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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <sys/types.h>
  20 #include <sys/fsuid.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_setfsuid
  29
  30 # ifdef __NR_setfsuid32
  31 #  if __ASSUME_32BITUIDS == 0
  32 /* This variable is shared with all files that need to check for 32bit
  33    uids.  */
  34 extern int __libc_missing_32bit_uids attribute_hidden;
  35 #  endif
  36 # endif /* __NR_setfsuid32 */
  37
  38 int
  39 setfsuid (uid_t uid)
  40 {
  41   INTERNAL_SYSCALL_DECL (err);
  42 # if  __ASSUME_32BITUIDS > 0
  43   /* No error checking. */
  44   return INTERNAL_SYSCALL (setfsuid32, err, 1, uid);
  45 # else
  46 #  ifdef __NR_setfsuid32
  47   if (__libc_missing_32bit_uids <= 0)
  48     {
  49       int result;
  50
  51       result = INTERNAL_SYSCALL (setfsuid32, err, 1, uid);
  52       if (! INTERNAL_SYSCALL_ERROR_P (result, err)
  53           || INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
  54         return result;
  55
  56       __libc_missing_32bit_uids = 1;
  57     }
  58 #  endif /* __NR_setfsuid32 */
  59
  60   if (uid != (uid_t) ((__kernel_uid_t) uid))
  61     {
  62       __set_errno (EINVAL);
  63       return -1;
  64     }
  65
  66   /* No error checking. */
  67   return INTERNAL_SYSCALL (setfsuid, err, 1, uid);
  68 # endif
  69 }
  70 #endif