bbb8727584
just for reference purposes. This commit includes 1.4 -> 1.4.1 sync for kame branch. The branch does not compile at all (due to the lack of ALTQ and some other source code). Please do not try to modify the branch, this is just for referenre purposes. synchronization to latest KAME will take place on HEAD branch soon.
215 lines
6.9 KiB
C
215 lines
6.9 KiB
C
/* $NetBSD: in4_cksum.c,v 1.1.2.1 1999/11/30 13:35:24 itojun Exp $ */
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/*
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* Copyright (C) 1999 WIDE Project.
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* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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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/*
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* Copyright (c) 1988, 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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* @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
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*/
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#include <sys/param.h>
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#include <sys/mbuf.h>
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#include <sys/systm.h>
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#include <netinet/in.h>
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#include <netinet/ip_var.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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/*
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* Checksum routine for Internet Protocol family headers (Portable Version).
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* This is only for IPv4 pseudo header checksum.
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* No need to clear non-pseudo-header fields in IPv4 header.
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* len is for actual payload size, and does not include IPv4 header and
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* skipped header chain (off + len should be equal to the whole packet).
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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) (x > 65535 ? x -= 65535 : x)
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#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}
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int
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in4_cksum(m, nxt, off, len)
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register struct mbuf *m;
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u_int8_t nxt;
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register int off, len;
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{
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register u_int16_t *w;
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register int sum = 0;
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register int mlen = 0;
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int byte_swapped = 0;
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struct ipovly ipov;
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union {
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u_int8_t c[2];
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u_int16_t s;
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} s_util;
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union {
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u_int16_t s[2];
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u_int32_t l;
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} l_util;
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/* pseudo header */
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if (off < sizeof(struct ipovly))
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panic("offset too short");
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bzero(&ipov, sizeof(ipov));
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ipov.ih_len = htons(len);
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ipov.ih_pr = nxt;
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ipov.ih_src = mtod(m, struct ip *)->ip_src;
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ipov.ih_dst = mtod(m, struct ip *)->ip_dst;
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w = (u_int16_t *)&ipov;
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/* assumes sizeof(ipov) == 20 */
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; sum += w[4];
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sum += w[5]; sum += w[6]; sum += w[7]; sum += w[8]; sum += w[9];
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/* skip unnecessary part */
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while (m && off > 0) {
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if (m->m_len > off)
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break;
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off -= m->m_len;
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m = m->m_next;
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}
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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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w = (u_int16_t *)(mtod(m, caddr_t) + off);
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if (mlen == -1) {
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/*
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* The first byte of this mbuf is the continuation
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* of a word spanning between this mbuf and the
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* last mbuf.
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*
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* s_util.c[0] is already saved when scanning previous
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* mbuf.
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*/
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s_util.c[1] = *(u_int8_t *)w;
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sum += s_util.s;
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w = (u_int16_t *)((u_int8_t *)w + 1);
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mlen = m->m_len - off - 1;
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len--;
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} else
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mlen = m->m_len - off;
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off = 0;
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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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* Force to even boundary.
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*/
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if ((1 & (long) w) && (mlen > 0)) {
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REDUCE;
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sum <<= 8;
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s_util.c[0] = *(u_int8_t *)w;
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w = (u_int16_t *)((int8_t *)w + 1);
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mlen--;
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byte_swapped = 1;
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}
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/*
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* Unroll the loop to make overhead from
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* branches &c small.
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*/
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while ((mlen -= 32) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
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sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
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sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
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w += 16;
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}
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mlen += 32;
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while ((mlen -= 8) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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w += 4;
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}
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mlen += 8;
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if (mlen == 0 && byte_swapped == 0)
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continue;
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REDUCE;
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while ((mlen -= 2) >= 0) {
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sum += *w++;
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}
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if (byte_swapped) {
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REDUCE;
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sum <<= 8;
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byte_swapped = 0;
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if (mlen == -1) {
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s_util.c[1] = *(u_int8_t *)w;
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sum += s_util.s;
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mlen = 0;
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} else
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mlen = -1;
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} else if (mlen == -1)
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s_util.c[0] = *(u_int8_t *)w;
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}
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if (len)
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printf("cksum4: out of data\n");
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if (mlen == -1) {
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/* The last mbuf has odd # of bytes. Follow the
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standard (the odd byte may be shifted left by 8 bits
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or not as determined by endian-ness of the machine) */
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s_util.c[1] = 0;
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sum += s_util.s;
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}
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REDUCE;
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return (~sum & 0xffff);
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}
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