epan/dissectors/packet-fefd.c

   1 /* packet-fefd.c
   2  * Routines for the disassembly of the "Far End Failure Detection"
   3  *
   4  * Wireshark - Network traffic analyzer
   5  * By Gerald Combs <gerald@wireshark.org>
   6  * Copyright 1998 Gerald Combs
   7  *
   8  * Copied from packet-udld.c
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  */
  12
  13 #include "config.h"
  14
  15 #include <epan/packet.h>
  16
  17
  18 void proto_register_fefd(void);
  19 void proto_reg_handoff_fefd(void);
  20
  21 static dissector_handle_t fefd_handle;
  22
  23 /* Offsets in TLV structure. */
  24 #define TLV_TYPE        0
  25 #define TLV_LENGTH      2
  26
  27 static int proto_fefd;
  28 static int hf_fefd_version;
  29 static int hf_fefd_opcode;
  30 static int hf_fefd_flags;
  31 static int hf_fefd_flags_rt;
  32 static int hf_fefd_flags_rsy;
  33 static int hf_fefd_checksum;
  34 static int hf_fefd_tlvtype;
  35 static int hf_fefd_tlvlength;
  36 static int hf_fefd_device_id;
  37 static int hf_fefd_sent_through_interface;
  38 static int hf_fefd_data;
  39
  40 static int ett_fefd;
  41 static int ett_fefd_flags;
  42 static int ett_fefd_tlv;
  43
  44 #define TYPE_DEVICE_ID        0x0001
  45 #define TYPE_PORT_ID          0x0002
  46 #define TYPE_ECHO             0x0003
  47 #define TYPE_MESSAGE_INTERVAL 0x0004
  48 #define TYPE_TIMEOUT_INTERVAL 0x0005
  49 #define TYPE_DEVICE_NAME      0x0006
  50 #define TYPE_SEQUENCE_NUMBER  0x0007
  51
  52
  53 static const value_string type_vals[] = {
  54     { TYPE_DEVICE_ID,          "Device ID" },
  55     { TYPE_PORT_ID,            "Port ID" },
  56     { TYPE_ECHO,               "Echo" },
  57     { TYPE_MESSAGE_INTERVAL,   "Message interval" },
  58     { TYPE_TIMEOUT_INTERVAL,   "Timeout interval" },
  59     { TYPE_DEVICE_NAME,        "Device name" },
  60     { TYPE_SEQUENCE_NUMBER,    "Sequence number" },
  61     { 0,                       NULL }
  62 };
  63
  64 #define OPCODE_RESERVED       0x00
  65 #define OPCODE_PROBE          0x01
  66 #define OPCODE_ECHO           0x02
  67 #define OPCODE_FLUSH          0x03
  68
  69 static const value_string opcode_vals[] = {
  70     { OPCODE_RESERVED, "Reserved" },
  71     { OPCODE_PROBE,    "Probe" },
  72     { OPCODE_ECHO,     "Echo" },
  73     { OPCODE_FLUSH,    "Flush" },
  74     { 0,               NULL }
  75 };
  76
  77 static int
  78 dissect_fefd(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  79 {
  80     proto_item *ti;
  81     proto_tree *fefd_tree = NULL;
  82     int         offset    = 0;
  83     uint16_t    type;
  84     uint16_t    length;
  85     proto_tree *tlv_tree;
  86     int         real_length;
  87     static int * const flags[] = {
  88         &hf_fefd_flags_rt,
  89         &hf_fefd_flags_rsy,
  90         NULL
  91     };
  92     static int * const headers[] = {
  93         &hf_fefd_version,
  94         &hf_fefd_opcode,
  95         NULL
  96     };
  97
  98     col_set_str(pinfo->cinfo, COL_PROTOCOL, "FEFD");
  99     col_clear(pinfo->cinfo, COL_INFO);
 100
 101     ti = proto_tree_add_item(tree, proto_fefd, tvb, offset, -1, ENC_NA);
 102     fefd_tree = proto_item_add_subtree(ti, ett_fefd);
 103
 104     /* FEFD header */
 105     proto_tree_add_bitmask_list(fefd_tree, tvb, offset, 1, headers, ENC_BIG_ENDIAN);
 106     offset += 1;
 107     proto_tree_add_bitmask(fefd_tree, tvb, offset, hf_fefd_flags, ett_fefd_flags, flags, ENC_BIG_ENDIAN);
 108     offset += 1;
 109     proto_tree_add_checksum(fefd_tree, tvb, offset, hf_fefd_checksum, -1, NULL, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
 110     offset += 2;
 111
 112     while (tvb_reported_length_remaining(tvb, offset) != 0) {
 113         type = tvb_get_ntohs(tvb, offset + TLV_TYPE);
 114         length = tvb_get_ntohs(tvb, offset + TLV_LENGTH);
 115         if (length < 4) {
 116             if (tree) {
 117                 tlv_tree = proto_tree_add_subtree_format(fefd_tree, tvb, offset, 4,  /* XXX - expert info? */
 118                                            ett_fefd_tlv, NULL, "TLV with invalid length %u (< 4)",
 119                                            length);
 120                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 121                                     offset + TLV_TYPE, 2, type);
 122                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 123                                     offset + TLV_LENGTH, 2, length);
 124             }
 125             offset += 4;
 126             break;
 127         }
 128
 129         switch (type) {
 130
 131         case TYPE_DEVICE_ID:
 132             /* Device ID */
 133
 134             col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL,
 135                                     "Device ID: %s",
 136                                     tvb_format_stringzpad(pinfo->pool, tvb, offset + 4,
 137                                                           length - 4));
 138
 139             if (tree) {
 140                 tlv_tree = proto_tree_add_subtree_format(fefd_tree, tvb, offset,
 141                                            length, ett_fefd_tlv, NULL, "Device ID: %s",
 142                                            tvb_format_stringzpad(pinfo->pool, tvb, offset + 4, length - 4));
 143                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 144                                     offset + TLV_TYPE, 2, type);
 145                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 146                                     offset + TLV_LENGTH, 2, length);
 147                 proto_tree_add_item(tlv_tree, hf_fefd_device_id, tvb, offset + 4,
 148                                     length - 4, ENC_NA|ENC_ASCII);
 149             }
 150             offset += length;
 151             break;
 152
 153         case TYPE_PORT_ID:
 154             real_length = length;
 155             if (tvb_get_uint8(tvb, offset + real_length) != 0x00) {
 156                 /* The length in the TLV doesn't appear to be the
 157                    length of the TLV, as the byte just past it
 158                    isn't the first byte of a 2-byte big-endian
 159                    small integer; make the length of the TLV the length
 160                    in the TLV, plus 4 bytes for the TLV type and length,
 161                    minus 1 because that's what makes one capture work. */
 162                 real_length = length + 3;
 163             }
 164
 165             col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL,
 166                                     "Port ID: %s",
 167                                     tvb_format_stringzpad(pinfo->pool, tvb, offset + 4, real_length - 4));
 168
 169             if (tree) {
 170                 tlv_tree = proto_tree_add_subtree_format(fefd_tree, tvb, offset,
 171                                            real_length, ett_fefd_tlv, NULL, "Port ID: %s",
 172                                            tvb_format_text(pinfo->pool, tvb, offset + 4, real_length - 4));
 173                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 174                                     offset + TLV_TYPE, 2, type);
 175                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 176                                     offset + TLV_LENGTH, 2, length);
 177                 proto_tree_add_item(tlv_tree, hf_fefd_sent_through_interface, tvb, offset + 4,
 178                                     real_length - 4, ENC_NA|ENC_ASCII);
 179             }
 180             offset += real_length;
 181             break;
 182
 183         case TYPE_ECHO:
 184         case TYPE_MESSAGE_INTERVAL:
 185         case TYPE_TIMEOUT_INTERVAL:
 186         case TYPE_DEVICE_NAME:
 187         case TYPE_SEQUENCE_NUMBER:
 188         default:
 189             tlv_tree = proto_tree_add_subtree_format(fefd_tree, tvb, offset,
 190                                        length, ett_fefd_tlv, NULL, "Type: %s, length: %u",
 191                                        val_to_str(type, type_vals, "Unknown (0x%04x)"),
 192                                        length);
 193             proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 194                                 offset + TLV_TYPE, 2, type);
 195             proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 196                                 offset + TLV_LENGTH, 2, length);
 197             if (length > 4) {
 198                 proto_tree_add_item(tlv_tree, hf_fefd_data, tvb, offset + 4,
 199                                     length - 4, ENC_NA);
 200             } else {
 201                 return tvb_captured_length(tvb);
 202             }
 203             offset += length;
 204         }
 205     }
 206
 207     call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, fefd_tree);
 208     return tvb_captured_length(tvb);
 209 }
 210
 211 void
 212 proto_register_fefd(void)
 213 {
 214     static hf_register_info hf[] = {
 215         { &hf_fefd_version,
 216           { "Version",          "fefd.version",  FT_UINT8, BASE_DEC, NULL, 0xE0,
 217             NULL, HFILL }},
 218
 219         { &hf_fefd_opcode,
 220           { "Opcode",           "fefd.opcode", FT_UINT8, BASE_DEC, VALS(opcode_vals), 0x1F,
 221             NULL, HFILL }},
 222
 223         { &hf_fefd_flags,
 224           { "Flags",            "fefd.flags", FT_UINT8, BASE_HEX, NULL, 0x0,
 225             NULL, HFILL }},
 226
 227         { &hf_fefd_flags_rt,
 228           { "Recommended timeout",              "fefd.flags.rt", FT_BOOLEAN, 8, NULL, 0x80,
 229             NULL, HFILL }},
 230
 231         { &hf_fefd_flags_rsy,
 232           { "ReSynch",          "fefd.flags.rsy", FT_BOOLEAN, 8, NULL, 0x40,
 233             NULL, HFILL }},
 234
 235         { &hf_fefd_checksum,
 236           { "Checksum",         "fefd.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
 237             NULL, HFILL }},
 238
 239         { &hf_fefd_tlvtype,
 240           { "Type",             "fefd.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0,
 241             NULL, HFILL }},
 242
 243         { &hf_fefd_tlvlength,
 244           { "Length",           "fefd.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0,
 245             NULL, HFILL }},
 246
 247         { &hf_fefd_device_id,
 248           { "Device ID",           "fefd.device_id", FT_STRINGZ, BASE_NONE, NULL, 0x0,
 249             NULL, HFILL }},
 250
 251         { &hf_fefd_sent_through_interface,
 252           { "Sent through Interface",  "fefd.sent_through_interface", FT_STRING, BASE_NONE, NULL, 0x0,
 253             NULL, HFILL }},
 254
 255         { &hf_fefd_data,
 256           { "Data",  "fefd.data", FT_BYTES, BASE_NONE, NULL, 0x0,
 257             NULL, HFILL }},
 258     };
 259
 260     static int *ett[] = {
 261         &ett_fefd,
 262         &ett_fefd_flags,
 263         &ett_fefd_tlv
 264     };
 265
 266     proto_fefd = proto_register_protocol("Far End Failure Detection", "FEFD", "fefd");
 267     proto_register_field_array(proto_fefd, hf, array_length(hf));
 268     proto_register_subtree_array(ett, array_length(ett));
 269
 270     fefd_handle = register_dissector("fefd", dissect_fefd, proto_fefd);
 271 }
 272
 273 void
 274 proto_reg_handoff_fefd(void)
 275 {
 276     dissector_add_uint("llc.force10_pid", 0x0111, fefd_handle);
 277 }
 278
 279 /*
 280  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 281  *
 282  * Local variables:
 283  * c-basic-offset: 4
 284  * tab-width: 8
 285  * indent-tabs-mode: nil
 286  * End:
 287  *
 288  * vi: set shiftwidth=4 tabstop=8 expandtab:
 289  * :indentSize=4:tabSize=8:noTabs=true:
 290  */