160 lines
4.2 KiB
C
160 lines
4.2 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 2007, Digium, Inc.
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*
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* Joshua Colp <jcolp@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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*
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* \brief Simple two channel bridging module
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*
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* \author Joshua Colp <jcolp@digium.com>
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*
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* \ingroup bridges
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*/
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/*** MODULEINFO
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<support_level>core</support_level>
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***/
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#include "asterisk.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include "asterisk/module.h"
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#include "asterisk/channel.h"
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#include "asterisk/bridge.h"
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#include "asterisk/bridge_technology.h"
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#include "asterisk/frame.h"
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#include "asterisk/stream.h"
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static void simple_bridge_stream_topology_changed(struct ast_bridge *bridge,
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struct ast_bridge_channel *bridge_channel);
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static int simple_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
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{
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struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan;
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struct ast_channel *c1 = AST_LIST_LAST(&bridge->channels)->chan;
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/*
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* If this is the first channel we can't make it compatible...
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* unless we make it compatible with itself. O.o
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*/
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if (c0 == c1) {
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return 0;
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}
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if (ast_channel_make_compatible(c0, c1)) {
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return -1;
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}
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/* Align stream topologies */
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simple_bridge_stream_topology_changed(bridge, NULL);
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return 0;
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}
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static int simple_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
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{
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const struct ast_control_t38_parameters *t38_parameters;
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int defer = 0;
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if (!ast_bridge_queue_everyone_else(bridge, bridge_channel, frame)) {
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/* This frame was successfully queued so no need to defer */
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return 0;
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}
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/* Depending on the frame defer it so when the next channel joins it receives it */
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switch (frame->frametype) {
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case AST_FRAME_CONTROL:
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switch (frame->subclass.integer) {
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case AST_CONTROL_T38_PARAMETERS:
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t38_parameters = frame->data.ptr;
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switch (t38_parameters->request_response) {
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case AST_T38_REQUEST_NEGOTIATE:
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defer = -1;
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break;
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default:
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break;
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}
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break;
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default:
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break;
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}
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break;
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default:
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break;
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}
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return defer;
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}
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static struct ast_bridge_technology simple_bridge = {
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.name = "simple_bridge",
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.capabilities = AST_BRIDGE_CAPABILITY_1TO1MIX,
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.preference = AST_BRIDGE_PREFERENCE_BASE_1TO1MIX,
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.join = simple_bridge_join,
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.write = simple_bridge_write,
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.stream_topology_changed = simple_bridge_stream_topology_changed,
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};
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static void simple_bridge_stream_topology_changed(struct ast_bridge *bridge,
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struct ast_bridge_channel *bridge_channel)
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{
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struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan;
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struct ast_channel *c1 = AST_LIST_LAST(&bridge->channels)->chan;
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struct ast_stream_topology *t0 = ast_channel_get_stream_topology(c0);
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struct ast_stream_topology *t1 = ast_channel_get_stream_topology(c1);
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if (bridge_channel) {
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ast_bridge_channel_stream_map(bridge_channel);
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}
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/*
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* The bridge_channel should only be NULL after both channels join
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* the bridge and their topologies are being aligned.
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*/
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if (bridge_channel && ast_channel_get_stream_topology_change_source(
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bridge_channel->chan) == &simple_bridge) {
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return;
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}
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/* Align topologies according to size or first channel to join */
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if (ast_stream_topology_get_count(t0) < ast_stream_topology_get_count(t1)) {
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ast_channel_request_stream_topology_change(c0, t1, &simple_bridge);
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} else {
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ast_channel_request_stream_topology_change(c1, t0, &simple_bridge);
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}
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}
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static int unload_module(void)
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{
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ast_bridge_technology_unregister(&simple_bridge);
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return 0;
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}
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static int load_module(void)
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{
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if (ast_bridge_technology_register(&simple_bridge)) {
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unload_module();
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return AST_MODULE_LOAD_DECLINE;
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}
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return AST_MODULE_LOAD_SUCCESS;
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}
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AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Simple two channel bridging module");
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