app_waitforring.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <[email protected]>
 *
 * 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 Wait for Ring Application
 *
 * \author Mark Spencer <[email protected]>
 *
 * \ingroup applications
 */

/*** MODULEINFO
 <support_level>extended</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"

/*** DOCUMENTATION
 <application name="WaitForRing" language="en_US">
 <synopsis>
 Wait for Ring Application.
 </synopsis>
 <syntax>
 <parameter name="timeout" required="true" />
 </syntax>
 <description>
 <para>Returns <literal>0</literal> after waiting at least <replaceable>timeout</replaceable> seconds,
 and only after the next ring has completed. Returns <literal>0</literal> on success or
 <literal>-1</literal> on hangup.</para>
 </description>
 </application>
 ***/

static char *app = "WaitForRing";

static int waitforring_exec(struct ast_channel *chan, const char *data)
{
 struct ast_frame *f;
 struct ast_silence_generator *silgen = NULL;
 int res = 0;
 double s;
 int timeout_ms;
 int ms;
 struct timeval start = ast_tvnow();

 if (!data || (sscanf(data, "%30lg", &s) != 1)) {
 ast_log(LOG_WARNING, "WaitForRing requires an argument (minimum seconds)\n");
 return 0;
 }

 if (s < 0.0) {
 ast_log(LOG_WARNING, "Invalid timeout provided for WaitForRing (%lg)\n", s);
 return 0;
 }

 if (ast_opt_transmit_silence) {
 silgen = ast_channel_start_silence_generator(chan);
 }

 timeout_ms = s * 1000.0;
 while ((ms = ast_remaining_ms(start, timeout_ms))) {
 ms = ast_waitfor(chan, ms);
 if (ms < 0) {
 res = -1;
 break;
 }
 if (ms > 0) {
 f = ast_read(chan);
 if (!f) {
 res = -1;
 break;
 }
 if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass.integer == AST_CONTROL_RING)) {
 ast_verb(3, "Got a ring but still waiting for timeout\n");
 }
 ast_frfree(f);
 }
 }
 /* Now we're really ready for the ring */
 if (!res) {
 for (;;) {
 int wait_res = ast_waitfor(chan, -1);
 if (wait_res < 0) {
 res = -1;
 break;
 } else {
 f = ast_read(chan);
 if (!f) {
 res = -1;
 break;
 }
 if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass.integer == AST_CONTROL_RING)) {
 ast_verb(3, "Got a ring after the timeout\n");
 ast_frfree(f);
 break;
 }
 ast_frfree(f);
 }
 }
 }

 if (silgen) {
 ast_channel_stop_silence_generator(chan, silgen);
 }

 return res;
}

static int unload_module(void)
{
 return ast_unregister_application(app);
}

static int load_module(void)
{
 return ast_register_application_xml(app, waitforring_exec);
}

AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "Waits until first ring after time");