xref: /netbsd/lib/libutil/disklabel_scan.c (revision c4a72b64)
1 /* $NetBSD: disklabel_scan.c,v 1.1 2002/10/12 20:53:15 elric Exp $ */
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Roland C. Dowdeswell.
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 <sys/cdefs.h>
40 #ifndef lint
41 __COPYRIGHT(
42 "@(#) Copyright (c) 2002\
43 	The NetBSD Foundation, Inc.  All rights reserved.");
44 __RCSID("$NetBSD: disklabel_scan.c,v 1.1 2002/10/12 20:53:15 elric Exp $");
45 #endif
46 
47 #include <string.h>
48 #include <unistd.h>
49 #include <util.h>
50 
51 #include <sys/disklabel.h>
52 
53 #define SCAN_INCR	4
54 
55 int
56 disklabel_scan(struct disklabel *lp, char *buf, size_t buflen)
57 {
58 	int	i;
59 
60 	/* scan for the correct magic numbers. */
61 
62 	for (i=0; i <= buflen - sizeof(*lp); i += SCAN_INCR) {
63 		memcpy(lp, buf + i, sizeof(*lp));
64 		if (lp->d_magic == DISKMAGIC && lp->d_magic2 == DISKMAGIC)
65 			goto sanity;
66 	}
67 
68 	return 1;
69 
70 sanity:
71 	/* we've found something, let's sanity check it */
72 	if (lp->d_npartitions > MAXPARTITIONS || disklabel_dkcksum(lp))
73 		return 1;
74 
75 	return 0;
76 }
77