xref: /netbsd-src/external/bsd/tcpdump/dist/print-mobile.c (revision 26ba0b503b498a5194a71ac319838b7f5497f3fe)

/*	NetBSD: print-mobile.c,v 1.2 1998/09/30 08:57:01 hwr Exp  */

/*
 * (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Heiko W.Rupp <hwr@pilhuhn.de>
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-mobile.c,v 1.8 2024/09/02 16:15:32 christos Exp $");
#endif

/* \summary: IPv4 mobility printer */

#include <config.h>

#include "netdissect-stdinc.h"

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

#define MOBILE_SIZE (8)

struct mobile_ip {
	nd_uint16_t proto;
	nd_uint16_t hcheck;
	nd_uint32_t odst;
	nd_uint32_t osrc;
};

#define OSRC_PRES	0x0080	/* old source is present */

/*
 * Deencapsulate and print a mobile-tunneled IP datagram
 */
void
mobile_print(netdissect_options *ndo, const u_char *bp, u_int length)
{
	const struct mobile_ip *mob;
	struct cksum_vec vec[1];
	u_short proto,crc;
	u_char osp =0;			/* old source address present */

	ndo->ndo_protocol = "mobile";
	mob = (const struct mobile_ip *)bp;

	if (length < MOBILE_SIZE || !ND_TTEST_SIZE(mob)) {
		nd_print_trunc(ndo);
		return;
	}
	ND_PRINT("mobile: ");

	proto = GET_BE_U_2(mob->proto);
	crc =  GET_BE_U_2(mob->hcheck);
	if (proto & OSRC_PRES) {
		osp=1;
	}

	if (osp)  {
		ND_PRINT("[S] ");
		if (ndo->ndo_vflag)
			ND_PRINT("%s ", GET_IPADDR_STRING(mob->osrc));
	} else {
		ND_PRINT("[] ");
	}
	if (ndo->ndo_vflag) {
		ND_PRINT("> %s ", GET_IPADDR_STRING(mob->odst));
		ND_PRINT("(oproto=%u)", proto>>8);
	}
	vec[0].ptr = (const uint8_t *)(const void *)mob;
	vec[0].len = osp ? 12 : 8;
	if (in_cksum(vec, 1)!=0) {
		ND_PRINT(" (bad checksum %u)", crc);
	}
}