epan/dissectors/packet-fefd.c

   1 /* packet-fefd.c
   2  * Routines for the disassembly of the "Far End Failure Detection"
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * Copied from packet-udld.c
  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 <epan/packet.h>
  30 #include <epan/strutil.h>
  31
  32 #include <epan/oui.h>
  33 #include <epan/nlpid.h>
  34
  35
  36
  37 /* Offsets in TLV structure. */
  38 #define TLV_TYPE        0
  39 #define TLV_LENGTH      2
  40
  41 static int proto_fefd = -1;
  42 static int hf_fefd_version = -1;
  43 static int hf_fefd_opcode = -1;
  44 static int hf_fefd_flags = -1;
  45 static int hf_fefd_flags_rt = -1;
  46 static int hf_fefd_flags_rsy = -1;
  47 static int hf_fefd_checksum = -1;
  48 static int hf_fefd_tlvtype = -1;
  49 static int hf_fefd_tlvlength = -1;
  50
  51 static gint ett_fefd = -1;
  52 static gint ett_fefd_flags = -1;
  53 static gint ett_fefd_tlv = -1;
  54
  55 static dissector_handle_t data_handle;
  56
  57 #define TYPE_DEVICE_ID        0x0001
  58 #define TYPE_PORT_ID          0x0002
  59 #define TYPE_ECHO             0x0003
  60 #define TYPE_MESSAGE_INTERVAL 0x0004
  61 #define TYPE_TIMEOUT_INTERVAL 0x0005
  62 #define TYPE_DEVICE_NAME      0x0006
  63 #define TYPE_SEQUENCE_NUMBER  0x0007
  64
  65
  66 static const value_string type_vals[] = {
  67     { TYPE_DEVICE_ID,          "Device ID" },
  68     { TYPE_PORT_ID,            "Port ID" },
  69     { TYPE_ECHO,               "Echo" },
  70     { TYPE_MESSAGE_INTERVAL,   "Message interval" },
  71     { TYPE_TIMEOUT_INTERVAL,   "Timeout interval" },
  72     { TYPE_DEVICE_NAME,        "Device name" },
  73     { TYPE_SEQUENCE_NUMBER,    "Sequence number" },
  74     { 0,                       NULL }
  75 };
  76
  77 #define OPCODE_RESERVED       0x00
  78 #define OPCODE_PROBE          0x01
  79 #define OPCODE_ECHO           0x02
  80 #define OPCODE_FLUSH          0x03
  81
  82 static const value_string opcode_vals[] = {
  83     { OPCODE_RESERVED, "Reserved" },
  84     { OPCODE_PROBE,    "Probe" },
  85     { OPCODE_ECHO,     "Echo" },
  86     { OPCODE_FLUSH,    "Flush" },
  87     { 0,               NULL }
  88 };
  89
  90 static void
  91 dissect_fefd(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  92 {
  93     proto_item *ti;
  94     proto_tree *fefd_tree = NULL;
  95     int         offset    = 0;
  96     guint16     type;
  97     guint16     length;
  98     proto_item *tlvi;
  99     proto_tree *tlv_tree;
 100     int         real_length;
 101
 102     col_set_str(pinfo->cinfo, COL_PROTOCOL, "FEFD");
 103     col_clear(pinfo->cinfo, COL_INFO);
 104
 105     if (tree) {
 106         proto_item *flags_ti;
 107         proto_tree *flags_tree;
 108
 109         ti = proto_tree_add_item(tree, proto_fefd, tvb, offset, -1, ENC_NA);
 110         fefd_tree = proto_item_add_subtree(ti, ett_fefd);
 111
 112         /* FEFD header */
 113         proto_tree_add_item(fefd_tree, hf_fefd_version, tvb, offset, 1, ENC_BIG_ENDIAN);
 114         proto_tree_add_item(fefd_tree, hf_fefd_opcode, tvb, offset, 1, ENC_BIG_ENDIAN);
 115         offset += 1;
 116         flags_ti = proto_tree_add_item(fefd_tree, hf_fefd_flags, tvb, offset, 1, ENC_BIG_ENDIAN);
 117         flags_tree = proto_item_add_subtree(flags_ti, ett_fefd_flags);
 118         proto_tree_add_item(flags_tree, hf_fefd_flags_rt, tvb, offset, 1, ENC_BIG_ENDIAN);
 119         proto_tree_add_item(flags_tree, hf_fefd_flags_rsy, tvb, offset, 1, ENC_BIG_ENDIAN);
 120         offset += 1;
 121         proto_tree_add_item(fefd_tree, hf_fefd_checksum, tvb, offset, 2, ENC_BIG_ENDIAN);
 122         offset += 2;
 123     } else {
 124         offset += 4; /* The version/opcode/flags/checksum fields from above */
 125     }
 126
 127     while (tvb_reported_length_remaining(tvb, offset) != 0) {
 128         type = tvb_get_ntohs(tvb, offset + TLV_TYPE);
 129         length = tvb_get_ntohs(tvb, offset + TLV_LENGTH);
 130         if (length < 4) {
 131             if (tree) {
 132                 tlvi = proto_tree_add_text(fefd_tree, tvb, offset, 4,
 133                                            "TLV with invalid length %u (< 4)",
 134                                            length);
 135                 tlv_tree = proto_item_add_subtree(tlvi, ett_fefd_tlv);
 136                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 137                                     offset + TLV_TYPE, 2, type);
 138                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 139                                     offset + TLV_LENGTH, 2, length);
 140             }
 141             offset += 4;
 142             break;
 143         }
 144
 145         switch (type) {
 146
 147         case TYPE_DEVICE_ID:
 148             /* Device ID */
 149
 150             col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL,
 151                                     "Device ID: %s",
 152                                     tvb_format_stringzpad(tvb, offset + 4,
 153                                                           length - 4));
 154
 155             if (tree) {
 156                 tlvi = proto_tree_add_text(fefd_tree, tvb, offset,
 157                                            length, "Device ID: %s",
 158                                            tvb_format_stringzpad(tvb, offset + 4, length - 4));
 159                 tlv_tree = proto_item_add_subtree(tlvi, ett_fefd_tlv);
 160                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 161                                     offset + TLV_TYPE, 2, type);
 162                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 163                                     offset + TLV_LENGTH, 2, length);
 164                 proto_tree_add_text(tlv_tree, tvb, offset + 4,
 165                                     length - 4, "Device ID: %s",
 166                                     tvb_format_stringzpad(tvb, offset + 4, length - 4));
 167             }
 168             offset += length;
 169             break;
 170
 171         case TYPE_PORT_ID:
 172             real_length = length;
 173             if (tvb_get_guint8(tvb, offset + real_length) != 0x00) {
 174                 /* The length in the TLV doesn't appear to be the
 175                    length of the TLV, as the byte just past it
 176                    isn't the first byte of a 2-byte big-endian
 177                    small integer; make the length of the TLV the length
 178                    in the TLV, plus 4 bytes for the TLV type and length,
 179                    minus 1 because that's what makes one capture work. */
 180                 real_length = length + 3;
 181             }
 182
 183             col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL,
 184                                     "Port ID: %s",
 185                                     tvb_format_stringzpad(tvb, offset + 4, real_length - 4));
 186
 187             if (tree) {
 188                 tlvi = proto_tree_add_text(fefd_tree, tvb, offset,
 189                                            real_length, "Port ID: %s",
 190                                            tvb_format_text(tvb, offset + 4, real_length - 4));
 191                 tlv_tree = proto_item_add_subtree(tlvi, ett_fefd_tlv);
 192                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 193                                     offset + TLV_TYPE, 2, type);
 194                 proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 195                                     offset + TLV_LENGTH, 2, length);
 196                 proto_tree_add_text(tlv_tree, tvb, offset + 4,
 197                                     real_length - 4,
 198                                     "Sent through Interface: %s",
 199                                     tvb_format_text(tvb, offset + 4, real_length - 4));
 200             }
 201             offset += real_length;
 202             break;
 203
 204         case TYPE_ECHO:
 205         case TYPE_MESSAGE_INTERVAL:
 206         case TYPE_TIMEOUT_INTERVAL:
 207         case TYPE_DEVICE_NAME:
 208         case TYPE_SEQUENCE_NUMBER:
 209         default:
 210             tlvi = proto_tree_add_text(fefd_tree, tvb, offset,
 211                                        length, "Type: %s, length: %u",
 212                                        val_to_str(type, type_vals, "Unknown (0x%04x)"),
 213                                        length);
 214             tlv_tree = proto_item_add_subtree(tlvi, ett_fefd_tlv);
 215             proto_tree_add_uint(tlv_tree, hf_fefd_tlvtype, tvb,
 216                                 offset + TLV_TYPE, 2, type);
 217             proto_tree_add_uint(tlv_tree, hf_fefd_tlvlength, tvb,
 218                                 offset + TLV_LENGTH, 2, length);
 219             if (length > 4) {
 220                 proto_tree_add_text(tlv_tree, tvb, offset + 4,
 221                                     length - 4, "Data");
 222             } else {
 223                 return;
 224             }
 225             offset += length;
 226         }
 227     }
 228
 229     call_dissector(data_handle, tvb_new_subset_remaining(tvb, offset), pinfo, fefd_tree);
 230 }
 231
 232 void
 233 proto_register_fefd(void)
 234 {
 235     static hf_register_info hf[] = {
 236         { &hf_fefd_version,
 237           { "Version",          "fefd.version",  FT_UINT8, BASE_DEC, NULL, 0xE0,
 238             NULL, HFILL }},
 239
 240         { &hf_fefd_opcode,
 241           { "Opcode",           "fefd.opcode", FT_UINT8, BASE_DEC, VALS(opcode_vals), 0x1F,
 242             NULL, HFILL }},
 243
 244         { &hf_fefd_flags,
 245           { "Flags",            "fefd.flags", FT_UINT8, BASE_HEX, NULL, 0x0,
 246             NULL, HFILL }},
 247
 248         { &hf_fefd_flags_rt,
 249           { "Recommended timeout",              "fefd.flags.rt", FT_BOOLEAN, 8, NULL, 0x80,
 250             NULL, HFILL }},
 251
 252         { &hf_fefd_flags_rsy,
 253           { "ReSynch",          "fefd.flags.rsy", FT_BOOLEAN, 8, NULL, 0x40,
 254             NULL, HFILL }},
 255
 256         { &hf_fefd_checksum,
 257           { "Checksum",         "fefd.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
 258             NULL, HFILL }},
 259
 260         { &hf_fefd_tlvtype,
 261           { "Type",             "fefd.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0,
 262             NULL, HFILL }},
 263
 264         { &hf_fefd_tlvlength,
 265           { "Length",           "fefd.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0,
 266             NULL, HFILL }}
 267     };
 268     static gint *ett[] = {
 269         &ett_fefd,
 270         &ett_fefd_flags,
 271         &ett_fefd_tlv
 272     };
 273
 274     proto_fefd = proto_register_protocol("Far End Failure Detection", "FEFD", "fefd");
 275     proto_register_field_array(proto_fefd, hf, array_length(hf));
 276     proto_register_subtree_array(ett, array_length(ett));
 277 }
 278
 279 void
 280 proto_reg_handoff_fefd(void)
 281 {
 282     dissector_handle_t fefd_handle;
 283
 284     data_handle = find_dissector("data");
 285     fefd_handle = create_dissector_handle(dissect_fefd, proto_fefd);
 286     dissector_add_uint("llc.force10_pid", 0x0111, fefd_handle);
 287 }