[apple/xnu.git] / bsd / netinet6 / in6_cksum.c

/*
 * Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

/*
 * 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.
 */

/*
 * 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
 */

/*-
 * Copyright (c) 2008 Joerg Sonnenberger <joerg@NetBSD.org>.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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.
 */

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <kern/debug.h>
#include <netinet/in.h>
#include <netinet/ip6.h>

#include <net/net_osdep.h>

#include <machine/endian.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)  do { if (x > 65535) { x -= 65535; } } while (0)
#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}

/*
 * 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)
 */

u_int16_t
inet6_cksum(struct mbuf *m, unsigned int nxt, unsigned int off,
    unsigned int len)
{
	u_int16_t *w;
	int sum = 0;
	int mlen = 0;
	int byte_swapped = 0;
	struct ip6_hdr *ip6;
	union {
		u_int16_t phs[4];
		struct {
			u_int32_t	ph_len;
			u_int8_t	ph_zero[3];
			u_int8_t	ph_nxt;
		} ph __attribute__((__packed__));
	} uph;
	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_flags & M_PKTHDR) && m->m_pkthdr.len < off + len) {
		panic("inet6_cksum: mbuf len (%d) < off+len (%d+%d)\n",
		    m->m_pkthdr.len, off, len);
	}

	if (nxt != 0) {
		bzero(&uph, sizeof (uph));

		/*
		 * 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 & (intptr_t) 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 & (intptr_t) 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)
		printf("inet6_cksum: out of data by %d\n", len);
	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);
}
Commit	Line	Data
b0d623f7 A	1	/*
	2	* Copyright (c) 2009 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
1c79356b A	28
	29	/*
	30	* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
	31	* All rights reserved.
	32	*
	33	* Redistribution and use in source and binary forms, with or without
	34	* modification, are permitted provided that the following conditions
	35	* are met:
	36	* 1. Redistributions of source code must retain the above copyright
	37	* notice, this list of conditions and the following disclaimer.
	38	* 2. Redistributions in binary form must reproduce the above copyright
	39	* notice, this list of conditions and the following disclaimer in the
	40	* documentation and/or other materials provided with the distribution.
	41	* 3. Neither the name of the project nor the names of its contributors
	42	* may be used to endorse or promote products derived from this software
	43	* without specific prior written permission.
	44	*
	45	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	46	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	47	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	48	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	49	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	50	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	51	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	52	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	53	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	54	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	55	* SUCH DAMAGE.
	56	*/
	57
	58	/*
	59	* Copyright (c) 1988, 1992, 1993
	60	* The Regents of the University of California. All rights reserved.
	61	*
	62	* Redistribution and use in source and binary forms, with or without
	63	* modification, are permitted provided that the following conditions
	64	* are met:
	65	* 1. Redistributions of source code must retain the above copyright
	66	* notice, this list of conditions and the following disclaimer.
	67	* 2. Redistributions in binary form must reproduce the above copyright
	68	* notice, this list of conditions and the following disclaimer in the
	69	* documentation and/or other materials provided with the distribution.
	70	* 3. All advertising materials mentioning features or use of this software
	71	* must display the following acknowledgement:
	72	* This product includes software developed by the University of
	73	* California, Berkeley and its contributors.
	74	* 4. Neither the name of the University nor the names of its contributors
	75	* may be used to endorse or promote products derived from this software
	76	* without specific prior written permission.
	77	*
	78	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	79	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	80	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	81	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	82	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	83	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	84	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	85	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	86	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	87	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	88	* SUCH DAMAGE.
	89	*
	90	* @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
	91	*/
92
b0d623f7 A	93	/*-
	94	* Copyright (c) 2008 Joerg Sonnenberger <joerg@NetBSD.org>.
	95	* All rights reserved.
	96	*
	97	* Redistribution and use in source and binary forms, with or without
	98	* modification, are permitted provided that the following conditions
	99	* are met:
	100	*
	101	* 1. Redistributions of source code must retain the above copyright
	102	* notice, this list of conditions and the following disclaimer.
	103	* 2. Redistributions in binary form must reproduce the above copyright
	104	* notice, this list of conditions and the following disclaimer in
	105	* the documentation and/or other materials provided with the
	106	* distribution.
	107	*
	108	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	109	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	110	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	111	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	112	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	113	* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
	114	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	115	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	116	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	117	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	118	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	119	* SUCH DAMAGE.
	120	*/
	121
1c79356b A	122	#include <sys/param.h>
	123	#include <sys/mbuf.h>
	124	#include <sys/systm.h>
2d21ac55	125	#include <kern/debug.h>
1c79356b A	126	#include <netinet/in.h>
	127	#include <netinet/ip6.h>
	128
	129	#include <net/net_osdep.h>
	130
b0d623f7 A	131	#include <machine/endian.h>
	132
	133
b0d623f7	134
1c79356b A	135	/*
	136	* Checksum routine for Internet Protocol family headers (Portable Version).
	137	*
	138	* This routine is very heavily used in the network
	139	* code and should be modified for each CPU to be as fast as possible.
	140	*/
	141
6d2010ae	142	#define ADDCARRY(x) do { if (x > 65535) { x -= 65535; } } while (0)
1c79356b A	143	#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}
1c79356b A	144
1c79356b A	145	/*
	146	* m MUST contain a continuous IP6 header.
	147	* off is a offset where TCP/UDP/ICMP6 header starts.
	148	* len is a total length of a transport segment.
	149	* (e.g. TCP header + TCP payload)
	150	*/
	151
2d21ac55 A	152	u_int16_t
	153	inet6_cksum(struct mbuf *m, unsigned int nxt, unsigned int off,
	154	unsigned int len)
1c79356b	155	{
9bccf70c A	156	u_int16_t *w;
	157	int sum = 0;
	158	int mlen = 0;
1c79356b	159	int byte_swapped = 0;
2d21ac55	160	struct ip6_hdr *ip6;
9bccf70c A	161	union {
	162	u_int16_t phs[4];
	163	struct {
	164	u_int32_t ph_len;
	165	u_int8_t ph_zero[3];
	166	u_int8_t ph_nxt;
	167	} ph __attribute__((__packed__));
	168	} uph;
1c79356b A	169	union {
	170	u_int8_t c[2];
	171	u_int16_t s;
	172	} s_util;
	173	union {
	174	u_int16_t s[2];
	175	u_int32_t l;
	176	} l_util;
	177
	178	/* sanity check */
b0d623f7	179	if ((m->m_flags & M_PKTHDR) && m->m_pkthdr.len < off + len) {
2d21ac55 A	180	panic("inet6_cksum: mbuf len (%d) < off+len (%d+%d)\n",
2d21ac55 A	181	m->m_pkthdr.len, off, len);
1c79356b A	182	}
1c79356b A	183
2d21ac55 A	184	if (nxt != 0) {
2d21ac55 A	185	bzero(&uph, sizeof (uph));
9bccf70c	186
2d21ac55 A	187	/*
	188	* First create IP6 pseudo header and calculate a summary.
	189	*/
	190	ip6 = mtod(m, struct ip6_hdr *);
	191	w = (u_int16_t *)&ip6->ip6_src;
	192	uph.ph.ph_len = htonl(len);
	193	uph.ph.ph_nxt = nxt;
1c79356b	194
2d21ac55 A	195	/* IPv6 source address */
	196	sum += w[0];
	197	if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
	198	sum += w[1];
	199	sum += w[2]; sum += w[3]; sum += w[4]; sum += w[5];
	200	sum += w[6]; sum += w[7];
	201	/* IPv6 destination address */
	202	sum += w[8];
	203	if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
	204	sum += w[9];
	205	sum += w[10]; sum += w[11]; sum += w[12]; sum += w[13];
	206	sum += w[14]; sum += w[15];
	207	/* Payload length and upper layer identifier */
	208	sum += uph.phs[0]; sum += uph.phs[1];
	209	sum += uph.phs[2]; sum += uph.phs[3];
	210	}
1c79356b	211
1c79356b A	212	/*
	213	* Secondly calculate a summary of the first mbuf excluding offset.
	214	*/
	215	while (m != NULL && off > 0) {
	216	if (m->m_len <= off)
	217	off -= m->m_len;
	218	else
	219	break;
	220	m = m->m_next;
	221	}
	222	w = (u_int16_t )(mtod(m, u_char ) + off);
	223	mlen = m->m_len - off;
	224	if (len < mlen)
	225	mlen = len;
	226	len -= mlen;
	227	/*
	228	* Force to even boundary.
	229	*/
b0d623f7	230	if ((1 & (intptr_t) w) && (mlen > 0)) {
1c79356b A	231	REDUCE;
	232	sum <<= 8;
	233	s_util.c[0] = (u_char )w;
	234	w = (u_int16_t )((char )w + 1);
	235	mlen--;
	236	byte_swapped = 1;
	237	}
	238	/*
	239	* Unroll the loop to make overhead from
	240	* branches &c small.
	241	*/
	242	while ((mlen -= 32) >= 0) {
	243	sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
	244	sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
	245	sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
	246	sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
	247	w += 16;
	248	}
	249	mlen += 32;
	250	while ((mlen -= 8) >= 0) {
	251	sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
	252	w += 4;
	253	}
	254	mlen += 8;
	255	if (mlen == 0 && byte_swapped == 0)
	256	goto next;
	257	REDUCE;
	258	while ((mlen -= 2) >= 0) {
	259	sum += *w++;
	260	}
	261	if (byte_swapped) {
	262	REDUCE;
	263	sum <<= 8;
	264	byte_swapped = 0;
	265	if (mlen == -1) {
	266	s_util.c[1] = (char )w;
	267	sum += s_util.s;
	268	mlen = 0;
	269	} else
	270	mlen = -1;
	271	} else if (mlen == -1)
	272	s_util.c[0] = (char )w;
	273	next:
	274	m = m->m_next;
	275
	276	/*
	277	* Lastly calculate a summary of the rest of mbufs.
	278	*/
2d21ac55	279
1c79356b A	280	for (;m && len; m = m->m_next) {
	281	if (m->m_len == 0)
	282	continue;
	283	w = mtod(m, u_int16_t *);
	284	if (mlen == -1) {
	285	/*
	286	* The first byte of this mbuf is the continuation
	287	* of a word spanning between this mbuf and the
	288	* last mbuf.
	289	*
	290	* s_util.c[0] is already saved when scanning previous
	291	* mbuf.
	292	*/
	293	s_util.c[1] = (char )w;
	294	sum += s_util.s;
	295	w = (u_int16_t )((char )w + 1);
	296	mlen = m->m_len - 1;
	297	len--;
	298	} else
	299	mlen = m->m_len;
	300	if (len < mlen)
	301	mlen = len;
	302	len -= mlen;
	303	/*
	304	* Force to even boundary.
	305	*/
b0d623f7	306	if ((1 & (intptr_t) w) && (mlen > 0)) {
1c79356b A	307	REDUCE;
	308	sum <<= 8;
	309	s_util.c[0] = (u_char )w;
	310	w = (u_int16_t )((char )w + 1);
	311	mlen--;
	312	byte_swapped = 1;
	313	}
	314	/*
	315	* Unroll the loop to make overhead from
	316	* branches &c small.
	317	*/
	318	while ((mlen -= 32) >= 0) {
	319	sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
	320	sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
	321	sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
	322	sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
	323	w += 16;
	324	}
	325	mlen += 32;
	326	while ((mlen -= 8) >= 0) {
	327	sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
	328	w += 4;
	329	}
	330	mlen += 8;
	331	if (mlen == 0 && byte_swapped == 0)
	332	continue;
	333	REDUCE;
	334	while ((mlen -= 2) >= 0) {
	335	sum += *w++;
	336	}
	337	if (byte_swapped) {
	338	REDUCE;
	339	sum <<= 8;
	340	byte_swapped = 0;
	341	if (mlen == -1) {
	342	s_util.c[1] = (char )w;
	343	sum += s_util.s;
	344	mlen = 0;
	345	} else
	346	mlen = -1;
	347	} else if (mlen == -1)
	348	s_util.c[0] = (char )w;
	349	}
	350	if (len)
2d21ac55	351	printf("inet6_cksum: out of data by %d\n", len);
1c79356b A	352	if (mlen == -1) {
	353	/* The last mbuf has odd # of bytes. Follow the
	354	standard (the odd byte may be shifted left by 8 bits
	355	or not as determined by endian-ness of the machine) */
	356	s_util.c[1] = 0;
	357	sum += s_util.s;
	358	}
	359	REDUCE;
	360	return (~sum & 0xffff);
	361	}
b0d623f7	362