minix/lib/libc/gen/opendir.c

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/* $NetBSD: opendir.c,v 1.38 2011/10/15 23:00:01 christos Exp $ */
/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)opendir.c 8.7 (Berkeley) 12/10/94";
#else
__RCSID("$NetBSD: opendir.c,v 1.38 2011/10/15 23:00:01 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include "reentrant.h"
#include "extern.h"
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dirent_private.h"
static DIR *__opendir_common(int, const char *, int);
__weak_alias(fdopendir,_fdopendir)
/*
* Open a directory.
*/
DIR *
opendir(const char *name)
{
_DIAGASSERT(name != NULL);
return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
}
DIR *
__opendir2(const char *name, int flags)
{
int fd;
if ((fd = open(name, O_RDONLY | O_NONBLOCK | O_CLOEXEC)) == -1)
return NULL;
return __opendir_common(fd, name, flags);
}
#ifndef __LIBC12_SOURCE__
DIR *
_fdopendir(int fd)
{
if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
return NULL;
return __opendir_common(fd, NULL, DTF_HIDEW|DTF_NODUP);
}
#endif
static DIR *
__opendir_common(int fd, const char *name, int flags)
{
DIR *dirp = NULL;
int serrno;
struct stat sb;
#if !defined(__minix)
struct statvfs sfb;
#endif /* !defined(__minix) */
int error;
if (fstat(fd, &sb) || !S_ISDIR(sb.st_mode)) {
errno = ENOTDIR;
goto error;
}
if ((dirp = malloc(sizeof(*dirp))) == NULL)
goto error;
dirp->dd_buf = NULL;
dirp->dd_internal = NULL;
#ifdef _REENTRANT
if (__isthreaded) {
if ((dirp->dd_lock = malloc(sizeof(mutex_t))) == NULL)
goto error;
mutex_init((mutex_t *)dirp->dd_lock, NULL);
}
#endif
/*
* Tweak flags for the underlying filesystem.
*/
#if defined(__minix)
/* MOUNT_UNION and MOUNT_NFS not supported */
flags &= ~DTF_NODUP;
#else
if (fstatvfs1(fd, &sfb, ST_NOWAIT) < 0)
goto error;
if ((flags & DTF_NODUP) != 0) {
if (!strncmp(sfb.f_fstypename, MOUNT_UNION,
sizeof(sfb.f_fstypename)) ||
(sfb.f_flag & MNT_UNION) != 0) {
flags |= __DTF_READALL;
} else {
flags &= ~DTF_NODUP;
}
}
if (!strncmp(sfb.f_fstypename, MOUNT_NFS, sizeof(sfb.f_fstypename))) {
flags |= __DTF_READALL | __DTF_RETRY_ON_BADCOOKIE;
}
#endif /* !defined(__minix) */
dirp->dd_flags = flags;
error = _initdir(dirp, fd, name);
if (error) {
errno = error;
goto error;
}
return (dirp);
error:
serrno = errno;
if (dirp != NULL) {
#ifdef _REENTRANT
if (__isthreaded) {
mutex_destroy((mutex_t *)dirp->dd_lock);
free(dirp->dd_lock);
}
#endif
free(dirp->dd_buf);
}
free(dirp);
if (fd != -1)
(void)close(fd);
errno = serrno;
return NULL;
}