1 /* $NetBSD: bsdlabel.c,v 1.4 2009/03/31 11:48:15 tsutsui 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
bsd_getlabel(disk_t * dd,struct disklabel * dlp,u_int offset)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
dkcksum(struct disklabel * dl)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