/* Copyright (C) 2005, 2006, 2009 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 <http://www.gnu.org/licenses/>. */ #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> #include <kernel-features.h> /* Change the owner and group of FILE. */ int fchownat (fd, file, owner, group, flag) int fd; const char *file; uid_t owner; gid_t group; int flag; { int result; #ifdef __NR_fchownat # ifndef __ASSUME_ATFCTS if (__have_atfcts >= 0) # endif { result = INLINE_SYSCALL (fchownat, 5, fd, file, owner, group, flag); # ifndef __ASSUME_ATFCTS if (result == -1 && errno == ENOSYS) __have_atfcts = -1; else # endif return result; } #endif #ifndef __ASSUME_ATFCTS if (flag & ~AT_SYMLINK_NOFOLLOW) { __set_errno (EINVAL); return -1; } char *buf = NULL; if (fd != AT_FDCWD && file[0] != '/') { size_t filelen = strlen (file); if (__builtin_expect (filelen == 0, 0)) { __set_errno (ENOENT); return -1; } 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; } INTERNAL_SYSCALL_DECL (err); if (flag & AT_SYMLINK_NOFOLLOW) result = INTERNAL_SYSCALL (lchown, err, 3, file, owner, group); else result = INTERNAL_SYSCALL (chown, err, 3, file, owner, group); if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0)) { __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf); result = -1; } return result; #endif }