in_cksum.h revision 331722 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	from tahoe:	in_cksum.c	1.2	86/01/05
30 *	from:		@(#)in_cksum.c	1.3 (Berkeley) 1/19/91
31 *	from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
32 *	from: src/sys/alpha/include/in_cksum.h,v 1.7 2005/03/02 21:33:20 joerg
33 * $FreeBSD: stable/11/sys/mips/include/in_cksum.h 331722 2018-03-29 02:50:57Z eadler $
34 */
35
36#ifndef _MACHINE_IN_CKSUM_H_
37#define	_MACHINE_IN_CKSUM_H_	1
38
39#include <sys/cdefs.h>
40
41#define	in_cksum(m, len)	in_cksum_skip(m, len, 0)
42
43#if defined(IPVERSION) && (IPVERSION == 4)
44/*
45 * It it useful to have an Internet checksum routine which is inlineable
46 * and optimized specifically for the task of computing IP header checksums
47 * in the normal case (where there are no options and the header length is
48 * therefore always exactly five 32-bit words.
49 */
50#ifdef __CC_SUPPORTS___INLINE
51
52static __inline void
53in_cksum_update(struct ip *ip)
54{
55	int __tmpsum;
56	__tmpsum = (int)ntohs(ip->ip_sum) + 256;
57	ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
58}
59
60#else
61
62#define	in_cksum_update(ip)						\
63	do {								\
64		int __tmpsum;						\
65		__tmpsum = (int)ntohs(ip->ip_sum) + 256;		\
66		ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));	\
67	} while(0)
68
69#endif
70#endif
71
72#ifdef _KERNEL
73#if defined(IPVERSION) && (IPVERSION == 4)
74u_int in_cksum_hdr(const struct ip *ip);
75#endif
76u_short in_addword(u_short sum, u_short b);
77u_short in_pseudo(u_int sum, u_int b, u_int c);
78u_short in_cksum_skip(struct mbuf *m, int len, int skip);
79#endif
80
81#endif /* _MACHINE_IN_CKSUM_H_ */
82