aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/mach/hurd/getgroups.c
blob: bf5de3b3484579aa524b0f469897465440533b22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
/* Copyright (C) 1993-2015 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/id.h>
#include <string.h>

int
__getgroups (n, gidset)
     int n;
     gid_t *gidset;
{
  error_t err;
  int ngids;
  void *crit;

  if (n < 0)
    return __hurd_fail (EINVAL);

  crit = _hurd_critical_section_lock ();
  __mutex_lock (&_hurd_id.lock);

  if (err = _hurd_check_ids ())
    {
      __mutex_unlock (&_hurd_id.lock);
      _hurd_critical_section_unlock (crit);
      return __hurd_fail (err);
    }

  ngids = _hurd_id.gen.ngids;

  if (n != 0)
    {
      /* Copy the gids onto stack storage and then release the idlock.  */
      gid_t gids[ngids];
      memcpy (gids, _hurd_id.gen.gids, sizeof (gids));
      __mutex_unlock (&_hurd_id.lock);
      _hurd_critical_section_unlock (crit);

      /* Now that the lock is released, we can safely copy the
	 group set into the user's array, which might fault.  */
      if (ngids > n)
	return __hurd_fail (EINVAL);
      memcpy (gidset, gids, ngids * sizeof (gid_t));
    }
  else
    {
      __mutex_unlock (&_hurd_id.lock);
      _hurd_critical_section_unlock (crit);
    }

  return ngids;
}

weak_alias (__getgroups, getgroups)