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/* $OpenBSD: print-mobile.c,v 1.6 2020/01/24 22:46:37 procter Exp $ */
/* $NetBSD: print-mobile.c,v 1.3 1999/07/26 06:11:57 itojun 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.
*
* 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/time.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netdb.h>
#include <stdio.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h" /* must come after interface.h */
#define MOBILE_SIZE (8)
struct mobile_ip {
u_int16_t proto;
u_int16_t hcheck;
u_int32_t odst;
u_int32_t osrc;
};
#define OSRC_PRES 0x0080 /* old source is present */
static u_int16_t mob_in_cksum(u_short *p, int len);
/*
* Deencapsulate and print a mobile-tunneled IP datagram
*/
void
mobile_print(const u_char *bp, u_int length)
{
const u_char *cp = bp +8 ;
const struct mobile_ip *mob;
u_short proto,crc;
u_char osp =0; /* old source address present */
mob = (const struct mobile_ip *)bp;
if (length < MOBILE_SIZE) {
printf("[|mobile]");
return;
}
proto = EXTRACT_16BITS(&mob->proto);
crc = EXTRACT_16BITS(&mob->hcheck);
if (proto & OSRC_PRES) {
osp=1;
cp +=4 ;
}
if (osp) {
printf("[S] ");
if (vflag)
printf("%s ",ipaddr_string(&mob->osrc));
} else {
printf("[] ");
}
if (vflag) {
printf("> %s ",ipaddr_string(&mob->odst));
printf("(oproto=%d)",proto>>8);
}
if (mob_in_cksum((u_short *)mob, osp ? 12 : 8)!=0) {
printf(" (bad checksum %d)",crc);
}
return;
}
static u_int16_t mob_in_cksum(u_short *p, int len)
{
u_int32_t sum = 0;
int nwords = len >> 1;
while (nwords-- != 0)
sum += *p++;
if (len & 1) {
union {
u_int16_t w;
u_int32_t c[2];
} u;
u.c[0] = *(u_char *)p;
u.c[1] = 0;
sum += u.w;
}
/* end-around-carry */
sum = (sum >> 16) + (sum & 0xffff);
sum += (sum >> 16);
return (~sum);
}
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