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 /* Cisco Hot Standby Router Protocol (HSRP). */
31
32 #define NETDISSECT_REWORKED
33 #ifdef HAVE_CONFIG_H
34 #include "config.h"
35 #endif
36
37 #include <tcpdump-stdinc.h>
38
39 #include "interface.h"
40 #include "addrtoname.h"
41
42 /* HSRP op code types. */
43 static const char *op_code_str[] = {
44 "hello",
45 "coup",
46 "resign"
47 };
48
49 /* HSRP states and associated names. */
50 static const struct tok states[] = {
51 { 0, "initial" },
52 { 1, "learn" },
53 { 2, "listen" },
54 { 4, "speak" },
55 { 8, "standby" },
56 { 16, "active" },
57 { 0, NULL }
58 };
59
60 /*
61 * RFC 2281:
62 *
63 * 0 1 2 3
64 * 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
65 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
66 * | Version | Op Code | State | Hellotime |
67 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
68 * | Holdtime | Priority | Group | Reserved |
69 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
70 * | Authentication Data |
71 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
72 * | Authentication Data |
73 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
74 * | Virtual IP Address |
75 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
76 */
77
78 #define HSRP_AUTH_SIZE 8
79
80 /* HSRP protocol header. */
81 struct hsrp {
82 uint8_t hsrp_version;
83 uint8_t hsrp_op_code;
84 uint8_t hsrp_state;
85 uint8_t hsrp_hellotime;
86 uint8_t hsrp_holdtime;
87 uint8_t hsrp_priority;
88 uint8_t hsrp_group;
89 uint8_t hsrp_reserved;
90 uint8_t hsrp_authdata[HSRP_AUTH_SIZE];
91 struct in_addr hsrp_virtaddr;
92 };
93
94 void
hsrp_print(netdissect_options * ndo,register const uint8_t * bp,register u_int len)95 hsrp_print(netdissect_options *ndo, register const uint8_t *bp, register u_int len)
96 {
97 struct hsrp *hp = (struct hsrp *) bp;
98
99 ND_TCHECK(hp->hsrp_version);
100 ND_PRINT((ndo, "HSRPv%d", hp->hsrp_version));
101 if (hp->hsrp_version != 0)
102 return;
103 ND_TCHECK(hp->hsrp_op_code);
104 ND_PRINT((ndo, "-"));
105 ND_PRINT((ndo, "%s ", tok2strary(op_code_str, "unknown (%d)", hp->hsrp_op_code)));
106 ND_PRINT((ndo, "%d: ", len));
107 ND_TCHECK(hp->hsrp_state);
108 ND_PRINT((ndo, "state=%s ", tok2str(states, "Unknown (%d)", hp->hsrp_state)));
109 ND_TCHECK(hp->hsrp_group);
110 ND_PRINT((ndo, "group=%d ", hp->hsrp_group));
111 ND_TCHECK(hp->hsrp_reserved);
112 if (hp->hsrp_reserved != 0) {
113 ND_PRINT((ndo, "[reserved=%d!] ", hp->hsrp_reserved));
114 }
115 ND_TCHECK(hp->hsrp_virtaddr);
116 ND_PRINT((ndo, "addr=%s", ipaddr_string(ndo, &hp->hsrp_virtaddr)));
117 if (ndo->ndo_vflag) {
118 ND_PRINT((ndo, " hellotime="));
119 relts_print(ndo, hp->hsrp_hellotime);
120 ND_PRINT((ndo, " holdtime="));
121 relts_print(ndo, hp->hsrp_holdtime);
122 ND_PRINT((ndo, " priority=%d", hp->hsrp_priority));
123 ND_PRINT((ndo, " auth=\""));
124 if (fn_printn(ndo, hp->hsrp_authdata, sizeof(hp->hsrp_authdata),
125 ndo->ndo_snapend)) {
126 ND_PRINT((ndo, "\""));
127 goto trunc;
128 }
129 ND_PRINT((ndo, "\""));
130 }
131 return;
132 trunc:
133 ND_PRINT((ndo, "[|hsrp]"));
134 }
135