asterisk/funcs/func_srv.c

290 lines
7.2 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2010 Digium, Inc.
*
* 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 SRV Functions
*
* \author Mark Michelson <mmichelson@digium.com>
*
* \ingroup functions
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/srv.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/datastore.h"
#include "asterisk/channel.h"
/*** DOCUMENTATION
<function name="SRVQUERY" language="en_US">
<synopsis>
Initiate an SRV query.
</synopsis>
<syntax>
<parameter name="service" required="true">
<para>The service for which to look up SRV records. An example would be something
like <literal>_sip._udp.example.com</literal></para>
</parameter>
</syntax>
<description>
<para>This will do an SRV lookup of the given service.</para>
</description>
</function>
<function name="SRVRESULT" language="en_US">
<synopsis>
Retrieve results from an SRVQUERY.
</synopsis>
<syntax>
<parameter name="id" required="true">
<para>The identifier returned by the SRVQUERY function.</para>
</parameter>
<parameter name="resultnum" required="true">
<para>The number of the result that you want to retrieve.</para>
<para>Results start at <literal>1</literal>. If this argument is specified
as <literal>getnum</literal>, then it will return the total number of results
that are available.</para>
</parameter>
<parameter name="field" required="false">
<para>The field of the result to retrieve.</para>
<para>The fields that can be retrieved are:</para>
<enumlist>
<enum name="host"/>
<enum name="port"/>
<enum name="priority"/>
<enum name="weight"/>
</enumlist>
</parameter>
</syntax>
<description>
<para>This function will retrieve results from a previous use
of the SRVQUERY function.</para>
</description>
</function>
***/
struct srv_result_datastore {
struct srv_context *context;
char id[1];
};
static void srds_destroy_cb(void *data)
{
struct srv_result_datastore *datastore = data;
ast_srv_cleanup(&datastore->context);
ast_free(datastore);
}
static const struct ast_datastore_info srv_result_datastore_info = {
.type = "SRVQUERY",
.destroy = srds_destroy_cb,
};
static struct srv_context *srv_datastore_setup(const char *service, struct ast_channel *chan)
{
struct srv_result_datastore *srds;
struct ast_datastore *datastore;
const char *host;
unsigned short port;
if (!(srds = ast_calloc(1, sizeof(*srds) + strlen(service)))) {
return NULL;
}
ast_autoservice_start(chan);
if (ast_srv_lookup(&srds->context, service, &host, &port) < 0) {
ast_autoservice_stop(chan);
ast_log(LOG_NOTICE, "Error performing lookup of service '%s'\n", service);
ast_free(srds);
return NULL;
}
ast_autoservice_stop(chan);
strcpy(srds->id, service);
if (!(datastore = ast_datastore_alloc(&srv_result_datastore_info, srds->id))) {
ast_srv_cleanup(&srds->context);
ast_free(srds);
return NULL;
}
datastore->data = srds;
ast_channel_lock(chan);
ast_channel_datastore_add(chan, datastore);
ast_channel_unlock(chan);
return srds->context;
}
static int srv_query_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
struct ast_datastore *datastore;
if (!chan) {
ast_log(LOG_WARNING, "%s cannot be used without a channel\n", cmd);
return -1;
}
if (ast_strlen_zero(data)) {
ast_log(LOG_WARNING, "%s requires a service as an argument\n", cmd);
return -1;
}
/* If they already called SRVQUERY for this service once,
* we need to kill the old datastore.
*/
ast_channel_lock(chan);
datastore = ast_channel_datastore_find(chan, &srv_result_datastore_info, data);
ast_channel_unlock(chan);
if (datastore) {
ast_channel_datastore_remove(chan, datastore);
ast_datastore_free(datastore);
}
if (!srv_datastore_setup(data, chan)) {
return -1;
}
ast_copy_string(buf, data, len);
return 0;
}
static struct ast_custom_function srv_query_function = {
.name = "SRVQUERY",
.read = srv_query_read,
};
static int srv_result_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
struct srv_result_datastore *srds;
struct ast_datastore *datastore;
struct srv_context *srv_context;
char *parse;
const char *host;
unsigned short port, priority, weight;
unsigned int num;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(id);
AST_APP_ARG(resultnum);
AST_APP_ARG(field);
);
if (!chan) {
ast_log(LOG_WARNING, "%s cannot be used without a channel\n", cmd);
return -1;
}
if (ast_strlen_zero(data)) {
ast_log(LOG_WARNING, "%s requires two arguments (id and resultnum)\n", cmd);
return -1;
}
parse = ast_strdupa(data);
AST_STANDARD_APP_ARGS(args, parse);
ast_channel_lock(chan);
datastore = ast_channel_datastore_find(chan, &srv_result_datastore_info, args.id);
ast_channel_unlock(chan);
if (!datastore) {
/* They apparently decided to call SRVRESULT without first calling SRVQUERY.
* No problem, we'll do the SRV lookup now.
*/
srv_context = srv_datastore_setup(args.id, chan);
if (!srv_context) {
return -1;
}
} else {
srds = datastore->data;
srv_context = srds->context;
}
if (!strcasecmp(args.resultnum, "getnum")) {
snprintf(buf, len, "%u", ast_srv_get_record_count(srv_context));
return 0;
}
if (ast_strlen_zero(args.field)) {
ast_log(LOG_ERROR, "A field must be provided when requesting SRV data\n");
return -1;
}
if (sscanf(args.resultnum, "%30u", &num) != 1) {
ast_log(LOG_ERROR, "Invalid value '%s' for resultnum to %s\n", args.resultnum, cmd);
return -1;
}
if (ast_srv_get_nth_record(srv_context, num, &host, &port, &priority, &weight)) {
ast_log(LOG_ERROR, "Failed to get record number %u for %s\n", num, cmd);
return -1;
}
if (!strcasecmp(args.field, "host")) {
ast_copy_string(buf, host, len);
} else if (!strcasecmp(args.field, "port")) {
snprintf(buf, len, "%d", port);
} else if (!strcasecmp(args.field, "priority")) {
snprintf(buf, len, "%d", priority);
} else if (!strcasecmp(args.field, "weight")) {
snprintf(buf, len, "%d", weight);
} else {
ast_log(LOG_WARNING, "Unrecognized SRV field '%s'\n", args.field);
return -1;
}
return 0;
}
static struct ast_custom_function srv_result_function = {
.name = "SRVRESULT",
.read = srv_result_read,
};
static int unload_module(void)
{
int res = 0;
res |= ast_custom_function_unregister(&srv_query_function);
res |= ast_custom_function_unregister(&srv_result_function);
return res;
}
static int load_module(void)
{
int res = ast_custom_function_register(&srv_query_function);
if (res < 0) {
return AST_MODULE_LOAD_DECLINE;
}
res = ast_custom_function_register(&srv_result_function);
if (res < 0) {
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;;
}
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "SRV related dialplan functions");