packet-vrrp.c

   1 /* packet-vrrp.c
   2  * Routines for the Virtual Router Redundancy Protocol (VRRP)
   3  * RFC2338
   4  *
   5  * Heikki Vatiainen <hessu@cs.tut.fi>
   6  *
   7  * $Id: packet-vrrp.c,v 1.12 2001/01/06 05:43:13 guy Exp $
   8  *
   9  * Ethereal - Network traffic analyzer
  10  * By Gerald Combs <gerald@zing.org>
  11  * Copyright 1998 Gerald Combs
  12  *
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  27  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #ifdef HAVE_SYS_TYPES_H
  34 # include <sys/types.h>
  35 #endif
  36
  37 #ifdef HAVE_NETINET_IN_H
  38 #include <netinet/in.h>
  39 #endif
  40
  41 #include <string.h>
  42 #include <glib.h>
  43 #include "packet.h"
  44 #include "packet-ip.h"
  45 #include "in_cksum.h"
  46
  47 static gint proto_vrrp = -1;
  48 static gint ett_vrrp = -1;
  49 static gint ett_vrrp_ver_type = -1;
  50
  51 static gint hf_vrrp_ver_type = -1;
  52 static gint hf_vrrp_version = -1;
  53 static gint hf_vrrp_type = -1;
  54
  55 #define VRRP_VERSION_MASK 0xf0
  56 #define VRRP_TYPE_MASK 0x0f
  57 #define VRRP_AUTH_DATA_LEN 8
  58
  59 #define VRRP_TYPE_ADVERTISEMENT 1
  60 static const value_string vrrp_type_vals[] = {
  61         {VRRP_TYPE_ADVERTISEMENT, "Advertisement"},
  62         {0, NULL}
  63 };
  64
  65 #define VRRP_AUTH_TYPE_NONE 0
  66 #define VRRP_AUTH_TYPE_SIMPLE_TEXT 1
  67 #define VRRP_AUTH_TYPE_IP_AUTH_HDR 2
  68 static const value_string vrrp_auth_vals[] = {
  69         {VRRP_AUTH_TYPE_NONE,        "No Authentication"},
  70         {VRRP_AUTH_TYPE_SIMPLE_TEXT, "Simple Text Authentication"},
  71         {VRRP_AUTH_TYPE_IP_AUTH_HDR, "IP Authentication Header"},
  72         {0,                          NULL}
  73 };
  74
  75 #define VRRP_PRIORITY_MASTER_STOPPING 0
  76 /* Values between 1 and 254 inclusive are for backup VRRP routers */
  77 #define VRRP_PRIORITY_DEFAULT 100
  78 #define VRRP_PRIORITY_OWNER 255
  79 static const value_string vrrp_prio_vals[] = {
  80         {VRRP_PRIORITY_MASTER_STOPPING,  "Current Master has stopped participating in VRRP"},
  81         {VRRP_PRIORITY_DEFAULT,          "Default priority for a backup VRRP router"},
  82         {VRRP_PRIORITY_OWNER,            "This VRRP router owns the virtual router's IP address(es)"},
  83         {0,                              NULL }
  84 };
  85
  86
  87 static void
  88 dissect_vrrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  89 {
  90         int offset = 0;
  91         gint vrrp_len;
  92         guint8  ver_type;
  93         vec_t cksum_vec[1];
  94
  95         CHECK_DISPLAY_AS_DATA(proto_vrrp, tvb, pinfo, tree);
  96
  97         pinfo->current_proto = "VRRP";
  98
  99         if (check_col(pinfo->fd, COL_PROTOCOL))
 100                 col_set_str(pinfo->fd, COL_PROTOCOL, "VRRP");
 101         if (check_col(pinfo->fd, COL_INFO))
 102                 col_clear(pinfo->fd, COL_INFO);
 103
 104         ver_type = tvb_get_guint8(tvb, 0);
 105         if (check_col(pinfo->fd, COL_INFO)) {
 106                 col_add_fstr(pinfo->fd, COL_INFO, "%s (v%u)",
 107                              "Announcement", hi_nibble(ver_type));
 108         }
 109
 110         if (tree) {
 111                 proto_item *ti, *tv;
 112                 proto_tree *vrrp_tree, *ver_type_tree;
 113                 guint8 priority, ip_count, auth_type, adver_int;
 114                 guint16 cksum, computed_cksum;
 115                 guint8 auth_buf[VRRP_AUTH_DATA_LEN+1];
 116
 117                 ti = proto_tree_add_item(tree, proto_vrrp, tvb, 0,
 118                                          tvb_length(tvb), FALSE);
 119                 vrrp_tree = proto_item_add_subtree(ti, ett_vrrp);
 120
 121                 tv = proto_tree_add_uint_format(vrrp_tree, hf_vrrp_ver_type,
 122                                                 tvb, offset, 1, ver_type,
 123                                                 "Version %u, Packet type %u (%s)",
 124                                                 hi_nibble(ver_type), lo_nibble(ver_type),
 125                                                 val_to_str(lo_nibble(ver_type), vrrp_type_vals, "Unknown"));
 126                 ver_type_tree = proto_item_add_subtree(tv, ett_vrrp_ver_type);
 127                 proto_tree_add_uint(ver_type_tree, hf_vrrp_version, tvb,
 128                                     offset, 1, ver_type);
 129                 proto_tree_add_uint(ver_type_tree, hf_vrrp_type, tvb, offset, 1,
 130                                     ver_type);
 131                 offset++;
 132
 133                 proto_tree_add_text(vrrp_tree, tvb, offset, 1,
 134                                     "Virtual Router ID: %u",
 135                                     tvb_get_guint8(tvb, offset));
 136                 offset++;
 137
 138                 priority = tvb_get_guint8(tvb, offset);
 139                 proto_tree_add_text(vrrp_tree, tvb, offset, 1, "Priority: %u (%s)",
 140                                     priority,
 141                                     val_to_str(priority, vrrp_prio_vals, "Non-default backup priority"));
 142                 offset++;
 143
 144                 ip_count = tvb_get_guint8(tvb, offset);
 145                 proto_tree_add_text(vrrp_tree, tvb, offset, 1,
 146                                     "Count IP Addrs: %u", ip_count);
 147                 offset++;
 148
 149                 auth_type = tvb_get_guint8(tvb, offset);
 150                 proto_tree_add_text(vrrp_tree, tvb, offset, 1,
 151                                     "Authentication Type: %u (%s)", auth_type,
 152                                     val_to_str(auth_type, vrrp_auth_vals, "Unknown"));
 153                 offset++;
 154
 155                 adver_int = tvb_get_guint8(tvb, offset);
 156                 proto_tree_add_text(vrrp_tree, tvb, offset, 1,
 157                                     "Advertisement Interval: %u second%s",
 158                                     adver_int, plurality(adver_int, "", "s"));
 159                 offset++;
 160
 161                 cksum = tvb_get_ntohs(tvb, offset);
 162                 vrrp_len = tvb_reported_length(tvb);
 163                 if (!pinfo->fragmented && tvb_length(tvb) >= vrrp_len) {
 164                         /* The packet isn't part of a fragmented datagram
 165                            and isn't truncated, so we can checksum it. */
 166                         cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, vrrp_len);
 167                         cksum_vec[0].len = vrrp_len;
 168                         computed_cksum = in_cksum(&cksum_vec[0], 1);
 169                         if (computed_cksum == 0) {
 170                                 proto_tree_add_text(vrrp_tree, tvb, offset, 2,
 171                                                     "Checksum: 0x%04x (correct)",
 172                                                     cksum);
 173                         } else {
 174                                 proto_tree_add_text(vrrp_tree, tvb, offset, 2,
 175                                                     "Checksum: 0x%04x (incorrect, should be 0x%04x)",
 176                                                     cksum,
 177                                                     in_cksum_shouldbe(cksum, computed_cksum));
 178                         }
 179                 } else {
 180                         proto_tree_add_text(vrrp_tree, tvb, offset, 2,
 181                                             "Checksum: 0x%04x", cksum);
 182                 }
 183                 offset+=2;
 184
 185                 while (ip_count > 0) {
 186                         proto_tree_add_text(vrrp_tree, tvb, offset, 4,
 187                                             "Virtual Router IP address: %s",
 188                                             ip_to_str(tvb_get_ptr(tvb, offset, 4)));
 189                         offset+=4;
 190                         ip_count--;
 191                 }
 192
 193                 if (auth_type != VRRP_AUTH_TYPE_SIMPLE_TEXT)
 194                         return; /* Contents of the authentication data is undefined */
 195
 196                 tvb_get_nstringz0(tvb, offset, VRRP_AUTH_DATA_LEN, auth_buf);
 197                 if (auth_buf[0] != '\0')
 198                         proto_tree_add_text(vrrp_tree, tvb, offset,
 199                                             VRRP_AUTH_DATA_LEN,
 200                                             "Authentication string: `%s'",
 201                                             auth_buf);
 202                 offset+=8;
 203         }
 204 }
 205
 206 void proto_register_vrrp(void)
 207 {
 208         static hf_register_info hf[] = {
 209                 { &hf_vrrp_ver_type,
 210                   {"VRRP message version and type", "vrrp.typever",
 211                    FT_UINT8, BASE_DEC, NULL, 0x0,
 212                    "VRRP version and type"}},
 213
 214                 { &hf_vrrp_version,
 215                   {"VRRP protocol version", "vrrp.version",
 216                    FT_UINT8, BASE_DEC, NULL, VRRP_VERSION_MASK,
 217                    "VRRP version"}},
 218
 219                 { &hf_vrrp_type,
 220                   {"VRRP packet type", "vrrp.type",
 221                    FT_UINT8, BASE_DEC, VALS(vrrp_type_vals), VRRP_TYPE_MASK,
 222                    "VRRP type"}}
 223         };
 224
 225         static gint *ett[] = {
 226                 &ett_vrrp,
 227                 &ett_vrrp_ver_type
 228         };
 229
 230         proto_vrrp = proto_register_protocol("Virtual Router Redundancy Protocol",
 231             "VRRP", "vrrp");
 232         proto_register_field_array(proto_vrrp, hf, array_length(hf));
 233         proto_register_subtree_array(ett, array_length(ett));
 234
 235         return;
 236 }
 237
 238 void
 239 proto_reg_handoff_vrrp(void)
 240 {
 241         dissector_add("ip.proto", IP_PROTO_VRRP, dissect_vrrp);
 242 }