glibc/sysdeps/mach/hurd/getgroups.c

70 lines
1.9 KiB
C

/* Copyright (C) 1993-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/id.h>
#include <string.h>
int
__getgroups (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)