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-rw-r--r--sys/netinet6/in6_cksum.c301
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diff --git a/sys/netinet6/in6_cksum.c b/sys/netinet6/in6_cksum.c
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+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * 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 acknowledgement:
+ * 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
+ */
+
+#include <sys/param.h>
+#include <sys/mbuf.h>
+#include <sys/systm.h>
+#include <netinet/in.h>
+#include <netinet6/ip6.h>
+
+#include <net/net_osdep.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);}
+
+static union {
+ u_int16_t phs[4];
+ struct {
+ u_int32_t ph_len;
+ u_int8_t ph_zero[3];
+ u_int8_t ph_nxt;
+ } ph;
+} uph;
+
+/*
+ * m MUST contain a continuous IP6 header.
+ * off is a offset where TCP/UDP/ICMP6 header starts.
+ * len is a total length of a transport segment.
+ * (e.g. TCP header + TCP payload)
+ */
+
+int
+in6_cksum(m, nxt, off, len)
+ register struct mbuf *m;
+ u_int8_t nxt;
+ register int off, len;
+{
+ register u_int16_t *w;
+ register int sum = 0;
+ register int mlen = 0;
+ int byte_swapped = 0;
+ struct ip6_hdr *ip6;
+
+ union {
+ u_int8_t c[2];
+ u_int16_t s;
+ } s_util;
+ union {
+ u_int16_t s[2];
+ u_int32_t l;
+ } l_util;
+
+ /* sanity check */
+ if (m->m_pkthdr.len < off + len) {
+ panic("in6_cksum: mbuf len (%d) < off+len (%d+%d)\n",
+ m->m_pkthdr.len, off, len);
+ }
+
+ /*
+ * First create IP6 pseudo header and calculate a summary.
+ */
+ ip6 = mtod(m, struct ip6_hdr *);
+ w = (u_int16_t *)&ip6->ip6_src;
+ uph.ph.ph_len = htonl(len);
+ uph.ph.ph_nxt = nxt;
+
+ /* IPv6 source address */
+ sum += w[0];
+ if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
+ sum += w[1];
+ sum += w[2]; sum += w[3]; sum += w[4]; sum += w[5];
+ sum += w[6]; sum += w[7];
+ /* IPv6 destination address */
+ sum += w[8];
+ if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
+ sum += w[9];
+ sum += w[10]; sum += w[11]; sum += w[12]; sum += w[13];
+ sum += w[14]; sum += w[15];
+ /* Payload length and upper layer identifier */
+ sum += uph.phs[0]; sum += uph.phs[1];
+ sum += uph.phs[2]; sum += uph.phs[3];
+
+ /*
+ * Secondly calculate a summary of the first mbuf excluding offset.
+ */
+ while (m != NULL && off > 0) {
+ if (m->m_len <= off)
+ off -= m->m_len;
+ else
+ break;
+ m = m->m_next;
+ }
+ w = (u_int16_t *)(mtod(m, u_char *) + off);
+ mlen = m->m_len - off;
+ if (len < mlen)
+ mlen = len;
+ len -= mlen;
+ /*
+ * Force to even boundary.
+ */
+ if ((1 & (long) w) && (mlen > 0)) {
+ REDUCE;
+ sum <<= 8;
+ s_util.c[0] = *(u_char *)w;
+ w = (u_int16_t *)((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)
+ goto next;
+ 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;
+ next:
+ m = m->m_next;
+
+ /*
+ * Lastly calculate a summary of the rest of mbufs.
+ */
+
+ for (;m && len; m = m->m_next) {
+ if (m->m_len == 0)
+ continue;
+ w = mtod(m, u_int16_t *);
+ 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_int16_t *)((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 & (long) w) && (mlen > 0)) {
+ REDUCE;
+ sum <<= 8;
+ s_util.c[0] = *(u_char *)w;
+ w = (u_int16_t *)((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)
+ panic("in6_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);
+}
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