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 1.45 2004/01/16 19:51:55 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 <sys/types.h>
  34 #ifdef HAVE_SYS_SOCKET_H
  35 #include <sys/socket.h>
  36 #endif
  37 #ifdef HAVE_NETINET_IN_H
  38 # include <netinet/in.h>
  39 #endif
  40 #ifdef HAVE_ARPA_INET_H
  41 #include <arpa/inet.h>
  42 #endif
  43 #ifdef NEED_INET_ATON_H
  44 # include <epan/inet_aton.h>
  45 #endif
  46
  47 #include <glib.h>
  48 #include <epan/packet.h>
  49 #include <epan/conversation.h>
  50 #include <epan/strutil.h>
  51
  52 static dissector_handle_t rtp_handle=NULL;
  53 static dissector_handle_t rtcp_handle=NULL;
  54
  55 static int proto_sdp = -1;
  56
  57 /* Top level fields */
  58 static int hf_protocol_version = -1;
  59 static int hf_owner = -1;
  60 static int hf_session_name = -1;
  61 static int hf_session_info = -1;
  62 static int hf_uri = -1;
  63 static int hf_email = -1;
  64 static int hf_phone = -1;
  65 static int hf_connection_info = -1;
  66 static int hf_bandwidth = -1;
  67 static int hf_timezone = -1;
  68 static int hf_encryption_key = -1;
  69 static int hf_session_attribute = -1;
  70 static int hf_media_attribute = -1;
  71 static int hf_time = -1;
  72 static int hf_repeat_time = -1;
  73 static int hf_media = -1;
  74 static int hf_media_title = -1;
  75 static int hf_unknown = -1;
  76 static int hf_invalid = -1;
  77
  78 /* hf_owner subfields*/
  79 static int hf_owner_username = -1;
  80 static int hf_owner_sessionid = -1;
  81 static int hf_owner_version = -1;
  82 static int hf_owner_network_type = -1;
  83 static int hf_owner_address_type = -1;
  84 static int hf_owner_address = -1;
  85
  86 /* hf_connection_info subfields */
  87 static int hf_connection_info_network_type = -1;
  88 static int hf_connection_info_address_type = -1;
  89 static int hf_connection_info_connection_address = -1;
  90 static int hf_connection_info_ttl = -1;
  91 static int hf_connection_info_num_addr = -1;
  92
  93 /* hf_bandwidth subfields */
  94 static int hf_bandwidth_modifier = -1;
  95 static int hf_bandwidth_value = -1;
  96
  97 /* hf_time subfields */
  98 static int hf_time_start = -1;
  99 static int hf_time_stop = -1;
 100
 101 /* hf_repeat_time subfield */
 102 static int hf_repeat_time_interval = -1;
 103 static int hf_repeat_time_duration = -1;
 104 static int hf_repeat_time_offset = -1;
 105
 106 /* hf_timezone subfields */
 107 static int hf_timezone_time = -1;
 108 static int hf_timezone_offset = -1;
 109
 110 /* hf_encryption_key subfields */
 111 static int hf_encryption_key_type = -1;
 112 static int hf_encryption_key_data = -1;
 113
 114 /* hf_session_attribute subfields */
 115 static int hf_session_attribute_field = -1;
 116 static int hf_session_attribute_value = -1;
 117
 118 /* hf_media subfields */
 119 static int hf_media_media = -1;
 120 static int hf_media_port = -1;
 121 static int hf_media_portcount = -1;
 122 static int hf_media_proto = -1;
 123 static int hf_media_format = -1;
 124
 125 /* hf_session_attribute subfields */
 126 static int hf_media_attribute_field = -1;
 127 static int hf_media_attribute_value = -1;
 128
 129 /* trees */
 130 static int ett_sdp = -1;
 131 static int ett_sdp_owner = -1;
 132 static int ett_sdp_connection_info = -1;
 133 static int ett_sdp_bandwidth = -1;
 134 static int ett_sdp_time = -1;
 135 static int ett_sdp_repeat_time = -1;
 136 static int ett_sdp_timezone = -1;
 137 static int ett_sdp_encryption_key = -1;
 138 static int ett_sdp_session_attribute = -1;
 139 static int ett_sdp_media = -1;
 140 static int ett_sdp_media_attribute = -1;
 141
 142
 143 #define SDP_MAX_RTP_CHANNELS 4
 144
 145 typedef struct {
 146         char *connection_address;
 147         char *connection_type;
 148         char *media_port[SDP_MAX_RTP_CHANNELS];
 149         char *media_proto[SDP_MAX_RTP_CHANNELS];
 150         gint8 media_count;
 151 } transport_info_t;
 152
 153 /* static functions */
 154
 155 static void call_sdp_subdissector(tvbuff_t *tvb, int hf, proto_tree* ti,
 156                                   transport_info_t *transport_info);
 157
 158 /* Subdissector functions */
 159 static void dissect_sdp_owner(tvbuff_t *tvb, proto_item* ti);
 160 static void dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti,
 161                                         transport_info_t *transport_info);
 162 static void dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti);
 163 static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti);
 164 static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti);
 165 static void dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti);
 166 static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti);
 167 static void dissect_sdp_session_attribute(tvbuff_t *tvb, proto_item *ti);
 168 static void dissect_sdp_media(tvbuff_t *tvb, proto_item *ti,
 169                               transport_info_t *transport_info);
 170 static void dissect_sdp_media_attribute(tvbuff_t *tvb, proto_item *ti);
 171
 172 static void
 173 dissect_sdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 174 {
 175         proto_tree      *sdp_tree;
 176         proto_item      *ti, *sub_ti;
 177         gint            offset = 0;
 178         gint            next_offset;
 179         int             linelen;
 180         gboolean        in_media_description;
 181         guchar          type;
 182         guchar          delim;
 183         int             datalen;
 184         int             tokenoffset;
 185         int             hf = -1;
 186         char            *string;
 187
 188         address         src_addr;
 189         conversation_t  *conv=NULL;
 190
 191         transport_info_t transport_info;
 192
 193         guint32         ipv4_address=0;
 194         guint32         ipv4_port=0;
 195         gboolean        is_rtp=FALSE;
 196         gboolean        is_ipv4_addr=FALSE;
 197         struct in_addr  ipaddr;
 198         gint            n;
 199
 200         /* Initialise RTP channel info */
 201         transport_info.connection_address=NULL;
 202         transport_info.connection_type=NULL;
 203         for (n=0; n < SDP_MAX_RTP_CHANNELS; n++)
 204         {
 205             transport_info.media_port[n]=NULL;
 206             transport_info.media_proto[n]=NULL;
 207         }
 208         transport_info.media_count = 0;
 209
 210
 211         /*
 212          * As RFC 2327 says, "SDP is purely a format for session
 213          * description - it does not incorporate a transport protocol,
 214          * and is intended to use different transport protocols as
 215          * appropriate including the Session Announcement Protocol,
 216          * Session Initiation Protocol, Real-Time Streaming Protocol,
 217          * electronic mail using the MIME extensions, and the
 218          * Hypertext Transport Protocol."
 219          *
 220          * We therefore don't set the protocol or info columns;
 221          * instead, we append to them, so that we don't erase
 222          * what the protocol inside which the SDP stuff resides
 223          * put there.
 224          */
 225         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 226                 col_append_str(pinfo->cinfo, COL_PROTOCOL, "/SDP");
 227
 228         if (check_col(pinfo->cinfo, COL_INFO)) {
 229                 /* XXX: Needs description. */
 230                 col_append_str(pinfo->cinfo, COL_INFO, ", with session description");
 231         }
 232
 233         ti = proto_tree_add_item(tree, proto_sdp, tvb, offset, -1, FALSE);
 234         sdp_tree = proto_item_add_subtree(ti, ett_sdp);
 235
 236         /*
 237          * Show the SDP message a line at a time.
 238          */
 239         in_media_description = FALSE;
 240         while (tvb_reported_length_remaining(tvb, offset) > 0) {
 241                 /*
 242                  * Find the end of the line.
 243                  */
 244                 linelen = tvb_find_line_end_unquoted(tvb, offset, -1,
 245                     &next_offset);
 246
 247                 /*
 248                  * Line must contain at least e.g. "v=".
 249                  */
 250                 if (linelen < 2)
 251                         break;
 252
 253                 type = tvb_get_guint8(tvb,offset);
 254                 delim = tvb_get_guint8(tvb,offset + 1);
 255                 if (delim != '=') {
 256                         proto_tree_add_item(sdp_tree,hf_invalid,tvb, offset,
 257                                               linelen, FALSE);
 258                         offset = next_offset;
 259                         continue;
 260                 }
 261
 262                 /*
 263                  * Attributes.
 264                  */
 265                 switch (type) {
 266                 case 'v':
 267                         hf = hf_protocol_version;
 268                         break;
 269                 case 'o':
 270                         hf = hf_owner;
 271                         break;
 272                 case 's':
 273                         hf = hf_session_name;
 274                         break;
 275                 case 'i':
 276                         if (in_media_description) {
 277                                 hf = hf_media_title;
 278                         }
 279                         else{
 280                                 hf = hf_session_info;
 281                         }
 282                         break;
 283                 case 'u':
 284                         hf = hf_uri;
 285                         break;
 286                 case 'e':
 287                         hf = hf_email;
 288                         break;
 289                 case 'p':
 290                         hf = hf_phone;
 291                         break;
 292                 case 'c':
 293                         hf = hf_connection_info;
 294                         break;
 295                 case 'b':
 296                         hf = hf_bandwidth;
 297                         break;
 298                 case 't':
 299                         hf = hf_time;
 300                         break;
 301                 case 'r':
 302                         hf = hf_repeat_time;
 303                         break;
 304                 case 'm':
 305                         hf = hf_media;
 306                         in_media_description = TRUE;
 307                         break;
 308                 case 'k':
 309                         hf = hf_encryption_key;
 310                         break;
 311                 case 'a':
 312                         if (in_media_description) {
 313                                 hf = hf_media_attribute;
 314                         }
 315                         else{
 316                                 hf = hf_session_attribute;
 317                         }
 318                         break;
 319                 case 'z':
 320                         hf = hf_timezone;
 321                         break;
 322                 default:
 323                         hf = hf_unknown;
 324                         break;
 325                 }
 326                 tokenoffset = 2;
 327                 if (hf == hf_unknown)
 328                         tokenoffset = 0;
 329                 string = tvb_get_string(tvb, offset + tokenoffset,
 330                     linelen - tokenoffset);
 331                 sub_ti = proto_tree_add_string_format(sdp_tree,hf,tvb, offset,
 332                                                linelen, string,
 333                                                "%s: %s",
 334                                                proto_registrar_get_name(hf),
 335                                                format_text(string,
 336                                                  linelen - tokenoffset));
 337                 g_free(string);
 338                 call_sdp_subdissector(tvb_new_subset(tvb,offset+tokenoffset,
 339                                                      linelen-tokenoffset,
 340                                                      linelen-tokenoffset),
 341                                       hf,sub_ti,&transport_info),
 342                 offset = next_offset;
 343         }
 344
 345
 346         /* Now look, if we have strings collected.
 347          * Try to convert ipv4 addresses and ports into binary format,
 348          * so we can use them to detect rtp and rtcp streams.
 349          * Don't forget to free the strings!
 350          */
 351
 352         for (n = 0; n < transport_info.media_count; n++)
 353         {
 354             if(transport_info.media_port[n]!=NULL) {
 355                     ipv4_port = atol(transport_info.media_port[n]);
 356                     g_free(transport_info.media_port[n]);
 357             }
 358             if(transport_info.media_proto[n]!=NULL) {
 359                     /* Check if media protocol is RTP */
 360                     is_rtp = (strcmp(transport_info.media_proto[n],"RTP/AVP")==0);
 361                     g_free(transport_info.media_proto[n]);
 362             }
 363             if(transport_info.connection_address!=NULL) {
 364                     if(transport_info.connection_type!=NULL &&
 365                         strcmp(transport_info.connection_type,"IP4")==0) {
 366                             if(inet_aton(transport_info.connection_address, &ipaddr)
 367                                 !=0 ) {
 368                                     /* connection_address could be converted to a valid ipv4 address*/
 369                                     is_ipv4_addr=TRUE;
 370                                     ipv4_address = ipaddr.s_addr;
 371                             }
 372                     }
 373             }
 374
 375             /* Add rtp and rtcp conversation, if available */
 376             if((!pinfo->fd->flags.visited) && ipv4_address!=0 && ipv4_port!=0 && is_rtp && is_ipv4_addr){
 377                     src_addr.type=AT_IPv4;
 378                     src_addr.len=4;
 379                     src_addr.data=(char *)&ipv4_address;
 380
 381                     if(rtp_handle){
 382                             conv=find_conversation(&src_addr, &src_addr, PT_UDP, ipv4_port, ipv4_port, NO_ADDR_B|NO_PORT_B);
 383                             if(!conv){
 384                                     conv=conversation_new(&src_addr, &src_addr, PT_UDP, ipv4_port, ipv4_port, NO_ADDR2|NO_PORT2);
 385                                     conversation_set_dissector(conv, rtp_handle);
 386                             }
 387                     }
 388
 389                     if(rtcp_handle){
 390                             ipv4_port++;
 391                             conv=find_conversation(&src_addr, &src_addr, PT_UDP, ipv4_port, ipv4_port, NO_ADDR_B|NO_PORT_B);
 392                             if(!conv){
 393                                     conv=conversation_new(&src_addr, &src_addr, PT_UDP, ipv4_port, ipv4_port, NO_ADDR2|NO_PORT2);
 394                                     conversation_set_dissector(conv, rtcp_handle);
 395                             }
 396                     }
 397             }
 398         }
 399
 400         /* Free up 'connection info' strings */
 401         if(transport_info.connection_address) {
 402                 g_free(transport_info.connection_address);
 403         }
 404         if(transport_info.connection_type!=NULL) {
 405                 g_free(transport_info.connection_type);
 406         }
 407
 408
 409         datalen = tvb_length_remaining(tvb, offset);
 410         if (datalen > 0) {
 411                 proto_tree_add_text(sdp_tree, tvb, offset, datalen,
 412                     "Data (%d bytes)", datalen);
 413         }
 414 }
 415
 416 static void
 417 call_sdp_subdissector(tvbuff_t *tvb, int hf, proto_tree* ti,
 418                       transport_info_t *transport_info){
 419   if(hf == hf_owner){
 420     dissect_sdp_owner(tvb,ti);
 421   } else if ( hf == hf_connection_info) {
 422     dissect_sdp_connection_info(tvb,ti,transport_info);
 423   } else if ( hf == hf_bandwidth) {
 424     dissect_sdp_bandwidth(tvb,ti);
 425   } else if ( hf == hf_time) {
 426     dissect_sdp_time(tvb,ti);
 427   } else if ( hf == hf_repeat_time ){
 428     dissect_sdp_repeat_time(tvb,ti);
 429   } else if ( hf == hf_timezone ) {
 430     dissect_sdp_timezone(tvb,ti);
 431   } else if ( hf == hf_encryption_key ) {
 432     dissect_sdp_encryption_key(tvb,ti);
 433   } else if ( hf == hf_session_attribute ){
 434     dissect_sdp_session_attribute(tvb,ti);
 435   } else if ( hf == hf_media ) {
 436     dissect_sdp_media(tvb,ti,transport_info);
 437   } else if ( hf == hf_media_attribute ){
 438     dissect_sdp_media_attribute(tvb,ti);
 439   }
 440 }
 441
 442 static void
 443 dissect_sdp_owner(tvbuff_t *tvb, proto_item *ti){
 444   proto_tree *sdp_owner_tree;
 445   gint offset,next_offset,tokenlen;
 446
 447   offset = 0;
 448   next_offset = 0;
 449   tokenlen = 0;
 450
 451   sdp_owner_tree = proto_item_add_subtree(ti,ett_sdp_owner);
 452
 453   /* Find the username */
 454   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 455   if( next_offset == -1 )
 456     return;
 457   tokenlen = next_offset - offset;
 458
 459   proto_tree_add_item(sdp_owner_tree,hf_owner_username,tvb, offset,tokenlen,
 460                       FALSE);
 461   offset = next_offset  + 1;
 462
 463   /* Find the session id */
 464   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 465   if( next_offset == -1 )
 466     return;
 467   tokenlen = next_offset - offset;
 468
 469   proto_tree_add_item(sdp_owner_tree,hf_owner_sessionid, tvb,
 470                       offset,tokenlen,FALSE);
 471   offset = next_offset + 1;
 472
 473   /* Find the version */
 474   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 475   if( next_offset == -1 )
 476     return;
 477   tokenlen = next_offset - offset;
 478
 479   proto_tree_add_item(sdp_owner_tree,hf_owner_version, tvb,
 480                       offset,tokenlen,FALSE);
 481   offset = next_offset + 1;
 482
 483   /* Find the network type */
 484   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 485   if( next_offset == -1 )
 486     return;
 487   tokenlen = next_offset - offset;
 488
 489   proto_tree_add_item(sdp_owner_tree,hf_owner_network_type, tvb,
 490                       offset,tokenlen,FALSE);
 491   offset = next_offset + 1;
 492
 493   /* Find the address type */
 494   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 495   if( next_offset == -1 )
 496     return;
 497   tokenlen = next_offset - offset;
 498
 499   proto_tree_add_item(sdp_owner_tree,hf_owner_address_type, tvb,
 500                       offset,tokenlen,FALSE);
 501   offset = next_offset + 1;
 502
 503   /* Find the address */
 504   proto_tree_add_item(sdp_owner_tree,hf_owner_address, tvb, offset, -1, FALSE);
 505 }
 506
 507 /*
 508  * XXX - this can leak memory if an exception is thrown after we've fetched
 509  * a string.
 510  */
 511 static void
 512 dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti,
 513                             transport_info_t *transport_info){
 514   proto_tree *sdp_connection_info_tree;
 515   gint offset,next_offset,tokenlen;
 516
 517   offset = 0;
 518   next_offset = 0;
 519   tokenlen = 0;
 520
 521   sdp_connection_info_tree = proto_item_add_subtree(ti,
 522                                                     ett_sdp_connection_info);
 523
 524   /* Find the network type */
 525   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 526   if( next_offset == -1 )
 527     return;
 528   tokenlen = next_offset - offset;
 529
 530   proto_tree_add_item(sdp_connection_info_tree,
 531                       hf_connection_info_network_type,tvb,
 532                       offset,tokenlen,FALSE);
 533   offset = next_offset + 1;
 534
 535   /* Find the address type */
 536   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 537   if( next_offset == -1 )
 538     return;
 539   tokenlen = next_offset - offset;
 540   /* Save connection address type */
 541   transport_info->connection_type = tvb_get_string(tvb, offset, tokenlen);
 542
 543
 544   proto_tree_add_item(sdp_connection_info_tree,
 545                       hf_connection_info_address_type,tvb,
 546                       offset,tokenlen,FALSE);
 547   offset = next_offset + 1;
 548
 549   /* Find the connection address */
 550   /* XXX - what if there's a <number of addresses> value? */
 551   next_offset = tvb_find_guint8(tvb,offset,-1,'/');
 552   if( next_offset == -1){
 553     tokenlen = -1;      /* end of tvbuff */
 554     /* Save connection address */
 555     transport_info->connection_address =
 556         tvb_get_string(tvb, offset, tvb_length_remaining(tvb, offset));
 557   } else {
 558     tokenlen = next_offset - offset;
 559     /* Save connection address */
 560     transport_info->connection_address = tvb_get_string(tvb, offset, tokenlen);
 561   }
 562
 563   proto_tree_add_item(sdp_connection_info_tree,
 564                       hf_connection_info_connection_address, tvb,
 565                       offset,tokenlen,FALSE);
 566   if(next_offset != -1){
 567     offset = next_offset + 1;
 568     next_offset = tvb_find_guint8(tvb,offset,-1,'/');
 569     if( next_offset == -1){
 570       tokenlen = -1;    /* end of tvbuff */
 571     } else {
 572       tokenlen = next_offset - offset;
 573     }
 574     proto_tree_add_item(sdp_connection_info_tree,
 575                         hf_connection_info_ttl,tvb,offset,tokenlen,FALSE);
 576     if(next_offset != -1){
 577       offset = next_offset + 1;
 578       proto_tree_add_item(sdp_connection_info_tree,
 579                           hf_connection_info_num_addr, tvb,
 580                           offset, -1, FALSE);
 581     }
 582   }
 583 }
 584
 585 static void
 586 dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti){
 587   proto_tree * sdp_bandwidth_tree;
 588   gint offset, next_offset, tokenlen;
 589
 590   offset = 0;
 591   next_offset = 0;
 592   tokenlen = 0;
 593
 594   sdp_bandwidth_tree = proto_item_add_subtree(ti,ett_sdp_bandwidth);
 595
 596   /* find the modifier */
 597   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 598
 599   if( next_offset == -1)
 600     return;
 601
 602   tokenlen = next_offset - offset;
 603
 604   proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_modifier,
 605                       tvb, offset, tokenlen, FALSE);
 606
 607   offset = next_offset + 1;
 608
 609   proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_value,
 610                       tvb, offset, -1, FALSE);
 611
 612 }
 613
 614 static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti){
 615   proto_tree *sdp_time_tree;
 616   gint offset,next_offset, tokenlen;
 617
 618   offset = 0;
 619   next_offset = 0;
 620   tokenlen = 0;
 621
 622   sdp_time_tree = proto_item_add_subtree(ti,ett_sdp_time);
 623
 624   /* get start time */
 625   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 626   if( next_offset == -1 )
 627     return;
 628
 629   tokenlen = next_offset - offset;
 630   proto_tree_add_item(sdp_time_tree, hf_time_start, tvb,
 631                       offset, tokenlen, FALSE);
 632
 633   /* get stop time */
 634   offset = next_offset + 1;
 635   proto_tree_add_item(sdp_time_tree, hf_time_stop, tvb,
 636                       offset, -1, FALSE);
 637 }
 638
 639 static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti){
 640   proto_tree *sdp_repeat_time_tree;
 641   gint offset,next_offset, tokenlen;
 642
 643   offset = 0;
 644   next_offset = 0;
 645   tokenlen = 0;
 646
 647   sdp_repeat_time_tree = proto_item_add_subtree(ti,ett_sdp_time);
 648
 649   /* get interval */
 650   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 651   if( next_offset == -1 )
 652     return;
 653
 654   tokenlen = next_offset - offset;
 655   proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_interval, tvb,
 656                       offset, tokenlen, FALSE);
 657
 658   /* get duration */
 659   offset = next_offset + 1;
 660   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 661   if( next_offset == -1 )
 662     return;
 663
 664   tokenlen = next_offset - offset;
 665   proto_tree_add_item(sdp_repeat_time_tree,hf_repeat_time_duration, tvb,
 666                       offset, tokenlen, FALSE);
 667
 668   /* get offsets */
 669   do{
 670     offset = next_offset +1;
 671     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 672     if(next_offset != -1){
 673       tokenlen = next_offset - offset;
 674     } else {
 675       tokenlen = -1;    /* end of tvbuff */
 676     }
 677     proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_offset,
 678                         tvb, offset, tokenlen, FALSE);
 679   } while( next_offset != -1 );
 680
 681 }
 682 static void
 683 dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti){
 684   proto_tree* sdp_timezone_tree;
 685   gint offset, next_offset, tokenlen;
 686   offset = 0;
 687   next_offset = 0;
 688   tokenlen = 0;
 689
 690   sdp_timezone_tree = proto_item_add_subtree(ti,ett_sdp_timezone);
 691
 692   do{
 693     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 694     if(next_offset == -1)
 695       break;
 696     tokenlen = next_offset - offset;
 697
 698     proto_tree_add_item(sdp_timezone_tree,hf_timezone_time,tvb,
 699                         offset, tokenlen, FALSE);
 700     offset = next_offset + 1;
 701     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 702     if(next_offset != -1){
 703       tokenlen = next_offset - offset;
 704     } else {
 705       tokenlen = -1;    /* end of tvbuff */
 706     }
 707     proto_tree_add_item(sdp_timezone_tree,hf_timezone_offset,tvb,
 708                         offset, tokenlen, FALSE);
 709     offset = next_offset + 1;
 710   } while (next_offset != -1);
 711
 712 }
 713
 714
 715 static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti){
 716   proto_tree *sdp_encryption_key_tree;
 717   gint offset, next_offset, tokenlen;
 718
 719   offset = 0;
 720   next_offset = 0;
 721   tokenlen = 0;
 722
 723   sdp_encryption_key_tree = proto_item_add_subtree(ti,ett_sdp_encryption_key);
 724
 725   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 726
 727   if(next_offset == -1)
 728     return;
 729
 730   tokenlen = next_offset - offset;
 731
 732   proto_tree_add_item(sdp_encryption_key_tree,hf_encryption_key_type,
 733                       tvb, offset, tokenlen, FALSE);
 734
 735   offset = next_offset + 1;
 736   proto_tree_add_item(sdp_encryption_key_tree,hf_encryption_key_data,
 737                       tvb, offset, -1, FALSE);
 738
 739 }
 740
 741
 742
 743 static void dissect_sdp_session_attribute(tvbuff_t *tvb, proto_item * ti){
 744   proto_tree *sdp_session_attribute_tree;
 745   gint offset, next_offset, tokenlen;
 746
 747   offset = 0;
 748   next_offset = 0;
 749   tokenlen = 0;
 750
 751   sdp_session_attribute_tree = proto_item_add_subtree(ti,
 752                                                       ett_sdp_session_attribute);
 753
 754   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 755
 756   if(next_offset == -1)
 757     return;
 758
 759   tokenlen = next_offset - offset;
 760
 761   proto_tree_add_item(sdp_session_attribute_tree,
 762                       hf_session_attribute_field,
 763                       tvb, offset, tokenlen, FALSE);
 764
 765   offset = next_offset + 1;
 766   proto_tree_add_item(sdp_session_attribute_tree,
 767                       hf_session_attribute_value,
 768                       tvb, offset, -1, FALSE);
 769
 770 }
 771
 772 static void
 773 dissect_sdp_media(tvbuff_t *tvb, proto_item *ti,
 774                   transport_info_t *transport_info){
 775   proto_tree *sdp_media_tree;
 776   gint offset, next_offset, tokenlen;
 777
 778   offset = 0;
 779   next_offset = 0;
 780   tokenlen = 0;
 781
 782   sdp_media_tree = proto_item_add_subtree(ti,ett_sdp_media);
 783
 784   next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 785
 786   if(next_offset == -1)
 787     return;
 788
 789   tokenlen = next_offset - offset;
 790
 791   proto_tree_add_item(sdp_media_tree, hf_media_media, tvb,
 792                       offset, tokenlen, FALSE);
 793
 794   offset = next_offset + 1;
 795
 796   next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 797   if(next_offset == -1)
 798     return;
 799   tokenlen = next_offset - offset;
 800   next_offset = tvb_find_guint8(tvb,offset, tokenlen, '/');
 801
 802   if(next_offset != -1){
 803     tokenlen = next_offset - offset;
 804     /* Save port info */
 805     transport_info->media_port[transport_info->media_count] = tvb_get_string(tvb, offset, tokenlen);
 806
 807     proto_tree_add_item(sdp_media_tree, hf_media_port, tvb,
 808                         offset, tokenlen, FALSE);
 809     offset = next_offset + 1;
 810     next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 811     if(next_offset == -1)
 812       return;
 813     tokenlen = next_offset - offset;
 814     proto_tree_add_item(sdp_media_tree, hf_media_portcount, tvb,
 815                         offset, tokenlen, FALSE);
 816     offset = next_offset + 1;
 817   } else {
 818     next_offset = tvb_find_guint8(tvb,offset, -1, ' ');
 819
 820     if(next_offset == -1)
 821       return;
 822     tokenlen = next_offset - offset;
 823     /* Save port info */
 824     transport_info->media_port[transport_info->media_count] = tvb_get_string(tvb, offset, tokenlen);
 825
 826     /* XXX Remember Port */
 827     proto_tree_add_item(sdp_media_tree, hf_media_port, tvb,
 828                         offset, tokenlen, FALSE);
 829     offset = next_offset + 1;
 830   }
 831
 832   next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 833
 834   if( next_offset == -1)
 835     return;
 836
 837   tokenlen = next_offset - offset;
 838   /* Save port protocol */
 839   transport_info->media_proto[transport_info->media_count] = tvb_get_string(tvb, offset, tokenlen);
 840
 841   /* XXX Remember Protocol */
 842   proto_tree_add_item(sdp_media_tree, hf_media_proto, tvb,
 843                       offset, tokenlen, FALSE);
 844
 845   do{
 846     offset = next_offset + 1;
 847     next_offset = tvb_find_guint8(tvb,offset,-1,' ');
 848
 849     if(next_offset == -1){
 850       tokenlen = tvb_length_remaining(tvb, offset);     /* End of tvbuff */
 851       if (tokenlen == 0)
 852         break;  /* Nothing more left */
 853     } else {
 854       tokenlen = next_offset - offset;
 855     }
 856
 857     proto_tree_add_item(sdp_media_tree, hf_media_format, tvb,
 858                         offset, tokenlen, FALSE);
 859   } while (next_offset != -1);
 860
 861   /* Increase the count of media channels, but don't walk off the end
 862      of the arrays. */
 863   if (transport_info->media_count < (SDP_MAX_RTP_CHANNELS-1)){
 864     transport_info->media_count++;
 865   }
 866
 867   /* XXX Dissect traffic to "Port" as "Protocol"
 868    *     Remember this Port/Protocol pair so we can tear it down again later
 869    *     Actually, it's harder than that:
 870    *         We need to find out the address of the other side first and it
 871    *         looks like that info can be found in SIP headers only.
 872    */
 873
 874 }
 875
 876 static void dissect_sdp_media_attribute(tvbuff_t *tvb, proto_item * ti){
 877   proto_tree *sdp_media_attribute_tree;
 878   gint offset, next_offset, tokenlen;
 879
 880   offset = 0;
 881   next_offset = 0;
 882   tokenlen = 0;
 883
 884   sdp_media_attribute_tree = proto_item_add_subtree(ti,
 885                                                       ett_sdp_media_attribute);
 886
 887   next_offset = tvb_find_guint8(tvb,offset,-1,':');
 888
 889   if(next_offset == -1)
 890     return;
 891
 892   tokenlen = next_offset - offset;
 893
 894   proto_tree_add_item(sdp_media_attribute_tree,
 895                       hf_media_attribute_field,
 896                       tvb, offset, tokenlen, FALSE);
 897
 898   offset = next_offset + 1;
 899   proto_tree_add_item(sdp_media_attribute_tree,
 900                       hf_media_attribute_value,
 901                       tvb, offset, -1, FALSE);
 902
 903 }
 904
 905 void
 906 proto_register_sdp(void)
 907 {
 908   static hf_register_info hf[] = {
 909     { &hf_protocol_version,
 910       { "Session Description Protocol Version (v)",
 911         "sdp.version", FT_STRING, BASE_NONE,NULL,0x0,
 912         "Session Description Protocol Version", HFILL }},
 913     { &hf_owner,
 914       { "Owner/Creator, Session Id (o)",
 915         "sdp.owner", FT_STRING, BASE_NONE, NULL, 0x0,
 916         "Owner/Creator, Session Id", HFILL}},
 917     { &hf_session_name,
 918       { "Session Name (s)",
 919         "sdp.session_name", FT_STRING, BASE_NONE,NULL, 0x0,
 920         "Session Name", HFILL }},
 921     { &hf_session_info,
 922       { "Session Information (i)",
 923         "sdp.session_info", FT_STRING, BASE_NONE, NULL, 0x0,
 924         "Session Information", HFILL }},
 925     { &hf_uri,
 926       { "URI of Description (u)",
 927         "sdp.uri", FT_STRING, BASE_NONE,NULL, 0x0,
 928         "URI of Description", HFILL }},
 929     { &hf_email,
 930       { "E-mail Address (e)",
 931         "sdp.email", FT_STRING, BASE_NONE, NULL, 0x0,
 932         "E-mail Address", HFILL }},
 933     { &hf_phone,
 934       { "Phone Number (p)",
 935         "sdp.phone", FT_STRING, BASE_NONE, NULL, 0x0,
 936         "Phone Number", HFILL }},
 937     { &hf_connection_info,
 938       { "Connection Information (c)",
 939         "sdp.connection_info", FT_STRING, BASE_NONE, NULL, 0x0,
 940         "Connection Information", HFILL }},
 941     { &hf_bandwidth,
 942       { "Bandwidth Information (b)",
 943         "sdp.bandwidth", FT_STRING, BASE_NONE, NULL, 0x0,
 944         "Bandwidth Information", HFILL }},
 945     { &hf_timezone,
 946       { "Time Zone Adjustments (z)",
 947         "sdp.timezone", FT_STRING, BASE_NONE, NULL, 0x0,
 948         "Time Zone Adjustments", HFILL }},
 949     { &hf_encryption_key,
 950       { "Encryption Key (k)",
 951         "sdp.encryption_key", FT_STRING, BASE_NONE, NULL, 0x0,
 952         "Encryption Key", HFILL }},
 953     { &hf_session_attribute,
 954       { "Session Attribute (a)",
 955         "sdp.session_attr", FT_STRING, BASE_NONE, NULL, 0x0,
 956         "Session Attribute", HFILL }},
 957     { &hf_media_attribute,
 958       { "Media Attribute (a)",
 959         "sdp.media_attr", FT_STRING, BASE_NONE, NULL, 0x0,
 960         "Media Attribute", HFILL }},
 961     { &hf_time,
 962       { "Time Description, active time (t)",
 963         "sdp.time", FT_STRING, BASE_NONE, NULL, 0x0,
 964         "Time Description, active time", HFILL }},
 965     { &hf_repeat_time,
 966       { "Repeat Time (r)",
 967         "sdp.repeat_time", FT_STRING, BASE_NONE, NULL, 0x0,
 968         "Repeat Time", HFILL }},
 969     { &hf_media,
 970       { "Media Description, name and address (m)",
 971         "sdp.media", FT_STRING, BASE_NONE, NULL, 0x0,
 972         "Media Description, name and address", HFILL }},
 973     { &hf_media_title,
 974       { "Media Title (i)",
 975         "sdp.media_title",FT_STRING, BASE_NONE, NULL, 0x0,
 976         "Media Title", HFILL }},
 977     { &hf_unknown,
 978       { "Unknown",
 979         "sdp.unknown",FT_STRING, BASE_NONE, NULL, 0x0,
 980         "Unknown", HFILL }},
 981     { &hf_invalid,
 982       { "Invalid line",
 983         "sdp.invalid",FT_STRING, BASE_NONE, NULL, 0x0,
 984         "Invalid line", HFILL }},
 985     { &hf_owner_username,
 986       { "Owner Username",
 987         "sdp.owner.username",FT_STRING, BASE_NONE, NULL, 0x0,
 988         "Owner Username", HFILL }},
 989     { &hf_owner_sessionid,
 990       { "Session ID",
 991         "sdp.owner.sessionid",FT_STRING, BASE_NONE, NULL, 0x0,
 992         "Session ID", HFILL }},
 993     { &hf_owner_version,
 994       { "Session Version",
 995         "sdp.owner.version",FT_STRING, BASE_NONE, NULL, 0x0,
 996         "Session Version", HFILL }},
 997     { &hf_owner_network_type,
 998       { "Owner Network Type",
 999         "sdp.owner.network_type",FT_STRING, BASE_NONE, NULL, 0x0,
1000         "Owner Network Type", HFILL }},
1001     { &hf_owner_address_type,
1002       { "Owner Address Type",
1003         "sdp.owner.address_type",FT_STRING, BASE_NONE, NULL, 0x0,
1004         "Owner Address Type", HFILL }},
1005     { &hf_owner_address,
1006       { "Owner Address",
1007         "sdp.owner.address",FT_STRING, BASE_NONE, NULL, 0x0,
1008         "Owner Address", HFILL }},
1009     { &hf_connection_info_network_type,
1010       { "Connection Network Type",
1011         "sdp.connection_info.network_type",FT_STRING, BASE_NONE, NULL, 0x0,
1012         "Connection Network Type", HFILL }},
1013     { &hf_connection_info_address_type,
1014       { "Connection Address Type",
1015         "sdp.connection_info.address_type",FT_STRING, BASE_NONE, NULL, 0x0,
1016         "Connection Address Type", HFILL }},
1017     { &hf_connection_info_connection_address,
1018       { "Connection Address",
1019         "sdp.connection_info.address",FT_STRING, BASE_NONE, NULL, 0x0,
1020         "Connection Address", HFILL }},
1021     { &hf_connection_info_ttl,
1022       { "Connection TTL",
1023         "sdp.connection_info.ttl",FT_STRING, BASE_NONE, NULL, 0x0,
1024         "Connection TTL", HFILL }},
1025     { &hf_connection_info_num_addr,
1026       { "Connection Number of Addresses",
1027         "sdp.connection_info.num_addr",FT_STRING, BASE_NONE, NULL, 0x0,
1028         "Connection Number of Addresses", HFILL }},
1029     { &hf_bandwidth_modifier,
1030       { "Bandwidth Modifier",
1031         "sdp.bandwidth.modifier",FT_STRING, BASE_NONE, NULL, 0x0,
1032         "Bandwidth Modifier", HFILL }},
1033     { &hf_bandwidth_value,
1034       { "Bandwidth Value",
1035         "sdp.bandwidth.value",FT_STRING, BASE_NONE, NULL, 0x0,
1036         "Bandwidth Value", HFILL }},
1037     { &hf_time_start,
1038       { "Session Start Time",
1039         "sdp.time.start",FT_STRING, BASE_NONE, NULL, 0x0,
1040         "Session Start Time", HFILL }},
1041     { &hf_time_stop,
1042       { "Session Stop Time",
1043         "sdp.time.stop",FT_STRING, BASE_NONE, NULL, 0x0,
1044         "Session Stop Time", HFILL }},
1045     { &hf_repeat_time_interval,
1046       { "Repeat Interval",
1047         "sdp.repeat_time.interval",FT_STRING, BASE_NONE, NULL, 0x0,
1048         "Repeat Interval", HFILL }},
1049     { &hf_repeat_time_duration,
1050       { "Repeat Duration",
1051         "sdp.repeat_time.duration",FT_STRING, BASE_NONE, NULL, 0x0,
1052         "Repeat Duration", HFILL }},
1053     { &hf_repeat_time_offset,
1054       { "Repeat Offset",
1055         "sdp.repeat_time.offset",FT_STRING, BASE_NONE, NULL, 0x0,
1056         "Repeat Offset", HFILL }},
1057     { &hf_timezone_time,
1058       { "Timezone Time",
1059         "sdp.timezone.time",FT_STRING, BASE_NONE, NULL, 0x0,
1060         "Timezone Time", HFILL }},
1061     { &hf_timezone_offset,
1062       { "Timezone Offset",
1063         "sdp.timezone.offset",FT_STRING, BASE_NONE, NULL, 0x0,
1064         "Timezone Offset", HFILL }},
1065     { &hf_encryption_key_type,
1066       { "Key Type",
1067         "sdp.encryption_key.type",FT_STRING, BASE_NONE, NULL, 0x0,
1068         "Type", HFILL }},
1069     { &hf_encryption_key_data,
1070       { "Key Data",
1071         "sdp.encryption_key.data",FT_STRING, BASE_NONE, NULL, 0x0,
1072         "Data", HFILL }},
1073     { &hf_session_attribute_field,
1074       { "Session Attribute Fieldname",
1075         "sdp.session_attr.field",FT_STRING, BASE_NONE, NULL, 0x0,
1076         "Session Attribute Fieldname", HFILL }},
1077     { &hf_session_attribute_value,
1078       { "Session Attribute Value",
1079         "sdp.session_attr.value",FT_STRING, BASE_NONE, NULL, 0x0,
1080         "Session Attribute Value", HFILL }},
1081     { &hf_media_media,
1082       { "Media Type",
1083         "sdp.media.media",FT_STRING, BASE_NONE, NULL, 0x0,
1084         "Media Type", HFILL }},
1085     { &hf_media_port,
1086       { "Media Port",
1087         "sdp.media.port",FT_STRING, BASE_NONE, NULL, 0x0,
1088         "Media Port", HFILL }},
1089     { &hf_media_portcount,
1090       { "Media Port Count",
1091         "sdp.media.portcount",FT_STRING, BASE_NONE, NULL, 0x0,
1092         "Media Port Count", HFILL }},
1093     { &hf_media_proto,
1094       { "Media Proto",
1095         "sdp.media.proto",FT_STRING, BASE_NONE, NULL, 0x0,
1096         "Media Proto", HFILL }},
1097     { &hf_media_format,
1098       { "Media Format",
1099         "sdp.media.format",FT_STRING, BASE_NONE, NULL, 0x0,
1100         "Media Format", HFILL }},
1101     { &hf_media_attribute_field,
1102       { "Media Attribute Fieldname",
1103         "sdp.media_attribute.field",FT_STRING, BASE_NONE, NULL, 0x0,
1104         "Media Attribute Fieldname", HFILL }},
1105     { &hf_media_attribute_value,
1106       { "Media Attribute Value",
1107         "sdp.media_attribute.value",FT_STRING, BASE_NONE, NULL, 0x0,
1108         "Media Attribute Value", HFILL }},
1109
1110   };
1111   static gint *ett[] = {
1112     &ett_sdp,
1113     &ett_sdp_owner,
1114     &ett_sdp_connection_info,
1115     &ett_sdp_bandwidth,
1116     &ett_sdp_time,
1117     &ett_sdp_repeat_time,
1118     &ett_sdp_timezone,
1119     &ett_sdp_encryption_key,
1120     &ett_sdp_session_attribute,
1121     &ett_sdp_media,
1122     &ett_sdp_media_attribute,
1123   };
1124
1125   proto_sdp = proto_register_protocol("Session Description Protocol",
1126                                       "SDP", "sdp");
1127   proto_register_field_array(proto_sdp, hf, array_length(hf));
1128   proto_register_subtree_array(ett, array_length(ett));
1129
1130   /*
1131    * Register the dissector by name, so other dissectors can
1132    * grab it by name rather than just referring to it directly
1133    * (you can't refer to it directly from a plugin dissector
1134    * on Windows without stuffing it into the Big Transfer Vector).
1135    */
1136   register_dissector("sdp", dissect_sdp, proto_sdp);
1137 }
1138
1139 void
1140 proto_reg_handoff_sdp(void)
1141 {
1142   dissector_handle_t sdp_handle;
1143
1144   rtp_handle = find_dissector("rtp");
1145   rtcp_handle = find_dissector("rtcp");
1146
1147   sdp_handle = find_dissector("sdp");
1148   dissector_add_string("media_type", "application/sdp", sdp_handle);
1149 }