xref: /freebsd/contrib/tcpdump/print-hsrp.c (revision 4436b51dff5736e74da464946049ea6899a88938)
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
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