epan/dissectors/packet-gmr1_dtap.c

   1 /* packet-gmr1_dtap.c
   2  *
   3  * Routines for GMR-1 DTAP dissection in wireshark.
   4  * Copyright (c) 2011 Sylvain Munaut <tnt@246tNt.com>
   5  *
   6  * References:
   7  *  [1] ETSI TS 101 376-4-8 V1.3.1 - GMR-1 04.008
   8  *  [2] ETSI TS 101 376-4-8 V2.2.1 - GMPRS-1 04.008
   9  *  [3] ETSI TS 101 376-4-8 V3.1.1 - GMR-1 3G 44.008
  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 #include "config.h"
  33
  34 #include <glib.h>
  35 #include <epan/packet.h>
  36
  37 #include "packet-gmr1_common.h"
  38
  39
  40 /* GMR-1 DTAP proto */
  41 static int proto_gmr1_dtap = -1;
  42
  43 /* GMR-1 DTAP sub tree */
  44 static gint ett_gmr1_dtap = -1;
  45 static gint ett_gmr1_pd = -1;
  46
  47 /* Handoffs */
  48 static dissector_handle_t gsm_dtap_handle;
  49
  50
  51 static void
  52 dissect_gmr1_dtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  53 {
  54         guint32 len, offset;
  55         gmr1_msg_func_t msg_func;
  56         const gchar *msg_str;
  57         gint ett_tree;
  58         int hf_idx;
  59         proto_item *dtap_item = NULL/*, *pd_item = NULL*/;
  60         proto_tree *dtap_tree = NULL/*, *pd_tree = NULL*/;
  61         guint32 oct[2];
  62         guint8 pd;
  63
  64         /* Scan init */
  65         len = tvb_length(tvb);
  66         offset = 0;
  67
  68         /* Protocol descriptor */
  69         oct[0] = tvb_get_guint8(tvb, offset++);
  70
  71         if ((oct[0] & GMR1_PD_EXT_MSK) == GMR1_PD_EXT_VAL)
  72                 pd = oct[0] & 0xff;
  73         else
  74                 pd = oct[0] & 0x0f;
  75
  76         /* HACK: Quick delegation hack to GSM */
  77         if (pd != GMR1_PD_RR) {
  78                 call_dissector(gsm_dtap_handle, tvb, pinfo, tree);
  79                 return;
  80         }
  81
  82         /* Fill up some info */
  83         col_append_str(pinfo->cinfo, COL_INFO, " (DTAP) ");
  84
  85         col_append_fstr(pinfo->cinfo, COL_INFO, "(%s) ",
  86                 val_to_str(pd, gmr1_pd_short_vals, "Unknown (%u)"));
  87
  88         /* Get message parameters */
  89         oct[1] = tvb_get_guint8(tvb, offset);
  90
  91         gmr1_get_msg_params((gmr1_pd_e)pd, oct[1], &msg_str, &ett_tree, &hf_idx, &msg_func);
  92
  93         /* Create protocol tree */
  94         if (msg_str == NULL)
  95         {
  96                 dtap_item = proto_tree_add_protocol_format(
  97                         tree, proto_gmr1_dtap, tvb, 0, len,
  98                         "GMR-1 DTAP - Message Type (0x%02x)", oct[1]);
  99                 dtap_tree = proto_item_add_subtree(dtap_item, ett_gmr1_dtap);
 100
 101                 col_append_fstr(pinfo->cinfo, COL_INFO, "Message Type (0x%02x) ", oct[1]);
 102         }
 103         else
 104         {
 105                 dtap_item = proto_tree_add_protocol_format(
 106                         tree, proto_gmr1_dtap, tvb, 0, -1,
 107                         "GMR-1 DTAP - %s", msg_str);
 108                 dtap_tree = proto_item_add_subtree(dtap_item, ett_gmr1_dtap);
 109
 110                 col_append_fstr(pinfo->cinfo, COL_INFO, "%s ", msg_str);
 111         }
 112
 113         /* Start over */
 114         offset = 0;
 115
 116         /* Protocol discriminator item */
 117         /*pd_item =*/ proto_tree_add_text(
 118                 dtap_tree, tvb, 1, 1,
 119                 "Protocol Discriminator: %s",
 120                 val_to_str(pd, gmr1_pd_vals, "Unknown (%u)")
 121         );
 122
 123         /*pd_tree = proto_item_add_subtree(pd_item, ett_gmr1_pd);*/
 124
 125                 /* Move on */
 126         offset++;
 127
 128         /* Message type - [1] 11.4 */
 129         proto_tree_add_uint_format(
 130                 dtap_tree, hf_idx, tvb, offset, 1, oct[1],
 131                 "Message Type: %s", msg_str ? msg_str : "(Unknown)"
 132         );
 133
 134         offset++;
 135
 136         /* Decode elements */
 137         if (msg_func) {
 138                 (*msg_func)(tvb, dtap_tree, pinfo, offset, len - offset);
 139         } else {
 140                 proto_tree_add_text(dtap_tree, tvb, offset, len - offset,
 141                                     "Message Elements");
 142         }
 143
 144         /* Done ! */
 145         return;
 146 }
 147
 148
 149 void
 150 proto_register_gmr1_dtap(void)
 151 {
 152 #if 0
 153         static hf_register_info hf[] = {
 154         };
 155 #endif
 156         static gint *ett[] = {
 157                 &ett_gmr1_dtap,
 158                 &ett_gmr1_pd,
 159         };
 160
 161         /* Setup protocol subtree array */
 162         proto_register_subtree_array(ett, array_length(ett));
 163
 164         /* Register the protocol name and field description */
 165         proto_gmr1_dtap = proto_register_protocol("GEO-Mobile Radio (1) DTAP", "GMR-1 DTAP", "gmr1.dtap");
 166 #if 0
 167         proto_register_field_array(proto_gmr1_dtap, hf, array_length(hf));
 168 #endif
 169         /* Register dissector */
 170         register_dissector("gmr1_dtap", dissect_gmr1_dtap, proto_gmr1_dtap);
 171 }
 172
 173 void
 174 proto_reg_handoff_gmr1_dtap(void)
 175 {
 176         dissector_handle_t dtap_handle;
 177
 178         dtap_handle = find_dissector("gmr1_dtap");
 179         dissector_add_uint("lapsat.sapi", 0 , dtap_handle); /* LAPSat: CC/RR/MM */
 180         dissector_add_uint("lapsat.sapi", 3 , dtap_handle); /* LAPSat: SMS/SS */
 181
 182         gsm_dtap_handle = find_dissector("gsm_a_dtap");
 183 }