Nearly ready to get a working connection, however few hacks due to own shortcomings and netty shortcomings.

proxy/src/main/java/net/md_5/bungee/ServerConnection.java

@@ -14,6 +14,7 @@ import net.md_5.bungee.packet.PacketFFKick;
 public class ServerConnection implements Server
 {
 
+    @Getter
     private final Channel ch;
     @Getter
     private final ServerInfo info;

proxy/src/main/java/net/md_5/bungee/ServerConnector.java

@@ -7,8 +7,11 @@ import lombok.RequiredArgsConstructor;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.config.ServerInfo;
 import net.md_5.bungee.api.event.ServerConnectedEvent;
+import net.md_5.bungee.connection.DownstreamBridge;
+import net.md_5.bungee.netty.HandlerBoss;
 import net.md_5.bungee.packet.DefinedPacket;
 import net.md_5.bungee.packet.Packet1Login;
+import net.md_5.bungee.packet.Packet2Handshake;
 import net.md_5.bungee.packet.Packet9Respawn;
 import net.md_5.bungee.packet.PacketCDClientStatus;
 import net.md_5.bungee.packet.PacketFDEncryptionRequest;
@@ -35,7 +38,8 @@ public class ServerConnector extends PacketHandler
     public void connected(Channel channel) throws Exception
     {
         this.ch = channel;
-        channel.write( user.handshake );
+        // TODO: Fix this crap
+        channel.write( new Packet2Handshake( user.handshake.procolVersion, user.handshake.username, user.handshake.host, user.handshake.port ) );
         channel.write( PacketCDClientStatus.CLIENT_LOGIN );
     }
 
@@ -91,6 +95,8 @@ public class ServerConnector extends PacketHandler
                 user.getServer().disconnect( "Quitting" );
                 user.getServer().getInfo().removePlayer( user );
             }
+
+            ch.pipeline().get( HandlerBoss.class ).setHandler( new DownstreamBridge( bungee, user ) );
         }
 
         thisState = State.FINISHED;

proxy/src/main/java/net/md_5/bungee/UserConnection.java

@@ -33,7 +33,7 @@ public final class UserConnection implements ProxiedPlayer
 
     public final Packet2Handshake handshake;
     private final ProxyServer bungee;
-    private final Channel ch;
+   public final Channel ch;
     final Packet1Login forgeLogin;
     final List<PacketFAPluginMessage> loginMessages;
     public Queue<DefinedPacket> packetQueue = new ConcurrentLinkedQueue<>();
@@ -69,7 +69,8 @@ public final class UserConnection implements ProxiedPlayer
         this.pendingConnection = pendingConnection;
         this.forgeLogin = forgeLogin;
         this.loginMessages = loginMessages;
-
+        this.name = handshake.username;
+        this.displayName = name;
 
         Collection<String> g = bungee.getConfigurationAdapter().getGroups( name );
         for ( String s : g )

proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java

@@ -3,7 +3,9 @@ package net.md_5.bungee.connection;
 import com.google.common.io.ByteArrayDataInput;
 import com.google.common.io.ByteArrayDataOutput;
 import com.google.common.io.ByteStreams;
+import io.netty.buffer.ByteBuf;
 import lombok.RequiredArgsConstructor;
+import net.md_5.bungee.EntityMap;
 import net.md_5.bungee.UserConnection;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.config.ServerInfo;
@@ -24,6 +26,13 @@ public class DownstreamBridge extends PacketHandler
     private final ProxyServer bungee;
     private final UserConnection con;
 
+    @Override
+    public void handle(ByteBuf buf) throws Exception
+    {
+        EntityMap.rewrite( buf, con.serverEntityId, con.clientEntityId );
+        con.ch.write( buf );
+    }
+
     @Override
     public void handle(Packet0KeepAlive alive) throws Exception
     {

proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java

@@ -177,10 +177,10 @@ public class InitialHandler extends PacketHandler implements PendingConnection
                         }
                     }
 
-                    ch.write( new PacketFCEncryptionResponse() );
-
                     Cipher encrypt = EncryptionUtil.getCipher( Cipher.ENCRYPT_MODE, shared );
                     Cipher decrypt = EncryptionUtil.getCipher( Cipher.DECRYPT_MODE, shared );
+                    ch.write( new PacketFCEncryptionResponse() );
+                    ch.config().setAutoRead( false );
                     ch.pipeline().addBefore( "decoder", "cipher", new CipherCodec( encrypt, decrypt ) );
 
                     thisState = InitialHandler.State.LOGIN;

proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java

@@ -1,6 +1,8 @@
 package net.md_5.bungee.connection;
 
+import io.netty.buffer.ByteBuf;
 import lombok.RequiredArgsConstructor;
+import net.md_5.bungee.EntityMap;
 import net.md_5.bungee.UserConnection;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.event.ChatEvent;
@@ -17,6 +19,13 @@ public class UpstreamBridge extends PacketHandler
     private final ProxyServer bungee;
     private final UserConnection con;
 
+    @Override
+    public void handle(ByteBuf buf) throws Exception
+    {
+        EntityMap.rewrite( buf, con.clientEntityId, con.serverEntityId );
+        con.getServer().getCh().write( buf );
+    }
+
     @Override
     public void handle(Packet0KeepAlive alive) throws Exception
     {

proxy/src/main/java/net/md_5/bungee/netty/CipherCodec.java

@@ -33,9 +33,6 @@ public class CipherCodec extends ByteToByteCodec
         {
             heapOut = ctx.alloc().heapBuffer();
         }
-        System.out.println( "e) in: " + in );
-        System.out.println( "e) heapOut: " + heapOut );
-        System.out.println( "e) out: " + out );
         cipher( encrypt, in, heapOut );
         out.writeBytes( heapOut );
         heapOut.discardSomeReadBytes();
@@ -44,9 +41,6 @@ public class CipherCodec extends ByteToByteCodec
     @Override
     public void decode(ChannelHandlerContext ctx, ByteBuf in, ByteBuf out) throws Exception
     {
-        System.out.println( "d) in: " + in );
-        System.out.println( "d) heapOut: " + heapOut );
-        System.out.println( "d) out: " + out );
         cipher( decrypt, in, out );
     }
 

proxy/src/main/java/net/md_5/bungee/netty/HandlerBoss.java

@@ -51,17 +51,15 @@ public class HandlerBoss extends ChannelInboundMessageHandlerAdapter<ByteBuf>
             if ( packet != null )
             {
                 packet.handle( handler );
-            } else
-            {
-                handler.handle( msg );
             }
+            handler.handle( msg );
         }
     }
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception
     {
-        System.out.println( handler + "  " + Util.exception( cause ) );
+        cause.printStackTrace();
         if ( ctx.channel().isActive() )
         {
             ctx.close();

proxy/src/main/java/net/md_5/bungee/packet/Packet0KeepAlive.java

@@ -11,7 +11,7 @@ public class Packet0KeepAlive extends DefinedPacket
 
     public int id;
 
-    public Packet0KeepAlive(ByteBuf buf)
+    Packet0KeepAlive(ByteBuf buf)
     {
         super( 0x00, buf );
         id = readInt();

proxy/src/main/java/net/md_5/bungee/packet/Packet1Login.java

@@ -29,7 +29,7 @@ public class Packet1Login extends DefinedPacket
         writeByte( maxPlayers );
     }
 
-    public Packet1Login(ByteBuf buf)
+    Packet1Login(ByteBuf buf)
     {
         super( 0x01, buf );
         this.entityId = readInt();

proxy/src/main/java/net/md_5/bungee/packet/Packet2Handshake.java

@@ -23,7 +23,7 @@ public class Packet2Handshake extends DefinedPacket
         writeInt( port );
     }
 
-    public Packet2Handshake(ByteBuf buf)
+    Packet2Handshake(ByteBuf buf)
     {
         super( 0x02, buf );
         this.procolVersion = readByte();

proxy/src/main/java/net/md_5/bungee/packet/Packet3Chat.java

@@ -17,7 +17,7 @@ public class Packet3Chat extends DefinedPacket
         writeString( message );
     }
 
-    public Packet3Chat(ByteBuf buf)
+    Packet3Chat(ByteBuf buf)
     {
         super( 0x03, buf );
         this.message = readString();

proxy/src/main/java/net/md_5/bungee/packet/Packet9Respawn.java

@@ -27,7 +27,7 @@ public class Packet9Respawn extends DefinedPacket
         writeString( levelType );
     }
 
-    public Packet9Respawn(ByteBuf buf)
+    Packet9Respawn(ByteBuf buf)
     {
         super( 0x09, buf );
         this.dimension = readInt();

proxy/src/main/java/net/md_5/bungee/packet/PacketC9PlayerListItem.java

@@ -13,7 +13,7 @@ public class PacketC9PlayerListItem extends DefinedPacket
     public boolean online;
     public int ping;
 
-    public PacketC9PlayerListItem(ByteBuf buf)
+    PacketC9PlayerListItem(ByteBuf buf)
     {
         super( 0xC9, buf );
         username = readString();

proxy/src/main/java/net/md_5/bungee/packet/PacketCDClientStatus.java

@@ -22,7 +22,7 @@ public class PacketCDClientStatus extends DefinedPacket
         writeByte( payload );
     }
 
-    public PacketCDClientStatus(ByteBuf buf)
+    PacketCDClientStatus(ByteBuf buf)
     {
         super( 0xCD, buf );
     }

proxy/src/main/java/net/md_5/bungee/packet/PacketFAPluginMessage.java

@@ -21,7 +21,7 @@ public class PacketFAPluginMessage extends DefinedPacket
         this.data = data;
     }
 
-    public PacketFAPluginMessage(ByteBuf buf)
+    PacketFAPluginMessage(ByteBuf buf)
     {
         super( 0xFA, buf );
         this.tag = readString();

proxy/src/main/java/net/md_5/bungee/packet/PacketFCEncryptionResponse.java

@@ -26,7 +26,7 @@ public class PacketFCEncryptionResponse extends DefinedPacket
         writeArray( verifyToken );
     }
 
-    public PacketFCEncryptionResponse(ByteBuf buf)
+    PacketFCEncryptionResponse(ByteBuf buf)
     {
         super( 0xFC, buf );
         this.sharedSecret = readArray();

proxy/src/main/java/net/md_5/bungee/packet/PacketFDEncryptionRequest.java

@@ -24,7 +24,7 @@ public class PacketFDEncryptionRequest extends DefinedPacket
         this.verifyToken = verifyToken;
     }
 
-    public PacketFDEncryptionRequest(ByteBuf buf)
+    PacketFDEncryptionRequest(ByteBuf buf)
     {
         super( 0xFD, buf );
         serverId = readString();

proxy/src/main/java/net/md_5/bungee/packet/PacketFEPing.java

@@ -11,7 +11,7 @@ public class PacketFEPing extends DefinedPacket
 
     public byte version;
 
-    public PacketFEPing(ByteBuf buffer)
+    PacketFEPing(ByteBuf buffer)
     {
         super( 0xFE, buffer );
         version = readByte();

proxy/src/main/java/net/md_5/bungee/packet/PacketFFKick.java

@@ -17,7 +17,7 @@ public class PacketFFKick extends DefinedPacket
         writeString( message );
     }
 
-    public PacketFFKick(ByteBuf buf)
+    PacketFFKick(ByteBuf buf)
     {
         super( 0xFF, buf );
         this.message = readString();

proxy/src/main/java/net/md_5/bungee/packet/PacketHandler.java

@@ -6,11 +6,6 @@ import io.netty.channel.Channel;
 public abstract class PacketHandler
 {
 
-    private void nop(Object msg)
-    {
-        throw new UnsupportedOperationException( "No handler defined for packet " + msg.getClass() );
-    }
-
     public void connected(Channel channel) throws Exception
     {
     }
@@ -25,66 +20,53 @@ public abstract class PacketHandler
 
     public void handle(ByteBuf buf) throws Exception
     {
-        nop( buf );
     }
 
     public void handle(Packet0KeepAlive alive) throws Exception
     {
-        nop( alive );
     }
 
     public void handle(Packet1Login login) throws Exception
     {
-        nop( login );
     }
 
     public void handle(Packet2Handshake handshake) throws Exception
     {
-        nop( handshake );
     }
 
     public void handle(Packet3Chat chat) throws Exception
     {
-        nop( chat );
     }
 
     public void handle(Packet9Respawn respawn) throws Exception
     {
-        nop( respawn );
     }
 
     public void handle(PacketC9PlayerListItem playerList) throws Exception
     {
-        nop( playerList );
     }
 
     public void handle(PacketCDClientStatus clientStatus) throws Exception
     {
-        nop( clientStatus );
     }
 
     public void handle(PacketFAPluginMessage pluginMessage) throws Exception
     {
-        nop( pluginMessage );
     }
 
     public void handle(PacketFCEncryptionResponse encryptResponse) throws Exception
     {
-        nop( encryptResponse );
     }
 
     public void handle(PacketFDEncryptionRequest encryptRequest) throws Exception
     {
-        nop( encryptRequest );
     }
 
     public void handle(PacketFEPing ping) throws Exception
     {
-        nop( ping );
     }
 
     public void handle(PacketFFKick kick) throws Exception
     {
-        nop( kick );
     }
 }