Workaround for NoClassDefFound issue in Netty.

SimpleChannelInboundHandler generates `message` instance check code on the fly,
using JavaAssist. Which was not working, when a new Connection was created on the thread
outside of NettyMessagingManager bundle, which did not have access to netty classes.
- Implemented equivalent for SimpleChannelInboundHandler<InternaleMessage>
  without specifying type parameter, avoiding on the fly code generation.

Other changes:
- Add a method in IpAddress to return InetAddress instance.

Change-Id: Ie97294a5650683457b9395e773269c5232d8e602

@@ -23,5 +23,4 @@ osgi_jar_with_tests (
     deps = COMPILE_DEPS,
     test_deps = TEST_DEPS,
     visibility = ['PUBLIC'],
-    dynamicimport_packages = 'io.netty.*',
 )

@@ -116,22 +116,4 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-
-            <plugin>
-                <groupId>org.apache.felix</groupId>
-                <artifactId>maven-bundle-plugin</artifactId>
-                <extensions>true</extensions>
-                <configuration>
-                    <instructions>
-                        <DynamicImport-Package>
-                            io.netty.*
-                        </DynamicImport-Package>
-                    </instructions>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
 </project>

@@ -32,7 +32,11 @@ import java.io.IOException;
  * Encode InternalMessage out into a byte buffer.
  */
 @Sharable
-public class MessageEncoder extends MessageToByteEncoder<InternalMessage> {
+public class MessageEncoder extends MessageToByteEncoder<Object> {
+// Effectively MessageToByteEncoder<InternalMessage>,
+// had to specify <Object> to avoid Class Loader not being able to find some classes.
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final int preamble;
 
@@ -41,14 +45,15 @@ public class MessageEncoder extends MessageToByteEncoder<InternalMessage> {
         this.preamble = preamble;
     }
 
-    private final Logger log = LoggerFactory.getLogger(getClass());
 
     @Override
     protected void encode(
             ChannelHandlerContext context,
-            InternalMessage message,
+            Object rawMessage,
             ByteBuf out) throws Exception {
 
+        InternalMessage message = (InternalMessage) rawMessage;
+
         out.writeInt(this.preamble);
 
         // write time
@@ -100,4 +105,10 @@ public class MessageEncoder extends MessageToByteEncoder<InternalMessage> {
         }
         context.close();
     }
+
+    // Effectively same result as one generated by MessageToByteEncoder<InternalMessage>
+    @Override
+    public final boolean acceptOutboundMessage(Object msg) throws Exception {
+        return msg instanceof InternalMessage;
+    }
 }

@@ -41,7 +41,6 @@ import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
-
 import org.apache.commons.pool.KeyedPoolableObjectFactory;
 import org.apache.commons.pool.impl.GenericKeyedObjectPool;
 import org.apache.felix.scr.annotations.Activate;
@@ -383,7 +382,7 @@ public class NettyMessagingManager implements MessagingService {
             }
             // Start the client.
             CompletableFuture<Channel> retFuture = new CompletableFuture<>();
-            ChannelFuture f = bootstrap.connect(ep.host().toString(), ep.port());
+            ChannelFuture f = bootstrap.connect(ep.host().toInetAddress(), ep.port());
 
             f.addListener(future -> {
                 if (future.isSuccess()) {
@@ -491,10 +490,13 @@ public class NettyMessagingManager implements MessagingService {
     }
 
     @ChannelHandler.Sharable
-    private class InboundMessageDispatcher extends SimpleChannelInboundHandler<InternalMessage> {
+    private class InboundMessageDispatcher extends SimpleChannelInboundHandler<Object> {
+     // Effectively SimpleChannelInboundHandler<InternalMessage>,
+     // had to specify <Object> to avoid Class Loader not being able to find some classes.
 
         @Override
-        protected void channelRead0(ChannelHandlerContext ctx, InternalMessage message) throws Exception {
+        protected void channelRead0(ChannelHandlerContext ctx, Object rawMessage) throws Exception {
+            InternalMessage message = (InternalMessage) rawMessage;
             try {
                 dispatchLocally(message);
             } catch (RejectedExecutionException e) {
@@ -507,7 +509,21 @@ public class NettyMessagingManager implements MessagingService {
             log.error("Exception inside channel handling pipeline.", cause);
             context.close();
         }
+
+        /**
+         * Returns true if the given message should be handled.
+         *
+         * @param msg inbound message
+         * @return true if {@code msg} is {@link InternalMessage} instance.
+         *
+         * @see SimpleChannelInboundHandler#acceptInboundMessage(Object)
+         */
+        @Override
+        public final boolean acceptInboundMessage(Object msg) {
+            return msg instanceof InternalMessage;
+        }
     }
+
     private void dispatchLocally(InternalMessage message) throws IOException {
         if (message.preamble() != preamble) {
             log.debug("Received {} with invalid preamble from {}", message.type(), message.sender());

@@ -16,6 +16,7 @@
 package org.onlab.packet;
 
 import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.nio.ByteBuffer;
@@ -142,6 +143,20 @@ public class IpAddress implements Comparable<IpAddress> {
     }
 
     /**
+     * Returns the IP address as InetAddress.
+     *
+     * @return InetAddress
+     */
+    public InetAddress toInetAddress() {
+        try {
+            return InetAddress.getByAddress(octets);
+        } catch (UnknownHostException e) {
+            // Should never reach here
+            return null;
+        }
+    }
+
+    /**
      * Computes the IP address byte length for a given IP version.
      *
      * @param version the IP version