111 lines
4.1 KiB
C
111 lines
4.1 KiB
C
/* $NetBSD: lfs_cksum.c,v 1.27 2008/04/28 20:24:11 martin Exp $ */
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/*-
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* Copyright (c) 1999, 2000, 2001, 2002 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Konrad E. Schroder <perseant@hhhh.org>.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*-
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* Copyright (c) 1991, 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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* 3. 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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* @(#)lfs_cksum.c 8.2 (Berkeley) 10/9/94
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: lfs_cksum.c,v 1.27 2008/04/28 20:24:11 martin Exp $");
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#include <sys/param.h>
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#ifdef _KERNEL
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# include <sys/systm.h>
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# include <sys/lock.h>
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#else
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# include <stddef.h>
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#endif
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#include <sys/mount.h>
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#include <ufs/ufs/inode.h>
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#include <ufs/lfs/lfs.h>
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#include <ufs/lfs/lfs_extern.h>
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/*
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* Simple, general purpose, fast checksum. Data must be short-aligned.
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* Returns a u_long in case we ever want to do something more rigorous.
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*
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* XXX
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* Use the TCP/IP checksum instead.
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*/
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u_int32_t
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lfs_cksum_part(void *str, size_t len, u_int32_t sum)
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{
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len &= ~(sizeof(u_int16_t) - 1);
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for (; len; len -= sizeof(u_int16_t)) {
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sum ^= *(u_int16_t *)str;
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str = (void *)((u_int16_t *)str + 1);
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}
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return (sum);
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}
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u_int32_t
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cksum(void *str, size_t len)
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{
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return lfs_cksum_fold(lfs_cksum_part(str, len, 0));
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}
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u_int32_t
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lfs_sb_cksum(struct dlfs *fs)
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{
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size_t size;
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size = (size_t)offsetof(struct dlfs, dlfs_cksum);
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return cksum(fs, size);
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}
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