summaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/fchmodat.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/unix/sysv/linux/fchmodat.c')
-rw-r--r--sysdeps/unix/sysv/linux/fchmodat.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/fchmodat.c b/sysdeps/unix/sysv/linux/fchmodat.c
new file mode 100644
index 0000000000..de35e4376f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/fchmodat.c
@@ -0,0 +1,87 @@
+/* Change the protections of file relative to open directory. Linux version.
+ Copyright (C) 2006 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <alloca.h>
+#include <sysdep.h>
+
+int
+fchmodat (fd, file, mode, flag)
+ int fd;
+ const char *file;
+ mode_t mode;
+ int flag;
+{
+ if (flag & ~AT_SYMLINK_NOFOLLOW)
+ {
+ __set_errno (EINVAL);
+ return -1;
+ }
+#ifndef __NR_lchmod /* Linux so far has no lchmod syscall. */
+ if (flag & AT_SYMLINK_NOFOLLOW)
+ {
+ __set_errno (ENOTSUP);
+ return -1;
+ }
+#endif
+
+ char *buf = NULL;
+
+ if (fd != AT_FDCWD && file[0] != '/')
+ {
+ size_t filelen = strlen (file);
+ static const char procfd[] = "/proc/self/fd/%d/%s";
+ /* Buffer for the path name we are going to use. It consists of
+ - the string /proc/self/fd/
+ - the file descriptor number
+ - the file name provided.
+ The final NUL is included in the sizeof. A bit of overhead
+ due to the format elements compensates for possible negative
+ numbers. */
+ size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
+ buf = alloca (buflen);
+
+ __snprintf (buf, buflen, procfd, fd, file);
+ file = buf;
+ }
+
+ int result;
+ INTERNAL_SYSCALL_DECL (err);
+
+#ifdef __NR_lchmod
+ if (flag & AT_SYMLINK_NOFOLLOW)
+ result = INTERNAL_SYSCALL (lchmod, err, 2, file, mode);
+ else
+#endif
+ result = INTERNAL_SYSCALL (chmod, err, 2, file, mode);
+
+ if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0))
+ {
+ __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);
+ result = -1;
+ }
+
+ return result;
+}