-/* Define an at-style functions like fstatat, unlinkat, fchownat, etc.
- Copyright (C) 2006 Free Software Foundation, Inc.
+/* Define at-style functions like fstatat, unlinkat, fchownat, etc.
+ Copyright (C) 2006, 2009-2013 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 */
-#define CALL_FUNC(F) \
- (AT_FUNC_USE_F1_COND \
- ? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS) \
+#include "dosname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
+
+#ifdef GNULIB_SUPPORT_ONLY_AT_FDCWD
+# include <errno.h>
+# ifndef ENOTSUP
+# define ENOTSUP EINVAL
+# endif
+#else
+# include "openat.h"
+# include "openat-priv.h"
+# include "save-cwd.h"
+#endif
+
+#ifdef AT_FUNC_USE_F1_COND
+# define CALL_FUNC(F) \
+ (flag == AT_FUNC_USE_F1_COND \
+ ? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS) \
: AT_FUNC_F2 (F AT_FUNC_POST_FILE_ARGS))
+# define VALIDATE_FLAG(F) \
+ if (flag & ~AT_FUNC_USE_F1_COND) \
+ { \
+ errno = EINVAL; \
+ return FUNC_FAIL; \
+ }
+#else
+# define CALL_FUNC(F) (AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS))
+# define VALIDATE_FLAG(F) /* empty */
+#endif
+
+#ifdef AT_FUNC_RESULT
+# define FUNC_RESULT AT_FUNC_RESULT
+#else
+# define FUNC_RESULT int
+#endif
-/* Call AT_FUNC_F1 or AT_FUNC_F2 (testing AT_FUNC_USE_F1_COND to
- determine which) to operate on FILE, which is in the directory
- open on descriptor FD. If possible, do it without changing the
+#ifdef AT_FUNC_FAIL
+# define FUNC_FAIL AT_FUNC_FAIL
+#else
+# define FUNC_FAIL -1
+#endif
+
+/* Call AT_FUNC_F1 to operate on FILE, which is in the directory
+ open on descriptor FD. If AT_FUNC_USE_F1_COND is defined to a value,
+ AT_FUNC_POST_FILE_PARAM_DECLS must include a parameter named flag;
+ call AT_FUNC_F2 if FLAG is 0 or fail if FLAG contains more bits than
+ AT_FUNC_USE_F1_COND. Return int and fail with -1 unless AT_FUNC_RESULT
+ or AT_FUNC_FAIL are defined. If possible, do it without changing the
working directory. Otherwise, resort to using save_cwd/fchdir,
then AT_FUNC_F?/restore_cwd. If either the save_cwd or the restore_cwd
fails, then give a diagnostic and exit nonzero. */
-int
+FUNC_RESULT
AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS)
{
- struct saved_cwd saved_cwd;
- int saved_errno;
- int err;
+ VALIDATE_FLAG (flag);
if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file))
return CALL_FUNC (file);
+#ifdef GNULIB_SUPPORT_ONLY_AT_FDCWD
+ errno = ENOTSUP;
+ return FUNC_FAIL;
+#else
{
- char buf[OPENAT_BUFFER_SIZE];
- char *proc_file = openat_proc_name (buf, fd, file);
+ /* Be careful to choose names unlikely to conflict with
+ AT_FUNC_POST_FILE_PARAM_DECLS. */
+ struct saved_cwd saved_cwd;
+ int saved_errno;
+ FUNC_RESULT err;
+
+ {
+ char proc_buf[OPENAT_BUFFER_SIZE];
+ char *proc_file = openat_proc_name (proc_buf, fd, file);
if (proc_file)
{
- int proc_result = CALL_FUNC (proc_file);
- int proc_errno = errno;
- if (proc_file != buf)
- free (proc_file);
- /* If the syscall succeeds, or if it fails with an unexpected
- errno value, then return right away. Otherwise, fall through
- and resort to using save_cwd/restore_cwd. */
- if (0 <= proc_result)
- return proc_result;
- if (! EXPECTED_ERRNO (proc_errno))
- {
- errno = proc_errno;
- return proc_result;
- }
+ FUNC_RESULT proc_result = CALL_FUNC (proc_file);
+ int proc_errno = errno;
+ if (proc_file != proc_buf)
+ free (proc_file);
+ /* If the syscall succeeds, or if it fails with an unexpected
+ errno value, then return right away. Otherwise, fall through
+ and resort to using save_cwd/restore_cwd. */
+ if (FUNC_FAIL != proc_result)
+ return proc_result;
+ if (! EXPECTED_ERRNO (proc_errno))
+ {
+ errno = proc_errno;
+ return proc_result;
+ }
}
}
if (save_cwd (&saved_cwd) != 0)
openat_save_fail (errno);
+ if (0 <= fd && fd == saved_cwd.desc)
+ {
+ /* If saving the working directory collides with the user's
+ requested fd, then the user's fd must have been closed to
+ begin with. */
+ free_cwd (&saved_cwd);
+ errno = EBADF;
+ return FUNC_FAIL;
+ }
if (fchdir (fd) != 0)
{
saved_errno = errno;
free_cwd (&saved_cwd);
errno = saved_errno;
- return -1;
+ return FUNC_FAIL;
}
err = CALL_FUNC (file);
- saved_errno = (err < 0 ? errno : 0);
+ saved_errno = (err == FUNC_FAIL ? errno : 0);
if (restore_cwd (&saved_cwd) != 0)
openat_restore_fail (errno);
if (saved_errno)
errno = saved_errno;
return err;
+ }
+#endif
}
#undef CALL_FUNC
+#undef FUNC_RESULT
+#undef FUNC_FAIL
projects / gnulib.git / blobdiff