SLiRP overhaul
This commit is contained in:
@@ -1,3 +1,4 @@
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/* SPDX-License-Identifier: BSD-3-Clause */
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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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@@ -37,101 +38,142 @@
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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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* XXX Since we will never span more than 1 SLIRPmbuf, we can optimise this
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*
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* XXX Since we will never span more than 1 mbuf, we can optimise this
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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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#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
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#define REDUCE \
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{ \
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l_util.l = sum; \
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sum = l_util.s[0] + l_util.s[1]; \
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(void)ADDCARRY(sum); \
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}
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int cksum(struct SLIRPmbuf *m, int len)
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int cksum(struct mbuf *m, int 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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register uint16_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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union {
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uint8_t c[2];
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uint16_t s;
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} s_util;
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union {
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uint16_t s[2];
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uint32_t l;
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} l_util;
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if (m->m_len == 0)
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goto cont;
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w = mtod(m, uint16_t *);
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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 & (uintptr_t)w) && (mlen > 0)) {
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REDUCE;
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sum <<= 8;
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s_util.c[0] = *(uint8_t *)w;
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w = (uint16_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];
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sum += w[1];
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sum += w[2];
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sum += w[3];
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sum += w[4];
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sum += w[5];
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sum += w[6];
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sum += w[7];
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sum += w[8];
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sum += w[9];
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sum += w[10];
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sum += w[11];
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sum += w[12];
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sum += w[13];
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sum += w[14];
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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];
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sum += w[1];
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sum += w[2];
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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 cont;
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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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if (mlen == -1) {
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s_util.c[1] = *(uint8_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] = *(uint8_t *)w;
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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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if (m->m_len == 0)
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goto cont;
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w = mtod(m, u_int16_t *);
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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 & (intptr_t) 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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goto cont;
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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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cont:
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#ifdef SLIRP_DEBUG
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if (len) {
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DEBUG_ERROR((dfd, "cksum: out of data\n"));
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DEBUG_ERROR((dfd, " len = %d\n", len));
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}
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#endif
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if (mlen == -1) {
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/* The last SLIRPmbuf 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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if (len) {
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DEBUG_ERROR("cksum: out of data");
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DEBUG_ERROR(" len = %d", len);
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}
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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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int ip6_cksum(struct mbuf *m)
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{
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/* TODO: Optimize this by being able to pass the ip6_pseudohdr to cksum
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* separately from the mbuf */
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struct ip6 save_ip, *ip = mtod(m, struct ip6 *);
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struct ip6_pseudohdr *ih = mtod(m, struct ip6_pseudohdr *);
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int sum;
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save_ip = *ip;
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ih->ih_src = save_ip.ip_src;
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ih->ih_dst = save_ip.ip_dst;
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ih->ih_pl = htonl((uint32_t)ntohs(save_ip.ip_pl));
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ih->ih_zero_hi = 0;
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ih->ih_zero_lo = 0;
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ih->ih_nh = save_ip.ip_nh;
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sum = cksum(m, ((int)sizeof(struct ip6_pseudohdr)) + ntohl(ih->ih_pl));
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*ip = save_ip;
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return sum;
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}
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