/* much like chdir(2), but safer
- Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2005-2006, 2008-2010 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* written by Jim Meyering */
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
#include "chdir-safer.h"
#include <sys/stat.h>
#include "same-inode.h"
+#ifndef HAVE_READLINK
+# define HAVE_READLINK 0
+#endif
+
/* Like chdir, but fail if DIR is a symbolic link to a directory (or
similar funny business), or if DIR is not readable. This avoids a
minor race condition between when a directory is created or statted
int result = 0;
int saved_errno;
int fd = open (dir,
- O_RDONLY | O_DIRECTORY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK);
+ O_RDONLY | O_DIRECTORY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK);
if (fd < 0)
return -1;
/* If open follows symlinks, lstat DIR and fstat FD to ensure that
they are the same file; if they are different files, set errno to
ELOOP (the same value that open uses for symlinks with
- O_NOFOLLOW) so the caller can report a failure. */
- if (! O_NOFOLLOW)
+ O_NOFOLLOW) so the caller can report a failure.
+ Skip this check if HAVE_READLINK == 0, which should be the case
+ on any system that lacks symlink support. */
+ if (HAVE_READLINK && ! HAVE_WORKING_O_NOFOLLOW)
{
struct stat sb1;
result = lstat (dir, &sb1);
if (result == 0)
- {
- struct stat sb2;
- result = fstat (fd, &sb2);
- if (result == 0 && ! SAME_INODE (sb1, sb2))
- {
- errno = ELOOP;
- result = -1;
- }
- }
+ {
+ struct stat sb2;
+ result = fstat (fd, &sb2);
+ if (result == 0 && ! SAME_INODE (sb1, sb2))
+ {
+ errno = ELOOP;
+ result = -1;
+ }
+ }
}
if (result == 0)