sysdeps/mach/hurd/setuid.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 /* Set the user ID of the calling process to UID.
  24    If the calling process is the super-user, the real
  25    and effective user IDs, and the saved set-user-ID to UID;
  26    if not, the effective user ID is set to UID.  */
  27 int
  28 DEFUN(__setuid, (uid), uid_t uid)
  29 {
  30   auth_t newauth;
  31   int i;
  32
  33   __mutex_lock (&_hurd_idlock);
  34   if (!_hurd_id_valid)
  35     {
  36       error_t err = __auth_getids (_hurd_auth, &_hurd_id);
  37       if (err)
  38         {
  39           __mutex_unlock (&_hurd_idlock);
  40           return __hurd_fail (err);
  41         }
  42       _hurd_id_valid = 1;
  43     }
  44
  45   for (i = 0; i < _hurd_id.nuids; ++i)
  46     if (_hurd_id.uids[i] == uid)
  47       {
  48         /* We already have this uid.  Swap it with uids[0]
  49            so getuid will return it.  */
  50         _hurd_id.uids[i] = _hurd_id.uids[0];
  51         break;
  52       }
  53
  54   if (i == _hurd_id.nuids)
  55     {
  56       if (_hurd_id.nuids == sizeof (_hurd_id.uids) / sizeof (_hurd_id.uids[0]))
  57         {
  58           __mutex_unlock (&_hurd_idlock);
  59           errno = ENOMEM;       /* ? */
  60           return -1;
  61         }
  62       else
  63         {
  64           _hurd_id.uids[_hurd_id.nuids++] = _hurd_id.uids[0];
  65           _hurd_id.uids[0] = uid;
  66         }
  67     }
  68
  69   _hurd_id.ruid = _hurd_id.uids[0];
  70
  71   if (err = auth_makeauth (_hurd_auth, &_hurd_id, &newauth))
  72     {
  73       _hurd_id_valid = 0;
  74       __mutex_unlock (&_hurd_idlock);
  75       return __hurd_fail (err);
  76     }
  77   else
  78     {
  79       int err = __setauth (newauth);
  80       __mach_port_deallocate (__mach_task_self (), newauth);
  81       return err;
  82     }
  83 }