xref: /freebsd/sys/amd64/include/in_cksum.h (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
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 
57 static __inline void
58 in_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)
79 u_int in_cksum_hdr(const struct ip *ip);
80 #endif
81 u_short	in_addword(u_short sum, u_short b);
82 u_short	in_pseudo(u_int sum, u_int b, u_int c);
83 u_short	in_cksum_skip(struct mbuf *m, int len, int skip);
84 #endif
85 
86 #endif /* _MACHINE_IN_CKSUM_H_ */
87