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 1.17 2001/07/12 19:43:59 guy Exp $
   8  *
   9  * Ethereal - Network traffic analyzer
  10  * By Gerald Combs <gerald@ethereal.com>
  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 "ipproto.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 static gint hf_vrrp_virt_rtr_id = -1;
  55 static gint hf_vrrp_prio = -1;
  56 static gint hf_vrrp_count_ip = -1;
  57 static gint hf_vrrp_auth_type = -1;
  58 static gint hf_vrrp_adver_int = -1;
  59 static gint hf_vrrp_ip = -1;
  60
  61 #define VRRP_VERSION_MASK 0xf0
  62 #define VRRP_TYPE_MASK 0x0f
  63 #define VRRP_AUTH_DATA_LEN 8
  64
  65 #define VRRP_TYPE_ADVERTISEMENT 1
  66 static const value_string vrrp_type_vals[] = {
  67         {VRRP_TYPE_ADVERTISEMENT, "Advertisement"},
  68         {0, NULL}
  69 };
  70
  71 #define VRRP_AUTH_TYPE_NONE 0
  72 #define VRRP_AUTH_TYPE_SIMPLE_TEXT 1
  73 #define VRRP_AUTH_TYPE_IP_AUTH_HDR 2
  74 static const value_string vrrp_auth_vals[] = {
  75         {VRRP_AUTH_TYPE_NONE,        "No Authentication"},
  76         {VRRP_AUTH_TYPE_SIMPLE_TEXT, "Simple Text Authentication"},
  77         {VRRP_AUTH_TYPE_IP_AUTH_HDR, "IP Authentication Header"},
  78         {0,                          NULL}
  79 };
  80
  81 #define VRRP_PRIORITY_MASTER_STOPPING 0
  82 /* Values between 1 and 254 inclusive are for backup VRRP routers */
  83 #define VRRP_PRIORITY_DEFAULT 100
  84 #define VRRP_PRIORITY_OWNER 255
  85 static const value_string vrrp_prio_vals[] = {
  86         {VRRP_PRIORITY_MASTER_STOPPING,  "Current Master has stopped participating in VRRP"},
  87         {VRRP_PRIORITY_DEFAULT,          "Default priority for a backup VRRP router"},
  88         {VRRP_PRIORITY_OWNER,            "This VRRP router owns the virtual router's IP address(es)"},
  89         {0,                              NULL }
  90 };
  91
  92
  93 static void
  94 dissect_vrrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  95 {
  96         int offset = 0;
  97         gint vrrp_len;
  98         guint8  ver_type;
  99         vec_t cksum_vec[1];
 100
 101         if (check_col(pinfo->fd, COL_PROTOCOL))
 102                 col_set_str(pinfo->fd, COL_PROTOCOL, "VRRP");
 103         if (check_col(pinfo->fd, COL_INFO))
 104                 col_clear(pinfo->fd, COL_INFO);
 105
 106         ver_type = tvb_get_guint8(tvb, 0);
 107         if (check_col(pinfo->fd, COL_INFO)) {
 108                 col_add_fstr(pinfo->fd, COL_INFO, "%s (v%u)",
 109                              "Announcement", hi_nibble(ver_type));
 110         }
 111
 112         if (tree) {
 113                 proto_item *ti, *tv;
 114                 proto_tree *vrrp_tree, *ver_type_tree;
 115                 guint8 priority, ip_count, auth_type;
 116                 guint16 cksum, computed_cksum;
 117                 guint8 auth_buf[VRRP_AUTH_DATA_LEN+1];
 118
 119                 ti = proto_tree_add_item(tree, proto_vrrp, tvb, 0,
 120                                          tvb_length(tvb), FALSE);
 121                 vrrp_tree = proto_item_add_subtree(ti, ett_vrrp);
 122
 123                 tv = proto_tree_add_uint_format(vrrp_tree, hf_vrrp_ver_type,
 124                                                 tvb, offset, 1, ver_type,
 125                                                 "Version %u, Packet type %u (%s)",
 126                                                 hi_nibble(ver_type), lo_nibble(ver_type),
 127                                                 val_to_str(lo_nibble(ver_type), vrrp_type_vals, "Unknown"));
 128                 ver_type_tree = proto_item_add_subtree(tv, ett_vrrp_ver_type);
 129                 proto_tree_add_uint(ver_type_tree, hf_vrrp_version, tvb,
 130                                     offset, 1, ver_type);
 131                 proto_tree_add_uint(ver_type_tree, hf_vrrp_type, tvb, offset, 1,
 132                                     ver_type);
 133                 offset++;
 134
 135                 proto_tree_add_item(vrrp_tree, hf_vrrp_virt_rtr_id, tvb, offset, 1, FALSE);
 136                 offset++;
 137
 138                 priority = tvb_get_guint8(tvb, offset);
 139                 proto_tree_add_uint_format(vrrp_tree, hf_vrrp_prio, tvb, offset, 1, priority, "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_uint(vrrp_tree, hf_vrrp_count_ip, tvb, offset, 1, ip_count);
 146                 offset++;
 147
 148                 auth_type = tvb_get_guint8(tvb, offset);
 149                 proto_tree_add_item(vrrp_tree, hf_vrrp_auth_type, tvb, offset, 1, FALSE);
 150                 offset++;
 151
 152                 proto_tree_add_item(vrrp_tree, hf_vrrp_adver_int, tvb, offset, 1, FALSE);
 153                 offset++;
 154
 155                 cksum = tvb_get_ntohs(tvb, offset);
 156                 vrrp_len = (gint)tvb_reported_length(tvb);
 157                 if (!pinfo->fragmented && (gint)tvb_length(tvb) >= vrrp_len) {
 158                         /* The packet isn't part of a fragmented datagram
 159                            and isn't truncated, so we can checksum it. */
 160                         cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, vrrp_len);
 161                         cksum_vec[0].len = vrrp_len;
 162                         computed_cksum = in_cksum(&cksum_vec[0], 1);
 163                         if (computed_cksum == 0) {
 164                                 proto_tree_add_text(vrrp_tree, tvb, offset, 2,
 165                                                     "Checksum: 0x%04x (correct)",
 166                                                     cksum);
 167                         } else {
 168                                 proto_tree_add_text(vrrp_tree, tvb, offset, 2,
 169                                                     "Checksum: 0x%04x (incorrect, should be 0x%04x)",
 170                                                     cksum,
 171                                                     in_cksum_shouldbe(cksum, computed_cksum));
 172                         }
 173                 } else {
 174                         proto_tree_add_text(vrrp_tree, tvb, offset, 2,
 175                                             "Checksum: 0x%04x", cksum);
 176                 }
 177                 offset+=2;
 178
 179                 while (ip_count > 0) {
 180                         proto_tree_add_item(vrrp_tree, hf_vrrp_ip, tvb, offset, 4, FALSE);
 181                         offset+=4;
 182                         ip_count--;
 183                 }
 184
 185                 if (auth_type != VRRP_AUTH_TYPE_SIMPLE_TEXT)
 186                         return; /* Contents of the authentication data is undefined */
 187
 188                 tvb_get_nstringz0(tvb, offset, VRRP_AUTH_DATA_LEN, auth_buf);
 189                 if (auth_buf[0] != '\0')
 190                         proto_tree_add_text(vrrp_tree, tvb, offset,
 191                                             VRRP_AUTH_DATA_LEN,
 192                                             "Authentication string: `%s'",
 193                                             auth_buf);
 194                 offset+=8;
 195         }
 196 }
 197
 198 void proto_register_vrrp(void)
 199 {
 200         static hf_register_info hf[] = {
 201                 { &hf_vrrp_ver_type,
 202                   {"VRRP message version and type", "vrrp.typever",
 203                    FT_UINT8, BASE_DEC, NULL, 0x0,
 204                    "VRRP version and type", HFILL }},
 205
 206                 { &hf_vrrp_version,
 207                   {"VRRP protocol version", "vrrp.version",
 208                    FT_UINT8, BASE_DEC, NULL, VRRP_VERSION_MASK,
 209                    "VRRP version", HFILL }},
 210
 211                 { &hf_vrrp_type,
 212                   {"VRRP packet type", "vrrp.type",
 213                    FT_UINT8, BASE_DEC, VALS(vrrp_type_vals), VRRP_TYPE_MASK,
 214                    "VRRP type", HFILL }},
 215
 216                 { &hf_vrrp_virt_rtr_id,
 217                   {"Virtual Rtr ID", "vrrp.virt_rtr_id",
 218                    FT_UINT8, BASE_DEC, NULL, 0x0,
 219                    "Virtual router this packet is reporting status for", HFILL }},
 220
 221                 { &hf_vrrp_prio,
 222                   {"Priority", "vrrp.prio",
 223                    FT_UINT8, BASE_DEC, NULL, 0x0,
 224                    "Sending VRRP router's priority for the virtual router", HFILL }},
 225
 226                 { &hf_vrrp_count_ip,
 227                   {"Count IP Addrs", "vrrp.count_ip_addrs",
 228                    FT_UINT8, BASE_DEC, NULL, 0x0,
 229                    "The number of IP addresses contained in this VRRP advertisement", HFILL }},
 230
 231                 { &hf_vrrp_auth_type,
 232                   {"Auth Type", "vrrp.auth_type",
 233                    FT_UINT8, BASE_DEC, VALS(vrrp_auth_vals), 0x0,
 234                    "The authentication method being utilized", HFILL }},
 235
 236                 { &hf_vrrp_adver_int,
 237                   {"Adver Int", "vrrp.adver_int",
 238                    FT_UINT8, BASE_DEC, NULL, 0x0,
 239                    "Time interval (in seconds) between ADVERTISEMENTS", HFILL }},
 240
 241                 { &hf_vrrp_ip,
 242                   {"IP Address", "vrrp.ip_addr",
 243                    FT_IPv4, 0, NULL, 0x0,
 244                    "IP address associated with the virtual router", HFILL }},
 245
 246         };
 247
 248         static gint *ett[] = {
 249                 &ett_vrrp,
 250                 &ett_vrrp_ver_type
 251         };
 252
 253         proto_vrrp = proto_register_protocol("Virtual Router Redundancy Protocol",
 254             "VRRP", "vrrp");
 255         proto_register_field_array(proto_vrrp, hf, array_length(hf));
 256         proto_register_subtree_array(ett, array_length(ett));
 257
 258         return;
 259 }
 260
 261 void
 262 proto_reg_handoff_vrrp(void)
 263 {
 264         dissector_add("ip.proto", IP_PROTO_VRRP, dissect_vrrp, proto_vrrp);
 265 }