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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 /* \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