85 lines
2.9 KiB
C
85 lines
2.9 KiB
C
/* $NetBSD: disklabel.c,v 1.3 1994/10/26 05:44:42 cgd Exp $ */
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/*-
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* Copyright (c) 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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. 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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* @(#)disklabel.c 8.1 (Berkeley) 6/11/93
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*/
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#include <sys/param.h>
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#include <sys/disklabel.h>
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int dkcksum __P((struct disklabel *));
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char *
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getdisklabel(buf, lp)
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const char *buf;
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struct disklabel *lp;
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{
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struct disklabel *dlp, *elp;
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char *msg = (char *)0;
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elp = (struct disklabel *)(buf + DEV_BSIZE - sizeof(*dlp));
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for (dlp = (struct disklabel *)buf; dlp <= elp;
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dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
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if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
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if (msg == (char *)0)
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msg = "no disk label";
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} else if (dlp->d_npartitions > MAXPARTITIONS ||
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dkcksum(dlp) != 0)
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msg = "disk label corrupted";
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else {
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*lp = *dlp;
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msg = (char *)0;
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break;
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}
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}
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return (msg);
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}
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/*
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* Compute checksum for disk label.
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*/
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int
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dkcksum(lp)
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register struct disklabel *lp;
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{
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register u_short *start, *end;
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register u_short sum = 0;
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start = (u_short *)lp;
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end = (u_short *)&lp->d_partitions[lp->d_npartitions];
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while (start < end)
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sum ^= *start++;
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return (sum);
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}
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