app_waitforring.c

Go to the documentation of this file.

/*
 * 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");