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 /*
 262  * BUGBUG The RTP native bridge technology should use tech_pvt not bridge_pvt.
 263  *
 264  * This technology needs to be reworked to not change the
 265  * tech_pvt of channels other than the one that is currently
 266  * entering/leaving before it can actually use the correct
 267  * pointer.
 268  */
 269         bridge_channel->bridge_pvt = data;
 270
 271         return 0;
 272 }
 273
 274 /*! \brief Helper function which removes frame hook from bridge channel */
 275 static void native_rtp_bridge_framehook_detach(struct ast_bridge_channel *bridge_channel)
 276 {
 277         RAII_VAR(struct native_rtp_bridge_data *, data, bridge_channel->bridge_pvt, ao2_cleanup);
 278
 279         if (!data) {
 280                 return;
 281         }
 282
 283         ast_channel_lock(bridge_channel->chan);
 284         ast_framehook_detach(bridge_channel->chan, data->id);
 285         ast_channel_unlock(bridge_channel->chan);
 286         bridge_channel->bridge_pvt = NULL;
 287 }
 288
 289 static int native_rtp_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
 290 {
 291         struct ast_bridge_channel *c0 = AST_LIST_FIRST(&bridge->channels);
 292         struct ast_bridge_channel *c1 = AST_LIST_LAST(&bridge->channels);
 293         enum ast_rtp_glue_result native_type;
 294         struct ast_rtp_glue *glue0, *glue1;
 295         struct ast_rtp_instance *instance0 = NULL, *instance1 = NULL, *vinstance0 = NULL;
 296         struct ast_rtp_instance *vinstance1 = NULL, *tinstance0 = NULL, *tinstance1 = NULL;
 297         RAII_VAR(struct ast_format_cap *, cap0, ast_format_cap_alloc_nolock(), ast_format_cap_destroy);
 298         RAII_VAR(struct ast_format_cap *, cap1, ast_format_cap_alloc_nolock(), ast_format_cap_destroy);
 299
 300         native_rtp_bridge_framehook_detach(c0);
 301         if (native_rtp_bridge_framehook_attach(c0)) {
 302                 return -1;
 303         }
 304
 305         native_rtp_bridge_framehook_detach(c1);
 306         if (native_rtp_bridge_framehook_attach(c1)) {
 307                 native_rtp_bridge_framehook_detach(c0);
 308                 return -1;
 309         }
 310
 311         native_type = native_rtp_bridge_get(c0->chan, c1->chan, &glue0, &glue1, &instance0, &instance1, &vinstance0, &vinstance1);
 312
 313         if (glue0->get_codec) {
 314                 glue0->get_codec(c0->chan, cap0);
 315         }
 316         if (glue1->get_codec) {
 317                 glue1->get_codec(c1->chan, cap1);
 318         }
 319
 320         if (native_type == AST_RTP_GLUE_RESULT_LOCAL) {
 321                 if (ast_rtp_instance_get_engine(instance0)->local_bridge) {
 322                         ast_rtp_instance_get_engine(instance0)->local_bridge(instance0, instance1);
 323                 }
 324                 if (ast_rtp_instance_get_engine(instance1)->local_bridge) {
 325                         ast_rtp_instance_get_engine(instance1)->local_bridge(instance1, instance0);
 326                 }
 327                 ast_rtp_instance_set_bridged(instance0, instance1);
 328                 ast_rtp_instance_set_bridged(instance1, instance0);
 329         } else {
 330                 glue0->update_peer(c0->chan, instance1, vinstance1, tinstance1, cap1, 0);
 331                 glue1->update_peer(c1->chan, instance0, vinstance0, tinstance0, cap0, 0);
 332         }
 333
 334         return 0;
 335 }
 336
 337 static void native_rtp_bridge_unsuspend(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
 338 {
 339         native_rtp_bridge_join(bridge, bridge_channel);
 340 }
 341
 342 static void native_rtp_bridge_leave(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
 343 {
 344         struct ast_bridge_channel *c0 = AST_LIST_FIRST(&bridge->channels) ? AST_LIST_FIRST(&bridge->channels) : bridge_channel;
 345         struct ast_bridge_channel *c1 = AST_LIST_LAST(&bridge->channels);
 346         enum ast_rtp_glue_result native_type;
 347         struct ast_rtp_glue *glue0, *glue1 = NULL;
 348         struct ast_rtp_instance *instance0 = NULL, *instance1 = NULL, *vinstance0 = NULL, *vinstance1 = NULL;
 349
 350         native_rtp_bridge_framehook_detach(c0);
 351         if (c1) {
 352                 native_rtp_bridge_framehook_detach(c1);
 353         }
 354
 355         native_type = native_rtp_bridge_get(c0->chan, c1 ? c1->chan : NULL, &glue0, &glue1, &instance0, &instance1, &vinstance0, &vinstance1);
 356
 357         if (native_type == AST_RTP_GLUE_RESULT_LOCAL) {
 358                 if (ast_rtp_instance_get_engine(instance0)->local_bridge) {
 359                         ast_rtp_instance_get_engine(instance0)->local_bridge(instance0, NULL);
 360                 }
 361                 if (instance1 && ast_rtp_instance_get_engine(instance1)->local_bridge) {
 362                         ast_rtp_instance_get_engine(instance1)->local_bridge(instance1, NULL);
 363                 }
 364                 ast_rtp_instance_set_bridged(instance0, instance1);
 365                 if (instance1) {
 366                         ast_rtp_instance_set_bridged(instance1, instance0);
 367                 }
 368         } else {
 369                 glue0->update_peer(c0->chan, NULL, NULL, NULL, NULL, 0);
 370                 if (glue1) {
 371                         glue1->update_peer(c1->chan, NULL, NULL, NULL, NULL, 0);
 372                 }
 373         }
 374 }
 375
 376 static int native_rtp_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
 377 {
 378         struct ast_bridge_channel *other = ast_bridge_channel_peer(bridge_channel);
 379
 380         if (!other) {
 381                 return -1;
 382         }
 383
 384         /* The bridging core takes care of freeing the passed in frame. */
 385         ast_bridge_channel_queue_frame(other, frame);
 386
 387         return 0;
 388 }
 389
 390 static struct ast_bridge_technology native_rtp_bridge = {
 391         .name = "native_rtp",
 392         .capabilities = AST_BRIDGE_CAPABILITY_NATIVE,
 393         .preference = AST_BRIDGE_PREFERENCE_BASE_NATIVE,
 394         .join = native_rtp_bridge_join,
 395         .unsuspend = native_rtp_bridge_unsuspend,
 396         .leave = native_rtp_bridge_leave,
 397         .suspend = native_rtp_bridge_leave,
 398         .write = native_rtp_bridge_write,
 399         .compatible = native_rtp_bridge_compatible,
 400 };
 401
 402 static int unload_module(void)
 403 {
 404         ast_format_cap_destroy(native_rtp_bridge.format_capabilities);
 405         return ast_bridge_technology_unregister(&native_rtp_bridge);
 406 }
 407
 408 static int load_module(void)
 409 {
 410         if (!(native_rtp_bridge.format_capabilities = ast_format_cap_alloc())) {
 411                 return AST_MODULE_LOAD_DECLINE;
 412         }
 413         ast_format_cap_add_all_by_type(native_rtp_bridge.format_capabilities, AST_FORMAT_TYPE_AUDIO);
 414         ast_format_cap_add_all_by_type(native_rtp_bridge.format_capabilities, AST_FORMAT_TYPE_VIDEO);
 415         ast_format_cap_add_all_by_type(native_rtp_bridge.format_capabilities, AST_FORMAT_TYPE_TEXT);
 416
 417         return ast_bridge_technology_register(&native_rtp_bridge);
 418 }
 419
 420 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Native RTP bridging module");