summaryrefslogtreecommitdiff
path: root/libfshelp/fetch-control.c
blob: 91c65bb0f77a91564b82bd7071ed985d40ef4b56 (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
/* 
   Copyright (C) 1995 Free Software Foundation, Inc.
   Written by Michael I. Bushnell.

   This file is part of the GNU Hurd.

   The GNU Hurd is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   The GNU Hurd 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
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include "fshelp.h"
#include <assert.h>

error_t
fshelp_fetch_control (struct transbox *box,
		      mach_port_t *control)
{
  error_t err = 0;
  *control = box->active;
  if (*control != MACH_PORT_NULL)
    err = mach_port_mod_refs (mach_task_self (), *control,
                              MACH_PORT_RIGHT_SEND, 1);

  if (err == KERN_INVALID_RIGHT)
    {
      err = mach_port_deallocate (mach_task_self (), *control);
      assert_perror (err);
      *control = box->active = MACH_PORT_NULL;
    }

  return err;
}