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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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
48 #include <sys/cdefs.h>
50 #define in_cksum(m, len) in_cksum_skip(m, len, 0)
53 * It it useful to have an Internet checksum routine which is inlineable
54 * and optimized specifically for the task of computing IP header checksums
55 * in the normal case (where there are no options and the header length is
56 * therefore always exactly five 32-bit words.
58 #if defined(__GNUCLIKE_ASM)
59 #if defined(IPVERSION) && (IPVERSION == 4)
61 in_cksum_hdr(const struct ip *ip)
73 : "g" (((const u_int32_t *)ip)[0]),
74 "g" (((const u_int32_t *)ip)[1]),
75 "g" (((const u_int32_t *)ip)[2]),
76 "g" (((const u_int32_t *)ip)[3]),
77 "g" (((const u_int32_t *)ip)[4])
80 sum = (sum & 0xffff) + (sum >> 16);
88 in_cksum_update(struct ip *ip)
91 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
92 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
96 static __inline u_short
97 in_addword(u_short sum, u_short b)
109 static __inline u_short
110 in_pseudo(u_int sum, u_int b, u_int c)
121 sum = (sum & 0xffff) + (sum >> 16);
128 #if defined(IPVERSION) && (IPVERSION == 4)
129 #define in_cksum_update(ip) \
132 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
133 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
140 #if !defined(__GNUCLIKE_ASM)
141 #if defined(IPVERSION) && (IPVERSION == 4)
142 u_int in_cksum_hdr(const struct ip *ip);
144 u_short in_addword(u_short sum, u_short b);
145 u_short in_pseudo(u_int sum, u_int b, u_int c);
147 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
150 #endif /* _MACHINE_IN_CKSUM_H_ */