in_cksum.h revision 236992 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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 * 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.
20 *
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)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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
31 * SUCH DAMAGE.
32 *
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: head/sys/arm/include/in_cksum.h 236992 2012-06-13 05:02:51Z imp $
37 */
38
39#ifndef _MACHINE_IN_CKSUM_H_
40#define	_MACHINE_IN_CKSUM_H_	1
41
42#include <sys/cdefs.h>
43
44#ifdef _KERNEL
45u_short in_cksum(struct mbuf *m, int len);
46u_short in_addword(u_short sum, u_short b);
47u_short in_cksum_skip(struct mbuf *m, int len, int skip);
48u_int do_cksum(const void *, int);
49#if defined(IPVERSION) && (IPVERSION == 4)
50u_int in_cksum_hdr(const struct ip *);
51#endif
52
53static __inline u_short
54in_pseudo(u_int sum, u_int b, u_int c)
55{
56	__asm __volatile("adds %0, %0, %1\n"
57	    		"adcs %0, %0, %2\n"
58			"adc %0, %0, #0\n"
59			: "+r" (sum)
60			: "r" (b), "r" (c));
61	sum = (sum & 0xffff) + (sum >> 16);
62	if (sum > 0xffff)
63		sum -= 0xffff;
64	return (sum);
65}
66
67#endif /* _KERNEL */
68#endif /* _MACHINE_IN_CKSUM_H_ */
69