2 * Copyright (c) 1990 The Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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 * 4. 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.
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
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22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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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
35 #ifndef _MACHINE_IN_CKSUM_H_
36 #define _MACHINE_IN_CKSUM_H_ 1
39 #error this file needs sys/cdefs.h as a prerequisite
42 #include <sys/cdefs.h>
44 #define in_cksum(m, len) in_cksum_skip(m, len, 0)
46 #if defined(IPVERSION) && (IPVERSION == 4)
48 * It it useful to have an Internet checksum routine which is inlineable
49 * and optimized specifically for the task of computing IP header checksums
50 * in the normal case (where there are no options and the header length is
51 * therefore always exactly five 32-bit words.
53 #ifdef __CC_SUPPORTS___INLINE
56 in_cksum_update(struct ip *ip)
59 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
60 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
65 #define in_cksum_update(ip) \
68 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
69 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
76 #if defined(IPVERSION) && (IPVERSION == 4)
77 u_int in_cksum_hdr(const struct ip *ip);
79 u_short in_addword(u_short sum, u_short b);
80 u_short in_pseudo(u_int sum, u_int b, u_int c);
81 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
84 #endif /* _MACHINE_IN_CKSUM_H_ */