app_waitforring.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.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 Wait for Ring Application
 *
 * \author Mark Spencer <markster@digium.com>
 * 
 * \ingroup applications
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 239714 $")

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

static char *synopsis = "Wait for Ring Application";

static char *desc = "  WaitForRing(timeout):\n"
"Returns 0 after waiting at least timeout seconds. and\n"
"only after the next ring has completed.  Returns 0 on\n"
"success or -1 on hangup\n";

static char *app = "WaitForRing";


static int waitforring_exec(struct ast_channel *chan, void *data)
{
   struct ast_frame *f;
   struct ast_silence_generator *silgen = NULL;
   int res = 0;
   double s;
   int ms;

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

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

   ms = s * 1000.0;
   while (ms > 0) {
      ms = ast_waitfor(chan, ms);
      if (ms < 0) {
         res = ms;
         break;
      }
      if (ms > 0) {
         f = ast_read(chan);
         if (!f) {
            res = -1;
            break;
         }
         if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == 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) {
      ms = 99999999;
      while(ms > 0) {
         ms = ast_waitfor(chan, ms);
         if (ms < 0) {
            res = ms;
            break;
         }
         if (ms > 0) {
            f = ast_read(chan);
            if (!f) {
               res = -1;
               break;
            }
            if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == 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(app, waitforring_exec, synopsis, desc);
}

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