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

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

6 files changed, 1212 insertions, 0 deletions

diff --git a/contrib/dlz/modules/mysql/Makefile b/contrib/dlz/modules/mysql/Makefile
new file mode 100644
index 0000000..5d0904c
--- /dev/null
+++ b/contrib/dlz/modules/mysql/Makefile
@@ -0,0 +1,46 @@
+# Copyright 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 https://mozilla.org/MPL/2.0/.
+
+# Copyright (C) Stichting NLnet, Netherlands, stichting@nlnet.nl.
+#
+# The development of Dynamically Loadable Zones (DLZ) for Bind 9 was
+# conceived and contributed by Rob Butler.
+#
+# SPDX-License-Identifier: ISC and 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 STICHTING NLNET DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL STICHTING NLNET 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.
+
+prefix = /usr
+libdir = $(prefix)/lib/bind9
+
+CFLAGS += -fPIC -g -I../include $(shell mysql_config --cflags)
+MYSQL_LIBS=$(shell mysql_config --libs)
+
+all: dlz_mysql_dynamic.so
+
+dlz_dbi.o: ../common/dlz_dbi.c
+	$(CC) $(CFLAGS) -c ../common/dlz_dbi.c
+
+dlz_mysql_dynamic.so: dlz_mysql_dynamic.c dlz_dbi.o
+	$(CC) $(CFLAGS) -shared -o dlz_mysql_dynamic.so \
+		dlz_mysql_dynamic.c dlz_dbi.o $(MYSQL_LIBS)
+
+clean:
+	rm -f dlz_mysql_dynamic.so *.o
+
+install: dlz_mysql_dynamic.so
+	mkdir -p $(DESTDIR)$(libdir)
+	install dlz_mysql_dynamic.so $(DESTDIR)$(libdir)
diff --git a/contrib/dlz/modules/mysql/dlz_mysql_dynamic.c b/contrib/dlz/modules/mysql/dlz_mysql_dynamic.c
new file mode 100644
index 0000000..a6e0ebf
--- /dev/null
+++ b/contrib/dlz/modules/mysql/dlz_mysql_dynamic.c
@@ -0,0 +1,1071 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 and 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 https://mozilla.org/MPL/2.0/.
+ */
+
+/*
+ * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
+ *
+ * The development of Dynamically Loadable Zones (DLZ) for Bind 9 was
+ * conceived and contributed by Rob Butler.
+ *
+ * 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 THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
+ */
+
+/*
+ * This provides the externally loadable MySQL DLZ module, without
+ * update support
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mysql/mysql.h>
+
+#include <dlz_dbi.h>
+#include <dlz_list.h>
+#include <dlz_minimal.h>
+#include <dlz_pthread.h>
+
+#if !defined(MARIADB_BASE_VERSION) && MYSQL_VERSION_ID >= 80000
+typedef bool my_bool;
+#endif /* !defined(MARIADB_BASE_VERSION) && MYSQL_VERSION_ID >= 80000 */
+
+#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
+
+/*%
+ * Structure to hold everything needed by this "instance" of the MySQL
+ * module remember, the module code is only loaded once, but may have
+ * many separate instances.
+ */
+typedef struct {
+	db_list_t *db; /*%< handle to a list of DB */
+	int dbcount;
+
+	unsigned int flags;
+	char *dbname;
+	char *host;
+	char *user;
+	char *pass;
+	char *socket;
+	int port;
+
+	/* Helper functions from the dlz_dlopen driver */
+	log_t *log;
+	dns_sdlz_putrr_t *putrr;
+	dns_sdlz_putnamedrr_t *putnamedrr;
+	dns_dlz_writeablezone_t *writeable_zone;
+} mysql_instance_t;
+
+/* forward references */
+isc_result_t
+dlz_findzonedb(void *dbdata, const char *name, dns_clientinfomethods_t *methods,
+	       dns_clientinfo_t *clientinfo);
+
+void
+dlz_destroy(void *dbdata);
+
+static void
+b9_add_helper(mysql_instance_t *db, const char *helper_name, void *ptr);
+
+/*
+ * Private methods
+ */
+
+static void
+dlz_mysql_destroy(dbinstance_t *db) {
+	/* release DB connection */
+	if (db->dbconn != NULL) {
+		mysql_close((MYSQL *)db->dbconn);
+	}
+
+	/* destroy DB instance */
+	destroy_dbinstance(db);
+}
+
+/*%
+ * Properly cleans up a list of database instances.
+ * This function is only used when the module is compiled for
+ * multithreaded operation.
+ */
+static void
+dlz_mysql_destroy_dblist(db_list_t *dblist) {
+	dbinstance_t *ndbi = NULL;
+	dbinstance_t *dbi = NULL;
+
+	ndbi = DLZ_LIST_HEAD(*dblist);
+	while (ndbi != NULL) {
+		dbi = ndbi;
+		ndbi = DLZ_LIST_NEXT(dbi, link);
+
+		dlz_mysql_destroy(dbi);
+	}
+
+	/* release memory for the list structure */
+	free(dblist);
+}
+
+/*%
+ * 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 module is compiled for
+ * multithreaded operation.
+ */
+static dbinstance_t *
+mysql_find_avail_conn(mysql_instance_t *mysql) {
+	dbinstance_t *dbi = NULL, *head;
+	int count = 0;
+
+	/* get top of list */
+	head = dbi = DLZ_LIST_HEAD(*(mysql->db));
+
+	/* loop through list */
+	while (count < dbc_search_limit) {
+		/* try to lock on the mutex */
+		if (dlz_mutex_trylock(&dbi->lock) == 0) {
+			return (dbi); /* success, return the DBI for use. */
+		}
+		/* not successful, keep trying */
+		dbi = DLZ_LIST_NEXT(dbi, link);
+
+		/* check to see if we have gone to the top of the list. */
+		if (dbi == NULL) {
+			count++;
+			dbi = head;
+		}
+	}
+
+	mysql->log(ISC_LOG_INFO,
+		   "MySQL module 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 *
+mysqldrv_escape_string(MYSQL *mysql, const char *instr) {
+	char *outstr;
+	unsigned int len;
+
+	if (instr == NULL) {
+		return (NULL);
+	}
+
+	len = strlen(instr);
+	outstr = malloc((2 * len * sizeof(char)) + 1);
+	if (outstr == NULL) {
+		return (NULL);
+	}
+
+	mysql_real_escape_string(mysql, outstr, instr, len);
+
+	return (outstr);
+}
+
+/*%
+ * This function is the real core of the module.   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;
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+	char *querystring = NULL;
+	unsigned int i = 0;
+	unsigned int j = 0;
+	int qres = 0;
+
+	/* find an available DBI from the list */
+	dbi = mysql_find_avail_conn(db);
+
+	if (dbi == NULL) {
+		return (ISC_R_FAILURE);
+	}
+
+	/* what type of query are we going to run? */
+	switch (query) {
+	case ALLNODES:
+		if (dbi->allnodes_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case ALLOWXFR:
+		if (dbi->allowxfr_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case AUTHORITY:
+		if (dbi->authority_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case FINDZONE:
+		if (dbi->findzone_q == NULL) {
+			db->log(ISC_LOG_DEBUG(2), "No query specified for "
+						  "findzone.  "
+						  "Findzone requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	case COUNTZONE:
+		if (dbi->countzone_q == NULL) {
+			result = ISC_R_NOTIMPLEMENTED;
+			goto cleanup;
+		}
+		break;
+	case LOOKUP:
+		if (dbi->lookup_q == NULL) {
+			db->log(ISC_LOG_DEBUG(2), "No query specified for "
+						  "lookup.  "
+						  "Lookup requires a query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		break;
+	default:
+		db->log(ISC_LOG_ERROR, "Incorrect query flag passed to "
+				       "mysql_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	if (zone != NULL) {
+		if (dbi->zone != NULL) {
+			free(dbi->zone);
+		}
+
+		dbi->zone = mysqldrv_escape_string((MYSQL *)dbi->dbconn, zone);
+		if (dbi->zone == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else {
+		dbi->zone = NULL;
+	}
+
+	if (record != NULL) {
+		if (dbi->record != NULL) {
+			free(dbi->record);
+		}
+
+		dbi->record = mysqldrv_escape_string((MYSQL *)dbi->dbconn,
+						     record);
+		if (dbi->record == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else {
+		dbi->record = NULL;
+	}
+
+	if (client != NULL) {
+		if (dbi->client != NULL) {
+			free(dbi->client);
+		}
+
+		dbi->client = mysqldrv_escape_string((MYSQL *)dbi->dbconn,
+						     client);
+		if (dbi->client == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup;
+		}
+	} else {
+		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(dbi->allnodes_q);
+		break;
+	case ALLOWXFR:
+		querystring = build_querystring(dbi->allowxfr_q);
+		break;
+	case AUTHORITY:
+		querystring = build_querystring(dbi->authority_q);
+		break;
+	case FINDZONE:
+		querystring = build_querystring(dbi->findzone_q);
+		break;
+	case COUNTZONE:
+		querystring = build_querystring(dbi->countzone_q);
+		break;
+	case LOOKUP:
+		querystring = build_querystring(dbi->lookup_q);
+		break;
+	default:
+		db->log(ISC_LOG_ERROR, "Incorrect query flag passed to "
+				       "mysql_get_resultset");
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	if (querystring == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	/* output the full query string when debugging */
+	db->log(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; j < 4; j++) {
+			if (mysql_ping((MYSQL *)dbi->dbconn) == 0) {
+				break;
+			}
+		}
+	}
+
+	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:
+	if (dbi->zone != NULL) {
+		free(dbi->zone);
+		dbi->zone = NULL;
+	}
+	if (dbi->record != NULL) {
+		free(dbi->record);
+		dbi->record = NULL;
+	}
+	if (dbi->client != NULL) {
+		free(dbi->client);
+		dbi->client = NULL;
+	}
+
+	/* release the lock so another thread can use this dbi */
+	(void)dlz_mutex_unlock(&dbi->lock);
+
+	if (querystring != NULL) {
+		free(querystring);
+	}
+
+	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(mysql_instance_t *db, dns_sdlzlookup_t *lookup,
+		 MYSQL_RES *rs) {
+	isc_result_t result = ISC_R_NOTFOUND;
+	MYSQL_ROW row;
+	unsigned int fields;
+	unsigned int j;
+	char *tmpString;
+	char *endp;
+	int ttl;
+
+	fields = mysql_num_fields(rs); /* how many columns in result set */
+	row = mysql_fetch_row(rs);     /* get a row from the result set */
+	while (row != NULL) {
+		unsigned int len = 0;
+
+		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 = db->putrr(lookup, "a", 86400, safeGet(row[0]));
+			break;
+		case 2:
+			/*
+			 * two columns, data field, and data type.
+			 * use default TTL of 86400.
+			 */
+			result = db->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) {
+				db->log(ISC_LOG_ERROR, "MySQL module ttl must "
+						       "be "
+						       "a positive number");
+				return (ISC_R_FAILURE);
+			}
+
+			result = db->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; j < fields; j++) {
+				len += strlen(safeGet(row[j])) + 1;
+			}
+
+			/*
+			 * allocate string memory, allow for NULL to
+			 * term string
+			 */
+			tmpString = malloc(len + 1);
+			if (tmpString == NULL) {
+				db->log(ISC_LOG_ERROR, "MySQL module unable to "
+						       "allocate "
+						       "memory for temporary "
+						       "string");
+				mysql_free_result(rs);
+				return (ISC_R_FAILURE);
+			}
+
+			strcpy(tmpString, safeGet(row[2]));
+			for (j = 3; j < fields; j++) {
+				strcat(tmpString, " ");
+				strcat(tmpString, safeGet(row[j]));
+			}
+
+			ttl = strtol(safeGet(row[0]), &endp, 10);
+			if (*endp != '\0' || ttl < 0) {
+				db->log(ISC_LOG_ERROR, "MySQL module ttl must "
+						       "be "
+						       "a positive number");
+				free(tmpString);
+				return (ISC_R_FAILURE);
+			}
+
+			result = db->putrr(lookup, safeGet(row[1]), ttl,
+					   tmpString);
+			free(tmpString);
+		}
+
+		if (result != ISC_R_SUCCESS) {
+			mysql_free_result(rs);
+			db->log(ISC_LOG_ERROR, "putrr returned error: %d",
+				result);
+			return (ISC_R_FAILURE);
+		}
+
+		row = mysql_fetch_row(rs);
+	}
+
+	mysql_free_result(rs);
+	return (result);
+}
+
+/*
+ * DLZ methods
+ */
+
+/*% determine if the zone is supported by (in) the database */
+isc_result_t
+dlz_findzonedb(void *dbdata, const char *name, dns_clientinfomethods_t *methods,
+	       dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+	my_ulonglong rows;
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	result = mysql_get_resultset(name, NULL, NULL, FINDZONE, dbdata, &rs);
+	if (result != ISC_R_SUCCESS || rs == NULL) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+
+		db->log(ISC_LOG_ERROR, "MySQL module unable to return "
+				       "result set for findzone query");
+
+		return (ISC_R_FAILURE);
+	}
+
+	/*
+	 * if we returned any rows, the zone is supported.
+	 */
+	rows = mysql_num_rows(rs);
+	mysql_free_result(rs);
+	if (rows > 0) {
+		mysql_get_resultset(name, NULL, NULL, COUNTZONE, dbdata, NULL);
+		return (ISC_R_SUCCESS);
+	}
+
+	return (ISC_R_NOTFOUND);
+}
+
+/*% Determine if the client is allowed to perform a zone transfer */
+isc_result_t
+dlz_allowzonexfr(void *dbdata, const char *name, const char *client) {
+	isc_result_t result;
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+	MYSQL_RES *rs = NULL;
+	my_ulonglong rows;
+
+	/* first check if the zone is supported by the database. */
+	result = dlz_findzonedb(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.
+	 */
+	result = mysql_get_resultset(name, NULL, client, ALLOWXFR, dbdata, &rs);
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+
+	if (result != ISC_R_SUCCESS || rs == NULL) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		db->log(ISC_LOG_ERROR, "MySQL module unable to return "
+				       "result set for allow xfr query");
+		return (ISC_R_FAILURE);
+	}
+
+	/*
+	 * count how many rows in result set; if we returned any,
+	 * zone xfr is allowed.
+	 */
+	rows = mysql_num_rows(rs);
+	mysql_free_result(rs);
+	if (rows > 0) {
+		return (ISC_R_SUCCESS);
+	}
+
+	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.
+ */
+isc_result_t
+dlz_allnodes(const char *zone, void *dbdata, dns_sdlzallnodes_t *allnodes) {
+	isc_result_t result;
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+	MYSQL_RES *rs = NULL;
+	MYSQL_ROW row;
+	unsigned int fields;
+	unsigned int j;
+	char *tmpString;
+	char *endp;
+	int ttl;
+
+	result = mysql_get_resultset(zone, NULL, NULL, ALLNODES, dbdata, &rs);
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+
+	/* if we didn't get a result set, log an err msg. */
+	if (result != ISC_R_SUCCESS) {
+		db->log(ISC_LOG_ERROR, "MySQL module unable to return "
+				       "result set for all nodes query");
+		goto cleanup;
+	}
+
+	result = ISC_R_NOTFOUND;
+
+	fields = mysql_num_fields(rs); /* how many columns in result set */
+	row = mysql_fetch_row(rs);     /* get a row from the result set */
+	while (row != NULL) {
+		if (fields < 4) {
+			db->log(ISC_LOG_ERROR, "MySQL module too few fields "
+					       "returned "
+					       "by all nodes query");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		ttl = strtol(safeGet(row[0]), &endp, 10);
+		if (*endp != '\0' || ttl < 0) {
+			db->log(ISC_LOG_ERROR, "MySQL module ttl must be "
+					       "a positive number");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		if (fields == 4) {
+			result = db->putnamedrr(allnodes, safeGet(row[2]),
+						safeGet(row[1]), ttl,
+						safeGet(row[3]));
+		} else {
+			unsigned int len = 0;
+
+			/*
+			 * more than 4 fields, concatenate the last
+			 * ones together.
+			 */
+			for (j = 3; j < fields; j++) {
+				len += strlen(safeGet(row[j])) + 1;
+			}
+
+			tmpString = malloc(len + 1);
+			if (tmpString == NULL) {
+				db->log(ISC_LOG_ERROR, "MySQL module unable to "
+						       "allocate "
+						       "memory for temporary "
+						       "string");
+				result = ISC_R_FAILURE;
+				goto cleanup;
+			}
+
+			strcpy(tmpString, safeGet(row[3]));
+			for (j = 4; j < fields; j++) {
+				strcat(tmpString, " ");
+				strcat(tmpString, safeGet(row[j]));
+			}
+
+			result = db->putnamedrr(allnodes, safeGet(row[2]),
+						safeGet(row[1]), ttl,
+						tmpString);
+			free(tmpString);
+		}
+
+		if (result != ISC_R_SUCCESS) {
+			db->log(ISC_LOG_ERROR, "putnamedrr returned error: %s",
+				result);
+			result = ISC_R_FAILURE;
+			break;
+		}
+
+		row = mysql_fetch_row(rs);
+	}
+
+cleanup:
+	if (rs != NULL) {
+		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 named.
+ */
+isc_result_t
+dlz_authority(const char *zone, void *dbdata, dns_sdlzlookup_t *lookup) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+
+	result = mysql_get_resultset(zone, NULL, NULL, AUTHORITY, dbdata, &rs);
+	if (result == ISC_R_NOTIMPLEMENTED) {
+		return (result);
+	}
+
+	if (result != ISC_R_SUCCESS) {
+		if (rs != NULL) {
+			mysql_free_result(rs);
+		}
+		db->log(ISC_LOG_ERROR, "MySQL module 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(db, lookup, rs));
+}
+
+/*% If zone is supported, lookup up a (or multiple) record(s) in it */
+isc_result_t
+dlz_lookup(const char *zone, const char *name, void *dbdata,
+	   dns_sdlzlookup_t *lookup, dns_clientinfomethods_t *methods,
+	   dns_clientinfo_t *clientinfo) {
+	isc_result_t result;
+	MYSQL_RES *rs = NULL;
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+
+	UNUSED(methods);
+	UNUSED(clientinfo);
+
+	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);
+		}
+		db->log(ISC_LOG_ERROR, "MySQL module 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(db, lookup, rs));
+}
+
+/*%
+ * Create an instance of the module.
+ */
+isc_result_t
+dlz_create(const char *dlzname, unsigned int argc, char *argv[], void **dbdata,
+	   ...) {
+	isc_result_t result = ISC_R_FAILURE;
+	mysql_instance_t *mysql = NULL;
+	dbinstance_t *dbi = NULL;
+	MYSQL *dbc;
+	char *tmp = NULL;
+	char *endp = NULL;
+	const char *helper_name;
+	int dbcount, i, j;
+	va_list ap;
+
+	UNUSED(dlzname);
+
+	/* allocate memory for MySQL instance */
+	mysql = calloc(1, sizeof(mysql_instance_t));
+	if (mysql == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+	memset(mysql, 0, sizeof(mysql_instance_t));
+
+	/* Fill in the helper functions */
+	va_start(ap, dbdata);
+	while ((helper_name = va_arg(ap, const char *)) != NULL) {
+		b9_add_helper(mysql, helper_name, va_arg(ap, void *));
+	}
+	va_end(ap);
+
+	/* if debugging, let user know we are multithreaded. */
+	mysql->log(ISC_LOG_DEBUG(1), "MySQL module running multithreaded");
+
+	/* verify we have at least 4 arg's passed to the module */
+	if (argc < 4) {
+		mysql->log(ISC_LOG_ERROR, "MySQL module requires "
+					  "at least 4 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* no more than 8 arg's should be passed to the module */
+	if (argc > 8) {
+		mysql->log(ISC_LOG_ERROR, "MySQL module cannot accept "
+					  "more than 7 command line args.");
+		return (ISC_R_FAILURE);
+	}
+
+	/* get db name - required */
+	mysql->dbname = get_parameter_value(argv[1], "dbname=");
+	if (mysql->dbname == NULL) {
+		mysql->log(ISC_LOG_ERROR, "MySQL module requires a dbname "
+					  "parameter.");
+		result = ISC_R_FAILURE;
+		goto cleanup;
+	}
+
+	/* get db port.  Not required, but must be > 0 if specified */
+	tmp = get_parameter_value(argv[1], "port=");
+	if (tmp == NULL) {
+		mysql->port = 0;
+	} else {
+		mysql->port = strtol(tmp, &endp, 10);
+		if (*endp != '\0' || mysql->port < 0) {
+			mysql->log(ISC_LOG_ERROR, "Mysql module: port "
+						  "must be a positive number.");
+			free(tmp);
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		free(tmp);
+	}
+
+	mysql->host = get_parameter_value(argv[1], "host=");
+	mysql->user = get_parameter_value(argv[1], "user=");
+	mysql->pass = get_parameter_value(argv[1], "pass=");
+	mysql->socket = get_parameter_value(argv[1], "socket=");
+
+	mysql->flags = CLIENT_REMEMBER_OPTIONS;
+
+	tmp = get_parameter_value(argv[1], "compress=");
+	if (tmp != NULL) {
+		if (strcasecmp(tmp, "true") == 0) {
+			mysql->flags |= CLIENT_COMPRESS;
+		}
+		free(tmp);
+	}
+
+	tmp = get_parameter_value(argv[1], "ssl=");
+	if (tmp != NULL) {
+		if (strcasecmp(tmp, "true") == 0) {
+			mysql->flags |= CLIENT_SSL;
+		}
+		free(tmp);
+	}
+
+	tmp = get_parameter_value(argv[1], "space=");
+	if (tmp != NULL) {
+		if (strcasecmp(tmp, "ignore") == 0) {
+			mysql->flags |= CLIENT_IGNORE_SPACE;
+		}
+		free(tmp);
+	}
+
+	/* multithreaded build can have multiple DB connections */
+	tmp = get_parameter_value(argv[1], "threads=");
+	if (tmp == NULL) {
+		dbcount = 1;
+	} else {
+		dbcount = strtol(tmp, &endp, 10);
+		if (*endp != '\0' || dbcount < 1) {
+			mysql->log(ISC_LOG_ERROR, "MySQL database connection "
+						  "count "
+						  "must be positive.");
+			free(tmp);
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+		free(tmp);
+	}
+
+	/* allocate memory for database connection list */
+	mysql->db = calloc(1, sizeof(db_list_t));
+	if (mysql->db == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto cleanup;
+	}
+
+	/* initialize DB connection list */
+	DLZ_LIST_INIT(*(mysql->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++) {
+		switch (argc) {
+		case 4:
+			result = build_dbinstance(NULL, NULL, NULL, argv[2],
+						  argv[3], NULL, &dbi,
+						  mysql->log);
+			break;
+		case 5:
+			result = build_dbinstance(NULL, NULL, argv[4], argv[2],
+						  argv[3], NULL, &dbi,
+						  mysql->log);
+			break;
+		case 6:
+			result = build_dbinstance(argv[5], NULL, argv[4],
+						  argv[2], argv[3], NULL, &dbi,
+						  mysql->log);
+			break;
+		case 7:
+			result = build_dbinstance(argv[5], argv[6], argv[4],
+						  argv[2], argv[3], NULL, &dbi,
+						  mysql->log);
+			break;
+		case 8:
+			result = build_dbinstance(argv[5], argv[6], argv[4],
+						  argv[2], argv[3], argv[7],
+						  &dbi, mysql->log);
+			break;
+		default:
+			result = ISC_R_FAILURE;
+		}
+
+		if (result != ISC_R_SUCCESS) {
+			mysql->log(ISC_LOG_ERROR, "MySQL module could not "
+						  "create "
+						  "database instance object.");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		/* when multithreaded, build a list of DBI's */
+		DLZ_LINK_INIT(dbi, link);
+		DLZ_LIST_APPEND(*(mysql->db), dbi, link);
+
+		/* create and set db connection */
+		dbi->dbconn = mysql_init(NULL);
+		if (dbi->dbconn == NULL) {
+			mysql->log(ISC_LOG_ERROR, "MySQL module could not "
+						  "allocate "
+						  "memory for database "
+						  "connection");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		dbc = NULL;
+
+		/* enable automatic reconnection. */
+		if (mysql_options((MYSQL *)dbi->dbconn, MYSQL_OPT_RECONNECT,
+				  &(my_bool){ 1 }) != 0)
+		{
+			mysql->log(ISC_LOG_WARNING, "MySQL module failed to "
+						    "set "
+						    "MYSQL_OPT_RECONNECT "
+						    "option, continuing");
+		}
+
+		for (j = 0; dbc == NULL && j < 4; j++) {
+			dbc = mysql_real_connect(
+				(MYSQL *)dbi->dbconn, mysql->host, mysql->user,
+				mysql->pass, mysql->dbname, mysql->port,
+				mysql->socket, mysql->flags);
+			if (dbc == NULL) {
+				mysql->log(ISC_LOG_ERROR,
+					   "MySQL connection failed: %s",
+					   mysql_error((MYSQL *)dbi->dbconn));
+			}
+		}
+
+		if (dbc == NULL) {
+			mysql->log(ISC_LOG_ERROR, "MySQL module failed to "
+						  "create "
+						  "database connection after 4 "
+						  "attempts");
+			result = ISC_R_FAILURE;
+			goto cleanup;
+		}
+
+		/* set DBI = null for next loop through. */
+		dbi = NULL;
+	}
+
+	*dbdata = mysql;
+
+	return (ISC_R_SUCCESS);
+
+cleanup:
+	dlz_destroy(mysql);
+
+	return (result);
+}
+
+/*%
+ * Destroy the module.
+ */
+void
+dlz_destroy(void *dbdata) {
+	mysql_instance_t *db = (mysql_instance_t *)dbdata;
+
+	/* cleanup the list of DBI's */
+	if (db->db != NULL) {
+		dlz_mysql_destroy_dblist((db_list_t *)(db->db));
+	}
+
+	if (db->dbname != NULL) {
+		free(db->dbname);
+	}
+	if (db->host != NULL) {
+		free(db->host);
+	}
+	if (db->user != NULL) {
+		free(db->user);
+	}
+	if (db->pass != NULL) {
+		free(db->pass);
+	}
+	if (db->socket != NULL) {
+		free(db->socket);
+	}
+}
+
+/*
+ * Return the version of the API
+ */
+int
+dlz_version(unsigned int *flags) {
+	*flags |= (DNS_SDLZFLAG_RELATIVEOWNER | DNS_SDLZFLAG_RELATIVERDATA |
+		   DNS_SDLZFLAG_THREADSAFE);
+	return (DLZ_DLOPEN_VERSION);
+}
+
+/*
+ * Register a helper function from the bind9 dlz_dlopen driver
+ */
+static void
+b9_add_helper(mysql_instance_t *db, const char *helper_name, void *ptr) {
+	if (strcmp(helper_name, "log") == 0) {
+		db->log = (log_t *)ptr;
+	}
+	if (strcmp(helper_name, "putrr") == 0) {
+		db->putrr = (dns_sdlz_putrr_t *)ptr;
+	}
+	if (strcmp(helper_name, "putnamedrr") == 0) {
+		db->putnamedrr = (dns_sdlz_putnamedrr_t *)ptr;
+	}
+	if (strcmp(helper_name, "writeable_zone") == 0) {
+		db->writeable_zone = (dns_dlz_writeablezone_t *)ptr;
+	}
+}
diff --git a/contrib/dlz/modules/mysql/testing/README b/contrib/dlz/modules/mysql/testing/README
new file mode 100644
index 0000000..a4b87bb
--- /dev/null
+++ b/contrib/dlz/modules/mysql/testing/README
@@ -0,0 +1,7 @@
+These files were used for testing on Ubuntu Linux using MySQL
+
+- Install MySQL: sudo apt-get install mysql-server
+- Run "mysql --user=USER --password=PASSWORD < dlz.schema" to set up database
+- Run "mysql --user=USER --password=PASSWORD < dlz.data" to populate it
+- update named.conf with correct USER and PASSWORD
+
diff --git a/contrib/dlz/modules/mysql/testing/dlz.data b/contrib/dlz/modules/mysql/testing/dlz.data
new file mode 100644
index 0000000..cef3e13
--- /dev/null
+++ b/contrib/dlz/modules/mysql/testing/dlz.data
@@ -0,0 +1,12 @@
+use BindDB;
+INSERT INTO `records` (`id`, `zone`, `ttl`, `type`, `host`, `mx_priority`, `data`, `primary_ns`, `resp_contact`, `serial`, `refresh`, `retry`, `expire`, `minimum`) VALUES
+(1, 'example.com', 86400, 'SOA', '@', NULL, NULL, 'ns1.example.com.', 'info.example.com.', 2011043001, 10800, 7200, 604800, 86400),
+(2, 'example.com', 86400, 'NS', '@', NULL, 'ns1.example.com.', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(3, 'example.com', 86400, 'NS', '@', NULL, 'ns2.example.com.', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(4, 'example.com', 86400, 'MX', '@', 10, 'mail.example.com.', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(5, 'example.com', 86400, 'A', '@', NULL, '192.168.0.2', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(6, 'example.com', 86400, 'CNAME', 'www', NULL, '@', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(7, 'example.com', 86400, 'A', 'ns1', NULL, '192.168.0.111', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(8, 'example.com', 86400, 'A', 'ns2', NULL, '192.168.0.222', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(9, 'example.com', 86400, 'A', 'mail', NULL, '192.168.0.3', NULL, NULL, NULL, NULL, NULL, NULL, NULL),
+(10, 'example.com', 86400, 'TXT', '@', NULL, 'v=spf1 ip:192.168.0.3 ~all', NULL, NULL, NULL, NULL, NULL, NULL, NULL)
diff --git a/contrib/dlz/modules/mysql/testing/dlz.schema b/contrib/dlz/modules/mysql/testing/dlz.schema
new file mode 100644
index 0000000..f20b59e
--- /dev/null
+++ b/contrib/dlz/modules/mysql/testing/dlz.schema
@@ -0,0 +1,30 @@
+CREATE DATABASE `BindDB` DEFAULT CHARACTER SET latin1;
+USE `BindDB`;
+
+CREATE TABLE IF NOT EXISTS `records` (
+    `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
+    `zone` varchar(255) NOT NULL,
+    `ttl` int(11) NOT NULL DEFAULT '86400',
+    `type` varchar(255) NOT NULL,
+    `host` varchar(255) NOT NULL DEFAULT '@',
+    `mx_priority` int(11) DEFAULT NULL,
+    `data` text,
+    `primary_ns` varchar(255) DEFAULT NULL,
+    `resp_contact` varchar(255) DEFAULT NULL,
+    `serial` bigint(20) DEFAULT NULL,
+    `refresh` int(11) DEFAULT NULL,
+    `retry` int(11) DEFAULT NULL,
+    `expire` int(11) DEFAULT NULL,
+    `minimum` int(11) DEFAULT NULL,
+    PRIMARY KEY (`id`),
+    KEY `type` (`type`),
+    KEY `host` (`host`),
+    KEY `zone` (`zone`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+
+CREATE TABLE IF NOT EXISTS `xfr` (
+    `zone` varchar(255) NOT NULL,
+    `client` varchar(255) NOT NULL,
+    KEY `zone` (`zone`),
+    KEY `client` (`client`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
diff --git a/contrib/dlz/modules/mysql/testing/named.conf b/contrib/dlz/modules/mysql/testing/named.conf
new file mode 100644
index 0000000..1152143
--- /dev/null
+++ b/contrib/dlz/modules/mysql/testing/named.conf
@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+controls { };
+
+options {
+	directory ".";
+	port 5300;
+	pid-file "named.pid";
+	session-keyfile "session.key";
+	listen-on { any; };
+	listen-on-v6 { none; };
+	recursion no;
+};
+
+key rndc_key {
+	secret "1234abcd8765";
+	algorithm hmac-md5;
+};
+
+controls {
+	inet 127.0.0.1 port 9953 allow { any; } keys { rndc_key; };
+};
+
+dlz "test" {
+	database "dlopen ../dlz_mysql_dynamic.so
+           {
+             host=127.0.0.1 port=3306 socket=/tmp/mysql.sock
+             dbname=BindDB user=USER pass=PASSWORD threads=2
+           }
+           {SELECT zone FROM records WHERE zone = '$zone$'}
+           {SELECT ttl, type, mx_priority, IF(type = 'TXT', CONCAT('\"',data,'\"'), data) AS data FROM records WHERE zone = '$zone$' AND host = '$record$' AND type <> 'SOA' AND type <> 'NS'}
+           {SELECT ttl, type, data, primary_ns, resp_contact, serial, refresh, retry, expire, minimum FROM records WHERE zone = '$zone$' AND (type = 'SOA' OR type='NS')}
+           {SELECT ttl, type, host, mx_priority, IF(type = 'TXT', CONCAT('\"',data,'\"'), data) AS data, resp_contact, serial, refresh, retry, expire, minimum FROM records WHERE zone = '$zone$' AND type <> 'SOA' AND type <> 'NS'}
+           {SELECT zone FROM xfr where zone='$zone$' AND client = '$client$'}";
+};