NetBSD/usr.sbin/tcpdump/print-arp.c

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/* $NetBSD: print-arp.c,v 1.2 1995/03/06 19:11:02 mycroft Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* 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, (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, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char rcsid[] =
"@(#) Header: print-arp.c,v 1.28 94/06/14 20:17:36 leres Exp (LBL)";
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <stdio.h>
#include "interface.h"
#include "addrtoname.h"
static u_char ezero[6];
void
arp_print(register const u_char *bp, int length, int caplen)
{
register const struct ether_arp *ap;
register const struct ether_header *eh;
const u_char *p;
int pro, hrd, op;
ap = (struct ether_arp *)bp;
if ((u_char *)(ap + 1) > snapend) {
printf("[|arp]");
return;
}
if (length < sizeof(struct ether_arp)) {
(void)printf("truncated-arp");
default_print((u_char *)ap, length);
return;
}
/*
* Don't assume alignment.
*/
p = (u_char*)&ap->arp_pro;
pro = (p[0] << 8) | p[1];
p = (u_char*)&ap->arp_hrd;
hrd = (p[0] << 8) | p[1];
p = (u_char*)&ap->arp_op;
op = (p[0] << 8) | p[1];
if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
|| ap->arp_hln != sizeof(SHA(ap))
|| ap->arp_pln != sizeof(SPA(ap))) {
(void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)",
op, pro, ap->arp_pln,
hrd, ap->arp_hln);
return;
}
if (pro == ETHERTYPE_TRAIL)
(void)printf("trailer-");
eh = (struct ether_header *)packetp;
switch (op) {
case ARPOP_REQUEST:
(void)printf("arp who-has %s", ipaddr_string(TPA(ap)));
if (bcmp((char *)ezero, (char *)THA(ap), 6) != 0)
(void)printf(" (%s)", etheraddr_string(THA(ap)));
(void)printf(" tell %s", ipaddr_string(SPA(ap)));
if (bcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
(void)printf(" (%s)", etheraddr_string(SHA(ap)));
break;
case ARPOP_REPLY:
(void)printf("arp reply %s", ipaddr_string(SPA(ap)));
if (bcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
(void)printf(" (%s)", etheraddr_string(SHA(ap)));
(void)printf(" is-at %s", etheraddr_string(SHA(ap)));
if (bcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0)
(void)printf(" (%s)", etheraddr_string(THA(ap)));
break;
case REVARP_REQUEST:
(void)printf("rarp who-is %s tell %s",
etheraddr_string(THA(ap)),
etheraddr_string(SHA(ap)));
break;
case REVARP_REPLY:
(void)printf("rarp reply %s at %s",
etheraddr_string(THA(ap)),
ipaddr_string(TPA(ap)));
break;
default:
(void)printf("arp-#%d", op);
default_print((u_char *)ap, caplen);
return;
}
if (hrd != ARPHRD_ETHER)
printf(" hardware #%d", ap->arp_hrd);
}