1 /* Copyright (C) 1993-2022 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 Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the 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    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <errno.h>
19 #include <sys/types.h>
20 #include <grp.h>
21 #include <hurd.h>
22 #include <hurd/id.h>
23 
24 /* Set the group set for the current user to GROUPS (N of them).  */
25 int
setgroups(size_t n,const gid_t * groups)26 setgroups (size_t n, const gid_t *groups)
27 {
28   error_t err;
29   auth_t newauth;
30   size_t i;
31   gid_t new[n];
32 
33   /* Fault before taking locks.  */
34   for (i = 0; i < n; ++i)
35     new[i] = groups[i];
36 
37 retry:
38   HURD_CRITICAL_BEGIN;
39   __mutex_lock (&_hurd_id.lock);
40   err = _hurd_check_ids ();
41   if (! err)
42     {
43       /* Get a new auth port using those IDs.  */
44       err = __USEPORT (AUTH,
45 		       __auth_makeauth (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
46 					_hurd_id.gen.uids, _hurd_id.gen.nuids,
47 					_hurd_id.aux.uids, _hurd_id.aux.nuids,
48 					new, n,
49 					_hurd_id.aux.gids, _hurd_id.aux.ngids,
50 					&newauth));
51     }
52   __mutex_unlock (&_hurd_id.lock);
53   HURD_CRITICAL_END;
54   if (err == EINTR)
55     /* Got a signal while inside an RPC of the critical section, retry again */
56     goto retry;
57 
58   if (err)
59     return __hurd_fail (err);
60 
61   /* Install the new auth port and reauthenticate everything.  */
62   err = __setauth (newauth);
63   __mach_port_deallocate (__mach_task_self (), newauth);
64   return err;
65 }
66 libc_hidden_def (setgroups)
67