epan/dissectors/packet-trdp.c

   1 /* packet-trdp.c
   2  * Routines for TRDP dissection
   3  * Copyright 2020, EKE-Electronics Ltd, Kalle Pokki <kalle.pokki@eke.fi>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 /*
  13  * The Train Real-Time Data Protocol (TRDP) is defined in IEC 61375-2-3. The
  14  * protocol is used to exchange Train Communication Network (TCN) process data
  15  * and message data.
  16  *
  17  * NOTE: Message data support incomplete.
  18  */
  19
  20 #include <config.h>
  21 #include <epan/packet.h>
  22 #include <packet-tcp.h>
  23
  24 void proto_reg_handoff_trdp(void);
  25 void proto_register_trdp(void);
  26
  27 /* Initialize the protocol and registered fields */
  28 static int proto_trdp;
  29 static int hf_trdp_seq;
  30 static int hf_trdp_ver;
  31 static int hf_trdp_msgtype;
  32 static int hf_trdp_comid;
  33 static int hf_trdp_etb_topo;
  34 static int hf_trdp_oper_topo;
  35 static int hf_trdp_len;
  36 static int hf_trdp_res;
  37 static int hf_trdp_reply_comid;
  38 static int hf_trdp_reply_ipaddr;
  39 static int hf_trdp_header_fcs;
  40 static int hf_trdp_padding;
  41 static int hf_trdp_reply_status;
  42 static int hf_trdp_session_id;
  43 static int hf_trdp_reply_timeout;
  44 static int hf_trdp_source_uri;
  45 static int hf_trdp_dest_uri;
  46
  47 #define TRDP_PD_UDP_PORT 17224
  48 #define TRDP_MD_TCP_UDP_PORT 17225
  49 #define TRDP_PD_HEADER_LEN 40
  50 #define TRDP_MD_HEADER_LEN 116
  51
  52 /* Initialize the subtree pointers */
  53 static int ett_trdp;
  54
  55 /* Initialize dissector table */
  56 static dissector_table_t trdp_dissector_table;
  57 static dissector_handle_t data_handle;
  58
  59 /* Message type names */
  60 static const value_string msgtype_names[] = {
  61     { 0x4d63, "Message Data Confirm" },
  62     { 0x4d65, "Message Data Error" },
  63     { 0x4d6e, "Message Data Notification (request without reply)" },
  64     { 0x4d70, "Message Data Reply without Confirmation" },
  65     { 0x4d71, "Message Data Reply with Confirmation" },
  66     { 0x4d72, "Message Data Request" },
  67     { 0x5064, "Process Data" },
  68     { 0x5065, "Process Data Error" },
  69     { 0x5070, "Process Data Reply" },
  70     { 0x5072, "Process Data Request" },
  71     { 0, NULL }
  72 };
  73 static const value_string msgtype_names_short[] = {
  74     { 0x4d63, "Mc" },
  75     { 0x4d65, "Me" },
  76     { 0x4d6e, "Mn" },
  77     { 0x4d70, "Mp" },
  78     { 0x4d71, "Mq" },
  79     { 0x4d72, "Mr" },
  80     { 0x5064, "Pd" },
  81     { 0x5065, "Pe" },
  82     { 0x5070, "Pp" },
  83     { 0x5072, "Pr" },
  84     { 0, NULL }
  85 };
  86
  87
  88 /* Communication identifier names */
  89 static const value_string comid_names[] = {
  90     { 100, "Operational train directory status" },
  91     { 101, "Operational train directory notification" },
  92     { 106, "Train network directory information request" },
  93     { 107, "Train network directory information reply" },
  94     { 108, "Operational train directory information request" },
  95     { 109, "Operational train directory information reply" },
  96     { 120, "ECSP control telegram" },
  97     { 121, "ECSP status telegram" },
  98     { 132, "ETBN - Train network directory request" },
  99     { 133, "ETBN - Train network directory reply" },
 100     { 2204160, "EKE Modular I/O state" },
 101     { 2204161, "EKE Modular I/O control" },
 102     { 0, NULL }
 103 };
 104
 105 /* Reply status indication names
 106  * Signed int: <0: NOK; 0: OK; >0: user reply status */
 107 static const value_string reply_status_names[] = {
 108     { -1, "Reserved" },
 109     { -2, "Session abort" },
 110     { -3, "No replier instance (at replier side)" },
 111     { -4, "No memory (at replier side)" },
 112     { -5, "No memory (local)" },
 113     { -6, "No reply" },
 114     { -7, "Not all replies" },
 115     { -8, "No confirm" },
 116     { -9, "Reserved" },
 117     { -10, "Sending failed" },
 118     { 0, "Ok" },
 119     { 0, NULL }
 120 };
 121
 122 static inline int is_pd(uint16_t msgtype)
 123 {
 124     return (msgtype & 0xff00) == 0x5000; // 'P'
 125 }
 126
 127 static int dissect_trdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
 128 {
 129     proto_item *ti;
 130     proto_tree *trdp_tree;
 131     uint16_t ver;
 132     uint32_t remaining, datalen, seq, comid, etb_topo, opr_topo, msgtype, header_len;
 133     tvbuff_t *next_tvb;
 134
 135     if (tvb_reported_length(tvb) < TRDP_PD_HEADER_LEN)
 136         return 0;
 137
 138     col_set_str(pinfo->cinfo, COL_PROTOCOL, "TRDP");
 139     col_clear(pinfo->cinfo, COL_INFO);
 140
 141     header_len = is_pd(tvb_get_uint16(tvb, 6, ENC_BIG_ENDIAN)) ? TRDP_PD_HEADER_LEN : TRDP_MD_HEADER_LEN;
 142
 143     /* Create display subtree for the protocol */
 144     ti = proto_tree_add_item(tree, proto_trdp, tvb, 0, header_len, ENC_NA);
 145     trdp_tree = proto_item_add_subtree(ti, ett_trdp);
 146
 147     /* Add items to the subtree */
 148     proto_tree_add_item_ret_uint(trdp_tree, hf_trdp_seq, tvb, 0, 4, ENC_BIG_ENDIAN, &seq);
 149     ver = tvb_get_uint16(tvb, 4, ENC_BIG_ENDIAN);
 150     proto_tree_add_uint_format_value(trdp_tree, hf_trdp_ver, tvb, 4, 2, 0, "%d.%d", ver >> 8, ver & 0xff);
 151     proto_tree_add_item_ret_uint(trdp_tree, hf_trdp_msgtype, tvb, 6, 2, ENC_BIG_ENDIAN, &msgtype);
 152     proto_tree_add_item_ret_uint(trdp_tree, hf_trdp_comid, tvb, 8, 4, ENC_BIG_ENDIAN, &comid);
 153     proto_tree_add_item_ret_uint(trdp_tree, hf_trdp_etb_topo, tvb, 12, 4, ENC_BIG_ENDIAN, &etb_topo);
 154     proto_tree_add_item_ret_uint(trdp_tree, hf_trdp_oper_topo, tvb, 16, 4, ENC_BIG_ENDIAN, &opr_topo);
 155     proto_tree_add_item_ret_uint(trdp_tree, hf_trdp_len, tvb, 20, 4, ENC_BIG_ENDIAN, &datalen);
 156
 157     if ( is_pd(msgtype) ) {
 158         proto_tree_add_item(trdp_tree, hf_trdp_res, tvb, 24, 4, ENC_BIG_ENDIAN);
 159         proto_tree_add_item(trdp_tree, hf_trdp_reply_comid, tvb, 28, 4, ENC_BIG_ENDIAN);
 160         proto_tree_add_item(trdp_tree, hf_trdp_reply_ipaddr, tvb, 32, 4, ENC_BIG_ENDIAN);
 161         proto_tree_add_item(trdp_tree, hf_trdp_header_fcs, tvb, 36, 4, ENC_BIG_ENDIAN);
 162     } else {
 163         proto_tree_add_item(trdp_tree, hf_trdp_reply_status, tvb, 24, 4, ENC_BIG_ENDIAN);
 164         proto_tree_add_item(trdp_tree, hf_trdp_session_id, tvb, 28, 16, ENC_BIG_ENDIAN);
 165         uint32_t reply_timeout = tvb_get_uint32(tvb, 44, ENC_BIG_ENDIAN);
 166         proto_tree_add_uint_format_value(trdp_tree, hf_trdp_reply_timeout, tvb, 44, 4, 0, "%d usec", reply_timeout);
 167         proto_tree_add_item(trdp_tree, hf_trdp_source_uri, tvb, 48, 32, ENC_ASCII);
 168         proto_tree_add_item(trdp_tree, hf_trdp_dest_uri, tvb, 80, 32, ENC_ASCII);
 169         proto_tree_add_item(trdp_tree, hf_trdp_header_fcs, tvb, 112, 4, ENC_BIG_ENDIAN);
 170     }
 171     /* Append descriptions */
 172     proto_item_append_text(ti, ", Type: %s, Comid: %d, Seq: %d, ETB Topo: 0x%08x, Opr Topo: 0x%08x", val_to_str(msgtype, msgtype_names_short, "0x%x"), comid, seq, etb_topo, opr_topo);
 173     col_add_fstr(pinfo->cinfo, COL_INFO, "Type=%s Comid=%d Seq=%d", val_to_str(msgtype, msgtype_names_short, "0x%x"), comid, seq);
 174
 175     /* Extract possible padding */
 176     remaining = tvb_captured_length_remaining(tvb, header_len);
 177     if (remaining - datalen > 0)
 178     {
 179         proto_tree_add_item(trdp_tree, hf_trdp_padding, tvb, header_len+datalen, -1, ENC_NA);
 180         proto_tree_set_appendix(trdp_tree, tvb, header_len+datalen, remaining-datalen);
 181     }
 182
 183     /* If this protocol has a sub-dissector call it here, see section 1.8 of
 184      * README.dissector for more information. */
 185
 186     next_tvb = tvb_new_subset_length(tvb, header_len, datalen);
 187     if (!dissector_try_uint(trdp_dissector_table, comid, next_tvb, pinfo, tree))
 188     {
 189         call_dissector(data_handle, next_tvb, pinfo, tree);
 190     }
 191
 192     /* Return the amount of data this dissector was able to dissect (which may
 193      * or may not be the total captured packet as we return here). */
 194     return tvb_captured_length(tvb);
 195 }
 196
 197 static unsigned get_trdp_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset _U_, void *data _U_)
 198 {
 199     uint32_t plen;
 200
 201     plen = tvb_get_uint32(tvb, 20, ENC_BIG_ENDIAN);
 202
 203     return TRDP_MD_HEADER_LEN + plen;
 204 }
 205
 206 static int dissect_trdp_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
 207 {
 208     /* Only Message Data over TCP */
 209     if (!tvb_bytes_exist(tvb, 0, TRDP_MD_HEADER_LEN))
 210         return 0;
 211
 212     tcp_dissect_pdus(tvb, pinfo, tree, true, TRDP_MD_HEADER_LEN,
 213                      get_trdp_pdu_len, dissect_trdp, data);
 214     return tvb_reported_length(tvb);
 215 }
 216
 217 void proto_register_trdp(void)
 218 {
 219     static hf_register_info hf[] = {
 220         /* PD header */
 221         { &hf_trdp_seq,
 222           { "Sequence Counter", "trdp.seq", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }
 223         },
 224         { &hf_trdp_ver,
 225           { "Protocol Version", "trdp.ver", FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }
 226         },
 227         { &hf_trdp_msgtype,
 228           { "Message Type", "trdp.msgtype", FT_UINT16, BASE_HEX, VALS(msgtype_names), 0, NULL, HFILL }
 229         },
 230         { &hf_trdp_comid,
 231           { "Communication Identifier", "trdp.comid", FT_UINT32, BASE_DEC, VALS(comid_names), 0, NULL, HFILL }
 232         },
 233         { &hf_trdp_etb_topo,
 234           { "ETB Topography Counter", "trdp.etb_topo", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }
 235         },
 236         { &hf_trdp_oper_topo,
 237           { "Operational Topography Counter", "trdp.oper_topo", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }
 238         },
 239         { &hf_trdp_len,
 240           { "Dataset Length", "trdp.len", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }
 241         },
 242         { &hf_trdp_res,
 243           { "Reserved", "trdp.res", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }
 244         },
 245         { &hf_trdp_reply_comid,
 246           { "Reply Communication Identifier", "trdp.reply_comid", FT_UINT32, BASE_DEC, VALS(comid_names), 0, NULL, HFILL }
 247         },
 248         { &hf_trdp_reply_ipaddr,
 249           { "Reply IP address", "trdp.reply_ipaddr", FT_IPv4, BASE_NONE, NULL, 0, NULL, HFILL }
 250         },
 251         { &hf_trdp_header_fcs,
 252           { "Header FCS", "trdp.fcs", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }
 253         },
 254         { &hf_trdp_padding,
 255           { "Padding", "trdp.padding", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
 256         },
 257
 258         /* MD Header */
 259         { &hf_trdp_reply_status,
 260           { "Reply Status Indication", "trdp.reply_status", FT_INT32, BASE_DEC, VALS(reply_status_names), 0, NULL, HFILL }
 261         },
 262         { &hf_trdp_session_id,
 263           { "Session UUID", "trdp.session_id", FT_GUID, BASE_NONE, NULL, 0, NULL, HFILL }
 264         },
 265         { &hf_trdp_reply_timeout,
 266           { "Reply Timeout", "trdp.reply_timeout", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }
 267         },
 268         { &hf_trdp_source_uri,
 269           { "Source URI", "trdp.source_uri", FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL }
 270         },
 271         { &hf_trdp_dest_uri,
 272           { "Destination URI", "trdp.dest_uri", FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL }
 273         }
 274     };
 275
 276     /* Setup protocol subtree array */
 277     static int *ett[] = {
 278         &ett_trdp
 279     };
 280
 281     /* Register the protocol name and description */
 282     proto_trdp = proto_register_protocol("Train Realtime Data Protocol", "TRDP", "trdp");
 283
 284     /* Required function calls to register the header fields and subtrees */
 285     proto_register_field_array(proto_trdp, hf, array_length(hf));
 286     proto_register_subtree_array(ett, array_length(ett));
 287
 288     /* Register next dissector */
 289     trdp_dissector_table = register_dissector_table("trdp.comid", "comid", proto_trdp, FT_UINT32, BASE_DEC);
 290 }
 291
 292 void proto_reg_handoff_trdp(void)
 293 {
 294     static dissector_handle_t trdp_handle, trdp_tcp_handle;
 295
 296     trdp_handle = create_dissector_handle(dissect_trdp, proto_trdp);
 297     trdp_tcp_handle = create_dissector_handle(dissect_trdp_tcp, proto_trdp);
 298     dissector_add_uint("udp.port", TRDP_PD_UDP_PORT, trdp_handle);
 299     dissector_add_uint("udp.port", TRDP_MD_TCP_UDP_PORT, trdp_handle);
 300     dissector_add_uint("tcp.port", TRDP_MD_TCP_UDP_PORT, trdp_tcp_handle);
 301
 302     data_handle = find_dissector_add_dependency("data", proto_trdp);
 303 }
 304
 305
 306 /*
 307  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 308  *
 309  * Local variables:
 310  * c-basic-offset: 4
 311  * tab-width: 8
 312  * indent-tabs-mode: nil
 313  * End:
 314  *
 315  * vi: set shiftwidth=4 tabstop=8 expandtab:
 316  * :indentSize=4:tabSize=8:noTabs=true:
 317  */