xref: /netbsd-src/sys/lib/libsa/disklabel.c (revision ccb4458a63c1e73b053b6c8ff839e2081435a4d6)
1 /*	$NetBSD: disklabel.c,v 1.12 2021/05/26 04:28:15 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)disklabel.c	8.1 (Berkeley) 6/11/93
32  */
33 
34 #include <sys/param.h>
35 #include <sys/disklabel.h>
36 #include <lib/libkern/libkern.h>
37 #include "stand.h"
38 
39 
40 #if defined(LIBSA_NO_DISKLABEL_MSGS)
41 #define nolabel (char *)1
42 #define corruptedlabel (char *)1
43 #else
44 static char nolabel[] = "no disk label";
45 static char corruptedlabel[] = "disk label corrupted";
46 #endif
47 
48 char *
getdisklabel(const char * buf,struct disklabel * lp)49 getdisklabel(const char *buf, struct disklabel *lp)
50 {
51 	const struct disklabel *dlp, *elp;
52 	char *msg = NULL;
53 
54 	elp = (const void *)(buf + DEV_BSIZE - sizeof(*dlp));
55 	for (dlp = (const void *)buf; dlp <= elp;
56 	    dlp = (const void *)((const char *)dlp + sizeof(long))) {
57 #if defined(LIBSA_DISKLABEL_EI)
58 		if (dlp->d_magic == bswap32(DISKMAGIC) &&
59 		    dlp->d_magic2 == bswap32(DISKMAGIC)) {
60 			disklabel_swap(__UNCONST(dlp), __UNCONST(dlp));
61 		}
62 #endif
63 		if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
64 			if (msg == NULL)
65 				msg = nolabel;
66 		} else if (dlp->d_npartitions > MAXPARTITIONS ||
67 			   dkcksum(dlp) != 0) {
68 			msg = corruptedlabel;
69 		} else {
70 			(void)memcpy(lp, dlp, sizeof *lp);
71 			msg = NULL;
72 			break;
73 		}
74 	}
75 	return msg;
76 }
77