/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This 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.
*
* This 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 this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.driver.net.loopback;
import org.jnode.driver.net.NetworkException;
import org.jnode.driver.net.spi.AbstractNetDriver;
import org.jnode.net.HardwareAddress;
import org.jnode.net.SocketBuffer;
import org.jnode.net.ethernet.EthernetAddress;
import org.jnode.net.ethernet.EthernetConstants;
import org.jnode.net.ethernet.EthernetHeader;
import org.jnode.net.ethernet.EthernetUtils;
/**
* Driver for loopback device.
*
* @author epr
* @author Martin Husted Hartvig
*/
public class LoopbackDriver extends AbstractNetDriver implements
EthernetConstants {
private static final EthernetAddress hwAddress = new EthernetAddress(
"00-00-00-00-00-00");
/**
* Gets the hardware address of this device
*/
public HardwareAddress getAddress() {
return hwAddress;
}
/**
* Gets the maximum transfer unit, the number of bytes this device can
* transmit at a time.
*/
public int getMTU() {
return ETH_DATA_LEN;
}
/**
* @see org.jnode.driver.net.spi.AbstractNetDriver#doTransmit(SocketBuffer,
* HardwareAddress)
*/
protected final void doTransmit(SocketBuffer skbuf,
HardwareAddress destination) throws NetworkException {
skbuf.insert(ETH_HLEN);
if (destination != null) {
destination.writeTo(skbuf, 0);
} else {
EthernetAddress.BROADCAST.writeTo(skbuf, 0);
}
getAddress().writeTo(skbuf, 6);
skbuf.set16(12, skbuf.getProtocolID());
onReceive(skbuf);
}
/**
* @see org.jnode.driver.net.spi.AbstractNetDriver#onReceive(org.jnode.net.SocketBuffer)
*/
public void onReceive(SocketBuffer skbuf) throws NetworkException {
// Extract ethernet header
final EthernetHeader hdr = new EthernetHeader(skbuf);
skbuf.setLinkLayerHeader(hdr);
skbuf.setProtocolID(EthernetUtils.getProtocol(hdr));
skbuf.pull(hdr.getLength());
// Send to PM
super.onReceive(skbuf);
}
/**
* @see org.jnode.driver.net.spi.AbstractNetDriver#getDevicePrefix()
*/
protected String getDevicePrefix() {
return LOOPBACK_DEVICE_PREFIX;
}
/**
* @see org.jnode.driver.net.spi.AbstractNetDriver#renameToDevicePrefixOnly()
*/
protected boolean renameToDevicePrefixOnly() {
return true;
}
}