freebsd-nq/contrib/tcpdump/print-null.c
2001-04-03 07:50:46 +00:00

167 lines
4.0 KiB
C

/*
* 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.
*
* $FreeBSD$
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.40 2000/12/16 22:00:50 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>
struct mbuf;
struct rtentry;
#include <netinet/in.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
#ifndef AF_NS
#define AF_NS 6 /* XEROX NS protocols */
#endif
/*
* 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
static void
null_print(u_int family, u_int length)
{
if (nflag)
printf("AF %u ", family);
else {
switch (family) {
case AF_INET:
printf("ip ");
break;
#ifdef INET6
case AF_INET6:
printf("ip6 ");
break;
#endif
case AF_NS:
printf("ns ");
break;
default:
printf("AF %u ", family);
break;
}
}
printf("%d: ", length);
}
/*
* 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))
void
null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
u_int length = h->len;
u_int caplen = h->caplen;
const struct ip *ip;
u_int family;
ts_print(&h->ts);
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);
/*
* Some printers want to get back at the link level addresses,
* and/or check that they're not walking off the end of the packet.
* Rather than pass them all the way down, we set these globals.
*/
packetp = p;
snapend = p + caplen;
length -= NULL_HDRLEN;
ip = (struct ip *)(p + NULL_HDRLEN);
if (eflag)
null_print(family, length);
switch (IP_V(ip)) {
case 4:
ip_print((const u_char *)ip, length);
break;
#ifdef INET6
case 6:
ip6_print((const u_char *)ip, length);
break;
#endif /* INET6 */
default:
printf("ip v%d", IP_V(ip));
break;
}
if (xflag)
default_print((const u_char *)ip, caplen - NULL_HDRLEN);
putchar('\n');
}