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/* specification: RFC 2281 for version 1 */
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#include "extract.h"
43
44/* HSRP op code types. */
45static const char *op_code_str[] = {
46	"hello",
47	"coup",
48	"resign"
49};
50
51/* HSRP states and associated names. */
52static const struct tok states[] = {
53	{  0, "initial" },
54	{  1, "learn" },
55	{  2, "listen" },
56	{  4, "speak" },
57	{  8, "standby" },
58	{ 16, "active" },
59	{  0, NULL }
60};
61
62/*
63 * RFC 2281:
64 *
65 *  0                   1                   2                   3
66 *  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
67 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
68 * |   Version     |   Op Code     |     State     |   Hellotime   |
69 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
70 * |   Holdtime    |   Priority    |     Group     |   Reserved    |
71 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
72 * |                      Authentication  Data                     |
73 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
74 * |                      Authentication  Data                     |
75 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
76 * |                      Virtual IP Address                       |
77 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
78 */
79
80#define HSRP_AUTH_SIZE	8
81
82/* HSRP protocol header. */
83struct hsrp {
84	nd_uint8_t	hsrp_version;
85	nd_uint8_t	hsrp_op_code;
86	nd_uint8_t	hsrp_state;
87	nd_uint8_t	hsrp_hellotime;
88	nd_uint8_t	hsrp_holdtime;
89	nd_uint8_t	hsrp_priority;
90	nd_uint8_t	hsrp_group;
91	nd_uint8_t	hsrp_reserved;
92	nd_byte		hsrp_authdata[HSRP_AUTH_SIZE];
93	nd_ipv4		hsrp_virtaddr;
94};
95
96void
97hsrp_print(netdissect_options *ndo, const u_char *bp, u_int len)
98{
99	const struct hsrp *hp = (const struct hsrp *) bp;
100	uint8_t version;
101
102	ndo->ndo_protocol = "hsrp";
103	version = GET_U_1(hp->hsrp_version);
104	ND_PRINT("HSRPv%u", version);
105	if (version != 0)
106		return;
107	ND_PRINT("-");
108	ND_PRINT("%s ",
109		 tok2strary(op_code_str, "unknown (%u)", GET_U_1(hp->hsrp_op_code)));
110	ND_PRINT("%u: ", len);
111	ND_PRINT("state=%s ",
112		 tok2str(states, "Unknown (%u)", GET_U_1(hp->hsrp_state)));
113	ND_PRINT("group=%u ", GET_U_1(hp->hsrp_group));
114	if (GET_U_1(hp->hsrp_reserved) != 0) {
115		ND_PRINT("[reserved=%u!] ", GET_U_1(hp->hsrp_reserved));
116	}
117	ND_PRINT("addr=%s", GET_IPADDR_STRING(hp->hsrp_virtaddr));
118	if (ndo->ndo_vflag) {
119		ND_PRINT(" hellotime=");
120		unsigned_relts_print(ndo, GET_U_1(hp->hsrp_hellotime));
121		ND_PRINT(" holdtime=");
122		unsigned_relts_print(ndo, GET_U_1(hp->hsrp_holdtime));
123		ND_PRINT(" priority=%u", GET_U_1(hp->hsrp_priority));
124		ND_PRINT(" auth=\"");
125		/*
126		 * RFC 2281 Section 5.1 does not specify the encoding of
127		 * Authentication Data explicitly, but zero padding can be
128		 * inferred from the "recommended default value".
129		 */
130		nd_printjnp(ndo, hp->hsrp_authdata, HSRP_AUTH_SIZE);
131		ND_PRINT("\"");
132	}
133}
134