Simple lock, assignment, unlock sandwich optimization.
[asterisk/asterisk.git] / bridges / bridge_native_rtp.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 2013, Digium, Inc.
5  *
6  * Joshua Colp <jcolp@digium.com>
7  *
8  * See http://www.asterisk.org for more information about
9  * the Asterisk project. Please do not directly contact
10  * any of the maintainers of this project for assistance;
11  * the project provides a web site, mailing lists and IRC
12  * channels for your use.
13  *
14  * This program is free software, distributed under the terms of
15  * the GNU General Public License Version 2. See the LICENSE file
16  * at the top of the source tree.
17  */
18
19 /*! \file
20  *
21  * \brief Native RTP bridging technology module
22  *
23  * \author Joshua Colp <jcolp@digium.com>
24  *
25  * \ingroup bridges
26  */
27
28 /*** MODULEINFO
29         <support_level>core</support_level>
30  ***/
31
32 #include "asterisk.h"
33
34 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
35
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <sys/types.h>
40 #include <sys/stat.h>
41
42 #include "asterisk/module.h"
43 #include "asterisk/channel.h"
44 #include "asterisk/bridging.h"
45 #include "asterisk/bridging_technology.h"
46 #include "asterisk/frame.h"
47 #include "asterisk/rtp_engine.h"
48 #include "asterisk/audiohook.h"
49
50 /*! \brief Forward declarations for frame hook usage */
51 static int native_rtp_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel);
52 static void native_rtp_bridge_leave(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel);
53
54 /*! \brief Internal structure which contains information about bridged RTP channels */
55 struct native_rtp_bridge_data {
56         /*! \brief Framehook used to intercept certain control frames */
57         int id;
58 };
59
60 /*! \brief Frame hook that is called to intercept hold/unhold */
61 static struct ast_frame *native_rtp_framehook(struct ast_channel *chan, struct ast_frame *f, enum ast_framehook_event event, void *data)
62 {
63         RAII_VAR(struct ast_bridge *, bridge, NULL, ao2_cleanup);
64
65         if (!f || (event != AST_FRAMEHOOK_EVENT_WRITE)) {
66                 return f;
67         }
68
69         ast_channel_lock(chan);
70         bridge = ast_channel_get_bridge(chan);
71         ast_channel_unlock(chan);
72
73         /* It's safe for NULL to be passed to both of these, bridge_channel isn't used at all */
74         if (bridge) {
75                 if (f->subclass.integer == AST_CONTROL_HOLD) {
76                         native_rtp_bridge_leave(ast_channel_internal_bridge(chan), NULL);
77                 } else if ((f->subclass.integer == AST_CONTROL_UNHOLD) || (f->subclass.integer == AST_CONTROL_UPDATE_RTP_PEER)) {
78                         native_rtp_bridge_join(ast_channel_internal_bridge(chan), NULL);
79                 }
80         }
81
82         return f;
83 }
84
85 /*! \brief Internal helper function which checks whether the channels are compatible with our native bridging */
86 static int native_rtp_bridge_capable(struct ast_channel *chan)
87 {
88         if (ast_channel_monitor(chan) || (ast_channel_audiohooks(chan) &&
89                 !ast_audiohook_write_list_empty(ast_channel_audiohooks(chan))) ||
90                 !ast_framehook_list_is_empty(ast_channel_framehooks(chan))) {
91                 return 0;
92         } else {
93                 return 1;
94         }
95 }
96
97 /*! \brief Internal helper function which gets all RTP information (glue and instances) relating to the given channels */
98 static enum ast_rtp_glue_result native_rtp_bridge_get(struct ast_channel *c0, struct ast_channel *c1, struct ast_rtp_glue **glue0,
99         struct ast_rtp_glue **glue1, struct ast_rtp_instance **instance0, struct ast_rtp_instance **instance1,
100         struct ast_rtp_instance **vinstance0, struct ast_rtp_instance **vinstance1)
101 {
102         enum ast_rtp_glue_result audio_glue0_res = AST_RTP_GLUE_RESULT_FORBID, video_glue0_res = AST_RTP_GLUE_RESULT_FORBID;
103         enum ast_rtp_glue_result audio_glue1_res = AST_RTP_GLUE_RESULT_FORBID, video_glue1_res = AST_RTP_GLUE_RESULT_FORBID;
104
105         if (!(*glue0 = ast_rtp_instance_get_glue(ast_channel_tech(c0)->type)) ||
106                 (c1 && !(*glue1 = ast_rtp_instance_get_glue(ast_channel_tech(c1)->type)))) {
107                 return AST_RTP_GLUE_RESULT_FORBID;
108         }
109
110         audio_glue0_res = (*glue0)->get_rtp_info(c0, instance0);
111         video_glue0_res = (*glue0)->get_vrtp_info ? (*glue0)->get_vrtp_info(c0, vinstance0) : AST_RTP_GLUE_RESULT_FORBID;
112
113         if (c1) {
114                 audio_glue1_res = (*glue1)->get_rtp_info(c1, instance1);
115                 video_glue1_res = (*glue1)->get_vrtp_info ? (*glue1)->get_vrtp_info(c1, vinstance1) : AST_RTP_GLUE_RESULT_FORBID;
116         }
117
118         /* Apply any limitations on direct media bridging that may be present */
119         if (audio_glue0_res == audio_glue1_res && audio_glue1_res == AST_RTP_GLUE_RESULT_REMOTE) {
120                 if ((*glue0)->allow_rtp_remote && !((*glue0)->allow_rtp_remote(c0, *instance1))) {
121                         /* If the allow_rtp_remote indicates that remote isn't allowed, revert to local bridge */
122                         audio_glue0_res = audio_glue1_res = AST_RTP_GLUE_RESULT_LOCAL;
123                 } else if ((*glue1)->allow_rtp_remote && !((*glue1)->allow_rtp_remote(c1, *instance0))) {
124                         audio_glue0_res = audio_glue1_res = AST_RTP_GLUE_RESULT_LOCAL;
125                 }
126         }
127         if (c1 && video_glue0_res == video_glue1_res && video_glue1_res == AST_RTP_GLUE_RESULT_REMOTE) {
128                 if ((*glue0)->allow_vrtp_remote && !((*glue0)->allow_vrtp_remote(c0, *instance1))) {
129                         /* if the allow_vrtp_remote indicates that remote isn't allowed, revert to local bridge */
130                         video_glue0_res = video_glue1_res = AST_RTP_GLUE_RESULT_LOCAL;
131                 } else if ((*glue1)->allow_vrtp_remote && !((*glue1)->allow_vrtp_remote(c1, *instance0))) {
132                         video_glue0_res = video_glue1_res = AST_RTP_GLUE_RESULT_LOCAL;
133                 }
134         }
135
136         /* If we are carrying video, and both sides are not going to remotely bridge... fail the native bridge */
137         if (video_glue0_res != AST_RTP_GLUE_RESULT_FORBID && (audio_glue0_res != AST_RTP_GLUE_RESULT_REMOTE || video_glue0_res != AST_RTP_GLUE_RESULT_REMOTE)) {
138                 audio_glue0_res = AST_RTP_GLUE_RESULT_FORBID;
139         }
140         if (c1 && video_glue1_res != AST_RTP_GLUE_RESULT_FORBID && (audio_glue1_res != AST_RTP_GLUE_RESULT_REMOTE || video_glue1_res != AST_RTP_GLUE_RESULT_REMOTE)) {
141                 audio_glue1_res = AST_RTP_GLUE_RESULT_FORBID;
142         }
143
144         /* If any sort of bridge is forbidden just completely bail out and go back to generic bridging */
145         if (audio_glue0_res == AST_RTP_GLUE_RESULT_FORBID || (c1 && audio_glue1_res == AST_RTP_GLUE_RESULT_FORBID)) {
146                 return AST_RTP_GLUE_RESULT_FORBID;
147         }
148
149         return audio_glue0_res;
150 }
151
152 static int native_rtp_bridge_compatible(struct ast_bridge *bridge)
153 {
154         struct ast_bridge_channel *c0 = AST_LIST_FIRST(&bridge->channels);
155         struct ast_bridge_channel *c1 = AST_LIST_LAST(&bridge->channels);
156         enum ast_rtp_glue_result native_type;
157         struct ast_rtp_glue *glue0, *glue1;
158         struct ast_rtp_instance *instance0 = NULL, *instance1 = NULL, *vinstance0 = NULL, *vinstance1 = NULL;
159         RAII_VAR(struct ast_format_cap *, cap0, ast_format_cap_alloc_nolock(), ast_format_cap_destroy);
160         RAII_VAR(struct ast_format_cap *, cap1, ast_format_cap_alloc_nolock(), ast_format_cap_destroy);
161         int read_ptime0, read_ptime1, write_ptime0, write_ptime1;
162
163         /* We require two channels before even considering native bridging */
164         if (bridge->num_channels != 2) {
165                 ast_debug(1, "Bridge '%s' can not use native RTP bridge as two channels are required\n",
166                         bridge->uniqueid);
167                 return 0;
168         }
169
170         if (!native_rtp_bridge_capable(c0->chan)) {
171                 ast_debug(1, "Bridge '%s' can not use native RTP bridge as channel '%s' has features which prevent it\n",
172                         bridge->uniqueid, ast_channel_name(c0->chan));
173                 return 0;
174         }
175
176         if (!native_rtp_bridge_capable(c1->chan)) {
177                 ast_debug(1, "Bridge '%s' can not use native RTP bridge as channel '%s' has features which prevent it\n",
178                         bridge->uniqueid, ast_channel_name(c1->chan));
179                 return 0;
180         }
181
182         if ((native_type = native_rtp_bridge_get(c0->chan, c1->chan, &glue0, &glue1, &instance0, &instance1, &vinstance0, &vinstance1))
183                 == AST_RTP_GLUE_RESULT_FORBID) {
184                 ast_debug(1, "Bridge '%s' can not use native RTP bridge as it was forbidden while getting details\n",
185                         bridge->uniqueid);
186                 return 0;
187         }
188
189         if (ao2_container_count(c0->features->dtmf_hooks) && ast_rtp_instance_dtmf_mode_get(instance0)) {
190                 ast_debug(1, "Bridge '%s' can not use native RTP bridge as channel '%s' has DTMF hooks\n",
191                         bridge->uniqueid, ast_channel_name(c0->chan));
192                 return 0;
193         }
194
195         if (ao2_container_count(c1->features->dtmf_hooks) && ast_rtp_instance_dtmf_mode_get(instance1)) {
196                 ast_debug(1, "Bridge '%s' can not use native RTP bridge as channel '%s' has DTMF hooks\n",
197                         bridge->uniqueid, ast_channel_name(c1->chan));
198                 return 0;
199         }
200
201         if ((native_type == AST_RTP_GLUE_RESULT_LOCAL) && ((ast_rtp_instance_get_engine(instance0)->local_bridge !=
202                 ast_rtp_instance_get_engine(instance1)->local_bridge) ||
203                 (ast_rtp_instance_get_engine(instance0)->dtmf_compatible &&
204                         !ast_rtp_instance_get_engine(instance0)->dtmf_compatible(c0->chan, instance0, c1->chan, instance1)))) {
205                 ast_debug(1, "Bridge '%s' can not use local native RTP bridge as local bridge or DTMF is not compatible\n",
206                         bridge->uniqueid);
207                 return 0;
208         }
209
210         /* Make sure that codecs match */
211         if (glue0->get_codec) {
212                 glue0->get_codec(c0->chan, cap0);
213         }
214         if (glue1->get_codec) {
215                 glue1->get_codec(c1->chan, cap1);
216         }
217         if (!ast_format_cap_is_empty(cap0) && !ast_format_cap_is_empty(cap1) && !ast_format_cap_has_joint(cap0, cap1)) {
218                 char tmp0[256] = { 0, }, tmp1[256] = { 0, };
219
220                 ast_debug(1, "Channel codec0 = %s is not codec1 = %s, cannot native bridge in RTP.\n",
221                         ast_getformatname_multiple(tmp0, sizeof(tmp0), cap0),
222                         ast_getformatname_multiple(tmp1, sizeof(tmp1), cap1));
223                 return 0;
224         }
225
226         read_ptime0 = (ast_codec_pref_getsize(&ast_rtp_instance_get_codecs(instance0)->pref, ast_channel_rawreadformat(c0->chan))).cur_ms;
227         read_ptime1 = (ast_codec_pref_getsize(&ast_rtp_instance_get_codecs(instance1)->pref, ast_channel_rawreadformat(c1->chan))).cur_ms;
228         write_ptime0 = (ast_codec_pref_getsize(&ast_rtp_instance_get_codecs(instance0)->pref, ast_channel_rawwriteformat(c0->chan))).cur_ms;
229         write_ptime1 = (ast_codec_pref_getsize(&ast_rtp_instance_get_codecs(instance1)->pref, ast_channel_rawwriteformat(c1->chan))).cur_ms;
230
231         if (read_ptime0 != write_ptime1 || read_ptime1 != write_ptime0) {
232                 ast_debug(1, "Packetization differs between RTP streams (%d != %d or %d != %d). Cannot native bridge in RTP\n",
233                                 read_ptime0, write_ptime1, read_ptime1, write_ptime0);
234                 return 0;
235         }
236
237         return 1;
238 }
239
240 /*! \brief Helper function which adds frame hook to bridge channel */
241 static int native_rtp_bridge_framehook_attach(struct ast_bridge_channel *bridge_channel)
242 {
243         struct native_rtp_bridge_data *data = ao2_alloc(sizeof(*data), NULL);
244         static struct ast_framehook_interface hook = {
245                 .version = AST_FRAMEHOOK_INTERFACE_VERSION,
246                 .event_cb = native_rtp_framehook,
247         };
248
249         if (!data) {
250                 return -1;
251         }
252
253         ast_channel_lock(bridge_channel->chan);
254         data->id = ast_framehook_attach(bridge_channel->chan, &hook);
255         ast_channel_unlock(bridge_channel->chan);
256         if (!data->id < 0) {
257                 ao2_cleanup(data);
258                 return -1;
259         }
260
261         bridge_channel->bridge_pvt = data;
262
263         return 0;
264 }
265
266 /*! \brief Helper function which removes frame hook from bridge channel */
267 static void native_rtp_bridge_framehook_detach(struct ast_bridge_channel *bridge_channel)
268 {
269         RAII_VAR(struct native_rtp_bridge_data *, data, bridge_channel->bridge_pvt, ao2_cleanup);
270
271         if (!data) {
272                 return;
273         }
274
275         ast_channel_lock(bridge_channel->chan);
276         ast_framehook_detach(bridge_channel->chan, data->id);
277         ast_channel_unlock(bridge_channel->chan);
278         bridge_channel->bridge_pvt = NULL;
279 }
280
281 static int native_rtp_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
282 {
283         struct ast_bridge_channel *c0 = AST_LIST_FIRST(&bridge->channels);
284         struct ast_bridge_channel *c1 = AST_LIST_LAST(&bridge->channels);
285         enum ast_rtp_glue_result native_type;
286         struct ast_rtp_glue *glue0, *glue1;
287         struct ast_rtp_instance *instance0 = NULL, *instance1 = NULL, *vinstance0 = NULL;
288         struct ast_rtp_instance *vinstance1 = NULL, *tinstance0 = NULL, *tinstance1 = NULL;
289         RAII_VAR(struct ast_format_cap *, cap0, ast_format_cap_alloc_nolock(), ast_format_cap_destroy);
290         RAII_VAR(struct ast_format_cap *, cap1, ast_format_cap_alloc_nolock(), ast_format_cap_destroy);
291
292         native_rtp_bridge_framehook_detach(c0);
293         if (native_rtp_bridge_framehook_attach(c0)) {
294                 return -1;
295         }
296
297         native_rtp_bridge_framehook_detach(c1);
298         if (native_rtp_bridge_framehook_attach(c1)) {
299                 native_rtp_bridge_framehook_detach(c0);
300                 return -1;
301         }
302
303         native_type = native_rtp_bridge_get(c0->chan, c1->chan, &glue0, &glue1, &instance0, &instance1, &vinstance0, &vinstance1);
304
305         if (glue0->get_codec) {
306                 glue0->get_codec(c0->chan, cap0);
307         }
308         if (glue1->get_codec) {
309                 glue1->get_codec(c1->chan, cap1);
310         }
311
312         if (native_type == AST_RTP_GLUE_RESULT_LOCAL) {
313                 if (ast_rtp_instance_get_engine(instance0)->local_bridge) {
314                         ast_rtp_instance_get_engine(instance0)->local_bridge(instance0, instance1);
315                 }
316                 if (ast_rtp_instance_get_engine(instance1)->local_bridge) {
317                         ast_rtp_instance_get_engine(instance1)->local_bridge(instance1, instance0);
318                 }
319                 ast_rtp_instance_set_bridged(instance0, instance1);
320                 ast_rtp_instance_set_bridged(instance1, instance0);
321         } else {
322                 glue0->update_peer(c0->chan, instance1, vinstance1, tinstance1, cap1, 0);
323                 glue1->update_peer(c1->chan, instance0, vinstance0, tinstance0, cap0, 0);
324         }
325
326         return 0;
327 }
328
329 static void native_rtp_bridge_unsuspend(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
330 {
331         native_rtp_bridge_join(bridge, bridge_channel);
332 }
333
334 static void native_rtp_bridge_leave(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
335 {
336         struct ast_bridge_channel *c0 = AST_LIST_FIRST(&bridge->channels) ? AST_LIST_FIRST(&bridge->channels) : bridge_channel;
337         struct ast_bridge_channel *c1 = AST_LIST_LAST(&bridge->channels);
338         enum ast_rtp_glue_result native_type;
339         struct ast_rtp_glue *glue0, *glue1 = NULL;
340         struct ast_rtp_instance *instance0 = NULL, *instance1 = NULL, *vinstance0 = NULL, *vinstance1 = NULL;
341
342         native_rtp_bridge_framehook_detach(c0);
343         if (c1) {
344                 native_rtp_bridge_framehook_detach(c1);
345         }
346
347         native_type = native_rtp_bridge_get(c0->chan, c1 ? c1->chan : NULL, &glue0, &glue1, &instance0, &instance1, &vinstance0, &vinstance1);
348
349         if (native_type == AST_RTP_GLUE_RESULT_LOCAL) {
350                 if (ast_rtp_instance_get_engine(instance0)->local_bridge) {
351                         ast_rtp_instance_get_engine(instance0)->local_bridge(instance0, NULL);
352                 }
353                 if (instance1 && ast_rtp_instance_get_engine(instance1)->local_bridge) {
354                         ast_rtp_instance_get_engine(instance1)->local_bridge(instance1, NULL);
355                 }
356                 ast_rtp_instance_set_bridged(instance0, instance1);
357                 if (instance1) {
358                         ast_rtp_instance_set_bridged(instance1, instance0);
359                 }
360         } else {
361                 glue0->update_peer(c0->chan, NULL, NULL, NULL, NULL, 0);
362                 if (glue1) {
363                         glue1->update_peer(c1->chan, NULL, NULL, NULL, NULL, 0);
364                 }
365         }
366 }
367
368 static int native_rtp_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
369 {
370         struct ast_bridge_channel *other = ast_bridge_channel_peer(bridge_channel);
371
372         if (!other) {
373                 return -1;
374         }
375
376         /* The bridging core takes care of freeing the passed in frame. */
377         ast_bridge_channel_queue_frame(other, frame);
378
379         return 0;
380 }
381
382 static struct ast_bridge_technology native_rtp_bridge = {
383         .name = "native_rtp",
384         .capabilities = AST_BRIDGE_CAPABILITY_NATIVE,
385         .preference = AST_BRIDGE_PREFERENCE_BASE_NATIVE,
386         .join = native_rtp_bridge_join,
387         .unsuspend = native_rtp_bridge_unsuspend,
388         .leave = native_rtp_bridge_leave,
389         .suspend = native_rtp_bridge_leave,
390         .write = native_rtp_bridge_write,
391         .compatible = native_rtp_bridge_compatible,
392 };
393
394 static int unload_module(void)
395 {
396         ast_format_cap_destroy(native_rtp_bridge.format_capabilities);
397         return ast_bridge_technology_unregister(&native_rtp_bridge);
398 }
399
400 static int load_module(void)
401 {
402         if (!(native_rtp_bridge.format_capabilities = ast_format_cap_alloc())) {
403                 return AST_MODULE_LOAD_DECLINE;
404         }
405         ast_format_cap_add_all_by_type(native_rtp_bridge.format_capabilities, AST_FORMAT_TYPE_AUDIO);
406         ast_format_cap_add_all_by_type(native_rtp_bridge.format_capabilities, AST_FORMAT_TYPE_VIDEO);
407         ast_format_cap_add_all_by_type(native_rtp_bridge.format_capabilities, AST_FORMAT_TYPE_TEXT);
408
409         return ast_bridge_technology_register(&native_rtp_bridge);
410 }
411
412 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Native RTP bridging module");