epan/dissectors/packet-lsc.c

   1 /* packet-lsc.c
   2  * Routines for Pegasus LSC packet disassembly
   3  * Copyright 2006, Sean Sheedy <seansh@users.sourceforge.net>
   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
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (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
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 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
  33 #include <packet-tcp.h>
  34
  35 /* Forward declaration we need below */
  36 void proto_reg_handoff_lsc(void);
  37
  38 #define LSC_PAUSE        0x01
  39 #define LSC_RESUME       0x02
  40 #define LSC_STATUS       0x03
  41 #define LSC_RESET        0x04
  42 #define LSC_JUMP         0x05
  43 #define LSC_PLAY         0x06
  44 #define LSC_DONE         0x40
  45 #define LSC_PAUSE_REPLY  0x81
  46 #define LSC_RESUME_REPLY 0x82
  47 #define LSC_STATUS_REPLY 0x83
  48 #define LSC_RESET_REPLY  0x84
  49 #define LSC_JUMP_REPLY   0x85
  50 #define LSC_PLAY_REPLY   0x86
  51
  52 #define isReply(o) ((o) & 0x80)
  53
  54 static const value_string op_code_vals[] = {
  55   { LSC_PAUSE,          "LSC_PAUSE" },
  56   { LSC_RESUME,         "LSC_RESUME" },
  57   { LSC_STATUS,         "LSC_STATUS" },
  58   { LSC_RESET,          "LSC_RESET" },
  59   { LSC_JUMP,           "LSC_JUMP" },
  60   { LSC_PLAY,           "LSC_PLAY" },
  61   { LSC_DONE,           "LSC_DONE" },
  62   { LSC_PAUSE_REPLY,    "LSC_PAUSE_REPLY" },
  63   { LSC_RESUME_REPLY,   "LSC_RESUME_REPLY" },
  64   { LSC_STATUS_REPLY,   "LSC_STATUS_REPLY" },
  65   { LSC_RESET_REPLY,    "LSC_RESET_REPLY" },
  66   { LSC_JUMP_REPLY,     "LSC_JUMP_REPLY" },
  67   { LSC_PLAY_REPLY,     "LSC_PLAY_REPLY" },
  68   { 0,                  NULL }
  69 };
  70
  71 #define LSC_OPCODE_LEN   3              /* Length to find op code */
  72 #define LSC_MIN_LEN      8              /* Minimum packet length */
  73 /* Length of each packet type */
  74 #define LSC_PAUSE_LEN   12
  75 #define LSC_RESUME_LEN  16
  76 #define LSC_STATUS_LEN   8
  77 #define LSC_RESET_LEN    8
  78 #define LSC_JUMP_LEN    20
  79 #define LSC_PLAY_LEN    20
  80 #define LSC_REPLY_LEN   17
  81
  82 static const value_string status_code_vals[] = {
  83   { 0x00,       "LSC_OK" },
  84   { 0x10,       "LSC_BAD_REQUEST" },
  85   { 0x11,       "LSC_BAD_STREAM" },
  86   { 0x12,       "LSC_WRONG_STATE" },
  87   { 0x13,       "LSC_UNKNOWN" },
  88   { 0x14,       "LSC_NO_PERMISSION" },
  89   { 0x15,       "LSC_BAD_PARAM" },
  90   { 0x16,       "LSC_NO_IMPLEMENT" },
  91   { 0x17,       "LSC_NO_MEMORY" },
  92   { 0x18,       "LSC_IMP_LIMIT" },
  93   { 0x19,       "LSC_TRANSIENT" },
  94   { 0x1a,       "LSC_NO_RESOURCES" },
  95   { 0x20,       "LSC_SERVER_ERROR" },
  96   { 0x21,       "LSC_SERVER_FAILURE" },
  97   { 0x30,       "LSC_BAD_SCALE" },
  98   { 0x31,       "LSC_BAD_START" },
  99   { 0x32,       "LSC_BAD_STOP" },
 100   { 0x40,       "LSC_MPEG_DELIVERY" },
 101   { 0,          NULL }
 102 };
 103
 104 static const value_string mode_vals[] = {
 105   { 0x00,       "O   - Open Mode" },
 106   { 0x01,       "P   - Pause Mode" },
 107   { 0x02,       "ST  - Search Transport" },
 108   { 0x03,       "T   - Transport" },
 109   { 0x04,       "TP  - Transport Pause" },
 110   { 0x05,       "STP - Search Transport Pause" },
 111   { 0x06,       "PST - Pause Search Transport" },
 112   { 0x07,       "EOS - End of Stream" },
 113   { 0,          NULL }
 114 };
 115
 116 /* Initialize the protocol and registered fields */
 117 static int proto_lsc = -1;
 118 static int hf_lsc_version = -1;
 119 static int hf_lsc_trans_id = -1;
 120 static int hf_lsc_op_code = -1;
 121 static int hf_lsc_status_code = -1;
 122 static int hf_lsc_stream_handle = -1;
 123 static int hf_lsc_start_npt = -1;
 124 static int hf_lsc_stop_npt = -1;
 125 static int hf_lsc_current_npt = -1;
 126 static int hf_lsc_scale_num = -1;
 127 static int hf_lsc_scale_denom = -1;
 128 static int hf_lsc_mode = -1;
 129
 130 /* Preferences */
 131 static guint global_lsc_port = 0;
 132
 133 /* Initialize the subtree pointers */
 134 static gint ett_lsc = -1;
 135
 136 /* Code to actually dissect the packets */
 137 static int
 138 dissect_lsc_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 139 {
 140   proto_item *ti;
 141   proto_tree *lsc_tree;
 142   guint8 op_code;
 143   guint32 stream;
 144   guint expected_len;
 145
 146   /* Protocol is LSC, packet summary is not yet known */
 147   col_set_str(pinfo->cinfo, COL_PROTOCOL, "LSC");
 148   col_clear(pinfo->cinfo, COL_INFO);
 149
 150   /* Too little data? */
 151   if (tvb_length(tvb) < LSC_MIN_LEN)
 152   {
 153     col_set_str(pinfo->cinfo, COL_INFO, "[Too short]");
 154     return 0;
 155   }
 156
 157   /* Get the op code */
 158   op_code = tvb_get_guint8(tvb, 2);
 159   /* And the stream handle */
 160   stream = tvb_get_ntohl(tvb, 4);
 161
 162   /* Check the data length against what we actually received */
 163   switch (op_code)
 164     {
 165       case LSC_PAUSE:
 166         expected_len = LSC_PAUSE_LEN;
 167         break;
 168       case LSC_RESUME:
 169         expected_len = LSC_RESUME_LEN;
 170         break;
 171       case LSC_STATUS:
 172         expected_len = LSC_STATUS_LEN;
 173         break;
 174       case LSC_RESET:
 175         expected_len = LSC_RESET_LEN;
 176         break;
 177       case LSC_JUMP:
 178         expected_len = LSC_JUMP_LEN;
 179         break;
 180       case LSC_PLAY:
 181         expected_len = LSC_PLAY_LEN;
 182         break;
 183       case LSC_DONE:
 184       case LSC_PAUSE_REPLY:
 185       case LSC_RESUME_REPLY:
 186       case LSC_STATUS_REPLY:
 187       case LSC_RESET_REPLY:
 188       case LSC_JUMP_REPLY:
 189       case LSC_PLAY_REPLY:
 190         expected_len = LSC_REPLY_LEN;
 191         break;
 192       default:
 193         /* Unrecognized op code */
 194         expected_len = LSC_MIN_LEN;
 195         break;
 196     }
 197
 198   /* Display the op code in the summary */
 199   col_add_fstr(pinfo->cinfo, COL_INFO, "%s, session %.8u",
 200                  val_to_str(op_code, op_code_vals, "Unknown op code (0x%x)"),
 201                  stream);
 202
 203   if (tvb_length(tvb) < expected_len)
 204     col_append_str(pinfo->cinfo, COL_INFO, " [Too short]");
 205   else if (tvb_length(tvb) > expected_len)
 206     col_append_str(pinfo->cinfo, COL_INFO, " [Too long]");
 207
 208   if (tree) {
 209     /* Create display subtree for the protocol */
 210     ti = proto_tree_add_item(tree, proto_lsc, tvb, 0, -1, ENC_NA);
 211     lsc_tree = proto_item_add_subtree(ti, ett_lsc);
 212
 213     /* Add already fetched items to the tree */
 214     proto_tree_add_uint(lsc_tree, hf_lsc_op_code, tvb, 2, 1, op_code);
 215     proto_tree_add_uint_format_value(lsc_tree, hf_lsc_stream_handle, tvb, 4, 4,
 216                                      stream, "%.8u", stream);
 217
 218     /* Add rest of LSC header */
 219     proto_tree_add_uint(lsc_tree, hf_lsc_version, tvb, 0, 1,
 220                         tvb_get_guint8(tvb, 0));
 221     proto_tree_add_uint(lsc_tree, hf_lsc_trans_id, tvb, 1, 1,
 222                         tvb_get_guint8(tvb, 1));
 223
 224     /* Only replies contain a status code */
 225     if (isReply(op_code))
 226       proto_tree_add_uint(lsc_tree, hf_lsc_status_code, tvb, 3, 1,
 227                           tvb_get_guint8(tvb, 3));
 228
 229     /* Add op code specific parts */
 230     switch (op_code)
 231       {
 232         case LSC_PAUSE:
 233           proto_tree_add_int(lsc_tree, hf_lsc_stop_npt, tvb, 8, 4,
 234                              tvb_get_ntohl(tvb, 8));
 235           break;
 236         case LSC_RESUME:
 237           proto_tree_add_int(lsc_tree, hf_lsc_start_npt, tvb, 8, 4,
 238                              tvb_get_ntohl(tvb, 8));
 239           proto_tree_add_int(lsc_tree, hf_lsc_scale_num, tvb, 12, 2,
 240                              tvb_get_ntohs(tvb, 12));
 241           proto_tree_add_uint(lsc_tree, hf_lsc_scale_denom, tvb, 14, 2,
 242                               tvb_get_ntohs(tvb, 14));
 243           break;
 244         case LSC_JUMP:
 245         case LSC_PLAY:
 246           proto_tree_add_int(lsc_tree, hf_lsc_start_npt, tvb, 8, 4,
 247                              tvb_get_ntohl(tvb, 8));
 248           proto_tree_add_int(lsc_tree, hf_lsc_stop_npt, tvb, 12, 4,
 249                              tvb_get_ntohl(tvb, 12));
 250           proto_tree_add_int(lsc_tree, hf_lsc_scale_num, tvb, 16, 2,
 251                              tvb_get_ntohs(tvb, 16));
 252           proto_tree_add_uint(lsc_tree, hf_lsc_scale_denom, tvb, 18, 2,
 253                               tvb_get_ntohs(tvb, 18));
 254           break;
 255         case LSC_DONE:
 256         case LSC_PAUSE_REPLY:
 257         case LSC_RESUME_REPLY:
 258         case LSC_STATUS_REPLY:
 259         case LSC_RESET_REPLY:
 260         case LSC_JUMP_REPLY:
 261         case LSC_PLAY_REPLY:
 262           proto_tree_add_int(lsc_tree, hf_lsc_current_npt, tvb, 8, 4,
 263                              tvb_get_ntohl(tvb, 8));
 264           proto_tree_add_int(lsc_tree, hf_lsc_scale_num, tvb, 12, 2,
 265                              tvb_get_ntohs(tvb, 12));
 266           proto_tree_add_uint(lsc_tree, hf_lsc_scale_denom, tvb, 14, 2,
 267                               tvb_get_ntohs(tvb, 14));
 268           proto_tree_add_uint(lsc_tree, hf_lsc_mode, tvb, 16, 1,
 269                               tvb_get_guint8(tvb, 16));
 270           break;
 271         default:
 272           break;
 273       }
 274   }
 275
 276   return tvb_length(tvb);
 277 }
 278
 279 /* Decode LSC over UDP */
 280 static int
 281 dissect_lsc_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
 282 {
 283   return dissect_lsc_common(tvb, pinfo, tree, data);
 284 }
 285
 286 /* Determine length of LSC message */
 287 static guint
 288 get_lsc_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
 289 {
 290   guint8 op_code;
 291   guint pdu_len;
 292
 293   /* Get the op code */
 294   op_code = tvb_get_guint8(tvb, offset + 2);
 295
 296   switch (op_code)
 297     {
 298       case LSC_PAUSE:
 299         pdu_len = LSC_PAUSE_LEN;
 300         break;
 301       case LSC_RESUME:
 302         pdu_len = LSC_RESUME_LEN;
 303         break;
 304       case LSC_STATUS:
 305         pdu_len = LSC_STATUS_LEN;
 306         break;
 307       case LSC_RESET:
 308         pdu_len = LSC_RESET_LEN;
 309         break;
 310       case LSC_JUMP:
 311         pdu_len = LSC_JUMP_LEN;
 312         break;
 313       case LSC_PLAY:
 314         pdu_len = LSC_PLAY_LEN;
 315         break;
 316       case LSC_DONE:
 317       case LSC_PAUSE_REPLY:
 318       case LSC_RESUME_REPLY:
 319       case LSC_STATUS_REPLY:
 320       case LSC_RESET_REPLY:
 321       case LSC_JUMP_REPLY:
 322       case LSC_PLAY_REPLY:
 323         pdu_len = LSC_REPLY_LEN;
 324         break;
 325       default:
 326         /* Unrecognized op code */
 327         pdu_len = LSC_OPCODE_LEN;
 328         break;
 329     }
 330
 331   return pdu_len;
 332 }
 333
 334 /* Decode LSC over TCP */
 335 static int
 336 dissect_lsc_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
 337 {
 338   tcp_dissect_pdus(tvb, pinfo, tree, TRUE, LSC_OPCODE_LEN, get_lsc_pdu_len,
 339                    dissect_lsc_common, data);
 340   return tvb_length(tvb);
 341 }
 342
 343 /* Register the protocol with Wireshark */
 344 void
 345 proto_register_lsc(void)
 346 {
 347   module_t *lsc_module;
 348
 349   /* Setup list of header fields */
 350   static hf_register_info hf[] = {
 351     { &hf_lsc_version,
 352       { "Version", "lsc.version",
 353         FT_UINT8, BASE_DEC, NULL, 0,
 354         "Version of the Pegasus LSC protocol", HFILL }
 355     },
 356     { &hf_lsc_trans_id,
 357       { "Transaction ID", "lsc.trans_id",
 358         FT_UINT8, BASE_DEC, NULL, 0,
 359         NULL, HFILL }
 360     },
 361     { &hf_lsc_op_code,
 362       { "Op Code", "lsc.op_code",
 363         FT_UINT8, BASE_HEX, VALS(op_code_vals), 0,
 364         "Operation Code", HFILL }
 365     },
 366     { &hf_lsc_status_code,
 367       { "Status Code", "lsc.status_code",
 368         FT_UINT8, BASE_HEX, VALS(status_code_vals), 0,
 369         NULL, HFILL }
 370     },
 371     { &hf_lsc_stream_handle,
 372       { "Stream Handle", "lsc.stream_handle",
 373         FT_UINT32, BASE_DEC, NULL, 0,
 374         "Stream identification handle", HFILL }
 375     },
 376     { &hf_lsc_start_npt,
 377       { "Start NPT", "lsc.start_npt",
 378         FT_INT32, BASE_DEC, NULL, 0,
 379         "Start Time (milliseconds)", HFILL }
 380     },
 381     { &hf_lsc_stop_npt,
 382       { "Stop NPT", "lsc.stop_npt",
 383         FT_INT32, BASE_DEC, NULL, 0,
 384         "Stop Time (milliseconds)", HFILL }
 385     },
 386     { &hf_lsc_current_npt,
 387       { "Current NPT", "lsc.current_npt",
 388         FT_INT32, BASE_DEC, NULL, 0,
 389         "Current Time (milliseconds)", HFILL }
 390     },
 391     { &hf_lsc_scale_num,
 392       { "Scale Numerator", "lsc.scale_num",
 393         FT_INT16, BASE_DEC, NULL, 0,
 394         NULL, HFILL }
 395     },
 396     { &hf_lsc_scale_denom,
 397       { "Scale Denominator", "lsc.scale_denum",
 398         FT_UINT16, BASE_DEC, NULL, 0,
 399         NULL, HFILL }
 400     },
 401     { &hf_lsc_mode,
 402       { "Server Mode", "lsc.mode",
 403         FT_UINT8, BASE_HEX, VALS(mode_vals), 0,
 404         "Current Server Mode", HFILL }
 405     }
 406   };
 407
 408   /* Setup protocol subtree array */
 409   static gint *ett[] = {
 410     &ett_lsc,
 411   };
 412
 413   /* Register the protocol name and description */
 414   proto_lsc = proto_register_protocol("Pegasus Lightweight Stream Control",
 415                                       "LSC", "lsc");
 416
 417   /* Required function calls to register the header fields and subtrees used */
 418   proto_register_field_array(proto_lsc, hf, array_length(hf));
 419   proto_register_subtree_array(ett, array_length(ett));
 420
 421   /* Register preferences module */
 422   lsc_module = prefs_register_protocol(proto_lsc, proto_reg_handoff_lsc);
 423
 424   /* Register preferences */
 425   prefs_register_uint_preference(lsc_module, "port",
 426                             "LSC Port",
 427                             "Set the TCP or UDP port for Pegasus LSC messages",
 428                             10, &global_lsc_port);
 429 }
 430
 431 void
 432 proto_reg_handoff_lsc(void)
 433 {
 434   static gboolean initialized = FALSE;
 435   static dissector_handle_t lsc_udp_handle;
 436   static dissector_handle_t lsc_tcp_handle;
 437   static guint saved_lsc_port;
 438
 439   if (!initialized) {
 440     lsc_udp_handle = new_create_dissector_handle(dissect_lsc_udp, proto_lsc);
 441     lsc_tcp_handle = new_create_dissector_handle(dissect_lsc_tcp, proto_lsc);
 442     dissector_add_handle("udp.port", lsc_udp_handle);   /* for 'decode-as' */
 443     dissector_add_handle("tcp.port", lsc_tcp_handle);   /* ...             */
 444     initialized = TRUE;
 445   } else {
 446     if (saved_lsc_port != 0) {
 447       dissector_delete_uint("udp.port", saved_lsc_port, lsc_udp_handle);
 448       dissector_delete_uint("tcp.port", saved_lsc_port, lsc_tcp_handle);
 449     }
 450   }
 451
 452   /* Set the port number */
 453   if (global_lsc_port != 0) {
 454     dissector_add_uint("udp.port", global_lsc_port, lsc_udp_handle);
 455     dissector_add_uint("tcp.port", global_lsc_port, lsc_tcp_handle);
 456   }
 457   saved_lsc_port = global_lsc_port;
 458 }