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
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12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * from tahoe: in_cksum.c 1.2 86/01/05
34 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
35 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
36 * $FreeBSD: src/sys/i386/include/in_cksum.h,v 1.7.2.2 2002/07/02 04:03:04 jdp Exp $
37 * $DragonFly: src/sys/platform/pc32/include/Attic/in_cksum.h,v 1.4 2003/08/26 21:42:18 rob Exp $
40 #ifndef _MACHINE_IN_CKSUM_H_
41 #define _MACHINE_IN_CKSUM_H_ 1
43 #include <sys/cdefs.h>
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.
53 in_cksum_hdr(const struct ip *ip)
57 /* __volatile is necessary here because the condition codes are used. */
58 #define ADD(n) __asm __volatile ("addl %1, %0" : "+r" (sum) : \
59 "g" (((const u_int32_t *)ip)[n / 4]))
60 #define ADDC(n) __asm __volatile ("adcl %1, %0" : "+r" (sum) : \
61 "g" (((const u_int32_t *)ip)[n / 4]))
62 #define MOP __asm __volatile ("adcl $0, %0" : "+r" (sum))
73 sum = (sum & 0xffff) + (sum >> 16);
81 in_cksum_update(struct ip *ip)
84 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
85 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
88 static __inline u_short
89 in_addword(u_short sum, u_short b)
91 /* __volatile is necessary because the condition codes are used. */
92 __asm __volatile ("addw %1, %0" : "+r" (sum) : "r" (b));
93 __asm __volatile ("adcw $0, %0" : "+r" (sum));
98 static __inline u_short
99 in_pseudo(u_int sum, u_int b, u_int c)
101 /* __volatile is necessary because the condition codes are used. */
102 __asm __volatile ("addl %1, %0" : "+r" (sum) : "g" (b));
103 __asm __volatile ("adcl %1, %0" : "+r" (sum) : "g" (c));
104 __asm __volatile ("adcl $0, %0" : "+r" (sum));
106 sum = (sum & 0xffff) + (sum >> 16);
113 u_int in_cksum_hdr (const struct ip *);
114 #define in_cksum_update(ip) \
117 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
118 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
123 typedef unsigned in_psum_t;
125 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
126 in_psum_t in_cksum_partial(in_psum_t psum, const u_short *w, int len);
127 int in_cksum_finalize(in_psum_t psum);
130 #endif /* _MACHINE_IN_CKSUM_H_ */