1/*	$NetBSD: opendir.c,v 1.4 2003/08/07 09:27:58 agc Exp $	*/
2
3/*
4 * Copyright (c) 1983, 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
32#include <sys/cdefs.h>
33
34#ifdef __weak_alias
35#define opendir			_opendir
36#endif
37
38#include <sys/param.h>
39#include <sys/mount.h>
40#include <sys/stat.h>
41
42#include <dirent.h>
43#include <errno.h>
44#include <fcntl.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48
49#ifdef __weak_alias
50__weak_alias(opendir,_opendir)
51#endif
52
53/*
54 * Open a directory.
55 */
56DIR *
57opendir(name)
58	const char *name;
59{
60	DIR *dirp;
61	int fd;
62	struct stat sb;
63
64	if ((fd = open(name, O_RDONLY | O_NONBLOCK)) == -1)
65		return (NULL);
66	if (fstat(fd, &sb) || !S_ISDIR(sb.st_mode)) {
67		errno = ENOTDIR;
68		close(fd);
69		return (NULL);
70	}
71	if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
72	    (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
73		close(fd);
74		return (NULL);
75	}
76
77	/*
78	 * Determine whether this directory is the top of a union stack.
79	 * (Never is on a ramdisk)
80	 */
81	{
82		dirp->dd_len = DIRBLKSIZ;
83		dirp->dd_buf = malloc((size_t)dirp->dd_len);
84		if (dirp->dd_buf == NULL) {
85			free(dirp);
86			close (fd);
87			return (NULL);
88		}
89		dirp->dd_seek = 0;
90	}
91
92	dirp->dd_loc = 0;
93	dirp->dd_fd = fd;
94	dirp->dd_flags = DTF_HIDEW;
95
96	/*
97	 * Set up seek point for rewinddir.
98	 */
99	dirp->dd_rewind = telldir(dirp);
100
101	return (dirp);
102}
103