xref: /netbsd-src/lib/libutil/opendisk.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: opendisk.c,v 1.10 2008/04/28 20:23:03 martin Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Luke Mewburn.
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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: opendisk.c,v 1.10 2008/04/28 20:23:03 martin Exp $");
35 #endif
36 
37 #include <sys/param.h>
38 
39 #include <assert.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <util.h>
43 #include <paths.h>
44 #include <stdio.h>
45 #include <string.h>
46 
47 int
48 opendisk(const char *path, int flags, char *buf, size_t buflen, int iscooked)
49 {
50 	int f, rawpart;
51 
52 	if (buf == NULL) {
53 		errno = EFAULT;
54 		return (-1);
55 	}
56 	snprintf(buf, buflen, "%s", path);
57 
58 	if ((flags & O_CREAT) != 0) {
59 		errno = EINVAL;
60 		return (-1);
61 	}
62 
63 	rawpart = getrawpartition();
64 	if (rawpart < 0)
65 		return (-1);	/* sysctl(3) in getrawpartition sets errno */
66 
67 	f = open(buf, flags);
68 	if (f != -1 || errno != ENOENT)
69 		return (f);
70 
71 	snprintf(buf, buflen, "%s%c", path, 'a' + rawpart);
72 	f = open(buf, flags);
73 	if (f != -1 || errno != ENOENT)
74 		return (f);
75 
76 	if (strchr(path, '/') != NULL)
77 		return (-1);
78 
79 	snprintf(buf, buflen, "%s%s%s", _PATH_DEV, iscooked ? "" : "r", path);
80 	f = open(buf, flags);
81 	if (f != -1 || errno != ENOENT)
82 		return (f);
83 
84 	snprintf(buf, buflen, "%s%s%s%c", _PATH_DEV, iscooked ? "" : "r", path,
85 	    'a' + rawpart);
86 	f = open(buf, flags);
87 	return (f);
88 }
89