2 * Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
25 static const char rcsid[] =
26 "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.41.4.1 2002/06/01 23:51:15 guy Exp $ (LBL)";
33 #include <sys/param.h>
35 #include <sys/socket.h>
37 #include <netinet/in.h>
43 #include "interface.h"
44 #include "addrtoname.h"
52 #define AF_NS 6 /* XEROX NS protocols */
56 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order
57 * 32-bit integer that specifies the family, e.g. AF_INET.
59 * Note here that "host" refers to the host on which the packets were
60 * captured; that isn't necessarily *this* host.
62 * The OpenBSD DLT_LOOP packet header is the same, except that the integer
63 * is in network byte order.
68 null_print(u_int family, u_int length)
71 printf("AF %u ", family);
90 printf("AF %u ", family);
94 printf("%d: ", length);
98 * Byte-swap a 32-bit number.
99 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
100 * big-endian platforms.)
102 #define SWAPLONG(y) \
103 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
106 null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
108 u_int length = h->len;
109 u_int caplen = h->caplen;
116 memcpy((char *)&family, (char *)p, sizeof(family));
119 * This isn't necessarily in our host byte order; if this is
120 * a DLT_LOOP capture, it's in network byte order, and if
121 * this is a DLT_NULL capture from a machine with the opposite
122 * byte-order, it's in the opposite byte order from ours.
124 * If the upper 16 bits aren't all zero, assume it's byte-swapped.
126 if ((family & 0xFFFF0000) != 0)
127 family = SWAPLONG(family);
130 * Some printers want to get back at the link level addresses,
131 * and/or check that they're not walking off the end of the packet.
132 * Rather than pass them all the way down, we set these globals.
135 snapend = p + caplen;
137 length -= NULL_HDRLEN;
139 ip = (struct ip *)(p + NULL_HDRLEN);
142 null_print(family, length);
146 ip_print((const u_char *)ip, length);
150 ip6_print((const u_char *)ip, length);
154 printf("ip v%d", IP_V(ip));
159 default_print((const u_char *)ip, caplen - NULL_HDRLEN);