1/*-
  2 * SPDX-License-Identifier: BSD-3-Clause
  3 *
  4 * Copyright (c) 1990 The Regents of the University of California.
  5 * All rights reserved.
  6 *
  7 * Redistribution and use in source and binary forms, with or without
  8 * modification, are permitted provided that the following conditions
  9 * are met:
 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.
 18 *
 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
 29 * SUCH DAMAGE.
 30 *
 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
 34 */
 35
 36#ifndef _MACHINE_IN_CKSUM_H_
 37#define	_MACHINE_IN_CKSUM_H_	1
 38
 39#include <sys/cdefs.h>
 40
 41#define in_cksum(m, len)	in_cksum_skip(m, len, 0)
 42
 43/*
 44 * It it useful to have an Internet checksum routine which is inlineable
 45 * and optimized specifically for the task of computing IP header checksums
 46 * in the normal case (where there are no options and the header length is
 47 * therefore always exactly five 32-bit words.
 48 */
 49#if defined(IPVERSION) && (IPVERSION == 4)
 50static __inline u_int
 51in_cksum_hdr(const struct ip *ip)
 52{
 53	u_int sum = 0;
 54
 55	__asm(
 56		"addl %1, %0\n"
 57		"adcl %2, %0\n"
 58		"adcl %3, %0\n"
 59		"adcl %4, %0\n"
 60		"adcl %5, %0\n"
 61		"adcl $0, %0"
 62		: "+r" (sum)
 63		: "g" (((const u_int32_t *)ip)[0]),
 64		  "g" (((const u_int32_t *)ip)[1]),
 65		  "g" (((const u_int32_t *)ip)[2]),
 66		  "g" (((const u_int32_t *)ip)[3]),
 67		  "g" (((const u_int32_t *)ip)[4])
 68		: "cc"
 69	);
 70	sum = (sum & 0xffff) + (sum >> 16);
 71	if (sum > 0xffff)
 72		sum -= 0xffff;
 73
 74	return ~sum & 0xffff;
 75}
 76#endif
 77
 78static __inline u_short
 79in_addword(u_short sum, u_short b)
 80{
 81	__asm(
 82		"addw %1, %0\n"
 83		"adcw $0, %0"
 84		: "+r" (sum)
 85		: "g" (b)
 86		: "cc"
 87	);
 88	return (sum);
 89}
 90
 91static __inline u_short
 92in_pseudo(u_int sum, u_int b, u_int c)
 93{
 94	__asm(
 95		"addl %1, %0\n"
 96		"adcl %2, %0\n"
 97		"adcl $0, %0"
 98		: "+r" (sum)
 99		: "g" (b),
100		  "g" (c)
101		: "cc"
102	);
103	sum = (sum & 0xffff) + (sum >> 16);
104	if (sum > 0xffff)
105		sum -= 0xffff;
106	return (sum);
107}
108
109#ifdef _KERNEL
110
111#define	HAVE_MD_IN_CKSUM
112
113u_short in_cksum_skip(struct mbuf *m, int len, int skip);
114#endif /* _KERNEL */
115
116#endif /* _MACHINE_IN_CKSUM_H_ */