/*
* Copyright (C) 2001 Julian Cowley
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

/* \summary: Cisco Hot Standby Router Protocol (HSRP) printer */

/* specification: RFC 2281 for version 1 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-hsrp.c,v 1.9 2024/09/02 16:15:31 christos Exp $");
#endif

#include <config.h>

#include "netdissect-stdinc.h"

#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"

/* HSRP op code types. */
static const char *op_code_str[] = {
       "hello",
       "coup",
       "resign"
};

/* HSRP states and associated names. */
static const struct tok states[] = {
       {  0, "initial" },
       {  1, "learn" },
       {  2, "listen" },
       {  4, "speak" },
       {  8, "standby" },
       { 16, "active" },
       {  0, NULL }
};

/*
* RFC 2281:
*
*  0                   1                   2                   3
*  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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |   Version     |   Op Code     |     State     |   Hellotime   |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |   Holdtime    |   Priority    |     Group     |   Reserved    |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |                      Authentication  Data                     |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |                      Authentication  Data                     |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |                      Virtual IP Address                       |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/

#define HSRP_AUTH_SIZE  8

/* HSRP protocol header. */
struct hsrp {
       nd_uint8_t      hsrp_version;
       nd_uint8_t      hsrp_op_code;
       nd_uint8_t      hsrp_state;
       nd_uint8_t      hsrp_hellotime;
       nd_uint8_t      hsrp_holdtime;
       nd_uint8_t      hsrp_priority;
       nd_uint8_t      hsrp_group;
       nd_uint8_t      hsrp_reserved;
       nd_byte         hsrp_authdata[HSRP_AUTH_SIZE];
       nd_ipv4         hsrp_virtaddr;
};

void
hsrp_print(netdissect_options *ndo, const u_char *bp, u_int len)
{
       const struct hsrp *hp = (const struct hsrp *) bp;
       uint8_t version;

       ndo->ndo_protocol = "hsrp";
       version = GET_U_1(hp->hsrp_version);
       ND_PRINT("HSRPv%u", version);
       if (version != 0)
               return;
       ND_PRINT("-");
       ND_PRINT("%s ",
                tok2strary(op_code_str, "unknown (%u)", GET_U_1(hp->hsrp_op_code)));
       ND_PRINT("%u: ", len);
       ND_PRINT("state=%s ",
                tok2str(states, "Unknown (%u)", GET_U_1(hp->hsrp_state)));
       ND_PRINT("group=%u ", GET_U_1(hp->hsrp_group));
       if (GET_U_1(hp->hsrp_reserved) != 0) {
               ND_PRINT("[reserved=%u!] ", GET_U_1(hp->hsrp_reserved));
       }
       ND_PRINT("addr=%s", GET_IPADDR_STRING(hp->hsrp_virtaddr));
       if (ndo->ndo_vflag) {
               ND_PRINT(" hellotime=");
               unsigned_relts_print(ndo, GET_U_1(hp->hsrp_hellotime));
               ND_PRINT(" holdtime=");
               unsigned_relts_print(ndo, GET_U_1(hp->hsrp_holdtime));
               ND_PRINT(" priority=%u", GET_U_1(hp->hsrp_priority));
               ND_PRINT(" auth=\"");
               /*
                * RFC 2281 Section 5.1 does not specify the encoding of
                * Authentication Data explicitly, but zero padding can be
                * inferred from the "recommended default value".
                */
               nd_printjnp(ndo, hp->hsrp_authdata, HSRP_AUTH_SIZE);
               ND_PRINT("\"");
       }
}