Added yet another player hook method.

This method works by injecting into the NetServerHandler object
of a player. That way, we can also intercept map chunk packets.

ProtocolLib/src/com/comphenix/protocol/injector/NetworkServerInjector.java

@@ -0,0 +1,115 @@
+package com.comphenix.protocol.injector;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Set;
+
+import net.minecraft.server.Packet;
+import net.sf.cglib.proxy.Enhancer;
+import net.sf.cglib.proxy.Factory;
+import net.sf.cglib.proxy.MethodInterceptor;
+import net.sf.cglib.proxy.MethodProxy;
+
+import org.bukkit.entity.Player;
+
+import com.comphenix.protocol.reflect.FuzzyReflection;
+
+/**
+ * Represents a player hook into the NetServerHandler class. 
+ * 
+ * @author Kristian
+ */
+public class NetworkServerInjector extends PlayerInjector {
+
+	private static Method sendPacket;
+	
+	public NetworkServerInjector(Player player, PacketFilterManager manager, Set<Integer> sendingFilters) throws IllegalAccessException {
+		super(player, manager, sendingFilters);
+	}
+	
+	@Override
+	protected void initialize() throws IllegalAccessException {
+		super.initialize();
+		
+		// Get the send packet method!
+		if (hasInitialized) {
+			if (sendPacket == null)
+				sendPacket = FuzzyReflection.fromObject(serverHandler).getMethodByParameters("sendPacket", Packet.class);
+		}
+	}
+
+	@Override
+	public void sendServerPacket(Packet packet, boolean filtered) throws InvocationTargetException {
+		Object serverDeleage = filtered ? serverHandlerRef.getValue() : serverHandlerRef.getOldValue();
+		
+		if (serverDeleage != null) {
+			try {
+				// Note that invocation target exception is a wrapper for a checked exception
+				sendPacket.invoke(serverDeleage, packet);
+				
+			} catch (IllegalArgumentException e) {
+				throw e;
+			} catch (InvocationTargetException e) {
+				throw e;
+			} catch (IllegalAccessException e) {
+				throw new IllegalStateException("Unable to access send packet method.", e);
+			}
+		} else {
+			throw new IllegalStateException("Unable to load server handler. Cannot send packet.");
+		}
+	}
+
+	@Override
+	public void injectManager() {
+		if (serverHandlerRef == null)
+			throw new IllegalStateException("Cannot find server handler.");
+		// Don't inject twice
+		if (serverHandlerRef.getValue() instanceof Factory)
+			return;
+		
+		Enhancer ex = new Enhancer();
+		ex.setClassLoader(manager.getClassLoader());
+		ex.setSuperclass(serverHandler.getClass());
+		ex.setCallback(new MethodInterceptor() {
+			@Override
+			public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
+				// The send packet method!
+				if (method.equals(sendPacket)) {
+					Packet packet = (Packet) args[0];
+					
+					if (packet != null) {
+						packet = handlePacketRecieved(packet);
+						
+						// A NULL packet indicate cancelling
+						if (packet != null)
+							args[0] = packet;
+						else
+							return null;
+					}
+				}
+				
+				// Delegate to our underlying class
+				try {
+					return method.invoke(serverHandler, args);
+				} catch (InvocationTargetException e) {
+					throw e.getCause();
+				}
+			}
+		});
+		
+		// Inject it now
+		serverHandlerRef.setValue(ex.create());
+	}
+
+	@Override
+	public void cleanupAll() {
+		if (serverHandlerRef != null)
+			serverHandlerRef.revertValue();
+	}
+
+	@Override
+	public boolean canInject() {
+		// Probably always
+		return true;
+	}
+}

ProtocolLib/src/com/comphenix/protocol/injector/PacketFilterManager.java

@@ -61,13 +61,22 @@ public final class PacketFilterManager implements ProtocolManager {
 	public enum PlayerInjectHooks {
 		/**
 		 * Override the packet queue lists in NetworkHandler. 
+		 * <p>
+		 * Cannot intercept MapChunk packets. 
 		 */
 		NETWORK_HANDLER_FIELDS,
 		
 		/**
-		 * Override the network handler object itself.
+		 * Override the network handler object itself. Only works in 1.3.
+		 * <p>
+		 * Cannot intercept MapChunk packets. 
 		 */
 		NETWORK_MANAGER_OBJECT,
+		
+		/**
+		 * Override the server handler object. Versatile, but slow.
+		 */
+		NETWORK_SERVER_OBJECT;
 	}
 	
 	// Create a concurrent set
@@ -79,7 +88,7 @@ public final class PacketFilterManager implements ProtocolManager {
 	private Map<Player, PlayerInjector> playerInjection = new HashMap<Player, PlayerInjector>();
 	
 	// Player injection type
-	private PlayerInjectHooks playerHook = PlayerInjectHooks.NETWORK_HANDLER_FIELDS;
+	private PlayerInjectHooks playerHook = PlayerInjectHooks.NETWORK_SERVER_OBJECT;
 	
 	// Packet injection
 	private PacketInjector packetInjector;
@@ -373,6 +382,8 @@ public final class PacketFilterManager implements ProtocolManager {
 			return new NetworkFieldInjector(player, this, sendingFilters);
 		case NETWORK_MANAGER_OBJECT: 
 			return new NetworkObjectInjector(player, this, sendingFilters);
+		case NETWORK_SERVER_OBJECT:
+			return new NetworkServerInjector(player, this, sendingFilters);
 		default:
 			throw new IllegalArgumentException("Cannot construct a player injector.");
 		}

ProtocolLib/src/com/comphenix/protocol/injector/PlayerInjector.java

@@ -56,9 +56,11 @@ abstract class PlayerInjector {
 	
 	// Reference to the player's network manager
 	protected VolatileField networkManagerRef;
+	protected VolatileField serverHandlerRef;
 	protected Object networkManager;
 	
 	// Current net handler
+	protected Object serverHandler;
 	protected Object netHandler;
 	
 	// The packet manager and filters
@@ -75,12 +77,18 @@ abstract class PlayerInjector {
 		initialize();
 	}
 
+	/**
+	 * Retrieve the notch (NMS) entity player object.
+	 * @return Notch player object.
+	 */
+	protected EntityPlayer getEntityPlayer() {
+		CraftPlayer craft = (CraftPlayer) player;
+		return craft.getHandle();
+	}
+	
 	protected void initialize() throws IllegalAccessException {
 	
-		CraftPlayer craft = (CraftPlayer) player;
+		EntityPlayer notchEntity = getEntityPlayer();
-		EntityPlayer notchEntity = craft.getHandle();
-		
-		Object serverHandler = null;
 		
 		if (!hasInitialized) {
 			// Do this first, in case we encounter an exception
@@ -89,7 +97,8 @@ abstract class PlayerInjector {
 			// Retrieve the server handler
 			if (serverHandlerField == null)
 				serverHandlerField = FuzzyReflection.fromObject(notchEntity).getFieldByType(".*NetServerHandler");
-			serverHandler = FieldUtils.readField(serverHandlerField, notchEntity);
+			serverHandlerRef = new VolatileField(serverHandlerField, notchEntity);
+			serverHandler = serverHandlerRef.getValue();
 			
 			// Next, get the network manager 
 			if (networkManagerField == null)