support: Add <support/xdirent.h>

Use static functions for readdir/readdir_r, so that
-D_FILE_OFFSET_BITS=64 does not improperly redirect calls to the wrong
implementation.

Reviewed-by: DJ Delorie <dj@redhat.com>
This commit is contained in:
Florian Weimer 2024-08-30 21:52:10 +02:00
parent b09a520bb6
commit 3b1d321776
8 changed files with 321 additions and 0 deletions

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@ -77,6 +77,8 @@ libsupport-routines = \
support_quote_blob \
support_quote_blob_wide \
support_quote_string \
support_readdir_check \
support_readdir_r_check \
support_record_failure \
support_run_diff \
support_select_modifies_timeout \
@ -119,6 +121,7 @@ libsupport-routines = \
xclock_settime_time64 \
xclone \
xclose \
xclosedir \
xconnect \
xcopy_file_range \
xdlfcn \
@ -126,6 +129,7 @@ libsupport-routines = \
xdup2 \
xfchmod \
xfclose \
xfdopendir \
xfgets \
xfopen \
xfork \
@ -147,6 +151,7 @@ libsupport-routines = \
xmunmap \
xnewlocale \
xopen \
xopendir \
xpipe \
xpoll \
xposix_memalign \
@ -331,6 +336,7 @@ tests = \
tst-test_compare_string \
tst-test_compare_string_wide \
tst-timespec \
tst-xdirent \
tst-xreadlink \
tst-xsigstack \
# tests

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@ -0,0 +1,30 @@
/* Error-checking helper for xreaddir, xreaddir64.
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#include <support/xdirent.h>
#include <support/check.h>
void *
support_readdir_check (const char *name, void *result, int saved_errno)
{
if (result == NULL && errno != 0)
FAIL_EXIT1 ("%s: %m", name);
errno = saved_errno;
return result;
}

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@ -0,0 +1,35 @@
/* Error-checking helper for xreaddir_r, xreaddir64_r.
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#include <support/xdirent.h>
#include <support/check.h>
int
support_readdir_r_check (const char *name, int result, void *buf, void *ptr)
{
if (result != 0)
{
errno = result;
FAIL_EXIT1 ("%s: %m", name);
}
if (buf != ptr)
FAIL_EXIT1 ("%s: buffer pointer and returned pointer differ: %p != %p",
name, buf, ptr);
return result;
}

76
support/tst-xdirent.c Normal file
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@ -0,0 +1,76 @@
/* Compile test for error-checking wrappers for <dirent.h>
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#include <support/xdirent.h>
#include <libc-diag.h>
#include <support/check.h>
#include <unistd.h>
static int
do_test (void)
{
{
DIR *d = xopendir (".");
struct dirent *e = xreaddir (d);
/* Assume that the "." special entry always comes first. */
TEST_COMPARE_STRING (e->d_name, ".");
while (xreaddir (d) != NULL)
;
xclosedir (d);
}
{
DIR *d = xopendir (".");
struct dirent64 *e = xreaddir64 (d);
TEST_COMPARE_STRING (e->d_name, ".");
while (xreaddir64 (d) != NULL)
;
xclosedir (d);
}
/* The functions readdir_r, readdir64_r were deprecated in glibc 2.24. */
DIAG_PUSH_NEEDS_COMMENT;
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
{
DIR *d = xopendir (".");
struct dirent buf = { 0, };
TEST_VERIFY (xreaddir_r (d, &buf));
TEST_COMPARE_STRING (buf.d_name, ".");
while (xreaddir_r (d, &buf))
;
xclosedir (d);
}
{
DIR *d = xopendir (".");
struct dirent64 buf = { 0, };
TEST_VERIFY (xreaddir64_r (d, &buf));
TEST_COMPARE_STRING (buf.d_name, ".");
while (xreaddir64_r (d, &buf))
;
xclosedir (d);
}
DIAG_POP_NEEDS_COMMENT;
return 0;
}
#include <support/test-driver.c>

28
support/xclosedir.c Normal file
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@ -0,0 +1,28 @@
/* Error-checking wrapper for closedir.
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#include <support/xdirent.h>
#include <support/check.h>
void
xclosedir (DIR *dir)
{
if (closedir (dir) != 0)
FAIL_EXIT1 ("closedir: %m");
}

86
support/xdirent.h Normal file
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@ -0,0 +1,86 @@
/* Error-checking wrappers for <dirent.h>
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#ifndef SUPPORT_XDIRENT_H
#define SUPPORT_XDIRENT_H
#include <dirent.h>
#include <errno.h>
#include <libc-diag.h>
#include <stdbool.h>
#include <stddef.h>
__BEGIN_DECLS
DIR *xopendir (const char *path);
DIR *xfdopendir (int fd);
void xclosedir (DIR *);
void *support_readdir_check (const char *, void *, int);
static __attribute__ ((unused)) struct dirent *
xreaddir (DIR *stream)
{
int saved_errno = errno;
errno = 0;
struct dirent *result = readdir (stream);
return support_readdir_check ("readdir", result, saved_errno);
}
static __attribute__ ((unused)) struct dirent64 *
xreaddir64 (DIR *stream)
{
int saved_errno = errno;
errno = 0;
struct dirent64 *result = readdir64 (stream);
return support_readdir_check ("readdir64", result, saved_errno);
}
/* The functions readdir_r, readdir64_r were deprecated in glibc 2.24. */
DIAG_PUSH_NEEDS_COMMENT;
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
int support_readdir_r_check (const char *, int, void *, void *);
static __attribute__ ((unused)) bool
xreaddir_r (DIR *stream, struct dirent *buf)
{
struct dirent *ptr;
int ret = readdir_r (stream, buf, &ptr);
if (ret == 0 && ptr == NULL)
return false;
support_readdir_r_check ("readdir_r", ret, buf, ptr);
return true;
}
static __attribute__ ((unused)) bool
xreaddir64_r (DIR *stream, struct dirent64 *buf)
{
struct dirent64 *ptr;
int ret = readdir64_r (stream, buf, &ptr);
if (ret == 0 && ptr == NULL)
return false;
support_readdir_r_check ("readdir64_r", ret, buf, ptr);
return true;
}
DIAG_POP_NEEDS_COMMENT;
__END_DECLS
#endif /* SUPPORT_XDIRENT_H */

30
support/xfdopendir.c Normal file
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@ -0,0 +1,30 @@
/* Error-checking wrapper for fdopendir.
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#include <support/xdirent.h>
#include <support/check.h>
DIR *
xfdopendir (int fd)
{
DIR *result = fdopendir (fd);
if (result == NULL)
FAIL_EXIT1 ("fdopendir (%d): %m", fd);
return result;
}

30
support/xopendir.c Normal file
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@ -0,0 +1,30 @@
/* Error-checking wrapper for opendir.
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#include <support/xdirent.h>
#include <support/check.h>
DIR *
xopendir (const char *path)
{
DIR *result = opendir (path);
if (result == NULL)
FAIL_EXIT1 ("opendir (\"%s\"): %m", path);
return result;
}