1/*	$NetBSD: opendir.c,v 1.38 2011/10/15 23:00:01 christos 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#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)opendir.c	8.7 (Berkeley) 12/10/94";
36#else
37__RCSID("$NetBSD: opendir.c,v 1.38 2011/10/15 23:00:01 christos Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include "namespace.h"
42#include "reentrant.h"
43#include "extern.h"
44
45#include <sys/param.h>
46#include <sys/mount.h>
47#include <sys/stat.h>
48
49#include <assert.h>
50#include <dirent.h>
51#include <errno.h>
52#include <fcntl.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56
57#include "dirent_private.h"
58
59static DIR	*__opendir_common(int, const char *, int);
60
61__weak_alias(fdopendir,_fdopendir)
62
63/*
64 * Open a directory.
65 */
66DIR *
67opendir(const char *name)
68{
69
70	_DIAGASSERT(name != NULL);
71
72	return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
73}
74
75DIR *
76__opendir2(const char *name, int flags)
77{
78	DIR *dirp;
79	int fd;
80
81	if ((fd = open(name, O_RDONLY|O_DIRECTORY|O_NONBLOCK|O_CLOEXEC)) == -1)
82		return NULL;
83
84	dirp = __opendir_common(fd, name, flags);
85	if (dirp == NULL) {
86		int serrno = errno;
87		(void)close(fd);
88		errno = serrno;
89	}
90	return dirp;
91}
92
93#ifndef __LIBC12_SOURCE__
94DIR *
95_fdopendir(int fd)
96{
97	struct stat sb;
98
99	if (fstat(fd, &sb) == -1)
100		return NULL;
101
102	if (!S_ISDIR(sb.st_mode)) {
103		errno = ENOTDIR;
104		return NULL;
105	}
106
107	/* This is optional according to POSIX, but a good measure */
108	if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
109		return NULL;
110
111	return __opendir_common(fd, NULL, DTF_HIDEW|DTF_NODUP);
112}
113#endif
114
115static DIR *
116__opendir_common(int fd, const char *name, int flags)
117{
118	DIR *dirp;
119	int serrno;
120	struct statvfs sfb;
121	int error;
122
123	if ((dirp = malloc(sizeof(*dirp))) == NULL)
124		goto error;
125	dirp->dd_buf = NULL;
126	dirp->dd_internal = NULL;
127#ifdef _REENTRANT
128	if (__isthreaded) {
129		if ((dirp->dd_lock = malloc(sizeof(mutex_t))) == NULL)
130			goto error;
131		mutex_init((mutex_t *)dirp->dd_lock, NULL);
132	}
133#endif
134
135	/*
136	 * Tweak flags for the underlying filesystem.
137	 */
138
139	if (fstatvfs1(fd, &sfb, ST_NOWAIT) < 0)
140		goto error;
141	if ((flags & DTF_NODUP) != 0) {
142		if (!strncmp(sfb.f_fstypename, MOUNT_UNION,
143		    sizeof(sfb.f_fstypename)) ||
144		    (sfb.f_flag & MNT_UNION) != 0) {
145			flags |= __DTF_READALL;
146		} else {
147			flags &= ~DTF_NODUP;
148		}
149	}
150	if (!strncmp(sfb.f_fstypename, MOUNT_NFS, sizeof(sfb.f_fstypename))) {
151		flags |= __DTF_READALL | __DTF_RETRY_ON_BADCOOKIE;
152	}
153
154	dirp->dd_flags = flags;
155	error = _initdir(dirp, fd, name);
156	if (error) {
157		errno = error;
158		goto error;
159	}
160
161	return (dirp);
162error:
163	serrno = errno;
164	if (dirp != NULL) {
165#ifdef _REENTRANT
166		if (__isthreaded) {
167			mutex_destroy((mutex_t *)dirp->dd_lock);
168			free(dirp->dd_lock);
169		}
170#endif
171		free(dirp->dd_buf);
172	}
173	free(dirp);
174	errno = serrno;
175	return NULL;
176}
177