/* sbcCksum.c - internet checksum routines *//* Copyright 1984-1996 Wind River Systems, Inc. */#include "copyright_wrs.h"/* * Copyright (c) 1988, 1992, 1993 *	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 acknowledgment: *	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. * *	@(#)in_cksum.c	8.1 (Berkeley) 6/10/93 *//*modification history--------------------01b,27sep01,m_h  printf compile warning01a,05jun01,m_h  created from in_cksum.c 01a*//*DESCRIPTIONThis module provides the checksum function in_cksum as a workaround toavoid a hardware bug on the KS32C50100.  The ARMARCH4 version of this functionis implemented using LDR rx, [ry] where the value of ry is not on a word boundary.According to documentation, this should be legal but, on the Samsung CPU,it generates a data abort.*/#include "vxWorks.h"#include "net/systm.h"#include "net/mbuf.h"#include "logLib.h"#include "stdio.h"/* * Checksum routine for Internet Protocol family headers (Portable Version). * * This routine is very heavily used in the network * code and should be modified for each CPU to be as fast as possible. */#define ADDCARRY(x)  (x > 65535 ? x -= 65535 : x)#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}intin_cksum(m, len)	register struct mbuf *m;	register int len;{	register u_short *w;	register int sum = 0;	register int mlen = 0;	int byte_swapped = 0;	union {		char	c[2];		u_short	s;	} s_util;	union {		u_short s[2];		long	l;	} l_util;	for (;m && len; m = m->m_next) {		if (m->m_len == 0)			continue;		w = mtod(m, u_short *);		if (mlen == -1) {			/*			 * The first byte of this mbuf is the continuation			 * of a word spanning between this mbuf and the			 * last mbuf.			 *			 * s_util.c[0] is already saved when scanning previous 			 * mbuf.			 */			s_util.c[1] = *(char *)w;			sum += s_util.s;			w = (u_short *)((char *)w + 1);			mlen = m->m_len - 1;			len--;		} else			mlen = m->m_len;		if (len < mlen)			mlen = len;		len -= mlen;		/*		 * Force to even boundary.		 */		if ((1 & (int) w) && (mlen > 0)) {			REDUCE;			sum <<= 8;			s_util.c[0] = *(u_char *)w;			w = (u_short *)((char *)w + 1);			mlen--;			byte_swapped = 1;		}		/*		 * Unroll the loop to make overhead from		 * branches &c small.		 */		while ((mlen -= 32) >= 0) {			sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];			sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];			sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];			sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];			w += 16;		}		mlen += 32;		while ((mlen -= 8) >= 0) {			sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];			w += 4;		}		mlen += 8;		if (mlen == 0 && byte_swapped == 0)			continue;		REDUCE;		while ((mlen -= 2) >= 0) {			sum += *w++;		}		if (byte_swapped) {			REDUCE;			sum <<= 8;			byte_swapped = 0;			if (mlen == -1) {				s_util.c[1] = *(char *)w;				sum += s_util.s;				mlen = 0;			} else				mlen = -1;		} else if (mlen == -1)			s_util.c[0] = *(char *)w;	}	if (len)		printf("cksum: out of data\n");	if (mlen == -1) {		/* The last mbuf has odd # of bytes. Follow the		   standard (the odd byte may be shifted left by 8 bits		   or not as determined by endian-ness of the machine) */		s_util.c[1] = 0;		sum += s_util.s;	}	REDUCE;	return (~sum & 0xffff);}