xref: /freebsd/contrib/tcpdump/print-hsrp.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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 /* \summary: Cisco Hot Standby Router Protocol (HSRP) printer */
31 
32 /* Cisco Hot Standby Router Protocol (HSRP). */
33 
34 #ifdef HAVE_CONFIG_H
35 #include "config.h"
36 #endif
37 
38 #include <netdissect-stdinc.h>
39 
40 #include "netdissect.h"
41 #include "addrtoname.h"
42 
43 /* HSRP op code types. */
44 static const char *op_code_str[] = {
45 	"hello",
46 	"coup",
47 	"resign"
48 };
49 
50 /* HSRP states and associated names. */
51 static const struct tok states[] = {
52 	{  0, "initial" },
53 	{  1, "learn" },
54 	{  2, "listen" },
55 	{  4, "speak" },
56 	{  8, "standby" },
57 	{ 16, "active" },
58 	{  0, NULL }
59 };
60 
61 /*
62  * RFC 2281:
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  * |   Version     |   Op Code     |     State     |   Hellotime   |
68  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
69  * |   Holdtime    |   Priority    |     Group     |   Reserved    |
70  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71  * |                      Authentication  Data                     |
72  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73  * |                      Authentication  Data                     |
74  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75  * |                      Virtual IP Address                       |
76  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77  */
78 
79 #define HSRP_AUTH_SIZE	8
80 
81 /* HSRP protocol header. */
82 struct hsrp {
83 	uint8_t		hsrp_version;
84 	uint8_t		hsrp_op_code;
85 	uint8_t		hsrp_state;
86 	uint8_t		hsrp_hellotime;
87 	uint8_t		hsrp_holdtime;
88 	uint8_t		hsrp_priority;
89 	uint8_t		hsrp_group;
90 	uint8_t		hsrp_reserved;
91 	uint8_t		hsrp_authdata[HSRP_AUTH_SIZE];
92 	struct in_addr	hsrp_virtaddr;
93 };
94 
95 void
96 hsrp_print(netdissect_options *ndo, register const uint8_t *bp, register u_int len)
97 {
98 	const struct hsrp *hp = (const struct hsrp *) bp;
99 
100 	ND_TCHECK(hp->hsrp_version);
101 	ND_PRINT((ndo, "HSRPv%d", hp->hsrp_version));
102 	if (hp->hsrp_version != 0)
103 		return;
104 	ND_TCHECK(hp->hsrp_op_code);
105 	ND_PRINT((ndo, "-"));
106 	ND_PRINT((ndo, "%s ", tok2strary(op_code_str, "unknown (%d)", hp->hsrp_op_code)));
107 	ND_PRINT((ndo, "%d: ", len));
108 	ND_TCHECK(hp->hsrp_state);
109 	ND_PRINT((ndo, "state=%s ", tok2str(states, "Unknown (%d)", hp->hsrp_state)));
110 	ND_TCHECK(hp->hsrp_group);
111 	ND_PRINT((ndo, "group=%d ", hp->hsrp_group));
112 	ND_TCHECK(hp->hsrp_reserved);
113 	if (hp->hsrp_reserved != 0) {
114 		ND_PRINT((ndo, "[reserved=%d!] ", hp->hsrp_reserved));
115 	}
116 	ND_TCHECK(hp->hsrp_virtaddr);
117 	ND_PRINT((ndo, "addr=%s", ipaddr_string(ndo, &hp->hsrp_virtaddr)));
118 	if (ndo->ndo_vflag) {
119 		ND_PRINT((ndo, " hellotime="));
120 		unsigned_relts_print(ndo, hp->hsrp_hellotime);
121 		ND_PRINT((ndo, " holdtime="));
122 		unsigned_relts_print(ndo, hp->hsrp_holdtime);
123 		ND_PRINT((ndo, " priority=%d", hp->hsrp_priority));
124 		ND_PRINT((ndo, " auth=\""));
125 		if (fn_printn(ndo, hp->hsrp_authdata, sizeof(hp->hsrp_authdata),
126 		    ndo->ndo_snapend)) {
127 			ND_PRINT((ndo, "\""));
128 			goto trunc;
129 		}
130 		ND_PRINT((ndo, "\""));
131 	}
132 	return;
133 trunc:
134 	ND_PRINT((ndo, "[|hsrp]"));
135 }
136