2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1990 The Regents of the University of California.
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8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
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14 * documentation and/or other materials provided with the distribution.
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16 * may be used to endorse or promote products derived from this software
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19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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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
37 #ifndef _MACHINE_IN_CKSUM_H_
38 #define _MACHINE_IN_CKSUM_H_ 1
41 #error this file needs sys/cdefs.h as a prerequisite
44 #include <sys/cdefs.h>
46 #define in_cksum(m, len) in_cksum_skip(m, len, 0)
48 #if defined(IPVERSION) && (IPVERSION == 4)
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.
55 #ifdef __CC_SUPPORTS___INLINE
58 in_cksum_update(struct ip *ip)
61 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
62 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
67 #define in_cksum_update(ip) \
70 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
71 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
78 #if defined(IPVERSION) && (IPVERSION == 4)
79 u_int in_cksum_hdr(const struct ip *ip);
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);
86 #endif /* _MACHINE_IN_CKSUM_H_ */