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bsdlabel.c revision 1.1.120.1 
      1 /*	$NetBSD: bsdlabel.c,v 1.1.120.1 2009/05/04 08:10:50 yamt Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995 Waldi Ravens.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *        This product includes software developed by Waldi Ravens.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/types.h>
     34 #include <stdlib.h>
     35 #include <stdio.h>
     36 #include <string.h>
     37 #include "libtos.h"
     38 #include "diskio.h"
     39 #include "ahdilbl.h"
     40 #include "disklbl.h"
     41 
     42 static int	dkcksum    PROTO((struct disklabel *));
     43 
     44 int
     45 bsd_getlabel(disk_t *dd, struct disklabel *dlp, u_int offset)
     46 {
     47 	u_char		*bblk;
     48 	u_int		nsec;
     49 	int		rv;
     50 
     51 	nsec = (BBMINSIZE + (dd->bsize - 1)) / dd->bsize;
     52 	bblk = disk_read(dd, offset, nsec);
     53 	if (bblk) {
     54 		u_int	*end, *p;
     55 
     56 		end = (u_int *)&bblk[BBMINSIZE - sizeof(struct disklabel)];
     57 		rv  = 1;
     58 		for (p = (u_int *)bblk; p < end; ++p) {
     59 			struct disklabel *dl = (struct disklabel *)&p[1];
     60 			if (  (  (p[0] == NBDAMAGIC && offset == 0)
     61 			      || (p[0] == AHDIMAGIC && offset != 0)
     62 			      || (u_char *)dl - bblk == 7168
     63 			      )
     64 			   && dl->d_npartitions <= MAXPARTITIONS
     65 			   && dl->d_magic2 == DISKMAGIC
     66 			   && dl->d_magic  == DISKMAGIC
     67 			   && dkcksum(dl)  == 0
     68 			   )	{
     69 				memcpy(dlp, dl, sizeof(*dlp));
     70 				rv = 0;
     71 				break;
     72 			}
     73 		}
     74 		free(bblk);
     75 	}
     76 	else rv = -1;
     77 
     78 	return(rv);
     79 }
     80 
     81 static int
     82 dkcksum(struct disklabel *dl)
     83 {
     84 	u_short	*start, *end, sum = 0;
     85 
     86 	start = (u_short *)dl;
     87 	end   = (u_short *)&dl->d_partitions[dl->d_npartitions];
     88 	while (start < end)
     89 		sum ^= *start++;
     90 	return(sum);
     91 }
     92