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 #include <config.h>
29
30 #include "netdissect-stdinc.h"
31
32 #include "netdissect.h"
33 #include "extract.h"
34 #include "addrtoname.h"
35
36 #include "ip.h"
37 #include "ipproto.h"
38 /*
39 * RFC 2338 (VRRP v2):
40 *
41 * 0 1 2 3
42 * 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
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * |Version| Type | Virtual Rtr ID| Priority | Count IP Addrs|
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 * | Auth Type | Adver Int | Checksum |
47 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 * | IP Address (1) |
49 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
50 * | . |
51 * | . |
52 * | . |
53 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
54 * | IP Address (n) |
55 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
56 * | Authentication Data (1) |
57 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58 * | Authentication Data (2) |
59 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60 *
61 *
62 * RFC 5798 (VRRP v3):
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 * | IPv4 Fields or IPv6 Fields |
68 * ... ...
69 * | |
70 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71 * |Version| Type | Virtual Rtr ID| Priority |Count IPvX Addr|
72 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73 * |(rsvd) | Max Adver Int | Checksum |
74 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75 * | |
76 * + +
77 * | IPvX Address(es) |
78 * + +
79 * | |
80 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
81 */
82
83 /* Type */
84 #define VRRP_TYPE_ADVERTISEMENT 1
85
86 static const struct tok type2str[] = {
87 { VRRP_TYPE_ADVERTISEMENT, "Advertisement" },
88 { 0, NULL }
89 };
90
91 /* Auth Type */
92 #define VRRP_AUTH_NONE 0
93 #define VRRP_AUTH_SIMPLE 1
94 #define VRRP_AUTH_AH 2
95
96 static const struct tok auth2str[] = {
97 { VRRP_AUTH_NONE, "none" },
98 { VRRP_AUTH_SIMPLE, "simple" },
99 { VRRP_AUTH_AH, "ah" },
100 { 0, NULL }
101 };
102
103 void
vrrp_print(netdissect_options * ndo,const u_char * bp,u_int len,const u_char * bp2,int ttl,int ver)104 vrrp_print(netdissect_options *ndo,
105 const u_char *bp, u_int len,
106 const u_char *bp2, int ttl,
107 int ver)
108 {
109 int version, type, auth_type = VRRP_AUTH_NONE; /* keep compiler happy */
110 const char *type_s;
111
112 ndo->ndo_protocol = "vrrp";
113 nd_print_protocol_caps(ndo);
114 version = (GET_U_1(bp) & 0xf0) >> 4;
115 type = GET_U_1(bp) & 0x0f;
116 type_s = tok2str(type2str, "unknown type (%u)", type);
117 ND_PRINT("v%u, %s", version, type_s);
118 if (ttl != 255)
119 ND_PRINT(", (ttl %u)", ttl);
120 if (version < 2 || version > 3 || type != VRRP_TYPE_ADVERTISEMENT)
121 return;
122 ND_PRINT(", vrid %u, prio %u", GET_U_1(bp + 1), GET_U_1(bp + 2));
123
124 if (version == 2) {
125 auth_type = GET_U_1(bp + 4);
126 ND_PRINT(", authtype %s", tok2str(auth2str, NULL, auth_type));
127 ND_PRINT(", intvl %us, length %u", GET_U_1(bp + 5), len);
128 } else { /* version == 3 */
129 uint16_t intvl = (GET_U_1(bp + 4) & 0x0f) << 8 | GET_U_1(bp + 5);
130 ND_PRINT(", intvl %ucs, length %u", intvl, len);
131 }
132
133 if (ndo->ndo_vflag) {
134 u_int naddrs = GET_U_1(bp + 3);
135 u_int i;
136 char c;
137
138 if (version == 2 && ND_TTEST_LEN(bp, len)) {
139 struct cksum_vec vec[1];
140
141 vec[0].ptr = bp;
142 vec[0].len = len;
143 if (in_cksum(vec, 1))
144 ND_PRINT(", (bad vrrp cksum %x)",
145 GET_BE_U_2(bp + 6));
146 }
147
148 if (version == 3 && ND_TTEST_LEN(bp, len)) {
149 uint16_t cksum;
150
151 if (ver == 4)
152 cksum = nextproto4_cksum(ndo, (const struct ip *)bp2, bp,
153 len, len, IPPROTO_VRRP);
154 else
155 cksum = nextproto6_cksum(ndo, (const struct ip6_hdr *)bp2, bp,
156 len, len, IPPROTO_VRRP);
157 if (cksum)
158 ND_PRINT(", (bad vrrp cksum %x)",
159 GET_BE_U_2(bp + 6));
160 }
161
162 ND_PRINT(", addrs");
163 if (naddrs > 1)
164 ND_PRINT("(%u)", naddrs);
165 ND_PRINT(":");
166 c = ' ';
167 bp += 8;
168 for (i = 0; i < naddrs; i++) {
169 if (ver == 4) {
170 ND_PRINT("%c%s", c, GET_IPADDR_STRING(bp));
171 bp += 4;
172 } else {
173 ND_PRINT("%c%s", c, GET_IP6ADDR_STRING(bp));
174 bp += 16;
175 }
176 c = ',';
177 }
178 if (version == 2 && auth_type == VRRP_AUTH_SIMPLE) { /* simple text password */
179 ND_PRINT(" auth \"");
180 /*
181 * RFC 2338 Section 5.3.10: "If the configured authentication string
182 * is shorter than 8 bytes, the remaining space MUST be zero-filled.
183 */
184 nd_printjnp(ndo, bp, 8);
185 ND_PRINT("\"");
186 }
187 }
188 }
189