epan/dissectors/packet-tali.c

   1 /* packet-tali.c
   2  *
   3  * Routines for Transport Adapter Layer Interface (TALI) version 1.0 dissection (RFC 3094)
   4  *
   5  * Copyright : 2004 Viorel Suman, <vsuman[AT]avmob.ro>
   6  *             In association with Avalanche Mobile BV, http://www.avmob.com
   7  *
   8  * Dissector of a TALI (Transport Adapter Layer Interface) version 1.0, as defined by the
   9  * Tekelec (www.tekelec.com) in RFC 3094, http://www.ietf.org/rfc/rfc3094.txt
  10  *
  11  * $Id$
  12  *
  13  * Refer to the AUTHORS file or the AUTHORS section in the man page
  14  * for contacting the author(s) of this file.
  15  *
  16  * Wireshark - Network traffic analyzer
  17  * By Gerald Combs <gerald@wireshark.org>
  18  * Copyright 1998 Gerald Combs
  19  *
  20  * This program is free software; you can redistribute it and/or
  21  * modify it under the terms of the GNU General Public License
  22  * as published by the Free Software Foundation; either version 2
  23  * of the License, or (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program; if not, write to the Free Software
  32  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  33  */
  34
  35 #define NEW_PROTO_TREE_API
  36
  37 #include "config.h"
  38
  39 #include <string.h>
  40 #include <glib.h>
  41
  42 #include <epan/packet.h>
  43 #include <epan/prefs.h>
  44 #include "packet-tcp.h"
  45
  46 #define TALI_SYNC_LENGTH    4
  47 #define TALI_OPCODE_LENGTH  4
  48 #define TALI_MSU_LENGTH     2
  49 #define TALI_HEADER_LENGTH  TALI_SYNC_LENGTH + TALI_OPCODE_LENGTH + TALI_MSU_LENGTH
  50
  51 #define TALI_SYNC "TALI"
  52 #define TALI_TEST "test"
  53 #define TALI_ALLO "allo"
  54 #define TALI_PROH "proh"
  55 #define TALI_PROA "proa"
  56 #define TALI_MONI "moni"
  57 #define TALI_MONA "mona"
  58 #define TALI_SCCP "sccp"
  59 #define TALI_ISOT "isot"
  60 #define TALI_MTP3 "mtp3"
  61 #define TALI_SAAL "saal"
  62
  63 /* Initialize the subtree pointers */
  64 static gint ett_tali = -1;
  65 static gint ett_tali_sync = -1;
  66 static gint ett_tali_opcode = -1;
  67 static gint ett_tali_msu_length = -1;
  68
  69 static header_field_info *hfi_tali = NULL;
  70
  71 #define TALI_HFI_INIT HFI_INIT(proto_tali)
  72
  73 /* Initialize the protocol and registered fields */
  74 static header_field_info hfi_tali_sync_indicator TALI_HFI_INIT =
  75       { "Sync", "tali.sync", FT_STRING, BASE_NONE, NULL, 0x00, "TALI SYNC", HFILL };
  76
  77 static header_field_info hfi_tali_opcode_indicator TALI_HFI_INIT =
  78       { "Opcode", "tali.opcode", FT_STRING, BASE_NONE, NULL, 0x00, "TALI Operation Code", HFILL };
  79
  80 static header_field_info hfi_tali_length_indicator TALI_HFI_INIT =
  81       { "Length", "tali.msu_length", FT_UINT16, BASE_DEC, NULL, 0x00, "TALI MSU Length", HFILL };
  82
  83 static dissector_table_t tali_dissector_table;
  84
  85 static dissector_handle_t data_handle;
  86
  87 /* Desegment TALI messages */
  88 static gboolean tali_desegment = TRUE;
  89
  90 /* Code to actually dissect the packets */
  91 static guint
  92 get_tali_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
  93 {
  94   guint16 length;
  95
  96   length = tvb_get_letohs(tvb, offset + TALI_SYNC_LENGTH + TALI_OPCODE_LENGTH);
  97   return length+TALI_HEADER_LENGTH;
  98 }
  99
 100 static int
 101 dissect_tali_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 102 {
 103   char opcode[TALI_OPCODE_LENGTH+1]; /* TALI opcode */
 104   guint16 length; /* TALI length */
 105   tvbuff_t *payload_tvb = NULL;
 106
 107   /* Set up structures needed to add the protocol subtree and manage it */
 108   proto_item *tali_item = NULL;
 109   proto_tree *tali_tree = NULL;
 110
 111   tvb_memcpy(tvb, (guint8*)opcode, TALI_SYNC_LENGTH, TALI_OPCODE_LENGTH);
 112   opcode[TALI_OPCODE_LENGTH] = '\0';
 113   length = tvb_get_letohs(tvb, TALI_SYNC_LENGTH + TALI_OPCODE_LENGTH);
 114
 115   /* Make entries in Protocol column on summary display */
 116   col_set_str(pinfo->cinfo, COL_PROTOCOL, "TALI");
 117
 118   col_set_str(pinfo->cinfo, COL_INFO, "");
 119   col_append_fstr(pinfo->cinfo, COL_INFO, "[%s] packet, [%u] bytes in payload", opcode, length);
 120
 121   if (tree) {
 122     /* create display subtree for the protocol */
 123     tali_item = proto_tree_add_item(tree, hfi_tali, tvb, 0, TALI_HEADER_LENGTH, ENC_NA);
 124     tali_tree = proto_item_add_subtree(tali_item, ett_tali);
 125     proto_tree_add_string(tali_tree, &hfi_tali_sync_indicator,   tvb, 0, TALI_SYNC_LENGTH, TALI_SYNC);
 126     proto_tree_add_string(tali_tree, &hfi_tali_opcode_indicator, tvb, TALI_SYNC_LENGTH, TALI_OPCODE_LENGTH, opcode);
 127     proto_tree_add_uint(tali_tree, &hfi_tali_length_indicator, tvb, TALI_SYNC_LENGTH + TALI_OPCODE_LENGTH, TALI_MSU_LENGTH, length);
 128   }
 129
 130   if (length > 0) {
 131     payload_tvb = tvb_new_subset_remaining(tvb, TALI_HEADER_LENGTH);
 132     if (payload_tvb != NULL && !dissector_try_string(tali_dissector_table, opcode, payload_tvb, pinfo, tree, NULL)) {
 133       call_dissector(data_handle, payload_tvb, pinfo, tree);
 134     }
 135   }
 136
 137   return tvb_length(tvb);
 138 }
 139
 140 static int
 141 dissect_tali(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
 142 {
 143   tcp_dissect_pdus(tvb, pinfo, tree, tali_desegment, TALI_HEADER_LENGTH,
 144                    get_tali_pdu_len, dissect_tali_pdu, data);
 145   return tvb_length(tvb);
 146 }
 147
 148 /*
 149  * A 'heuristic dissector' that attemtps to establish whether we have
 150  * a TALI MSU here.
 151  * Only works when:
 152  *      the fixed header is there
 153  *      it is a 'well-known' operation
 154  */
 155 static gboolean
 156 dissect_tali_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
 157 {
 158   char opcode[TALI_OPCODE_LENGTH]; /* TALI opcode */
 159
 160   if (tvb_reported_length(tvb) < TALI_HEADER_LENGTH)    /* Mandatory header     */
 161     return FALSE;
 162
 163   if (tvb_strneql(tvb, 0, TALI_SYNC, TALI_SYNC_LENGTH) != 0)
 164     return FALSE;
 165
 166   tvb_memcpy(tvb, (guint8*)opcode, TALI_SYNC_LENGTH, TALI_OPCODE_LENGTH);
 167   if (strncmp(opcode, TALI_TEST, TALI_OPCODE_LENGTH) != 0 &&
 168       strncmp(opcode, TALI_ALLO, TALI_OPCODE_LENGTH) != 0 &&
 169       strncmp(opcode, TALI_PROH, TALI_OPCODE_LENGTH) != 0 &&
 170       strncmp(opcode, TALI_PROA, TALI_OPCODE_LENGTH) != 0 &&
 171       strncmp(opcode, TALI_MONI, TALI_OPCODE_LENGTH) != 0 &&
 172       strncmp(opcode, TALI_MONA, TALI_OPCODE_LENGTH) != 0 &&
 173       strncmp(opcode, TALI_SCCP, TALI_OPCODE_LENGTH) != 0 &&
 174       strncmp(opcode, TALI_ISOT, TALI_OPCODE_LENGTH) != 0 &&
 175       strncmp(opcode, TALI_MTP3, TALI_OPCODE_LENGTH) != 0 &&
 176       strncmp(opcode, TALI_SAAL, TALI_OPCODE_LENGTH) != 0)
 177     return FALSE;
 178
 179   dissect_tali(tvb, pinfo, tree, data);
 180   return TRUE;
 181 }
 182
 183 void
 184 proto_register_tali(void)
 185 {
 186 #ifndef HAVE_HFI_SECTION_INIT
 187   static header_field_info *hfi[] = {
 188     &hfi_tali_sync_indicator,
 189     &hfi_tali_opcode_indicator,
 190     &hfi_tali_length_indicator
 191   };
 192 #endif
 193
 194   /* Setup protocol subtree array */
 195   static gint *ett[] = {
 196     &ett_tali,
 197     &ett_tali_sync,
 198     &ett_tali_opcode,
 199     &ett_tali_msu_length
 200   };
 201   module_t *tali_module;
 202
 203   int proto_tali;
 204
 205   /* Register the protocol name and description */
 206   proto_tali = proto_register_protocol("Transport Adapter Layer Interface v1.0, RFC 3094", "TALI", "tali");
 207   hfi_tali   = proto_registrar_get_nth(proto_tali);
 208
 209   new_register_dissector("tali", dissect_tali, proto_tali);
 210
 211   /* Required function calls to register the header fields and subtrees used */
 212   proto_register_fields(proto_tali, hfi, array_length(hfi));
 213   proto_register_subtree_array(ett, array_length(ett));
 214
 215   tali_dissector_table = register_dissector_table("tali.opcode", "Tali OPCODE", FT_STRING, BASE_NONE);
 216
 217   tali_module = prefs_register_protocol(proto_tali, NULL);
 218   prefs_register_bool_preference(tali_module, "reassemble",
 219         "Reassemble TALI messages spanning multiple TCP segments",
 220         "Whether the TALI dissector should reassemble messages spanning multiple TCP segments."
 221         " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
 222     &tali_desegment);
 223 }
 224
 225 void
 226 proto_reg_handoff_tali(void)
 227 {
 228   heur_dissector_add("tcp", dissect_tali_heur, hfi_tali->id);
 229
 230   data_handle = find_dissector("data");
 231 }
 232