xref: /netbsd/sys/arch/atari/stand/ahdilabel/magic.c (revision bf9ec67e)
1 /*	$NetBSD: magic.c,v 1.1.1.1 2000/08/07 09:23:40 leo Exp $	*/
2 
3 /*
4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Julian Coleman, Waldi Ravens and Leo Weppelman.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include "privahdi.h"
40 #include <stdlib.h>
41 
42 /*
43  * Check label magic numbers for AHDI partitions
44  */
45 int
46 check_magic(fd, offset, flags)
47 	int			 fd;
48 	u_int			 offset;
49 	int			 flags;
50 {
51 	u_char	*bblk;
52 	u_int	 nsec;
53 	int	 rv = 1;
54 
55 	nsec = (BBMINSIZE + (DEV_BSIZE - 1)) / DEV_BSIZE;
56 	bblk = disk_read(fd, offset, nsec);
57 	if (bblk != NULL) {
58 		u_int	*end, *p;
59 
60 		end = (u_int *)&bblk[BBMINSIZE - sizeof(struct disklabel)];
61 		for (p = (u_int *)bblk; p < end; ++p) {
62 			struct disklabel *dl = (struct disklabel *)&p[1];
63 			if (((p[0] == NBDAMAGIC && offset == 0 &&
64 			    !(flags & FORCE_AHDI)) ||
65 			    (p[0] == AHDIMAGIC && offset != 0) ||
66 			    (u_char *)dl - bblk == 7168) &&
67 			    dl->d_npartitions <= MAXPARTITIONS &&
68 			    dl->d_magic2 == DISKMAGIC &&
69 			    dl->d_magic  == DISKMAGIC &&
70 			    dkcksum(dl)  == 0) {
71 				rv = -3;
72 				break;
73 			}
74 		}
75 		free(bblk);
76 	}
77 	else
78 		rv = -1;
79 
80 	return (rv);
81 }
82