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      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