90ae06d6ac
Submitted by: Mike Mitchell, supervisor@alb.asctmd.com This is a bulk mport of Mike's IPX/SPX protocol stacks and all the related gunf that goes with it.. it is not guaranteed to work 100% correctly at this time but as we had several people trying to work on it I figured it would be better to get it checked in so they could all get teh same thing to work on.. Mikes been using it for a year or so but on 2.0 more changes and stuff will be merged in from other developers now that this is in. Mike Mitchell, Network Engineer AMTECH Systems Corporation, Technology and Manufacturing 8600 Jefferson Street, Albuquerque, New Mexico 87113 (505) 856-8000 supervisor@alb.asctmd.com
206 lines
6.4 KiB
C
206 lines
6.4 KiB
C
/*
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* Copyright (c) 1995, Mike Mitchell
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* Copyright (c) 1982, 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)ipx_cksum.c
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*/
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#include <sys/param.h>
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#include <sys/mbuf.h>
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/*
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* Checksum routine for Network Systems Protocol Packets (Big-Endian).
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*
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* This routine is very heavily used in the network
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* code and should be modified for each CPU to be as fast as possible.
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*/
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#define ADDCARRY(x) { if ((x) > 65535) (x) -= 65535; }
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#define FOLD(x) {l_util.l = (x); (x) = l_util.s[0] + l_util.s[1]; ADDCARRY(x);}
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u_short
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ipx_cksum(m, len)
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register struct mbuf *m;
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register int len;
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{
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register u_short *w;
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register int sum = 0;
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register int mlen = 0;
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register int sum2;
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union {
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u_short s[2];
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long l;
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} l_util;
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for (;m && len; m = m->m_next) {
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if (m->m_len == 0)
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continue;
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/*
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* Each trip around loop adds in
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* word from one mbuf segment.
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*/
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w = mtod(m, u_short *);
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if (mlen == -1) {
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/*
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* There is a byte left from the last segment;
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* ones-complement add it into the checksum.
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*/
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#if BYTE_ORDER == BIG_ENDIAN
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sum += *(u_char *)w;
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#else
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sum += *(u_char *)w << 8;
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#endif
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sum += sum;
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w = (u_short *)(1 + (char *)w);
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mlen = m->m_len - 1;
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len--;
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FOLD(sum);
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} else
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mlen = m->m_len;
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if (len < mlen)
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mlen = len;
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len -= mlen;
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/*
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* We can do a 16 bit ones complement sum using
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* 32 bit arithmetic registers for adding,
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* with carries from the low added
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* into the high (by normal carry-chaining)
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* so long as we fold back before 16 carries have occured.
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*/
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if (1 & (int) w)
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goto uuuuglyy;
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#ifndef TINY
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/* -DTINY reduces the size from 1250 to 550, but slows it down by 22% */
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while ((mlen -= 32) >= 0) {
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sum += w[0]; sum += sum; sum += w[1]; sum += sum;
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sum += w[2]; sum += sum; sum += w[3]; sum += sum;
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sum += w[4]; sum += sum; sum += w[5]; sum += sum;
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sum += w[6]; sum += sum; sum += w[7]; sum += sum;
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FOLD(sum);
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sum += w[8]; sum += sum; sum += w[9]; sum += sum;
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sum += w[10]; sum += sum; sum += w[11]; sum += sum;
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sum += w[12]; sum += sum; sum += w[13]; sum += sum;
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sum += w[14]; sum += sum; sum += w[15]; sum += sum;
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FOLD(sum);
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w += 16;
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}
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mlen += 32;
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#endif
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while ((mlen -= 8) >= 0) {
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sum += w[0]; sum += sum; sum += w[1]; sum += sum;
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sum += w[2]; sum += sum; sum += w[3]; sum += sum;
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FOLD(sum);
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w += 4;
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}
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mlen += 8;
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while ((mlen -= 2) >= 0) {
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sum += *w++; sum += sum;
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}
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goto commoncase;
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uuuuglyy:
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#if BYTE_ORDER == BIG_ENDIAN
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#define ww(n) (((u_char *)w)[n + n + 1])
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#define vv(n) (((u_char *)w)[n + n])
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#else
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#if BYTE_ORDER == LITTLE_ENDIAN
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#define vv(n) (((u_char *)w)[n + n + 1])
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#define ww(n) (((u_char *)w)[n + n])
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#endif
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#endif
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sum2 = 0;
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#ifndef TINY
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while ((mlen -= 32) >= 0) {
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sum += ww(0); sum += sum; sum += ww(1); sum += sum;
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sum += ww(2); sum += sum; sum += ww(3); sum += sum;
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sum += ww(4); sum += sum; sum += ww(5); sum += sum;
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sum += ww(6); sum += sum; sum += ww(7); sum += sum;
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FOLD(sum);
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sum += ww(8); sum += sum; sum += ww(9); sum += sum;
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sum += ww(10); sum += sum; sum += ww(11); sum += sum;
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sum += ww(12); sum += sum; sum += ww(13); sum += sum;
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sum += ww(14); sum += sum; sum += ww(15); sum += sum;
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FOLD(sum);
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sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
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sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
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sum2 += vv(4); sum2 += sum2; sum2 += vv(5); sum2 += sum2;
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sum2 += vv(6); sum2 += sum2; sum2 += vv(7); sum2 += sum2;
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FOLD(sum2);
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sum2 += vv(8); sum2 += sum2; sum2 += vv(9); sum2 += sum2;
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sum2 += vv(10); sum2 += sum2; sum2 += vv(11); sum2 += sum2;
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sum2 += vv(12); sum2 += sum2; sum2 += vv(13); sum2 += sum2;
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sum2 += vv(14); sum2 += sum2; sum2 += vv(15); sum2 += sum2;
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FOLD(sum2);
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w += 16;
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}
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mlen += 32;
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#endif
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while ((mlen -= 8) >= 0) {
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sum += ww(0); sum += sum; sum += ww(1); sum += sum;
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sum += ww(2); sum += sum; sum += ww(3); sum += sum;
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FOLD(sum);
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sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
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sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
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FOLD(sum2);
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w += 4;
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}
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mlen += 8;
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while ((mlen -= 2) >= 0) {
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sum += ww(0); sum += sum;
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sum2 += vv(0); sum2 += sum2;
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w++;
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}
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sum += (sum2 << 8);
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commoncase:
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if (mlen == -1) {
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#if BYTE_ORDER == BIG_ENDIAN
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sum += *(u_char *)w << 8;
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#else
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sum += *(u_char *)w;
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#endif
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}
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FOLD(sum);
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}
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if (mlen == -1) {
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/* We had an odd number of bytes to sum; assume a garbage
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byte of zero and clean up */
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sum += sum;
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FOLD(sum);
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}
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/*
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* sum has already been kept to low sixteen bits.
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* just examine result and exit.
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*/
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if(sum==0xffff) sum = 0;
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return (sum);
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}
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