plugins/interlink/packet-interlink.c

   1 /* packet-interlink.c
   2  * Routines for Interlink protocol packet disassembly
   3  * By Uwe Girlich <uwe.girlich@philosys.de>
   4  * Copyright 2010 Uwe Girlich
   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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <epan/packet.h>
  32
  33
  34 /*
  35  * No public information available.
  36  */
  37
  38 static int proto_interlink = -1;
  39
  40 static int hf_interlink_id = -1;
  41 static int hf_interlink_version = -1;
  42 static int hf_interlink_cmd = -1;
  43 static int hf_interlink_seq = -1;
  44 static int hf_interlink_flags = -1;
  45 static int hf_interlink_flags_req_ack = -1;
  46 static int hf_interlink_flags_inc_ack_port = -1;
  47 static int hf_interlink_block_type = -1;
  48 static int hf_interlink_block_version = -1;
  49 static int hf_interlink_block_length = -1;
  50
  51 static gint ett_interlink = -1;
  52 static gint ett_interlink_header = -1;
  53 static gint ett_interlink_flags = -1;
  54 static gint ett_interlink_block = -1;
  55
  56 static dissector_handle_t data_handle;
  57 static dissector_table_t subdissector_table;
  58
  59 static const true_false_string flags_set_notset = {
  60         "Set", "Not set"
  61 };
  62
  63 static const value_string names_cmd[] = {
  64         { 1, "Data" },
  65         { 2, "Ack" },
  66         { 0, NULL }
  67 };
  68
  69
  70 static void
  71 dissect_interlink(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  72 {
  73         int             offset = 0;
  74         proto_tree      *il_tree = NULL;
  75         proto_tree      *ilh_tree = NULL;
  76         proto_tree      *ilb_tree = NULL;
  77         guint8          ilb_type;
  78         guint8          ilb_version;
  79         guint16         type_version = 0;
  80         dissector_handle_t      handle;
  81         tvbuff_t        *next_tvb;
  82
  83         col_set_str(pinfo->cinfo, COL_PROTOCOL, "INTERLINK");
  84         col_clear(pinfo->cinfo, COL_INFO);
  85
  86         if (tree) {
  87                 proto_item      *il_item;
  88                 il_item = proto_tree_add_item(tree, proto_interlink,
  89                                                                 tvb, 0, 16, FALSE);
  90                 if (il_item)
  91                         il_tree = proto_item_add_subtree(il_item, ett_interlink);
  92         }
  93
  94         if (il_tree) {
  95                 proto_item      *ilh_item = NULL;
  96                 ilh_item = proto_tree_add_text(il_tree, tvb, 0, 12, "Interlink Header");
  97                 if (ilh_item)
  98                         ilh_tree = proto_item_add_subtree(ilh_item, ett_interlink_header);
  99         }
 100
 101         if (ilh_tree) {
 102                 proto_tree_add_item(ilh_tree, hf_interlink_id, tvb, offset, 4, FALSE);
 103                 offset += 4;
 104                 proto_tree_add_item(ilh_tree, hf_interlink_version, tvb, offset, 2, TRUE);
 105                 offset += 2;
 106                 proto_tree_add_item(ilh_tree, hf_interlink_cmd, tvb, offset, 2, TRUE);
 107                 offset += 2;
 108                 proto_tree_add_item(ilh_tree, hf_interlink_seq, tvb, offset, 2, TRUE);
 109                 offset += 2;
 110         }
 111
 112         if (ilh_tree) {
 113                 proto_item      *flags_item;
 114                 proto_tree      *flags_tree = NULL;
 115
 116                 flags_item = proto_tree_add_item(ilh_tree, hf_interlink_flags,
 117                         tvb, offset, 2, TRUE);
 118                 if (flags_item) {
 119                         flags_tree = proto_item_add_subtree(flags_item, ett_interlink_flags);
 120                 }
 121                 if (flags_tree) {
 122                         guint16         il_flags;
 123                         il_flags = tvb_get_letohs(tvb, offset);
 124                         proto_tree_add_boolean(flags_tree, hf_interlink_flags_req_ack, tvb, offset, 2, il_flags);
 125                         proto_tree_add_boolean(flags_tree, hf_interlink_flags_inc_ack_port, tvb, offset, 2, il_flags);
 126                 }
 127         }
 128         offset += 2;
 129
 130         if (tree) {
 131                 proto_item      *ilb_item;
 132                 ilb_item = proto_tree_add_text(il_tree, tvb, offset, 4, "Block Header");
 133                 if (ilb_item)
 134                         ilb_tree = proto_item_add_subtree(ilb_item, ett_interlink_block);
 135         }
 136
 137         ilb_type = tvb_get_guint8(tvb, offset);
 138         ilb_version = tvb_get_guint8(tvb, offset + 1);
 139         type_version = ilb_type << 8 | ilb_version;
 140         col_append_fstr(pinfo->cinfo, COL_INFO, "Type: 0x%02x, Version: %d",
 141                 ilb_type, ilb_version);
 142
 143         if (ilb_tree) {
 144                 proto_tree_add_item(ilb_tree, hf_interlink_block_type, tvb, offset, 1, FALSE);
 145                 offset += 1;
 146                 proto_tree_add_item(ilb_tree, hf_interlink_block_version, tvb, offset, 1, FALSE);
 147                 offset += 1;
 148                 proto_tree_add_item(ilb_tree, hf_interlink_block_length, tvb, offset, 2, TRUE);
 149                 offset += 2;
 150         }
 151
 152         /* Generate a new tvb for the rest. */
 153         next_tvb = tvb_new_subset_remaining(tvb, offset);
 154
 155         /* Probably a sub-dissector exists for this type/version combination. */
 156         handle = dissector_get_port_handle(subdissector_table, type_version);
 157
 158         /* Without a proper sub-dissector, we use "data". */
 159         if (handle == NULL) handle = data_handle;
 160
 161         /* Call the sub-dissector. */
 162         call_dissector(handle, next_tvb, pinfo, tree);
 163 }
 164
 165
 166 static gboolean
 167 dissect_interlink_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 168 {
 169         if (!tvb_bytes_exist(tvb, 0, 4)) {
 170                 return FALSE;
 171         }
 172         if (
 173                 tvb_get_guint8(tvb,0) != 'I' ||
 174                 tvb_get_guint8(tvb,1) != 'L' ||
 175                 tvb_get_guint8(tvb,2) != 'N' ||
 176                 tvb_get_guint8(tvb,3) != 'K'
 177         )
 178                 return FALSE;
 179
 180         dissect_interlink(tvb, pinfo, tree);
 181         return TRUE;
 182 }
 183
 184
 185 void
 186 proto_register_interlink(void)
 187 {
 188         static hf_register_info hf[] = {
 189                 { &hf_interlink_id, {
 190                         "Magic ID", "interlink.id", FT_STRING,
 191                         BASE_NONE, NULL, 0, NULL, HFILL }},
 192                 { &hf_interlink_version, {
 193                         "Version", "interlink.version", FT_UINT16,
 194                         BASE_DEC, NULL, 0, NULL, HFILL }},
 195                 { &hf_interlink_cmd, {
 196                         "Command", "interlink.cmd", FT_UINT16,
 197                         BASE_DEC, VALS(names_cmd), 0, NULL, HFILL }},
 198                 { &hf_interlink_seq, {
 199                         "Sequence", "interlink.seq", FT_UINT16,
 200                         BASE_DEC, NULL, 0, NULL, HFILL }},
 201                 { &hf_interlink_flags, {
 202                         "Flags", "interlink.flags", FT_UINT16,
 203                         BASE_HEX, NULL, 0, NULL, HFILL }},
 204                 { &hf_interlink_flags_req_ack, {
 205                         "REQ_ACK", "interlink.flags.req_ack", FT_BOOLEAN,
 206                         16, TFS(&flags_set_notset), 0x01, NULL, HFILL }},
 207                 { &hf_interlink_flags_inc_ack_port, {
 208                         "INC_ACK_PORT", "interlink.flags.inc_ack_port", FT_BOOLEAN,
 209                         16, TFS(&flags_set_notset), 0x02, NULL, HFILL }},
 210                 { &hf_interlink_block_type, {
 211                         "Type", "interlink.type", FT_UINT8,
 212                         BASE_HEX, NULL, 0, NULL, HFILL }},
 213                 { &hf_interlink_block_version, {
 214                         "Version", "interlink.block_version", FT_UINT8,
 215                         BASE_DEC, NULL, 0, NULL, HFILL }},
 216                 { &hf_interlink_block_length, {
 217                         "Length", "interlink.length", FT_UINT16,
 218                         BASE_DEC, NULL, 0, NULL, HFILL }},
 219         };
 220
 221         static gint *ett[] = {
 222                 &ett_interlink,
 223                 &ett_interlink_header,
 224                 &ett_interlink_flags,
 225                 &ett_interlink_block,
 226         };
 227
 228         proto_interlink = proto_register_protocol("Interlink Protocol",
 229                                                         "Interlink",
 230                                                         "interlink");
 231         proto_register_field_array(proto_interlink, hf, array_length(hf));
 232         proto_register_subtree_array(ett, array_length(ett));
 233         register_dissector("interlink", dissect_interlink, proto_interlink);
 234
 235         /* Probably someone will write sub-dissectors. You can never know. */
 236         subdissector_table = register_dissector_table("interlink.type_version",
 237                 "Interlink type_version", FT_UINT16, BASE_HEX);
 238 }
 239
 240
 241 void
 242 proto_reg_handoff_interlink(void)
 243 {
 244         dissector_handle_t interlink_handle;
 245         interlink_handle = find_dissector("interlink");
 246
 247         /* Allow "Decode As" with any UDP packet. */
 248         dissector_add_handle("udp.port", interlink_handle);
 249
 250         /* Add our heuristic packet finder. */
 251         heur_dissector_add("udp", dissect_interlink_heur, proto_interlink);
 252
 253         data_handle = find_dissector("data");
 254 }
 255