glibc/sysdeps/mach/hurd/setegid.c
1995-02-18 01:27:10 +00:00

68 lines
2.0 KiB
C

/* Copyright (C) 1993, 1994 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <sys/types.h>
#include <hurd/id.h>
#include <string.h>
/* Set the effective user ID of the calling process to GID. */
int
DEFUN(setegid, (gid), gid_t gid)
{
auth_t newauth;
error_t err;
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_id.lock);
err = _hurd_check_ids ();
if (!err)
{
/* Make a new auth handle which has EGID as the first element in the
list of effective gids. */
size_t ngen = _hurd_id.gen.ngids < 1 ? 1 : _hurd_id.gen.ngids;
gid_t newgen[ngen];
newgen[0] = gid;
memcpy (&newgen[1], _hurd_id.gen.gids, (ngen - 1) * sizeof (gid_t));
err = __USEPORT (AUTH, __auth_makeauth
(port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
_hurd_id.gen.uids, _hurd_id.gen.nuids,
_hurd_id.aux.uids, _hurd_id.aux.nuids,
newgen, ngen,
_hurd_id.aux.gids, _hurd_id.aux.ngids,
&newauth));
}
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (err)
return __hurd_fail (err);
/* Install the new handle and reauthenticate everything. */
err = __setauth (newauth);
__mach_port_deallocate (__mach_task_self (), newauth);
return err;
}