epan/dissectors/packet-rfc2190.c

   1 /* packet-rfc2190.c
   2  *
   3  * Routines for RFC2190-encapsulated H.263 dissection
   4  *
   5  * Copyright 2003 Niklas Ogren <niklas.ogren@7l.se>
   6  * Seven Levels Consultants AB
   7  *
   8  * Copyright 2008 Richard van der Hoff, MX Telecom
   9  * <richardv@mxtelecom.com>
  10  *
  11  * $Id$
  12  *
  13  * Wireshark - Network traffic analyzer
  14  * By Gerald Combs <gerald@wireshark.org>
  15  * Copyright 1998 Gerald Combs
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License
  19  * as published by the Free Software Foundation; either version 2
  20  * of the License, or (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  30  */
  31
  32 /*
  33  * This dissector tries to dissect the H.263 protocol according to
  34  * RFC 2190, http://www.ietf.org/rfc/rfc2190.txt
  35  */
  36
  37 #include "config.h"
  38
  39 #include <glib.h>
  40 #include <epan/packet.h>
  41
  42 #include <epan/rtp_pt.h>
  43 #include <epan/iax2_codec_type.h>
  44
  45 #include "packet-h263.h"
  46
  47 /* H.263 header fields             */
  48 static int proto_rfc2190                = -1;
  49
  50 /* Mode A header */
  51 static int hf_rfc2190_ftype = -1;
  52 static int hf_rfc2190_pbframes = -1;
  53 static int hf_rfc2190_sbit = -1;
  54 static int hf_rfc2190_ebit = -1;
  55 static int hf_rfc2190_srcformat = -1;
  56 static int hf_rfc2190_picture_coding_type = -1;
  57 static int hf_rfc2190_unrestricted_motion_vector = -1;
  58 static int hf_rfc2190_syntax_based_arithmetic = -1;
  59 static int hf_rfc2190_advanced_prediction = -1;
  60 static int hf_rfc2190_r = -1;
  61 static int hf_rfc2190_rr = -1;
  62 static int hf_rfc2190_dbq = -1;
  63 static int hf_rfc2190_trb = -1;
  64 static int hf_rfc2190_tr = -1;
  65 /* Additional fields for Mode B or C header */
  66 static int hf_rfc2190_quant = -1;
  67 static int hf_rfc2190_gobn = -1;
  68 static int hf_rfc2190_mba = -1;
  69 static int hf_rfc2190_hmv1 = -1;
  70 static int hf_rfc2190_vmv1 = -1;
  71 static int hf_rfc2190_hmv2 = -1;
  72 static int hf_rfc2190_vmv2 = -1;
  73
  74 static gint ett_rfc2190                 = -1;
  75 static dissector_handle_t h263_handle;
  76
  77
  78 static void
  79 dissect_rfc2190( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
  80 {
  81     proto_item *ti                                      = NULL;
  82     proto_tree *rfc2190_tree            = NULL;
  83     int offset                                          = 0;
  84     unsigned int rfc2190_version        = 0;
  85     tvbuff_t *next_tvb;
  86         int hdr_len                                             = 0;
  87
  88     rfc2190_version = (tvb_get_guint8( tvb, offset ) & 0xc0 ) >> 6;
  89
  90     col_set_str(pinfo->cinfo, COL_PROTOCOL, "H.263 ");
  91
  92         /* Three formats (mode A, mode B and mode C) are defined for H.263
  93          * payload header. In mode A, an H.263 payload header of four bytes is
  94          * present before actual compressed H.263 video bitstream in a packet.
  95          * It allows fragmentation at GOB boundaries. In mode B, an eight byte
  96          * H.263 payload header is used and each packet starts at MB boundaries
  97          * without the PB-frames option. Finally, a twelve byte H.263 payload
  98          * header is defined in mode C to support fragmentation at MB boundaries
  99          * for frames that are coded with the PB-frames option.
 100          */
 101     if( rfc2190_version == 0x00) {
 102         col_append_str( pinfo->cinfo, COL_INFO, "MODE A ");
 103                 hdr_len = 4;
 104     }
 105     else if( rfc2190_version == 0x02) {
 106         col_append_str( pinfo->cinfo, COL_INFO, "MODE B ");
 107                 hdr_len = 8;
 108     }
 109     else if( rfc2190_version == 0x03) {
 110         col_append_str( pinfo->cinfo, COL_INFO, "MODE C ");
 111                 hdr_len = 12;
 112     }
 113
 114     if ( tree ) {
 115         ti = proto_tree_add_item( tree, proto_rfc2190, tvb, offset, hdr_len, ENC_NA );
 116         rfc2190_tree = proto_item_add_subtree( ti, ett_rfc2190 );
 117
 118         /* FBIT 1st octet, 1 bit */
 119                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_ftype, tvb, offset, 1, ENC_BIG_ENDIAN );
 120         /* PBIT 1st octet, 1 bit */
 121                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_pbframes, tvb, offset, 1, ENC_BIG_ENDIAN );
 122         /* SBIT 1st octet, 3 bits */
 123                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_sbit, tvb, offset, 1, ENC_BIG_ENDIAN );
 124         /* EBIT 1st octet, 3 bits */
 125                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_ebit, tvb, offset, 1, ENC_BIG_ENDIAN );
 126         offset++;
 127
 128         /* SRC 2nd octet, 3 bits */
 129                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_srcformat, tvb, offset, 1, ENC_BIG_ENDIAN );
 130
 131         if(rfc2190_version == 0x00) { /* MODE A */
 132             /* I flag, 1 bit */
 133                         proto_tree_add_bits_item(rfc2190_tree, hf_rfc2190_picture_coding_type, tvb, (offset<<3)+3, 1, ENC_BIG_ENDIAN);
 134             /* U flag, 1 bit */
 135                         proto_tree_add_bits_item(rfc2190_tree, hf_rfc2190_unrestricted_motion_vector, tvb, (offset<<3)+4, 1, ENC_BIG_ENDIAN);
 136             /* S flag, 1 bit */
 137                         proto_tree_add_bits_item(rfc2190_tree, hf_rfc2190_syntax_based_arithmetic, tvb, (offset<<3)+5, 1, ENC_BIG_ENDIAN);
 138             /* A flag, 1 bit */
 139                         proto_tree_add_bits_item(rfc2190_tree, hf_rfc2190_advanced_prediction, tvb, (offset<<3)+6, 1, ENC_BIG_ENDIAN);
 140
 141             /* Reserved 2nd octect, 1 bit + 3rd octect 3 bits */
 142             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_r, tvb, offset, 2, ( ( tvb_get_guint8( tvb, offset ) & 0x1 ) << 3 ) + ( ( tvb_get_guint8( tvb, offset + 1 ) & 0xe0 ) >> 5 ) );
 143
 144             offset++;
 145
 146             /* DBQ 3 octect, 2 bits */
 147                         proto_tree_add_item( rfc2190_tree, hf_rfc2190_dbq, tvb, offset, 1, ENC_BIG_ENDIAN );
 148             /* TRB 3 octect, 3 bits */
 149                         proto_tree_add_item( rfc2190_tree, hf_rfc2190_trb, tvb, offset, 1, ENC_BIG_ENDIAN );
 150             offset++;
 151
 152             /* TR 4 octect, 8 bits */
 153             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 154
 155             offset++;
 156
 157         } else { /* MODE B or MODE C */
 158             /* QUANT 2 octect, 5 bits */
 159             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_quant, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x1f );
 160
 161             offset++;
 162
 163             /* GOBN 3 octect, 5 bits */
 164             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_gobn, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0xf8 ) >> 3);
 165             /* MBA 3 octect, 3 bits + 4 octect 6 bits */
 166             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_mba, tvb, offset, 2, ( ( tvb_get_guint8( tvb, offset ) & 0x7 ) << 6 ) + ( ( tvb_get_guint8( tvb, offset + 1 ) & 0xfc ) >> 2 ) );
 167
 168             offset++;
 169
 170             /* Reserved 4th octect, 2 bits */
 171             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_r, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x3 ) );
 172
 173             offset++;
 174
 175             /* I flag, 1 bit */
 176             proto_tree_add_boolean( rfc2190_tree, hf_rfc2190_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 177             /* U flag, 1 bit */
 178             proto_tree_add_boolean( rfc2190_tree, hf_rfc2190_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 179             /* S flag, 1 bit */
 180             proto_tree_add_boolean( rfc2190_tree, hf_rfc2190_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x20 );
 181             /* A flag, 1 bit */
 182             proto_tree_add_boolean( rfc2190_tree, hf_rfc2190_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 183
 184             /* HMV1 5th octect, 4 bits + 6th octect 3 bits*/
 185             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_hmv1, tvb, offset, 2,( ( tvb_get_guint8( tvb, offset ) & 0xf ) << 3 ) + ( ( tvb_get_guint8( tvb, offset+1 ) & 0xe0 ) >> 5) );
 186
 187             offset++;
 188
 189             /* VMV1 6th octect, 5 bits + 7th octect 2 bits*/
 190             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_vmv1, tvb, offset, 2,( ( tvb_get_guint8( tvb, offset ) & 0x1f ) << 2 ) + ( ( tvb_get_guint8( tvb, offset+1 ) & 0xc0 ) >> 6) );
 191
 192             offset++;
 193
 194             /* HMV2 7th octect, 6 bits + 8th octect 1 bit*/
 195             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_hmv2, tvb, offset, 2,( ( tvb_get_guint8( tvb, offset ) & 0x3f ) << 1 ) + ( ( tvb_get_guint8( tvb, offset+1 ) & 0xf0 ) >> 7) );
 196
 197             offset++;
 198
 199             /* VMV2 8th octect, 7 bits*/
 200             proto_tree_add_uint( rfc2190_tree, hf_rfc2190_vmv2, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x7f );
 201
 202             offset++;
 203
 204             if(rfc2190_version == 0x03) { /* MODE C */
 205                 /* Reserved 9th to 11th octect, 8 + 8 + 3 bits */
 206                 proto_tree_add_uint( rfc2190_tree, hf_rfc2190_rr, tvb, offset, 3, ( tvb_get_guint8( tvb, offset ) << 11 ) + ( tvb_get_guint8( tvb, offset + 1 ) << 3 ) + ( ( tvb_get_guint8( tvb, offset + 2 ) & 0xe0 ) >> 5 ) );
 207
 208                 offset+=2;
 209
 210                 /* DBQ 11th octect, 2 bits */
 211                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_dbq, tvb, offset, 1, ENC_BIG_ENDIAN );
 212                 /* TRB 11th octect, 3 bits */
 213                 proto_tree_add_item( rfc2190_tree, hf_rfc2190_trb, tvb, offset, 1, ENC_BIG_ENDIAN );
 214
 215                 offset++;
 216
 217                 /* TR 12th octect, 8 bits */
 218                 proto_tree_add_uint( rfc2190_tree, hf_rfc2190_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 219
 220                 offset++;
 221             } /* end mode c */
 222         } /* end not mode a */
 223     } else {
 224         switch(rfc2190_version) {
 225             case 0x00: /* MODE A */
 226                 offset += 4;
 227                 break;
 228             case 0x01: /* MODE B */
 229                 offset += 8;
 230                 break;
 231             case 0x02: /* MODE C */
 232                 offset += 12;
 233                 break;
 234         }
 235     }
 236
 237
 238     /* The rest of the packet is the H.263 stream */
 239     next_tvb = tvb_new_subset_remaining( tvb, offset);
 240     call_dissector(h263_handle,next_tvb,pinfo,tree);
 241 }
 242
 243 void
 244 proto_reg_handoff_rfc2190(void)
 245 {
 246         dissector_handle_t rfc2190_handle;
 247
 248         rfc2190_handle = find_dissector("rfc2190");
 249         dissector_add_uint("rtp.pt", PT_H263, rfc2190_handle);
 250         dissector_add_uint("iax2.codec", AST_FORMAT_H263, rfc2190_handle);
 251
 252         h263_handle = find_dissector("h263data");
 253 }
 254
 255
 256 void
 257 proto_register_rfc2190(void)
 258 {
 259         static hf_register_info hf[] =
 260         {
 261                 {
 262                         &hf_rfc2190_ftype,
 263                         {
 264                                 "F",
 265                                 "rfc2190.ftype",
 266                                 FT_BOOLEAN,
 267                                 8,
 268                                 NULL,
 269                                 0x80,
 270                                 "Indicates the mode of the payload header (MODE A or B/C)", HFILL
 271                         }
 272                 },
 273                 {
 274                         &hf_rfc2190_pbframes,
 275                         {
 276                                 "p/b frame",
 277                                 "rfc2190.pbframes",
 278                                 FT_BOOLEAN,
 279                                 8,
 280                                 NULL,
 281                                 0x40,
 282                                 "Optional PB-frames mode as defined by H.263 (MODE C)", HFILL
 283                         }
 284                 },
 285                 {
 286                         &hf_rfc2190_sbit,
 287                         {
 288                                 "Start bit position",
 289                                 "rfc2190.sbit",
 290                                 FT_UINT8,
 291                                 BASE_DEC,
 292                                 NULL,
 293                                 0x38,
 294                                 "Start bit position specifies number of most significant bits that shall be ignored in the first data byte.", HFILL
 295                         }
 296                 },
 297                 {
 298                         &hf_rfc2190_ebit,
 299                         {
 300                                 "End bit position",
 301                                 "rfc2190.ebit",
 302                                 FT_UINT8,
 303                                 BASE_DEC,
 304                                 NULL,
 305                                 0x7,
 306                                 "End bit position specifies number of least significant bits that shall be ignored in the last data byte.", HFILL
 307                         }
 308                 },
 309                 {
 310                         &hf_rfc2190_srcformat,
 311                         {
 312                                 "SRC format",
 313                                 "rfc2190.srcformat",
 314                                 FT_UINT8,
 315                                 BASE_DEC,
 316                                 VALS(h263_srcformat_vals),
 317                                 0xe0,
 318                                 "Source format specifies the resolution of the current picture.", HFILL
 319                         }
 320                 },
 321                 {
 322                         &hf_rfc2190_picture_coding_type,
 323                         {
 324                                 "Inter-coded frame",
 325                                 "rfc2190.picture_coding_type",
 326                                 FT_BOOLEAN,
 327                                 8,
 328                                 NULL,
 329                                 0x0,
 330                                 "Picture coding type, intra-coded (false) or inter-coded (true)", HFILL
 331                         }
 332                 },
 333                 {
 334                         &hf_rfc2190_unrestricted_motion_vector,
 335                         {
 336                                 "Motion vector",
 337                                 "rfc2190.unrestricted_motion_vector",
 338                                 FT_BOOLEAN,
 339                                 8,
 340                                 NULL,
 341                                 0x0,
 342                                 "Unrestricted Motion Vector option for current picture", HFILL
 343                         }
 344                 },
 345                 {
 346                         &hf_rfc2190_syntax_based_arithmetic,
 347                         {
 348                                 "Syntax-based arithmetic coding",
 349                                 "rfc2190.syntax_based_arithmetic",
 350                                 FT_BOOLEAN,
 351                                 8,
 352                                 NULL,
 353                                 0x0,
 354                                 "Syntax-based Arithmetic Coding option for current picture", HFILL
 355                         }
 356                 },
 357                 {
 358                         &hf_rfc2190_advanced_prediction,
 359                         {
 360                                 "Advanced prediction option",
 361                                 "rfc2190.advanced_prediction",
 362                                 FT_BOOLEAN,
 363                                 8,
 364                                 NULL,
 365                                 0x0,
 366                                 "Advanced Prediction option for current picture", HFILL
 367                         }
 368                 },
 369                 {
 370                         &hf_rfc2190_dbq,
 371                         {
 372                                 "Differential quantization parameter",
 373                                 "rfc2190.dbq",
 374                                 FT_UINT8,
 375                                 BASE_DEC,
 376                                 NULL,
 377                                 0x18,
 378                                 "Differential quantization parameter used to calculate quantizer for the B frame based on quantizer for the P frame, when PB-frames option is used.", HFILL
 379                         }
 380                 },
 381                 {
 382                         &hf_rfc2190_trb,
 383                         {
 384                                 "Temporal Reference for B frames",
 385                                 "rfc2190.trb",
 386                                 FT_UINT8,
 387                                 BASE_DEC,
 388                                 NULL,
 389                                 0x07,
 390                                 "Temporal Reference for the B frame as defined by H.263", HFILL
 391                         }
 392                 },
 393                 {
 394                         &hf_rfc2190_tr,
 395                         {
 396                                 "Temporal Reference for P frames",
 397                                 "rfc2190.tr",
 398                                 FT_UINT8,
 399                                 BASE_DEC,
 400                                 NULL,
 401                                 0x0,
 402                                 "Temporal Reference for the P frame as defined by H.263", HFILL
 403                         }
 404                 },
 405                 {
 406                         &hf_rfc2190_quant,
 407                         {
 408                                 "Quantizer",
 409                                 "rfc2190.quant",
 410                                 FT_UINT8,
 411                                 BASE_DEC,
 412                                 NULL,
 413                                 0x0,
 414                                 "Quantization value for the first MB coded at the starting of the packet.", HFILL
 415                         }
 416                 },
 417                 {
 418                         &hf_rfc2190_gobn,
 419                         {
 420                                 "GOB Number",
 421                                 "rfc2190.gobn",
 422                                 FT_UINT8,
 423                                 BASE_DEC,
 424                                 NULL,
 425                                 0x0,
 426                                 "GOB number in effect at the start of the packet.", HFILL
 427                         }
 428                 },
 429                 {
 430                         &hf_rfc2190_mba,
 431                         {
 432                                 "Macroblock address",
 433                                 "rfc2190.mba",
 434                                 FT_UINT16,
 435                                 BASE_DEC,
 436                                 NULL,
 437                                 0x0,
 438                                 "The address within the GOB of the first MB in the packet, counting from zero in scan order.", HFILL
 439                         }
 440                 },
 441                 {
 442                         &hf_rfc2190_hmv1,
 443                         {
 444                                 "Horizontal motion vector 1",
 445                                 "rfc2190.hmv1",
 446                                 FT_UINT8,
 447                                 BASE_DEC,
 448                                 NULL,
 449                                 0x0,
 450                                 "Horizontal motion vector predictor for the first MB in this packet", HFILL
 451                         }
 452                 },
 453                 {
 454                         &hf_rfc2190_vmv1,
 455                         {
 456                                 "Vertical motion vector 1",
 457                                 "rfc2190.vmv1",
 458                                 FT_UINT8,
 459                                 BASE_DEC,
 460                                 NULL,
 461                                 0x0,
 462                                 "Vertical motion vector predictor for the first MB in this packet", HFILL
 463                         }
 464                 },
 465                 {
 466                         &hf_rfc2190_hmv2,
 467                         {
 468                                 "Horizontal motion vector 2",
 469                                 "rfc2190.hmv2",
 470                                 FT_UINT8,
 471                                 BASE_DEC,
 472                                 NULL,
 473                                 0x0,
 474                                 "Horizontal motion vector predictor for block number 3 in the first MB in this packet when four motion vectors are used with the advanced prediction option.", HFILL
 475                         }
 476                 },
 477                 {
 478                         &hf_rfc2190_vmv2,
 479                         {
 480                                 "Vertical motion vector 2",
 481                                 "rfc2190.vmv2",
 482                                 FT_UINT8,
 483                                 BASE_DEC,
 484                                 NULL,
 485                                 0x0,
 486                                 "Vertical motion vector predictor for block number 3 in the first MB in this packet when four motion vectors are used with the advanced prediction option.", HFILL
 487                         }
 488                 },
 489                 {
 490                         &hf_rfc2190_r,
 491                         {
 492                                 "Reserved field",
 493                                 "rfc2190.r",
 494                                 FT_UINT8,
 495                                 BASE_DEC,
 496                                 NULL,
 497                                 0x0,
 498                                 "Reserved field that should contain zeroes", HFILL
 499                         }
 500                 },
 501                 {
 502                         &hf_rfc2190_rr,
 503                         {
 504                                 "Reserved field 2",
 505                                 "rfc2190.rr",
 506                                 FT_UINT16,
 507                                 BASE_DEC,
 508                                 NULL,
 509                                 0x0,
 510                                 "Reserved field that should contain zeroes", HFILL
 511                         }
 512                 },
 513         };
 514
 515         static gint *ett[] =
 516         {
 517             &ett_rfc2190,
 518         };
 519
 520         proto_register_subtree_array(ett, array_length(ett));
 521
 522         proto_rfc2190 = proto_register_protocol("H.263 RTP Payload header (RFC2190)",
 523             "RFC2190", "rfc2190");
 524
 525         proto_register_field_array(proto_rfc2190, hf, array_length(hf));
 526         register_dissector("rfc2190", dissect_rfc2190, proto_rfc2190);
 527 }
 528