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905ae44c77
This generic implementation already expects a getdents API which is Linux specific. It also allows simplify it by assuming _DIRENT_HAVE_D_RECLEN and _DIRENT_HAVE_D_OFF support. The readdir are also expanded on each required implementation, futher fixes and improvements will make parametrize the implementation more complex. Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for all affected ABIs.
171 lines
4.3 KiB
C
171 lines
4.3 KiB
C
/* Read a directory. Linux LFS version.
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Copyright (C) 1997-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* When _DIRENT_MATCHES_DIRENT64 is defined we can alias 'readdir64' to
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'readdir'. However the function signatures are not equal due
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different return types, so we need to suppress {__}readdir so weak
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and strong alias do not throw conflicting types errors. */
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#define readdir __no_readdir_decl
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#define __readdir __no___readdir_decl
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#include <dirent.h>
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#undef __readdir
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#undef readdir
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/* Read a directory entry from DIRP. */
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struct dirent64 *
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__readdir64 (DIR *dirp)
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{
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struct dirent64 *dp;
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int saved_errno = errno;
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#if IS_IN (libc)
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__libc_lock_lock (dirp->lock);
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#endif
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do
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{
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size_t reclen;
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if (dirp->offset >= dirp->size)
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{
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/* We've emptied out our buffer. Refill it. */
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size_t maxread = dirp->allocation;
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ssize_t bytes;
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bytes = __getdents64 (dirp->fd, dirp->data, maxread);
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if (bytes <= 0)
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{
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/* On some systems getdents fails with ENOENT when the
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open directory has been rmdir'd already. POSIX.1
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requires that we treat this condition like normal EOF. */
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if (bytes < 0 && errno == ENOENT)
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bytes = 0;
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/* Don't modifiy errno when reaching EOF. */
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if (bytes == 0)
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__set_errno (saved_errno);
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dp = NULL;
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break;
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}
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dirp->size = (size_t) bytes;
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/* Reset the offset into the buffer. */
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dirp->offset = 0;
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}
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dp = (struct dirent64 *) &dirp->data[dirp->offset];
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reclen = dp->d_reclen;
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dirp->offset += reclen;
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dirp->filepos = dp->d_off;
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/* Skip deleted files. */
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} while (dp->d_ino == 0);
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#if IS_IN (libc)
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__libc_lock_unlock (dirp->lock);
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#endif
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return dp;
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}
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libc_hidden_def (__readdir64)
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#if _DIRENT_MATCHES_DIRENT64
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strong_alias (__readdir64, __readdir)
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weak_alias (__readdir64, readdir64)
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weak_alias (__readdir64, readdir)
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#else
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/* The compat code expects the 'struct direct' with d_ino being a __ino_t
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instead of __ino64_t. */
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# include <shlib-compat.h>
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# if IS_IN(rtld)
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weak_alias (__readdir64, readdir64)
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# else
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versioned_symbol (libc, __readdir64, readdir64, GLIBC_2_2);
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# endif
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# if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2)
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# include <olddirent.h>
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attribute_compat_text_section
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struct __old_dirent64 *
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__old_readdir64 (DIR *dirp)
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{
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struct __old_dirent64 *dp;
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int saved_errno = errno;
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#if IS_IN (libc)
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__libc_lock_lock (dirp->lock);
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#endif
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do
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{
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size_t reclen;
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if (dirp->offset >= dirp->size)
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{
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/* We've emptied out our buffer. Refill it. */
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size_t maxread = dirp->allocation;
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ssize_t bytes;
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bytes = __old_getdents64 (dirp->fd, dirp->data, maxread);
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if (bytes <= 0)
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{
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/* On some systems getdents fails with ENOENT when the
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open directory has been rmdir'd already. POSIX.1
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requires that we treat this condition like normal EOF. */
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if (bytes < 0 && errno == ENOENT)
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bytes = 0;
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/* Don't modifiy errno when reaching EOF. */
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if (bytes == 0)
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__set_errno (saved_errno);
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dp = NULL;
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break;
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}
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dirp->size = (size_t) bytes;
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/* Reset the offset into the buffer. */
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dirp->offset = 0;
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}
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dp = (struct __old_dirent64 *) &dirp->data[dirp->offset];
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reclen = dp->d_reclen;
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dirp->offset += reclen;
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dirp->filepos = dp->d_off;
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/* Skip deleted files. */
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} while (dp->d_ino == 0);
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#if IS_IN (libc)
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__libc_lock_unlock (dirp->lock);
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#endif
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return dp;
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}
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libc_hidden_def (__old_readdir64)
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compat_symbol (libc, __old_readdir64, readdir64, GLIBC_2_1);
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# endif /* SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2) */
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#endif /* _DIRENT_MATCHES_DIRENT64 */
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