sysdeps/mach/hurd/setreuid.c

   1 /* Copyright (C) 1991 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22
  23 int
  24 __setreuid (uid_t ruid, uid_t euid)
  25 {
  26   auth_t newauth;
  27   int i;
  28
  29   __mutex_lock (&_hurd_idlock);
  30   if (!_hurd_id_valid)
  31     {
  32       error_t err = __auth_getids (_hurd_auth, &_hurd_id);
  33       if (err)
  34         {
  35           __mutex_unlock (&_hurd_idlock);
  36           return __hurd_fail (err);
  37         }
  38       _hurd_id_valid = 1;
  39     }
  40
  41   for (i = 0; i < _hurd_id.nuids; ++i)
  42     if (_hurd_id.uids[i] == euid)
  43       {
  44         /* We already have this euid.  Swap it with uids[0]
  45            so getuid will return it.  */
  46         _hurd_id.uids[i] = _hurd_id.uids[0];
  47         break;
  48       }
  49
  50   if (i == _hurd_id.nuids)
  51     {
  52       if (_hurd_id.nuids == sizeof (_hurd_id.uids) / sizeof (_hurd_id.uids[0]))
  53         {
  54           __mutex_unlock (&_hurd_idlock);
  55           errno = ENOMEM;       /* ? */
  56           return -1;
  57         }
  58       else
  59         {
  60           _hurd_id.uids[_hurd_id.nuids++] = _hurd_id.uids[0];
  61           _hurd_id.uids[0] = euid;
  62         }
  63     }
  64
  65   _hurd_id.ruid = ruid;
  66
  67   if (err = auth_makeauth (_hurd_auth, &_hurd_id, &newauth))
  68     {
  69       _hurd_id_valid = 0;
  70       __mutex_unlock (&_hurd_idlock);
  71       return __hurd_fail (err);
  72     }
  73   else
  74     {
  75       int err = __setauth (newauth);
  76       __mach_port_deallocate (__mach_task_self (), newauth);
  77       return err;
  78     }
  79 }