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
 */
 
/*** 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");