sysdeps/unix/sysv/linux/i386/fchown.c

   1 /* Copyright (C) 2000, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21
  22 #include <sysdep.h>
  23 #include <sys/syscall.h>
  24
  25 #include <linux/posix_types.h>
  26 #include "kernel-features.h"
  27
  28 #ifdef __NR_fchown32
  29 # if __ASSUME_32BITUIDS == 0
  30 /* This variable is shared with all files that need to check for 32bit
  31    uids.  */
  32 extern int __libc_missing_32bit_uids;
  33 # endif
  34 #endif /* __NR_fchown32 */
  35
  36 int
  37 __fchown (int fd, uid_t owner, gid_t group)
  38 {
  39 #if  __ASSUME_32BITUIDS > 0
  40   return INLINE_SYSCALL (fchown32, 3, fd, owner, group);
  41 #else
  42 # ifdef __NR_fchown32
  43   if (__libc_missing_32bit_uids <= 0)
  44     {
  45       int result;
  46       int saved_errno = errno;
  47
  48       result = INLINE_SYSCALL (fchown32, 3, fd, owner, group);
  49       if (result == 0 || errno != ENOSYS)
  50         return result;
  51
  52       __set_errno (saved_errno);
  53       __libc_missing_32bit_uids = 1;
  54     }
  55 # endif /* __NR_fchown32 */
  56
  57   if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U))
  58       || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
  59     {
  60       __set_errno (EINVAL);
  61       return -1;
  62     }
  63
  64   return INLINE_SYSCALL (fchown, 3, fd, owner, group);
  65 #endif
  66 }
  67
  68 weak_alias (__fchown, fchown)