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

   1 /* Copyright (C) 1998, 2000, 2003, 2006 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 <sys/types.h>
  21 #include <sys/fsuid.h>
  22
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25
  26 #include <linux/posix_types.h>
  27 #include <kernel-features.h>
  28
  29 #ifdef __NR_setfsuid
  30
  31 # ifdef __NR_setfsuid32
  32 #  if __ASSUME_32BITUIDS == 0
  33 /* This variable is shared with all files that need to check for 32bit
  34    uids.  */
  35 extern int __libc_missing_32bit_uids attribute_hidden;
  36 #  endif
  37 # endif /* __NR_setfsuid32 */
  38
  39 int
  40 setfsuid (uid_t uid)
  41 {
  42   INTERNAL_SYSCALL_DECL (err);
  43 # if  __ASSUME_32BITUIDS > 0
  44   /* No error checking. */
  45   return INTERNAL_SYSCALL (setfsuid32, err, 1, uid);
  46 # else
  47 #  ifdef __NR_setfsuid32
  48   if (__libc_missing_32bit_uids <= 0)
  49     {
  50       int result;
  51
  52       result = INTERNAL_SYSCALL (setfsuid32, err, 1, uid);
  53       if (! INTERNAL_SYSCALL_ERROR_P (result, err)
  54           || INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
  55         return result;
  56
  57       __libc_missing_32bit_uids = 1;
  58     }
  59 #  endif /* __NR_setfsuid32 */
  60
  61   if (uid != (uid_t) ((__kernel_uid_t) uid))
  62     {
  63       __set_errno (EINVAL);
  64       return -1;
  65     }
  66
  67   /* No error checking. */
  68   return INTERNAL_SYSCALL (setfsuid, err, 1, uid);
  69 # endif
  70 }
  71 #endif