d9ff82d313
Introduce a (for now copied stripped down) in6_cksum_pseudo() function. We should be able to use this from in6_cksum() but we should also ponder possible MD specific improvements. It takes an extra csum argument to allow for easy checks as will be done by the upper layer protocol input paths. Sponsored by: The FreeBSD Foundation Sponsored by: iXsystems Reviewed by: gnn (as part of the whole) MFC After: 3 days
358 lines
9.7 KiB
C
358 lines
9.7 KiB
C
/*-
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* Copyright (C) 1995, 1996, 1997, and 1998 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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* $KAME: in6_cksum.c,v 1.10 2000/12/03 00:53:59 itojun Exp $
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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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* 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/cdefs.h>
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__FBSDID("$FreeBSD$");
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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/ip6.h>
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#include <netinet6/scope6_var.h>
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/*
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* Checksum routine for Internet Protocol family headers (Portable Version).
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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]; (void)ADDCARRY(sum);}
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static int
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_in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
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{
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int sum;
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uint16_t scope, *w;
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union {
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u_int16_t phs[4];
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struct {
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u_int32_t ph_len;
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u_int8_t ph_zero[3];
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u_int8_t ph_nxt;
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} __packed ph;
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} uph;
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sum = csum;
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/*
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* First create IP6 pseudo header and calculate a summary.
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*/
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uph.ph.ph_len = htonl(len);
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uph.ph.ph_zero[0] = uph.ph.ph_zero[1] = uph.ph.ph_zero[2] = 0;
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uph.ph.ph_nxt = nxt;
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/* Payload length and upper layer identifier. */
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sum += uph.phs[0]; sum += uph.phs[1];
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sum += uph.phs[2]; sum += uph.phs[3];
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/* IPv6 source address. */
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scope = in6_getscope(&ip6->ip6_src);
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w = (u_int16_t *)&ip6->ip6_src;
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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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if (scope != 0)
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sum -= scope;
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/* IPv6 destination address. */
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scope = in6_getscope(&ip6->ip6_dst);
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w = (u_int16_t *)&ip6->ip6_dst;
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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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if (scope != 0)
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sum -= scope;
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return (sum);
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}
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int
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in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
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{
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int sum;
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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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sum = _in6_cksum_pseudo(ip6, len, nxt, csum);
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REDUCE;
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return (sum);
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}
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/*
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* m MUST contain a contiguous IP6 header.
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* off is an offset where TCP/UDP/ICMP6 header starts.
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* len is a total length of a transport segment.
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* (e.g. TCP header + TCP payload)
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*/
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int
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in6_cksum(struct mbuf *m, u_int8_t nxt, u_int32_t off, u_int32_t len)
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{
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struct ip6_hdr *ip6;
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u_int16_t *w, scope;
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int byte_swapped, mlen;
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int sum;
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union {
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u_int16_t phs[4];
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struct {
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u_int32_t ph_len;
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u_int8_t ph_zero[3];
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u_int8_t ph_nxt;
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} __packed ph;
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} uph;
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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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/* Sanity check. */
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KASSERT(m->m_pkthdr.len >= off + len, ("%s: mbuf len (%d) < off(%d)+"
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"len(%d)", __func__, m->m_pkthdr.len, off, len));
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/*
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* First create IP6 pseudo header and calculate a summary.
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*/
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uph.ph.ph_len = htonl(len);
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uph.ph.ph_zero[0] = uph.ph.ph_zero[1] = uph.ph.ph_zero[2] = 0;
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uph.ph.ph_nxt = nxt;
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/* Payload length and upper layer identifier. */
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sum = uph.phs[0]; sum += uph.phs[1];
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sum += uph.phs[2]; sum += uph.phs[3];
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ip6 = mtod(m, struct ip6_hdr *);
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/* IPv6 source address. */
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scope = in6_getscope(&ip6->ip6_src);
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w = (u_int16_t *)&ip6->ip6_src;
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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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if (scope != 0)
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sum -= scope;
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/* IPv6 destination address. */
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scope = in6_getscope(&ip6->ip6_dst);
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w = (u_int16_t *)&ip6->ip6_dst;
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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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if (scope != 0)
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sum -= scope;
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/*
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* Secondly calculate a summary of the first mbuf excluding offset.
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*/
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while (off > 0) {
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if (m->m_len <= off)
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off -= m->m_len;
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else
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break;
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m = m->m_next;
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}
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w = (u_int16_t *)(mtod(m, u_char *) + off);
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mlen = m->m_len - off;
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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_char *)w;
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w = (u_int16_t *)((char *)w + 1);
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mlen--;
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byte_swapped = 1;
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} else
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byte_swapped = 0;
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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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goto next;
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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] = *(char *)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] = *(char *)w;
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next:
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m = m->m_next;
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/*
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* Lastly calculate a summary of the rest of mbufs.
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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 = mtod(m, u_int16_t *);
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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] = *(char *)w;
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sum += s_util.s;
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w = (u_int16_t *)((char *)w + 1);
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mlen = m->m_len - 1;
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len--;
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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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* 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_char *)w;
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w = (u_int16_t *)((char *)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] = *(char *)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] = *(char *)w;
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}
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if (len)
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panic("in6_cksum: out of data");
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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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