func_odbc.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (c) 2005, 2006 Tilghman Lesher
 * Copyright (c) 2008, 2009 Digium, Inc.
 *
 * Tilghman Lesher <func_odbc__200508@the-tilghman.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 *
 * \brief ODBC lookups
 *
 * \author Tilghman Lesher <func_odbc__200508@the-tilghman.com>
 *
 * \ingroup functions
 */

/*** MODULEINFO
	<depend>res_odbc</depend>
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/module.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/config.h"
#include "asterisk/res_odbc.h"
#include "asterisk/res_odbc_transaction.h"
#include "asterisk/app.h"
#include "asterisk/cli.h"
#include "asterisk/strings.h"

/*** DOCUMENTATION
	<function name="ODBC_FETCH" language="en_US">
		<synopsis>
			Fetch a row from a multirow query.
		</synopsis>
		<syntax>
			<parameter name="result-id" required="true" />
		</syntax>
		<description>
			<para>For queries which are marked as mode=multirow, the original 
			query returns a <replaceable>result-id</replaceable> from which results 
			may be fetched.  This function implements the actual fetch of the results.</para>
			<para>This also sets <variable>ODBC_FETCH_STATUS</variable>.</para>
			<variablelist>
				<variable name="ODBC_FETCH_STATUS">
					<value name="SUCESS">
						If rows are available.
					</value>
					<value name="FAILURE">
						If no rows are available.
					</value>
				</variable>
			</variablelist>
		</description>
	</function>
	<application name="ODBCFinish" language="en_US">
		<synopsis>
			Clear the resultset of a sucessful multirow query.
		</synopsis>
		<syntax>
			<parameter name="result-id" required="true" />
		</syntax>
		<description>
			<para>For queries which are marked as mode=multirow, this will clear 
			any remaining rows of the specified resultset.</para>
		</description>
	</application>
	<function name="SQL_ESC" language="en_US">
		<synopsis>
			Escapes single ticks for use in SQL statements.
		</synopsis>
		<syntax>
			<parameter name="string" required="true" />
		</syntax>
		<description>
			<para>Used in SQL templates to escape data which may contain single ticks 
			<literal>'</literal> which are otherwise used to delimit data.</para>
			<para>Example: SELECT foo FROM bar WHERE baz='${SQL_ESC(${ARG1})}'</para>
		</description>
	</function>
 ***/

static char *config = "func_odbc.conf";

#define DEFAULT_SINGLE_DB_CONNECTION 0

static int single_db_connection;

AST_RWLOCK_DEFINE_STATIC(single_db_connection_lock);

enum odbc_option_flags {
	OPT_ESCAPECOMMAS =	(1 << 0),
	OPT_MULTIROW     =	(1 << 1),
};

struct acf_odbc_query {
	AST_RWLIST_ENTRY(acf_odbc_query) list;
	char readhandle[5][30];
	char writehandle[5][30];
	char *sql_read;
	char *sql_write;
	char *sql_insert;
	unsigned int flags;
	int rowlimit;
	struct ast_custom_function *acf;
};

static void odbc_datastore_free(void *data);

static const struct ast_datastore_info odbc_info = {
	.type = "FUNC_ODBC",
	.destroy = odbc_datastore_free,
};

/* For storing each result row */
struct odbc_datastore_row {
	AST_LIST_ENTRY(odbc_datastore_row) list;
	char data[0];
};

/* For storing each result set */
struct odbc_datastore {
	AST_LIST_HEAD(, odbc_datastore_row);
	char names[0];
};

/* \brief Data source name
 *
 * This holds data that pertains to a DSN
 */
struct dsn {
	/*! A connection to the database */
	struct odbc_obj *connection;
	/*! The name of the DSN as defined in res_odbc.conf */
	char name[0];
};

#define DSN_BUCKETS 37

struct ao2_container *dsns;

static int dsn_hash(const void *obj, const int flags)
{
	const struct dsn *object;
	const char *key;

	switch (flags & OBJ_SEARCH_MASK) {
	case OBJ_SEARCH_KEY:
		key = obj;
		break;
	case OBJ_SEARCH_OBJECT:
		object = obj;
		key = object->name;
		break;
	default:
		ast_assert(0);
		return 0;
	}
	return ast_str_hash(key);
}

static int dsn_cmp(void *obj, void *arg, int flags)
{
	const struct dsn *object_left = obj;
	const struct dsn *object_right = arg;
	const char *right_key = arg;
	int cmp;

	switch (flags & OBJ_SEARCH_MASK) {
	case OBJ_SEARCH_OBJECT:
		right_key = object_right->name;
		/* Fall through */
	case OBJ_SEARCH_KEY:
		cmp = strcmp(object_left->name, right_key);
		break;
	case OBJ_SEARCH_PARTIAL_KEY:
		cmp = strncmp(object_left->name, right_key, strlen(right_key));
		break;
	default:
		cmp = 0;
		break;
	}

	if (cmp) {
		return 0;
	}

	return CMP_MATCH;
}

static void dsn_destructor(void *obj)
{
	struct dsn *dsn = obj;

	if (dsn->connection) {
		ast_odbc_release_obj(dsn->connection);
	}
}

/*!
 * \brief Create a DSN and connect to the database
 *
 * \param name The name of the DSN as found in res_odbc.conf
 * \retval NULL Fail
 * \retval non-NULL The newly-created structure
 */
static struct dsn *create_dsn(const char *name)
{
	struct dsn *dsn;

	if (!dsns) {
		return NULL;
	}

	dsn = ao2_alloc(sizeof(*dsn) + strlen(name) + 1, dsn_destructor);
	if (!dsn) {
		return NULL;
	}

	/* Safe */
	strcpy(dsn->name, name);

	dsn->connection = ast_odbc_request_obj(name, 0);
	if (!dsn->connection) {
		ao2_ref(dsn, -1);
		return NULL;
	}

	if (!ao2_link_flags(dsns, dsn, OBJ_NOLOCK)) {
		ao2_ref(dsn, -1);
		return NULL;
	}

	return dsn;
}

static SQLHSTMT silent_execute(struct odbc_obj *obj, void *data);

/*!
 * \brief Determine if the connection has died.
 *
 * \param connection The connection to check
 * \retval 1 Yep, it's dead
 * \retval 0 It's alive and well
 */
static int connection_dead(struct odbc_obj *connection)
{
	SQLINTEGER dead;
	SQLRETURN res;
	SQLHSTMT stmt;

	if (!connection) {
		return 1;
	}

	res = SQLGetConnectAttr(connection->con, SQL_ATTR_CONNECTION_DEAD, &dead, 0, 0);
	if (SQL_SUCCEEDED(res)) {
		return dead == SQL_CD_TRUE ? 1 : 0;
	}

	/* If the Driver doesn't support SQL_ATTR_CONNECTION_DEAD do a direct
	 * execute of a probing statement and see if that succeeds instead
	 */
	stmt = ast_odbc_direct_execute(connection, silent_execute, "SELECT 1");
	if (!stmt) {
		return 1;
	}

	SQLFreeHandle(SQL_HANDLE_STMT, stmt);
	return 0;
}

/*!
 * \brief Retrieve a DSN, or create it if it does not exist.
 *
 * The created DSN is returned locked. This should be inconsequential
 * to callers in most cases.
 *
 * When finished with the returned structure, the caller must call
 * \ref release_dsn
 *
 * \param name Name of the DSN as found in res_odbc.conf
 * \retval NULL Unable to retrieve or create the DSN
 * \retval non-NULL The retrieved/created locked DSN
 */
static struct dsn *get_dsn(const char *name)
{
	struct dsn *dsn;

	if (!dsns) {
		return NULL;
	}

	ao2_lock(dsns);
	dsn = ao2_find(dsns, name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
	if (!dsn) {
		dsn = create_dsn(name);
	}
	ao2_unlock(dsns);

	if (!dsn) {
		return NULL;
	}

	ao2_lock(dsn);
	if (!dsn->connection) {
		dsn->connection = ast_odbc_request_obj(name, 0);
		if (!dsn->connection) {
			ao2_unlock(dsn);
			ao2_ref(dsn, -1);
			return NULL;
		}
		return dsn;
	}

	if (connection_dead(dsn->connection)) {
		ast_odbc_release_obj(dsn->connection);
		dsn->connection = ast_odbc_request_obj(name, 0);
		if (!dsn->connection) {
			ao2_unlock(dsn);
			ao2_ref(dsn, -1);
			return NULL;
		}
	}

	return dsn;
}

/*!
 * \brief Get a DB handle via a DSN or directly
 *
 * If single db connection then get the DB handle via DSN
 * else by requesting a connection directly
 *
 * \param dsn_name Name of the DSN as found in res_odbc.conf
 * \param dsn The pointer to the DSN
 * \retval NULL Unable to retrieve the DB handle
 * \retval non-NULL The retrieved DB handle
 */
static struct odbc_obj *get_odbc_obj(const char *dsn_name, struct dsn **dsn)
{
	struct odbc_obj *obj = NULL;

	ast_rwlock_rdlock(&single_db_connection_lock);
	if (single_db_connection) {
		if (dsn) {
			*dsn = get_dsn(dsn_name);
			if (*dsn) {
				obj = (*dsn)->connection;
			}
		}
	} else {
		obj = ast_odbc_request_obj(dsn_name, 0);
	}
	ast_rwlock_unlock(&single_db_connection_lock);

	return obj;
}

/*!
 * \brief Release an ODBC obj or a DSN
 *
 * If single db connection then unlock and unreference the DSN
 * else release the ODBC obj
 *
 * \param obj The pointer to the ODBC obj to release
 * \param dsn The pointer to the dsn to unlock and unreference
 */
static inline void release_obj_or_dsn(struct odbc_obj **obj, struct dsn **dsn)
{
	if (dsn && *dsn) {
		/* If multiple connections are not enabled then the guarantee
		 * of a single connection already exists and holding on to the
		 * connection would prevent any other user from acquiring it
		 * indefinitely.
		 */
		if (ast_odbc_get_max_connections((*dsn)->name) < 2) {
			ast_odbc_release_obj((*dsn)->connection);
			(*dsn)->connection = NULL;
		}
		ao2_unlock(*dsn);
		ao2_ref(*dsn, -1);
		*dsn = NULL;
		/* Some callers may provide both an obj and dsn. To ensure that
		 * the connection is not released twice we set it to NULL here if
		 * present.
		 */
		if (obj) {
			*obj = NULL;
		}
	} else if (obj && *obj) {
		ast_odbc_release_obj(*obj);
		*obj = NULL;
	}
}

static AST_RWLIST_HEAD_STATIC(queries, acf_odbc_query);

static int resultcount = 0;

AST_THREADSTORAGE(sql_buf);
AST_THREADSTORAGE(sql2_buf);
AST_THREADSTORAGE(coldata_buf);
AST_THREADSTORAGE(colnames_buf);

static int acf_fetch(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len);

static void odbc_datastore_free(void *data)
{
	struct odbc_datastore *result = data;
	struct odbc_datastore_row *row;

	if (!result) {
		return;
	}

	AST_LIST_LOCK(result);
	while ((row = AST_LIST_REMOVE_HEAD(result, list))) {
		ast_free(row);
	}
	AST_LIST_UNLOCK(result);
	AST_LIST_HEAD_DESTROY(result);
	ast_free(result);
}

/*!
 * \brief Common execution function for SQL queries.
 *
 * \param obj DB connection
 * \param data The query to execute
 * \param silent If true, do not print warnings on failure
 * \retval NULL Failed to execute query
 * \retval non-NULL The executed statement
 */
static SQLHSTMT execute(struct odbc_obj *obj, void *data, int silent)
{
	int res;
	char *sql = data;
	SQLHSTMT stmt;

	res = SQLAllocHandle (SQL_HANDLE_STMT, obj->con, &stmt);
	if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) {
		ast_log(LOG_WARNING, "SQL Alloc Handle failed (%d)!\n", res);
		return NULL;
	}

	res = SQLExecDirect(stmt, (unsigned char *)sql, SQL_NTS);
	if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO) && (res != SQL_NO_DATA)) {
		if (res == SQL_ERROR && !silent) {
			int i;
			SQLINTEGER nativeerror=0, numfields=0;
			SQLSMALLINT diagbytes=0;
			unsigned char state[10], diagnostic[256];

			SQLGetDiagField(SQL_HANDLE_STMT, stmt, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
			for (i = 0; i < numfields; i++) {
				SQLGetDiagRec(SQL_HANDLE_STMT, stmt, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
				ast_log(LOG_WARNING, "SQL Execute returned an error %d: %s: %s (%d)\n", res, state, diagnostic, diagbytes);
				if (i > 10) {
					ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
					break;
				}
			}
		}

		if (!silent) {
			ast_log(LOG_WARNING, "SQL Exec Direct failed (%d)![%s]\n", res, sql);
		}
		SQLCloseCursor(stmt);
		SQLFreeHandle(SQL_HANDLE_STMT, stmt);
		return NULL;
	}

	return stmt;
}

static SQLHSTMT generic_execute(struct odbc_obj *obj, void *data)
{
	return execute(obj, data, 0);
}

static SQLHSTMT silent_execute(struct odbc_obj *obj, void *data)
{
	return execute(obj, data, 1);
}

/*
 * Master control routine
 */
static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, const char *value)
{
	struct odbc_obj *obj = NULL;
	struct acf_odbc_query *query;
	char *t, varname[15];
	int i, dsn_num, bogus_chan = 0;
	int transactional = 0;
	AST_DECLARE_APP_ARGS(values,
		AST_APP_ARG(field)[100];
	);
	AST_DECLARE_APP_ARGS(args,
		AST_APP_ARG(field)[100];
	);
	SQLHSTMT stmt = NULL;
	SQLLEN rows=0;
	struct ast_str *buf = ast_str_thread_get(&sql_buf, 16);
	struct ast_str *insertbuf = ast_str_thread_get(&sql2_buf, 16);
	const char *status = "FAILURE";
	struct dsn *dsn = NULL;

	if (!buf || !insertbuf) {
		return -1;
	}

	AST_RWLIST_RDLOCK(&queries);
	AST_RWLIST_TRAVERSE(&queries, query, list) {
		if (!strcmp(query->acf->name, cmd)) {
			break;
		}
	}

	if (!query) {
		ast_log(LOG_ERROR, "No such function '%s'\n", cmd);
		AST_RWLIST_UNLOCK(&queries);
		if (chan) {
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
		}
		return -1;
	}

	if (!chan) {
		if (!(chan = ast_dummy_channel_alloc())) {
			AST_RWLIST_UNLOCK(&queries);
			return -1;
		}
		bogus_chan = 1;
	}

	if (!bogus_chan) {
		ast_autoservice_start(chan);
	}

	ast_str_make_space(&buf, strlen(query->sql_write) * 2 + 300);
	/* We only get here if sql_write is set. sql_insert is optional however. */
	if (query->sql_insert) {
		ast_str_make_space(&insertbuf, strlen(query->sql_insert) * 2 + 300);
	}

	/* Parse our arguments */
	t = value ? ast_strdupa(value) : "";

	if (!s || !t) {
		ast_log(LOG_ERROR, "Out of memory\n");
		AST_RWLIST_UNLOCK(&queries);
		if (!bogus_chan) {
			ast_autoservice_stop(chan);
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
		} else {
			ast_channel_unref(chan);
		}
		return -1;
	}

	AST_STANDARD_APP_ARGS(args, s);
	for (i = 0; i < args.argc; i++) {
		snprintf(varname, sizeof(varname), "ARG%d", i + 1);
		pbx_builtin_pushvar_helper(chan, varname, args.field[i]);
	}

	/* Parse values, just like arguments */
	AST_STANDARD_APP_ARGS(values, t);
	for (i = 0; i < values.argc; i++) {
		snprintf(varname, sizeof(varname), "VAL%d", i + 1);
		pbx_builtin_pushvar_helper(chan, varname, values.field[i]);
	}

	/* Additionally set the value as a whole (but push an empty string if value is NULL) */
	pbx_builtin_pushvar_helper(chan, "VALUE", value ? value : "");

	ast_str_substitute_variables(&buf, 0, chan, query->sql_write);
	if (query->sql_insert) {
		ast_str_substitute_variables(&insertbuf, 0, chan, query->sql_insert);
	}

	if (bogus_chan) {
		chan = ast_channel_unref(chan);
	} else {
		/* Restore prior values */
		for (i = 0; i < args.argc; i++) {
			snprintf(varname, sizeof(varname), "ARG%d", i + 1);
			pbx_builtin_setvar_helper(chan, varname, NULL);
		}

		for (i = 0; i < values.argc; i++) {
			snprintf(varname, sizeof(varname), "VAL%d", i + 1);
			pbx_builtin_setvar_helper(chan, varname, NULL);
		}
		pbx_builtin_setvar_helper(chan, "VALUE", NULL);
	}

	/*!\note
	 * Okay, this part is confusing.  Transactions belong to a single database
	 * handle.  Therefore, when working with transactions, we CANNOT failover
	 * to multiple DSNs.  We MUST have a single handle all the way through the
	 * transaction, or else we CANNOT enforce atomicity.
	 */
	for (dsn_num = 0; dsn_num < 5; dsn_num++) {
		if (!ast_strlen_zero(query->writehandle[dsn_num])) {
			if (transactional) {
				/* This can only happen second time through or greater. */
				ast_log(LOG_WARNING, "Transactions do not work well with multiple DSNs for 'writehandle'\n");
			}

			if ((obj = ast_odbc_retrieve_transaction_obj(chan, query->writehandle[dsn_num]))) {
				transactional = 1;
			} else {
				obj = get_odbc_obj(query->writehandle[dsn_num], &dsn);
				transactional = 0;
			}

			if (obj && (stmt = ast_odbc_direct_execute(obj, generic_execute, ast_str_buffer(buf)))) {
				break;
			}
			if (!transactional) {
				release_obj_or_dsn (&obj, &dsn);
			}
		}
	}

	if (stmt) {
		SQLRowCount(stmt, &rows);
		SQLCloseCursor(stmt);
		SQLFreeHandle(SQL_HANDLE_STMT, stmt);

		if (rows != 0) {
			status = "SUCCESS";

		} else if (query->sql_insert) {
			if (!transactional) {
				release_obj_or_dsn (&obj, &dsn);
			}

			for (transactional = 0, dsn_num = 0; dsn_num < 5; dsn_num++) {
				if (!ast_strlen_zero(query->writehandle[dsn_num])) {
					if (transactional) {
						/* This can only happen second time through or greater. */
						ast_log(LOG_WARNING, "Transactions do not work well with multiple DSNs for 'writehandle'\n");
					} else {
						release_obj_or_dsn (&obj, &dsn);
					}

					if ((obj = ast_odbc_retrieve_transaction_obj(chan, query->writehandle[dsn_num]))) {
						transactional = 1;
					} else {
						obj = get_odbc_obj(query->writehandle[dsn_num], &dsn);
						transactional = 0;
					}
					if (obj) {
						stmt = ast_odbc_direct_execute(obj, generic_execute, ast_str_buffer(insertbuf));
					}
				}
				if (stmt) {
					status = "FAILOVER";
					SQLRowCount(stmt, &rows);
					SQLCloseCursor(stmt);
					SQLFreeHandle(SQL_HANDLE_STMT, stmt);
					break;
				}
			}
		}
	}

	AST_RWLIST_UNLOCK(&queries);

	/* Output the affected rows, for all cases.  In the event of failure, we
	 * flag this as -1 rows.  Note that this is different from 0 affected rows
	 * which would be the case if we succeeded in our query, but the values did
	 * not change. */
	if (!bogus_chan) {
		snprintf(varname, sizeof(varname), "%d", (int)rows);
		pbx_builtin_setvar_helper(chan, "ODBCROWS", varname);
		pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
	}

	if (!transactional) {
		release_obj_or_dsn (&obj, &dsn);
	}

	if (!bogus_chan) {
		ast_autoservice_stop(chan);
	}

	return 0;
}

static int acf_odbc_read(struct ast_channel *chan, const char *cmd, char *s, char *buf, size_t len)
{
	struct odbc_obj *obj = NULL;
	struct acf_odbc_query *query;
	char varname[15], rowcount[12] = "-1";
	struct ast_str *colnames = ast_str_thread_get(&colnames_buf, 16);
	int res, x, y, buflen = 0, escapecommas, rowlimit = 1, multirow = 0, dsn_num, bogus_chan = 0;
	AST_DECLARE_APP_ARGS(args,
		AST_APP_ARG(field)[100];
	);
	SQLHSTMT stmt = NULL;
	SQLSMALLINT colcount=0;
	SQLLEN indicator;
	SQLSMALLINT collength;
	struct odbc_datastore *resultset = NULL;
	struct odbc_datastore_row *row = NULL;
	struct ast_str *sql = ast_str_thread_get(&sql_buf, 16);
	const char *status = "FAILURE";
	struct dsn *dsn = NULL;

	if (!sql || !colnames) {
		if (chan) {
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
		}
		return -1;
	}

	ast_str_reset(colnames);

	AST_RWLIST_RDLOCK(&queries);
	AST_RWLIST_TRAVERSE(&queries, query, list) {
		if (!strcmp(query->acf->name, cmd)) {
			break;
		}
	}

	if (!query) {
		ast_log(LOG_ERROR, "No such function '%s'\n", cmd);
		AST_RWLIST_UNLOCK(&queries);
		if (chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
		}
		return -1;
	}

	if (!chan) {
		if (!(chan = ast_dummy_channel_alloc())) {
			AST_RWLIST_UNLOCK(&queries);
			return -1;
		}
		bogus_chan = 1;
	}

	if (!bogus_chan) {
		ast_autoservice_start(chan);
	}

	AST_STANDARD_APP_ARGS(args, s);
	for (x = 0; x < args.argc; x++) {
		snprintf(varname, sizeof(varname), "ARG%d", x + 1);
		pbx_builtin_pushvar_helper(chan, varname, args.field[x]);
	}

	ast_str_substitute_variables(&sql, 0, chan, query->sql_read);

	if (bogus_chan) {
		chan = ast_channel_unref(chan);
	} else {
		/* Restore prior values */
		for (x = 0; x < args.argc; x++) {
			snprintf(varname, sizeof(varname), "ARG%d", x + 1);
			pbx_builtin_setvar_helper(chan, varname, NULL);
		}
	}

	/* Save these flags, so we can release the lock */
	escapecommas = ast_test_flag(query, OPT_ESCAPECOMMAS);
	if (!bogus_chan && ast_test_flag(query, OPT_MULTIROW)) {
		if (!(resultset = ast_calloc(1, sizeof(*resultset)))) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
			ast_autoservice_stop(chan);
			return -1;
		}
		AST_LIST_HEAD_INIT(resultset);
		if (query->rowlimit) {
			rowlimit = query->rowlimit;
		} else {
			rowlimit = INT_MAX;
		}
		multirow = 1;
	} else if (!bogus_chan) {
		if (query->rowlimit > 1) {
			rowlimit = query->rowlimit;
			if (!(resultset = ast_calloc(1, sizeof(*resultset)))) {
				pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
				pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
				ast_autoservice_stop(chan);
				return -1;
			}
			AST_LIST_HEAD_INIT(resultset);
		}
	}
	AST_RWLIST_UNLOCK(&queries);

	for (dsn_num = 0; dsn_num < 5; dsn_num++) {
		if (!ast_strlen_zero(query->readhandle[dsn_num])) {
			obj = get_odbc_obj(query->readhandle[dsn_num], &dsn);
			if (!obj) {
				continue;
			}
			stmt = ast_odbc_direct_execute(obj, generic_execute, ast_str_buffer(sql));
		}
		if (stmt) {
			break;
		}
		release_obj_or_dsn (&obj, &dsn);
	}

	if (!stmt) {
		ast_log(LOG_ERROR, "Unable to execute query [%s]\n", ast_str_buffer(sql));
		release_obj_or_dsn (&obj, &dsn);
		if (!bogus_chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			ast_autoservice_stop(chan);
		}
		odbc_datastore_free(resultset);
		return -1;
	}

	res = SQLNumResultCols(stmt, &colcount);
	if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) {
		ast_log(LOG_WARNING, "SQL Column Count error!\n[%s]\n\n", ast_str_buffer(sql));
		SQLCloseCursor(stmt);
		SQLFreeHandle (SQL_HANDLE_STMT, stmt);
		release_obj_or_dsn (&obj, &dsn);
		if (!bogus_chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			ast_autoservice_stop(chan);
		}
		odbc_datastore_free(resultset);
		return -1;
	}

	res = SQLFetch(stmt);
	if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) {
		int res1 = -1;
		if (res == SQL_NO_DATA) {
			ast_verb(4, "Found no rows [%s]\n", ast_str_buffer(sql));
			res1 = 0;
			buf[0] = '\0';
			ast_copy_string(rowcount, "0", sizeof(rowcount));
			status = "NODATA";
		} else {
			ast_log(LOG_WARNING, "Error %d in FETCH [%s]\n", res, ast_str_buffer(sql));
			status = "FETCHERROR";
		}
		SQLCloseCursor(stmt);
		SQLFreeHandle(SQL_HANDLE_STMT, stmt);
		release_obj_or_dsn (&obj, &dsn);
		if (!bogus_chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
			ast_autoservice_stop(chan);
		}
		odbc_datastore_free(resultset);
		return res1;
	}

	status = "SUCCESS";

	for (y = 0; y < rowlimit; y++) {
		buf[0] = '\0';
		for (x = 0; x < colcount; x++) {
			int i;
			struct ast_str *coldata = ast_str_thread_get(&coldata_buf, 16);
			char *ptrcoldata;

			if (!coldata) {
				odbc_datastore_free(resultset);
				SQLCloseCursor(stmt);
				SQLFreeHandle(SQL_HANDLE_STMT, stmt);
				release_obj_or_dsn (&obj, &dsn);
				if (!bogus_chan) {
					pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
					ast_autoservice_stop(chan);
				}
				return -1;
			}

			if (y == 0) {
				char colname[256];
				SQLULEN maxcol = 0;

				res = SQLDescribeCol(stmt, x + 1, (unsigned char *)colname, sizeof(colname), &collength, NULL, &maxcol, NULL, NULL);
				ast_debug(3, "Got collength of %d and maxcol of %d for column '%s' (offset %d)\n", (int)collength, (int)maxcol, colname, x);
				if (((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) || collength == 0) {
					snprintf(colname, sizeof(colname), "field%d", x);
				}

				ast_str_make_space(&coldata, maxcol + 1);

				if (ast_str_strlen(colnames)) {
					ast_str_append(&colnames, 0, ",");
				}
				ast_str_append_escapecommas(&colnames, 0, colname, sizeof(colname));

				if (resultset) {
					void *tmp = ast_realloc(resultset, sizeof(*resultset) + ast_str_strlen(colnames) + 1);
					if (!tmp) {
						ast_log(LOG_ERROR, "No space for a new resultset?\n");
						odbc_datastore_free(resultset);
						SQLCloseCursor(stmt);
						SQLFreeHandle(SQL_HANDLE_STMT, stmt);
						release_obj_or_dsn (&obj, &dsn);
						if (!bogus_chan) {
							pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
							pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
							ast_autoservice_stop(chan);
						}
						return -1;
					}
					resultset = tmp;
					strcpy((char *)resultset + sizeof(*resultset), ast_str_buffer(colnames));
				}
			}

			buflen = strlen(buf);
			res = ast_odbc_ast_str_SQLGetData(&coldata, -1, stmt, x + 1, SQL_CHAR, &indicator);
			if (indicator == SQL_NULL_DATA) {
				ast_debug(3, "Got NULL data\n");
				ast_str_reset(coldata);
				res = SQL_SUCCESS;
			}

			if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) {
				ast_log(LOG_WARNING, "SQL Get Data error!\n[%s]\n\n", ast_str_buffer(sql));
				y = -1;
				buf[0] = '\0';
				goto end_acf_read;
			}

			ast_debug(2, "Got coldata of '%s'\n", ast_str_buffer(coldata));

			if (x) {
				buf[buflen++] = ',';
			}

			/* Copy data, encoding '\' and ',' for the argument parser */
			ptrcoldata = ast_str_buffer(coldata);
			for (i = 0; i < ast_str_strlen(coldata); i++) {
				if (escapecommas && (ptrcoldata[i] == '\\' || ptrcoldata[i] == ',')) {
					buf[buflen++] = '\\';
				}
				buf[buflen++] = ptrcoldata[i];

				if (buflen >= len - 2) {
					break;
				}

				if (ptrcoldata[i] == '\0') {
					break;
				}
			}

			buf[buflen] = '\0';
			ast_debug(2, "buf is now set to '%s'\n", buf);
		}
		ast_debug(2, "buf is now set to '%s'\n", buf);

		if (resultset) {
			row = ast_calloc(1, sizeof(*row) + buflen + 1);
			if (!row) {
				ast_log(LOG_ERROR, "Unable to allocate space for more rows in this resultset.\n");
				status = "MEMERROR";
				goto end_acf_read;
			}
			strcpy((char *)row + sizeof(*row), buf);
			AST_LIST_INSERT_TAIL(resultset, row, list);

			/* Get next row */
			res = SQLFetch(stmt);
			if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) {
				if (res != SQL_NO_DATA) {
					ast_log(LOG_WARNING, "Error %d in FETCH [%s]\n", res, ast_str_buffer(sql));
				}
				/* Number of rows in the resultset */
				y++;