1 /* getresuid -- fetch real user ID, effective user ID, and saved-set user ID
2    Copyright (C) 2002-2022 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
__getresuid(uid_t * ruid,uid_t * euid,uid_t * suid)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)
61