1  /* getresuid -- fetch real user ID, effective user ID, and saved-set user ID
       2     Copyright (C) 2002-2023 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, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <unistd.h>
      21  #include <hurd.h>
      22  #include <hurd/id.h>
      23  
      24  /* Fetch the real user ID, effective user ID, and saved-set user ID,
      25     of the calling process.  */
      26  int
      27  __getresuid (uid_t *ruid, uid_t *euid, uid_t *suid)
      28  {
      29    error_t err;
      30  
      31  retry:
      32    HURD_CRITICAL_BEGIN;
      33    __mutex_lock (&_hurd_id.lock);
      34  
      35    err = _hurd_check_ids ();
      36    if (!err)
      37      {
      38        if (_hurd_id.aux.nuids < 1)
      39  	/* We do not even have a real UID.  */
      40  	err = EGRATUITOUS;
      41        else
      42  	{
      43  	  uid_t real = _hurd_id.aux.uids[0];
      44  
      45  	  *ruid = real;
      46  	  *euid = _hurd_id.gen.nuids < 1 ? real : _hurd_id.gen.uids[0];
      47  	  *suid = _hurd_id.aux.nuids < 2 ? real : _hurd_id.aux.uids[1];
      48  	}
      49      }
      50  
      51    __mutex_unlock (&_hurd_id.lock);
      52    HURD_CRITICAL_END;
      53    if (err == EINTR)
      54      /* Got a signal while inside an RPC of the critical section, retry again */
      55      goto retry;
      56  
      57    return __hurd_fail (err);
      58  }
      59  libc_hidden_def (__getresuid)
      60  weak_alias (__getresuid, getresuid)