_mobile.c

This directory contains source code for tcpdump, a tool for network monitoring and data acquisition

/*      $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 <[e-mail]>
 *
 * 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.
 */

#if 0
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 <stdio.h>

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netdb.h>

#include "interfac.h"
#include "a2name.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 */

#if 0
  static u_int16_t mob_in_cksum (u_short * p, int len);
#else
  #define mob_in_cksum(p,len) in_cksum(p,len,0)
#endif

/*
 * 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)
  {
    PUTS ("[|mobile]");
    return;
  }

  proto = EXTRACT_16BITS (&mob->proto);
  crc = EXTRACT_16BITS (&mob->hcheck);
  if (proto & OSRC_PRES)
  {
    osp = 1;
    cp += 4;
  }

  if (osp)
  {
    PUTS ("[S] ");
    if (vflag)
       PRINTF ("%s ", ipaddr_string (&mob->osrc));
  }
  else
    PUTS ("[] ");

  if (vflag)
     PRINTF ("> %s (oproto=%d)", ipaddr_string (&mob->odst), proto >> 8);

  if (mob_in_cksum ((u_short *) mob, osp ? 12 : 8) != 0)
     PRINTF (" (bad checksum %d)", crc);
}

#ifdef NOT_USED
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);
}
#endif