epan/dissectors/packet-nwmtp.c

   1 /* packet-nwmtp.c
   2  * Routines for NexusWare MTP3 over UDP transport
   3  * Copyright 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
   4  * Copyright 2010 by On-Waves
   5  *
   6  * $Id$
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 #include "config.h"
  28
  29 #include <glib.h>
  30
  31 #include <epan/packet.h>
  32
  33
  34 static dissector_handle_t mtp_handle;
  35 static gint proto_nwmtp = -1;
  36
  37 static int hf_nwmtp_transp_type = -1;
  38 static int hf_nwmtp_user_context = -1;
  39 static int hf_nwmtp_data_type = -1;
  40 static int hf_nwmtp_data_index = -1;
  41 static int hf_nwmtp_data_length = -1;
  42
  43 /* subtree pointer */
  44 static gint ett_mwmtp = -1;
  45
  46 static dissector_handle_t nwmtp_handle;
  47
  48 static const value_string nwmtp_transport_type_vals[] = {
  49         { 2,        "UDP" },
  50         { 3,        "TCP" },
  51         { 0,        NULL  },
  52 };
  53
  54 static const value_string nwmtp_data_type_vals[] = {
  55         { 0,        "MSU Prio 0" },
  56         { 1,        "MSU Prio 1" },
  57         { 2,        "MSU Prio 2" },
  58         { 3,        "MSU Prio 3" },
  59         {16,        "Retrieved MSU Prio 0" },
  60         {17,        "Retrieved MSU Prio 0" },
  61         {18,        "Retrieved MSU Prio 0" },
  62         {32,        "Retrieval complete"   },
  63         {33,        "Retrieval impossible" },
  64         {34,        "Link in service"      },
  65         {35,        "Link out of service"  },
  66         { 0,        NULL },
  67 };
  68
  69 static void dissect_nwmtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  70 {
  71         gint offset = 0;
  72
  73         col_set_str(pinfo->cinfo, COL_PROTOCOL, "NW MTP");
  74         col_clear(pinfo->cinfo, COL_INFO);
  75
  76         while (tvb_reported_length_remaining(tvb, offset) > 0) {
  77                 const gchar *type;
  78                 proto_item *ti;
  79                 proto_item *nwmtp_tree;
  80                 guint32 len;
  81                 tvbuff_t *next_tvb;
  82
  83                 /* update the info column */
  84                 type = val_to_str_const(tvb_get_guint8(tvb, offset + 1),
  85                                         nwmtp_data_type_vals, "Unknown");
  86                 col_set_str(pinfo->cinfo, COL_INFO, type);
  87
  88                 len = tvb_get_ntohl(tvb, offset + 8);
  89
  90                 if (tree) {
  91                         ti = proto_tree_add_protocol_format(tree, proto_nwmtp,
  92                                         tvb, offset, len + 12,
  93                                         "NexusWare C7 UDP Protocol");
  94
  95                         nwmtp_tree = proto_item_add_subtree(ti, ett_mwmtp);
  96                         proto_tree_add_item(nwmtp_tree, hf_nwmtp_transp_type,
  97                                             tvb, offset, 1, ENC_BIG_ENDIAN);
  98                         proto_tree_add_item(nwmtp_tree, hf_nwmtp_data_type,
  99                                             tvb, offset + 1, 1, ENC_BIG_ENDIAN);
 100                         proto_tree_add_item(nwmtp_tree, hf_nwmtp_data_index,
 101                                             tvb, offset + 2, 2, ENC_BIG_ENDIAN);
 102                         proto_tree_add_item(nwmtp_tree, hf_nwmtp_user_context,
 103                                             tvb, offset + 4, 4, ENC_BIG_ENDIAN);
 104                         proto_tree_add_item(nwmtp_tree, hf_nwmtp_data_length,
 105                                             tvb, offset + 8, 4, ENC_BIG_ENDIAN);
 106                 }
 107
 108                 next_tvb = tvb_new_subset(tvb, offset + 12, len, len);
 109                 if (tvb_length(next_tvb) > 0)
 110                         call_dissector(mtp_handle, next_tvb, pinfo, tree);
 111                 /* Check for overflows, which probably can't happen, but better
 112                  * safe than sorry. See
 113                  * https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8169
 114                  */
 115                 DISSECTOR_ASSERT(len < G_MAXUINT32 - 11);
 116                 DISSECTOR_ASSERT((guint64)offset + len + 12 < G_MAXINT);
 117                 offset += len + 12;
 118         }
 119 }
 120
 121 void proto_register_mwmtp(void)
 122 {
 123         static hf_register_info hf[] = {
 124                 {&hf_nwmtp_transp_type,
 125                  {"Transport Type", "nwmtp.transp_type",
 126                   FT_UINT8, BASE_DEC, VALS(nwmtp_transport_type_vals), 0x0,
 127                   "The Transport Type", HFILL}
 128                 },
 129                 {&hf_nwmtp_data_type,
 130                  {"Data Type", "nwmtp.data_type",
 131                   FT_UINT8, BASE_DEC, VALS(nwmtp_data_type_vals), 0x0,
 132                   "The Data Type", HFILL}
 133                 },
 134                 {&hf_nwmtp_data_index,
 135                  {"Link Index", "nwmtp.link_index",
 136                   FT_UINT16, BASE_DEC, NULL, 0x0,
 137                   NULL, HFILL}
 138                 },
 139                 {&hf_nwmtp_user_context,
 140                  {"User Context", "nwmtp.user_context",
 141                   FT_UINT32, BASE_DEC, NULL, 0x0,
 142                   "Use Context", HFILL}
 143                 },
 144                 {&hf_nwmtp_data_length,
 145                  {"Length", "nwmtp.data_length",
 146                   FT_UINT32, BASE_DEC, NULL, 0x0,
 147                   "Data Length", HFILL}
 148                 },
 149         };
 150
 151         static gint *ett[] = {
 152                 &ett_mwmtp,
 153         };
 154
 155         proto_nwmtp =
 156              proto_register_protocol("NexusWare C7 MTP", "MTP over NW UDP", "nw_mtp");
 157
 158         proto_register_field_array(proto_nwmtp, hf, array_length(hf));
 159         proto_register_subtree_array(ett, array_length(ett));
 160
 161         nwmtp_handle = register_dissector("nw_mtp", dissect_nwmtp, proto_nwmtp);
 162 }
 163
 164 void proto_reg_handoff_nwmtp(void)
 165 {
 166         /* For decode as */
 167         dissector_add_handle("udp.port", nwmtp_handle);
 168         mtp_handle = find_dissector("mtp3");
 169 }
 170
 171 /*
 172  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 173  *
 174  * Local variables:
 175  * c-basic-offset: 8
 176  * tab-width: 8
 177  * indent-tabs-mode: t
 178  * End:
 179  *
 180  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 181  * :indentSize=8:tabSize=8:noTabs=false:
 182  */