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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2007, Digium, Inc.
*
* Joshua Colp <jcolp@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 Simple two channel bridging module
*
* \author Joshua Colp <jcolp@digium.com>
*
* \ingroup bridges
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/bridge.h"
#include "asterisk/bridge_technology.h"
#include "asterisk/frame.h"
#include "asterisk/stream.h"
static void simple_bridge_stream_topology_changed(struct ast_bridge *bridge,
struct ast_bridge_channel *bridge_channel);
static int simple_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
{
struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan;
struct ast_channel *c1 = AST_LIST_LAST(&bridge->channels)->chan;
/*
* If this is the first channel we can't make it compatible...
* unless we make it compatible with itself. O.o
*/
if (c0 == c1) {
return 0;
}
if (ast_channel_make_compatible(c0, c1)) {
return -1;
}
/* Align stream topologies */
simple_bridge_stream_topology_changed(bridge, NULL);
return 0;
}
static int simple_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
{
const struct ast_control_t38_parameters *t38_parameters;
int defer = 0;
if (!ast_bridge_queue_everyone_else(bridge, bridge_channel, frame)) {
/* This frame was successfully queued so no need to defer */
return 0;
}
/* Depending on the frame defer it so when the next channel joins it receives it */
switch (frame->frametype) {
case AST_FRAME_CONTROL:
switch (frame->subclass.integer) {
case AST_CONTROL_T38_PARAMETERS:
t38_parameters = frame->data.ptr;
switch (t38_parameters->request_response) {
case AST_T38_REQUEST_NEGOTIATE:
defer = -1;
break;
default:
break;
}
break;
default:
break;
}
break;
default:
break;
}
return defer;
}
static struct ast_bridge_technology simple_bridge = {
.name = "simple_bridge",
.capabilities = AST_BRIDGE_CAPABILITY_1TO1MIX,
.preference = AST_BRIDGE_PREFERENCE_BASE_1TO1MIX,
.join = simple_bridge_join,
.write = simple_bridge_write,
.stream_topology_changed = simple_bridge_stream_topology_changed,
};
static void simple_bridge_stream_topology_changed(struct ast_bridge *bridge,
struct ast_bridge_channel *bridge_channel)
{
struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan;
struct ast_channel *c1 = AST_LIST_LAST(&bridge->channels)->chan;
struct ast_stream_topology *t0 = ast_channel_get_stream_topology(c0);
struct ast_stream_topology *t1 = ast_channel_get_stream_topology(c1);
if (bridge_channel) {
ast_bridge_channel_stream_map(bridge_channel);
}
/*
* The bridge_channel should only be NULL after both channels join
* the bridge and their topologies are being aligned.
*/
if (bridge_channel && ast_channel_get_stream_topology_change_source(
bridge_channel->chan) == &simple_bridge) {
return;
}
/* Align topologies according to size or first channel to join */
if (ast_stream_topology_get_count(t0) < ast_stream_topology_get_count(t1)) {
ast_channel_request_stream_topology_change(c0, t1, &simple_bridge);
} else {
ast_channel_request_stream_topology_change(c1, t0, &simple_bridge);
}
}
static int unload_module(void)
{
ast_bridge_technology_unregister(&simple_bridge);
return 0;
}
static int load_module(void)
{
if (ast_bridge_technology_register(&simple_bridge)) {
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Simple two channel bridging module");
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