Subversion Repositories openrisc

//==========================================================================

//

//      src/sys/netinet6/in6_cksum.c

//

//==========================================================================

//####BSDCOPYRIGHTBEGIN####

//

// -------------------------------------------

//

// Portions of this software may have been derived from OpenBSD, 

// FreeBSD or other sources, and are covered by the appropriate

// copyright disclaimers included herein.

//

// Portions created by Red Hat are

// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.

//

// -------------------------------------------

//

//####BSDCOPYRIGHTEND####

//==========================================================================

/*      $KAME: in6_cksum.c,v 1.10 2000/12/03 00:53:59 itojun Exp $      */

/*

 * 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

 */

#include <sys/param.h>

#include <sys/mbuf.h>

#include <netinet/in.h>

#include <netinet/ip6.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);}

/*

 * 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)

        struct mbuf *m;

        u_int8_t nxt;

        u_int32_t off, len;

{

        u_int16_t *w;

        int sum = 0;

        int mlen = 0;

        int byte_swapped = 0;

#if 0

        int srcifid = 0, dstifid = 0;

#endif

        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_pkthdr.len < off + len) {

                panic("in6_cksum: mbuf len (%d) < off+len (%d+%d)\n",

                        m->m_pkthdr.len, off, len);

        }

        bzero(&uph, sizeof(uph));

        /*

         * First create IP6 pseudo header and calculate a summary.

         */

        ip6 = mtod(m, struct ip6_hdr *);

#if 0

        if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {

                srcifid = ip6->ip6_src.s6_addr16[1];

                ip6->ip6_src.s6_addr16[1] = 0;

        }

        if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {

                dstifid = ip6->ip6_dst.s6_addr16[1];

                ip6->ip6_dst.s6_addr16[1] = 0;

        }

#endif

        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];

#if 0

        if (srcifid)

                ip6->ip6_src.s6_addr16[1] = srcifid;

        if (dstifid)

                ip6->ip6_dst.s6_addr16[1] = dstifid;

#endif

        /*

         * 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);

}