src/core/sdpmsg.c

   1 /**
   2  * @file sdpmsg.c
   3  *
   4  * pidgin-sipe
   5  *
   6  * Copyright (C) 2010 Jakub Adam <jakub.adam@ktknet.cz>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <glib.h>
  28
  29 #include "sipe-backend.h"
  30 #include "sdpmsg.h"
  31 #include "sipe-utils.h"
  32
  33 static gboolean
  34 append_attribute(struct sdpmedia *media, gchar *attr)
  35 {
  36         gchar **parts = g_strsplit(attr + 2, ":", 2);
  37
  38         if(!parts[0]) {
  39                 g_strfreev(parts);
  40                 return FALSE;
  41         }
  42
  43         media->attributes = sipe_utils_nameval_add(media->attributes,
  44                                                    parts[0],
  45                                                    parts[1] ? parts[1] : "");
  46         g_strfreev(parts);
  47         return TRUE;
  48 }
  49
  50 static gboolean
  51 parse_attributes(struct sdpmsg *smsg, gchar *msg) {
  52         gchar           **lines = g_strsplit(msg, "\r\n", 0);
  53         gchar           **ptr = lines;
  54
  55         while (*ptr != NULL) {
  56                 if (g_str_has_prefix(*ptr, "o=")) {
  57                         gchar **parts = g_strsplit(*ptr + 2, " ", 6);
  58                         smsg->ip = g_strdup(parts[5]);
  59                         g_strfreev(parts);
  60                 } else if (g_str_has_prefix(*ptr, "m=")) {
  61                         gchar **parts = g_strsplit(*ptr + 2, " ", 3);
  62                         struct sdpmedia *media = g_new0(struct sdpmedia, 1);
  63
  64                         smsg->media = g_slist_append(smsg->media, media);
  65
  66                         media->name = g_strdup(parts[0]);
  67                         media->port = atoi(parts[1]);
  68
  69                         g_strfreev(parts);
  70
  71                         while (*(++ptr) && !g_str_has_prefix(*ptr, "m=")) {
  72
  73                                 if (g_str_has_prefix(*ptr, "a=")) {
  74                                         if (!append_attribute(media, *ptr)) {
  75                                                 g_strfreev(lines);
  76                                                 return FALSE;
  77                                         }
  78                                 }
  79                         }
  80                         continue;
  81                 }
  82
  83                 ++ptr;
  84         }
  85
  86         g_strfreev(lines);
  87
  88         return TRUE;
  89 }
  90
  91 static void sdpcandidate_free(struct sdpcandidate *candidate);
  92
  93 static SipeComponentType
  94 parse_component(const gchar *str)
  95 {
  96         switch (atoi(str)) {
  97                 case 1: return  SIPE_COMPONENT_RTP;
  98                 case 2: return  SIPE_COMPONENT_RTCP;
  99                 default: return SIPE_COMPONENT_NONE;
 100         }
 101 }
 102
 103 static gchar *
 104 base64_pad(const gchar* str)
 105 {
 106         size_t str_len = strlen(str);
 107         int mod = str_len % 4;
 108
 109         if (mod > 0) {
 110                 gchar *result = NULL;
 111                 int pad = 4 - mod;
 112                 gchar *ptr = result = g_malloc(str_len + pad + 1);
 113
 114                 memcpy(ptr, str, str_len);
 115                 ptr += str_len;
 116                 memset(ptr, '=', pad);
 117                 ptr += pad;
 118                 *ptr = '\0';
 119
 120                 return result;
 121         } else
 122                 return g_strdup(str);
 123 }
 124
 125 static struct sdpcandidate *
 126 parse_candidate_draft_6(gchar **tokens)
 127 {
 128         struct sdpcandidate *candidate = g_new0(struct sdpcandidate, 1);
 129
 130         candidate->username = base64_pad(tokens[0]);
 131         candidate->component = parse_component(tokens[1]);
 132         candidate->password = base64_pad(tokens[2]);
 133
 134         if (sipe_strequal(tokens[3], "UDP"))
 135                 candidate->protocol = SIPE_NETWORK_PROTOCOL_UDP;
 136         else {
 137                 // Ignore TCP candidates, at least for now...
 138                 // Also, if this is ICEv6 candidate list, candidates are dropped here
 139                 sdpcandidate_free(candidate);
 140                 return NULL;
 141         }
 142
 143         candidate->priority = atoi(tokens[4] + 2);
 144         candidate->ip = g_strdup(tokens[5]);
 145         candidate->port = atoi(tokens[6]);
 146
 147         return candidate;
 148 }
 149
 150 static struct sdpcandidate *
 151 parse_candidate_rfc_5245(gchar **tokens)
 152 {
 153         struct sdpcandidate *candidate = g_new0(struct sdpcandidate, 1);
 154
 155         candidate->foundation = g_strdup(tokens[0]);
 156         candidate->component = parse_component(tokens[1]);
 157
 158         if (sipe_strequal(tokens[2], "UDP"))
 159                 candidate->protocol = SIPE_NETWORK_PROTOCOL_UDP;
 160         else {
 161                 // Ignore TCP candidates, at least for now...
 162                 // Also, if this is ICEv6 candidate list, candidates are dropped here
 163                 sdpcandidate_free(candidate);
 164                 return NULL;
 165         }
 166
 167         candidate->priority = atoi(tokens[3]);
 168         candidate->ip = g_strdup(tokens[4]);
 169         candidate->port = atoi(tokens[5]);
 170
 171         if (sipe_strequal(tokens[7], "host"))
 172                 candidate->type = SIPE_CANDIDATE_TYPE_HOST;
 173         else if (sipe_strequal(tokens[7], "relay"))
 174                 candidate->type = SIPE_CANDIDATE_TYPE_RELAY;
 175         else if (sipe_strequal(tokens[7], "srflx"))
 176                 candidate->type = SIPE_CANDIDATE_TYPE_SRFLX;
 177         else if (sipe_strequal(tokens[7], "prflx"))
 178                 candidate->type = SIPE_CANDIDATE_TYPE_PRFLX;
 179         else {
 180                 sdpcandidate_free(candidate);
 181                 return NULL;
 182         }
 183
 184         return candidate;
 185 }
 186
 187 static GSList *
 188 parse_candidates(GSList *attrs, SipeIceVersion *ice_version)
 189 {
 190         GSList *candidates = NULL;
 191         const gchar *attr;
 192         int i = 0;
 193
 194         while ((attr = sipe_utils_nameval_find_instance(attrs, "candidate", i++))) {
 195                 gchar **tokens = g_strsplit_set(attr, " ", 0);
 196
 197                 if (sipe_strequal(tokens[6], "typ")) {
 198                         struct sdpcandidate *c = parse_candidate_rfc_5245(tokens);
 199
 200                         if (c) {
 201                                 *ice_version = SIPE_ICE_RFC_5245;
 202                                 candidates = g_slist_append(candidates, c);
 203                         }
 204                 } else {
 205                         struct sdpcandidate *c = parse_candidate_draft_6(tokens);
 206                         if (c) {
 207                                 *ice_version = SIPE_ICE_DRAFT_6;
 208                                 candidates = g_slist_append(candidates, c);
 209                         }
 210                 }
 211
 212                 g_strfreev(tokens);
 213         }
 214
 215         if (!candidates)
 216                 *ice_version = SIPE_ICE_NO_ICE;
 217
 218         if (*ice_version == SIPE_ICE_RFC_5245) {
 219                 const gchar *username = sipe_utils_nameval_find(attrs, "ice-ufrag");
 220                 const gchar *password = sipe_utils_nameval_find(attrs, "ice-pwd");
 221
 222                 if (username && password) {
 223                         GSList *i;
 224                         for (i = candidates; i; i = i->next) {
 225                                 struct sdpcandidate *c = i->data;
 226                                 c->username = g_strdup(username);
 227                                 c->password = g_strdup(password);
 228                         }
 229                 }
 230         }
 231
 232         return candidates;
 233 }
 234
 235 static GSList *
 236 create_legacy_candidates(gchar *ip, guint16 port)
 237 {
 238         struct sdpcandidate *candidate;
 239         GSList *candidates = NULL;
 240
 241         candidate = g_new0(struct sdpcandidate, 1);
 242         candidate->foundation = g_strdup("1");
 243         candidate->component = SIPE_COMPONENT_RTP;
 244         candidate->type = SIPE_CANDIDATE_TYPE_HOST;
 245         candidate->protocol = SIPE_NETWORK_PROTOCOL_UDP;
 246         candidate->ip = g_strdup(ip);
 247         candidate->port = port;
 248
 249         candidates = g_slist_append(candidates, candidate);
 250
 251         candidate = g_new0(struct sdpcandidate, 1);
 252         candidate->foundation = g_strdup("1");
 253         candidate->component = SIPE_COMPONENT_RTCP;
 254         candidate->type = SIPE_CANDIDATE_TYPE_HOST;
 255         candidate->protocol = SIPE_NETWORK_PROTOCOL_UDP;
 256         candidate->ip = g_strdup(ip);
 257         candidate->port = port + 1;
 258
 259         candidates = g_slist_append(candidates, candidate);
 260
 261         return candidates;
 262 }
 263
 264 static GSList *
 265 parse_codecs(GSList *attrs, SipeMediaType type)
 266 {
 267         int i = 0;
 268         const gchar *attr;
 269         GSList *codecs = NULL;
 270
 271         while ((attr = sipe_utils_nameval_find_instance(attrs, "rtpmap", i++))) {
 272                 struct sdpcodec *codec = g_new0(struct sdpcodec, 1);
 273                 gchar **tokens = g_strsplit_set(attr, " /", 3);
 274
 275                 int j = 0;
 276                 const gchar* params;
 277
 278                 codec->id = atoi(tokens[0]);
 279                 codec->name = g_strdup(tokens[1]);
 280                 codec->clock_rate = atoi(tokens[2]);
 281                 codec->type = type;
 282
 283                 // TODO: more secure and effective implementation
 284                 while((params = sipe_utils_nameval_find_instance(attrs, "fmtp", j++))) {
 285                         gchar **tokens = g_strsplit_set(params, " ", 0);
 286                         gchar **next = tokens + 1;
 287
 288                         if (atoi(tokens[0]) == codec->id) {
 289                                 while (*next) {
 290                                         gchar name[50];
 291                                         gchar value[50];
 292
 293                                         if (sscanf(*next, "%[a-zA-Z0-9]=%s", name, value) == 2)
 294                                                 codec->parameters = sipe_utils_nameval_add(codec->parameters, name, value);
 295
 296                                         ++next;
 297                                 }
 298                         }
 299
 300                         g_strfreev(tokens);
 301                 }
 302
 303                 codecs = g_slist_append(codecs, codec);
 304                 g_strfreev(tokens);
 305         }
 306
 307         return codecs;
 308 }
 309
 310 struct sdpmsg *
 311 sdpmsg_parse_msg(gchar *msg)
 312 {
 313         struct sdpmsg *smsg = g_new0(struct sdpmsg, 1);
 314         GSList *i;
 315
 316         if (!parse_attributes(smsg, msg)) {
 317                 sdpmsg_free(smsg);
 318                 return NULL;
 319         }
 320
 321         for (i = smsg->media; i; i = i->next) {
 322                 struct sdpmedia *media = i->data;
 323                 SipeMediaType type;
 324
 325                 media->candidates = parse_candidates(media->attributes,
 326                                                      &smsg->ice_version);
 327
 328                 if (!media->candidates && media->port != 0) {
 329                         // No a=candidate in SDP message, this seems to be MSOC 2005
 330                         media->candidates = create_legacy_candidates(smsg->ip, media->port);
 331                 }
 332
 333                 if (sipe_strequal(media->name, "audio"))
 334                         type = SIPE_MEDIA_AUDIO;
 335                 else if (sipe_strequal(media->name, "video"))
 336                         type = SIPE_MEDIA_VIDEO;
 337                 else {
 338                         // Unknown media type
 339                         sdpmsg_free(smsg);
 340                         return NULL;
 341                 }
 342
 343                 media->codecs = parse_codecs(media->attributes, type);
 344         }
 345
 346         return smsg;
 347 }
 348
 349 static gchar *
 350 codecs_to_string(GSList *codecs)
 351 {
 352         GString *result = g_string_new(NULL);
 353
 354         for (; codecs; codecs = codecs->next) {
 355                 struct sdpcodec *c = codecs->data;
 356                 GSList *params = c->parameters;
 357
 358                 g_string_append_printf(result,
 359                                        "a=rtpmap:%d %s/%d\r\n",
 360                                        c->id,
 361                                        c->name,
 362                                        c->clock_rate);
 363
 364                 if (params) {
 365                         g_string_append_printf(result, "a=fmtp:%d", c->id);
 366
 367                         for (; params; params = params->next) {
 368                                 struct sipnameval* par = params->data;
 369                                 g_string_append_printf(result, " %s=%s",
 370                                                        par->name, par->value);
 371                         }
 372
 373                         g_string_append(result, "\r\n");
 374                 }
 375         }
 376
 377         return g_string_free(result, FALSE);
 378 }
 379
 380 static gchar *
 381 codec_ids_to_string(GSList *codecs)
 382 {
 383         GString *result = g_string_new(NULL);
 384
 385         for (; codecs; codecs = codecs->next) {
 386                 struct sdpcodec *c = codecs->data;
 387                 g_string_append_printf(result, " %d", c->id);
 388         }
 389
 390         return g_string_free(result, FALSE);
 391 }
 392
 393 static gchar *
 394 base64_unpad(const gchar *str)
 395 {
 396         gchar *result = g_strdup(str);
 397         gchar *ptr;
 398
 399         for (ptr = result + strlen(result); ptr != result; --ptr) {
 400                 if (*(ptr - 1) != '=') {
 401                         *ptr = '\0';
 402                         break;
 403                 }
 404         }
 405
 406         return result;
 407 }
 408
 409 static gint
 410 candidate_sort_cb(struct sdpcandidate *c1, struct sdpcandidate *c2)
 411 {
 412         int cmp = sipe_strcompare(c1->foundation, c2->foundation);
 413         if (cmp == 0) {
 414                 cmp = sipe_strcompare(c1->username, c2->username);
 415                 if (cmp == 0)
 416                         cmp = c1->component - c2->component;
 417         }
 418
 419         return cmp;
 420 }
 421
 422 static gchar *
 423 candidates_to_string(GSList *candidates, SipeIceVersion ice_version)
 424 {
 425         GString *result = g_string_new("");
 426         GSList *i;
 427
 428         candidates = g_slist_copy(candidates);
 429         candidates = g_slist_sort(candidates, (GCompareFunc)candidate_sort_cb);
 430
 431         for (i = candidates; i; i = i->next) {
 432                 struct sdpcandidate *c = i->data;
 433                 const gchar *protocol;
 434                 const gchar *type;
 435                 gchar *related = NULL;
 436
 437                 switch (c->protocol) {
 438                         case SIPE_NETWORK_PROTOCOL_TCP:
 439                                 protocol = "TCP";
 440                                 break;
 441                         case SIPE_NETWORK_PROTOCOL_UDP:
 442                                 protocol = "UDP";
 443                                 break;
 444                 }
 445
 446                 if (ice_version == SIPE_ICE_RFC_5245) {
 447
 448                         switch (c->type) {
 449                                 case SIPE_CANDIDATE_TYPE_HOST:
 450                                         type = "host";
 451                                         break;
 452                                 case SIPE_CANDIDATE_TYPE_RELAY:
 453                                         type = "relay";
 454                                         related = g_strdup_printf("raddr %s rport %d ",
 455                                                                   c->ip,
 456                                                                   c->port);
 457                                         break;
 458                                 case SIPE_CANDIDATE_TYPE_SRFLX:
 459                                         type = "srflx";
 460                                         related = g_strdup_printf("raddr %s rport %d",
 461                                                                   c->base_ip,
 462                                                                   c->base_port);
 463                                         break;
 464                                 case SIPE_CANDIDATE_TYPE_PRFLX:
 465                                         type = "prflx";
 466                                         break;
 467                                 default:
 468                                         // TODO: error unknown/unsupported type
 469                                         break;
 470                         }
 471
 472                         g_string_append_printf(result,
 473                                                "a=candidate:%s %u %s %u %s %d typ %s %s\r\n",
 474                                                c->foundation,
 475                                                c->component,
 476                                                protocol,
 477                                                c->priority,
 478                                                c->ip,
 479                                                c->port,
 480                                                type,
 481                                                related ? related : "");
 482                         g_free(related);
 483
 484                 } else if (ice_version == SIPE_ICE_DRAFT_6) {
 485                         gchar *username = base64_unpad(c->username);
 486                         gchar *password = base64_unpad(c->password);
 487
 488                         g_string_append_printf(result,
 489                                                "a=candidate:%s %u %s %s 0.%u %s %d\r\n",
 490                                                username,
 491                                                c->component,
 492                                                password,
 493                                                protocol,
 494                                                c->priority,
 495                                                c->ip,
 496                                                c->port);
 497
 498                         g_free(username);
 499                         g_free(password);
 500                 }
 501         }
 502
 503         g_slist_free(candidates);
 504
 505         return g_string_free(result, FALSE);
 506 }
 507
 508 static gchar *
 509 remote_candidates_to_string(GSList *candidates, SipeIceVersion ice_version)
 510 {
 511         GString *result = g_string_new("");
 512
 513         candidates = g_slist_copy(candidates);
 514         candidates = g_slist_sort(candidates, (GCompareFunc)candidate_sort_cb);
 515
 516         if (candidates) {
 517                 if (ice_version == SIPE_ICE_RFC_5245) {
 518                         GSList *i;
 519                         g_string_append(result, "a=remote-candidates:");
 520
 521                         for (i = candidates; i; i = i->next) {
 522                                 struct sdpcandidate *c = i->data;
 523                                 g_string_append_printf(result, "%u %s %u ",
 524                                                        c->component, c->ip, c->port);
 525                         }
 526
 527                         g_string_append(result, "\r\n");
 528                 } else if (ice_version == SIPE_ICE_DRAFT_6) {
 529                         struct sdpcandidate *c = candidates->data;
 530                         g_string_append_printf(result, "a=remote-candidate:%s\r\n",
 531                                                c->username);
 532                 }
 533         }
 534
 535         g_slist_free(candidates);
 536
 537         return g_string_free(result, FALSE);
 538 }
 539
 540 static gchar *
 541 attributes_to_string(GSList *attributes)
 542 {
 543         GString *result = g_string_new("");
 544
 545         for (; attributes; attributes = attributes->next) {
 546                 struct sipnameval *a = attributes->data;
 547                 g_string_append_printf(result, "a=%s", a->name);
 548                 if (!sipe_strequal(a->value, ""))
 549                         g_string_append_printf(result, ":%s", a->value);
 550                 g_string_append(result, "\r\n");
 551         }
 552
 553         return g_string_free(result, FALSE);
 554 }
 555
 556 static gchar *
 557 media_to_string(const struct sdpmedia *media, SipeIceVersion ice_version)
 558 {
 559         gchar *media_str;
 560
 561         gchar *codecs_str = codecs_to_string(media->codecs);
 562         gchar *codec_ids_str = codec_ids_to_string(media->codecs);
 563
 564         gchar *candidates_str = candidates_to_string(media->candidates, ice_version);
 565         gchar *remote_candidates_str = remote_candidates_to_string(media->remote_candidates,
 566                                                                    ice_version);
 567
 568         gchar *attributes_str = attributes_to_string(media->attributes);
 569         gchar *credentials = NULL;
 570
 571         if (ice_version == SIPE_ICE_RFC_5245 && media->candidates) {
 572                 struct sdpcandidate *c = media->candidates->data;
 573
 574                 credentials = g_strdup_printf("a=ice-ufrag:%s\r\n"
 575                                               "a=ice-pwd:%s\r\n",
 576                                               c->username,
 577                                               c->password);
 578         }
 579
 580         media_str = g_strdup_printf("m=%s %d RTP/AVP%s\r\n"
 581                                     "%s"
 582                                     "%s"
 583                                     "%s"
 584                                     "%s"
 585                                     "%s",
 586                                     media->name, media->port, codec_ids_str,
 587                                     candidates_str,
 588                                     remote_candidates_str,
 589                                     codecs_str,
 590                                     attributes_str,
 591                                     credentials ? credentials : "");
 592
 593         g_free(codecs_str);
 594         g_free(codec_ids_str);
 595         g_free(candidates_str);
 596         g_free(remote_candidates_str);
 597         g_free(attributes_str);
 598         g_free(credentials);
 599
 600         return media_str;
 601 }
 602
 603 gchar *
 604 sdpmsg_to_string(const struct sdpmsg *msg)
 605 {
 606         GString *body = g_string_new(NULL);
 607         GSList *i;
 608
 609         g_string_append_printf(
 610                 body,
 611                 "v=0\r\n"
 612                 "o=- 0 0 IN IP4 %s\r\n"
 613                 "s=session\r\n"
 614                 "c=IN IP4 %s\r\n"
 615                 "b=CT:99980\r\n"
 616                 "t=0 0\r\n",
 617                 msg->ip, msg->ip);
 618
 619
 620         for (i = msg->media; i; i = i->next) {
 621                 gchar *media_str = media_to_string(i->data, msg->ice_version);
 622                 g_string_append(body, media_str);
 623                 g_free(media_str);
 624         }
 625
 626         return g_string_free(body, FALSE);
 627 }
 628
 629 static void
 630 sdpcandidate_free(struct sdpcandidate *candidate)
 631 {
 632         if (candidate) {
 633                 g_free(candidate->foundation);
 634                 g_free(candidate->ip);
 635                 g_free(candidate->base_ip);
 636                 g_free(candidate->username);
 637                 g_free(candidate->password);
 638                 g_free(candidate);
 639         }
 640 }
 641
 642 static void
 643 sdpcodec_free(struct sdpcodec *codec)
 644 {
 645         if (codec) {
 646                 g_free(codec->name);
 647                 sipe_utils_nameval_free(codec->parameters);
 648                 g_free(codec);
 649         }
 650 }
 651
 652 static void
 653 sdpmedia_free(struct sdpmedia *media)
 654 {
 655         if (media) {
 656                 GSList *item;
 657
 658                 g_free(media->name);
 659                 g_free(media->ip);
 660
 661                 sipe_utils_nameval_free(media->attributes);
 662
 663                 for (item = media->candidates; item; item = item->next)
 664                         sdpcandidate_free(item->data);
 665                 g_slist_free(media->candidates);
 666
 667                 for (item = media->codecs; item; item = item->next)
 668                         sdpcodec_free(item->data);
 669                 g_slist_free(media->codecs);
 670
 671                 for (item = media->remote_candidates; item; item = item->next)
 672                         sdpcandidate_free(item->data);
 673                 g_slist_free(media->remote_candidates);
 674
 675                 g_free(media);
 676         }
 677 }
 678
 679 void
 680 sdpmsg_free(struct sdpmsg *msg)
 681 {
 682         if (msg) {
 683                 GSList *item;
 684
 685                 g_free(msg->ip);
 686                 for (item = msg->media; item; item = item->next)
 687                         sdpmedia_free(item->data);
 688                 g_slist_free(msg->media);
 689                 g_free(msg);
 690         }
 691 }
 692
 693 /*
 694   Local Variables:
 695   mode: c
 696   c-file-style: "bsd"
 697   indent-tabs-mode: t
 698   tab-width: 8
 699   End:
 700 */