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 1.34 2003/06/12 08:33:29 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 #include <string.h>
  31 #include <ctype.h>
  32
  33 #include <glib.h>
  34 #include <epan/packet.h>
  35 #include <epan/strutil.h>
  36
  37 static int proto_sdp = -1;
  38
  39 /* Top level fields */
  40 static int hf_protocol_version = -1;
  41 static int hf_owner = -1;
  42 static int hf_session_name = -1;
  43 static int hf_session_info = -1;
  44 static int hf_uri = -1;
  45 static int hf_email = -1;
  46 static int hf_phone = -1;
  47 static int hf_connection_info = -1;
  48 static int hf_bandwidth = -1;
  49 static int hf_timezone = -1;
  50 static int hf_encryption_key = -1;
  51 static int hf_session_attribute = -1;
  52 static int hf_media_attribute = -1;
  53 static int hf_time = -1;
  54 static int hf_repeat_time = -1;
  55 static int hf_media = -1;
  56 static int hf_media_title = -1;
  57 static int hf_unknown = -1;
  58 static int hf_invalid = -1;
  59
  60 /* hf_owner subfields*/
  61 static int hf_owner_username = -1;
  62 static int hf_owner_sessionid = -1;
  63 static int hf_owner_version = -1;
  64 static int hf_owner_network_type = -1;
  65 static int hf_owner_address_type = -1;
  66 static int hf_owner_address = -1;
  67
  68 /* hf_connection_info subfields */
  69 static int hf_connection_info_network_type = -1;
  70 static int hf_connection_info_address_type = -1;
  71 static int hf_connection_info_connection_address = -1;
  72 static int hf_connection_info_ttl = -1;
  73 static int hf_connection_info_num_addr = -1;
  74
  75 /* hf_bandwidth subfields */
  76 static int hf_bandwidth_modifier = -1;
  77 static int hf_bandwidth_value = -1;
  78
  79 /* hf_time subfields */
  80 static int hf_time_start = -1;
  81 static int hf_time_stop = -1;
  82
  83 /* hf_repeat_time subfield */
  84 static int hf_repeat_time_interval = -1;
  85 static int hf_repeat_time_duration = -1;
  86 static int hf_repeat_time_offset = -1;
  87
  88 /* hf_timezone subfields */
  89 static int hf_timezone_time = -1;
  90 static int hf_timezone_offset = -1;
  91
  92 /* hf_encryption_key subfields */
  93 static int hf_encryption_key_type = -1;
  94 static int hf_encryption_key_data = -1;
  95
  96 /* hf_session_attribute subfields */
  97 static int hf_session_attribute_field = -1;
  98 static int hf_session_attribute_value = -1;
  99
 100 /* hf_media subfields */
 101 static int hf_media_media = -1;
 102 static int hf_media_port = -1;
 103 static int hf_media_portcount = -1;
 104 static int hf_media_proto = -1;
 105 static int hf_media_format = -1;
 106
 107 /* hf_session_attribute subfields */
 108 static int hf_media_attribute_field = -1;
 109 static int hf_media_attribute_value = -1;
 110
 111 /* trees */
 112 static int ett_sdp = -1;
 113 static int ett_sdp_owner = -1;
 114 static int ett_sdp_connection_info = -1;
 115 static int ett_sdp_bandwidth = -1;
 116 static int ett_sdp_time = -1;
 117 static int ett_sdp_repeat_time = -1;
 118 static int ett_sdp_timezone = -1;
 119 static int ett_sdp_encryption_key = -1;
 120 static int ett_sdp_session_attribute = -1;
 121 static int ett_sdp_media = -1;
 122 static int ett_sdp_media_attribute = -1;
 123
 124 /* static functions */
 125
 126 static void call_sdp_subdissector(tvbuff_t *tvb, int hf, proto_tree* ti);
 127
 128 /* Subdissector functions */
 129 static void dissect_sdp_owner(tvbuff_t *tvb, proto_item* ti);
 130 static void dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti);
 131 static void dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti);
 132 static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti);
 133 static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti);
 134 static void dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti);
 135 static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti);
 136 static void dissect_sdp_session_attribute(tvbuff_t *tvb, proto_item *ti);
 137 static void dissect_sdp_media(tvbuff_t *tvb, proto_item *ti);
 138 static void dissect_sdp_media_attribute(tvbuff_t *tvb, proto_item *ti);
 139
 140 static void
 141 dissect_sdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 142 {
 143         proto_tree      *sdp_tree;
 144         proto_item      *ti, *sub_ti;
 145         gint            offset = 0;
 146         gint            next_offset;
 147         int             linelen;
 148         gboolean        in_media_description;
 149         guchar          type;
 150         guchar          delim;
 151         int             datalen;
 152         int             tokenoffset;
 153         int             hf = -1;
 154         char            *string;
 155
 156         /*
 157          * As RFC 2327 says, "SDP is purely a format for session
 158          * description - it does not incorporate a transport protocol,
 159          * and is intended to use different transport protocols as
 160          * appropriate including the Session Announcement Protocol,
 161          * Session Initiation Protocol, Real-Time Streaming Protocol,
 162          * electronic mail using the MIME extensions, and the
 163          * Hypertext Transport Protocol."
 164          *
 165          * We therefore don't set the protocol or info columns;
 166          * instead, we append to them, so that we don't erase
 167          * what the protocol inside which the SDP stuff resides
 168          * put there.
 169          */
 170         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 171                 col_append_str(pinfo->cinfo, COL_PROTOCOL, "/SDP");
 172
 173         if (check_col(pinfo->cinfo, COL_INFO)) {
 174                 /* XXX: Needs description. */
 175                 col_append_str(pinfo->cinfo, COL_INFO, ", with session description");
 176         }
 177
 178         if (!tree)
 179                 return;
 180
 181         ti = proto_tree_add_item(tree, proto_sdp, tvb, offset, -1, FALSE);
 182         sdp_tree = proto_item_add_subtree(ti, ett_sdp);
 183
 184         /*
 185          * Show the SDP message a line at a time.
 186          */
 187         in_media_description = FALSE;
 188         while (tvb_offset_exists(tvb, offset)) {
 189                 /*
 190                  * Find the end of the line.
 191                  */
 192                 linelen = tvb_find_line_end_unquoted(tvb, offset, -1,
 193                     &next_offset);
 194
 195                 /*
 196                  * Line must contain at least e.g. "v=".
 197                  */
 198                 if (linelen < 2)
 199                         break;
 200
 201                 type = tvb_get_guint8(tvb,offset);
 202                 delim = tvb_get_guint8(tvb,offset + 1);
 203                 if (delim != '=') {
 204                         proto_tree_add_item(sdp_tree,hf_invalid,tvb, offset,
 205                                               linelen, FALSE);
 206                         offset = next_offset;
 207                         continue;
 208                 }
 209
 210                 /*
 211                  * Attributes.
 212                  */
 213                 switch (type) {
 214                 case 'v':
 215                         hf = hf_protocol_version;
 216                         break;
 217                 case 'o':
 218                         hf = hf_owner;
 219                         break;
 220                 case 's':
 221                         hf = hf_session_name;
 222                         break;
 223                 case 'i':
 224                         if (in_media_description) {
 225                                 hf = hf_media_title;
 226                         }
 227                         else{
 228                                 hf = hf_session_info;
 229                         }
 230                         break;
 231                 case 'u':
 232                         hf = hf_uri;
 233                         break;
 234                 case 'e':
 235                         hf = hf_email;
 236                         break;
 237                 case 'p':
 238                         hf = hf_phone;
 239                         break;
 240                 case 'c':
 241                         hf = hf_connection_info;
 242                         break;
 243                 case 'b':
 244                         hf = hf_bandwidth;
 245                         break;
 246                 case 't':
 247                         hf = hf_time;
 248                         break;
 249                 case 'r':
 250                         hf = hf_repeat_time;
 251                         break;
 252                 case 'm':
 253                         hf = hf_media;
 254                         in_media_description = TRUE;
 255                         break;
 256                 case 'k':
 257                         hf = hf_encryption_key;
 258                         break;
 259                 case 'a':
 260                         if (in_media_description) {
 261                                 hf = hf_media_attribute;
 262                         }
 263                         else{
 264                                 hf = hf_session_attribute;
 265                         }
 266                         break;
 267                 case 'z':
 268                         hf = hf_timezone;
 269                         break;
 270                 default:
 271                         hf = hf_unknown;
 272                         break;
 273                 }
 274                 tokenoffset = 2;
 275                 if (hf == hf_unknown)
 276                         tokenoffset = 0;
 277                 string = tvb_get_string(tvb, offset + tokenoffset,
 278                     linelen - tokenoffset);
 279                 sub_ti = proto_tree_add_string_format(sdp_tree,hf,tvb, offset,
 280                                                linelen, string,
 281                                                "%s: %s",
 282                                                proto_registrar_get_name(hf),
 283                                                format_text(string,
 284                                                  linelen - tokenoffset));
 285                 g_free(string);
 286                 call_sdp_subdissector(tvb_new_subset(tvb,offset+tokenoffset,
 287                                                      linelen-tokenoffset,-1),
 288                                       hf,sub_ti);
 289                 offset = next_offset;
 290         }
 291
 292         datalen = tvb_length_remaining(tvb, offset);
 293         if (datalen > 0) {
 294                 proto_tree_add_text(sdp_tree, tvb, offset, datalen,
 295                     "Data (%d bytes)", datalen);
 296         }
 297 }
 298
 299 static void
 300 call_sdp_subdissector(tvbuff_t *tvb, int hf, proto_tree* ti){
 301   if(hf == hf_owner){
 302     dissect_sdp_owner(tvb,ti);
 303   } else if ( hf == hf_connection_info) {
 304     dissect_sdp_connection_info(tvb,ti);
 305   } else if ( hf == hf_bandwidth) {
 306     dissect_sdp_bandwidth(tvb,ti);
 307   } else if ( hf == hf_time) {
 308     dissect_sdp_time(tvb,ti);
 309   } else if ( hf == hf_repeat_time ){
 310     dissect_sdp_repeat_time(tvb,ti);
 311   } else if ( hf == hf_timezone ) {
 312     dissect_sdp_timezone(tvb,ti);
 313   } else if ( hf == hf_encryption_key ) {
 314     dissect_sdp_encryption_key(tvb,ti);
 315   } else if ( hf == hf_session_attribute ){
 316     dissect_sdp_session_attribute(tvb,ti);
 317   } else if ( hf == hf_media ) {
 318     dissect_sdp_media(tvb,ti);
 319   } else if ( hf == hf_media_attribute ){
 320     dissect_sdp_media_attribute(tvb,ti);
 321   }
 322 }
 323
 324 static void
 325 dissect_sdp_owner(tvbuff_t *tvb, proto_item *ti){
 326   proto_tree *sdp_owner_tree;
 327   gint offset,next_offset,tokenlen;
 328
 329   offset = 0;
 330   next_offset = 0;
 331   tokenlen = 0;
 332
 333   sdp_owner_tree = proto_item_add_subtree(ti,ett_sdp_owner);
 334
 335   /* Find the username */
 336   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 337   if( next_offset == -1 )
 338     return;
 339   tokenlen = next_offset - offset;
 340
 341   proto_tree_add_item(sdp_owner_tree,hf_owner_username,tvb, offset,tokenlen,
 342                       FALSE);
 343   offset = next_offset  + 1;
 344
 345   /* Find the session id */
 346   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 347   if( next_offset == -1 )
 348     return;
 349   tokenlen = next_offset - offset;
 350
 351   proto_tree_add_item(sdp_owner_tree,hf_owner_sessionid, tvb,
 352                       offset,tokenlen,FALSE);
 353   offset = next_offset + 1;
 354
 355   /* Find the version */
 356   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 357   if( next_offset == -1 )
 358     return;
 359   tokenlen = next_offset - offset;
 360
 361   proto_tree_add_item(sdp_owner_tree,hf_owner_version, tvb,
 362                       offset,tokenlen,FALSE);
 363   offset = next_offset + 1;
 364
 365   /* Find the network type */
 366   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 367   if( next_offset == -1 )
 368     return;
 369   tokenlen = next_offset - offset;
 370
 371   proto_tree_add_item(sdp_owner_tree,hf_owner_network_type, tvb,
 372                       offset,tokenlen,FALSE);
 373   offset = next_offset + 1;
 374
 375   /* Find the address type */
 376   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 377   if( next_offset == -1 )
 378     return;
 379   tokenlen = next_offset - offset;
 380
 381   proto_tree_add_item(sdp_owner_tree,hf_owner_address_type, tvb,
 382                       offset,tokenlen,FALSE);
 383   offset = next_offset + 1;
 384
 385   /* Find the address */
 386   proto_tree_add_item(sdp_owner_tree,hf_owner_address, tvb, offset, -1, FALSE);
 387 }
 388
 389 static void
 390 dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti){
 391   proto_tree *sdp_connection_info_tree;
 392   gint offset,next_offset,tokenlen;
 393
 394   offset = 0;
 395   next_offset = 0;
 396   tokenlen = 0;
 397
 398   sdp_connection_info_tree = proto_item_add_subtree(ti,
 399                                                     ett_sdp_connection_info);
 400
 401   /* Find the network type */
 402   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 403   if( next_offset == -1 )
 404     return;
 405   tokenlen = next_offset - offset;
 406
 407   proto_tree_add_item(sdp_connection_info_tree,
 408                       hf_connection_info_network_type,tvb,
 409                       offset,tokenlen,FALSE);
 410   offset = next_offset + 1;
 411
 412   /* Find the address type */
 413   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 414   if( next_offset == -1 )
 415     return;
 416   tokenlen = next_offset - offset;
 417
 418   proto_tree_add_item(sdp_connection_info_tree,
 419                       hf_connection_info_address_type,tvb,
 420                       offset,tokenlen,FALSE);
 421   offset = next_offset + 1;
 422
 423   /* Find the connection address */
 424   next_offset = tvb_find_guint8(tvb,offset,-1,'/');
 425   if( next_offset == -1){
 426     tokenlen = -1;      /* end of tvbuff */
 427   } else {
 428     tokenlen = next_offset - offset;
 429   }
 430   proto_tree_add_item(sdp_connection_info_tree,
 431                       hf_connection_info_connection_address, tvb,
 432                       offset,tokenlen,FALSE);
 433   if(next_offset != -1){
 434     offset = next_offset + 1;
 435     next_offset = tvb_find_guint8(tvb,offset,-1,'/');
 436     if( next_offset == -1){
 437       tokenlen = -1;    /* end of tvbuff */
 438     } else {
 439       tokenlen = next_offset - offset;
 440     }
 441     proto_tree_add_item(sdp_connection_info_tree,
 442                         hf_connection_info_ttl,tvb,offset,tokenlen,FALSE);
 443     if(next_offset != -1){
 444       offset = next_offset + 1;
 445       proto_tree_add_item(sdp_connection_info_tree,
 446                           hf_connection_info_num_addr, tvb,
 447                           offset, -1, FALSE);
 448     }
 449   }
 450 }
 451
 452 static void
 453 dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti){
 454   proto_tree * sdp_bandwidth_tree;
 455   gint offset, next_offset, tokenlen;
 456
 457   offset = 0;
 458   next_offset = 0;
 459   tokenlen = 0;
 460
 461   sdp_bandwidth_tree = proto_item_add_subtree(ti,ett_sdp_bandwidth);
 462
 463   /* find the modifier */
 464   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 465
 466   if( next_offset == -1)
 467     return;
 468
 469   tokenlen = next_offset - offset;
 470
 471   proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_modifier,
 472                       tvb, offset, tokenlen, FALSE);
 473
 474   offset = next_offset + 1;
 475
 476   proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_value,
 477                       tvb, offset, -1, FALSE);
 478
 479 }
 480
 481 static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti){
 482   proto_tree *sdp_time_tree;
 483   gint offset,next_offset, tokenlen;
 484
 485   offset = 0;
 486   next_offset = 0;
 487   tokenlen = 0;
 488
 489   sdp_time_tree = proto_item_add_subtree(ti,ett_sdp_time);
 490
 491   /* get start time */
 492   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 493   if( next_offset == -1 )
 494     return;
 495
 496   tokenlen = next_offset - offset;
 497   proto_tree_add_item(sdp_time_tree, hf_time_start, tvb,
 498                       offset, tokenlen, FALSE);
 499
 500   /* get stop time */
 501   offset = next_offset + 1;
 502   proto_tree_add_item(sdp_time_tree,hf_time_start, tvb,
 503                       offset, -1, FALSE);
 504 }
 505
 506 static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti){
 507   proto_tree *sdp_repeat_time_tree;
 508   gint offset,next_offset, tokenlen;
 509
 510   offset = 0;
 511   next_offset = 0;
 512   tokenlen = 0;
 513
 514   sdp_repeat_time_tree = proto_item_add_subtree(ti,ett_sdp_time);
 515
 516   /* get interval */
 517   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 518   if( next_offset == -1 )
 519     return;
 520
 521   tokenlen = next_offset - offset;
 522   proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_interval, tvb,
 523                       offset, tokenlen, FALSE);
 524
 525   /* get duration */
 526   offset = next_offset + 1;
 527   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 528   if( next_offset == -1 )
 529     return;
 530
 531   tokenlen = next_offset - offset;
 532   proto_tree_add_item(sdp_repeat_time_tree,hf_repeat_time_duration, tvb,
 533                       offset, tokenlen, FALSE);
 534
 535   /* get offsets */
 536   do{
 537     offset = next_offset +1;
 538     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 539     if(next_offset != -1){
 540       tokenlen = next_offset - offset;
 541     } else {
 542       tokenlen = -1;    /* end of tvbuff */
 543     }
 544     proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_offset,
 545                         tvb, offset, tokenlen, FALSE);
 546   } while( next_offset != -1 );
 547
 548 }
 549 static void
 550 dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti){
 551   proto_tree* sdp_timezone_tree;
 552   gint offset, next_offset, tokenlen;
 553   offset = 0;
 554   next_offset = 0;
 555   tokenlen = 0;
 556
 557   sdp_timezone_tree = proto_item_add_subtree(ti,ett_sdp_timezone);
 558
 559   do{
 560     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 561     if(next_offset == -1)
 562       break;
 563     tokenlen = next_offset - offset;
 564
 565     proto_tree_add_item(sdp_timezone_tree,hf_timezone_time,tvb,
 566                         offset, tokenlen, FALSE);
 567     offset = next_offset + 1;
 568     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 569     if(next_offset != -1){
 570       tokenlen = next_offset - offset;
 571     } else {
 572       tokenlen = -1;    /* end of tvbuff */
 573     }
 574     proto_tree_add_item(sdp_timezone_tree,hf_timezone_offset,tvb,
 575                         offset, tokenlen, FALSE);
 576     offset = next_offset + 1;
 577   } while (next_offset != -1);
 578
 579 }
 580
 581
 582 static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti){
 583   proto_tree *sdp_encryption_key_tree;
 584   gint offset, next_offset, tokenlen;
 585
 586   offset = 0;
 587   next_offset = 0;
 588   tokenlen = 0;
 589
 590   sdp_encryption_key_tree = proto_item_add_subtree(ti,ett_sdp_encryption_key);
 591
 592   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 593
 594   if(next_offset == -1)
 595     return;
 596
 597   tokenlen = next_offset - offset;
 598
 599   proto_tree_add_item(sdp_encryption_key_tree,hf_encryption_key_type,
 600                       tvb, offset, tokenlen, FALSE);
 601
 602   offset = next_offset + 1;
 603   proto_tree_add_item(sdp_encryption_key_tree,hf_encryption_key_data,
 604                       tvb, offset, -1, FALSE);
 605
 606 }
 607
 608
 609
 610 static void dissect_sdp_session_attribute(tvbuff_t *tvb, proto_item * ti){
 611   proto_tree *sdp_session_attribute_tree;
 612   gint offset, next_offset, tokenlen;
 613
 614   offset = 0;
 615   next_offset = 0;
 616   tokenlen = 0;
 617
 618   sdp_session_attribute_tree = proto_item_add_subtree(ti,
 619                                                       ett_sdp_session_attribute);
 620
 621   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 622
 623   if(next_offset == -1)
 624     return;
 625
 626   tokenlen = next_offset - offset;
 627
 628   proto_tree_add_item(sdp_session_attribute_tree,
 629                       hf_session_attribute_field,
 630                       tvb, offset, tokenlen, FALSE);
 631
 632   offset = next_offset + 1;
 633   proto_tree_add_item(sdp_session_attribute_tree,
 634                       hf_session_attribute_value,
 635                       tvb, offset, -1, FALSE);
 636
 637 }
 638
 639 static void
 640 dissect_sdp_media(tvbuff_t *tvb, proto_item *ti){
 641   proto_tree *sdp_media_tree;
 642   gint offset, next_offset, tokenlen;
 643
 644   offset = 0;
 645   next_offset = 0;
 646   tokenlen = 0;
 647
 648   sdp_media_tree = proto_item_add_subtree(ti,ett_sdp_media);
 649
 650   next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 651
 652   if(next_offset == -1)
 653     return;
 654
 655   tokenlen = next_offset - offset;
 656
 657   proto_tree_add_item(sdp_media_tree, hf_media_media, tvb,
 658                       offset, tokenlen, FALSE);
 659
 660   offset = next_offset + 1;
 661
 662   next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 663   if(next_offset == -1)
 664     return;
 665   tokenlen = next_offset - offset;
 666   next_offset = tvb_find_guint8(tvb,offset, tokenlen, '/');
 667
 668   if(next_offset != -1){
 669     tokenlen = next_offset - offset;
 670
 671     proto_tree_add_item(sdp_media_tree, hf_media_port, tvb,
 672                         offset, tokenlen, FALSE);
 673     offset = next_offset + 1;
 674     next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 675     if(next_offset == -1)
 676       return;
 677     tokenlen = next_offset - offset;
 678     proto_tree_add_item(sdp_media_tree, hf_media_portcount, tvb,
 679                         offset, tokenlen, FALSE);
 680     offset = next_offset + 1;
 681   } else {
 682     next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 683
 684     if(next_offset == -1)
 685       return;
 686     tokenlen = next_offset - offset;
 687
 688     proto_tree_add_item(sdp_media_tree, hf_media_port, tvb,
 689                         offset, tokenlen, FALSE);
 690     offset = next_offset + 1;
 691   }
 692
 693   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 694
 695   if( next_offset == -1)
 696     return;
 697
 698   tokenlen = next_offset - offset;
 699
 700   proto_tree_add_item(sdp_media_tree, hf_media_proto, tvb,
 701                       offset, tokenlen, FALSE);
 702
 703   do{
 704     offset = next_offset + 1;
 705     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 706
 707     if(next_offset == -1){
 708       tokenlen = -1;    /* End of tvbuff */
 709     } else {
 710       tokenlen = next_offset - offset;
 711     }
 712
 713     proto_tree_add_item(sdp_media_tree, hf_media_format, tvb,
 714                         offset, tokenlen, FALSE);
 715   } while (next_offset != -1);
 716
 717 }
 718
 719 static void dissect_sdp_media_attribute(tvbuff_t *tvb, proto_item * ti){
 720   proto_tree *sdp_media_attribute_tree;
 721   gint offset, next_offset, tokenlen;
 722
 723   offset = 0;
 724   next_offset = 0;
 725   tokenlen = 0;
 726
 727   sdp_media_attribute_tree = proto_item_add_subtree(ti,
 728                                                       ett_sdp_media_attribute);
 729
 730   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 731
 732   if(next_offset == -1)
 733     return;
 734
 735   tokenlen = next_offset - offset;
 736
 737   proto_tree_add_item(sdp_media_attribute_tree,
 738                       hf_media_attribute_field,
 739                       tvb, offset, tokenlen, FALSE);
 740
 741   offset = next_offset + 1;
 742   proto_tree_add_item(sdp_media_attribute_tree,
 743                       hf_media_attribute_value,
 744                       tvb, offset, -1, FALSE);
 745
 746 }
 747
 748 void
 749 proto_register_sdp(void)
 750 {
 751   static hf_register_info hf[] = {
 752     { &hf_protocol_version,
 753       { "Session Description Protocol Version (v)",
 754         "sdp.version", FT_STRING, BASE_NONE,NULL,0x0,
 755         "Session Description Protocol Version", HFILL }},
 756     { &hf_owner,
 757       { "Owner/Creator, Session Id (o)",
 758         "sdp.owner", FT_STRING, BASE_NONE, NULL, 0x0,
 759         "Owner/Creator, Session Id", HFILL}},
 760     { &hf_session_name,
 761       { "Session Name (s)",
 762         "sdp.session_name", FT_STRING, BASE_NONE,NULL, 0x0,
 763         "Session Name", HFILL }},
 764     { &hf_session_info,
 765       { "Session Information (i)",
 766         "sdp.session_info", FT_STRING, BASE_NONE, NULL, 0x0,
 767         "Session Information", HFILL }},
 768     { &hf_uri,
 769       { "URI of Description (u)",
 770         "sdp.uri", FT_STRING, BASE_NONE,NULL, 0x0,
 771         "URI of Description", HFILL }},
 772     { &hf_email,
 773       { "E-mail Address (e)",
 774         "sdp.email", FT_STRING, BASE_NONE, NULL, 0x0,
 775         "E-mail Address", HFILL }},
 776     { &hf_phone,
 777       { "Phone Number (p)",
 778         "sdp.phone", FT_STRING, BASE_NONE, NULL, 0x0,
 779         "Phone Number", HFILL }},
 780     { &hf_connection_info,
 781       { "Connection Information (c)",
 782         "sdp.connection_info", FT_STRING, BASE_NONE, NULL, 0x0,
 783         "Connection Information", HFILL }},
 784     { &hf_bandwidth,
 785       { "Bandwidth Information (b)",
 786         "sdp.bandwidth", FT_STRING, BASE_NONE, NULL, 0x0,
 787         "Bandwidth Information", HFILL }},
 788     { &hf_timezone,
 789       { "Time Zone Adjustments (z)",
 790         "sdp.timezone", FT_STRING, BASE_NONE, NULL, 0x0,
 791         "Time Zone Adjustments", HFILL }},
 792     { &hf_encryption_key,
 793       { "Encryption Key (k)",
 794         "sdp.encryption_key", FT_STRING, BASE_NONE, NULL, 0x0,
 795         "Encryption Key", HFILL }},
 796     { &hf_session_attribute,
 797       { "Session Attribute (a)",
 798         "sdp.session_attr", FT_STRING, BASE_NONE, NULL, 0x0,
 799         "Session Attribute", HFILL }},
 800     { &hf_media_attribute,
 801       { "Media Attribute (a)",
 802         "sdp.media_attr", FT_STRING, BASE_NONE, NULL, 0x0,
 803         "Media Attribute", HFILL }},
 804     { &hf_time,
 805       { "Time Description, active time (t)",
 806         "sdp.time", FT_STRING, BASE_NONE, NULL, 0x0,
 807         "Time Description, active time", HFILL }},
 808     { &hf_repeat_time,
 809       { "Repeat Time (r)",
 810         "sdp.repeat_time", FT_STRING, BASE_NONE, NULL, 0x0,
 811         "Repeat Time", HFILL }},
 812     { &hf_media,
 813       { "Media Description, name and address (m)",
 814         "sdp.media", FT_STRING, BASE_NONE, NULL, 0x0,
 815         "Media Description, name and address", HFILL }},
 816     { &hf_media_title,
 817       { "Media Title (i)",
 818         "sdp.media_title",FT_STRING, BASE_NONE, NULL, 0x0,
 819         "Media Title", HFILL }},
 820     { &hf_unknown,
 821       { "Unknown",
 822         "sdp.unknown",FT_STRING, BASE_NONE, NULL, 0x0,
 823         "Unknown", HFILL }},
 824     { &hf_invalid,
 825       { "Invalid line",
 826         "sdp.invalid",FT_STRING, BASE_NONE, NULL, 0x0,
 827         "Invalid line", HFILL }},
 828     { &hf_owner_username,
 829       { "Owner Username",
 830         "sdp.owner.username",FT_STRING, BASE_NONE, NULL, 0x0,
 831         "Owner Username", HFILL }},
 832     { &hf_owner_sessionid,
 833       { "Session ID",
 834         "sdp.owner.sessionid",FT_STRING, BASE_NONE, NULL, 0x0,
 835         "Session ID", HFILL }},
 836     { &hf_owner_version,
 837       { "Session Version",
 838         "sdp.owner.version",FT_STRING, BASE_NONE, NULL, 0x0,
 839         "Session Version", HFILL }},
 840     { &hf_owner_network_type,
 841       { "Owner Network Type",
 842         "sdp.owner.network_type",FT_STRING, BASE_NONE, NULL, 0x0,
 843         "Owner Network Type", HFILL }},
 844     { &hf_owner_address_type,
 845       { "Owner Address Type",
 846         "sdp.owner.address_type",FT_STRING, BASE_NONE, NULL, 0x0,
 847         "Owner Address Type", HFILL }},
 848     { &hf_owner_address,
 849       { "Owner Address",
 850         "sdp.owner.address",FT_STRING, BASE_NONE, NULL, 0x0,
 851         "Owner Address", HFILL }},
 852     { &hf_connection_info_network_type,
 853       { "Connection Network Type",
 854         "sdp.connection_info.network_type",FT_STRING, BASE_NONE, NULL, 0x0,
 855         "Connection Network Type", HFILL }},
 856     { &hf_connection_info_address_type,
 857       { "Connection Address Type",
 858         "sdp.connection_info.address_type",FT_STRING, BASE_NONE, NULL, 0x0,
 859         "Connection Address Type", HFILL }},
 860     { &hf_connection_info_connection_address,
 861       { "Connection Address",
 862         "sdp.connection_info.address",FT_STRING, BASE_NONE, NULL, 0x0,
 863         "Connection Address", HFILL }},
 864     { &hf_connection_info_ttl,
 865       { "Connection TTL",
 866         "sdp.connection_info.ttl",FT_STRING, BASE_NONE, NULL, 0x0,
 867         "Connection TTL", HFILL }},
 868     { &hf_connection_info_num_addr,
 869       { "Connection Number of Addresses",
 870         "sdp.connection_info.num_addr",FT_STRING, BASE_NONE, NULL, 0x0,
 871         "Connection Number of Addresses", HFILL }},
 872     { &hf_bandwidth_modifier,
 873       { "Bandwidth Modifier",
 874         "sdp.bandwidth.modifier",FT_STRING, BASE_NONE, NULL, 0x0,
 875         "Bandwidth Modifier", HFILL }},
 876     { &hf_bandwidth_value,
 877       { "Bandwidth Value",
 878         "sdp.bandwidth.value",FT_STRING, BASE_NONE, NULL, 0x0,
 879         "Bandwidth Value", HFILL }},
 880     { &hf_time_start,
 881       { "Session Start Time",
 882         "sdp.time.start",FT_STRING, BASE_NONE, NULL, 0x0,
 883         "Session Start Time", HFILL }},
 884     { &hf_time_stop,
 885       { "Session Stop Time",
 886         "sdp.time.stop",FT_STRING, BASE_NONE, NULL, 0x0,
 887         "Session Stop Time", HFILL }},
 888     { &hf_repeat_time_interval,
 889       { "Repeat Interval",
 890         "sdp.repeat_time.interval",FT_STRING, BASE_NONE, NULL, 0x0,
 891         "Repeat Interval", HFILL }},
 892     { &hf_repeat_time_duration,
 893       { "Repeat Duration",
 894         "sdp.repeat_time.duration",FT_STRING, BASE_NONE, NULL, 0x0,
 895         "Repeat Duration", HFILL }},
 896     { &hf_repeat_time_offset,
 897       { "Repeat Offset",
 898         "sdp.repeat_time.offset",FT_STRING, BASE_NONE, NULL, 0x0,
 899         "Repeat Offset", HFILL }},
 900     { &hf_timezone_time,
 901       { "Timezone Time",
 902         "sdp.timezone.time",FT_STRING, BASE_NONE, NULL, 0x0,
 903         "Timezone Time", HFILL }},
 904     { &hf_timezone_offset,
 905       { "Timezone Offset",
 906         "sdp.timezone.offset",FT_STRING, BASE_NONE, NULL, 0x0,
 907         "Timezone Offset", HFILL }},
 908     { &hf_encryption_key_type,
 909       { "Key Type",
 910         "sdp.encryption_key.type",FT_STRING, BASE_NONE, NULL, 0x0,
 911         "Type", HFILL }},
 912     { &hf_encryption_key_data,
 913       { "Key Data",
 914         "sdp.encryption_key.data",FT_STRING, BASE_NONE, NULL, 0x0,
 915         "Data", HFILL }},
 916     { &hf_session_attribute_field,
 917       { "Session Attribute Fieldname",
 918         "sdp.session_attr.field",FT_STRING, BASE_NONE, NULL, 0x0,
 919         "Session Attribute Fieldname", HFILL }},
 920     { &hf_session_attribute_value,
 921       { "Session Attribute Value",
 922         "sdp.session_attr.value",FT_STRING, BASE_NONE, NULL, 0x0,
 923         "Session Attribute Value", HFILL }},
 924     { &hf_media_media,
 925       { "Media Type",
 926         "sdp.media.media",FT_STRING, BASE_NONE, NULL, 0x0,
 927         "Media Type", HFILL }},
 928     { &hf_media_port,
 929       { "Media Port",
 930         "sdp.media.port",FT_STRING, BASE_NONE, NULL, 0x0,
 931         "Media Port", HFILL }},
 932     { &hf_media_portcount,
 933       { "Media Port Count",
 934         "sdp.media.portcount",FT_STRING, BASE_NONE, NULL, 0x0,
 935         "Media Port Count", HFILL }},
 936     { &hf_media_proto,
 937       { "Media Proto",
 938         "sdp.media.proto",FT_STRING, BASE_NONE, NULL, 0x0,
 939         "Media Proto", HFILL }},
 940     { &hf_media_format,
 941       { "Media Format",
 942         "sdp.media.format",FT_STRING, BASE_NONE, NULL, 0x0,
 943         "Media Format", HFILL }},
 944     { &hf_media_attribute_field,
 945       { "Media Attribute Fieldname",
 946         "sdp.media_attribute.field",FT_STRING, BASE_NONE, NULL, 0x0,
 947         "Media Attribute Fieldname", HFILL }},
 948     { &hf_media_attribute_value,
 949       { "Media Attribute Value",
 950         "sdp.media_attribute.value",FT_STRING, BASE_NONE, NULL, 0x0,
 951         "Media Attribute Value", HFILL }},
 952
 953   };
 954   static gint *ett[] = {
 955     &ett_sdp,
 956     &ett_sdp_owner,
 957     &ett_sdp_connection_info,
 958     &ett_sdp_bandwidth,
 959     &ett_sdp_time,
 960     &ett_sdp_repeat_time,
 961     &ett_sdp_timezone,
 962     &ett_sdp_encryption_key,
 963     &ett_sdp_session_attribute,
 964     &ett_sdp_media,
 965     &ett_sdp_media_attribute,
 966   };
 967
 968   proto_sdp = proto_register_protocol("Session Description Protocol",
 969                                       "SDP", "sdp");
 970   proto_register_field_array(proto_sdp, hf, array_length(hf));
 971   proto_register_subtree_array(ett, array_length(ett));
 972
 973   /*
 974    * Register the dissector by name, so other dissectors can
 975    * grab it by name rather than just referring to it directly
 976    * (you can't refer to it directly from a plugin dissector
 977    * on Windows without stuffing it into the Big Transfer Vector).
 978    */
 979   register_dissector("sdp", dissect_sdp, proto_sdp);
 980 }