1/*
2 * Copyright (C) 2001 Julian Cowley
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/* \summary: Cisco Hot Standby Router Protocol (HSRP) printer */
31
32/* Cisco Hot Standby Router Protocol (HSRP). */
33
34#ifdef HAVE_CONFIG_H
35#include "config.h"
36#endif
37
38#include <netdissect-stdinc.h>
39
40#include "netdissect.h"
41#include "addrtoname.h"
42
43/* HSRP op code types. */
44static const char *op_code_str[] = {
45	"hello",
46	"coup",
47	"resign"
48};
49
50/* HSRP states and associated names. */
51static const struct tok states[] = {
52	{  0, "initial" },
53	{  1, "learn" },
54	{  2, "listen" },
55	{  4, "speak" },
56	{  8, "standby" },
57	{ 16, "active" },
58	{  0, NULL }
59};
60
61/*
62 * RFC 2281:
63 *
64 *  0                   1                   2                   3
65 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
66 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
67 * |   Version     |   Op Code     |     State     |   Hellotime   |
68 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
69 * |   Holdtime    |   Priority    |     Group     |   Reserved    |
70 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71 * |                      Authentication  Data                     |
72 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73 * |                      Authentication  Data                     |
74 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75 * |                      Virtual IP Address                       |
76 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77 */
78
79#define HSRP_AUTH_SIZE	8
80
81/* HSRP protocol header. */
82struct hsrp {
83	uint8_t		hsrp_version;
84	uint8_t		hsrp_op_code;
85	uint8_t		hsrp_state;
86	uint8_t		hsrp_hellotime;
87	uint8_t		hsrp_holdtime;
88	uint8_t		hsrp_priority;
89	uint8_t		hsrp_group;
90	uint8_t		hsrp_reserved;
91	uint8_t		hsrp_authdata[HSRP_AUTH_SIZE];
92	struct in_addr	hsrp_virtaddr;
93};
94
95void
96hsrp_print(netdissect_options *ndo, register const uint8_t *bp, register u_int len)
97{
98	const struct hsrp *hp = (const struct hsrp *) bp;
99
100	ND_TCHECK(hp->hsrp_version);
101	ND_PRINT((ndo, "HSRPv%d", hp->hsrp_version));
102	if (hp->hsrp_version != 0)
103		return;
104	ND_TCHECK(hp->hsrp_op_code);
105	ND_PRINT((ndo, "-"));
106	ND_PRINT((ndo, "%s ", tok2strary(op_code_str, "unknown (%d)", hp->hsrp_op_code)));
107	ND_PRINT((ndo, "%d: ", len));
108	ND_TCHECK(hp->hsrp_state);
109	ND_PRINT((ndo, "state=%s ", tok2str(states, "Unknown (%d)", hp->hsrp_state)));
110	ND_TCHECK(hp->hsrp_group);
111	ND_PRINT((ndo, "group=%d ", hp->hsrp_group));
112	ND_TCHECK(hp->hsrp_reserved);
113	if (hp->hsrp_reserved != 0) {
114		ND_PRINT((ndo, "[reserved=%d!] ", hp->hsrp_reserved));
115	}
116	ND_TCHECK(hp->hsrp_virtaddr);
117	ND_PRINT((ndo, "addr=%s", ipaddr_string(ndo, &hp->hsrp_virtaddr)));
118	if (ndo->ndo_vflag) {
119		ND_PRINT((ndo, " hellotime="));
120		unsigned_relts_print(ndo, hp->hsrp_hellotime);
121		ND_PRINT((ndo, " holdtime="));
122		unsigned_relts_print(ndo, hp->hsrp_holdtime);
123		ND_PRINT((ndo, " priority=%d", hp->hsrp_priority));
124		ND_PRINT((ndo, " auth=\""));
125		if (fn_printn(ndo, hp->hsrp_authdata, sizeof(hp->hsrp_authdata),
126		    ndo->ndo_snapend)) {
127			ND_PRINT((ndo, "\""));
128			goto trunc;
129		}
130		ND_PRINT((ndo, "\""));
131	}
132	return;
133trunc:
134	ND_PRINT((ndo, "[|hsrp]"));
135}
136