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>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#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/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";

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[2048];
	char sql_write[2048];
	char sql_insert[2048];
	unsigned int flags;
	int rowlimit;
	struct ast_custom_function *acf;
};

static void odbc_datastore_free(void *data);

static 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];
};

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;
	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);
}

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

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

	return stmt;
}

/*
 * 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, 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";

	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);
	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_release(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);
	ast_str_substitute_variables(&insertbuf, 0, chan, query->sql_insert);

	if (bogus_chan) {
		chan = ast_channel_release(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 = 0; dsn < 5; dsn++) {
		if (!ast_strlen_zero(query->writehandle[dsn])) {
			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]))) {
				transactional = 1;
			} else {
				obj = ast_odbc_request_obj(query->writehandle[dsn], 0);
				transactional = 0;
			}

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

			if (obj && !transactional) {
				ast_odbc_release_obj(obj);
				obj = NULL;
			}
		}
	}

	if (stmt) {
		SQLRowCount(stmt, &rows);
	}

	if (stmt && rows == 0 && ast_str_strlen(insertbuf) != 0) {
		SQLCloseCursor(stmt);
		SQLFreeHandle(SQL_HANDLE_STMT, stmt);
		if (obj && !transactional) {
			ast_odbc_release_obj(obj);
			obj = NULL;
		}

		for (transactional = 0, dsn = 0; dsn < 5; dsn++) {
			if (!ast_strlen_zero(query->writehandle[dsn])) {
				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 if (obj) {
					ast_odbc_release_obj(obj);
					obj = NULL;
				}

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

	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 (stmt) {
		SQLCloseCursor(stmt);
		SQLFreeHandle(SQL_HANDLE_STMT, stmt);
	}
	if (obj && !transactional) {
		ast_odbc_release_obj(obj);
		obj = NULL;
	}

	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, 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";

	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_release(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 = 0; dsn < 5; dsn++) {
		if (!ast_strlen_zero(query->readhandle[dsn])) {
			obj = ast_odbc_request_obj(query->readhandle[dsn], 0);
			if (obj) {
				stmt = ast_odbc_direct_execute(obj, generic_execute, ast_str_buffer(sql));
			}
		}
		if (stmt) {
			break;
		}
		if (obj) {
			ast_odbc_release_obj(obj);
			obj = NULL;
		}
	}

	if (!stmt) {
		ast_log(LOG_ERROR, "Unable to execute query [%s]\n", ast_str_buffer(sql));
		if (obj) {
			ast_odbc_release_obj(obj);
			obj = NULL;
		}
		if (!bogus_chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			ast_autoservice_stop(chan);
		}
		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);
		ast_odbc_release_obj(obj);
		obj = NULL;
		if (!bogus_chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			ast_autoservice_stop(chan);
		}
		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);
		ast_odbc_release_obj(obj);
		obj = NULL;
		if (!bogus_chan) {
			pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
			ast_autoservice_stop(chan);
		}
		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) {
				ast_free(resultset);
				SQLCloseCursor(stmt);
				SQLFreeHandle(SQL_HANDLE_STMT, stmt);
				ast_odbc_release_obj(obj);
				obj = NULL;
				pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
				if (chan)
					ast_autoservice_stop(chan);
				if (bogus_chan) {
					ast_channel_release(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");
						ast_free(resultset);
						SQLCloseCursor(stmt);
						SQLFreeHandle(SQL_HANDLE_STMT, stmt);
						ast_odbc_release_obj(obj);
						obj = NULL;
						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++;
				break;
			}
		}
	}

end_acf_read:
	if (!bogus_chan) {
		snprintf(rowcount, sizeof(rowcount), "%d", y);
		pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
		pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
		pbx_builtin_setvar_helper(chan, "~ODBCFIELDS~", ast_str_buffer(colnames));
		if (resultset) {
			int uid;
			struct ast_datastore *odbc_store;
			if (multirow) {
				uid = ast_atomic_fetchadd_int(&resultcount, +1) + 1;
				snprintf(buf, len, "%d", uid);
			} else {
				/* Name of the query is name of the resultset */
				ast_copy_string(buf, cmd, len);

				/* If there's one with the same name already, free it */
				ast_channel_lock(chan);
				if ((odbc_store = ast_channel_datastore_find(chan, &odbc_info, buf))) {
					ast_channel_datastore_remove(chan, odbc_store);
					odbc_datastore_free(odbc_store->data);
					ast_free(odbc_store);
				}
				ast_channel_unlock(chan);
			}
			odbc_store = ast_datastore_alloc(&odbc_info, buf);
			if (!odbc_store) {
				ast_log(LOG_ERROR, "Rows retrieved, but unable to store it in the channel.  Results fail.\n");
				odbc_datastore_free(resultset);
				SQLCloseCursor(stmt);
				SQLFreeHandle(SQL_HANDLE_STMT, stmt);
				ast_odbc_release_obj(obj);
				obj = NULL;
				pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
				ast_autoservice_stop(chan);
				return -1;
			}
			odbc_store->data = resultset;
			ast_channel_datastore_add(chan, odbc_store);
		}
	}
	SQLCloseCursor(stmt);
	SQLFreeHandle(SQL_HANDLE_STMT, stmt);
	ast_odbc_release_obj(obj);
	obj = NULL;
	if (resultset && !multirow) {
		/* Fetch the first resultset */
		if (!acf_fetch(chan, "", buf, buf, len)) {
			buf[0] = '\0';
		}
	}
	if (!bogus_chan) {
		ast_autoservice_stop(chan);
	}
	return 0;
}

static int acf_escape(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
	char *out = buf;

	for (; *data && out - buf < len; data++) {
		if (*data == '\'') {
			*out = '\'';
			out++;
		}
		*out++ = *data;
	}
	*out = '\0';

	return 0;
}

static struct ast_custom_function escape_function = {
	.name = "SQL_ESC",
	.read = acf_escape,
	.write = NULL,
};

static int acf_fetch(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
	struct ast_datastore *store;
	struct odbc_datastore *resultset;
	struct odbc_datastore_row *row;
	store = ast_channel_datastore_find(chan, &odbc_info, data);
	if (!store) {
		pbx_builtin_setvar_helper(chan, "ODBC_FETCH_STATUS", "FAILURE");
		return -1;
	}
	resultset = store->data;
	AST_LIST_LOCK(resultset);
	row = AST_LIST_REMOVE_HEAD(resultset, list);
	AST_LIST_UNLOCK(resultset);
	if (!row) {
		/* Cleanup datastore */
		ast_channel_datastore_remove(chan, store);
		ast_datastore_free(store);
		pbx_builtin_setvar_helper(chan, "ODBC_FETCH_STATUS", "FAILURE");
		return -1;
	}
	pbx_builtin_setvar_helper(chan, "~ODBCFIELDS~", resultset->names);
	ast_copy_string(buf, row->data, len);
	ast_free(row);
	pbx_builtin_setvar_helper(chan, "ODBC_FETCH_STATUS", "SUCCESS");
	return 0;
}

static struct ast_custom_function fetch_function = {
	.name = "ODBC_FETCH",
	.read = acf_fetch,
	.write = NULL,
};

static char *app_odbcfinish = "ODBCFinish";

static int exec_odbcfinish(struct ast_channel *chan, const char *data)
{
	struct ast_datastore *store = ast_channel_datastore_find(chan, &odbc_info, data);
	if (!store) /* Already freed; no big deal. */
		return 0;
	ast_channel_datastore_remove(chan, store);
	ast_datastore_free(store);
	return 0;
}

static int init_acf_query(struct ast_config *cfg, char *catg, struct acf_odbc_query **query)
{
	const char *tmp;
	int i;

	if (!cfg || !catg) {
		return EINVAL;
	}

	*query = ast_calloc(1, sizeof(struct acf_odbc_query));
	if (! (*query))
		return ENOMEM;

	if (((tmp = ast_variable_retrieve(cfg, catg, "writehandle"))) || ((tmp = ast_variable_retrieve(cfg, catg, "dsn")))) {
		char *tmp2 = ast_strdupa(tmp);
		AST_DECLARE_APP_ARGS(writeconf,
			AST_APP_ARG(dsn)[5];
		);
		AST_STANDARD_APP_ARGS(writeconf, tmp2);
		for (i = 0; i < 5; i++) {
			if (!ast_strlen_zero(writeconf.dsn[i]))
				ast_copy_string((*query)->writehandle[i], writeconf.dsn[i], sizeof((*query)->writehandle[i]));
		}
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "readhandle"))) {
		char *tmp2 = ast_strdupa(tmp);
		AST_DECLARE_APP_ARGS(readconf,
			AST_APP_ARG(dsn)[5];
		);
		AST_STANDARD_APP_ARGS(readconf, tmp2);
		for (i = 0; i < 5; i++) {
			if (!ast_strlen_zero(readconf.dsn[i]))
				ast_copy_string((*query)->readhandle[i], readconf.dsn[i], sizeof((*query)->readhandle[i]));
		}
	} else {
		/* If no separate readhandle, then use the writehandle for reading */
		for (i = 0; i < 5; i++) {
			if (!ast_strlen_zero((*query)->writehandle[i]))
				ast_copy_string((*query)->readhandle[i], (*query)->writehandle[i], sizeof((*query)->readhandle[i]));
		}
 	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "readsql")))
		ast_copy_string((*query)->sql_read, tmp, sizeof((*query)->sql_read));
	else if ((tmp = ast_variable_retrieve(cfg, catg, "read"))) {
		ast_log(LOG_WARNING, "Parameter 'read' is deprecated for category %s.  Please use 'readsql' instead.\n", catg);
		ast_copy_string((*query)->sql_read, tmp, sizeof((*query)->sql_read));
	}

	if (!ast_strlen_zero((*query)->sql_read) && ast_strlen_zero((*query)->readhandle[0])) {
		ast_free(*query);
		*query = NULL;
		ast_log(LOG_ERROR, "There is SQL, but no ODBC class to be used for reading: %s\n", catg);
		return EINVAL;
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "writesql")))
		ast_copy_string((*query)->sql_write, tmp, sizeof((*query)->sql_write));
	else if ((tmp = ast_variable_retrieve(cfg, catg, "write"))) {
		ast_log(LOG_WARNING, "Parameter 'write' is deprecated for category %s.  Please use 'writesql' instead.\n", catg);
		ast_copy_string((*query)->sql_write, tmp, sizeof((*query)->sql_write));
	}

	if (!ast_strlen_zero((*query)->sql_write) && ast_strlen_zero((*query)->writehandle[0])) {
		ast_free(*query);
		*query = NULL;
		ast_log(LOG_ERROR, "There is SQL, but no ODBC class to be used for writing: %s\n", catg);
		return EINVAL;
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "insertsql"))) {
		ast_copy_string((*query)->sql_insert, tmp, sizeof((*query)->sql_insert));
	}

	/* Allow escaping of embedded commas in fields to be turned off */
	ast_set_flag((*query), OPT_ESCAPECOMMAS);
	if ((tmp = ast_variable_retrieve(cfg, catg, "escapecommas"))) {
		if (ast_false(tmp))
			ast_clear_flag((*query), OPT_ESCAPECOMMAS);
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "mode"))) {
		if (strcasecmp(tmp, "multirow") == 0)
			ast_set_flag((*query), OPT_MULTIROW);
		if ((tmp = ast_variable_retrieve(cfg, catg, "rowlimit")))
			sscanf(tmp, "%30d", &((*query)->rowlimit));
	}

	(*query)->acf = ast_calloc(1, sizeof(struct ast_custom_function));
	if (! (*query)->acf) {
		ast_free(*query);
		*query = NULL;
		return ENOMEM;
	}
	if (ast_string_field_init((*query)->acf, 128)) {
		ast_free((*query)->acf);
		ast_free(*query);
		*query = NULL;
		return ENOMEM;
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "prefix")) && !ast_strlen_zero(tmp)) {
		if (asprintf((char **)&((*query)->acf->name), "%s_%s", tmp, catg) < 0) {
			ast_log(LOG_WARNING, "asprintf() failed: %s\n", strerror(errno));
		}
	} else {
		if (asprintf((char **)&((*query)->acf->name), "ODBC_%s", catg) < 0) {
			ast_log(LOG_WARNING, "asprintf() failed: %s\n", strerror(errno));
		}
	}

	if (!((*query)->acf->name)) {
		ast_string_field_free_memory((*query)->acf);
		ast_free((*query)->acf);
		ast_free(*query);
		*query = NULL;
		return ENOMEM;
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "syntax")) && !ast_strlen_zero(tmp)) {
		ast_string_field_build((*query)->acf, syntax, "%s(%s)", (*query)->acf->name, tmp);
	} else {
		ast_string_field_build((*query)->acf, syntax, "%s(<arg1>[...[,<argN>]])", (*query)->acf->name);
	}

	if (ast_strlen_zero((*query)->acf->syntax)) {
		ast_free((char *)(*query)->acf->name);
		ast_string_field_free_memory((*query)->acf);
		ast_free((*query)->acf);
		ast_free(*query);
		*query = NULL;
		return ENOMEM;
	}

	if ((tmp = ast_variable_retrieve(cfg, catg, "synopsis")) && !ast_strlen_zero(tmp)) {
		ast_string_field_set((*query)->acf, synopsis, tmp);
	} else {
		ast_string_field_set((*query)->acf, synopsis, "Runs the referenced query with the specified arguments");
	}

	if (ast_strlen_zero((*query)->acf->synopsis)) {
		ast_free((char *)(*query)->acf->name);
		ast_string_field_free_memory((*query)->acf);
		ast_free((*query)->acf);
		ast_free(*query);
		*query = NULL;
		return ENOMEM;
	}

	if (!ast_strlen_zero((*query)->sql_read) && !ast_strlen_zero((*query)->sql_write)) {
		ast_string_field_build((*query)->acf, desc,
					"Runs the following query, as defined in func_odbc.conf, performing\n"
				   	"substitution of the arguments into the query as specified by ${ARG1},\n"
					"${ARG2}, ... ${ARGn}.  When setting the function, the values are provided\n"
					"either in whole as ${VALUE} or parsed as ${VAL1}, ${VAL2}, ... ${VALn}.\n"
					"%s"
					"\nRead:\n%s\n\nWrite:\n%s\n%s%s%s",
					ast_strlen_zero((*query)->sql_insert) ? "" :
						"If the write query affects no rows, the insert query will be\n"
						"performed.\n",
					(*query)->sql_read,
					(*query)->sql_write,
					ast_strlen_zero((*query)->sql_insert) ? "" : "Insert:\n",
					ast_strlen_zero((*query)->sql_insert) ? "" : (*query)->sql_insert,
					ast_strlen_zero((*query)->sql_insert) ? "" : "\n");
	} else if (!ast_strlen_zero((*query)->sql_read)) {