packet-sdp.c

   1 /* packet-sdp.c
   2  * Routines for SDP packet disassembly (RFC 2327)
   3  *
   4  * Jason Lango <jal@netapp.com>
   5  * Liberally copied from packet-http.c, by Guy Harris <guy@alum.mit.edu>
   6  *
   7  * $Id: packet-sdp.c,v 1.30 2002/04/14 23:22:22 guy Exp $
   8  *
   9  * Ethereal - Network traffic analyzer
  10  * By Gerald Combs <gerald@ethereal.com>
  11  * Copyright 1998 Gerald Combs
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version 2
  16  * of the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  26  */
  27
  28 #include "config.h"
  29
  30 #ifdef HAVE_SYS_TYPES_H
  31 #include <sys/types.h>
  32 #endif
  33
  34 #include <string.h>
  35 #include <ctype.h>
  36
  37 #include <glib.h>
  38 #include <epan/packet.h>
  39 #include <epan/strutil.h>
  40
  41 static int proto_sdp = -1;
  42
  43 /* Top level fields */
  44 static int hf_protocol_version = -1;
  45 static int hf_owner = -1;
  46 static int hf_session_name = -1;
  47 static int hf_session_info = -1;
  48 static int hf_uri = -1;
  49 static int hf_email = -1;
  50 static int hf_phone = -1;
  51 static int hf_connection_info = -1;
  52 static int hf_bandwidth = -1;
  53 static int hf_timezone = -1;
  54 static int hf_encryption_key = -1;
  55 static int hf_session_attribute = -1;
  56 static int hf_media_attribute = -1;
  57 static int hf_time = -1;
  58 static int hf_repeat_time = -1;
  59 static int hf_media = -1;
  60 static int hf_media_title = -1;
  61 static int hf_unknown = -1;
  62 static int hf_misplaced = -1;
  63 static int hf_invalid = -1;
  64
  65 /* hf_owner subfields*/
  66 static int hf_owner_username = -1;
  67 static int hf_owner_sessionid = -1;
  68 static int hf_owner_version = -1;
  69 static int hf_owner_network_type = -1;
  70 static int hf_owner_address_type = -1;
  71 static int hf_owner_address = -1;
  72
  73 /* hf_connection_info subfields */
  74 static int hf_connection_info_network_type = -1;
  75 static int hf_connection_info_address_type = -1;
  76 static int hf_connection_info_connection_address = -1;
  77 static int hf_connection_info_ttl = -1;
  78 static int hf_connection_info_num_addr = -1;
  79
  80 /* hf_bandwidth subfields */
  81 static int hf_bandwidth_modifier = -1;
  82 static int hf_bandwidth_value = -1;
  83
  84 /* hf_time subfields */
  85 static int hf_time_start = -1;
  86 static int hf_time_stop = -1;
  87
  88 /* hf_repeat_time subfield */
  89 static int hf_repeat_time_interval = -1;
  90 static int hf_repeat_time_duration = -1;
  91 static int hf_repeat_time_offset = -1;
  92
  93 /* hf_timezone subfields */
  94 static int hf_timezone_time = -1;
  95 static int hf_timezone_offset = -1;
  96
  97 /* hf_encryption_key subfields */
  98 static int hf_encryption_key_type = -1;
  99 static int hf_encryption_key_data = -1;
 100
 101 /* hf_session_attribute subfields */
 102 static int hf_session_attribute_field = -1;
 103 static int hf_session_attribute_value = -1;
 104
 105 /* hf_media subfields */
 106 static int hf_media_media = -1;
 107 static int hf_media_port = -1;
 108 static int hf_media_portcount = -1;
 109 static int hf_media_proto = -1;
 110 static int hf_media_format = -1;
 111
 112 /* hf_session_attribute subfields */
 113 static int hf_media_attribute_field = -1;
 114 static int hf_media_attribute_value = -1;
 115
 116 /* trees */
 117 static int ett_sdp = -1;
 118 static int ett_sdp_owner = -1;
 119 static int ett_sdp_connection_info = -1;
 120 static int ett_sdp_bandwidth = -1;
 121 static int ett_sdp_time = -1;
 122 static int ett_sdp_repeat_time = -1;
 123 static int ett_sdp_timezone = -1;
 124 static int ett_sdp_encryption_key = -1;
 125 static int ett_sdp_session_attribute = -1;
 126 static int ett_sdp_media = -1;
 127 static int ett_sdp_media_attribute = -1;
 128
 129 /* static functions */
 130
 131 static void call_sdp_subdissector(tvbuff_t *tvb, int hf, proto_tree* ti);
 132
 133 /* Subdissector functions */
 134 static void dissect_sdp_owner(tvbuff_t *tvb, proto_item* ti);
 135 static void dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti);
 136 static void dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti);
 137 static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti);
 138 static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti);
 139 static void dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti);
 140 static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti);
 141 static void dissect_sdp_session_attribute(tvbuff_t *tvb, proto_item *ti);
 142 static void dissect_sdp_media(tvbuff_t *tvb, proto_item *ti);
 143 static void dissect_sdp_media_attribute(tvbuff_t *tvb, proto_item *ti);
 144
 145 static void
 146 dissect_sdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 147 {
 148         proto_tree      *sdp_tree;
 149         proto_item      *ti, *sub_ti;
 150         gint            offset = 0;
 151         gint            next_offset;
 152         int             linelen;
 153         u_char          section;
 154         u_char          type;
 155         u_char          delim;
 156         int             datalen;
 157         int             tokenoffset;
 158         int             hf = -1;
 159         char            *string;
 160
 161         /*
 162          * As RFC 2327 says, "SDP is purely a format for session
 163          * description - it does not incorporate a transport protocol,
 164          * and is intended to use different transport protocols as
 165          * appropriate including the Session Announcement Protocol,
 166          * Session Initiation Protocol, Real-Time Streaming Protocol,
 167          * electronic mail using the MIME extensions, and the
 168          * Hypertext Transport Protocol."
 169          *
 170          * We therefore don't set the protocol or info columns;
 171          * instead, we append to them, so that we don't erase
 172          * what the protocol inside which the SDP stuff resides
 173          * put there.
 174          */
 175         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 176                 col_append_str(pinfo->cinfo, COL_PROTOCOL, "/SDP");
 177
 178         if (check_col(pinfo->cinfo, COL_INFO)) {
 179                 /* XXX: Needs description. */
 180                 col_append_str(pinfo->cinfo, COL_INFO, ", with session description");
 181         }
 182
 183         if (!tree)
 184                 return;
 185
 186         ti = proto_tree_add_item(tree, proto_sdp, tvb, offset, -1, FALSE);
 187         sdp_tree = proto_item_add_subtree(ti, ett_sdp);
 188
 189         /*
 190          * Show the SDP message a line at a time.
 191          */
 192         section = 0;
 193         while (tvb_offset_exists(tvb, offset)) {
 194                 /*
 195                  * Find the end of the line.
 196                  */
 197                 linelen = tvb_find_line_end_unquoted(tvb, offset, -1,
 198                     &next_offset);
 199
 200                 /*
 201                  * Line must contain at least e.g. "v=".
 202                  */
 203                 if (linelen < 2)
 204                         break;
 205
 206                 type = tvb_get_guint8(tvb,offset);
 207                 delim = tvb_get_guint8(tvb,offset + 1);
 208                 if (delim != '=') {
 209                         proto_tree_add_item(sdp_tree,hf_invalid,tvb, offset,
 210                                               linelen, FALSE);
 211                         offset = next_offset;
 212                         continue;
 213                 }
 214
 215                 /*
 216                  * Attributes.
 217                  */
 218                 switch (type) {
 219                 case 'v':
 220                         hf = hf_protocol_version;
 221                         section = 'v';
 222                         break;
 223                 case 'o':
 224                         hf = hf_owner;
 225                         break;
 226                 case 's':
 227                         hf = hf_session_name;
 228                         break;
 229                 case 'i':
 230                         if (section == 'v'){
 231                                 hf = hf_session_info;
 232                         }
 233                         else if (section == 'm'){
 234                                 hf = hf_media_title;
 235                         }
 236                         else{
 237                                 hf = hf_misplaced;
 238                         }
 239                         break;
 240                 case 'u':
 241                         hf = hf_uri;
 242                         break;
 243                 case 'e':
 244                         hf = hf_email;
 245                         break;
 246                 case 'p':
 247                         hf = hf_phone;
 248                         break;
 249                 case 'c':
 250                         hf = hf_connection_info;
 251                         break;
 252                 case 'b':
 253                         hf = hf_bandwidth;
 254                         break;
 255                 case 't':
 256                         hf = hf_time;
 257                         section = 't';
 258                         break;
 259                 case 'r':
 260                         hf = hf_repeat_time;
 261                         break;
 262                 case 'm':
 263                         hf = hf_media;
 264                         section = 'm';
 265                         break;
 266                 case 'k':
 267                         hf = hf_encryption_key;
 268                         break;
 269                 case 'a':
 270                         if (section == 'v'){
 271                                 hf = hf_session_attribute;
 272                         }
 273                         else if (section == 'm'){
 274                                 hf = hf_media_attribute;
 275                         }
 276                         else{
 277                                 hf = hf_misplaced;
 278                         }
 279                         break;
 280                 case 'z':
 281                         hf = hf_timezone;
 282                         break;
 283                 default:
 284                         hf = hf_unknown;
 285                         break;
 286                 }
 287                 tokenoffset = 2;
 288                 if( hf == hf_unknown || hf == hf_misplaced )
 289                   tokenoffset = 0;
 290                 string = g_malloc(linelen - tokenoffset + 1);
 291                 CLEANUP_PUSH(g_free, string);
 292                 tvb_memcpy(tvb, (guint8 *)string, offset + tokenoffset,
 293                     linelen - tokenoffset);
 294                 string[linelen - tokenoffset] = '\0';
 295                 sub_ti = proto_tree_add_string_format(sdp_tree,hf,tvb, offset,
 296                                                linelen, string,
 297                                                "%s: %s",
 298                                                proto_registrar_get_name(hf),
 299                                                format_text(string,
 300                                                  linelen - tokenoffset));
 301                 CLEANUP_CALL_AND_POP;
 302                 call_sdp_subdissector(tvb_new_subset(tvb,offset+tokenoffset,
 303                                                      linelen-tokenoffset,-1),
 304                                       hf,sub_ti);
 305                 offset = next_offset;
 306         }
 307
 308         datalen = tvb_length_remaining(tvb, offset);
 309         if (datalen > 0) {
 310                 proto_tree_add_text(sdp_tree, tvb, offset, datalen,
 311                     "Data (%d bytes)", datalen);
 312         }
 313 }
 314
 315 static void
 316 call_sdp_subdissector(tvbuff_t *tvb, int hf, proto_tree* ti){
 317   if(hf == hf_owner){
 318     dissect_sdp_owner(tvb,ti);
 319   } else if ( hf == hf_connection_info) {
 320     dissect_sdp_connection_info(tvb,ti);
 321   } else if ( hf == hf_bandwidth) {
 322     dissect_sdp_bandwidth(tvb,ti);
 323   } else if ( hf == hf_time) {
 324     dissect_sdp_time(tvb,ti);
 325   } else if ( hf == hf_repeat_time ){
 326     dissect_sdp_repeat_time(tvb,ti);
 327   } else if ( hf == hf_timezone ) {
 328     dissect_sdp_timezone(tvb,ti);
 329   } else if ( hf == hf_encryption_key ) {
 330     dissect_sdp_encryption_key(tvb,ti);
 331   } else if ( hf == hf_session_attribute ){
 332     dissect_sdp_session_attribute(tvb,ti);
 333   } else if ( hf == hf_media ) {
 334     dissect_sdp_media(tvb,ti);
 335   } else if ( hf == hf_media_attribute ){
 336     dissect_sdp_media_attribute(tvb,ti);
 337   }
 338 }
 339
 340 static void
 341 dissect_sdp_owner(tvbuff_t *tvb, proto_item *ti){
 342   proto_tree *sdp_owner_tree;
 343   gint offset,next_offset,tokenlen;
 344
 345   offset = 0;
 346   next_offset = 0;
 347   tokenlen = 0;
 348
 349   sdp_owner_tree = proto_item_add_subtree(ti,ett_sdp_owner);
 350
 351   /* Find the username */
 352   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 353   if( next_offset == -1 )
 354     return;
 355   tokenlen = next_offset - offset;
 356
 357   proto_tree_add_item(sdp_owner_tree,hf_owner_username,tvb, offset,tokenlen,
 358                       FALSE);
 359   offset = next_offset  + 1;
 360
 361   /* Find the session id */
 362   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 363   if( next_offset == -1 )
 364     return;
 365   tokenlen = next_offset - offset;
 366
 367   proto_tree_add_item(sdp_owner_tree,hf_owner_sessionid, tvb,
 368                       offset,tokenlen,FALSE);
 369   offset = next_offset + 1;
 370
 371   /* Find the version */
 372   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 373   if( next_offset == -1 )
 374     return;
 375   tokenlen = next_offset - offset;
 376
 377   proto_tree_add_item(sdp_owner_tree,hf_owner_version, tvb,
 378                       offset,tokenlen,FALSE);
 379   offset = next_offset + 1;
 380
 381   /* Find the network type */
 382   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 383   if( next_offset == -1 )
 384     return;
 385   tokenlen = next_offset - offset;
 386
 387   proto_tree_add_item(sdp_owner_tree,hf_owner_network_type, tvb,
 388                       offset,tokenlen,FALSE);
 389   offset = next_offset + 1;
 390
 391   /* Find the address type */
 392   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 393   if( next_offset == -1 )
 394     return;
 395   tokenlen = next_offset - offset;
 396
 397   proto_tree_add_item(sdp_owner_tree,hf_owner_address_type, tvb,
 398                       offset,tokenlen,FALSE);
 399   offset = next_offset + 1;
 400
 401   /* Find the address */
 402   proto_tree_add_item(sdp_owner_tree,hf_owner_address, tvb, offset, -1, FALSE);
 403 }
 404
 405 static void
 406 dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti){
 407   proto_tree *sdp_connection_info_tree;
 408   gint offset,next_offset,tokenlen;
 409
 410   offset = 0;
 411   next_offset = 0;
 412   tokenlen = 0;
 413
 414   sdp_connection_info_tree = proto_item_add_subtree(ti,
 415                                                     ett_sdp_connection_info);
 416
 417   /* Find the network type */
 418   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 419   if( next_offset == -1 )
 420     return;
 421   tokenlen = next_offset - offset;
 422
 423   proto_tree_add_item(sdp_connection_info_tree,
 424                       hf_connection_info_network_type,tvb,
 425                       offset,tokenlen,FALSE);
 426   offset = next_offset + 1;
 427
 428   /* Find the address type */
 429   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 430   if( next_offset == -1 )
 431     return;
 432   tokenlen = next_offset - offset;
 433
 434   proto_tree_add_item(sdp_connection_info_tree,
 435                       hf_connection_info_address_type,tvb,
 436                       offset,tokenlen,FALSE);
 437   offset = next_offset + 1;
 438
 439   /* Find the connection address */
 440   next_offset = tvb_find_guint8(tvb,offset,-1,'/');
 441   if( next_offset == -1){
 442     tokenlen = -1;      /* end of tvbuff */
 443   } else {
 444     tokenlen = next_offset - offset;
 445   }
 446   proto_tree_add_item(sdp_connection_info_tree,
 447                       hf_connection_info_connection_address, tvb,
 448                       offset,tokenlen,FALSE);
 449   if(next_offset != -1){
 450     offset = next_offset + 1;
 451     next_offset = tvb_find_guint8(tvb,offset,-1,'/');
 452     if( next_offset == -1){
 453       tokenlen = -1;    /* end of tvbuff */
 454     } else {
 455       tokenlen = next_offset - offset;
 456     }
 457     proto_tree_add_item(sdp_connection_info_tree,
 458                         hf_connection_info_ttl,tvb,offset,tokenlen,FALSE);
 459     if(next_offset != -1){
 460       offset = next_offset + 1;
 461       proto_tree_add_item(sdp_connection_info_tree,
 462                           hf_connection_info_num_addr, tvb,
 463                           offset, -1, FALSE);
 464     }
 465   }
 466 }
 467
 468 static void
 469 dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti){
 470   proto_tree * sdp_bandwidth_tree;
 471   gint offset, next_offset, tokenlen;
 472
 473   offset = 0;
 474   next_offset = 0;
 475   tokenlen = 0;
 476
 477   sdp_bandwidth_tree = proto_item_add_subtree(ti,ett_sdp_bandwidth);
 478
 479   /* find the modifier */
 480   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 481
 482   if( next_offset == -1)
 483     return;
 484
 485   tokenlen = next_offset - offset;
 486
 487   proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_modifier,
 488                       tvb, offset, tokenlen, FALSE);
 489
 490   offset = next_offset + 1;
 491
 492   proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_value,
 493                       tvb, offset, -1, FALSE);
 494
 495 }
 496
 497 static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti){
 498   proto_tree *sdp_time_tree;
 499   gint offset,next_offset, tokenlen;
 500
 501   offset = 0;
 502   next_offset = 0;
 503   tokenlen = 0;
 504
 505   sdp_time_tree = proto_item_add_subtree(ti,ett_sdp_time);
 506
 507   /* get start time */
 508   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 509   if( next_offset == -1 )
 510     return;
 511
 512   tokenlen = next_offset - offset;
 513   proto_tree_add_item(sdp_time_tree, hf_time_start, tvb,
 514                       offset, tokenlen, FALSE);
 515
 516   /* get stop time */
 517   offset = next_offset + 1;
 518   proto_tree_add_item(sdp_time_tree,hf_time_start, tvb,
 519                       offset, -1, FALSE);
 520 }
 521
 522 static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti){
 523   proto_tree *sdp_repeat_time_tree;
 524   gint offset,next_offset, tokenlen;
 525
 526   offset = 0;
 527   next_offset = 0;
 528   tokenlen = 0;
 529
 530   sdp_repeat_time_tree = proto_item_add_subtree(ti,ett_sdp_time);
 531
 532   /* get interval */
 533   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 534   if( next_offset == -1 )
 535     return;
 536
 537   tokenlen = next_offset - offset;
 538   proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_interval, tvb,
 539                       offset, tokenlen, FALSE);
 540
 541   /* get duration */
 542   offset = next_offset + 1;
 543   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 544   if( next_offset == -1 )
 545     return;
 546
 547   tokenlen = next_offset - offset;
 548   proto_tree_add_item(sdp_repeat_time_tree,hf_repeat_time_duration, tvb,
 549                       offset, tokenlen, FALSE);
 550
 551   /* get offsets */
 552   do{
 553     offset = next_offset +1;
 554     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 555     if(next_offset != -1){
 556       tokenlen = next_offset - offset;
 557     } else {
 558       tokenlen = -1;    /* end of tvbuff */
 559     }
 560     proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_offset,
 561                         tvb, offset, tokenlen, FALSE);
 562   } while( next_offset != -1 );
 563
 564 }
 565 static void
 566 dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti){
 567   proto_tree* sdp_timezone_tree;
 568   gint offset, next_offset, tokenlen;
 569   offset = 0;
 570   next_offset = 0;
 571   tokenlen = 0;
 572
 573   sdp_timezone_tree = proto_item_add_subtree(ti,ett_sdp_timezone);
 574
 575   do{
 576     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 577     if(next_offset == -1)
 578       break;
 579     tokenlen = next_offset - offset;
 580
 581     proto_tree_add_item(sdp_timezone_tree,hf_timezone_time,tvb,
 582                         offset, tokenlen, FALSE);
 583     offset = next_offset + 1;
 584     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 585     if(next_offset != -1){
 586       tokenlen = next_offset - offset;
 587     } else {
 588       tokenlen = -1;    /* end of tvbuff */
 589     }
 590     proto_tree_add_item(sdp_timezone_tree,hf_timezone_offset,tvb,
 591                         offset, tokenlen, FALSE);
 592     offset = next_offset + 1;
 593   } while (next_offset != -1);
 594
 595 }
 596
 597
 598 static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti){
 599   proto_tree *sdp_encryption_key_tree;
 600   gint offset, next_offset, tokenlen;
 601
 602   offset = 0;
 603   next_offset = 0;
 604   tokenlen = 0;
 605
 606   sdp_encryption_key_tree = proto_item_add_subtree(ti,ett_sdp_encryption_key);
 607
 608   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 609
 610   if(next_offset == -1)
 611     return;
 612
 613   tokenlen = next_offset - offset;
 614
 615   proto_tree_add_item(sdp_encryption_key_tree,hf_encryption_key_type,
 616                       tvb, offset, tokenlen, FALSE);
 617
 618   offset = next_offset + 1;
 619   proto_tree_add_item(sdp_encryption_key_tree,hf_encryption_key_data,
 620                       tvb, offset, -1, FALSE);
 621
 622 }
 623
 624
 625
 626 static void dissect_sdp_session_attribute(tvbuff_t *tvb, proto_item * ti){
 627   proto_tree *sdp_session_attribute_tree;
 628   gint offset, next_offset, tokenlen;
 629
 630   offset = 0;
 631   next_offset = 0;
 632   tokenlen = 0;
 633
 634   sdp_session_attribute_tree = proto_item_add_subtree(ti,
 635                                                       ett_sdp_session_attribute);
 636
 637   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 638
 639   if(next_offset == -1)
 640     return;
 641
 642   tokenlen = next_offset - offset;
 643
 644   proto_tree_add_item(sdp_session_attribute_tree,
 645                       hf_session_attribute_field,
 646                       tvb, offset, tokenlen, FALSE);
 647
 648   offset = next_offset + 1;
 649   proto_tree_add_item(sdp_session_attribute_tree,
 650                       hf_session_attribute_value,
 651                       tvb, offset, -1, FALSE);
 652
 653 }
 654
 655 static void
 656 dissect_sdp_media(tvbuff_t *tvb, proto_item *ti){
 657   proto_tree *sdp_media_tree;
 658   gint offset, next_offset, tokenlen;
 659
 660   offset = 0;
 661   next_offset = 0;
 662   tokenlen = 0;
 663
 664   sdp_media_tree = proto_item_add_subtree(ti,ett_sdp_media);
 665
 666   next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 667
 668   if(next_offset == -1)
 669     return;
 670
 671   tokenlen = next_offset - offset;
 672
 673   proto_tree_add_item(sdp_media_tree, hf_media_media, tvb,
 674                       offset, tokenlen, FALSE);
 675
 676   offset = next_offset + 1;
 677
 678   next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 679   if(next_offset == -1)
 680     return;
 681   tokenlen = next_offset - offset;
 682   next_offset = tvb_find_guint8(tvb,offset, tokenlen, '/');
 683
 684   if(next_offset != -1){
 685     tokenlen = next_offset - offset;
 686
 687     proto_tree_add_item(sdp_media_tree, hf_media_port, tvb,
 688                         offset, tokenlen, FALSE);
 689     offset = next_offset + 1;
 690     next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 691     if(next_offset == -1)
 692       return;
 693     tokenlen = next_offset - offset;
 694     proto_tree_add_item(sdp_media_tree, hf_media_portcount, tvb,
 695                         offset, tokenlen, FALSE);
 696     offset = next_offset + 1;
 697   } else {
 698     next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 699
 700     if(next_offset == -1)
 701       return;
 702     tokenlen = next_offset - offset;
 703
 704     proto_tree_add_item(sdp_media_tree, hf_media_port, tvb,
 705                         offset, tokenlen, FALSE);
 706     offset = next_offset + 1;
 707   }
 708
 709   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 710
 711   if( next_offset == -1)
 712     return;
 713
 714   tokenlen = next_offset - offset;
 715
 716   proto_tree_add_item(sdp_media_tree, hf_media_proto, tvb,
 717                       offset, tokenlen, FALSE);
 718
 719   do{
 720     offset = next_offset + 1;
 721     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 722
 723     if(next_offset == -1){
 724       tokenlen = -1;    /* End of tvbuff */
 725     } else {
 726       tokenlen = next_offset - offset;
 727     }
 728
 729     proto_tree_add_item(sdp_media_tree, hf_media_format, tvb,
 730                         offset, tokenlen, FALSE);
 731   } while (next_offset != -1);
 732
 733 }
 734
 735 static void dissect_sdp_media_attribute(tvbuff_t *tvb, proto_item * ti){
 736   proto_tree *sdp_media_attribute_tree;
 737   gint offset, next_offset, tokenlen;
 738
 739   offset = 0;
 740   next_offset = 0;
 741   tokenlen = 0;
 742
 743   sdp_media_attribute_tree = proto_item_add_subtree(ti,
 744                                                       ett_sdp_media_attribute);
 745
 746   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 747
 748   if(next_offset == -1)
 749     return;
 750
 751   tokenlen = next_offset - offset;
 752
 753   proto_tree_add_item(sdp_media_attribute_tree,
 754                       hf_media_attribute_field,
 755                       tvb, offset, tokenlen, FALSE);
 756
 757   offset = next_offset + 1;
 758   proto_tree_add_item(sdp_media_attribute_tree,
 759                       hf_media_attribute_value,
 760                       tvb, offset, -1, FALSE);
 761
 762 }
 763
 764 void
 765 proto_register_sdp(void)
 766 {
 767   static hf_register_info hf[] = {
 768     { &hf_protocol_version,
 769       { "Session Description Protocol Version (v)",
 770         "sdp.version", FT_STRING, BASE_NONE,NULL,0x0,
 771         "Session Description Protocol Version", HFILL }},
 772     { &hf_owner,
 773       { "Owner/Creator, Session Id (o)",
 774         "sdp.owner", FT_STRING, BASE_NONE, NULL, 0x0,
 775         "Owner/Creator, Session Id", HFILL}},
 776     { &hf_session_name,
 777       { "Session Name (s)",
 778         "sdp.session_name", FT_STRING, BASE_NONE,NULL, 0x0,
 779         "Session Name", HFILL }},
 780     { &hf_session_info,
 781       { "Session Information (i)",
 782         "sdp.session_info", FT_STRING, BASE_NONE, NULL, 0x0,
 783         "Session Information", HFILL }},
 784     { &hf_uri,
 785       { "URI of Description (u)",
 786         "sdp.uri", FT_STRING, BASE_NONE,NULL, 0x0,
 787         "URI of Description", HFILL }},
 788     { &hf_email,
 789       { "E-mail Address (e)",
 790         "sdp.email", FT_STRING, BASE_NONE, NULL, 0x0,
 791         "E-mail Address", HFILL }},
 792     { &hf_phone,
 793       { "Phone Number (p)",
 794         "sdp.phone", FT_STRING, BASE_NONE, NULL, 0x0,
 795         "Phone Number", HFILL }},
 796     { &hf_connection_info,
 797       { "Connection Information (c)",
 798         "sdp.connection_info", FT_STRING, BASE_NONE, NULL, 0x0,
 799         "Connection Information", HFILL }},
 800     { &hf_bandwidth,
 801       { "Bandwidth Information (b)",
 802         "sdp.bandwidth", FT_STRING, BASE_NONE, NULL, 0x0,
 803         "Bandwidth Information", HFILL }},
 804     { &hf_timezone,
 805       { "Time Zone Adjustments (z)",
 806         "sdp.timezone", FT_STRING, BASE_NONE, NULL, 0x0,
 807         "Time Zone Adjustments", HFILL }},
 808     { &hf_encryption_key,
 809       { "Encryption Key (k)",
 810         "sdp.encryption_key", FT_STRING, BASE_NONE, NULL, 0x0,
 811         "Encryption Key", HFILL }},
 812     { &hf_session_attribute,
 813       { "Session Attribute (a)",
 814         "sdp.session_attr", FT_STRING, BASE_NONE, NULL, 0x0,
 815         "Session Attribute", HFILL }},
 816     { &hf_media_attribute,
 817       { "Media Attribute (a)",
 818         "sdp.media_attr", FT_STRING, BASE_NONE, NULL, 0x0,
 819         "Media Attribute", HFILL }},
 820     { &hf_time,
 821       { "Time Description, active time (t)",
 822         "sdp.time", FT_STRING, BASE_NONE, NULL, 0x0,
 823         "Time Description, active time", HFILL }},
 824     { &hf_repeat_time,
 825       { "Repeat Time (r)",
 826         "sdp.repeat_time", FT_STRING, BASE_NONE, NULL, 0x0,
 827         "Repeat Time", HFILL }},
 828     { &hf_media,
 829       { "Media Description, name and address (m)",
 830         "sdp.media", FT_STRING, BASE_NONE, NULL, 0x0,
 831         "Media Description, name and address", HFILL }},
 832     { &hf_media_title,
 833       { "Media Title (i)",
 834         "sdp.media_title",FT_STRING, BASE_NONE, NULL, 0x0,
 835         "Media Title", HFILL }},
 836     { &hf_unknown,
 837       { "Unknown",
 838         "sdp.unknown",FT_STRING, BASE_NONE, NULL, 0x0,
 839         "Unknown", HFILL }},
 840     { &hf_misplaced,
 841       { "Misplaced",
 842         "sdp.misplaced",FT_STRING, BASE_NONE, NULL, 0x0,
 843         "Misplaced", HFILL }},
 844     { &hf_invalid,
 845       { "Invalid line",
 846         "sdp.invalid",FT_STRING, BASE_NONE, NULL, 0x0,
 847         "Invalid line", HFILL }},
 848     { &hf_owner_username,
 849       { "Owner Username",
 850         "sdp.owner.username",FT_STRING, BASE_NONE, NULL, 0x0,
 851         "Owner Username", HFILL }},
 852     { &hf_owner_sessionid,
 853       { "Session ID",
 854         "sdp.owner.sessionid",FT_STRING, BASE_NONE, NULL, 0x0,
 855         "Session ID", HFILL }},
 856     { &hf_owner_version,
 857       { "Session Version",
 858         "sdp.owner.version",FT_STRING, BASE_NONE, NULL, 0x0,
 859         "Session Version", HFILL }},
 860     { &hf_owner_network_type,
 861       { "Owner Network Type",
 862         "sdp.owner.network_type",FT_STRING, BASE_NONE, NULL, 0x0,
 863         "Owner Network Type", HFILL }},
 864     { &hf_owner_address_type,
 865       { "Owner Address Type",
 866         "sdp.owner.address_type",FT_STRING, BASE_NONE, NULL, 0x0,
 867         "Owner Address Type", HFILL }},
 868     { &hf_owner_address,
 869       { "Owner Address",
 870         "sdp.owner.address",FT_STRING, BASE_NONE, NULL, 0x0,
 871         "Owner Address", HFILL }},
 872     { &hf_connection_info_network_type,
 873       { "Connection Network Type",
 874         "sdp.connection_info.network_type",FT_STRING, BASE_NONE, NULL, 0x0,
 875         "Connection Network Type", HFILL }},
 876     { &hf_connection_info_address_type,
 877       { "Connection Address Type",
 878         "sdp.connection_info.address_type",FT_STRING, BASE_NONE, NULL, 0x0,
 879         "Connection Address Type", HFILL }},
 880     { &hf_connection_info_connection_address,
 881       { "Connection Address",
 882         "sdp.connection_info.address",FT_STRING, BASE_NONE, NULL, 0x0,
 883         "Connection Address", HFILL }},
 884     { &hf_connection_info_ttl,
 885       { "Connection TTL",
 886         "sdp.connection_info.ttl",FT_STRING, BASE_NONE, NULL, 0x0,
 887         "Connection TTL", HFILL }},
 888     { &hf_connection_info_num_addr,
 889       { "Connection Number of Addresses",
 890         "sdp.connection_info.num_addr",FT_STRING, BASE_NONE, NULL, 0x0,
 891         "Connection Number of Addresses", HFILL }},
 892     { &hf_bandwidth_modifier,
 893       { "Bandwidth Modifier",
 894         "sdp.bandwidth.modifier",FT_STRING, BASE_NONE, NULL, 0x0,
 895         "Bandwidth Modifier", HFILL }},
 896     { &hf_bandwidth_value,
 897       { "Bandwidth Value",
 898         "sdp.bandwidth.value",FT_STRING, BASE_NONE, NULL, 0x0,
 899         "Bandwidth Value", HFILL }},
 900     { &hf_time_start,
 901       { "Session Start Time",
 902         "sdp.time.start",FT_STRING, BASE_NONE, NULL, 0x0,
 903         "Session Start Time", HFILL }},
 904     { &hf_time_stop,
 905       { "Session Stop Time",
 906         "sdp.time.stop",FT_STRING, BASE_NONE, NULL, 0x0,
 907         "Session Stop Time", HFILL }},
 908     { &hf_repeat_time_interval,
 909       { "Repeat Interval",
 910         "sdp.repeat_time.interval",FT_STRING, BASE_NONE, NULL, 0x0,
 911         "Repeat Interval", HFILL }},
 912     { &hf_repeat_time_duration,
 913       { "Repeat Duration",
 914         "sdp.repeat_time.duration",FT_STRING, BASE_NONE, NULL, 0x0,
 915         "Repeat Duration", HFILL }},
 916     { &hf_repeat_time_offset,
 917       { "Repeat Offset",
 918         "sdp.repeat_time.offset",FT_STRING, BASE_NONE, NULL, 0x0,
 919         "Repeat Offset", HFILL }},
 920     { &hf_timezone_time,
 921       { "Timezone Time",
 922         "sdp.timezone.time",FT_STRING, BASE_NONE, NULL, 0x0,
 923         "Timezone Time", HFILL }},
 924     { &hf_timezone_offset,
 925       { "Timezone Offset",
 926         "sdp.timezone.offset",FT_STRING, BASE_NONE, NULL, 0x0,
 927         "Timezone Offset", HFILL }},
 928     { &hf_encryption_key_type,
 929       { "Key Type",
 930         "sdp.encryption_key.type",FT_STRING, BASE_NONE, NULL, 0x0,
 931         "Type", HFILL }},
 932     { &hf_encryption_key_data,
 933       { "Key Data",
 934         "sdp.encryption_key.data",FT_STRING, BASE_NONE, NULL, 0x0,
 935         "Data", HFILL }},
 936     { &hf_session_attribute_field,
 937       { "Session Attribute Fieldname",
 938         "sdp.session_attr.field",FT_STRING, BASE_NONE, NULL, 0x0,
 939         "Session Attribute Fieldname", HFILL }},
 940     { &hf_session_attribute_value,
 941       { "Session Attribute Value",
 942         "sdp.session_attr.value",FT_STRING, BASE_NONE, NULL, 0x0,
 943         "Session Attribute Value", HFILL }},
 944     { &hf_media_media,
 945       { "Media Type",
 946         "sdp.media.media",FT_STRING, BASE_NONE, NULL, 0x0,
 947         "Media Type", HFILL }},
 948     { &hf_media_port,
 949       { "Media Port",
 950         "sdp.media.port",FT_STRING, BASE_NONE, NULL, 0x0,
 951         "Media Port", HFILL }},
 952     { &hf_media_portcount,
 953       { "Media Port Count",
 954         "sdp.media.portcount",FT_STRING, BASE_NONE, NULL, 0x0,
 955         "Media Port Count", HFILL }},
 956     { &hf_media_proto,
 957       { "Media Proto",
 958         "sdp.media.proto",FT_STRING, BASE_NONE, NULL, 0x0,
 959         "Media Proto", HFILL }},
 960     { &hf_media_format,
 961       { "Media Format",
 962         "sdp.media.format",FT_STRING, BASE_NONE, NULL, 0x0,
 963         "Media Format", HFILL }},
 964     { &hf_media_attribute_field,
 965       { "Media Attribute Fieldname",
 966         "sdp.media_attribute.field",FT_STRING, BASE_NONE, NULL, 0x0,
 967         "Media Attribute Fieldname", HFILL }},
 968     { &hf_media_attribute_value,
 969       { "Media Attribute Value",
 970         "sdp.media_attribute.value",FT_STRING, BASE_NONE, NULL, 0x0,
 971         "Media Attribute Value", HFILL }},
 972
 973   };
 974   static gint *ett[] = {
 975     &ett_sdp,
 976     &ett_sdp_owner,
 977     &ett_sdp_connection_info,
 978     &ett_sdp_bandwidth,
 979     &ett_sdp_time,
 980     &ett_sdp_repeat_time,
 981     &ett_sdp_timezone,
 982     &ett_sdp_encryption_key,
 983     &ett_sdp_session_attribute,
 984     &ett_sdp_media,
 985     &ett_sdp_media_attribute,
 986   };
 987
 988   proto_sdp = proto_register_protocol("Session Description Protocol",
 989                                       "SDP", "sdp");
 990   proto_register_field_array(proto_sdp, hf, array_length(hf));
 991   proto_register_subtree_array(ett, array_length(ett));
 992
 993   /*
 994    * Register the dissector by name, so other dissectors can
 995    * grab it by name rather than just referring to it directly
 996    * (you can't refer to it directly from a plugin dissector
 997    * on Windows without stuffing it into the Big Transfer Vector).
 998    */
 999   register_dissector("sdp", dissect_sdp, proto_sdp);
1000 }