dev = &tun->dev;
device_init(dev, &tunnel_device_type, name);
tun->set_state = dev->set_state;
dev->set_state = tunnel_set_state;
dev = &tun->dev;
device_init(dev, &tunnel_device_type, name);
tun->set_state = dev->set_state;
dev->set_state = tunnel_set_state;