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m241Neelima/vxworks-6.9/target/h/arch/i86/in_cksum.h
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2026-07-30 11:19:44 +05:30

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C

/* in_cksum.h - x86 version in_cksum header file */
/* Copyright 2001-2002 Wind River Systems, Inc. */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from tahoe: in_cksum.c 1.2 86/01/05
* from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
* from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
* $FreeBSD: src/sys/i386/include/in_cksum.h,v 1.7.2.1 2000/05/05 13:37:00 jlemon Exp $
*/
/*
modification history
--------------------
01f,25aug05,dlk Add section tags.
01e,24mar04,m_h Internet Checksum
01d,18mar04,m_h moved to arch/i86
01c,20nov03,niq Remove copyright_wrs.h file inclusion
01c,18nov03,rp updated header file path
01b,25jul02,rvr removed DCC specific code
01a,13sep01,hsh Created from BSD 4.3
*/
#ifndef _MACHINE_IN_CKSUM_H_
#define _MACHINE_IN_CKSUM_H_ 1
#include <sys/cdefs.h>
/*
* in_cksum_hdr - checksum on header only
*
* It is useful to have an Internet checksum routine which is inlineable
* and optimized specifically for the task of computing IP header checksums
* in the normal case (where there are no options and the header length is
* therefore always exactly five 32-bit words.
*/
static __inline u_int
in_cksum_hdr
(
const struct ip *ip
)
{
register u_int sum = 0;
int hlen = sizeof (struct ip);
register u_short *w = (u_short *) ip;
u_short remaining = 0;
while (hlen > 1)
{
sum += *w++;
hlen -= 2;
}
if (hlen == 1)
{
*(u_char *) (&remaining) = *(u_char *) w;
sum += remaining;
}
sum = (sum & 0xffff) + (sum >> 16);
if (sum > 0xffff)
sum -= 0xffff;
return ~sum & 0xffff;
}
/*
* in_cksum_update
*/
static __inline void
in_cksum_update
(
struct ip *ip
)
{
int __tmpsum;
__tmpsum = (int)ntohs(ip->ip_sum) + 256;
ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
}
/*
* in_pseudo - pre-checksum parts of pseudo-header
*
* Compute significant parts of the IPv4 checksum pseudo-header * for use in a
* delayed TCP/UDP checksum calculation.
*
* Args:
*
* src Source IP address
* dst Destination IP address
* lenproto htons(proto-hdr-len + proto-number)
*/
static __inline u_int16_t in_pseudo
(
u_int32_t src,
u_int32_t dst,
u_int32_t lenproto
)
{
u_int32_t sum;
sum = lenproto +
(u_int16_t)(src >> 16) +
(u_int16_t)(src /*& 0xffff*/) +
(u_int16_t)(dst >> 16) +
(u_int16_t)(dst /*& 0xffff*/);
sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/);
if (sum > 0xffff)
sum -= 0xffff;
return (sum);
}
/*
* in_addword - Add two 16-bit workd
*
* Add the two 16-bit network-order values, carry, and return.
*/
static __inline u_int16_t in_addword
(
u_int16_t a,
u_int16_t b
)
{
u_int32_t sum = a + b;
if (sum > 0xffff)
sum -= 0xffff;
return (sum);
}
_WRS_FASTTEXT
u_short in_cksum_skip(struct mbuf *m, int len, int skip);
#endif /* _MACHINE_IN_CKSUM_H_ */