/* $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 * * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifndef lint static const char rcsid[] = "@(#) $Header: /tcpdump/master/tcpdump/print-mobile.c,v 1.2.2.1 2000/01/11 06:58:26 fenner Exp $"; #endif #include #include #include #include #include #include #include #include #include #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) { fputs("[|mobile]", stdout); return; } proto = EXTRACT_16BITS(&mob->proto); crc = EXTRACT_16BITS(&mob->hcheck); if (proto & OSRC_PRES) { osp=1; cp +=4 ; } if (osp) { fputs("[S] ",stdout); if (vflag) (void)printf("%s ",ipaddr_string(&mob->osrc)); } else { fputs("[] ",stdout); } if (vflag) { (void)printf("> %s ",ipaddr_string(&mob->odst)); (void)printf("(oproto=%d)",proto>>8); } if (mob_in_cksum((u_short *)mob, osp ? 12 : 8)!=0) { (void)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_int8_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); }