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

   1 /* Copyright (C) 1998,2000,2002,2003,2004,2005,2006
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <setxid.h>
  23 #include <linux/posix_types.h>
  24 #include <kernel-features.h>
  25
  26
  27 #if defined __NR_setresuid || defined __NR_setresuid32
  28
  29 # ifdef __NR_setresuid32
  30 #  if __ASSUME_32BITUIDS == 0
  31 /* This variable is shared with all files that need to check for 32bit
  32    uids.  */
  33 extern int __libc_missing_32bit_uids;
  34 #  endif
  35 # endif /* __NR_setresuid32 */
  36
  37 int
  38 __setresuid (uid_t ruid, uid_t euid, uid_t suid)
  39 {
  40   int result;
  41
  42 # if __ASSUME_32BITUIDS > 0 || !defined __NR_setresuid
  43   result = INLINE_SETXID_SYSCALL (setresuid32, 3, ruid, euid, suid);
  44 # else
  45 #  ifdef __NR_setresuid32
  46   if (__libc_missing_32bit_uids <= 0)
  47     {
  48       int saved_errno = errno;
  49
  50       result = INLINE_SETXID_SYSCALL (setresuid32, 3, ruid, euid, suid);
  51       if (result == 0)
  52         goto out;
  53       if (errno != ENOSYS)
  54         return result;
  55
  56       __set_errno (saved_errno);
  57       __libc_missing_32bit_uids = 1;
  58     }
  59 #  endif /* __NR_setresuid32 */
  60
  61   if (((ruid + 1) > (uid_t) ((__kernel_uid_t) -1U))
  62       || ((euid + 1) > (uid_t) ((__kernel_uid_t) -1U))
  63       || ((suid + 1) > (uid_t) ((__kernel_uid_t) -1U)))
  64     {
  65       __set_errno (EINVAL);
  66       return -1;
  67     }
  68
  69   result = INLINE_SETXID_SYSCALL (setresuid, 3, ruid, euid, suid);
  70 #  ifdef __NR_setresuid32
  71  out:
  72 #  endif
  73 # endif
  74
  75   return result;
  76 }
  77 libc_hidden_def (__setresuid)
  78 #ifndef __setresuid
  79 weak_alias (__setresuid, setresuid)
  80 #endif
  81
  82 #else
  83
  84 #include <posix/setresuid.c>
  85
  86 #endif