epan/dissectors/packet-mpeg-sect.c

   1 /* packet-mpeg-sect.c
   2  * Routines for MPEG2 (ISO/ISO 13818-1) Section dissection
   3  * Copyright 2012, Guy Martin <gmsoft@tuxicoman.be>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <glib.h>
  29
  30 #include <epan/packet.h>
  31 #include <epan/prefs.h>
  32 #include <epan/crc32-tvb.h>
  33 #include <epan/expert.h>
  34 #include <epan/dissectors/packet-mpeg-sect.h>
  35
  36 static int proto_mpeg_sect = -1;
  37 static int hf_mpeg_sect_table_id = -1;
  38 static int hf_mpeg_sect_syntax_indicator = -1;
  39 static int hf_mpeg_sect_reserved = -1;
  40 static int hf_mpeg_sect_length = -1;
  41 static int hf_mpeg_sect_crc = -1;
  42
  43 static gint ett_mpeg_sect = -1;
  44
  45 static expert_field ei_mpeg_sect_crc = EI_INIT;
  46
  47 static dissector_table_t mpeg_sect_tid_dissector_table;
  48
  49 static gboolean mpeg_sect_check_crc = FALSE;
  50
  51 #define MPEG_SECT_SYNTAX_INDICATOR_MASK 0x8000
  52 #define MPEG_SECT_RESERVED_MASK         0x7000
  53 #define MPEG_SECT_LENGTH_MASK           0x0FFF
  54
  55 /* From ISO/IEC 13818-1 */
  56 enum {
  57     TID_PAT,
  58     TID_CA,
  59     TID_PMT,
  60     TID_TS_DESC,
  61     TID_SCENE_DESC,
  62     TID_OBJECT_DESC,
  63     TID_FORBIDEN    = 0xFF
  64 };
  65
  66 /* From ETSI EN 300 468 */
  67 enum {
  68     TID_NIT       = 0x40,
  69     TID_NIT_OTHER,
  70     TID_SDT,
  71     TID_SDT_OTHER = 0x46,
  72     TID_BAT       = 0x4A,
  73     TID_EIT       = 0x4E,
  74     TID_EIT_OTHER,
  75     TID_TDT       = 0x70,
  76     TID_RST,
  77     TID_ST,
  78     TID_TOT
  79 };
  80
  81 /* From ETSI EN 301 790 */
  82 enum {
  83     TID_RMT = 0x41, /* Conflict with TID_NIT_OTHER */
  84     TID_SCT = 0xA0,
  85     TID_FCT,
  86     TID_TCT,
  87     TID_SPT,
  88     TID_CMT,
  89     TID_TBTP,
  90     TID_PCR,
  91     TID_TIM = 0xB0
  92 };
  93
  94 /* From ESTI EN 301 192 */
  95 enum {
  96     TID_DVB_MPE = 0x3E
  97 };
  98
  99 /* From OC-SP-ETV-AM 1.0-IO5 */
 100 enum {
 101     TID_ETV_EISS = 0xE0,
 102     TID_ETV_DII  = 0xE3,
 103     TID_ETV_DDB  = 0xE4
 104 };
 105
 106 /* From ETSI TS 102 899 */
 107 enum {
 108     TID_AIT = 0x74
 109 };
 110
 111
 112 static const value_string mpeg_sect_table_id_vals[] = {
 113
 114     { TID_PAT,         "Program Association Table (PAT)" },
 115     { TID_CA,          "Conditional Access (CA)" },
 116     { TID_PMT,         "Program Map Table (PMT)" },
 117     { TID_TS_DESC,     "Transport Stream Description" },
 118     { TID_SCENE_DESC,  "ISO/IEC 14496 Scene Description" },
 119     { TID_OBJECT_DESC, "ISO/IEC 14496 Object Description" },
 120     { TID_NIT,         "Network Information Table (NIT), current network" },
 121     { TID_NIT_OTHER,   "Network Information Table (NIT), other network" },
 122     { TID_SDT,         "Service Description Table (SDT), current network" },
 123     { TID_SDT_OTHER,   "Service Description (SDT), other network" },
 124     { TID_BAT,         "Bouquet Associatoin Table (BAT)" },
 125     { TID_EIT,         "Event Information Table (EIT), actual TS" },
 126     { TID_EIT_OTHER,   "Event Information Table (EIT), other TS" },
 127     { TID_TDT,         "Time and Date Table (TDT)" },
 128     { TID_RST,         "Running Status Table (RST)" },
 129     { TID_ST,          "Stuffing Table (ST)" },
 130     { TID_TOT,         "Time Offset Table (TOT)" },
 131     { TID_AIT,         "Application Information Table (AIT)" },
 132     { TID_SCT,         "Superframe Composition Table (SCT)" },
 133     { TID_FCT,         "Frame Composition Table (FCT)" },
 134     { TID_TCT,         "Time-Slot Composition Table (TCT)" },
 135     { TID_SPT,         "Satellite Position Table (SPT)" },
 136     { TID_CMT,         "Correction Message Table (CMT)" },
 137     { TID_TBTP,        "Terminal Burst Time Plan (TBTP)" },
 138     { TID_TIM,         "Terminal Information Message (TIM)" },
 139     { TID_DVB_MPE,     "DVB MultiProtocol Encapsulation (MPE)" },
 140     { TID_ETV_EISS,    "ETV Integrated Signaling Stream (EISS)" },
 141     { TID_ETV_DII,     "ETV Download Info Indication" },
 142     { TID_ETV_DDB,     "ETV Download Data Block" },
 143     { TID_FORBIDEN,    "Forbidden" },
 144     { 0, NULL }
 145 };
 146
 147 /* From packet-dvbci.c
 148    read a utc_time field in an apdu and write it to utc_time
 149    the encoding of the field is according to DVB-SI specification, section 5.2.5
 150    16bit modified julian day (MJD), 24bit 6*4bit BCD digits hhmmss
 151    return the length in bytes or -1 for error */
 152 gint
 153 packet_mpeg_sect_mjd_to_utc_time(tvbuff_t *tvb, gint offset, nstime_t *utc_time)
 154 {
 155     gint   bcd_time_offset;     /* start offset of the bcd time in the tvbuff */
 156     guint8 hour, min, sec;
 157
 158     if (!utc_time)
 159         return -1;
 160
 161     nstime_set_zero(utc_time);
 162     utc_time->secs  = (tvb_get_ntohs(tvb, offset) - 40587) * 86400;
 163     bcd_time_offset = offset+2;
 164     hour            = MPEG_SECT_BCD44_TO_DEC(tvb_get_guint8(tvb, bcd_time_offset));
 165     min             = MPEG_SECT_BCD44_TO_DEC(tvb_get_guint8(tvb, bcd_time_offset+1));
 166     sec             = MPEG_SECT_BCD44_TO_DEC(tvb_get_guint8(tvb, bcd_time_offset+2));
 167     if (hour>23 || min>59 || sec>59)
 168         return -1;
 169
 170     utc_time->secs += hour*3600 + min*60 + sec;
 171     return 5;
 172 }
 173
 174 guint
 175 packet_mpeg_sect_header(tvbuff_t *tvb, guint offset,
 176             proto_tree *tree, guint *sect_len, gboolean *ssi)
 177 {
 178     return packet_mpeg_sect_header_extra(tvb, offset, tree, sect_len,
 179                          NULL, ssi, NULL);
 180 }
 181
 182 guint
 183 packet_mpeg_sect_header_extra(tvbuff_t *tvb, guint offset, proto_tree *tree,
 184                 guint *sect_len, guint *reserved, gboolean *ssi,
 185                 proto_item **items)
 186 {
 187     guint       tmp;
 188     guint       len = 0;
 189     proto_item *pi[PACKET_MPEG_SECT_PI__SIZE];
 190     gint        i;
 191
 192     for (i = 0; i < PACKET_MPEG_SECT_PI__SIZE; i++) {
 193         pi[i] = NULL;
 194     }
 195
 196     if (tree) {
 197         pi[PACKET_MPEG_SECT_PI__TABLE_ID] =
 198             proto_tree_add_item(tree, hf_mpeg_sect_table_id,
 199                     tvb, offset + len, 1, ENC_BIG_ENDIAN);
 200     }
 201
 202     len++;
 203
 204     if (tree) {
 205         pi[PACKET_MPEG_SECT_PI__SSI] =
 206             proto_tree_add_item(tree, hf_mpeg_sect_syntax_indicator,
 207                     tvb, offset + len, 2, ENC_BIG_ENDIAN);
 208
 209         pi[PACKET_MPEG_SECT_PI__RESERVED] =
 210             proto_tree_add_item(tree, hf_mpeg_sect_reserved, tvb,
 211                     offset + len, 2, ENC_BIG_ENDIAN);
 212
 213         pi[PACKET_MPEG_SECT_PI__LENGTH] =
 214             proto_tree_add_item(tree, hf_mpeg_sect_length, tvb,
 215                     offset + len, 2, ENC_BIG_ENDIAN);
 216     }
 217
 218     tmp = tvb_get_ntohs(tvb, offset + len);
 219
 220     if (sect_len)
 221         *sect_len = MPEG_SECT_LENGTH_MASK & tmp;
 222
 223     if (reserved)
 224         *reserved = (MPEG_SECT_RESERVED_MASK & tmp) >> 12;
 225
 226     if (ssi)
 227         *ssi = (MPEG_SECT_SYNTAX_INDICATOR_MASK & tmp);
 228
 229     if (items) {
 230         for (i = 0; i < PACKET_MPEG_SECT_PI__SIZE; i++) {
 231             items[i] = pi[i];
 232         }
 233     }
 234
 235     len += 2;
 236
 237     return len;
 238 }
 239
 240
 241 guint
 242 packet_mpeg_sect_crc(tvbuff_t *tvb, packet_info *pinfo,
 243              proto_tree *tree, guint start, guint end)
 244 {
 245     guint32     crc, calculated_crc;
 246     const char *label;
 247
 248     crc = tvb_get_ntohl(tvb, end);
 249
 250     calculated_crc = crc;
 251     label = "Unverified";
 252     if (mpeg_sect_check_crc) {
 253         label = "Verified";
 254         calculated_crc = crc32_mpeg2_tvb_offset(tvb, start, end);
 255     }
 256
 257     if (calculated_crc == crc) {
 258         proto_tree_add_uint_format( tree, hf_mpeg_sect_crc, tvb,
 259             end, 4, crc, "CRC: 0x%08x [%s]", crc, label);
 260     } else {
 261         proto_item *msg_error;
 262
 263         msg_error = proto_tree_add_uint_format( tree, hf_mpeg_sect_crc, tvb,
 264                             end, 4, crc,
 265                             "CRC: 0x%08x [Failed Verification (Calculated: 0x%08x)]",
 266                             crc, calculated_crc );
 267         PROTO_ITEM_SET_GENERATED(msg_error);
 268         expert_add_info( pinfo, msg_error, &ei_mpeg_sect_crc);
 269     }
 270
 271     return 4;
 272 }
 273
 274
 275 static void
 276 dissect_mpeg_sect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 277 {
 278     gint     offset           = 0;
 279     guint    section_length   = 0;
 280     gboolean syntax_indicator = FALSE;
 281     guint8   table_id;
 282
 283     proto_item *ti;
 284     proto_tree *mpeg_sect_tree;
 285
 286     table_id = tvb_get_guint8(tvb, offset);
 287
 288     /* Check if a dissector can parse the current table */
 289     if (dissector_try_uint(mpeg_sect_tid_dissector_table, table_id, tvb, pinfo, tree))
 290         return;
 291
 292     /* If no dissector is registered, use the common one */
 293     col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPEG SECT");
 294     col_add_fstr(pinfo->cinfo, COL_INFO, "Table ID 0x%02x", table_id);
 295
 296     ti = proto_tree_add_item(tree, proto_mpeg_sect, tvb, offset, -1, ENC_NA);
 297     mpeg_sect_tree = proto_item_add_subtree(ti, ett_mpeg_sect);
 298
 299     proto_item_append_text(ti, " Table_ID=0x%02x", table_id);
 300
 301     packet_mpeg_sect_header(tvb, offset, mpeg_sect_tree,
 302                 &section_length, &syntax_indicator);
 303
 304     if (syntax_indicator)
 305         packet_mpeg_sect_crc(tvb, pinfo, mpeg_sect_tree, 0, (section_length-1));
 306 }
 307
 308
 309 void
 310 proto_register_mpeg_sect(void)
 311 {
 312     static hf_register_info hf[] = {
 313         { &hf_mpeg_sect_table_id, {
 314             "Table ID", "mpeg_sect.tid",
 315             FT_UINT8, BASE_HEX, VALS(mpeg_sect_table_id_vals), 0, NULL, HFILL
 316         } },
 317
 318         { &hf_mpeg_sect_syntax_indicator, {
 319             "Syntax indicator", "mpeg_sect.syntax_indicator",
 320             FT_UINT16, BASE_DEC, NULL, MPEG_SECT_SYNTAX_INDICATOR_MASK, NULL, HFILL
 321         } },
 322
 323         { &hf_mpeg_sect_reserved, {
 324             "Reserved", "mpeg_sect.reserved",
 325             FT_UINT16, BASE_HEX, NULL, MPEG_SECT_RESERVED_MASK, NULL, HFILL
 326         } },
 327
 328         { &hf_mpeg_sect_length, {
 329             "Length", "mpeg_sect.len",
 330             FT_UINT16, BASE_DEC, NULL, MPEG_SECT_LENGTH_MASK, NULL, HFILL
 331         } },
 332
 333         { &hf_mpeg_sect_crc, {
 334             "CRC 32", "mpeg_sect.crc",
 335             FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL
 336         } }
 337     };
 338
 339     static gint *ett[] = {
 340         &ett_mpeg_sect
 341     };
 342
 343     static ei_register_info ei[] = {
 344         { &ei_mpeg_sect_crc, { "mpeg_sect.crc.invalid", PI_CHECKSUM, PI_WARN, "Invalid CRC", EXPFILL }},
 345     };
 346
 347     module_t *mpeg_sect_module;
 348     expert_module_t* expert_mpeg_sect;
 349
 350     proto_mpeg_sect = proto_register_protocol("MPEG2 Section", "MPEG SECT", "mpeg_sect");
 351     register_dissector("mpeg_sect", dissect_mpeg_sect, proto_mpeg_sect);
 352
 353     proto_register_field_array(proto_mpeg_sect, hf, array_length(hf));
 354     proto_register_subtree_array(ett, array_length(ett));
 355     expert_mpeg_sect = expert_register_protocol(proto_mpeg_sect);
 356     expert_register_field_array(expert_mpeg_sect, ei, array_length(ei));
 357
 358     mpeg_sect_module = prefs_register_protocol(proto_mpeg_sect, NULL);
 359
 360     prefs_register_bool_preference(mpeg_sect_module,
 361         "verify_crc",
 362         "Verify the section CRC",
 363         "Whether the section dissector should verify the CRC",
 364         &mpeg_sect_check_crc);
 365
 366     mpeg_sect_tid_dissector_table = register_dissector_table("mpeg_sect.tid",
 367                                  "MPEG SECT Table ID",
 368                                  FT_UINT8, BASE_HEX);
 369
 370 }
 371
 372 /*
 373  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 374  *
 375  * Local variables:
 376  * c-basic-offset: 4
 377  * tab-width: 8
 378  * indent-tabs-mode: nil
 379  * End:
 380  *
 381  * vi: set shiftwidth=4 tabstop=8 expandtab:
 382  * :indentSize=4:tabSize=8:noTabs=true:
 383  */