dlz_mysql_driver.c

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	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);
	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 postive 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(ns_g_mctx, len + 1);
			if (tmpString == NULL) {	/* we need more ram. */
				isc_log_write(dns_lctx,
					      DNS_LOGCATEGORY_DATABASE,
					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
					      "mysql driver unable "
					      "to allocate memory for "
					      "temporary string");
				mysql_free_result(rs);
				return (ISC_R_FAILURE);
			}
			/* copy this field to tmpString */
			strcpy(tmpString, safeGet(row[3]));
			/* concatonate 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(ns_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)
{
	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, 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 paramters. */

	/* 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(ns_g_mctx, tmp);
			result = ISC_R_FAILURE;
			goto full_cleanup;
		}
		isc_mem_free(ns_g_mctx, tmp);
	}

	/* how many queries were passed in from config file? */
	switch(argc) {
	case 4:
		result = build_sqldbinstance(ns_g_mctx, NULL, NULL, NULL,
					     argv[2], argv[3], NULL, &dbi);
		break;
	case 5:
		result = build_sqldbinstance(ns_g_mctx, NULL, NULL, argv[4],
					     argv[2], argv[3], NULL, &dbi);
		break;
	case 6:
		result = build_sqldbinstance(ns_g_mctx, argv[5], NULL, argv[4],
					     argv[2], argv[3], NULL, &dbi);
		break;
	case 7:
		result = build_sqldbinstance(ns_g_mctx, argv[5],
					     argv[6], argv[4],
					     argv[2], argv[3], NULL, &dbi);
		break;
	case 8:
		result = build_sqldbinstance(ns_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 full_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(ns_g_mctx, tmp);
	}

	tmp = getParameterValue(argv[1], "ssl=");
	if (tmp != NULL) {
		if (strcasecmp(tmp, "true") == 0)
			flags = flags | CLIENT_SSL;
		isc_mem_free(ns_g_mctx, tmp);
	}

	tmp = getParameterValue(argv[1], "space=");
	if (tmp != NULL) {
		if (strcasecmp(tmp, "ignore") == 0)
			flags = flags | CLIENT_IGNORE_SPACE;
		isc_mem_free(ns_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=");

	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:

	destroy_sqldbinstance(dbi);

 cleanup:

	if (dbname != NULL)
		isc_mem_free(ns_g_mctx, dbname);
	if (host != NULL)
		isc_mem_free(ns_g_mctx, host);
	if (user != NULL)
		isc_mem_free(ns_g_mctx, user);
	if (pass != NULL)
		isc_mem_free(ns_g_mctx, pass);
	if (socket != NULL)
		isc_mem_free(ns_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
};

/*%
 * 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,
				  ns_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