pcap-common.h revision 335640 
1/*
2 * Copyright (c) 1993, 1994, 1995, 1996, 1997
3 *	The Regents of the University of California.  All rights reserved.
4 *
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
16 * written permission.
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.
20 *
21 * pcap-common.h - common code for pcap and pcapng files
22 */
23
24/*
25 * We use the "receiver-makes-right" approach to byte order,
26 * because time is at a premium when we are writing the file.
27 * In other words, the pcap_file_header and pcap_pkthdr,
28 * records are written in host byte order.
29 * Note that the bytes of packet data are written out in the order in
30 * which they were received, so multi-byte fields in packets are not
31 * written in host byte order, they're written in whatever order the
32 * sending machine put them in.
33 *
34 * ntoh[ls] aren't sufficient because we might need to swap on a big-endian
35 * machine (if the file was written in little-end order).
36 */
37#define	SWAPLONG(y) \
38((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
39#define	SWAPSHORT(y) \
40	( (((y)&0xff)<<8) | ((u_short)((y)&0xff00)>>8) )
41
42extern int dlt_to_linktype(int dlt);
43
44extern int linktype_to_dlt(int linktype);
45
46extern void swap_pseudo_headers(int linktype, struct pcap_pkthdr *hdr,
47    u_char *data);
48
49extern u_int max_snaplen_for_dlt(int dlt);
50