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 1.6 2000/05/31 05:07:53 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
  46 static gint proto_vrrp = -1;
  47 static gint ett_vrrp = -1;
  48 static gint ett_vrrp_ver_type = -1;
  49
  50 static gint hf_vrrp_ver_type = -1;
  51 static gint hf_vrrp_version = -1;
  52 static gint hf_vrrp_type = -1;
  53
  54 struct vrrp_header {
  55 #define VRRP_VERSION_MASK 0xf0
  56 #define VRRP_TYPE_MASK 0x0f
  57         guint8  ver_type;
  58         guint8  vrouter_id;
  59         guint8  priority;
  60         guint8  count_ip_addrs;
  61         guint8  auth_type;
  62         guint8  adver_int;
  63         guint16 checksum;
  64         /* One or more IP addresses */
  65         /* 8 octets of authentication data */
  66 #define VRRP_AUTH_DATA_LEN 8
  67 };
  68
  69
  70 #define VRRP_TYPE_ADVERTISEMENT 1
  71 static const value_string vrrp_type_vals[] = {
  72         {VRRP_TYPE_ADVERTISEMENT, "Advertisement"}
  73 };
  74
  75 #define VRRP_AUTH_TYPE_NONE 0
  76 #define VRRP_AUTH_TYPE_SIMPLE_TEXT 1
  77 #define VRRP_AUTH_TYPE_IP_AUTH_HDR 2
  78 static const value_string vrrp_auth_vals[] = {
  79         {VRRP_AUTH_TYPE_NONE,        "No Authentication"},
  80         {VRRP_AUTH_TYPE_SIMPLE_TEXT, "Simple Text Authentication"},
  81         {VRRP_AUTH_TYPE_IP_AUTH_HDR, "IP Authentication Header"}
  82 };
  83
  84 #define VRRP_PRIORITY_MASTER_STOPPING 0
  85 /* Values between 1 and 254 inclusive are for backup VRRP routers */
  86 #define VRRP_PRIORITY_DEFAULT 100
  87 #define VRRP_PRIORITY_OWNER 255
  88 static const value_string vrrp_prio_vals[] = {
  89         {VRRP_PRIORITY_MASTER_STOPPING,  "Current Master has stopped participating in VRRP"},
  90         {VRRP_PRIORITY_DEFAULT,          "Default priority for a backup VRRP router"},
  91         {VRRP_PRIORITY_OWNER,            "This VRRP router owns the virtual router's IP address(es)"}
  92 };
  93
  94
  95 static void
  96 dissect_vrrp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
  97 {
  98         struct vrrp_header vrh;
  99         gboolean short_hdr = FALSE;
 100         gboolean short_packet = FALSE;
 101         guint calculated_len = -1; /* initialize to silence false warning from gcc */
 102
 103         if (sizeof(struct vrrp_header) > END_OF_FRAME)
 104                 short_hdr = short_packet = TRUE;
 105         else {
 106                 memcpy(&vrh, pd + offset, sizeof(struct vrrp_header));
 107                 calculated_len = sizeof(struct vrrp_header) + vrh.count_ip_addrs*4 + VRRP_AUTH_DATA_LEN;
 108                 if (calculated_len > END_OF_FRAME)
 109                         short_packet = TRUE;
 110         }
 111
 112         if (check_col(fd, COL_PROTOCOL))
 113                 col_add_str(fd, COL_PROTOCOL, "VRRP");
 114
 115         if (check_col(fd, COL_INFO)) {
 116                 if (short_hdr)
 117                         col_add_fstr(fd, COL_INFO, "Short packet header, length %u", END_OF_FRAME);
 118                 else if (short_packet)
 119                         col_add_fstr(fd, COL_INFO, "Packet length mismatch, calculated %u, real %u",
 120                                      calculated_len, END_OF_FRAME);
 121                 else
 122                         col_add_fstr(fd, COL_INFO, "%s (v%u)", "Announcement", hi_nibble(vrh.ver_type));
 123         }
 124
 125         if (tree) {
 126                 proto_item *ti, *tv;
 127                 proto_tree *vrrp_tree, *ver_type_tree;
 128                 guint8 ip_count, auth_len, auth_buf[VRRP_AUTH_DATA_LEN+1];
 129
 130                 if (short_hdr) {
 131                         dissect_data(pd, offset, fd, tree);
 132                         return;
 133                 }
 134
 135                 ti = proto_tree_add_item(tree, proto_vrrp, NullTVB, offset, END_OF_FRAME, FALSE);
 136                 vrrp_tree = proto_item_add_subtree(ti, ett_vrrp);
 137
 138                 tv = proto_tree_add_uint_format(vrrp_tree, hf_vrrp_ver_type, NullTVB, offset, 1,
 139                                                 vrh.ver_type, "Version %u, Packet type %u (%s)",
 140                                                 hi_nibble(vrh.ver_type), lo_nibble(vrh.ver_type),
 141                                                 val_to_str(lo_nibble(vrh.ver_type), vrrp_type_vals, "Unknown"));
 142                 ver_type_tree = proto_item_add_subtree(tv, ett_vrrp_ver_type);
 143                 proto_tree_add_uint(ver_type_tree, hf_vrrp_version, NullTVB, offset, 1, vrh.ver_type);
 144                 proto_tree_add_uint(ver_type_tree, hf_vrrp_type, NullTVB, offset, 1, vrh.ver_type);
 145                 offset++;
 146
 147                 proto_tree_add_text(vrrp_tree, NullTVB, offset++, 1, "Virtual Router ID: %u", vrh.vrouter_id);
 148                 proto_tree_add_text(vrrp_tree, NullTVB, offset++, 1, "Priority: %u (%s)", vrh.priority,
 149                                     val_to_str(vrh.priority, vrrp_prio_vals, "Non-default backup priority"));
 150                 proto_tree_add_text(vrrp_tree, NullTVB, offset++, 1, "Count IP Addrs: %u", vrh.count_ip_addrs);
 151                 proto_tree_add_text(vrrp_tree, NullTVB, offset++, 1, "Authentication Type: %u (%s)", vrh.auth_type,
 152                                     val_to_str(vrh.auth_type, vrrp_auth_vals, "Unknown"));
 153                 proto_tree_add_text(vrrp_tree, NullTVB, offset++, 1, "Advertisement Interval: %u second%s",
 154                                     vrh.adver_int, plurality(vrh.adver_int, "", "s"));
 155                 proto_tree_add_text(vrrp_tree, NullTVB, offset, 2, "Checksum: 0x%x", htons(vrh.checksum));
 156                 offset+=2;
 157
 158                 if (short_packet) {
 159                         dissect_data(pd, offset, fd, vrrp_tree);
 160                         return;
 161                 }
 162
 163                 ip_count = vrh.count_ip_addrs;
 164                 while (ip_count > 0) {
 165                         proto_tree_add_text(vrrp_tree, NullTVB, offset, 4, "Virtual Router IP address: %s",
 166                                             ip_to_str(pd+offset));
 167                         offset+=4;
 168                         ip_count--;
 169                 }
 170
 171                 if (vrh.auth_type != VRRP_AUTH_TYPE_SIMPLE_TEXT)
 172                         return; /* Contents of the authentication data is undefined */
 173
 174                 strncpy(auth_buf, pd+offset, VRRP_AUTH_DATA_LEN);
 175                 auth_buf[VRRP_AUTH_DATA_LEN] = '\0';
 176                 auth_len = strlen(auth_buf);
 177                 if (auth_len > 0)
 178                         proto_tree_add_text(vrrp_tree, NullTVB, offset, auth_len, "Authentication string: `%s'", auth_buf);
 179                 offset+=8;
 180
 181         }
 182
 183         return;
 184 }
 185
 186 void proto_register_vrrp(void)
 187 {
 188         static hf_register_info hf[] = {
 189                 { &hf_vrrp_ver_type,
 190                   {"VRRP message version and type", "vrrp.typever",
 191                    FT_UINT8, BASE_DEC, NULL, 0x0,
 192                    "VRRP version and type"}},
 193
 194                 { &hf_vrrp_version,
 195                   {"VRRP protocol version", "vrrp.version",
 196                    FT_UINT8, BASE_DEC, NULL, VRRP_VERSION_MASK,
 197                    "VRRP version"}},
 198
 199                 { &hf_vrrp_type,
 200                   {"VRRP packet type", "vrrp.type",
 201                    FT_UINT8, BASE_DEC, VALS(vrrp_type_vals), VRRP_TYPE_MASK,
 202                    "VRRP type"}}
 203         };
 204
 205         static gint *ett[] = {
 206                 &ett_vrrp,
 207                 &ett_vrrp_ver_type
 208         };
 209
 210         proto_vrrp = proto_register_protocol("Virtual Router Redundancy Protocol", "vrrp");
 211         proto_register_field_array(proto_vrrp, hf, array_length(hf));
 212         proto_register_subtree_array(ett, array_length(ett));
 213
 214         return;
 215 }
 216
 217 void
 218 proto_reg_handoff_vrrp(void)
 219 {
 220         dissector_add("ip.proto", IP_PROTO_VRRP, dissect_vrrp);
 221 }