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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 17:47:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 17:47:50 +0000
commitbbe35a6e1b54ef5cd7c1c471886c30ba85c0804e (patch)
tree985a31e8c860c690d9f20e6621ce5fcc05ccd244 /lib/at-func.c
parentInitial commit. (diff)
downloadwget-bbe35a6e1b54ef5cd7c1c471886c30ba85c0804e.tar.xz
wget-bbe35a6e1b54ef5cd7c1c471886c30ba85c0804e.zip
Adding upstream version 1.21.upstream/1.21upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/at-func.c')
-rw-r--r--lib/at-func.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/lib/at-func.c b/lib/at-func.c
new file mode 100644
index 0000000..90022e0
--- /dev/null
+++ b/lib/at-func.c
@@ -0,0 +1,146 @@
+/* Define at-style functions like fstatat, unlinkat, fchownat, etc.
+ Copyright (C) 2006, 2009-2020 Free Software Foundation, Inc.
+
+ 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 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
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ 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, see <https://www.gnu.org/licenses/>. */
+
+/* written by Jim Meyering */
+
+#include "filename.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
+
+#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. */
+FUNC_RESULT
+AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS)
+{
+ 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
+ {
+ /* 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)
+ {
+ 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 FUNC_FAIL;
+ }
+
+ err = CALL_FUNC (file);
+ saved_errno = (err == FUNC_FAIL ? errno : 0);
+
+ if (restore_cwd (&saved_cwd) != 0)
+ openat_restore_fail (errno);
+
+ free_cwd (&saved_cwd);
+
+ if (saved_errno)
+ errno = saved_errno;
+ return err;
+ }
+#endif
+}
+#undef CALL_FUNC
+#undef FUNC_RESULT
+#undef FUNC_FAIL