aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/unix/opendir.c
diff options
context:
space:
mode:
authorRoland McGrath <roland@hack.frob.com>2012-08-07 14:47:34 -0700
committerRoland McGrath <roland@hack.frob.com>2012-08-07 14:47:34 -0700
commita281decc878cf26cae12a5bdf5f4c6e0297303d6 (patch)
treeb28e5b00fdbeb4289346b0df64d6f75aaacece75 /sysdeps/unix/opendir.c
parent22895b476794b69a9a42e6bb4ceb929dc6a43917 (diff)
downloadglibc-a281decc878cf26cae12a5bdf5f4c6e0297303d6.zip
glibc-a281decc878cf26cae12a5bdf5f4c6e0297303d6.tar.gz
glibc-a281decc878cf26cae12a5bdf5f4c6e0297303d6.tar.bz2
Move common dirent implementation from sysdeps/unix to sysdeps/posix.
Diffstat (limited to 'sysdeps/unix/opendir.c')
-rw-r--r--sysdeps/unix/opendir.c228
1 files changed, 0 insertions, 228 deletions
diff --git a/sysdeps/unix/opendir.c b/sysdeps/unix/opendir.c
deleted file mode 100644
index e093142..0000000
--- a/sysdeps/unix/opendir.c
+++ /dev/null
@@ -1,228 +0,0 @@
-/* Copyright (C) 1991-1996,98,2000-2003,2005,2007,2009,2011
- Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
-
-#include <assert.h>
-#include <errno.h>
-#include <limits.h>
-#include <stddef.h>
-#include <stdlib.h>
-#include <dirent.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <string.h>
-
-#include <dirstream.h>
-#include <not-cancel.h>
-#include <kernel-features.h>
-
-
-/* opendir() must not accidentally open something other than a directory.
- Some OS's have kernel support for that, some don't. In the worst
- case we have to stat() before the open() AND fstat() after.
-
- We have to test at runtime for kernel support since libc may have
- been compiled with different headers to the kernel it's running on.
- This test can't be done reliably in the general case. We'll use
- /dev/null, which if it's not a device lots of stuff will break, as
- a guinea pig. It may be missing in chroot environments, so we
- make sure to fail safe. */
-#ifdef O_DIRECTORY
-# ifdef O_DIRECTORY_WORKS
-# define o_directory_works 1
-# define tryopen_o_directory() while (1) /* This must not be called. */
-# else
-static int o_directory_works;
-
-static void
-tryopen_o_directory (void)
-{
- int serrno = errno;
- int x = open_not_cancel_2 ("/dev/null", O_RDONLY|O_NDELAY|O_DIRECTORY);
-
- if (x >= 0)
- {
- close_not_cancel_no_status (x);
- o_directory_works = -1;
- }
- else if (errno != ENOTDIR)
- o_directory_works = -1;
- else
- o_directory_works = 1;
-
- __set_errno (serrno);
-}
-# endif
-# define EXTRA_FLAGS O_DIRECTORY
-#else
-# define EXTRA_FLAGS 0
-#endif
-
-
-DIR *
-internal_function
-__opendirat (int dfd, const char *name)
-{
- struct stat64 statbuf;
- struct stat64 *statp = NULL;
-
- if (__builtin_expect (name[0], '\1') == '\0')
- {
- /* POSIX.1-1990 says an empty name gets ENOENT;
- but `open' might like it fine. */
- __set_errno (ENOENT);
- return NULL;
- }
-
-#ifdef O_DIRECTORY
- /* Test whether O_DIRECTORY works. */
- if (o_directory_works == 0)
- tryopen_o_directory ();
-
- /* We can skip the expensive `stat' call if O_DIRECTORY works. */
- if (o_directory_works < 0)
-#endif
- {
- /* We first have to check whether the name is for a directory. We
- cannot do this after the open() call since the open/close operation
- performed on, say, a tape device might have undesirable effects. */
- if (__builtin_expect (__xstat64 (_STAT_VER, name, &statbuf), 0) < 0)
- return NULL;
- if (__builtin_expect (! S_ISDIR (statbuf.st_mode), 0))
- {
- __set_errno (ENOTDIR);
- return NULL;
- }
- }
-
- int flags = O_RDONLY|O_NDELAY|EXTRA_FLAGS|O_LARGEFILE;
-#ifdef O_CLOEXEC
- flags |= O_CLOEXEC;
-#endif
- int fd;
-#ifdef IS_IN_rtld
- assert (dfd == AT_FDCWD);
- fd = open_not_cancel_2 (name, flags);
-#else
- fd = openat_not_cancel_3 (dfd, name, flags);
-#endif
- if (__builtin_expect (fd, 0) < 0)
- return NULL;
-
-#ifdef O_DIRECTORY
- if (o_directory_works <= 0)
-#endif
- {
- /* Now make sure this really is a directory and nothing changed since
- the `stat' call. */
- if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &statbuf), 0) < 0)
- goto lose;
- if (__builtin_expect (! S_ISDIR (statbuf.st_mode), 0))
- {
- __set_errno (ENOTDIR);
- lose:
- close_not_cancel_no_status (fd);
- return NULL;
- }
- statp = &statbuf;
- }
-
- return __alloc_dir (fd, true, 0, statp);
-}
-
-
-/* Open a directory stream on NAME. */
-DIR *
-__opendir (const char *name)
-{
- return __opendirat (AT_FDCWD, name);
-}
-weak_alias (__opendir, opendir)
-
-
-#ifdef __ASSUME_O_CLOEXEC
-# define check_have_o_cloexec(fd) 1
-#else
-static int
-check_have_o_cloexec (int fd)
-{
- if (__have_o_cloexec == 0)
- __have_o_cloexec = (__fcntl (fd, F_GETFD, 0) & FD_CLOEXEC) == 0 ? -1 : 1;
- return __have_o_cloexec > 0;
-}
-#endif
-
-
-DIR *
-internal_function
-__alloc_dir (int fd, bool close_fd, int flags, const struct stat64 *statp)
-{
- /* We always have to set the close-on-exit flag if the user provided
- the file descriptor. Otherwise only if we have no working
- O_CLOEXEC support. */
-#ifdef O_CLOEXEC
- if ((! close_fd && (flags & O_CLOEXEC) == 0)
- || ! check_have_o_cloexec (fd))
-#endif
- {
- if (__builtin_expect (__fcntl (fd, F_SETFD, FD_CLOEXEC), 0) < 0)
- goto lose;
- }
-
- const size_t default_allocation = (4 * BUFSIZ < sizeof (struct dirent64)
- ? sizeof (struct dirent64) : 4 * BUFSIZ);
- const size_t small_allocation = (BUFSIZ < sizeof (struct dirent64)
- ? sizeof (struct dirent64) : BUFSIZ);
- size_t allocation = default_allocation;
-#ifdef _STATBUF_ST_BLKSIZE
- if (statp != NULL && default_allocation < statp->st_blksize)
- allocation = statp->st_blksize;
-#endif
-
- DIR *dirp = (DIR *) malloc (sizeof (DIR) + allocation);
- if (dirp == NULL)
- {
- allocation = small_allocation;
- dirp = (DIR *) malloc (sizeof (DIR) + allocation);
-
- if (dirp == NULL)
- lose:
- {
- if (close_fd)
- {
- int save_errno = errno;
- close_not_cancel_no_status (fd);
- __set_errno (save_errno);
- }
- return NULL;
- }
- }
-
- dirp->fd = fd;
-#ifndef NOT_IN_libc
- __libc_lock_init (dirp->lock);
-#endif
- dirp->allocation = allocation;
- dirp->size = 0;
- dirp->offset = 0;
- dirp->filepos = 0;
-
- return dirp;
-}