get the result set from the database. */
+	result = postgres_get_resultset(zone, NULL, NULL, AUTHORITY, dbdata,
+					&rs);
+	/* if we get "not implemented", send it along */
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			PQclear(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver unable to return "
+			      "result set for authority query");
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * lookup and authority result sets are processed in the same
+	 * manner postgres_process_rs does the job for both
+	 * functions.
+	 */
+	return (postgres_process_rs(lookup, rs));
+}
+
+/*% if zone is supported, lookup up a (or multiple) record(s) in it */
+static isc_result_t
+postgres_lookup(const char *zone, const char *name, void *driverarg,
+		void *dbdata, dns_sdlzlookup_t *lookup,
+		dns_clientinfomethods_t *methods,
+		dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	PGresult *rs = NULL;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	/* run the query and get the result set from the database. */
+	result = postgres_get_resultset(zone, name, NULL, LOOKUP, dbdata, &rs);
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			PQclear(rs);
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver unable to "
+			      "return result set for lookup query");
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * lookup and authority result sets are processed in the same
+	 * manner postgres_process_rs does the job for both functions.
+	 */
+	return (postgres_process_rs(lookup, rs));
+}
+
+/*%
+ * create an instance of the driver.  Remember, only 1 copy of the driver's
+ * code is ever loaded, the driver has to remember which context it's
+ * operating in.  This is done via use of the dbdata argument which is
+ * passed into all query functions.
+ */
+static isc_result_t
+postgres_create(const char *dlzname, unsigned int argc, char *argv[],
+		void *driverarg, void **dbdata) {
+	isc_result_t result;
+	dbinstance_t *dbi = NULL;
+	unsigned int j;
+
+	/* if multi-threaded, we need a few extra variables. */
+	int dbcount;
+	db_list_t *dblist = NULL;
+	int i;
+	char *endp;
+
+	UNUSED(driverarg);
+	UNUSED(dlzname);
+
+	/* seed random # generator */
+	srand((unsigned)time(NULL));
+
+	/* if debugging, let user know we are multithreaded. */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(1),
+		      "Postgres driver running multithreaded");
+
+	/* verify we have at least 5 arg's passed to the driver */
+	if (argc < 5) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver requires at least "
+			      "4 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* no more than 8 arg's should be passed to the driver */
+	if (argc > 8) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver cannot accept more than "
+			      "7 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* multithreaded build can have multiple DB connections */
+
+	/* check how many db connections we should create */
+	dbcount = strtol(argv[1], &endp, 10);
+	if (*endp != '\0' || dbcount < 0) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Postgres driver database connection count "
+			      "must be positive.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* allocate memory for database connection list */
+	dblist = isc_mem_get(named_g_mctx, sizeof(db_list_t));
+
+	/* initialize DB connection list */
+	ISC_LIST_INIT(*dblist);
+
+	/*
+	 * create the appropriate number of database instances (DBI)
+	 * append each new DBI to the end of the list
+	 */
+	for (i = 0; i < dbcount; i++) {
+		/* how many queries were passed in from config file? */
+		switch (argc) {
+		case 5:
+			result = build_sqldbinstance(named_g_mctx, NULL, NULL,
+						     NULL, argv[3], argv[4],
+						     NULL, &dbi);
+			break;
+		case 6:
+			result = build_sqldbinstance(named_g_mctx, NULL, NULL,
+						     argv[5], argv[3], argv[4],
+						     NULL, &dbi);
+			break;
+		case 7:
+			result = build_sqldbinstance(named_g_mctx, argv[6],
+						     NULL, argv[5], argv[3],
+						     argv[4], NULL, &dbi);
+			break;
+		case 8:
+			result = build_sqldbinstance(named_g_mctx, argv[6],
+						     argv[7], argv[5], argv[3],
+						     argv[4], NULL, &dbi);
+			break;
+		default:
+			/* not really needed, should shut up compiler. */
+			result = ISC_R_FAILURE;
+		}
+
+		if (result == ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
+				      "Postgres driver created database "
+				      "instance object.");
+		} else { /* unsuccessful?, log err msg and cleanup. */
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Postgres driver could not create "
+				      "database instance object.");
+			goto cleanup;
+		}
+
+		/* when multithreaded, build a list of DBI's */
+		ISC_LINK_INIT(dbi, link);
+		ISC_LIST_APPEND(*dblist, dbi, link);
+
+		/* create and set db connection */
+		dbi->dbconn = PQconnectdb(argv[2]);
+		/*
+		 * if db connection cannot be created, log err msg and
+		 * cleanup.
+		 */
+		if (dbi->dbconn == NULL) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Postgres driver could not allocate "
+				      "memory for database connection");
+			goto cleanup;
+		}
+
+		/* if we cannot connect the first time, try 3 more times. */
+		for (j = 0;
+		     PQstatus((PGconn *)dbi->dbconn) != CONNECTION_OK && j < 3;
+		     j++)
+		{
+			PQreset((PGconn *)dbi->dbconn);
+		}
+
+		/*
+		 * if multi threaded, let user know which connection
+		 * failed.  user could be attempting to create 10 db
+		 * connections and for some reason the db backend only
+		 * allows 9
+		 */
+		if (PQstatus((PGconn *)dbi->dbconn) != CONNECTION_OK) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+				      "Postgres driver failed to create "
+				      "database connection number %u "
+				      "after 4 attempts",
+				      i + 1);
+			goto cleanup;
+		}
+
+		/* set DBI = null for next loop through. */
+		dbi = NULL;
+	} /* end for loop */
+
+	/* set dbdata to the list we created. */
+	*dbdata = dblist;
+
+	/* hey, we got through all of that ok, return success. */
+	return (ISC_R_SUCCESS);
+
+cleanup:
+
+	/*
+	 * if multithreaded, we could fail because only 1 connection
+	 * couldn't be made.  We should cleanup the other successful
+	 * connections properly.
+	 */
+	postgres_destroy_dblist(dblist);
+
+	return (ISC_R_FAILURE);
+}
+
+/*%
+ * destroy an instance of the driver.  Remember, only 1 copy of the driver's
+ * code is ever loaded, the driver has to remember which context it's
+ * operating in.  This is done via use of the dbdata argument.
+ * so we really only need to clean it up since we are not using driverarg.
+ */
+static void
+postgres_destroy(void *driverarg, void *dbdata) {
+	UNUSED(driverarg);
+	/* cleanup the list of DBI's */
+	postgres_destroy_dblist((db_list_t *)dbdata);
+}
+
+/* pointers to all our runtime methods. */
+/* this is used during driver registration */
+/* i.e. in dlz_postgres_init below. */
+static dns_sdlzmethods_t dlz_postgres_methods = {
+	postgres_create,
+	postgres_destroy,
+	postgres_findzone,
+	postgres_lookup,
+	postgres_authority,
+	postgres_allnodes,
+	postgres_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_postgres_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ postgres driver.");
+
+	/*
+	 * Driver is always threadsafe.  When multithreaded all
+	 * functions use multithreaded code.  When not multithreaded,
+	 * all functions can only be entered once, but only 1 thread
+	 * of operation is available in Bind.  So everything is still
+	 * threadsafe.
+	 */
+	result = dns_sdlzregister("postgres", &dlz_postgres_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA |
+					  DNS_SDLZFLAG_THREADSAFE,
+				  named_g_mctx, &dlz_postgres);
+	/* if we can't register the driver, there are big problems. */
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*%
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_postgres_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ postgres driver.");
+
+	/* unregister the driver. */
+	if (dlz_postgres != NULL) {
+		dns_sdlzunregister(&dlz_postgres);
+	}
+}
+
+#endif /* ifdef DLZ_POSTGRES */
diff --git a/contrib/dlz/drivers/dlz_stub_driver.c b/contrib/dlz/drivers/dlz_stub_driver.c
new file mode 100644
index 0000000..f2e6f5f
--- /dev/null
+++ b/contrib/dlz/drivers/dlz_stub_driver.c
@@ -0,0 +1,295 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#ifdef DLZ_STUB
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+#include <dns/sdlz.h>
+
+#include <dlz/dlz_stub_driver.h>
+#include <named/globals.h>
+
+static dns_sdlzimplementation_t *dlz_stub = NULL;
+
+typedef struct config_data {
+	char *myzone;
+	char *myname;
+	char *myip;
+	isc_mem_t *mctx;
+} config_data_t;
+
+/*
+ * SDLZ methods
+ */
+
+static isc_result_t
+stub_dlz_allnodes(const char *zone, void *driverarg, void *dbdata,
+		  dns_sdlzallnodes_t *allnodes) {
+	config_data_t *cd;
+	isc_result_t result;
+
+	UNUSED(zone);
+	UNUSED(driverarg);
+
+	cd = (config_data_t *)dbdata;
+
+	result = dns_sdlz_putnamedrr(allnodes, cd->myname, "soa", 86400,
+				     "web root.localhost. "
+				     "0 28800 7200 604800 86400");
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_FAILURE);
+	}
+	result = dns_sdlz_putnamedrr(allnodes, "ns", "ns", 86400, cd->myname);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_FAILURE);
+	}
+	result = dns_sdlz_putnamedrr(allnodes, cd->myname, "a", 1, cd->myip);
+	if (result != ISC_R_SUCCESS) {
+		return (ISC_R_FAILURE);
+	}
+	return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+stub_dlz_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+		      const char *client) {
+	config_data_t *cd;
+
+	UNUSED(driverarg);
+	UNUSED(client);
+
+	cd = (config_data_t *)dbdata;
+
+	if (strcmp(name, cd->myname) == 0) {
+		return (ISC_R_SUCCESS);
+	}
+	return (ISC_R_NOTFOUND);
+}
+
+static isc_result_t
+stub_dlz_authority(const char *zone, void *driverarg, void *dbdata,
+		   dns_sdlzlookup_t *lookup) {
+	isc_result_t result;
+	config_data_t *cd;
+
+	UNUSED(driverarg);
+
+	cd = (config_data_t *)dbdata;
+
+	if (strcmp(zone, cd->myzone) == 0) {
+		result = dns_sdlz_putsoa(lookup, cd->myname, "root.localhost.",
+					 0);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_FAILURE);
+		}
+
+		result = dns_sdlz_putrr(lookup, "ns", 86400, cd->myname);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_FAILURE);
+		}
+
+		return (ISC_R_SUCCESS);
+	}
+	return (ISC_R_NOTFOUND);
+}
+
+static isc_result_t
+stub_dlz_findzonedb(void *driverarg, void *dbdata, const char *name,
+		    dns_clientinfomethods_t *methods,
+		    dns_clientinfo_t *clientinfo) {
+	config_data_t *cd;
+
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	cd = (config_data_t *)dbdata;
+
+	/* Write info message to log */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "dlz_stub findzone looking for '%s'",
+		      name);
+
+	if (strcmp(cd->myzone, name) == 0) {
+		return (ISC_R_SUCCESS);
+	} else {
+		return (ISC_R_NOTFOUND);
+	}
+}
+
+static isc_result_t
+stub_dlz_lookup(const char *zone, const char *name, void *driverarg,
+		void *dbdata, dns_sdlzlookup_t *lookup,
+		dns_clientinfomethods_t *methods,
+		dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	config_data_t *cd;
+
+	UNUSED(zone);
+	UNUSED(driverarg);
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	cd = (config_data_t *)dbdata;
+
+	if (strcmp(name, cd->myname) == 0) {
+		result = dns_sdlz_putrr(lookup, "a", 1, cd->myip);
+		if (result != ISC_R_SUCCESS) {
+			return (ISC_R_FAILURE);
+		}
+
+		return (ISC_R_SUCCESS);
+	}
+	return (ISC_R_FAILURE);
+}
+
+static isc_result_t
+stub_dlz_create(const char *dlzname, unsigned int argc, char *argv[],
+		void *driverarg, void **dbdata) {
+	config_data_t *cd;
+
+	UNUSED(driverarg);
+
+	if (argc < 4) {
+		return (ISC_R_FAILURE);
+	}
+	/*
+	 * Write info message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_INFO,
+		      "Loading '%s' using DLZ_stub driver. "
+		      "Zone: %s, Name: %s IP: %s",
+		      dlzname, argv[1], argv[2], argv[3]);
+
+	cd = isc_mem_get(named_g_mctx, sizeof(config_data_t));
+	if ((cd) == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	memset(cd, 0, sizeof(config_data_t));
+
+	cd->myzone = isc_mem_strdup(named_g_mctx, argv[1]);
+
+	cd->myname = isc_mem_strdup(named_g_mctx, argv[2]);
+
+	cd->myip = isc_mem_strdup(named_g_mctx, argv[3]);
+
+	isc_mem_attach(named_g_mctx, &cd->mctx);
+
+	*dbdata = cd;
+
+	return (ISC_R_SUCCESS);
+}
+
+static void
+stub_dlz_destroy(void *driverarg, void *dbdata) {
+	config_data_t *cd;
+	isc_mem_t *mctx;
+
+	UNUSED(driverarg);
+
+	cd = (config_data_t *)dbdata;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unloading DLZ_stub driver.");
+
+	isc_mem_free(named_g_mctx, cd->myzone);
+	isc_mem_free(named_g_mctx, cd->myname);
+	isc_mem_free(named_g_mctx, cd->myip);
+	mctx = cd->mctx;
+	isc_mem_putanddetach(&mctx, cd, sizeof(config_data_t));
+}
+
+static dns_sdlzmethods_t dlz_stub_methods = {
+	stub_dlz_create,
+	stub_dlz_destroy,
+	stub_dlz_findzonedb,
+	stub_dlz_lookup,
+	stub_dlz_authority,
+	stub_dlz_allnodes,
+	stub_dlz_allowzonexfr,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+/*%
+ * Wrapper around dns_sdlzregister().
+ */
+isc_result_t
+dlz_stub_init(void) {
+	isc_result_t result;
+
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Registering DLZ_stub driver.");
+
+	result = dns_sdlzregister("dlz_stub", &dlz_stub_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA,
+				  named_g_mctx, &dlz_stub);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*
+ * Wrapper around dns_sdlzunregister().
+ */
+void
+dlz_stub_clear(void) {
+	/*
+	 * Write debugging message to log
+	 */
+	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		      ISC_LOG_DEBUG(2), "Unregistering DLZ_stub driver.");
+
+	if (dlz_stub != NULL) {
+		dns_sdlzunregister(&dlz_stub);
+	}
+}
+
+#endif /* ifdef DLZ_STUB */
diff --git a/contrib/dlz/drivers/include/.clang-format b/contrib/dlz/drivers/include/.clang-format
new file mode 120000
index 0000000..e919bba
--- /dev/null
+++ b/contrib/dlz/drivers/include/.clang-format
@@ -0,0 +1 @@
+../../../../.clang-format.headers
\ No newline at end of file
diff --git a/contrib/dlz/drivers/include/dlz/dlz_bdb_driver.h b/contrib/dlz/drivers/include/dlz/dlz_bdb_driver.h
new file mode 100644
index 0000000..afe903d
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_bdb_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_BDB_DRIVER_H
+#define DLZ_BDB_DRIVER_H
+
+isc_result_t
+dlz_bdb_init(void);
+
+void
+dlz_bdb_clear(void);
+
+#endif /* ifndef DLZ_BDB_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_bdbhpt_driver.h b/contrib/dlz/drivers/include/dlz/dlz_bdbhpt_driver.h
new file mode 100644
index 0000000..c4d151f
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_bdbhpt_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_BDBHPT_DRIVER_H
+#define DLZ_BDBHPT_DRIVER_H
+
+isc_result_t
+dlz_bdbhpt_init(void);
+
+void
+dlz_bdbhpt_clear(void);
+
+#endif /* ifndef DLZ_BDBHPT_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_dlopen_driver.h b/contrib/dlz/drivers/include/dlz/dlz_dlopen_driver.h
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_dlopen_driver.h
diff --git a/contrib/dlz/drivers/include/dlz/dlz_drivers.h b/contrib/dlz/drivers/include/dlz/dlz_drivers.h
new file mode 100644
index 0000000..f3f66c5
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_drivers.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2005  Internet Systems Consortium, Inc. ("ISC")
+ * 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.
+ */
+
+#ifndef DLZ_DRIVERS_H
+#define DLZ_DRIVERS_H 1
+
+/*! \file */
+
+isc_result_t
+dlz_drivers_init(void);
+
+void
+dlz_drivers_clear(void);
+
+#endif /* DLZ_DRIVERS_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_filesystem_driver.h b/contrib/dlz/drivers/include/dlz/dlz_filesystem_driver.h
new file mode 100644
index 0000000..dc83582
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_filesystem_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_FILESYSTEM_DRIVER_H
+#define DLZ_FILESYSTEM_DRIVER_H
+
+isc_result_t
+dlz_fs_init(void);
+
+void
+dlz_fs_clear(void);
+
+#endif /* ifndef DLZ_FILESYSTEM_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_ldap_driver.h b/contrib/dlz/drivers/include/dlz/dlz_ldap_driver.h
new file mode 100644
index 0000000..ec01d97
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_ldap_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_LDAP_DRIVER_H
+#define DLZ_LDAP_DRIVER_H
+
+isc_result_t
+dlz_ldap_init(void);
+
+void
+dlz_ldap_clear(void);
+
+#endif /* ifndef DLZ_LDAP_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_mysql_driver.h b/contrib/dlz/drivers/include/dlz/dlz_mysql_driver.h
new file mode 100644
index 0000000..b419482
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_mysql_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_MYSQL_DRIVER_H
+#define DLZ_MYSQL_DRIVER_H
+
+isc_result_t
+dlz_mysql_init(void);
+
+void
+dlz_mysql_clear(void);
+
+#endif /* ifndef DLZ_MYSQL_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_odbc_driver.h b/contrib/dlz/drivers/include/dlz/dlz_odbc_driver.h
new file mode 100644
index 0000000..023c746
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_odbc_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_ODBC_DRIVER_H
+#define DLZ_ODBC_DRIVER_H
+
+isc_result_t
+dlz_odbc_init(void);
+
+void
+dlz_odbc_clear(void);
+
+#endif /* ifndef DLZ_ODBC_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_postgres_driver.h b/contrib/dlz/drivers/include/dlz/dlz_postgres_driver.h
new file mode 100644
index 0000000..f0692f1
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_postgres_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_POSTGRES_DRIVER_H
+#define DLZ_POSTGRES_DRIVER_H
+
+isc_result_t
+dlz_postgres_init(void);
+
+void
+dlz_postgres_clear(void);
+
+#endif /* ifndef DLZ_POSTGRES_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/dlz_stub_driver.h b/contrib/dlz/drivers/include/dlz/dlz_stub_driver.h
new file mode 100644
index 0000000..bf9b90a
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/dlz_stub_driver.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef DLZ_STUB_DRIVER_H
+#define DLZ_STUB_DRIVER_H
+
+isc_result_t
+dlz_stub_init(void);
+
+void
+dlz_stub_clear(void);
+
+#endif /* ifndef DLZ_STUB_DRIVER_H */
diff --git a/contrib/dlz/drivers/include/dlz/sdlz_helper.h b/contrib/dlz/drivers/include/dlz/sdlz_helper.h
new file mode 100644
index 0000000..1ddf3b9
--- /dev/null
+++ b/contrib/dlz/drivers/include/dlz/sdlz_helper.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+#ifndef SDLZHELPER_H
+#define SDLZHELPER_H
+
+#include <stdbool.h>
+
+/*
+ * Types
+ */
+#define SDLZH_REQUIRE_CLIENT 0x01
+#define SDLZH_REQUIRE_QUERY  0x02
+#define SDLZH_REQUIRE_RECORD 0x04
+#define SDLZH_REQUIRE_ZONE   0x08
+
+typedef struct query_segment query_segment_t;
+typedef ISC_LIST(query_segment_t) query_list_t;
+typedef struct dbinstance dbinstance_t;
+typedef ISC_LIST(dbinstance_t) db_list_t;
+typedef struct driverinstance driverinstance_t;
+
+/*%
+ * a query segment is all the text between our special tokens
+ * special tokens are %zone%, %record%, %client%
+ */
+struct query_segment {
+	void	    *sql;
+	unsigned int strlen;
+	bool	     direct;
+	ISC_LINK(query_segment_t) link;
+};
+
+/*%
+ * a database instance contains everything we need for running
+ * a query against the database.  Using it each separate thread
+ * can dynamically construct a query and execute it against the
+ * database.  The "instance_lock" and locking code in the driver's
+ * make sure no two threads try to use the same DBI at a time.
+ */
+struct dbinstance {
+	void	     *dbconn;
+	query_list_t *allnodes_q;
+	query_list_t *allowxfr_q;
+	query_list_t *authority_q;
+	query_list_t *findzone_q;
+	query_list_t *lookup_q;
+	query_list_t *countzone_q;
+	char	     *query_buf;
+	char	     *zone;
+	char	     *record;
+	char	     *client;
+	isc_mem_t    *mctx;
+	isc_mutex_t   instance_lock;
+	ISC_LINK(dbinstance_t) link;
+};
+
+/*
+ * Method declarations
+ */
+
+/* see the code in sdlz_helper.c for more information on these methods */
+
+char *
+sdlzh_build_querystring(isc_mem_t *mctx, query_list_t *querylist);
+
+isc_result_t
+sdlzh_build_sqldbinstance(isc_mem_t *mctx, const char *allnodes_str,
+			  const char *allowxfr_str, const char *authority_str,
+			  const char *findzone_str, const char *lookup_str,
+			  const char *countzone_str, dbinstance_t **dbi);
+
+void
+sdlzh_destroy_sqldbinstance(dbinstance_t *dbi);
+
+char *
+sdlzh_get_parameter_value(isc_mem_t *mctx, const char *input, const char *key);
+
+/* Compatibility with existing DLZ drivers */
+
+#define build_querystring     sdlzh_build_querystring
+#define build_sqldbinstance   sdlzh_build_sqldbinstance
+#define destroy_sqldbinstance sdlzh_destroy_sqldbinstance
+
+#define getParameterValue(x, y) \
+	sdlzh_get_parameter_value(named_g_mctx, (x), (y))
+
+#endif /* SDLZHELPER_H */
diff --git a/contrib/dlz/drivers/rules.in b/contrib/dlz/drivers/rules.in
new file mode 100644
index 0000000..560c200
--- /dev/null
+++ b/contrib/dlz/drivers/rules.in
@@ -0,0 +1,50 @@
+# Copyright (C) 2005  Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
+
+dlz_drivers.@O@: ${DLZ_DRIVER_DIR}/dlz_drivers.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_drivers.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_drivers.c
+
+sdlz_helper.@O@: ${DLZ_DRIVER_DIR}/sdlz_helper.c ${DLZ_DRIVER_DIR}/include/dlz/sdlz_helper.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/sdlz_helper.c
+
+
+dlz_bdb_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_bdb_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_bdb_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_bdb_driver.c
+
+dlz_bdbhpt_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_bdbhpt_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_bdbhpt_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_bdbhpt_driver.c
+
+dlz_filesystem_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_filesystem_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_filesystem_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_filesystem_driver.c
+
+dlz_ldap_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_ldap_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_ldap_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_ldap_driver.c
+
+dlz_mysql_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_mysql_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_mysql_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_mysql_driver.c
+
+dlz_odbc_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_odbc_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_odbc_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_odbc_driver.c
+
+dlz_postgres_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_postgres_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_postgres_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_postgres_driver.c
+
+dlz_dlopen_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_dlopen_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_dlopen_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_dlopen_driver.c
+
+dlz_stub_driver.@O@: ${DLZ_DRIVER_DIR}/dlz_stub_driver.c ${DLZ_DRIVER_DIR}/include/dlz/dlz_stub_driver.h
+	${LIBTOOL_MODE_COMPILE} ${CC} ${ALL_CFLAGS} -c ${DLZ_DRIVER_DIR}/dlz_stub_driver.c
+
diff --git a/contrib/dlz/drivers/sdlz_helper.c b/contrib/dlz/drivers/sdlz_helper.c
new file mode 100644
index 0000000..96c2be7
--- /dev/null
+++ b/contrib/dlz/drivers/sdlz_helper.c
@@ -0,0 +1,468 @@
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ * 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.
+ */
+
+/*
+ * Copyright (C) 1999-2001, 2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ */
+
+#include <stdbool.h>
+
+#include <isc/mem.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/result.h>
+
+#include <dlz/sdlz_helper.h>
+
+/*
+ * sdlz helper methods
+ */
+
+/*%
+ * properly destroys a querylist by de-allocating the
+ * memory for each query segment, and then the list itself
+ */
+
+static void
+destroy_querylist(isc_mem_t *mctx, query_list_t **querylist) {
+	query_segment_t *tseg = NULL;
+	query_segment_t *nseg = NULL;
+
+	REQUIRE(mctx != NULL);
+
+	/* if query list is null, nothing to do */
+	if (*querylist == NULL) {
+		return;
+	}
+
+	/* start at the top of the list */
+	nseg = ISC_LIST_HEAD(**querylist);
+	while (nseg != NULL) { /* loop, until end of list */
+		tseg = nseg;
+		/*
+		 * free the query segment's text string but only if it
+		 * was really a query segment, and not a pointer to
+		 * %zone%, or %record%, or %client%
+		 */
+		if (tseg->sql != NULL && tseg->direct) {
+			isc_mem_free(mctx, tseg->sql);
+		}
+		/* get the next query segment, before we destroy this one. */
+		nseg = ISC_LIST_NEXT(nseg, link);
+		/* deallocate this query segment. */
+		isc_mem_put(mctx, tseg, sizeof(query_segment_t));
+	}
+	/* deallocate the query segment list */
+	isc_mem_put(mctx, *querylist, sizeof(query_list_t));
+}
+
+/*% constructs a query list by parsing a string into query segments */
+static isc_result_t
+build_querylist(isc_mem_t *mctx, const char *query_str, char **zone,
+		char **record, char **client, query_list_t **querylist,
+		unsigned int flags) {
+	isc_result_t result;
+	bool foundzone = false;
+	bool foundrecord = false;
+	bool foundclient = false;
+	char *free_me = NULL;
+	char *temp_str = NULL;
+	query_list_t *tql;
+	query_segment_t *tseg = NULL;
+	char *last = NULL;
+
+	REQUIRE(querylist != NULL && *querylist == NULL);
+	REQUIRE(mctx != NULL);
+
+	/* if query string is null, or zero length */
+	if (query_str == NULL || strlen(query_str) < 1) {
+		if ((flags & SDLZH_REQUIRE_QUERY) == 0) {
+			/* we don't need it were ok. */
+			return (ISC_R_SUCCESS);
+		} else {
+			/* we did need it, PROBLEM!!! */
+			return (ISC_R_FAILURE);
+		}
+	}
+
+	/* allocate memory for query list */
+	tql = isc_mem_get(mctx, sizeof(query_list_t));
+
+	/* initialize the query segment list */
+	ISC_LIST_INIT(*tql);
+
+	/* make a copy of query_str so we can chop it up */
+	free_me = temp_str = isc_mem_strdup(mctx, query_str);
+	/* couldn't make a copy, problem!! */
+	if (temp_str == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	/* loop through the string and chop it up */
+	for (;;) {
+		/*
+		 * Split string into tokens at '$'.
+		 */
+		const char *sql = strtok_r(temp_str, "$", &last);
+		if (sql == NULL) {
+			break;
+		}
+		temp_str = NULL;
+
+		/* allocate memory for tseg */
+		tseg = isc_mem_get(mctx, sizeof(query_segment_t));
+		tseg->sql = NULL;
+		tseg->direct = false;
+		/* initialize the query segment link */
+		ISC_LINK_INIT(tseg, link);
+		/* append the query segment to the list */
+		ISC_LIST_APPEND(*tql, tseg, link);
+
+		tseg->sql = isc_mem_strdup(mctx, sql);
+		/* tseg->sql points directly to a string. */
+		tseg->direct = true;
+		tseg->strlen = strlen(tseg->sql);
+
+		/* check if we encountered "$zone$" token */
+		if (strcasecmp(tseg->sql, "zone") == 0) {
+			/*
+			 * we don't really need, or want the "zone"
+			 * text, so get rid of it.
+			 */
+			isc_mem_free(mctx, tseg->sql);
+			/* set tseg->sql to in-direct zone string */
+			tseg->sql = zone;
+			tseg->strlen = 0;
+			/* tseg->sql points in-directly to a string */
+			tseg->direct = false;
+			foundzone = true;
+			/* check if we encountered "$record$" token */
+		} else if (strcasecmp(tseg->sql, "record") == 0) {
+			/*
+			 * we don't really need, or want the "record"
+			 * text, so get rid of it.
+			 */
+			isc_mem_free(mctx, tseg->sql);
+			/* set tseg->sql to in-direct record string */
+			tseg->sql = record;
+			tseg->strlen = 0;
+			/* tseg->sql points in-directly points to a string */
+			tseg->direct = false;
+			foundrecord = true;
+			/* check if we encountered "$client$" token */
+		} else if (strcasecmp(tseg->sql, "client") == 0) {
+			/*
+			 * we don't really need, or want the "client"
+			 * text, so get rid of it.
+			 */
+			isc_mem_free(mctx, tseg->sql);
+			/* set tseg->sql to in-direct record string */
+			tseg->sql = client;
+			tseg->strlen = 0;
+			/* tseg->sql points in-directly points to a string */
+			tseg->direct = false;
+			foundclient = true;
+		}
+	}
+
+	/* we don't need temp_str any more */
+	isc_mem_free(mctx, free_me);
+	/*
+	 * add checks later to verify zone and record are found if
+	 * necessary.
+	 */
+
+	/* if this query requires %client%, make sure we found it */
+	if (((flags & SDLZH_REQUIRE_CLIENT) != 0) && (!foundclient)) {
+		/* Write error message to log */
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Required token $client$ not found.");
+		result = ISC_R_FAILURE;
+		goto flag_fail;
+	}
+
+	/* if this query requires %record%, make sure we found it */
+	if (((flags & SDLZH_REQUIRE_RECORD) != 0) && (!foundrecord)) {
+		/* Write error message to log */
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Required token $record$ not found.");
+		result = ISC_R_FAILURE;
+		goto flag_fail;
+	}
+
+	/* if this query requires %zone%, make sure we found it */
+	if (((flags & SDLZH_REQUIRE_ZONE) != 0) && (!foundzone)) {
+		/* Write error message to log */
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Required token $zone$ not found.");
+		result = ISC_R_FAILURE;
+		goto flag_fail;
+	}
+
+	/* pass back the query list */
+	*querylist = (query_list_t *)tql;
+
+	/* return success */
+	return (ISC_R_SUCCESS);
+
+cleanup:
+	/* get rid of free_me */
+	if (free_me != NULL) {
+		isc_mem_free(mctx, free_me);
+	}
+
+flag_fail:
+	/* get rid of what was build of the query list */
+	destroy_querylist(mctx, &tql);
+	return (result);
+}
+
+/*%
+ * build a query string from query segments, and dynamic segments
+ * dynamic segments replace where the tokens %zone%, %record%, %client%
+ * used to be in our queries from named.conf
+ */
+char *
+sdlzh_build_querystring(isc_mem_t *mctx, query_list_t *querylist) {
+	query_segment_t *tseg = NULL;
+	unsigned int length = 0;
+	char *qs = NULL;
+
+	REQUIRE(mctx != NULL);
+	REQUIRE(querylist != NULL);
+
+	/* start at the top of the list */
+	tseg = ISC_LIST_HEAD(*querylist);
+	while (tseg != NULL) {
+		/*
+		 * if this is a query segment, use the
+		 * precalculated string length
+		 */
+		if (tseg->direct) {
+			length += tseg->strlen;
+		} else { /* calculate string length for dynamic segments. */
+			length += strlen(*(char **)tseg->sql);
+		}
+		/* get the next segment */
+		tseg = ISC_LIST_NEXT(tseg, link);
+	}
+
+	/* allocate memory for the string */
+	qs = isc_mem_allocate(mctx, length + 1);
+
+	*qs = 0;
+	/* start at the top of the list again */
+	tseg = ISC_LIST_HEAD(*querylist);
+	while (tseg != NULL) {
+		if (tseg->direct) {
+			/* query segments */
+			strcat(qs, tseg->sql);
+		} else {
+			/* dynamic segments */
+			strcat(qs, *(char **)tseg->sql);
+		}
+		/* get the next segment */
+		tseg = ISC_LIST_NEXT(tseg, link);
+	}
+
+	return (qs);
+}
+
+/*% constructs a sql dbinstance (DBI) */
+isc_result_t
+sdlzh_build_sqldbinstance(isc_mem_t *mctx, const char *allnodes_str,
+			  const char *allowxfr_str, const char *authority_str,
+			  const char *findzone_str, const char *lookup_str,
+			  const char *countzone_str, dbinstance_t **dbi) {
+	isc_result_t result;
+	dbinstance_t *db = NULL;
+
+	REQUIRE(dbi != NULL && *dbi == NULL);
+	REQUIRE(mctx != NULL);
+
+	/* allocate and zero memory for driver structure */
+	db = isc_mem_get(mctx, sizeof(dbinstance_t));
+	memset(db, 0, sizeof(dbinstance_t));
+	db->dbconn = NULL;
+	db->client = NULL;
+	db->record = NULL;
+	db->zone = NULL;
+	db->mctx = NULL;
+	db->query_buf = NULL;
+	db->allnodes_q = NULL;
+	db->allowxfr_q = NULL;
+	db->authority_q = NULL;
+	db->findzone_q = NULL;
+	db->countzone_q = NULL;
+	db->lookup_q = NULL;
+
+	/* attach to the memory context */
+	isc_mem_attach(mctx, &db->mctx);
+
+	/* initialize the reference count mutex */
+	isc_mutex_init(&db->instance_lock);
+
+	/* build the all nodes query list */
+	result = build_querylist(mctx, allnodes_str, &db->zone, &db->record,
+				 &db->client, &db->allnodes_q,
+				 SDLZH_REQUIRE_ZONE);
+	/* if unsuccessful, log err msg and cleanup */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Could not build all nodes query list");
+		goto cleanup;
+	}
+
+	/* build the allow zone transfer query list */
+	result = build_querylist(mctx, allowxfr_str, &db->zone, &db->record,
+				 &db->client, &db->allowxfr_q,
+				 SDLZH_REQUIRE_ZONE | SDLZH_REQUIRE_CLIENT);
+	/* if unsuccessful, log err msg and cleanup */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Could not build allow xfr query list");
+		goto cleanup;
+	}
+
+	/* build the authority query, query list */
+	result = build_querylist(mctx, authority_str, &db->zone, &db->record,
+				 &db->client, &db->authority_q,
+				 SDLZH_REQUIRE_ZONE);
+	/* if unsuccessful, log err msg and cleanup */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Could not build authority query list");
+		goto cleanup;
+	}
+
+	/* build findzone query, query list */
+	result = build_querylist(mctx, findzone_str, &db->zone, &db->record,
+				 &db->client, &db->findzone_q,
+				 SDLZH_REQUIRE_ZONE);
+	/* if unsuccessful, log err msg and cleanup */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Could not build find zone query list");
+		goto cleanup;
+	}
+
+	/* build countzone query, query list */
+	result = build_querylist(mctx, countzone_str, &db->zone, &db->record,
+				 &db->client, &db->countzone_q,
+				 SDLZH_REQUIRE_ZONE);
+	/* if unsuccessful, log err msg and cleanup */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Could not build count zone query list");
+		goto cleanup;
+	}
+
+	/* build lookup query, query list */
+	result = build_querylist(mctx, lookup_str, &db->zone, &db->record,
+				 &db->client, &db->lookup_q,
+				 SDLZH_REQUIRE_RECORD);
+	/* if unsuccessful, log err msg and cleanup */
+	if (result != ISC_R_SUCCESS) {
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
+			      "Could not build lookup query list");
+		goto cleanup;
+	}
+
+	/* pass back the db instance */
+	*dbi = (dbinstance_t *)db;
+
+	/* return success */
+	return (ISC_R_SUCCESS);
+
+cleanup:
+	/* destroy whatever was build of the db instance */
+	destroy_sqldbinstance(db);
+	/* return failure */
+	return (ISC_R_FAILURE);
+}
+
+void
+sdlzh_destroy_sqldbinstance(dbinstance_t *dbi) {
+	isc_mem_t *mctx;
+
+	/* save mctx for later */
+	mctx = dbi->mctx;
+
+	/* destroy any query lists we created */
+	destroy_querylist(mctx, &dbi->allnodes_q);
+	destroy_querylist(mctx, &dbi->allowxfr_q);
+	destroy_querylist(mctx, &dbi->authority_q);
+	destroy_querylist(mctx, &dbi->findzone_q);
+	destroy_querylist(mctx, &dbi->countzone_q);
+	destroy_querylist(mctx, &dbi->lookup_q);
+
+	/* get rid of the mutex */
+	(void)isc_mutex_destroy(&dbi->instance_lock);
+
+	/* return, and detach the memory */
+	isc_mem_putanddetach(&mctx, dbi, sizeof(dbinstance_t));
+}
+
+char *
+sdlzh_get_parameter_value(isc_mem_t *mctx, const char *input, const char *key) {
+	int keylen;
+	char *keystart;
+	char value[255];
+	int i;
+
+	if (key == NULL || input == NULL || strlen(input) < 1) {
+		return (NULL);
+	}
+
+	keylen = strlen(key);
+
+	if (keylen < 1) {
+		return (NULL);
+	}
+
+	keystart = strstr(input, key);
+
+	if (keystart == NULL) {
+		return (NULL);
+	}
+
+	REQUIRE(mctx != NULL);
+
+	for (i = 0; i < 255; i++) {
+		value[i] = keystart[keylen + i];
+		if (value[i] == ' ' || value[i] == '\0') {
+			value[i] = '\0';
+			break;
+		}
+	}
+
+	return (isc_mem_strdup(mctx, value));
+}