lib/libc/gen/opendir.c

   1 /*      $NetBSD: opendir.c,v 1.37 2010/09/26 02:26:59 yamt 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
  35 static char sccsid[] = "@(#)opendir.c   8.7 (Berkeley) 12/10/94";
  36 #else
  37 __RCSID("$NetBSD: opendir.c,v 1.37 2010/09/26 02:26:59 yamt Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include "reentrant.h"
  43
  44 #ifdef __minix
  45 #include <sys/cdefs.h>
  46 #include <sys/types.h>
  47 #endif
  48
  49 #include "extern.h"
  50
  51 #include <sys/param.h>
  52 #include <sys/mount.h>
  53 #include <sys/stat.h>
  54
  55 #include <assert.h>
  56 #include <dirent.h>
  57 #include <errno.h>
  58 #include <fcntl.h>
  59 #include <stdlib.h>
  60 #include <string.h>
  61 #include <unistd.h>
  62
  63 #include "dirent_private.h"
  64
  65 static DIR      *__opendir_common(int, const char *, int);
  66
  67 __weak_alias(fdopendir,_fdopendir)
  68
  69 /*
  70  * Open a directory.
  71  */
  72 DIR *
  73 opendir(const char *name)
  74 {
  75
  76         _DIAGASSERT(name != NULL);
  77
  78         return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
  79 }
  80
  81 DIR *
  82 __opendir2(const char *name, int flags)
  83 {
  84         int fd;
  85
  86         if ((fd = open(name, O_RDONLY | O_NONBLOCK)) == -1)
  87                 return NULL;
  88         return __opendir_common(fd, name, flags);
  89 }
  90
  91 #ifndef __LIBC12_SOURCE__
  92 DIR *
  93 _fdopendir(int fd)
  94 {
  95
  96         return __opendir_common(fd, NULL, DTF_HIDEW|DTF_NODUP);
  97 }
  98 #endif
  99
 100 static DIR *
 101 __opendir_common(int fd, const char *name, int flags)
 102 {
 103         DIR *dirp = NULL;
 104         int serrno;
 105         struct stat sb;
 106 #ifndef __minix
 107         struct statvfs sfb;
 108 #endif
 109         int error;
 110
 111         if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
 112                 goto error;
 113         if (fstat(fd, &sb) || !S_ISDIR(sb.st_mode)) {
 114                 errno = ENOTDIR;
 115                 goto error;
 116         }
 117         if ((dirp = (DIR *)malloc(sizeof(DIR))) == NULL)
 118                 goto error;
 119         dirp->dd_buf = NULL;
 120         dirp->dd_internal = NULL;
 121 #ifdef _REENTRANT
 122         if (__isthreaded) {
 123                 if ((dirp->dd_lock = malloc(sizeof(mutex_t))) == NULL)
 124                         goto error;
 125                 mutex_init((mutex_t *)dirp->dd_lock, NULL);
 126         }
 127 #endif
 128
 129         /*
 130          * Tweak flags for the underlying filesystem.
 131          */
 132
 133 #ifdef __minix
 134         /* MOUNT_UNION and MOUNT_NFS not supported */
 135         flags &= ~DTF_NODUP;
 136 #else
 137         if (fstatvfs1(fd, &sfb, ST_NOWAIT) < 0)
 138                 goto error;
 139         if ((flags & DTF_NODUP) != 0) {
 140                 if (!strncmp(sfb.f_fstypename, MOUNT_UNION,
 141                     sizeof(sfb.f_fstypename)) ||
 142                     (sfb.f_flag & MNT_UNION) != 0) {
 143                         flags |= __DTF_READALL;
 144                 } else {
 145                         flags &= ~DTF_NODUP;
 146                 }
 147         }
 148         if (!strncmp(sfb.f_fstypename, MOUNT_NFS, sizeof(sfb.f_fstypename))) {
 149                 flags |= __DTF_READALL | __DTF_RETRY_ON_BADCOOKIE;
 150         }
 151 #endif
 152
 153         dirp->dd_flags = flags;
 154         error = _initdir(dirp, fd, name);
 155         if (error) {
 156                 errno = error;
 157                 goto error;
 158         }
 159
 160         return (dirp);
 161 error:
 162         serrno = errno;
 163         if (dirp != NULL) {
 164 #ifdef _REENTRANT
 165                 if (__isthreaded) {
 166                         mutex_destroy((mutex_t *)dirp->dd_lock);
 167                         free(dirp->dd_lock);
 168                 }
 169 #endif
 170                 free(dirp->dd_buf);
 171         }
 172         free(dirp);
 173         if (fd != -1)
 174                 (void)close(fd);
 175         errno = serrno;
 176         return NULL;
 177 }