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
88 static 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
98 static const struct tok auth2str[] = {
99 { VRRP_AUTH_NONE, "none" },
100 { VRRP_AUTH_SIMPLE, "simple" },
101 { VRRP_AUTH_AH, "ah" },
102 { 0, NULL }
103 };
104
105 void
vrrp_print(netdissect_options * ndo,register const u_char * bp,register u_int len,register const u_char * bp2,int ttl)106 vrrp_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;
181 trunc:
182 ND_PRINT((ndo, "[|vrrp]"));
183 }
184