1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	from tahoe:	in_cksum.c	1.2	86/01/05
32 *	from:		@(#)in_cksum.c	1.3 (Berkeley) 1/19/91
33 *	from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
34 * $FreeBSD$
35 */
36
37#ifndef _MACHINE_IN_CKSUM_H_
38#define	_MACHINE_IN_CKSUM_H_	1
39
40#ifndef _SYS_CDEFS_H_
41#error this file needs sys/cdefs.h as a prerequisite
42#endif
43
44#include <sys/cdefs.h>
45
46#define in_cksum(m, len)	in_cksum_skip(m, len, 0)
47
48#if defined(IPVERSION) && (IPVERSION == 4)
49/*
50 * It it useful to have an Internet checksum routine which is inlineable
51 * and optimized specifically for the task of computing IP header checksums
52 * in the normal case (where there are no options and the header length is
53 * therefore always exactly five 32-bit words.
54 */
55#ifdef __CC_SUPPORTS___INLINE
56
57static __inline void
58in_cksum_update(struct ip *ip)
59{
60	int __tmpsum;
61	__tmpsum = (int)ntohs(ip->ip_sum) + 256;
62	ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
63}
64
65#else
66
67#define	in_cksum_update(ip) \
68	do { \
69		int __tmpsum; \
70		__tmpsum = (int)ntohs(ip->ip_sum) + 256; \
71		ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
72	} while(0)
73
74#endif
75#endif
76
77#ifdef _KERNEL
78#if defined(IPVERSION) && (IPVERSION == 4)
79u_int in_cksum_hdr(const struct ip *ip);
80#endif
81u_short	in_addword(u_short sum, u_short b);
82u_short	in_pseudo(u_int sum, u_int b, u_int c);
83u_short	in_cksum_skip(struct mbuf *m, int len, int skip);
84#endif
85
86#endif /* _MACHINE_IN_CKSUM_H_ */
87