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author | Roland McGrath <roland@hack.frob.com> | 2012-08-07 14:47:34 -0700 |
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committer | Roland McGrath <roland@hack.frob.com> | 2012-08-07 14:47:34 -0700 |
commit | a281decc878cf26cae12a5bdf5f4c6e0297303d6 (patch) | |
tree | b28e5b00fdbeb4289346b0df64d6f75aaacece75 /sysdeps/unix/opendir.c | |
parent | 22895b476794b69a9a42e6bb4ceb929dc6a43917 (diff) | |
download | glibc-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.c | 228 |
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; -} |