packet-wtp.c

   1 /* packet-wtp.c
   2  *
   3  * Routines to dissect WTP component of WAP traffic.
   4  *
   5  * $Id: packet-wtp.c,v 1.63 2004/02/28 22:56:36 guy Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * WAP dissector based on original work by Ben Fowler
  12  * Updated by Neil Hunter <neil.hunter@energis-squared.com>
  13  * WTLS support by Alexandre P. Ferreira (Splice IP)
  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 #ifdef HAVE_CONFIG_H
  31 # include "config.h"
  32 #endif
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36
  37 #ifdef NEED_SNPRINTF_H
  38 # include "snprintf.h"
  39 #endif
  40
  41 #include <string.h>
  42 #include <glib.h>
  43 #include <epan/packet.h>
  44 #include "reassemble.h"
  45 #include "packet-wap.h"
  46 #include "packet-wtp.h"
  47 #include "packet-wsp.h"
  48
  49 static const true_false_string continue_truth = {
  50     "TPI Present" ,
  51     "No TPI"
  52 };
  53
  54 static const true_false_string RID_truth = {
  55     "Re-Transmission",
  56     "First transmission"
  57 };
  58
  59 static const true_false_string TIDNew_truth = {
  60     "TID is new" ,
  61     "TID is valid"
  62 };
  63
  64 static const true_false_string tid_response_truth = {
  65     "Response" ,
  66     "Original"
  67 };
  68
  69 static const true_false_string UP_truth = {
  70     "User Acknowledgement required" ,
  71     "User Acknowledgement optional"
  72 };
  73
  74 static const true_false_string TVETOK_truth = {
  75     "True",
  76     "False"
  77 };
  78
  79 static const value_string vals_wtp_pdu_type[] = {
  80     { 0, "Not Allowed" },
  81     { 1, "Invoke" },
  82     { 2, "Result" },
  83     { 3, "Ack" },
  84     { 4, "Abort" },
  85     { 5, "Segmented Invoke" },
  86     { 6, "Segmented Result" },
  87     { 7, "Negative Ack" },
  88     { 0, NULL }
  89 };
  90
  91 static const value_string vals_transaction_trailer[] = {
  92     { 0, "Not last packet" },
  93     { 1, "Last packet of message" },
  94     { 2, "Last packet of group" },
  95     { 3, "Re-assembly not supported" },
  96     { 0, NULL }
  97 };
  98
  99 static const value_string vals_version[] = {
 100     { 0, "Current" },
 101     { 1, "Undefined" },
 102     { 2, "Undefined" },
 103     { 3, "Undefined" },
 104     { 0, NULL }
 105 };
 106
 107 static const value_string vals_abort_type[] = {
 108     { 0, "Provider" },
 109     { 1, "User (WSP)" },
 110     { 0, NULL }
 111 };
 112
 113 static const value_string vals_abort_reason_provider[] = {
 114     { 0x00, "Unknown" },
 115     { 0x01, "Protocol Error" },
 116     { 0x02, "Invalid TID" },
 117     { 0x03, "Not Implemented Class 2" },
 118     { 0x04, "Not Implemented SAR" },
 119     { 0x05, "Not Implemented User Acknowledgement" },
 120     { 0x06, "WTP Version Zero" },
 121     { 0x07, "Capacity Temporarily Exceeded" },
 122     { 0x08, "No Response" },
 123     { 0x09, "Message Too Large" },
 124     { 0x00, NULL }
 125 };
 126
 127 static const value_string vals_transaction_classes[] = {
 128     { 0x00, "Unreliable Invoke without Result" },
 129     { 0x01, "Reliable Invoke without Result" },
 130     { 0x02, "Reliable Invoke with Reliable Result" },
 131     { 0x00, NULL }
 132 };
 133
 134 static const value_string vals_tpi_type[] = {
 135     { 0x00, "Error" },
 136     { 0x01, "Info" },
 137     { 0x02, "Option" },
 138     { 0x03, "Packet sequence number" },
 139     { 0x04, "SDU boundary" },
 140     { 0x05, "Frame boundary" },
 141     { 0x00, NULL }
 142 };
 143
 144 static const value_string vals_tpi_opt[] = {
 145     { 0x01, "Maximum receive unit" },
 146     { 0x02, "Total message size" },
 147     { 0x03, "Delay transmission timer" },
 148     { 0x04, "Maximum group" },
 149     { 0x05, "Current TID" },
 150     { 0x06, "No cached TID" },
 151     { 0x00, NULL }
 152 };
 153
 154 /* File scoped variables for the protocol and registered fields */
 155 static int proto_wtp                            = HF_EMPTY;
 156
 157 /* These fields used by fixed part of header */
 158 static int hf_wtp_header_sub_pdu_size           = HF_EMPTY;
 159 static int hf_wtp_header_flag_continue          = HF_EMPTY;
 160 static int hf_wtp_header_pdu_type               = HF_EMPTY;
 161 static int hf_wtp_header_flag_Trailer           = HF_EMPTY;
 162 static int hf_wtp_header_flag_RID               = HF_EMPTY;
 163 static int hf_wtp_header_flag_TID               = HF_EMPTY;
 164 static int hf_wtp_header_flag_TID_response      = HF_EMPTY;
 165
 166 /* These fields used by Invoke packets */
 167 static int hf_wtp_header_Inv_version            = HF_EMPTY;
 168 static int hf_wtp_header_Inv_flag_TIDNew        = HF_EMPTY;
 169 static int hf_wtp_header_Inv_flag_UP            = HF_EMPTY;
 170 static int hf_wtp_header_Inv_Reserved           = HF_EMPTY;
 171 static int hf_wtp_header_Inv_TransactionClass   = HF_EMPTY;
 172
 173
 174 static int hf_wtp_header_variable_part          = HF_EMPTY;
 175 static int hf_wtp_data                          = HF_EMPTY;
 176
 177 static int hf_wtp_tpi_type                      = HF_EMPTY;
 178 static int hf_wtp_tpi_psn                       = HF_EMPTY;
 179 static int hf_wtp_tpi_opt                       = HF_EMPTY;
 180 static int hf_wtp_tpi_optval                    = HF_EMPTY;
 181 static int hf_wtp_tpi_info                      = HF_EMPTY;
 182
 183 static int hf_wtp_header_Ack_flag_TVETOK        = HF_EMPTY;
 184 static int hf_wtp_header_Abort_type             = HF_EMPTY;
 185 static int hf_wtp_header_Abort_reason_provider  = HF_EMPTY;
 186 static int hf_wtp_header_Abort_reason_user      = HF_EMPTY;
 187 static int hf_wtp_header_sequence_number        = HF_EMPTY;
 188 static int hf_wtp_header_missing_packets        = HF_EMPTY;
 189
 190 /* These fields used when reassembling WTP fragments */
 191 static int hf_wtp_fragments                     = HF_EMPTY;
 192 static int hf_wtp_fragment                      = HF_EMPTY;
 193 static int hf_wtp_fragment_overlap              = HF_EMPTY;
 194 static int hf_wtp_fragment_overlap_conflict     = HF_EMPTY;
 195 static int hf_wtp_fragment_multiple_tails       = HF_EMPTY;
 196 static int hf_wtp_fragment_too_long_fragment    = HF_EMPTY;
 197 static int hf_wtp_fragment_error                = HF_EMPTY;
 198 static int hf_wtp_reassembled_in                = HF_EMPTY;
 199
 200 /* Initialize the subtree pointers */
 201 static gint ett_wtp                             = ETT_EMPTY;
 202 static gint ett_wtp_sub_pdu_tree        = ETT_EMPTY;
 203 static gint ett_header                          = ETT_EMPTY;
 204 static gint ett_tpilist                         = ETT_EMPTY;
 205 static gint ett_wsp_fragments                   = ETT_EMPTY;
 206 static gint ett_wtp_fragment                    = ETT_EMPTY;
 207
 208 static const fragment_items wtp_frag_items = {
 209     &ett_wtp_fragment,
 210     &ett_wsp_fragments,
 211     &hf_wtp_fragments,
 212     &hf_wtp_fragment,
 213     &hf_wtp_fragment_overlap,
 214     &hf_wtp_fragment_overlap_conflict,
 215     &hf_wtp_fragment_multiple_tails,
 216     &hf_wtp_fragment_too_long_fragment,
 217     &hf_wtp_fragment_error,
 218     &hf_wtp_reassembled_in,
 219     "fragments"
 220 };
 221
 222 /* Handle for WSP dissector */
 223 static dissector_handle_t wsp_handle;
 224
 225 /*
 226  * reassembly of WSP
 227  */
 228 static GHashTable       *wtp_fragment_table = NULL;
 229
 230 static void
 231 wtp_defragment_init(void)
 232 {
 233     fragment_table_init(&wtp_fragment_table);
 234 }
 235
 236 /*
 237  * Extract some bitfields
 238  */
 239 #define pdu_type(octet)                 (((octet) >> 3) & 0x0F) /* Note pdu type must not be 0x00 */
 240 #define transaction_class(octet)        ((octet) & 0x03)        /* ......XX */
 241 #define transmission_trailer(octet)     (((octet) >> 1) & 0x01) /* ......X. */
 242
 243 static char retransmission_indicator(unsigned char octet)
 244 {
 245     switch (pdu_type(octet)) {
 246         case INVOKE:
 247         case RESULT:
 248         case ACK:
 249         case SEGMENTED_INVOKE:
 250         case SEGMENTED_RESULT:
 251         case NEGATIVE_ACK:
 252             return octet & 0x01;        /* .......X */
 253         default:
 254             return 0;
 255     }
 256 }
 257
 258 /*
 259  * dissect a TPI
 260  */
 261 static void
 262 wtp_handle_tpi(proto_tree *tree, tvbuff_t *tvb)
 263 {
 264     int                  offset = 0;
 265     unsigned char        tByte;
 266     unsigned char        tType;
 267     unsigned char        tLen;
 268     proto_item          *subTree = NULL;
 269
 270     tByte = tvb_get_guint8(tvb, offset++);
 271     tType = (tByte & 0x78) >> 3;
 272     if (tByte & 0x04)                           /* Long TPI     */
 273         tLen = tvb_get_guint8(tvb, offset++);
 274     else
 275         tLen = tByte & 0x03;
 276     subTree = proto_tree_add_uint(tree, hf_wtp_tpi_type,
 277                                   tvb, 0, tvb_length(tvb), tType);
 278     proto_item_add_subtree(subTree, ett_tpilist);
 279     switch (tType) {
 280         case 0x00:                      /* Error*/
 281             /* \todo    */
 282             break;
 283         case 0x01:                      /* Info */
 284             /* Beware, untested case here       */
 285             proto_tree_add_item(subTree, hf_wtp_tpi_info,
 286                                 tvb, offset, tLen, bo_little_endian);
 287             break;
 288         case 0x02:                      /* Option       */
 289             proto_tree_add_item(subTree, hf_wtp_tpi_opt,
 290                                 tvb, offset++, 1, bo_little_endian);
 291             proto_tree_add_item(subTree, hf_wtp_tpi_optval,
 292                                 tvb, offset, tLen - 1, bo_little_endian);
 293             break;
 294         case 0x03:                      /* PSN  */
 295             proto_tree_add_item(subTree, hf_wtp_tpi_psn,
 296                                 tvb, offset, 1, bo_little_endian);
 297             break;
 298         case 0x04:                      /* SDU boundary */
 299             /* \todo    */
 300             break;
 301         case 0x05:                      /* Frame boundary       */
 302             /* \todo    */
 303             break;
 304         default:
 305             break;
 306     }
 307 }
 308
 309 /* Code to actually dissect the packets */
 310 static void
 311 dissect_wtp_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 312 {
 313     static GString *szInfo = NULL;
 314     int         offCur          = 0; /* current offset from start of WTP data */
 315
 316     unsigned char  b0;
 317
 318     /* continuation flag */
 319     unsigned char       fCon;                   /* Continue flag        */
 320     unsigned char       fRID;                   /* Re-transmission indicator*/
 321     unsigned char       fTTR = '\0';            /* Transmission trailer */
 322     guint               cbHeader        = 0;    /* Fixed header length  */
 323     guint               vHeader         = 0;    /* Variable header length*/
 324     int                 abortType       = 0;
 325
 326     /* Set up structures we'll need to add the protocol subtree and manage it */
 327     proto_item          *ti = NULL;
 328     proto_tree          *wtp_tree = NULL;
 329
 330     char                pdut;
 331     char                clsTransaction  = ' ';
 332     int                 numMissing = 0;         /* Number of missing packets in a negative ack */
 333     int                 i;
 334     tvbuff_t            *wsp_tvb = NULL;
 335     guint8              psn = 0;                /* Packet sequence number*/
 336     guint16             TID = 0;                /* Transaction-Id       */
 337     int                 dataOffset;
 338     gint                dataLen;
 339
 340     if (szInfo == NULL)
 341         szInfo = g_string_sized_new(32);
 342
 343     b0 = tvb_get_guint8 (tvb, offCur + 0);
 344     /* Discover Concatenated PDUs */
 345     if (b0 == 0) {
 346         guint   c_fieldlen = 0;         /* Length of length-field       */
 347         guint   c_pdulen = 0;           /* Length of conc. PDU  */
 348
 349         if (tree) {
 350             ti = proto_tree_add_item(tree, proto_wtp,
 351                                     tvb, offCur, 1, bo_little_endian);
 352             wtp_tree = proto_item_add_subtree(ti, ett_wtp_sub_pdu_tree);
 353                 proto_item_append_text(ti, ", PDU concatenation");
 354         }
 355         offCur = 1;
 356         i = 1;
 357         while (offCur < (int) tvb_reported_length(tvb)) {
 358             tvbuff_t *wtp_tvb;
 359             /* The length of an embedded WTP PDU is coded as either:
 360              *  - a 7-bit value contained in one octet with highest bit == 0.
 361              *  - a 15-bit value contained in two octets (little endian)
 362              *    if the 1st octet has its highest bit == 1.
 363              * This means that this is NOT encoded as an uintvar-integer!!!
 364              */
 365             b0 = tvb_get_guint8(tvb, offCur + 0);
 366             if (b0 & 0x80) {
 367                 c_fieldlen = 2;
 368                 c_pdulen = ((b0 & 0x7f) << 8) | tvb_get_guint8(tvb, offCur + 1);
 369             } else {
 370                 c_fieldlen = 1;
 371                 c_pdulen = b0;
 372             }
 373             if (tree) {
 374                 proto_tree_add_uint(wtp_tree, hf_wtp_header_sub_pdu_size,
 375                                     tvb, offCur, c_fieldlen, c_pdulen);
 376             }
 377             if (i > 1 && check_col(pinfo->cinfo, COL_INFO)) {
 378                 col_append_str(pinfo->cinfo, COL_INFO, ", ");
 379             }
 380             /* Skip the length field for the WTP sub-tvb */
 381             wtp_tvb = tvb_new_subset(tvb, offCur + c_fieldlen, c_pdulen, c_pdulen);
 382             dissect_wtp_common(wtp_tvb, pinfo, wtp_tree);
 383             offCur += c_fieldlen + c_pdulen;
 384             i++;
 385         }
 386         if (tree) {
 387                 proto_item_append_text(ti, ", PDU count: %u", i);
 388         }
 389         return;
 390     }
 391     /* No concatenation */
 392     fCon = b0 & 0x80;
 393     fRID = retransmission_indicator(b0);
 394     pdut = pdu_type(b0);
 395
 396 #ifdef DEBUG
 397         printf("WTP packet %u: tree = %p, pdu = %s (%u) length: %u\n",
 398                         pinfo->fd->num, tree,
 399                         match_strval(pdut, vals_wtp_pdu_type), pdut, tvb_length(tvb));
 400 #endif
 401
 402     /* Develop the string to put in the Info column */
 403     g_string_sprintf(szInfo, "WTP %s",
 404                     val_to_str(pdut, vals_wtp_pdu_type, "Unknown PDU type 0x%x"));
 405
 406     switch (pdut) {
 407         case INVOKE:
 408             fTTR = transmission_trailer(b0);
 409             TID = tvb_get_ntohs(tvb, offCur + 1);
 410             psn = 0;
 411             clsTransaction = transaction_class(tvb_get_guint8(tvb, offCur + 3));
 412             g_string_sprintfa(szInfo, " Class %d", clsTransaction);
 413             cbHeader = 4;
 414             break;
 415
 416         case SEGMENTED_INVOKE:
 417         case SEGMENTED_RESULT:
 418             fTTR = transmission_trailer(b0);
 419             TID = tvb_get_ntohs(tvb, offCur + 1);
 420             psn = tvb_get_guint8(tvb, offCur + 3);
 421             if (psn != 0)
 422                 g_string_sprintfa(szInfo, " (%u)", psn);
 423             cbHeader = 4;
 424             break;
 425
 426         case ABORT:
 427             cbHeader = 4;
 428             break;
 429
 430         case RESULT:
 431             fTTR = transmission_trailer(b0);
 432             TID = tvb_get_ntohs(tvb, offCur + 1);
 433             psn = 0;
 434             cbHeader = 3;
 435             break;
 436
 437         case ACK:
 438             cbHeader = 3;
 439             break;
 440
 441         case NEGATIVE_ACK:
 442             /* Variable number of missing packets */
 443             numMissing = tvb_get_guint8(tvb, offCur + 3);
 444             cbHeader = numMissing + 4;
 445             break;
 446
 447         default:
 448             break;
 449     };
 450     if (fRID) {
 451         g_string_append( szInfo, " R" );
 452     };
 453     /* In the interest of speed, if "tree" is NULL, don't do any work not
 454        necessary to generate protocol tree items. */
 455     if (tree) {
 456 #ifdef DEBUG
 457         fprintf(stderr, "dissect_wtp: cbHeader = %d\n", cbHeader);
 458 #endif
 459         /* NOTE - Length will be set when we process the TPI */
 460         ti = proto_tree_add_item(tree, proto_wtp, tvb, offCur, 0, bo_little_endian);
 461 #ifdef DEBUG
 462         fprintf(stderr, "dissect_wtp: (7) Returned from proto_tree_add_item\n");
 463 #endif
 464         wtp_tree = proto_item_add_subtree(ti, ett_wtp);
 465
 466 /* Code to process the packet goes here */
 467 #ifdef DEBUG
 468         fprintf(stderr, "dissect_wtp: cbHeader = %d\n", cbHeader);
 469         fprintf(stderr, "dissect_wtp: offCur = %d\n", offCur);
 470 #endif
 471         /* Add common items: only CON and PDU Type */
 472         proto_tree_add_item(
 473                         wtp_tree,                       /* tree */
 474                         hf_wtp_header_flag_continue,    /* id */
 475                         tvb,
 476                         offCur,                         /* start of highlight */
 477                         1,                              /* length of highlight*/
 478                         b0                              /* value */
 479              );
 480         proto_tree_add_item(wtp_tree, hf_wtp_header_pdu_type, tvb, offCur, 1, bo_little_endian);
 481
 482         switch(pdut) {
 483             case INVOKE:
 484                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, bo_little_endian);
 485                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, bo_little_endian);
 486                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 487                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 488
 489                 proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_version , tvb, offCur + 3, 1, bo_little_endian);
 490                 proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_flag_TIDNew, tvb, offCur + 3, 1, bo_little_endian);
 491                 proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_flag_UP, tvb, offCur + 3, 1, bo_little_endian);
 492                 proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_Reserved, tvb, offCur + 3, 1, bo_little_endian);
 493                 proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_TransactionClass, tvb, offCur + 3, 1, bo_little_endian);
 494                 proto_item_append_text(ti,
 495                                 ", PDU: Invoke (%u)"
 496                                 ", Transaction Class: %s (%u)",
 497                                 INVOKE,
 498                                 match_strval(clsTransaction, vals_transaction_classes),
 499                                 clsTransaction);
 500                 break;
 501
 502             case RESULT:
 503                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, bo_little_endian);
 504                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, bo_little_endian);
 505                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 506                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 507                 proto_item_append_text(ti, ", PDU: Result (%u)", RESULT);
 508                 break;
 509
 510             case ACK:
 511                 proto_tree_add_item(wtp_tree, hf_wtp_header_Ack_flag_TVETOK, tvb, offCur, 1, bo_big_endian);
 512
 513                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, bo_little_endian);
 514                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 515                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 516                 proto_item_append_text(ti, ", PDU: ACK (%u)", ACK);
 517                 break;
 518
 519             case ABORT:
 520                 abortType = tvb_get_guint8 (tvb, offCur) & 0x07;
 521                 proto_tree_add_item(wtp_tree, hf_wtp_header_Abort_type , tvb, offCur , 1, bo_little_endian);
 522                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 523                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 524
 525                 if (abortType == PROVIDER)
 526                 {
 527                         guint8 reason = tvb_get_guint8(tvb, offCur + 3);
 528                     proto_tree_add_item( wtp_tree, hf_wtp_header_Abort_reason_provider , tvb, offCur + 3 , 1, bo_little_endian);
 529                         proto_item_append_text(ti,
 530                                         ", PDU: Abort (%u)"
 531                                         ", Type: Provider (%u)"
 532                                         ", Reason: %s (%u)",
 533                                         ABORT,
 534                                         PROVIDER,
 535                                         match_strval(reason, vals_abort_reason_provider),
 536                                         reason);
 537                 }
 538                 else if (abortType == USER)
 539                 {
 540                         guint8 reason = tvb_get_guint8(tvb, offCur + 3);
 541                     proto_tree_add_item(wtp_tree, hf_wtp_header_Abort_reason_user , tvb, offCur + 3 , 1, bo_little_endian);
 542                         proto_item_append_text(ti,
 543                                         ", PDU: Abort (%u)"
 544                                         ", Type: User (%u)"
 545                                         ", Reason: %s (%u)",
 546                                         ABORT,
 547                                         PROVIDER,
 548                                         match_strval(reason, vals_wsp_reason_codes),
 549                                         reason);
 550                 }
 551                 break;
 552
 553             case SEGMENTED_INVOKE:
 554                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, bo_little_endian);
 555                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, bo_little_endian);
 556                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 557                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 558
 559                 proto_tree_add_item(wtp_tree, hf_wtp_header_sequence_number , tvb, offCur + 3, 1, bo_little_endian);
 560                 proto_item_append_text(ti,
 561                                 ", PDU: Segmented Invoke (%u)"
 562                                 ", Packet Sequence Number: %u",
 563                                 SEGMENTED_INVOKE, psn);
 564                 break;
 565
 566             case SEGMENTED_RESULT:
 567                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, bo_little_endian);
 568                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, bo_little_endian);
 569                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 570                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 571
 572                 proto_tree_add_item(wtp_tree, hf_wtp_header_sequence_number , tvb, offCur + 3, 1, bo_little_endian);
 573                 proto_item_append_text(ti,
 574                                 ", PDU: Segmented Result (%u)"
 575                                 ", Packet Sequence Number: %u",
 576                                 SEGMENTED_RESULT, psn);
 577                 break;
 578
 579             case NEGATIVE_ACK:
 580                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, bo_little_endian);
 581                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, bo_big_endian);
 582                 proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, bo_big_endian);
 583
 584                 proto_tree_add_item(wtp_tree, hf_wtp_header_missing_packets , tvb, offCur + 3, 1, bo_little_endian);
 585                 /* Iterate through missing packets */
 586                 for (i = 0; i < numMissing; i++)
 587                 {
 588                     proto_tree_add_item(wtp_tree, hf_wtp_header_sequence_number, tvb, offCur + 4 + i, 1, bo_little_endian);
 589                 }
 590                 proto_item_append_text(ti,
 591                                 ", PDU: Negative Ack (%u)"
 592                                 ", Missing Packets: %u",
 593                                 NEGATIVE_ACK, numMissing);
 594                 break;
 595
 596             default:
 597                 break;
 598         };
 599         if (fRID) {
 600                 proto_item_append_text(ti, ", Retransmission");
 601         }
 602     } else { /* tree is NULL */
 603 #ifdef DEBUG
 604         fprintf(stderr, "dissect_wtp: (4) tree was %p\n", tree);
 605 #endif
 606     }
 607         /* Process the variable part */
 608         if (fCon) {                     /* Now, analyze variable part   */
 609             unsigned char        tCon;
 610             unsigned char        tByte;
 611             unsigned char        tpiLen;
 612             tvbuff_t            *tmp_tvb;
 613
 614             vHeader = 0;                /* Start scan all over  */
 615
 616             do {
 617                 tByte = tvb_get_guint8(tvb, offCur + cbHeader + vHeader);
 618                 tCon = tByte & 0x80;
 619                 if (tByte & 0x04)       /* Long TPI     */
 620                     tpiLen = 2 + tvb_get_guint8(tvb,
 621                                             offCur + cbHeader + vHeader + 1);
 622                 else
 623                     tpiLen = 1 + (tByte & 0x03);
 624                 if (tree)
 625                 {
 626                 tmp_tvb = tvb_new_subset(tvb, offCur + cbHeader + vHeader,
 627                                         tpiLen, tpiLen);
 628                 wtp_handle_tpi(wtp_tree, tmp_tvb);
 629                 }
 630                 vHeader += tpiLen;
 631             } while (tCon);
 632         } else {
 633                 /* There is no variable part */
 634         }       /* End of variable part of header */
 635
 636         /* Set the length of the WTP protocol part now we know the length of the
 637          * fixed and variable WTP headers */
 638         if (tree)
 639         proto_item_set_len(ti, cbHeader + vHeader);
 640
 641 #ifdef DEBUG
 642     fprintf( stderr, "dissect_wtp: cbHeader = %d\n", cbHeader );
 643 #endif
 644
 645     /*
 646      * Any remaining data ought to be WSP data (if not WTP ACK, NACK
 647      * or ABORT pdu), so, if we have any remaining data, and it's
 648      * not an ACK, NACK, or ABORT PDU, hand it off (defragmented) to the
 649      * WSP dissector.
 650      * Note that the last packet of a fragmented WTP message needn't
 651      * contain any data, so we allow payloadless packets to be
 652      * reassembled.  (XXX - does the reassembly code handle this
 653      * for packets other than the last packet?)
 654      *
 655          * Try calling a subdissector only if:
 656          *      - The WTP payload is ressembled in this very packet,
 657          *      - The WTP payload is not fragmented across packets.
 658          */
 659     dataOffset = offCur + cbHeader + vHeader;
 660     dataLen = tvb_reported_length_remaining(tvb, dataOffset);
 661     if ((dataLen >= 0) &&
 662                         ! ((pdut==ACK) || (pdut==NEGATIVE_ACK) || (pdut==ABORT)))
 663     {
 664                 /* Try to reassemble if needed, and hand over to WSP
 665                  * A fragmented WTP packet is either:
 666                  *      - An INVOKE with fTTR (transmission trailer) not set,
 667                  *      - a SEGMENTED_INVOKE,
 668                  *      - A RESULT with fTTR (transmission trailer) not set,
 669                  *      - a SEGMENTED_RESULT.
 670                  */
 671                 if ( ( (pdut == SEGMENTED_INVOKE) || (pdut == SEGMENTED_RESULT)
 672                                 || ( ((pdut == INVOKE) || (pdut == RESULT)) && (!fTTR) )
 673                         ) && tvb_bytes_exist(tvb, dataOffset, dataLen) )
 674                 {
 675                         /* Try reassembling fragments */
 676                         fragment_data *fd_wtp = NULL;
 677                         guint32 reassembled_in = 0;
 678                         gboolean save_fragmented = pinfo->fragmented;
 679
 680                         pinfo->fragmented = TRUE;
 681                         fd_wtp = fragment_add_seq(tvb, dataOffset, pinfo, TID,
 682                                         wtp_fragment_table, psn, dataLen, !fTTR);
 683                         /* XXX - fragment_add_seq() yields NULL unless Ethereal knows
 684                          * that the packet is part of a reassembled whole. This means
 685                          * that fd_wtp will be NULL as long as Ethereal did not encounter
 686                          * (and process) the packet containing the last fragment.
 687                          * This implies that Ethereal needs two passes over the data for
 688                          * correct reassembly. At the first pass, a capture containing
 689                          * three fragments plus a retransmssion of the last fragment
 690                          * will progressively show:
 691                          *
 692                          *              Packet 1: (Unreassembled fragment 1)
 693                          *              Packet 2: (Unreassembled fragment 2)
 694                          *              Packet 3: (Reassembled WTP)
 695                          *              Packet 4: (WTP payload reassembled in packet 3)
 696                          *
 697                          * However at subsequent evaluation (e.g., by applying a display
 698                          * filter) the packet summary will show:
 699                          *
 700                          *              Packet 1: (WTP payload reassembled in packet 3)
 701                          *              Packet 2: (WTP payload reassembled in packet 3)
 702                          *              Packet 3: (Reassembled WTP)
 703                          *              Packet 4: (WTP payload reassembled in packet 3)
 704                          *
 705                          * This is important to know, and also affects read filters!
 706                          */
 707                         wsp_tvb = process_reassembled_data(tvb, dataOffset, pinfo,
 708                                         "Reassembled WTP", fd_wtp, &wtp_frag_items,
 709                                         NULL, wtp_tree);
 710 #ifdef DEBUG
 711                         printf("WTP: Packet %u %s -> %d: wsp_tvb = %p, fd_wtp = %p, frame = %u\n",
 712                                         pinfo->fd->num,
 713                                         fd_wtp ? "Reassembled" : "Not reassembled",
 714                                         fd_wtp ? fd_wtp->reassembled_in : -1,
 715                                         wsp_tvb,
 716                                         fd_wtp
 717                                         );
 718 #endif
 719                         if (fd_wtp) {
 720                                 /* Reassembled */
 721                                 reassembled_in = fd_wtp->reassembled_in;
 722                                 if (pinfo->fd->num == reassembled_in) {
 723                                         /* Reassembled in this very packet:
 724                                          * We can safely hand the tvb to the WSP dissector */
 725                                         call_dissector(wsp_handle, wsp_tvb, pinfo, tree);
 726                                 } else {
 727                                         /* Not reassembled in this packet */
 728                                         if (check_col(pinfo->cinfo, COL_INFO)) {
 729                                                 col_append_fstr(pinfo->cinfo, COL_INFO,
 730                                                                 "%s (WTP payload reassembled in packet %u)",
 731                                                                 szInfo->str, fd_wtp->reassembled_in);
 732                                         }
 733                                         if (tree) {
 734                                                 proto_tree_add_text(wtp_tree, tvb, dataOffset, -1,
 735                                                                 "Payload");
 736                                         }
 737                                 }
 738                         } else {
 739                                 /* Not reassembled yet, or not reassembled at all */
 740                                 if (check_col(pinfo->cinfo, COL_INFO)) {
 741                                         col_append_fstr(pinfo->cinfo, COL_INFO,
 742                                                                 "%s (Unreassembled fragment %u)",
 743                                                                 szInfo->str, psn);
 744                                 }
 745                                 if (tree) {
 746                                         proto_tree_add_text(wtp_tree, tvb, dataOffset, -1,
 747                                                         "Payload");
 748                                 }
 749                         }
 750                         /* Now reset fragmentation information in pinfo */
 751                         pinfo->fragmented = save_fragmented;
 752                 }
 753                 else if ( ((pdut == INVOKE) || (pdut == RESULT)) && (fTTR) )
 754                 {
 755                         /* Non-fragmented payload */
 756                         wsp_tvb = tvb_new_subset(tvb, dataOffset, -1, -1);
 757                         /* We can safely hand the tvb to the WSP dissector */
 758                         call_dissector(wsp_handle, wsp_tvb, pinfo, tree);
 759                 }
 760                 else
 761                 {
 762                         /* Nothing to hand to subdissector */
 763                         if (check_col(pinfo->cinfo, COL_INFO))
 764                                 col_append_str(pinfo->cinfo, COL_INFO, szInfo->str);
 765                 }
 766         }
 767         else
 768         {
 769                 /* Nothing to hand to subdissector */
 770                 if (check_col(pinfo->cinfo, COL_INFO))
 771                         col_append_str(pinfo->cinfo, COL_INFO, szInfo->str);
 772         }
 773 }
 774
 775 /*
 776  * Called directly from UDP.
 777  * Put "WTP+WSP" into the "Protocol" column.
 778  */
 779 static void
 780 dissect_wtp_fromudp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 781 {
 782     if (check_col(pinfo->cinfo, COL_PROTOCOL))
 783         col_set_str(pinfo->cinfo, COL_PROTOCOL, "WTP+WSP" );
 784     if (check_col(pinfo->cinfo, COL_INFO))
 785         col_clear(pinfo->cinfo, COL_INFO);
 786
 787     dissect_wtp_common(tvb, pinfo, tree);
 788 }
 789
 790 /*
 791  * Called from a higher-level WAP dissector, presumably WTLS.
 792  * Put "WTLS+WSP+WTP" to the "Protocol" column.
 793  *
 794  * XXX - is this supposed to be called from WTLS?  If so, we're not
 795  * calling it....
 796  *
 797  * XXX - can this be called from any other dissector?
 798  */
 799 static void
 800 dissect_wtp_fromwtls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 801 {
 802     if (check_col(pinfo->cinfo, COL_PROTOCOL))
 803         col_set_str(pinfo->cinfo, COL_PROTOCOL, "WTLS+WTP+WSP" );
 804     if (check_col(pinfo->cinfo, COL_INFO))
 805         col_clear(pinfo->cinfo, COL_INFO);
 806
 807     dissect_wtp_common(tvb, pinfo, tree);
 808 }
 809
 810 /* Register the protocol with Ethereal */
 811 void
 812 proto_register_wtp(void)
 813 {
 814
 815     /* Setup list of header fields */
 816     static hf_register_info hf[] = {
 817         { &hf_wtp_header_sub_pdu_size,
 818             {   "Sub PDU size",
 819                 "wtp.sub_pdu_size",
 820                 FT_UINT16, BASE_DEC, NULL, 0x0,
 821                 "Size of Sub-PDU (bytes)", HFILL
 822             }
 823         },
 824         { &hf_wtp_header_flag_continue,
 825             {   "Continue Flag",
 826                 "wtp.continue_flag",
 827                 FT_BOOLEAN, 8, TFS( &continue_truth ), 0x80,
 828                 "Continue Flag", HFILL
 829             }
 830         },
 831         { &hf_wtp_header_pdu_type,
 832             {   "PDU Type",
 833                 "wtp.pdu_type",
 834                 FT_UINT8, BASE_HEX, VALS( vals_wtp_pdu_type ), 0x78,
 835                 "PDU Type", HFILL
 836             }
 837         },
 838         { &hf_wtp_header_flag_Trailer,
 839             {   "Trailer Flags",
 840                 "wtp.trailer_flags",
 841                 FT_UINT8, BASE_HEX, VALS( vals_transaction_trailer ), 0x06,
 842                 "Trailer Flags", HFILL
 843             }
 844         },
 845         { &hf_wtp_header_flag_RID,
 846             {   "Re-transmission Indicator",
 847                 "wtp.RID",
 848                 FT_BOOLEAN, 8, TFS( &RID_truth ), 0x01,
 849                 "Re-transmission Indicator", HFILL
 850             }
 851         },
 852         { &hf_wtp_header_flag_TID_response,
 853             {   "TID Response",
 854                 "wtp.TID.response",
 855                 FT_BOOLEAN, 16, TFS( &tid_response_truth ), 0x8000,
 856                 "TID Response", HFILL
 857             }
 858         },
 859         { &hf_wtp_header_flag_TID,
 860             {   "Transaction ID",
 861                 "wtp.TID",
 862                 FT_UINT16, BASE_HEX, NULL, 0x7FFF,
 863                 "Transaction ID", HFILL
 864             }
 865         },
 866         { &hf_wtp_header_Inv_version,
 867             {   "Version",
 868                 "wtp.header.version",
 869                 FT_UINT8, BASE_HEX, VALS( vals_version ), 0xC0,
 870                 "Version", HFILL
 871             }
 872         },
 873         { &hf_wtp_header_Inv_flag_TIDNew,
 874             {   "TIDNew",
 875                 "wtp.header.TIDNew",
 876                 FT_BOOLEAN, 8, TFS( &TIDNew_truth ), 0x20,
 877                 "TIDNew", HFILL
 878             }
 879         },
 880         { &hf_wtp_header_Inv_flag_UP,
 881             {   "U/P flag",
 882                 "wtp.header.UP",
 883                 FT_BOOLEAN, 8, TFS( &UP_truth ), 0x10,
 884                 "U/P Flag", HFILL
 885             }
 886         },
 887         { &hf_wtp_header_Inv_Reserved,
 888             {   "Reserved",
 889                 "wtp.inv.reserved",
 890                 FT_UINT8, BASE_HEX, NULL, 0x0C,
 891                 "Reserved", HFILL
 892             }
 893         },
 894         { &hf_wtp_header_Inv_TransactionClass,
 895             {   "Transaction Class",
 896                 "wtp.inv.transaction_class",
 897                 FT_UINT8, BASE_HEX, VALS( vals_transaction_classes ), 0x03,
 898                 "Transaction Class", HFILL
 899             }
 900         },
 901         { &hf_wtp_header_Ack_flag_TVETOK,
 902             {   "Tve/Tok flag",
 903                 "wtp.ack.tvetok",
 904                 FT_BOOLEAN, 8, TFS( &TVETOK_truth ), 0x04,
 905                 "Tve/Tok flag", HFILL
 906             }
 907         },
 908         { &hf_wtp_header_Abort_type,
 909             {   "Abort Type",
 910                 "wtp.abort.type",
 911                 FT_UINT8, BASE_HEX, VALS ( vals_abort_type ), 0x07,
 912                 "Abort Type", HFILL
 913             }
 914         },
 915         { &hf_wtp_header_Abort_reason_provider,
 916             {   "Abort Reason",
 917                 "wtp.abort.reason.provider",
 918                 FT_UINT8, BASE_HEX, VALS ( vals_abort_reason_provider ), 0x00,
 919                 "Abort Reason", HFILL
 920             }
 921         },
 922         /* Assume WSP is the user and use its reason codes */
 923         { &hf_wtp_header_Abort_reason_user,
 924             {   "Abort Reason",
 925                 "wtp.abort.reason.user",
 926                 FT_UINT8, BASE_HEX, VALS ( vals_wsp_reason_codes ), 0x00,
 927                 "Abort Reason", HFILL
 928             }
 929         },
 930         { &hf_wtp_header_sequence_number,
 931             {   "Packet Sequence Number",
 932                 "wtp.header.sequence",
 933                 FT_UINT8, BASE_DEC, NULL, 0x00,
 934                 "Packet Sequence Number", HFILL
 935             }
 936         },
 937         { &hf_wtp_header_missing_packets,
 938             {   "Missing Packets",
 939                 "wtp.header.missing_packets",
 940                 FT_UINT8, BASE_DEC, NULL, 0x00,
 941                 "Missing Packets", HFILL
 942             }
 943         },
 944         { &hf_wtp_header_variable_part,
 945             {   "Header: Variable part",
 946                 "wtp.header_variable_part",
 947                 FT_BYTES, BASE_HEX, NULL, 0x0,
 948                 "Variable part of the header", HFILL
 949             }
 950         },
 951         { &hf_wtp_data,
 952             {   "Data",
 953                 "wtp.header_data",
 954                 FT_BYTES, BASE_HEX, NULL, 0x0,
 955                 "Data", HFILL
 956             }
 957         },
 958         { &hf_wtp_tpi_type,
 959             {   "TPI",
 960                 "wtp.tpi",
 961                 FT_UINT8, BASE_HEX, VALS(vals_tpi_type), 0x00,
 962                 "Identification of the Transport Information Item", HFILL
 963             }
 964         },
 965         { &hf_wtp_tpi_psn,
 966             {   "Packet sequence number",
 967                 "wtp.tpi.psn",
 968                 FT_UINT8, BASE_DEC, NULL, 0x00,
 969                 "Sequence number of this packet", HFILL
 970             }
 971         },
 972         { &hf_wtp_tpi_opt,
 973             {   "Option",
 974                 "wtp.tpi.opt",
 975                 FT_UINT8, BASE_HEX, VALS(vals_tpi_opt), 0x00,
 976                 "The given option for this TPI", HFILL
 977             }
 978         },
 979         { &hf_wtp_tpi_optval,
 980             {   "Option Value",
 981                 "wtp.tpi.opt.val",
 982                 FT_NONE, BASE_NONE, NULL, 0x00,
 983                 "The value that is supplied with this option", HFILL
 984             }
 985         },
 986         { &hf_wtp_tpi_info,
 987             {   "Information",
 988                 "wtp.tpi.info",
 989                 FT_NONE, BASE_NONE, NULL, 0x00,
 990                 "The information being send by this TPI", HFILL
 991             }
 992         },
 993
 994         /* Fragment fields */
 995         { &hf_wtp_fragment_overlap,
 996             {   "Fragment overlap",
 997                 "wtp.fragment.overlap",
 998                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 999                 "Fragment overlaps with other fragments", HFILL
1000             }
1001         },
1002         { &hf_wtp_fragment_overlap_conflict,
1003             {   "Conflicting data in fragment overlap",
1004                 "wtp.fragment.overlap.conflict",
1005                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
1006                 "Overlapping fragments contained conflicting data", HFILL
1007             }
1008         },
1009         { &hf_wtp_fragment_multiple_tails,
1010             {   "Multiple tail fragments found",
1011                 "wtp.fragment.multipletails",
1012                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
1013                 "Several tails were found when defragmenting the packet", HFILL
1014             }
1015         },
1016         { &hf_wtp_fragment_too_long_fragment,
1017             {   "Fragment too long",
1018                 "wtp.fragment.toolongfragment",
1019                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
1020                 "Fragment contained data past end of packet", HFILL
1021             }
1022         },
1023         { &hf_wtp_fragment_error,
1024             {   "Defragmentation error",
1025                 "wtp.fragment.error",
1026                 FT_FRAMENUM, BASE_NONE, NULL, 0x0,
1027                 "Defragmentation error due to illegal fragments", HFILL
1028             }
1029         },
1030         { &hf_wtp_reassembled_in,
1031             {   "Reassembled in",
1032                 "wtp.reassembled.in",
1033                 FT_FRAMENUM, BASE_NONE, NULL, 0x0,
1034                 "WTP fragments are reassembled in the given packet", HFILL
1035             }
1036         },
1037         { &hf_wtp_fragment,
1038             {   "WTP Fragment",
1039                 "wtp.fragment",
1040                 FT_FRAMENUM, BASE_NONE, NULL, 0x0,
1041                 "WTP Fragment", HFILL
1042             }
1043         },
1044         { &hf_wtp_fragments,
1045             {   "WTP Fragments",
1046                 "wtp.fragments",
1047                 FT_NONE, BASE_NONE, NULL, 0x0,
1048                 "WTP Fragments", HFILL
1049             }
1050         },
1051     };
1052
1053     /* Setup protocol subtree array */
1054     static gint *ett[] = {
1055         &ett_wtp,
1056         &ett_wtp_sub_pdu_tree,
1057         &ett_header,
1058         &ett_tpilist,
1059         &ett_wsp_fragments,
1060         &ett_wtp_fragment,
1061     };
1062
1063     /* Register the protocol name and description */
1064     proto_wtp = proto_register_protocol(
1065         "Wireless Transaction Protocol",   /* protocol name for use by ethereal */
1066         "WTP",                             /* short version of name */
1067         "wtp"                      /* Abbreviated protocol name, should Match IANA
1068                                             < URL:http://www.iana.org/assignments/port-numbers/ >
1069                                             */
1070     );
1071
1072     /* Required calls to register the header fields and subtrees used */
1073     proto_register_field_array(proto_wtp, hf, array_length(hf));
1074     proto_register_subtree_array(ett, array_length(ett));
1075
1076     register_dissector("wtp-wtls", dissect_wtp_fromwtls, proto_wtp);
1077     register_dissector("wtp-udp", dissect_wtp_fromudp, proto_wtp);
1078     register_init_routine(wtp_defragment_init);
1079 }
1080
1081 void
1082 proto_reg_handoff_wtp(void)
1083 {
1084     dissector_handle_t wtp_fromudp_handle;
1085
1086     /*
1087      * Get a handle for the connection-oriented WSP dissector - if WTP
1088      * PDUs have data, it is WSP.
1089      */
1090     wsp_handle = find_dissector("wsp-co");
1091
1092     wtp_fromudp_handle = find_dissector("wtp-udp");
1093     dissector_add("udp.port", UDP_PORT_WTP_WSP, wtp_fromudp_handle);
1094     dissector_add("gsm-sms-ud.udh.port", UDP_PORT_WTP_WSP, wtp_fromudp_handle);
1095 }