print-vrrp.c revision 313537 
1/*
2 * Copyright (c) 2000 William C. Fenner.
3 *                All rights reserved.
4 *
5 * Kevin Steves <ks@hp.se> July 2000
6 * Modified to:
7 * - print version, type string and packet length
8 * - print IP address count if > 1 (-v)
9 * - verify checksum (-v)
10 * - print authentication string (-v)
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that: (1) source code
14 * distributions retain the above copyright notice and this paragraph
15 * in its entirety, and (2) distributions including binary code include
16 * the above copyright notice and this paragraph in its entirety in
17 * the documentation or other materials provided with the distribution.
18 * The name of William C. Fenner may not be used to endorse or
19 * promote products derived from this software without specific prior
20 * written permission.  THIS SOFTWARE IS PROVIDED ``AS IS'' AND
21 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
22 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE.
24 */
25
26/* \summary: Virtual Router Redundancy Protocol (VRRP) printer */
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include <netdissect-stdinc.h>
33
34#include "netdissect.h"
35#include "extract.h"
36#include "addrtoname.h"
37
38#include "ip.h"
39#include "ipproto.h"
40/*
41 * RFC 2338 (VRRP v2):
42 *
43 *     0                   1                   2                   3
44 *     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
45 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 *    |Version| Type  | Virtual Rtr ID|   Priority    | Count IP Addrs|
47 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 *    |   Auth Type   |   Adver Int   |          Checksum             |
49 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
50 *    |                         IP Address (1)                        |
51 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
52 *    |                            .                                  |
53 *    |                            .                                  |
54 *    |                            .                                  |
55 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
56 *    |                         IP Address (n)                        |
57 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58 *    |                     Authentication Data (1)                   |
59 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60 *    |                     Authentication Data (2)                   |
61 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62 *
63 *
64 * RFC 5798 (VRRP v3):
65 *
66 *    0                   1                   2                   3
67 *    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
68 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
69 *    |                    IPv4 Fields or IPv6 Fields                 |
70 *   ...                                                             ...
71 *    |                                                               |
72 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73 *    |Version| Type  | Virtual Rtr ID|   Priority    |Count IPvX Addr|
74 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75 *    |(rsvd) |     Max Adver Int     |          Checksum             |
76 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77 *    |                                                               |
78 *    +                                                               +
79 *    |                       IPvX Address(es)                        |
80 *    +                                                               +
81 *    |                                                               |
82 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
83 */
84
85/* Type */
86#define	VRRP_TYPE_ADVERTISEMENT	1
87
88static const struct tok type2str[] = {
89	{ VRRP_TYPE_ADVERTISEMENT,	"Advertisement"	},
90	{ 0,				NULL		}
91};
92
93/* Auth Type */
94#define	VRRP_AUTH_NONE		0
95#define	VRRP_AUTH_SIMPLE	1
96#define	VRRP_AUTH_AH		2
97
98static const struct tok auth2str[] = {
99	{ VRRP_AUTH_NONE,		"none"		},
100	{ VRRP_AUTH_SIMPLE,		"simple"	},
101	{ VRRP_AUTH_AH,			"ah"		},
102	{ 0,				NULL		}
103};
104
105void
106vrrp_print(netdissect_options *ndo,
107           register const u_char *bp, register u_int len,
108           register const u_char *bp2, int ttl)
109{
110	int version, type, auth_type = VRRP_AUTH_NONE; /* keep compiler happy */
111	const char *type_s;
112
113	ND_TCHECK(bp[0]);
114	version = (bp[0] & 0xf0) >> 4;
115	type = bp[0] & 0x0f;
116	type_s = tok2str(type2str, "unknown type (%u)", type);
117	ND_PRINT((ndo, "VRRPv%u, %s", version, type_s));
118	if (ttl != 255)
119		ND_PRINT((ndo, ", (ttl %u)", ttl));
120	if (version < 2 || version > 3 || type != VRRP_TYPE_ADVERTISEMENT)
121		return;
122	ND_TCHECK(bp[2]);
123	ND_PRINT((ndo, ", vrid %u, prio %u", bp[1], bp[2]));
124	ND_TCHECK(bp[5]);
125
126	if (version == 2) {
127		auth_type = bp[4];
128		ND_PRINT((ndo, ", authtype %s", tok2str(auth2str, NULL, auth_type)));
129		ND_PRINT((ndo, ", intvl %us, length %u", bp[5], len));
130	} else { /* version == 3 */
131		uint16_t intvl = (bp[4] & 0x0f) << 8 | bp[5];
132		ND_PRINT((ndo, ", intvl %ucs, length %u", intvl, len));
133	}
134
135	if (ndo->ndo_vflag) {
136		int naddrs = bp[3];
137		int i;
138		char c;
139
140		if (version == 2 && ND_TTEST2(bp[0], len)) {
141			struct cksum_vec vec[1];
142
143			vec[0].ptr = bp;
144			vec[0].len = len;
145			if (in_cksum(vec, 1))
146				ND_PRINT((ndo, ", (bad vrrp cksum %x)",
147					EXTRACT_16BITS(&bp[6])));
148		}
149
150		if (version == 3 && ND_TTEST2(bp[0], len)) {
151			uint16_t cksum = nextproto4_cksum(ndo, (const struct ip *)bp2, bp,
152				len, len, IPPROTO_VRRP);
153			if (cksum)
154				ND_PRINT((ndo, ", (bad vrrp cksum %x)",
155					EXTRACT_16BITS(&bp[6])));
156		}
157
158		ND_PRINT((ndo, ", addrs"));
159		if (naddrs > 1)
160			ND_PRINT((ndo, "(%d)", naddrs));
161		ND_PRINT((ndo, ":"));
162		c = ' ';
163		bp += 8;
164		for (i = 0; i < naddrs; i++) {
165			ND_TCHECK(bp[3]);
166			ND_PRINT((ndo, "%c%s", c, ipaddr_string(ndo, bp)));
167			c = ',';
168			bp += 4;
169		}
170		if (version == 2 && auth_type == VRRP_AUTH_SIMPLE) { /* simple text password */
171			ND_TCHECK(bp[7]);
172			ND_PRINT((ndo, " auth \""));
173			if (fn_printn(ndo, bp, 8, ndo->ndo_snapend)) {
174				ND_PRINT((ndo, "\""));
175				goto trunc;
176			}
177			ND_PRINT((ndo, "\""));
178		}
179	}
180	return;
181trunc:
182	ND_PRINT((ndo, "[|vrrp]"));
183}
184