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 1.2 2000/01/07 22:05:42 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
  45 static gint proto_vrrp = -1;
  46 static gint ett_vrrp = -1;
  47 static gint ett_vrrp_ver_type = -1;
  48
  49 static gint hf_vrrp_ver_type = -1;
  50 static gint hf_vrrp_version = -1;
  51 static gint hf_vrrp_type = -1;
  52
  53 struct vrrp_header {
  54 #define VRRP_VERSION_MASK 0xf0
  55 #define VRRP_TYPE_MASK 0x0f
  56         guint8  ver_type;
  57         guint8  vrouter_id;
  58         guint8  priority;
  59         guint8  count_ip_addrs;
  60         guint8  auth_type;
  61         guint8  adver_int;
  62         guint16 checksum;
  63         /* One or more IP addresses */
  64         /* 8 octets of authentication data */
  65 #define VRRP_AUTH_DATA_LEN 8
  66 };
  67
  68
  69 #define VRRP_TYPE_ADVERTISEMENT 1
  70 static const value_string vrrp_type_vals[] = {
  71         {VRRP_TYPE_ADVERTISEMENT, "Advertisement"}
  72 };
  73
  74 #define VRRP_AUTH_TYPE_NONE 0
  75 #define VRRP_AUTH_TYPE_SIMPLE_TEXT 1
  76 #define VRRP_AUTH_TYPE_IP_AUTH_HDR 2
  77 static const value_string vrrp_auth_vals[] = {
  78         {VRRP_AUTH_TYPE_NONE,        "No Authentication"},
  79         {VRRP_AUTH_TYPE_SIMPLE_TEXT, "Simple Text Authentication"},
  80         {VRRP_AUTH_TYPE_IP_AUTH_HDR, "IP Authentication Header"}
  81 };
  82
  83 #define VRRP_PRIORITY_MASTER_STOPPING 0
  84 /* Values between 1 and 254 inclusive are for backup VRRP routers */
  85 #define VRRP_PRIORITY_DEFAULT 100
  86 #define VRRP_PRIORITY_OWNER 255
  87 static const value_string vrrp_prio_vals[] = {
  88         {VRRP_PRIORITY_MASTER_STOPPING,  "Current Master has stopped participating in VRRP"},
  89         {VRRP_PRIORITY_DEFAULT,          "Default priority for a backup VRRP router"},
  90         {VRRP_PRIORITY_OWNER,            "This VRRP router owns the virtual router's IP address(es)"}
  91 };
  92
  93
  94 void dissect_vrrp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
  95 {
  96         struct vrrp_header vrh;
  97         gboolean short_hdr = FALSE;
  98         gboolean short_packet = FALSE;
  99         guint calculated_len = -1; /* initialize to silence false warning from gcc */
 100
 101         if (sizeof(struct vrrp_header) > END_OF_FRAME)
 102                 short_hdr = short_packet = TRUE;
 103         else {
 104                 memcpy(&vrh, pd + offset, sizeof(struct vrrp_header));
 105                 calculated_len = sizeof(struct vrrp_header) + vrh.count_ip_addrs*4 + VRRP_AUTH_DATA_LEN;
 106                 if (calculated_len > END_OF_FRAME)
 107                         short_packet = TRUE;
 108         }
 109
 110         if (check_col(fd, COL_PROTOCOL))
 111                 col_add_str(fd, COL_PROTOCOL, "VRRP");
 112
 113         if (check_col(fd, COL_INFO)) {
 114                 if (short_hdr)
 115                         col_add_fstr(fd, COL_INFO, "Short packet header, length %u", END_OF_FRAME);
 116                 else if (short_packet)
 117                         col_add_fstr(fd, COL_INFO, "Packet length mismatch, calculated %u, real %u",
 118                                      calculated_len, END_OF_FRAME);
 119                 else
 120                         col_add_fstr(fd, COL_INFO, "%s (v%u)", "Announcement", hi_nibble(vrh.ver_type));
 121         }
 122
 123         if (tree) {
 124                 proto_item *ti, *tv;
 125                 proto_tree *vrrp_tree, *ver_type_tree;
 126                 guint8 ip_count, auth_len, auth_buf[VRRP_AUTH_DATA_LEN+1];
 127
 128                 if (short_hdr) {
 129                         dissect_data(pd, offset, fd, tree);
 130                         return;
 131                 }
 132
 133                 ti = proto_tree_add_item(tree, proto_vrrp, offset, END_OF_FRAME, NULL);
 134                 vrrp_tree = proto_item_add_subtree(ti, ett_vrrp);
 135
 136                 tv = proto_tree_add_item_format(vrrp_tree, hf_vrrp_ver_type, offset, 1,
 137                                                 vrh.ver_type, "Version %u, Packet type %u (%s)",
 138                                                 hi_nibble(vrh.ver_type), lo_nibble(vrh.ver_type),
 139                                                 val_to_str(lo_nibble(vrh.ver_type), vrrp_type_vals, "Unknown"));
 140                 ver_type_tree = proto_item_add_subtree(tv, ett_vrrp_ver_type);
 141                 proto_tree_add_item(ver_type_tree, hf_vrrp_version, offset, 1, vrh.ver_type);
 142                 proto_tree_add_item(ver_type_tree, hf_vrrp_type, offset, 1, vrh.ver_type);
 143                 offset++;
 144
 145                 proto_tree_add_text(vrrp_tree, offset++, 1, "Virtual Router ID: %u", vrh.vrouter_id);
 146                 proto_tree_add_text(vrrp_tree, offset++, 1, "Priority: %u (%s)", vrh.priority,
 147                                     val_to_str(vrh.priority, vrrp_prio_vals, "Non-default backup priority"));
 148                 proto_tree_add_text(vrrp_tree, offset++, 1, "Count IP Addrs: %u", vrh.count_ip_addrs);
 149                 proto_tree_add_text(vrrp_tree, offset++, 1, "Authentication Type: %u (%s)", vrh.auth_type,
 150                                     val_to_str(vrh.auth_type, vrrp_auth_vals, "Unknown"));
 151                 proto_tree_add_text(vrrp_tree, offset++, 1, "Advertisement Interval: %u second%s",
 152                                     vrh.adver_int, plurality(vrh.adver_int, "", "s"));
 153                 proto_tree_add_text(vrrp_tree, offset, 2, "Checksum: 0x%x", htons(vrh.checksum));
 154                 offset+=2;
 155
 156                 if (short_packet) {
 157                         dissect_data(pd, offset, fd, vrrp_tree);
 158                         return;
 159                 }
 160
 161                 ip_count = vrh.count_ip_addrs;
 162                 while (ip_count > 0) {
 163                         proto_tree_add_text(vrrp_tree, offset, 4, "Virtual Router IP address: %s",
 164                                             ip_to_str(pd+offset));
 165                         offset+=4;
 166                         ip_count--;
 167                 }
 168
 169                 if (vrh.auth_type != VRRP_AUTH_TYPE_SIMPLE_TEXT)
 170                         return; /* Contents of the authentication data is undefined */
 171
 172                 strncpy(auth_buf, pd+offset, VRRP_AUTH_DATA_LEN);
 173                 auth_buf[VRRP_AUTH_DATA_LEN] = '\0';
 174                 auth_len = strlen(auth_buf);
 175                 if (auth_len > 0)
 176                         proto_tree_add_text(vrrp_tree, offset, auth_len, "Authentication string: `%s'", auth_buf);
 177                 offset+=8;
 178
 179         }
 180
 181         return;
 182 }
 183
 184 void proto_register_vrrp(void)
 185 {
 186         static hf_register_info hf[] = {
 187                 { &hf_vrrp_ver_type,
 188                   {"VRRP message version and type", "vrrp.typever",
 189                    FT_UINT8, BASE_DEC, NULL, 0x0,
 190                    "VRRP version and type"}},
 191
 192                 { &hf_vrrp_version,
 193                   {"VRRP protocol version", "vrrp.version",
 194                    FT_UINT8, BASE_DEC, NULL, VRRP_VERSION_MASK,
 195                    "VRRP version"}},
 196
 197                 { &hf_vrrp_type,
 198                   {"VRRP packet type", "vrrp.type",
 199                    FT_UINT8, BASE_DEC, VALS(vrrp_type_vals), VRRP_TYPE_MASK,
 200                    "VRRP type"}}
 201         };
 202
 203         static gint *ett[] = {
 204                 &ett_vrrp,
 205                 &ett_vrrp_ver_type
 206         };
 207
 208         proto_vrrp = proto_register_protocol("Virtual Router Redundancy Protocol", "vrrp");
 209         proto_register_field_array(proto_vrrp, hf, array_length(hf));
 210         proto_register_subtree_array(ett, array_length(ett));
 211
 212         return;
 213 }