2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1990 The Regents of the University of California.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
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
40 #include <sys/cdefs.h>
42 #define in_cksum(m, len) in_cksum_skip(m, len, 0)
44 #if defined(IPVERSION) && (IPVERSION == 4)
46 * It it useful to have an Internet checksum routine which is inlineable
47 * and optimized specifically for the task of computing IP header checksums
48 * in the normal case (where there are no options and the header length is
49 * therefore always exactly five 32-bit words.
51 #ifdef __CC_SUPPORTS___INLINE
54 in_cksum_update(struct ip *ip)
57 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
58 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
63 #define in_cksum_update(ip) \
66 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
67 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
74 #if defined(IPVERSION) && (IPVERSION == 4)
75 u_int in_cksum_hdr(const struct ip *ip);
77 u_short in_addword(u_short sum, u_short b);
78 u_short in_pseudo(u_int sum, u_int b, u_int c);
79 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
82 #endif /* _MACHINE_IN_CKSUM_H_ */