epan/dissectors/packet-rtacser.c

   1 /* packet-rtacser.c
   2  * Routines for Schweitzer Engineering Laboratories "Real-Time Automation Controller" (RTAC) Serial Line Dissection
   3  * By Chris Bontje (cbontje[AT]gmail.com)
   4  * Copyright May 2013
   5  *
   6  ************************************************************************************************
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * SPDX-License-Identifier: GPL-2.0-or-later
  12  *
  13  ************************************************************************************************
  14  * Dissector Notes:
  15  *
  16  * The RTAC product family (SEL-3530, SEL-2241, SEL-3505) is a Linux-based Automation Controller
  17  * product that is capable of interfacing with SEL and 3rd-party equipment using a variety of
  18  * standard industrial protocols such as SEL FM, DNP3, Modbus, C37.118, Telegyr 8979 and others.
  19  * Each protocol instance (master/client or slave/server) is configured to utilize either Ethernet
  20  * or EIA-232/485 serial connectivity with protocol variations for each medium taken into account.
  21  *
  22  * The configuration software for the RTAC platform is named AcSELerator RTAC (SEL-5033) and
  23  * is used to set up all communications and user logic for the controller as well as provide
  24  * downloading and online debugging facilities.  One particularly useful aspect of the online
  25  * debugging capabilities is a robust Communication Monitor tool that can show raw data streams
  26  * from either serial or Ethernet interfaces.  Many similar products have this same capability
  27  * but the RTAC software goes a step beyond by providing a "save-as" function to save all captured
  28  * data into pcap format for further analysis in Wireshark.
  29  *
  30  * All Ethernet-style capture files will have a packets with a "Linux Cooked Capture" header
  31  * including the "source" MAC address of the device responsible for the generation of the message
  32  * and the TCP/IP header(s) maintained from the original conversation.  The application data from the
  33  * message will follow as per a standard Wireshark packet.
  34  *
  35  * Serial-based pcap capture files were originally stored using "User 0" DLT type 147 to specify a
  36  * user-defined dissector for pcap data but this format was later modified to specify a custom DLT type
  37  * known as LINKTYPE_RTAC_SERIAL (DLT 250). The pcap file data portion contains a standard 12-byte serial
  38  * header followed by the application payload data from actual rx/tx activity on the line.  Some useful
  39  * information can be retrieved from the 12-byte header information, such as conversation time-stamps,
  40  * UART function and EIA-232 serial control line states at the time of the message.
  41  *
  42  * This dissector will automatically be used for any newer-style DLT 250 files, and the payload protocol
  43  * can be configured via built-in preferences to use whatever standardized industrial protocol is present
  44  * on the line for attempted dissection (selfm, mbrtu, dnp3.udp, synphasor).  Older pcap files of DLT type 147
  45  * can be used by setting the DLT_USER preferences configuration of User 0 (DLT=147) with a 'Header Size'
  46  * of '12' and a 'Header Protocol' of 'rtacser'.  The payload protocol should be set to use the protocol
  47  * dissector for the data that is present on the line (again, selfm, mbrtu, dnp3.udp or synphasor). */
  48
  49 #include "config.h"
  50
  51 #include <epan/packet.h>
  52 #include <epan/prefs.h>
  53 #include <epan/decode_as.h>
  54 #include <wiretap/wtap.h>
  55
  56 void proto_register_rtacser(void);
  57
  58 /* Initialize the protocol and registered fields */
  59 static int proto_rtacser;
  60 static int hf_rtacser_timestamp;
  61 static int hf_rtacser_event_type;
  62 static int hf_rtacser_ctrl_cts;
  63 static int hf_rtacser_ctrl_dcd;
  64 static int hf_rtacser_ctrl_dsr;
  65 static int hf_rtacser_ctrl_rts;
  66 static int hf_rtacser_ctrl_dtr;
  67 static int hf_rtacser_ctrl_ring;
  68 static int hf_rtacser_ctrl_mbok;
  69 static int hf_rtacser_footer;
  70
  71 /* Initialize the subtree pointers */
  72 static int ett_rtacser;
  73 static int ett_rtacser_cl;
  74
  75 static dissector_handle_t rtacser_handle;
  76 static dissector_table_t  subdissector_table;
  77
  78 #define RTACSER_HEADER_LEN    12
  79
  80 /* Bit-masks for EIA-232 serial control lines */
  81 #define RTACSER_CTRL_CTS      0x01
  82 #define RTACSER_CTRL_DCD      0x02
  83 #define RTACSER_CTRL_DSR      0x04
  84 #define RTACSER_CTRL_RTS      0x08
  85 #define RTACSER_CTRL_DTR      0x10
  86 #define RTACSER_CTRL_RING     0x20
  87 #define RTACSER_CTRL_MBOK     0x40
  88
  89 /* Event Types */
  90 static const value_string rtacser_eventtype_vals[] = {
  91     { 0x00,       "STATUS_CHANGE"         },
  92     { 0x01,       "DATA_TX_START"         },
  93     { 0x02,       "DATA_RX_START"         },
  94     { 0x03,       "DATA_TX_END"           },
  95     { 0x04,       "DATA_RX_END"           },
  96     { 0x05,       "CAPTURE_DATA_LOST"     },
  97     { 0x06,       "CAPTURE_COMPLETE"      },
  98     { 0x07,       "FRAMING_ERROR"         },
  99     { 0x08,       "PARITY_ERROR"          },
 100     { 0x09,       "SERIAL_BREAK_EVENT"    },
 101     { 0x0A,       "SERIAL_OVERFLOW_EVENT" },
 102     { 0,          NULL }
 103 };
 104
 105 static void
 106 rtacser_ppi_prompt(packet_info *pinfo _U_, char* result)
 107 {
 108     snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Payload as");
 109 }
 110
 111 /******************************************************************************************************/
 112 /* Code to dissect RTAC Serial-Line Protocol packets */
 113 /******************************************************************************************************/
 114 static void
 115 dissect_rtacser_data(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 116 {
 117 /* Set up structures needed to add the protocol subtree and manage it */
 118     proto_item    *rtacser_item, *cl_item;
 119     proto_tree    *rtacser_tree, *cl_tree;
 120     int           offset = 0, len;
 121     unsigned      event_type;
 122     bool          cts, dcd, dsr, rts, dtr, ring, mbok;
 123     tvbuff_t      *payload_tvb;
 124
 125     len = RTACSER_HEADER_LEN;
 126
 127     /* Make entries in Protocol column on summary display */
 128     col_set_str(pinfo->cinfo, COL_PROTOCOL, "RTAC Serial");
 129     col_clear(pinfo->cinfo, COL_INFO);
 130
 131     rtacser_item = proto_tree_add_protocol_format(tree, proto_rtacser, tvb, 0, len, "RTAC Serial Line");
 132     rtacser_tree = proto_item_add_subtree(rtacser_item, ett_rtacser);
 133
 134     /* Time-stamp is stored as 2 x 32-bit unsigned integers, the left and right-hand side of the decimal point respectively */
 135     /* The format mirrors the timeval struct - absolute Epoch time (seconds since 1/1/1970) with an added microsecond component */
 136     proto_tree_add_item(rtacser_tree, hf_rtacser_timestamp, tvb, offset, 8, ENC_TIME_SECS_USECS|ENC_BIG_ENDIAN);
 137     offset += 8;
 138
 139     /* Set INFO column with RTAC Serial Event Type */
 140     event_type = tvb_get_uint8(tvb, offset);
 141     col_add_fstr(pinfo->cinfo, COL_INFO, "%-21s", val_to_str_const(event_type, rtacser_eventtype_vals, "Unknown Type"));
 142
 143     /* Add event type to tree */
 144     proto_tree_add_item(rtacser_tree, hf_rtacser_event_type, tvb, offset, 1, ENC_BIG_ENDIAN);
 145     offset += 1;
 146
 147     /* Retrieve EIA-232 serial control line states */
 148     cts  = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_CTS;
 149     dcd  = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_DCD;
 150     dsr  = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_DSR;
 151     rts  = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_RTS;
 152     dtr  = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_DTR;
 153     ring = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_RING;
 154     mbok = tvb_get_uint8(tvb, offset) & RTACSER_CTRL_MBOK;
 155
 156     cl_tree = proto_tree_add_subtree(rtacser_tree, tvb, offset, 1, ett_rtacser_cl, &cl_item, "Control Lines");
 157
 158     /* Add UART Control Line information to INFO column */
 159     col_append_str(pinfo->cinfo, COL_INFO, " ( ");
 160     (cts)  ? col_append_str(pinfo->cinfo, COL_INFO, "CTS") : col_append_str(pinfo->cinfo, COL_INFO, "/CTS");
 161     (dcd)  ? col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "DCD")  : col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "/DCD");
 162     (dsr)  ? col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "DSR")  : col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "/DSR");
 163     (rts)  ? col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "RTS")  : col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "/RTS");
 164     (dtr)  ? col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "DTR")  : col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "/DTR");
 165     (ring) ? col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "RING") : col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "/RING");
 166     (mbok) ? col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "MBOK") : col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "/MBOK");
 167     col_append_str(pinfo->cinfo, COL_INFO, " )");
 168
 169     /* Add UART Control Line information to tree */
 170     proto_item_append_text(cl_item, " (");
 171     (cts)  ? proto_item_append_text(cl_item, "CTS, ") : proto_item_append_text(cl_item, "/CTS, ");
 172     (dcd)  ? proto_item_append_text(cl_item, "DCD, ") : proto_item_append_text(cl_item, "/DCD, ");
 173     (dsr)  ? proto_item_append_text(cl_item, "DSR, ") : proto_item_append_text(cl_item, "/DSR, ");
 174     (rts)  ? proto_item_append_text(cl_item, "RTS, ") : proto_item_append_text(cl_item, "/RTS, ");
 175     (dtr)  ? proto_item_append_text(cl_item, "DTR, ") : proto_item_append_text(cl_item, "/DTR, ");
 176     (ring) ? proto_item_append_text(cl_item, "RING, ") : proto_item_append_text(cl_item, "/RING, ");
 177     (mbok) ? proto_item_append_text(cl_item, "MBOK") : proto_item_append_text(cl_item, "/MBOK");
 178     proto_item_append_text(cl_item, ")");
 179
 180     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_cts,  tvb, offset, 1, ENC_BIG_ENDIAN);
 181     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_dcd,  tvb, offset, 1, ENC_BIG_ENDIAN);
 182     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_dsr,  tvb, offset, 1, ENC_BIG_ENDIAN);
 183     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_rts,  tvb, offset, 1, ENC_BIG_ENDIAN);
 184     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_dtr,  tvb, offset, 1, ENC_BIG_ENDIAN);
 185     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_ring, tvb, offset, 1, ENC_BIG_ENDIAN);
 186     proto_tree_add_item(cl_tree, hf_rtacser_ctrl_mbok, tvb, offset, 1, ENC_BIG_ENDIAN);
 187     offset += 1;
 188
 189     /* 2-byte footer */
 190     proto_tree_add_item(rtacser_tree, hf_rtacser_footer, tvb, offset, 2, ENC_BIG_ENDIAN);
 191     offset += 2;
 192
 193     if (tvb_reported_length_remaining(tvb, offset) > 0) {
 194         payload_tvb = tvb_new_subset_remaining(tvb, RTACSER_HEADER_LEN);
 195
 196         if (!dissector_try_payload_with_data(subdissector_table, payload_tvb, pinfo, tree, true, NULL)){
 197             call_data_dissector(payload_tvb, pinfo, tree);
 198         }
 199     }
 200 }
 201
 202
 203
 204 /******************************************************************************************************/
 205 /* Dissect RTAC Serial-line protocol payload */
 206 /******************************************************************************************************/
 207 static int
 208 dissect_rtacser(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
 209 {
 210     int length = tvb_captured_length(tvb);
 211
 212     /* Check for a RTAC Serial packet.  It should be at least 12 bytes */
 213     if(length < 12) {
 214
 215         return 0;
 216     }
 217
 218     dissect_rtacser_data(tvb, pinfo, tree);
 219
 220     return tvb_captured_length(tvb);
 221 }
 222
 223 /******************************************************************************************************/
 224 /* Register the protocol with Wireshark */
 225 /******************************************************************************************************/
 226 void proto_reg_handoff_rtacser(void);
 227
 228 void
 229 proto_register_rtacser(void)
 230 {
 231     /* RTAC Serial Protocol header fields */
 232     static hf_register_info rtacser_hf[] = {
 233         { &hf_rtacser_timestamp,
 234         { "Arrived At Time", "rtacser.timestamp", FT_RELATIVE_TIME, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 235         { &hf_rtacser_event_type,
 236         { "Event Type", "rtacser.eventtype", FT_UINT8, BASE_HEX, VALS(rtacser_eventtype_vals), 0x0, NULL, HFILL }},
 237         { &hf_rtacser_ctrl_cts,
 238         { "CTS", "rtacser.cts", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_CTS, NULL, HFILL }},
 239         { &hf_rtacser_ctrl_dcd,
 240         { "DCD", "rtacser.dcd", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_DCD, NULL, HFILL }},
 241         { &hf_rtacser_ctrl_dsr,
 242         { "DSR", "rtacser.dsr", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_DSR, NULL, HFILL }},
 243         { &hf_rtacser_ctrl_rts,
 244         { "RTS", "rtacser.rts", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_RTS, NULL, HFILL }},
 245         { &hf_rtacser_ctrl_dtr,
 246         { "DTR", "rtacser.dtr", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_DTR, NULL, HFILL }},
 247         { &hf_rtacser_ctrl_ring,
 248         { "RING", "rtacser.ring", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_RING, NULL, HFILL }},
 249         { &hf_rtacser_ctrl_mbok,
 250         { "MBOK", "rtacser.mbok", FT_UINT8, BASE_DEC, NULL, RTACSER_CTRL_MBOK, NULL, HFILL }},
 251         { &hf_rtacser_footer,
 252         { "Footer", "rtacser.footer", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
 253     };
 254
 255     /* Setup protocol subtree array */
 256     static int *ett[] = {
 257         &ett_rtacser,
 258         &ett_rtacser_cl,
 259     };
 260
 261     module_t *rtacser_module;
 262
 263     /* Register the protocol name and description */
 264     proto_rtacser = proto_register_protocol("RTAC Serial", "RTAC Serial", "rtacser");
 265
 266     /* Registering protocol to be called by another dissector */
 267     rtacser_handle = register_dissector("rtacser", dissect_rtacser, proto_rtacser);
 268
 269     /* Required function calls to register the header fields and subtrees used */
 270     proto_register_field_array(proto_rtacser, rtacser_hf, array_length(rtacser_hf));
 271     proto_register_subtree_array(ett, array_length(ett));
 272
 273     /* Register required preferences for RTAC Serial Payload Protocol */
 274     rtacser_module = prefs_register_protocol_obsolete(proto_rtacser);
 275
 276     /* RTAC Serial Preference - Payload Protocol in use */
 277     prefs_register_obsolete_preference(rtacser_module, "rtacserial_payload_proto");
 278
 279     subdissector_table = register_decode_as_next_proto(proto_rtacser, "rtacser.data",
 280                                                        "RTAC Serial Data Subdissector", rtacser_ppi_prompt);
 281 }
 282
 283 /******************************************************************************************************/
 284 /* If this dissector uses sub-dissector registration add a registration routine.
 285    This format is required because a script is used to find these routines and
 286    create the code that calls these routines.
 287  */
 288 /******************************************************************************************************/
 289 void
 290 proto_reg_handoff_rtacser(void)
 291 {
 292     dissector_add_uint("wtap_encap", WTAP_ENCAP_RTAC_SERIAL, rtacser_handle);
 293 }
 294
 295 /*
 296  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 297  *
 298  * Local variables:
 299  * c-basic-offset: 4
 300  * tab-width: 8
 301  * indent-tabs-mode: nil
 302  * End:
 303  *
 304  * vi: set shiftwidth=4 tabstop=8 expandtab:
 305  * :indentSize=4:tabSize=8:noTabs=true:
 306  */