packet-rtp.c

   1 /* packet-rtp.c
   2  *
   3  * Routines for RTP dissection
   4  * RTP = Real time Transport Protocol
   5  *
   6  * Copyright 2000, Philips Electronics N.V.
   7  * Written by Andreas Sikkema <andreas.sikkema@philips.com>
   8  *
   9  * $Id: packet-rtp.c,v 1.38 2003/03/06 20:35:09 sahlberg Exp $
  10  *
  11  * Ethereal - Network traffic analyzer
  12  * By Gerald Combs <gerald@ethereal.com>
  13  * Copyright 1998 Gerald Combs
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version 2
  18  * of the License, or (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  28  */
  29
  30 /*
  31  * This dissector tries to dissect the RTP protocol according to Annex A
  32  * of ITU-T Recommendation H.225.0 (02/98) or RFC 1889
  33  *
  34  * RTP traffic is handled by an even UDP portnumber. This can be any
  35  * port number, but there is a registered port available, port 5004
  36  * See Annex B of ITU-T Recommendation H.225.0, section B.7
  37  *
  38  * This doesn't dissect older versions of RTP, such as:
  39  *
  40  *    the vat protocol ("version 0") - see
  41  *
  42  *      ftp://ftp.ee.lbl.gov/conferencing/vat/alpha-test/vatsrc-4.0b2.tar.gz
  43  *
  44  *    and look in "session-vat.cc" if you want to write a dissector
  45  *    (have fun - there aren't any nice header files showing the packet
  46  *    format);
  47  *
  48  *    version 1, as documented in
  49  *
  50  *      ftp://gaia.cs.umass.edu/pub/hgschulz/rtp/draft-ietf-avt-rtp-04.txt
  51  */
  52
  53
  54 #ifdef HAVE_CONFIG_H
  55 # include "config.h"
  56 #endif
  57
  58 #include <glib.h>
  59 #include <epan/packet.h>
  60
  61 #include <stdio.h>
  62 #include <string.h>
  63
  64 #include "packet-rtp.h"
  65 #include <epan/conversation.h>
  66 #include "tap.h"
  67
  68 static int rtp_tap = -1;
  69
  70 /* RTP header fields             */
  71 static int proto_rtp           = -1;
  72 static int hf_rtp_version      = -1;
  73 static int hf_rtp_padding      = -1;
  74 static int hf_rtp_extension    = -1;
  75 static int hf_rtp_csrc_count   = -1;
  76 static int hf_rtp_marker       = -1;
  77 static int hf_rtp_payload_type = -1;
  78 static int hf_rtp_seq_nr       = -1;
  79 static int hf_rtp_timestamp    = -1;
  80 static int hf_rtp_ssrc         = -1;
  81 static int hf_rtp_csrc_item    = -1;
  82 static int hf_rtp_data         = -1;
  83 static int hf_rtp_padding_data = -1;
  84 static int hf_rtp_padding_count= -1;
  85
  86 /* RTP header extension fields   */
  87 static int hf_rtp_prof_define  = -1;
  88 static int hf_rtp_length       = -1;
  89 static int hf_rtp_hdr_ext      = -1;
  90
  91 /* RTP fields defining a sub tree */
  92 static gint ett_rtp       = -1;
  93 static gint ett_csrc_list = -1;
  94 static gint ett_hdr_ext   = -1;
  95
  96 static dissector_handle_t h261_handle;
  97 static dissector_handle_t mpeg1_handle;
  98 static dissector_handle_t data_handle;
  99
 100 static gboolean dissect_rtp_heur( tvbuff_t *tvb, packet_info *pinfo,
 101     proto_tree *tree );
 102 static void dissect_rtp( tvbuff_t *tvb, packet_info *pinfo,
 103     proto_tree *tree );
 104
 105 /*
 106  * Fields in the first octet of the RTP header.
 107  */
 108
 109 /* Version is the first 2 bits of the first octet*/
 110 #define RTP_VERSION(octet)      ((octet) >> 6)
 111
 112 /* Padding is the third bit; No need to shift, because true is any value
 113    other than 0! */
 114 #define RTP_PADDING(octet)      ((octet) & 0x20)
 115
 116 /* Extension bit is the fourth bit */
 117 #define RTP_EXTENSION(octet)    ((octet) & 0x10)
 118
 119 /* CSRC count is the last four bits */
 120 #define RTP_CSRC_COUNT(octet)   ((octet) & 0xF)
 121
 122 static const value_string rtp_version_vals[] =
 123 {
 124         { 0, "Old VAT Version" },
 125         { 1, "First Draft Version" },
 126         { 2, "RFC 1889 Version" },
 127         { 0, NULL },
 128 };
 129
 130 /*
 131  * Fields in the second octet of the RTP header.
 132  */
 133
 134 /* Marker is the first bit of the second octet */
 135 #define RTP_MARKER(octet)       ((octet) & 0x80)
 136
 137 /* Payload type is the last 7 bits */
 138 #define RTP_PAYLOAD_TYPE(octet) ((octet) & 0x7F)
 139
 140 /*
 141  * RTP Payload types
 142  * Table B.2 / H.225.0
 143  * Also RFC 1890, and
 144  *
 145  *      http://www.iana.org/assignments/rtp-parameters
 146  */
 147 #define PT_PCMU         0       /* RFC 1890 */
 148 #define PT_1016         1       /* RFC 1890 */
 149 #define PT_G721         2       /* RFC 1890 */
 150 #define PT_GSM          3       /* RFC 1890 */
 151 #define PT_G723         4       /* From Vineet Kumar of Intel; see the Web page */
 152 #define PT_DVI4_8000    5       /* RFC 1890 */
 153 #define PT_DVI4_16000   6       /* RFC 1890 */
 154 #define PT_LPC          7       /* RFC 1890 */
 155 #define PT_PCMA         8       /* RFC 1890 */
 156 #define PT_G722         9       /* RFC 1890 */
 157 #define PT_L16_STEREO   10      /* RFC 1890 */
 158 #define PT_L16_MONO     11      /* RFC 1890 */
 159 #define PT_QCELP        12      /* Qualcomm Code Excited Linear Predictive coding? */
 160 #define PT_CN           13      /* RFC 3389 */
 161 #define PT_MPA          14      /* RFC 1890, RFC 2250 */
 162 #define PT_G728         15      /* RFC 1890 */
 163 #define PT_DVI4_11025   16      /* from Joseph Di Pol of Sun; see the Web page */
 164 #define PT_DVI4_22050   17      /* from Joseph Di Pol of Sun; see the Web page */
 165 #define PT_G729         18
 166 #define PT_CELB         25      /* RFC 2029 */
 167 #define PT_JPEG         26      /* RFC 2435 */
 168 #define PT_NV           28      /* RFC 1890 */
 169 #define PT_H261         31      /* RFC 2032 */
 170 #define PT_MPV          32      /* RFC 2250 */
 171 #define PT_MP2T         33      /* RFC 2250 */
 172 #define PT_H263         34      /* from Chunrong Zhu of Intel; see the Web page */
 173
 174 static const value_string rtp_payload_type_vals[] =
 175 {
 176         { PT_PCMU,      "ITU-T G.711 PCMU" },
 177         { PT_1016,      "USA Federal Standard FS-1016" },
 178         { PT_G721,      "ITU-T G.721" },
 179         { PT_GSM,       "GSM 06.10" },
 180         { PT_G723,      "ITU-T G.723" },
 181         { PT_DVI4_8000, "DVI4 8000 samples/s" },
 182         { PT_DVI4_16000, "DVI4 16000 samples/s" },
 183         { PT_LPC,       "Experimental linear predictive encoding from Xerox PARC" },
 184         { PT_PCMA,      "ITU-T G.711 PCMA" },
 185         { PT_G722,      "ITU-T G.722" },
 186         { PT_L16_STEREO, "16-bit uncompressed audio, stereo" },
 187         { PT_L16_MONO,  "16-bit uncompressed audio, monaural" },
 188         { PT_QCELP,     "Qualcomm Code Excited Linear Predictive coding" },
 189         { PT_CN,        "Comfort noise" },
 190         { PT_MPA,       "MPEG-I/II Audio"},
 191         { PT_G728,      "ITU-T G.728" },
 192         { PT_DVI4_11025, "DVI4 11025 samples/s" },
 193         { PT_DVI4_22050, "DVI4 22050 samples/s" },
 194         { PT_G729,      "ITU-T G.729" },
 195         { PT_CELB,      "Sun CellB video encoding" },
 196         { PT_JPEG,      "JPEG-compressed video" },
 197         { PT_NV,        "'nv' program" },
 198         { PT_H261,      "ITU-T H.261" },
 199         { PT_MPV,       "MPEG-I/II Video"},
 200         { PT_MP2T,      "MPEG-II transport streams"},
 201         { PT_H263,      "ITU-T H.263" },
 202         { 0,            NULL },
 203 };
 204
 205 static address fake_addr;
 206 static int heur_init = FALSE;
 207
 208 void rtp_add_address( packet_info *pinfo, const unsigned char* ip_addr,
 209     int prt )
 210 {
 211         address src_addr;
 212         conversation_t* pconv;
 213
 214         /*
 215          * If this isn't the first time this packet has been processed,
 216          * we've already done this work, so we don't need to do it
 217          * again.
 218          */
 219         if (pinfo->fd->flags.visited)
 220                 return;
 221
 222         src_addr.type = AT_IPv4;
 223         src_addr.len = 4;
 224         src_addr.data = ip_addr;
 225
 226         /*
 227          * The first time the function is called let the tcp dissector
 228          * know that we're interested in traffic
 229          */
 230         if ( ! heur_init ) {
 231                 heur_dissector_add( "udp", dissect_rtp_heur, proto_rtp );
 232                 heur_init = TRUE;
 233         }
 234
 235         /*
 236          * Check if the ip address an dport combination is not
 237          * already registered
 238          */
 239         pconv = find_conversation( &src_addr, &fake_addr, PT_UDP, prt, 0, 0 );
 240
 241         /*
 242          * If not, add
 243          * XXX - use wildcard address and port B?
 244          */
 245         if ( ! pconv ) {
 246                 pconv = conversation_new( &src_addr, &fake_addr, PT_UDP,
 247                     (guint32) prt, (guint32) 0, 0 );
 248                 conversation_add_proto_data(pconv, proto_rtp, NULL);
 249         }
 250
 251 }
 252
 253 #if 0
 254 static void rtp_init( void )
 255 {
 256         unsigned char* tmp_data;
 257         int i;
 258
 259         /* Create a fake adddress... */
 260         fake_addr.type = AT_IPv4;
 261         fake_addr.len = 4;
 262
 263         tmp_data = malloc( fake_addr.len );
 264         for ( i = 0; i < fake_addr.len; i++) {
 265                 tmp_data[i] = 0;
 266         }
 267         fake_addr.data = tmp_data;
 268 }
 269 #endif
 270
 271 static gboolean
 272 dissect_rtp_heur( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 273 {
 274         conversation_t* pconv;
 275
 276         /* This is a heuristic dissector, which means we get all the TCP
 277          * traffic not sent to a known dissector and not claimed by
 278          * a heuristic dissector called before us!
 279          * So we first check if the frame is really meant for us.
 280          */
 281         if ( ( pconv = find_conversation( &pinfo->src, &fake_addr, pinfo->ptype,
 282             pinfo->srcport, 0, 0 ) ) == NULL ) {
 283                 /*
 284                  * The source ip:port combination was not what we were
 285                  * looking for, check the destination
 286                  */
 287                 if ( ( pconv = find_conversation( &pinfo->dst, &fake_addr,
 288                     pinfo->ptype, pinfo->destport, 0, 0 ) ) == NULL ) {
 289                         return FALSE;
 290                 }
 291         }
 292
 293         /*
 294          * An RTP conversation always has a data item for RTP.
 295          * (Its existence is sufficient to indicate that this is an RTP
 296          * conversation.)
 297          */
 298         if (conversation_get_proto_data(pconv, proto_rtp) == NULL)
 299                 return FALSE;
 300
 301         dissect_rtp( tvb, pinfo, tree );
 302
 303         return TRUE;
 304 }
 305
 306 static void
 307 dissect_rtp_data( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 308     proto_tree *rtp_tree, int offset, unsigned int data_len,
 309     unsigned int data_reported_len, unsigned int payload_type )
 310 {
 311         tvbuff_t *newtvb;
 312
 313         switch( payload_type ) {
 314                 case PT_H261:
 315                         newtvb = tvb_new_subset( tvb, offset, data_len,
 316                             data_reported_len );
 317                         call_dissector(h261_handle, newtvb, pinfo, tree);
 318                         break;
 319
 320                 case PT_MPV:
 321                         newtvb = tvb_new_subset( tvb, offset, data_len,
 322                             data_reported_len );
 323                         call_dissector(mpeg1_handle, newtvb, pinfo, tree);
 324                         break;
 325
 326                 default:
 327                         proto_tree_add_item( rtp_tree, hf_rtp_data, tvb, offset, data_len, FALSE );
 328                         break;
 329         }
 330 }
 331
 332 static void
 333 dissect_rtp( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 334 {
 335         proto_item *ti            = NULL;
 336         proto_tree *rtp_tree      = NULL;
 337         proto_tree *rtp_csrc_tree = NULL;
 338         guint8      octet;
 339         unsigned int version;
 340         gboolean    padding_set;
 341         gboolean    extension_set;
 342         unsigned int csrc_count;
 343         gboolean    marker_set;
 344         unsigned int payload_type;
 345         unsigned int i            = 0;
 346         unsigned int hdr_extension= 0;
 347         unsigned int padding_count;
 348         int         data_len;
 349         unsigned int offset = 0;
 350         guint16     seq_num;
 351         guint32     timestamp;
 352         guint32     sync_src;
 353         guint32     csrc_item;
 354
 355         static struct _rtp_info rtp_info;
 356
 357         /* Get the fields in the first octet */
 358         octet = tvb_get_guint8( tvb, offset );
 359         version = RTP_VERSION( octet );
 360
 361         if (version != 2) {
 362                 /*
 363                  * Unknown or unsupported version.
 364                  */
 365                 if ( check_col( pinfo->cinfo, COL_PROTOCOL ) )   {
 366                         col_set_str( pinfo->cinfo, COL_PROTOCOL, "RTP" );
 367                 }
 368
 369                 if ( check_col( pinfo->cinfo, COL_INFO) ) {
 370                         col_add_fstr( pinfo->cinfo, COL_INFO,
 371                             "Unknown RTP version %u", version);
 372                 }
 373
 374                 if ( tree ) {
 375                         ti = proto_tree_add_item( tree, proto_rtp, tvb, offset, -1, FALSE );
 376                         rtp_tree = proto_item_add_subtree( ti, ett_rtp );
 377
 378                         proto_tree_add_uint( rtp_tree, hf_rtp_version, tvb,
 379                             offset, 1, version );
 380                 }
 381                 return;
 382         }
 383
 384         padding_set = RTP_PADDING( octet );
 385         extension_set = RTP_EXTENSION( octet );
 386         csrc_count = RTP_CSRC_COUNT( octet );
 387
 388         /* Get the fields in the second octet */
 389         octet = tvb_get_guint8( tvb, offset + 1 );
 390         marker_set = RTP_MARKER( octet );
 391         payload_type = RTP_PAYLOAD_TYPE( octet );
 392
 393         /* Get the subsequent fields */
 394         seq_num = tvb_get_ntohs( tvb, offset + 2 );
 395         timestamp = tvb_get_ntohl( tvb, offset + 4 );
 396         sync_src = tvb_get_ntohl( tvb, offset + 8 );
 397
 398         /* fill in the rtp_info structure */
 399         rtp_info.info_padding_set = padding_set;
 400         rtp_info.info_padding_count = 0;
 401         rtp_info.info_marker_set = marker_set;
 402         rtp_info.info_payload_type = payload_type;
 403         rtp_info.info_seq_num = seq_num;
 404         rtp_info.info_timestamp = timestamp;
 405         rtp_info.info_sync_src = sync_src;
 406         rtp_info.info_data_len = tvb_reported_length_remaining( tvb, offset );
 407
 408         if ( check_col( pinfo->cinfo, COL_PROTOCOL ) )   {
 409                 col_set_str( pinfo->cinfo, COL_PROTOCOL, "RTP" );
 410         }
 411
 412         if ( check_col( pinfo->cinfo, COL_INFO) ) {
 413                 col_add_fstr( pinfo->cinfo, COL_INFO,
 414                     "Payload type=%s, SSRC=%u, Seq=%u, Time=%u%s",
 415                     val_to_str( payload_type, rtp_payload_type_vals,
 416                         "Unknown (%u)" ),
 417                     sync_src,
 418                     seq_num,
 419                     timestamp,
 420                     marker_set ? ", Mark" : "");
 421         }
 422         if ( tree ) {
 423                 ti = proto_tree_add_item( tree, proto_rtp, tvb, offset, -1, FALSE );
 424                 rtp_tree = proto_item_add_subtree( ti, ett_rtp );
 425
 426                 proto_tree_add_uint( rtp_tree, hf_rtp_version, tvb,
 427                     offset, 1, version );
 428                 proto_tree_add_boolean( rtp_tree, hf_rtp_padding, tvb,
 429                     offset, 1, padding_set );
 430                 proto_tree_add_boolean( rtp_tree, hf_rtp_extension, tvb,
 431                     offset, 1, extension_set );
 432                 proto_tree_add_uint( rtp_tree, hf_rtp_csrc_count, tvb,
 433                     offset, 1, csrc_count );
 434                 offset++;
 435
 436                 proto_tree_add_boolean( rtp_tree, hf_rtp_marker, tvb, offset,
 437                     1, marker_set );
 438                 proto_tree_add_uint( rtp_tree, hf_rtp_payload_type, tvb,
 439                     offset, 1, payload_type );
 440                 offset++;
 441
 442                 /* Sequence number 16 bits (2 octets) */
 443                 proto_tree_add_uint( rtp_tree, hf_rtp_seq_nr, tvb, offset, 2, seq_num );
 444                 offset += 2;
 445
 446                 /* Timestamp 32 bits (4 octets) */
 447                 proto_tree_add_uint( rtp_tree, hf_rtp_timestamp, tvb, offset, 4, timestamp );
 448                 offset += 4;
 449
 450                 /* Synchronization source identifier 32 bits (4 octets) */
 451                 proto_tree_add_uint( rtp_tree, hf_rtp_ssrc, tvb, offset, 4, sync_src );
 452                 offset += 4;
 453
 454                 /* CSRC list*/
 455                 if ( csrc_count > 0 ) {
 456                         ti = proto_tree_add_text(rtp_tree, tvb, offset, csrc_count * 4, "Contributing Source identifiers");
 457                         rtp_csrc_tree = proto_item_add_subtree( ti, ett_csrc_list );
 458                         for (i = 0; i < csrc_count; i++ ) {
 459                                 csrc_item = tvb_get_ntohl( tvb, offset );
 460                                 proto_tree_add_uint_format( rtp_csrc_tree,
 461                                     hf_rtp_csrc_item, tvb, offset, 4,
 462                                     csrc_item,
 463                                     "CSRC item %d: %u",
 464                                     i, csrc_item );
 465                                 offset += 4;
 466                         }
 467                 }
 468
 469                 /* Optional RTP header extension */
 470                 if ( extension_set ) {
 471                         /* Defined by profile field is 16 bits (2 octets) */
 472                         proto_tree_add_uint( rtp_tree, hf_rtp_prof_define, tvb, offset, 2, tvb_get_ntohs( tvb, offset ) );
 473                         offset += 2;
 474
 475                         hdr_extension = tvb_get_ntohs( tvb, offset );
 476                         proto_tree_add_uint( rtp_tree, hf_rtp_length, tvb,
 477                             offset, 2, hdr_extension);
 478                         offset += 2;
 479                         if ( hdr_extension > 0 ) {
 480                                 ti = proto_tree_add_text(rtp_tree, tvb, offset, csrc_count * 4, "Header extensions");
 481                                 /* I'm re-using the old tree variable here
 482                                    from the CSRC list!*/
 483                                 rtp_csrc_tree = proto_item_add_subtree( ti,
 484                                     ett_hdr_ext );
 485                                 for (i = 0; i < hdr_extension; i++ ) {
 486                                         proto_tree_add_uint( rtp_csrc_tree, hf_rtp_hdr_ext, tvb, offset, 4, tvb_get_ntohl( tvb, offset ) );
 487                                         offset += 4;
 488                                 }
 489                         }
 490                 }
 491
 492                 if ( padding_set ) {
 493                         /*
 494                          * This RTP frame has padding - find it.
 495                          *
 496                          * The padding count is found in the LAST octet of
 497                          * the packet; it contains the number of octets
 498                          * that can be ignored at the end of the packet.
 499                          */
 500                         if (tvb_length(tvb) < tvb_reported_length(tvb)) {
 501                                 /*
 502                                  * We don't *have* the last octet of the
 503                                  * packet, so we can't get the padding
 504                                  * count.
 505                                  *
 506                                  * Put an indication of that into the
 507                                  * tree, and just put in a raw data
 508                                  * item.
 509                                  */
 510                                 proto_tree_add_text(rtp_tree, tvb, 0, 0,
 511                                     "Frame has padding, but not all the frame data was captured");
 512                                 call_dissector(data_handle,
 513                                     tvb_new_subset(tvb, offset, -1, -1),
 514                                     pinfo, rtp_tree);
 515                                 return;
 516                         }
 517
 518                         padding_count = tvb_get_guint8( tvb,
 519                             tvb_reported_length( tvb ) - 1 );
 520                         data_len =
 521                             tvb_reported_length_remaining( tvb, offset ) - padding_count;
 522                         if (data_len > 0) {
 523                                 /*
 524                                  * There's data left over when you take out
 525                                  * the padding; dissect it.
 526                                  */
 527                                 dissect_rtp_data( tvb, pinfo, tree, rtp_tree,
 528                                     offset,
 529                                     data_len,
 530                                     data_len,
 531                                     payload_type );
 532                                 offset += data_len;
 533                         } else if (data_len < 0) {
 534                                 /*
 535                                  * The padding count is bigger than the
 536                                  * amount of RTP payload in the packet!
 537                                  * Clip the padding count.
 538                                  *
 539                                  * XXX - put an item in the tree to indicate
 540                                  * that the padding count is bogus?
 541                                  */
 542                                 padding_count =
 543                                     tvb_reported_length_remaining(tvb, offset);
 544                         }
 545                         if (padding_count > 1) {
 546                                 /*
 547                                  * There's more than one byte of padding;
 548                                  * show all but the last byte as padding
 549                                  * data.
 550                                  */
 551                                 proto_tree_add_item( rtp_tree, hf_rtp_padding_data,
 552                                     tvb, offset, padding_count - 1, FALSE );
 553                                 offset += padding_count - 1;
 554                         }
 555                         /*
 556                          * Show the last byte in the PDU as the padding
 557                          * count.
 558                          */
 559                         proto_tree_add_item( rtp_tree, hf_rtp_padding_count,
 560                             tvb, offset, 1, FALSE );
 561                 }
 562                 else {
 563                         /*
 564                          * No padding.
 565                          */
 566                         dissect_rtp_data( tvb, pinfo, tree, rtp_tree, offset,
 567                             tvb_length_remaining( tvb, offset ),
 568                             tvb_reported_length_remaining( tvb, offset ),
 569                             payload_type );
 570                 }
 571         }
 572         tap_queue_packet(rtp_tap, pinfo, &rtp_info);
 573 }
 574
 575 void
 576 proto_register_rtp(void)
 577 {
 578         static hf_register_info hf[] =
 579         {
 580                 {
 581                         &hf_rtp_version,
 582                         {
 583                                 "Version",
 584                                 "rtp.version",
 585                                 FT_UINT8,
 586                                 BASE_DEC,
 587                                 VALS(rtp_version_vals),
 588                                 0x0,
 589                                 "", HFILL
 590                         }
 591                 },
 592                 {
 593                         &hf_rtp_padding,
 594                         {
 595                                 "Padding",
 596                                 "rtp.padding",
 597                                 FT_BOOLEAN,
 598                                 BASE_NONE,
 599                                 NULL,
 600                                 0x0,
 601                                 "", HFILL
 602                         }
 603                 },
 604                 {
 605                         &hf_rtp_extension,
 606                         {
 607                                 "Extension",
 608                                 "rtp.ext",
 609                                 FT_BOOLEAN,
 610                                 BASE_NONE,
 611                                 NULL,
 612                                 0x0,
 613                                 "", HFILL
 614                         }
 615                 },
 616                 {
 617                         &hf_rtp_csrc_count,
 618                         {
 619                                 "Contributing source identifiers count",
 620                                 "rtp.cc",
 621                                 FT_UINT8,
 622                                 BASE_DEC,
 623                                 NULL,
 624                                 0x0,
 625                                 "", HFILL
 626                         }
 627                 },
 628                 {
 629                         &hf_rtp_marker,
 630                         {
 631                                 "Marker",
 632                                 "rtp.marker",
 633                                 FT_BOOLEAN,
 634                                 BASE_NONE,
 635                                 NULL,
 636                                 0x0,
 637                                 "", HFILL
 638                         }
 639                 },
 640                 {
 641                         &hf_rtp_payload_type,
 642                         {
 643                                 "Payload type",
 644                                 "rtp.p_type",
 645                                 FT_UINT8,
 646                                 BASE_DEC,
 647                                 VALS(rtp_payload_type_vals),
 648                                 0x0,
 649                                 "", HFILL
 650                         }
 651                 },
 652                 {
 653                         &hf_rtp_seq_nr,
 654                         {
 655                                 "Sequence number",
 656                                 "rtp.seq",
 657                                 FT_UINT16,
 658                                 BASE_DEC,
 659                                 NULL,
 660                                 0x0,
 661                                 "", HFILL
 662                         }
 663                 },
 664                 {
 665                         &hf_rtp_timestamp,
 666                         {
 667                                 "Timestamp",
 668                                 "rtp.timestamp",
 669                                 FT_UINT32,
 670                                 BASE_DEC,
 671                                 NULL,
 672                                 0x0,
 673                                 "", HFILL
 674                         }
 675                 },
 676                 {
 677                         &hf_rtp_ssrc,
 678                         {
 679                                 "Synchronization Source identifier",
 680                                 "rtp.ssrc",
 681                                 FT_UINT32,
 682                                 BASE_DEC,
 683                                 NULL,
 684                                 0x0,
 685                                 "", HFILL
 686                         }
 687                 },
 688                 {
 689                         &hf_rtp_prof_define,
 690                         {
 691                                 "Defined by profile",
 692                                 "rtp.ext.profile",
 693                                 FT_UINT16,
 694                                 BASE_DEC,
 695                                 NULL,
 696                                 0x0,
 697                                 "", HFILL
 698                         }
 699                 },
 700                 {
 701                         &hf_rtp_length,
 702                         {
 703                                 "Extension length",
 704                                 "rtp.ext.len",
 705                                 FT_UINT16,
 706                                 BASE_DEC,
 707                                 NULL,
 708                                 0x0,
 709                                 "", HFILL
 710                         }
 711                 },
 712                 {
 713                         &hf_rtp_csrc_item,
 714                         {
 715                                 "CSRC item",
 716                                 "rtp.csrc.item",
 717                                 FT_UINT32,
 718                                 BASE_DEC,
 719                                 NULL,
 720                                 0x0,
 721                                 "", HFILL
 722                         }
 723                 },
 724                 {
 725                         &hf_rtp_hdr_ext,
 726                         {
 727                                 "Header extension",
 728                                 "rtp.hdr_ext",
 729                                 FT_UINT32,
 730                                 BASE_DEC,
 731                                 NULL,
 732                                 0x0,
 733                                 "", HFILL
 734                         }
 735                 },
 736                 {
 737                         &hf_rtp_data,
 738                         {
 739                                 "Payload",
 740                                 "rtp.payload",
 741                                 FT_BYTES,
 742                                 BASE_HEX,
 743                                 NULL,
 744                                 0x0,
 745                                 "", HFILL
 746                         }
 747                 },
 748                 {
 749                         &hf_rtp_padding_data,
 750                         {
 751                                 "Padding data",
 752                                 "rtp.padding.data",
 753                                 FT_BYTES,
 754                                 BASE_HEX,
 755                                 NULL,
 756                                 0x0,
 757                                 "", HFILL
 758                         }
 759                 },
 760                 {
 761                         &hf_rtp_padding_count,
 762                         {
 763                                 "Padding count",
 764                                 "rtp.padding.count",
 765                                 FT_UINT8,
 766                                 BASE_DEC,
 767                                 NULL,
 768                                 0x0,
 769                                 "", HFILL
 770                         }
 771                 },
 772 };
 773
 774         static gint *ett[] =
 775         {
 776                 &ett_rtp,
 777                 &ett_csrc_list,
 778                 &ett_hdr_ext,
 779         };
 780
 781
 782         proto_rtp = proto_register_protocol("Real-Time Transport Protocol",
 783             "RTP", "rtp");
 784         proto_register_field_array(proto_rtp, hf, array_length(hf));
 785         proto_register_subtree_array(ett, array_length(ett));
 786
 787         register_dissector("rtp", dissect_rtp, proto_rtp);
 788         rtp_tap = register_tap("rtp");
 789
 790 #if 0
 791         register_init_routine( &rtp_init );
 792 #endif
 793 }
 794
 795 void
 796 proto_reg_handoff_rtp(void)
 797 {
 798         dissector_handle_t rtp_handle;
 799
 800         /*
 801          * Get handles for the H.261 and MPEG-1 dissectors.
 802          */
 803         h261_handle = find_dissector("h261");
 804         mpeg1_handle = find_dissector("mpeg1");
 805         data_handle = find_dissector("data");
 806
 807         /*
 808          * Register this dissector as one that can be selected by a
 809          * UDP port number.
 810          */
 811         rtp_handle = find_dissector("rtp");
 812         dissector_add_handle("udp.port", rtp_handle);
 813 }