contrib/tcpdump/tcpdump/print-arp.c

/*
 * Copyright (c) 1988-1990 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 1.16 91/04/19 10:45:56 mccanne Exp $ (LBL)";
#endif

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>

#include "interface.h"
#include "addrtoname.h"

void
arp_print(ap, length, caplen)
        register struct ether_arp *ap;
        int length;
        int caplen;
{
        if ((u_char *)(ap + 1) > snapend) {
                printf("[|arp]");
                return;
        }
        if (length < sizeof(struct ether_arp)) {
                (void)printf("truncated-arp");
                default_print((u_short *)ap, length);
                return;
        }

        NTOHS(ap->arp_hrd);
        NTOHS(ap->arp_pro);
        NTOHS(ap->arp_op);

        if (ap->arp_hrd != ARPHRD_ETHER
            || (ap->arp_pro != ETHERTYPE_IP
                && ap->arp_pro != ETHERTYPE_TRAIL)
            || ap->arp_hln != sizeof(SHA(ap))
            || ap->arp_pln != sizeof(SPA(ap))) {
                (void)printf("arp-req #%d for proto #%d (%d) hardware %d (%d)",
                                ap->arp_op, ap->arp_pro, ap->arp_pln,
                                ap->arp_hrd, ap->arp_hln);
                return;
        }
        if (ap->arp_pro == ETHERTYPE_TRAIL)
                (void)printf("trailer");
        switch (ap->arp_op) {

        case ARPOP_REQUEST:
                (void)printf("arp who-has %s tell %s",
                        ipaddr_string(TPA(ap)),
                        ipaddr_string(SPA(ap)));
                break;

        case ARPOP_REPLY:
                (void)printf("arp reply %s is-at %s",
                        ipaddr_string(SPA(ap)),
                        etheraddr_string(SHA(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", ap->arp_op);
                default_print((u_short *)ap, caplen);
                break;
        }
}