xref: /openbsd/lib/libutil/opendisk.c (revision 5af055cd)
1 /*	$OpenBSD: opendisk.c,v 1.7 2014/06/30 00:26:22 deraadt Exp $	*/
2 /*	$NetBSD: opendisk.c,v 1.4 1997/09/30 17:13:50 phil Exp $	*/
3 
4 /*-
5  * Copyright (c) 1997 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Luke Mewburn.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <paths.h>
38 #include <stdio.h>
39 #include <string.h>
40 
41 #include "util.h"
42 
43 int
44 opendisk(const char *path, int flags, char *buf, size_t buflen, int iscooked)
45 {
46 	int f, rawpart;
47 
48 	snprintf(buf, buflen, "%s", path);
49 
50 	if ((flags & O_CREAT) != 0) {
51 		errno = EINVAL;
52 		return (-1);
53 	}
54 
55 	rawpart = getrawpartition();
56 	if (rawpart < 0)
57 		return (-1);	/* sysctl(3) in getrawpartition sets errno */
58 
59 	f = open(buf, flags);
60 	if (f != -1 || errno != ENOENT)
61 		return (f);
62 
63 	snprintf(buf, buflen, "%s%c", path, 'a' + rawpart);
64 	f = open(buf, flags);
65 	if (f != -1 || errno != ENOENT)
66 		return (f);
67 
68 	if (strchr(path, '/') != NULL)
69 		return (-1);
70 
71 	snprintf(buf, buflen, "%s%s%s", _PATH_DEV, iscooked ? "" : "r", path);
72 	f = open(buf, flags);
73 	if (f != -1 || errno != ENOENT)
74 		return (f);
75 
76 	snprintf(buf, buflen, "%s%s%s%c", _PATH_DEV, iscooked ? "" : "r", path,
77 	    'a' + rawpart);
78 	f = open(buf, flags);
79 	return (f);
80 }
81