1 /* $OpenBSD: opendev.c,v 1.8 2004/05/28 07:03:47 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 2000, Todd C. Miller. All rights reserved.
5 * Copyright (c) 1996, Jason Downs. 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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
17 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <limits.h>
32 #include <paths.h>
33 #include <stdio.h>
34 #include <string.h>
35
36 #include "util.h"
37
38 /*
39 * This routine is a generic rewrite of the original code found in
40 * disklabel(8).
41 */
42
43 int
opendev(char * path,int oflags,int dflags,char ** realpath)44 opendev(char *path, int oflags, int dflags, char **realpath)
45 {
46 static char namebuf[PATH_MAX];
47 char *slash, *prefix;
48 int fd;
49
50 /* Initial state */
51 if (realpath)
52 *realpath = path;
53 fd = -1;
54 errno = ENOENT;
55
56 if (dflags & OPENDEV_BLCK)
57 prefix = ""; /* block device */
58 else
59 prefix = "r"; /* character device */
60
61 if ((slash = strchr(path, '/')))
62 fd = open(path, oflags);
63 else if (dflags & OPENDEV_PART) {
64 /*
65 * First try raw partition (for removable drives)
66 */
67 if (snprintf(namebuf, sizeof(namebuf), "%s%s%s%c",
68 _PATH_DEV, prefix, path, 'a' + getrawpartition())
69 < sizeof(namebuf)) {
70 fd = open(namebuf, oflags);
71 if (realpath)
72 *realpath = namebuf;
73 } else
74 errno = ENAMETOOLONG;
75 }
76 if (!slash && fd == -1 && errno == ENOENT) {
77 if (snprintf(namebuf, sizeof(namebuf), "%s%s%s",
78 _PATH_DEV, prefix, path) < sizeof(namebuf)) {
79 fd = open(namebuf, oflags);
80 if (realpath)
81 *realpath = namebuf;
82 } else
83 errno = ENAMETOOLONG;
84 }
85 return (fd);
86 }
87