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/*
* Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
* 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 const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.57 2006-03-23 14:58:44 hannes Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <pcap.h>
#include <stdio.h>
#include <string.h>
#include "interface.h"
#include "addrtoname.h"
#include "ip.h"
#ifdef INET6
#include "ip6.h"
#endif
#include "af.h"
/*
* The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order
* 32-bit integer that specifies the family, e.g. AF_INET.
*
* Note here that "host" refers to the host on which the packets were
* captured; that isn't necessarily *this* host.
*
* The OpenBSD DLT_LOOP packet header is the same, except that the integer
* is in network byte order.
*/
#define NULL_HDRLEN 4
/*
* Byte-swap a 32-bit number.
* ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
* big-endian platforms.)
*/
#define SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
static inline void
null_hdr_print(u_int family, u_int length)
{
if (!qflag) {
(void)printf("AF %s (%u)",
tok2str(bsd_af_values,"Unknown",family),family);
} else {
(void)printf("%s",
tok2str(bsd_af_values,"Unknown AF %u",family));
}
(void)printf(", length %u: ", length);
}
/*
* This is the top level routine of the printer. 'p' points
* to the ether header of the packet, 'h->ts' is the timestamp,
* 'h->len' is the length of the packet off the wire, and 'h->caplen'
* is the number of bytes actually captured.
*/
u_int
null_if_print(const struct pcap_pkthdr *h, const u_char *p)
{
u_int length = h->len;
u_int caplen = h->caplen;
u_int family;
if (caplen < NULL_HDRLEN) {
printf("[|null]");
return (NULL_HDRLEN);
}
memcpy((char *)&family, (char *)p, sizeof(family));
/*
* This isn't necessarily in our host byte order; if this is
* a DLT_LOOP capture, it's in network byte order, and if
* this is a DLT_NULL capture from a machine with the opposite
* byte-order, it's in the opposite byte order from ours.
*
* If the upper 16 bits aren't all zero, assume it's byte-swapped.
*/
if ((family & 0xFFFF0000) != 0)
family = SWAPLONG(family);
if (eflag)
null_hdr_print(family, length);
length -= NULL_HDRLEN;
caplen -= NULL_HDRLEN;
p += NULL_HDRLEN;
switch (family) {
case BSD_AFNUM_INET:
ip_print(gndo, p, length);
break;
#ifdef INET6
case BSD_AFNUM_INET6_BSD:
case BSD_AFNUM_INET6_FREEBSD:
case BSD_AFNUM_INET6_DARWIN:
ip6_print(gndo, p, length);
break;
#endif
case BSD_AFNUM_ISO:
isoclns_print(p, length, caplen);
break;
case BSD_AFNUM_APPLETALK:
atalk_print(p, length);
break;
case BSD_AFNUM_IPX:
ipx_print(p, length);
break;
default:
/* unknown AF_ value */
if (!eflag)
null_hdr_print(family, length + NULL_HDRLEN);
if (!suppress_default_print)
default_print(p, caplen);
}
return (NULL_HDRLEN);
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 8
* End:
*/
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