/*
* $Id$
*
* 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.net.service;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.apache.log4j.Logger;
import org.jnode.driver.ApiNotFoundException;
import org.jnode.driver.Device;
import org.jnode.driver.net.NetDeviceAPI;
import org.jnode.driver.net.NetworkException;
import org.jnode.net.LayerAlreadyRegisteredException;
import org.jnode.net.NetworkLayer;
import org.jnode.net.NetworkLayerManager;
import org.jnode.net.NoSuchProtocolException;
import org.jnode.net.SocketBuffer;
import org.jnode.plugin.ConfigurationElement;
import org.jnode.plugin.Extension;
import org.jnode.plugin.ExtensionPoint;
import org.jnode.plugin.ExtensionPointListener;
import org.jnode.util.NumberUtils;
import org.jnode.util.Queue;
import org.jnode.util.QueueProcessor;
/**
* @author epr
*/
public class DefaultNetworkLayerManager implements NetworkLayerManager,
QueueProcessor<SocketBuffer>, ExtensionPointListener {
/** My logger */
private static final Logger log = Logger.getLogger(DefaultNetworkLayerManager.class);
/** Registered packet types */
private final HashMap<Integer, NetworkLayer> layers = new HashMap<Integer, NetworkLayer>();
/** Queue of received packets */
private final Queue<SocketBuffer> packetQueue = new Queue<SocketBuffer>();
/** The networkLayers extension-point */
private final ExtensionPoint networkLayersEP;
/**
* Initialize a new instance
*
* @param networkLayersEP
*/
public DefaultNetworkLayerManager(ExtensionPoint networkLayersEP) {
this.networkLayersEP = networkLayersEP;
networkLayersEP.addListener(this);
refreshNetworkLayers();
}
/**
* Register a packet type.
*
* @param pt
*/
protected synchronized void registerNetworkLayer(NetworkLayer pt)
throws LayerAlreadyRegisteredException {
layers.put(pt.getProtocolID(), pt);
}
/**
* Unregister a packet type. If the packettype has not been registered, this
* method returns without an error.
*
* @param pt
*/
public synchronized void unregisterNetworkLayer(NetworkLayer pt) {
layers.remove(pt);
}
/**
* Get all register packet types.
*
* @return A collection of PacketType instances
*/
public synchronized Collection<NetworkLayer> getNetworkLayers() {
return new ArrayList<NetworkLayer>(layers.values());
}
/**
* Gets the packet type for a given protocol ID
*
* @param protocolID
* @throws NoSuchProtocolException
*/
public NetworkLayer getNetworkLayer(int protocolID) throws NoSuchProtocolException {
final NetworkLayer pt = (NetworkLayer) layers.get(Integer.valueOf(protocolID));
if (pt == null) {
throw new NoSuchProtocolException("protocolID " + protocolID);
}
return pt;
}
/**
* Process a packet that has been received. The receive method of all those
* packettypes that have a matching type and allow the device(of the packet)
* is called. The packet is cloned if more then 1 packettypes want to
* receive the packet.
*
* @param skbuf
*/
public void receive(SocketBuffer skbuf) {
packetQueue.add(skbuf);
}
/**
* Process the received packet
*
* @param skbuf
*/
public synchronized void process(SocketBuffer skbuf) {
try {
final int protoID = skbuf.getProtocolID();
final Device dev = skbuf.getDevice();
if (dev == null) {
throw new NetworkException("Device not set on SocketBuffer");
}
final NetDeviceAPI deviceAPI;
try {
deviceAPI = dev.getAPI(NetDeviceAPI.class);
} catch (ApiNotFoundException ex) {
throw new NetworkException("Device in SocketBuffer is not a network device");
}
// Find all the packettype that want to process the given packet
try {
final NetworkLayer pt = getNetworkLayer(protoID);
if (pt.isAllowedForDevice(dev)) {
pt.receive(skbuf, deviceAPI);
}
} catch (NoSuchProtocolException ex) {
log.debug("No network layer handler for protocol 0x" + NumberUtils.hex(protoID, 4));
}
} catch (SocketException ex) {
log.error("Cannot process packet", ex);
}
}
/**
* Gets the packet queue
*/
protected final Queue<SocketBuffer> getQueue() {
return packetQueue;
}
/**
* Reload the network layer list from the extension-point
*/
protected void refreshNetworkLayers() {
if (networkLayersEP != null) {
layers.clear();
final Extension[] extensions = networkLayersEP.getExtensions();
for (final Extension ext : extensions) {
final ConfigurationElement[] elements = ext.getConfigurationElements();
for (ConfigurationElement element : elements) {
configureLayer(layers, element);
}
}
}
log.debug("Found " + layers.size() + " network layers");
}
private void configureLayer(Map<Integer, NetworkLayer> layers, ConfigurationElement element) {
final String className = element.getAttribute("class");
if (className != null) {
try {
final Class<?> cls =
Thread.currentThread().getContextClassLoader().loadClass(className);
final NetworkLayer layer = (NetworkLayer) cls.newInstance();
layers.put(layer.getProtocolID(), layer);
} catch (ClassNotFoundException ex) {
log.error("Cannot find networklayer class " + className);
} catch (IllegalAccessException ex) {
log.error("Cannot access networklayer class " + className);
} catch (InstantiationException ex) {
log.error("Cannot instantiate networklayer class " + className);
} catch (ClassCastException ex) {
log.error("Networklayer class " + className +
" does not implement the NetworkLayer interface");
}
}
}
/**
* @see org.jnode.plugin.ExtensionPointListener#extensionAdded(org.jnode.plugin.ExtensionPoint,
* org.jnode.plugin.Extension)
*/
public void extensionAdded(ExtensionPoint point, Extension extension) {
refreshNetworkLayers();
}
/**
* @see org.jnode.plugin.ExtensionPointListener#extensionRemoved(org.jnode.plugin.ExtensionPoint,
* org.jnode.plugin.Extension)
*/
public void extensionRemoved(ExtensionPoint point, Extension extension) {
refreshNetworkLayers();
}
}