summaryrefslogtreecommitdiff
path: root/print-hsrp.c
blob: 3027826847a9c84fe9a4df9e22c29ed2ba2b1b8e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/*
 * Copyright (C) 2001 Julian Cowley
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* \summary: Cisco Hot Standby Router Protocol (HSRP) printer */

/* specification: RFC 2281 for version 1 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "netdissect-stdinc.h"

#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"

/* HSRP op code types. */
static const char *op_code_str[] = {
	"hello",
	"coup",
	"resign"
};

/* HSRP states and associated names. */
static const struct tok states[] = {
	{  0, "initial" },
	{  1, "learn" },
	{  2, "listen" },
	{  4, "speak" },
	{  8, "standby" },
	{ 16, "active" },
	{  0, NULL }
};

/*
 * RFC 2281:
 *
 *  0                   1                   2                   3
 *  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
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |   Version     |   Op Code     |     State     |   Hellotime   |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |   Holdtime    |   Priority    |     Group     |   Reserved    |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                      Authentication  Data                     |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                      Authentication  Data                     |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                      Virtual IP Address                       |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */

#define HSRP_AUTH_SIZE	8

/* HSRP protocol header. */
struct hsrp {
	nd_uint8_t	hsrp_version;
	nd_uint8_t	hsrp_op_code;
	nd_uint8_t	hsrp_state;
	nd_uint8_t	hsrp_hellotime;
	nd_uint8_t	hsrp_holdtime;
	nd_uint8_t	hsrp_priority;
	nd_uint8_t	hsrp_group;
	nd_uint8_t	hsrp_reserved;
	nd_byte		hsrp_authdata[HSRP_AUTH_SIZE];
	nd_ipv4		hsrp_virtaddr;
};

void
hsrp_print(netdissect_options *ndo, const u_char *bp, u_int len)
{
	const struct hsrp *hp = (const struct hsrp *) bp;
	uint8_t version;

	ndo->ndo_protocol = "hsrp";
	version = GET_U_1(hp->hsrp_version);
	ND_PRINT("HSRPv%u", version);
	if (version != 0)
		return;
	ND_PRINT("-");
	ND_PRINT("%s ",
		 tok2strary(op_code_str, "unknown (%u)", GET_U_1(hp->hsrp_op_code)));
	ND_PRINT("%u: ", len);
	ND_PRINT("state=%s ",
		 tok2str(states, "Unknown (%u)", GET_U_1(hp->hsrp_state)));
	ND_PRINT("group=%u ", GET_U_1(hp->hsrp_group));
	if (GET_U_1(hp->hsrp_reserved) != 0) {
		ND_PRINT("[reserved=%u!] ", GET_U_1(hp->hsrp_reserved));
	}
	ND_PRINT("addr=%s", GET_IPADDR_STRING(hp->hsrp_virtaddr));
	if (ndo->ndo_vflag) {
		ND_PRINT(" hellotime=");
		unsigned_relts_print(ndo, GET_U_1(hp->hsrp_hellotime));
		ND_PRINT(" holdtime=");
		unsigned_relts_print(ndo, GET_U_1(hp->hsrp_holdtime));
		ND_PRINT(" priority=%u", GET_U_1(hp->hsrp_priority));
		ND_PRINT(" auth=\"");
		/*
		 * RFC 2281 Section 5.1 does not specify the encoding of
		 * Authentication Data explicitly, but zero padding can be
		 * inferred from the "recommended default value".
		 */
		nd_printjnp(ndo, hp->hsrp_authdata, HSRP_AUTH_SIZE);
		ND_PRINT("\"");
	}
}