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/* $OpenBSD: print-carp.c,v 1.6 2009/10/27 23:59:55 deraadt Exp $ */
/*
* Copyright (c) 2000 William C. Fenner.
* All rights reserved.
*
* Kevin Steves <ks@hp.se> July 2000
* Modified to:
* - print version, type string and packet length
* - print IP address count if > 1 (-v)
* - verify checksum (-v)
* - print authentication string (-v)
*
* Copyright (c) 2011 Advanced Computing Technologies
* George V. Neille-Neil
*
* Modified to:
* - work correctly with CARP
* - compile into the latest tcpdump
* - print out the counter
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code
* distributions retain the above copyright notice and this paragraph
* in its entirety, and (2) distributions including binary code include
* the above copyright notice and this paragraph in its entirety in
* the documentation or other materials provided with the distribution.
* The name of William C. Fenner may not be used to endorse or
* promote products derived from this software without specific prior
* written permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND
* WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
* LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
*/
#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include "interface.h" /* for checksum structure and functions */
#include "extract.h"
void
carp_print(netdissect_options *ndo, register const u_char *bp, register u_int len, int ttl)
{
int version, type;
const char *type_s;
ND_TCHECK(bp[0]);
version = (bp[0] & 0xf0) >> 4;
type = bp[0] & 0x0f;
if (type == 1)
type_s = "advertise";
else
type_s = "unknown";
ND_PRINT((ndo, "CARPv%d-%s %d: ", version, type_s, len));
if (ttl != 255)
ND_PRINT((ndo, "[ttl=%d!] ", ttl));
if (version != 2 || type != 1)
return;
ND_TCHECK(bp[2]);
ND_TCHECK(bp[5]);
ND_PRINT((ndo, "vhid=%d advbase=%d advskew=%d authlen=%d ",
bp[1], bp[5], bp[2], bp[3]));
if (ndo->ndo_vflag) {
struct cksum_vec vec[1];
vec[0].ptr = (const u_int8_t *)bp;
vec[0].len = len;
if (ND_TTEST2(bp[0], len) && in_cksum(vec, 1))
ND_PRINT((ndo, " (bad carp cksum %x!)",
EXTRACT_16BITS(&bp[6])));
}
ND_PRINT((ndo, "counter=%" PRIu64, EXTRACT_64BITS(&bp[8])));
return;
trunc:
ND_PRINT((ndo, "[|carp]"));
}
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