packet-bfd.c

   1 /* packet-bfd.c
   2  * Routines for Bi-directional Fault Detection (BFD) message dissection
   3  *
   4  * Copyright 2003, Hannes Gredler <hannes@juniper.net>
   5  *
   6  * $Id: packet-bfd.c,v 1.1 2003/11/23 22:00:48 gerald Exp $
   7  *
   8  * Ethereal - Network traffic analyzer
   9  * By Gerald Combs <gerald@ethereal.com>
  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 <stdio.h>
  32 #include <stdlib.h>
  33 #include <ctype.h>
  34
  35 #include <string.h>
  36 #include <glib.h>
  37 #include <epan/packet.h>
  38
  39 #define UDP_PORT_BFD_CONTROL 3784 /* draft-katz-ward-bfd-v4v6-1hop-00.txt */
  40
  41 static const value_string bfd_control_diag_values[] = {
  42     { 0, "No Diagnostic" },
  43     { 1, "Control Detection Time Expired" },
  44     { 2, "Echo Function Failed" },
  45     { 3, "Neighbor Signaled Session Down" },
  46     { 4, "Forwarding Plane Reset" },
  47     { 5, "Path Down" },
  48     { 6, "Concatenated Path Down" },
  49     { 7, "Administratively Down" },
  50     { 0, NULL }
  51 };
  52
  53 static const value_string bfd_control_flag_values[] = {
  54     { 0x80,     "I Hear You" },
  55     { 0x40,     "Demand" },
  56     { 0x20,     "Poll" },
  57     { 0x10,     "Final" },
  58     { 0x08,     "Reserved" },
  59     { 0x04,     "Reserved" },
  60     { 0x02,     "Reserved" },
  61     { 0x01,     "Reserved" },
  62     { 0, NULL }
  63 };
  64
  65 static gint proto_bfd = -1;
  66
  67 static gint hf_bfd_version = -1;
  68 static gint hf_bfd_diag = -1;
  69 static gint hf_bfd_flags = -1;
  70 static gint hf_bfd_detect_time_multiplier = -1;
  71 static gint hf_bfd_my_discriminator = -1;
  72 static gint hf_bfd_your_discriminator = -1;
  73 static gint hf_bfd_desired_min_tx_interval = -1;
  74 static gint hf_bfd_required_min_rx_interval = -1;
  75 static gint hf_bfd_required_min_echo_interval = -1;
  76
  77 static gint ett_bfd = -1;
  78
  79 /*
  80  * Control packet, draft-katz-ward-bfd-01.txt
  81  *
  82  *     0                   1                   2                   3
  83  *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  84  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  85  *    |Vers |  Diag   |H|D|P|F| Rsvd  |  Detect Mult  |    Length     |
  86  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  87  *    |                       My Discriminator                        |
  88  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  89  *    |                      Your Discriminator                       |
  90  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  91  *    |                    Desired Min TX Interval                    |
  92  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93  *    |                   Required Min RX Interval                    |
  94  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95  *    |                 Required Min Echo RX Interval                 |
  96  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  97  */
  98
  99 static void dissect_bfd_control(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 100 {
 101     gint bfd_version = -1;
 102     gint bfd_diag = -1;
 103     gint bfd_flags = -1;
 104     gint bfd_detect_time_multiplier = -1;
 105     gint bfd_length = -1;
 106     gint bfd_my_discriminator = -1;
 107     gint bfd_your_discriminator = -1;
 108     gint bfd_desired_min_tx_interval = -1;
 109     gint bfd_required_min_rx_interval = -1;
 110     gint bfd_required_min_echo_interval = -1;
 111
 112     proto_item *ti;
 113     proto_tree *bfd_tree;
 114
 115     if (check_col(pinfo->cinfo, COL_PROTOCOL))
 116         col_set_str(pinfo->cinfo, COL_PROTOCOL, "BFD Control");
 117     if (check_col(pinfo->cinfo, COL_INFO))
 118         col_clear(pinfo->cinfo, COL_INFO);
 119
 120     bfd_version = ((tvb_get_guint8(tvb, 0) & 0xe0) >> 5);
 121     bfd_diag = (tvb_get_guint8(tvb, 0) & 0x1f);
 122     bfd_flags = tvb_get_guint8(tvb, 1);
 123     bfd_detect_time_multiplier = tvb_get_guint8(tvb, 2);
 124     bfd_length = tvb_get_guint8(tvb, 3);
 125
 126     bfd_my_discriminator = tvb_get_ntohl(tvb, 4);
 127     bfd_your_discriminator = tvb_get_ntohl(tvb, 8);
 128     bfd_desired_min_tx_interval = tvb_get_ntohl(tvb, 12);
 129     bfd_required_min_rx_interval = tvb_get_ntohl(tvb, 16);
 130     bfd_required_min_echo_interval = tvb_get_ntohl(tvb, 20);
 131
 132     if (check_col(pinfo->cinfo, COL_INFO)) {
 133         col_add_fstr(pinfo->cinfo, COL_INFO, "Diag: %s, Flags: %s",
 134                      val_to_str(bfd_diag, bfd_control_diag_values, "UNKNOWN"),
 135                      decode_enumerated_bitfield(bfd_flags,
 136                                             0xf0,
 137                                             8,
 138                                             bfd_control_flag_values,
 139                                             "%s"));
 140     }
 141
 142     if (tree) {
 143         ti = proto_tree_add_protocol_format(tree, proto_bfd, tvb, 0, -1,
 144                                             "BFD Control message");
 145
 146         bfd_tree = proto_item_add_subtree(ti, ett_bfd);
 147
 148         ti = proto_tree_add_uint(bfd_tree, hf_bfd_version, tvb, 0,
 149                                  1, bfd_version);
 150
 151         ti = proto_tree_add_uint(bfd_tree, hf_bfd_diag, tvb, 0,
 152                                  1, bfd_diag);
 153
 154         ti = proto_tree_add_text ( bfd_tree, tvb, 1, 1, "Message Flags: %s",
 155                                    decode_enumerated_bitfield(bfd_flags,
 156                                                               0xf0,
 157                                                               8,
 158                                                               bfd_control_flag_values,
 159                                                               "%s"));
 160
 161         ti = proto_tree_add_uint_format(bfd_tree, hf_bfd_detect_time_multiplier, tvb, 2,
 162                                         1, bfd_detect_time_multiplier,
 163                                         "%s: %u (= %u ms Detection time)",
 164                                         proto_registrar_get_nth(hf_bfd_detect_time_multiplier) -> name,
 165                                         bfd_detect_time_multiplier,
 166                                         bfd_detect_time_multiplier * bfd_desired_min_tx_interval/1000);
 167
 168         ti = proto_tree_add_text ( bfd_tree, tvb, 3, 1, "Message Length: %u Bytes", bfd_length );
 169
 170         ti = proto_tree_add_uint(bfd_tree, hf_bfd_my_discriminator, tvb, 4,
 171                                  4, bfd_my_discriminator);
 172
 173         ti = proto_tree_add_uint(bfd_tree, hf_bfd_your_discriminator, tvb, 8,
 174                                  4, bfd_your_discriminator);
 175
 176         ti = proto_tree_add_uint_format(bfd_tree, hf_bfd_desired_min_tx_interval, tvb, 12,
 177                                         4, bfd_desired_min_tx_interval,
 178                                         "%s: %4u ms",
 179                                         proto_registrar_get_nth(hf_bfd_desired_min_tx_interval) -> name,
 180                                         bfd_desired_min_tx_interval/1000);
 181
 182         ti = proto_tree_add_uint_format(bfd_tree, hf_bfd_required_min_rx_interval, tvb, 16,
 183                                         4, bfd_required_min_rx_interval,
 184                                         "%s: %4u ms",
 185                                         proto_registrar_get_nth(hf_bfd_required_min_rx_interval) -> name,
 186                                         bfd_required_min_rx_interval/1000);
 187
 188         ti = proto_tree_add_uint_format(bfd_tree, hf_bfd_required_min_echo_interval, tvb, 20,
 189                                         4, bfd_required_min_echo_interval,
 190                                         "%s: %4u ms",
 191                                         proto_registrar_get_nth(hf_bfd_required_min_echo_interval) -> name,
 192                                         bfd_required_min_echo_interval/1000);
 193
 194     }
 195     return;
 196 }
 197
 198 /* Register the protocol with Ethereal */
 199 void proto_register_bfd(void)
 200 {
 201
 202     /* Setup list of header fields */
 203     static hf_register_info hf[] = {
 204         { &hf_bfd_version,
 205           { "Protocol Version", "bfd.version",
 206             FT_UINT8, BASE_DEC, NULL , 0xe0,
 207             "", HFILL }
 208         },
 209         { &hf_bfd_diag,
 210           { "Diagnostic Code", "bfd.diag",
 211             FT_UINT8, BASE_HEX, VALS(bfd_control_diag_values), 0x1f,
 212             "", HFILL }
 213         },
 214         { &hf_bfd_flags,
 215           { "Message Flags", "bfd.flags",
 216             FT_UINT8, BASE_HEX, NULL, 0xf0,
 217             "", HFILL }
 218         },
 219         { &hf_bfd_detect_time_multiplier,
 220           { "Detect Time Multiplier", "bfd.detect_time_multiplier",
 221             FT_UINT8, BASE_DEC, NULL, 0x0,
 222             "", HFILL }
 223         },
 224         { &hf_bfd_my_discriminator,
 225           { "My Discriminator", "bfd.my_discriminator",
 226             FT_UINT32, BASE_HEX, NULL, 0x0,
 227             "", HFILL }
 228         },
 229         { &hf_bfd_your_discriminator,
 230           { "Your Discriminator", "bfd.your_discriminator",
 231             FT_UINT32, BASE_HEX, NULL, 0x0,
 232             "", HFILL }
 233         },
 234         { &hf_bfd_desired_min_tx_interval,
 235           { "Desired Min TX Interval", "bfd.desired_min_tx_interval",
 236             FT_UINT32, BASE_DEC, NULL, 0x0,
 237             "", HFILL }
 238         },
 239         { &hf_bfd_required_min_rx_interval,
 240           { "Required Min RX Interval", "bfd.required_min_rx_interval",
 241             FT_UINT32, BASE_DEC, NULL, 0x0,
 242             "", HFILL }
 243         },
 244         { &hf_bfd_required_min_echo_interval,
 245           { "Required Min Echo Interval", "bfd.required_min_echo_interval",
 246             FT_UINT32, BASE_DEC, NULL, 0x0,
 247             "", HFILL }
 248         },
 249     };
 250
 251     /* Setup protocol subtree array */
 252     static gint *ett[] = {
 253         &ett_bfd,
 254     };
 255
 256     /* Register the protocol name and description */
 257     proto_bfd = proto_register_protocol("Bi-directional Fault Detection Control Message",
 258                                         "BFD Control",
 259                                         "bfdcontrol");
 260
 261     /* Required function calls to register the header fields and subtrees used */
 262     proto_register_field_array(proto_bfd, hf, array_length(hf));
 263     proto_register_subtree_array(ett, array_length(ett));
 264 }
 265
 266 void
 267 proto_reg_handoff_bfd(void)
 268 {
 269     dissector_handle_t bfd_control_handle;
 270
 271     bfd_control_handle = create_dissector_handle(dissect_bfd_control, proto_bfd);
 272     dissector_add("udp.port", UDP_PORT_BFD_CONTROL, bfd_control_handle);
 273 }