2 * Routines for the Cisco Hot Standby Router Protocol (HSRP)
5 * Heikki Vatiainen <hessu@cs.tut.fi>
7 * $Id: packet-hsrp.c,v 1.4 2000/05/11 08:15:10 gram Exp $
9 * Ethereal - Network traffic analyzer
10 * By Gerald Combs <gerald@zing.org>
11 * Copyright 1998 Gerald Combs
13 * Copied from packet-vrrp.c
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version 2
18 * of the License, or (at your option) any later version.
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
34 #ifdef HAVE_SYS_TYPES_H
35 # include <sys/types.h>
38 #ifdef HAVE_NETINET_IN_H
39 #include <netinet/in.h>
45 static gint proto_hsrp = -1;
46 static gint ett_hsrp = -1;
48 #define UDP_PORT_HSRP 1985
50 struct hsrp_packet { /* Multicast to 224.0.0.2, TTL 1, UDP, port 1985 */
51 guint8 version; /* RFC2281 describes version 0 */
54 #define HSRP_DEFAULT_HELLOTIME 3
55 guint8 hellotime; /* In seconds */
56 #define HSRP_DEFAULT_HOLDTIME 10
57 guint8 holdtime; /* In seconds */
58 guint8 priority; /* Higher is stronger, highest IP address tie-breaker */
59 guint8 group; /* Identifies the standby group */
61 guint8 auth_data[8]; /* Clear-text password, recommended default is `cisco' */
62 guint32 virt_ip_addr; /* The virtual IP address used by this group */
66 #define HSRP_OPCODE_HELLO 0
67 #define HSRP_OPCODE_COUP 1
68 #define HSRP_OPCODE_RESIGN 2
69 static const value_string hsrp_opcode_vals[] = {
70 {HSRP_OPCODE_HELLO, "Hello"},
71 {HSRP_OPCODE_COUP, "Coup"},
72 {HSRP_OPCODE_RESIGN, "Resign"}
75 #define HSRP_STATE_INITIAL 0
76 #define HSRP_STATE_LEARN 1
77 #define HSRP_STATE_LISTEN 2
78 #define HSRP_STATE_SPEAK 4
79 #define HSRP_STATE_STANDBY 8
80 #define HSRP_STATE_ACTIVE 16
81 static const value_string hsrp_state_vals[] = {
82 {HSRP_STATE_INITIAL, "Initial"},
83 {HSRP_STATE_LEARN, "Learn"},
84 {HSRP_STATE_LISTEN, "Listen"},
85 {HSRP_STATE_SPEAK, "Speak"},
86 {HSRP_STATE_STANDBY, "Standby"},
87 {HSRP_STATE_ACTIVE, "Active"}
91 dissect_hsrp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
93 struct hsrp_packet hsrp;
94 gboolean short_packet = FALSE;
96 if (sizeof(struct hsrp_packet) > END_OF_FRAME)
99 memcpy(&hsrp, pd + offset, sizeof(struct hsrp_packet));
101 if (check_col(fd, COL_PROTOCOL))
102 col_add_str(fd, COL_PROTOCOL, "HSRP");
104 if (check_col(fd, COL_INFO)) {
106 col_add_fstr(fd, COL_INFO, "Short packet, length %u", END_OF_FRAME);
108 col_add_fstr(fd, COL_INFO, "%s (state %s)",
109 val_to_str(hsrp.opcode, hsrp_opcode_vals, "Unknown"),
110 val_to_str(hsrp.state, hsrp_state_vals, "Unknown"));
115 proto_tree *hsrp_tree;
116 guint8 auth_buf[sizeof(hsrp.auth_data) + 1];
119 dissect_data(pd, offset, fd, tree);
123 ti = proto_tree_add_item(tree, proto_hsrp, NullTVB, offset, END_OF_FRAME, NULL);
124 hsrp_tree = proto_item_add_subtree(ti, ett_hsrp);
126 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Version: %u", hsrp.version);
127 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Opcode: %u (%s)", hsrp.opcode,
128 val_to_str(hsrp.opcode, hsrp_opcode_vals, "Unknown"));
129 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "State: %u (%s)", hsrp.state,
130 val_to_str(hsrp.state, hsrp_state_vals, "Unknown"));
132 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Hellotime: %u second%s (%sdefault)",
133 hsrp.hellotime, plurality(hsrp.hellotime, "", "s"),
134 (hsrp.hellotime == HSRP_DEFAULT_HELLOTIME) ? "" : "non-");
135 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Holdtime: %u second%s (%sdefault)",
136 hsrp.holdtime, plurality(hsrp.holdtime, "", "s"),
137 (hsrp.holdtime == HSRP_DEFAULT_HOLDTIME) ? "" : "non-");
138 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Priority: %u", hsrp.priority);
139 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Group: %u", hsrp.group);
140 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 1, "Reserved: 0x%x", hsrp.reserved);
142 memcpy(auth_buf, hsrp.auth_data, sizeof(hsrp.auth_data));
143 auth_buf[sizeof(auth_buf)] = '\0';
144 proto_tree_add_text(hsrp_tree, NullTVB, offset, 8, "Authentication Data: `%s'", auth_buf);
147 proto_tree_add_text(hsrp_tree, NullTVB, offset++, 4, "Virtual IP address: %s",
148 ip_to_str((guint8 *)&hsrp.virt_ip_addr));
155 void proto_register_hsrp(void)
157 static gint *ett[] = {
161 proto_hsrp = proto_register_protocol("Cisco Hot Standby Router Protocol", "hsrp");
162 proto_register_subtree_array(ett, array_length(ett));
168 proto_reg_handoff_hsrp(void)
170 dissector_add("udp.port", UDP_PORT_HSRP, dissect_hsrp);