Progress towards a server connection pipeline.

src/main/java/io/minimum/minecraft/velocity/Velocity.java

@@ -1,34 +1,15 @@
 package io.minimum.minecraft.velocity;
 
-import io.minimum.minecraft.velocity.protocol.ProtocolConstants;
-import io.minimum.minecraft.velocity.protocol.netty.*;
-import io.minimum.minecraft.velocity.proxy.InboundMinecraftConnection;
-import io.minimum.minecraft.velocity.proxy.MinecraftClientSessionHandler;
-import io.netty.bootstrap.ServerBootstrap;
-import io.netty.channel.Channel;
-import io.netty.channel.ChannelInitializer;
-import io.netty.channel.nio.NioEventLoopGroup;
-import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.minimum.minecraft.velocity.proxy.VelocityServer;
 
 public class Velocity {
     public static void main(String... args) throws InterruptedException {
-        new ServerBootstrap()
-                .channel(NioServerSocketChannel.class)
-                .group(new NioEventLoopGroup())
-                .childHandler(new ChannelInitializer<Channel>() {
-                    @Override
-                    protected void initChannel(Channel ch) throws Exception {
-                        ch.attr(InboundMinecraftConnection.CONNECTION).set(new InboundMinecraftConnection(ch));
-                        ch.pipeline().addLast("legacy-ping-decode", new LegacyPingDecoder());
-                        ch.pipeline().addLast("frame-decoder", new MinecraftVarintFrameDecoder());
-                        ch.pipeline().addLast("legacy-ping-encode", new LegacyPingEncoder());
-                        ch.pipeline().addLast("frame-encoder", new MinecraftVarintLengthEncoder());
-                        ch.pipeline().addLast("minecraft-decoder", new MinecraftDecoder(ProtocolConstants.Direction.TO_SERVER));
-                        ch.pipeline().addLast("minecraft-encoder", new MinecraftEncoder(ProtocolConstants.Direction.TO_CLIENT));
-                        ch.pipeline().addLast("handler", new MinecraftClientSessionHandler());
+        VelocityServer server = new VelocityServer();
+        server.initialize();
+
+        while (true) {
+            // temporary until jline is added.
+            Thread.sleep(999999);
         }
-                })
-                .bind(26671)
-                .await();
     }
 }

src/main/java/io/minimum/minecraft/velocity/protocol/StateRegistry.java

@@ -27,7 +27,10 @@ public enum StateRegistry {
     LOGIN {
         {
             TO_SERVER.register(0x00, ServerLogin.class, ServerLogin::new);
+
             TO_CLIENT.register(0x00, Disconnect.class, Disconnect::new);
+            // Encryption Success will follow once Mojang auth/encryption is done
+            TO_CLIENT.register(0x02, ServerLoginSuccess.class, ServerLogin::new);
         }
     };
 

src/main/java/io/minimum/minecraft/velocity/protocol/netty/LegacyPingEncoder.java

@@ -2,16 +2,23 @@ package io.minimum.minecraft.velocity.protocol.netty;
 
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
+import io.minimum.minecraft.velocity.protocol.packets.LegacyPing;
 import io.minimum.minecraft.velocity.protocol.packets.LegacyPingResponse;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufUtil;
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
 
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
+@ChannelHandler.Sharable
 public class LegacyPingEncoder extends MessageToByteEncoder<LegacyPingResponse> {
+    public static final LegacyPingEncoder INSTANCE = new LegacyPingEncoder();
+
+    private LegacyPingEncoder() {}
+
     @Override
     protected void encode(ChannelHandlerContext ctx, LegacyPingResponse msg, ByteBuf out) throws Exception {
         out.writeByte(0xff);

src/main/java/io/minimum/minecraft/velocity/protocol/netty/MinecraftPipelineUtils.java

@@ -0,0 +1,15 @@
+package io.minimum.minecraft.velocity.protocol.netty;
+
+import io.minimum.minecraft.velocity.protocol.ProtocolConstants;
+import io.netty.channel.Channel;
+
+public class MinecraftPipelineUtils {
+    public static void strapPipeline(Channel ch) {
+        ch.pipeline().addLast("legacy-ping-decode", new LegacyPingDecoder());
+        ch.pipeline().addLast("frame-decoder", new MinecraftVarintFrameDecoder());
+        ch.pipeline().addLast("legacy-ping-encode", LegacyPingEncoder.INSTANCE);
+        ch.pipeline().addLast("frame-encoder", MinecraftVarintLengthEncoder.INSTANCE);
+        ch.pipeline().addLast("minecraft-decoder", new MinecraftDecoder(ProtocolConstants.Direction.TO_SERVER));
+        ch.pipeline().addLast("minecraft-encoder", new MinecraftEncoder(ProtocolConstants.Direction.TO_CLIENT));
+    }
+}

src/main/java/io/minimum/minecraft/velocity/protocol/netty/MinecraftVarintLengthEncoder.java

@@ -2,10 +2,16 @@ package io.minimum.minecraft.velocity.protocol.netty;
 
 import io.minimum.minecraft.velocity.protocol.ProtocolUtils;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
 
+@ChannelHandler.Sharable
 public class MinecraftVarintLengthEncoder extends MessageToByteEncoder<ByteBuf> {
+    public static final MinecraftVarintLengthEncoder INSTANCE = new MinecraftVarintLengthEncoder();
+
+    private MinecraftVarintLengthEncoder() { }
+
     @Override
     protected void encode(ChannelHandlerContext ctx, ByteBuf msg, ByteBuf out) throws Exception {
         ProtocolUtils.writeVarInt(out, msg.readableBytes());

src/main/java/io/minimum/minecraft/velocity/protocol/packets/ServerLoginSuccess.java

@@ -0,0 +1,49 @@
+package io.minimum.minecraft.velocity.protocol.packets;
+
+import io.minimum.minecraft.velocity.protocol.MinecraftPacket;
+import io.minimum.minecraft.velocity.protocol.ProtocolConstants;
+import io.minimum.minecraft.velocity.protocol.ProtocolUtils;
+import io.netty.buffer.ByteBuf;
+
+import java.util.UUID;
+
+public class ServerLoginSuccess implements MinecraftPacket {
+    private UUID uuid;
+    private String username;
+
+    public UUID getUuid() {
+        return uuid;
+    }
+
+    public void setUuid(UUID uuid) {
+        this.uuid = uuid;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    @Override
+    public String toString() {
+        return "ServerLoginSuccess{" +
+                "uuid=" + uuid +
+                ", username='" + username + '\'' +
+                '}';
+    }
+
+    @Override
+    public void decode(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion) {
+        uuid = UUID.fromString(ProtocolUtils.readString(buf, 36));
+        username = ProtocolUtils.readString(buf, 16);
+    }
+
+    @Override
+    public void encode(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion) {
+        ProtocolUtils.writeString(buf, uuid.toString());
+        ProtocolUtils.writeString(buf, username);
+    }
+}

src/main/java/io/minimum/minecraft/velocity/proxy/ConnectedPlayer.java

@@ -0,0 +1,34 @@
+package io.minimum.minecraft.velocity.proxy;
+
+import io.minimum.minecraft.velocity.proxy.server.ServerConnection;
+
+import java.util.UUID;
+
+public class ConnectedPlayer {
+    private final String username;
+    private final UUID uniqueId;
+    private final InboundMinecraftConnection connection;
+    private ServerConnection connectedServer;
+
+    public ConnectedPlayer(String username, UUID uniqueId, InboundMinecraftConnection connection) {
+        this.username = username;
+        this.uniqueId = uniqueId;
+        this.connection = connection;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public UUID getUniqueId() {
+        return uniqueId;
+    }
+
+    public InboundMinecraftConnection getConnection() {
+        return connection;
+    }
+
+    public ServerConnection getConnectedServer() {
+        return connectedServer;
+    }
+}

src/main/java/io/minimum/minecraft/velocity/proxy/InboundMinecraftConnection.java

@@ -66,10 +66,12 @@ public class InboundMinecraftConnection {
                 this.setStatus(StateRegistry.STATUS);
                 this.sessionHandler = new StatusSessionHandler(this);
                 break;
-            default:
+            case 2:
                 this.setStatus(StateRegistry.LOGIN);
                 this.sessionHandler = new LoginSessionHandler(this);
                 break;
+            default:
+                throw new IllegalArgumentException("Invalid state " + handshake.getNextStatus());
         }
     }
 
@@ -83,4 +85,8 @@ public class InboundMinecraftConnection {
         channel.pipeline().get(MinecraftEncoder.class).setState(state);
         channel.pipeline().get(MinecraftDecoder.class).setState(state);
     }
+
+    public void teardown() {
+        closed = true;
+    }
 }

src/main/java/io/minimum/minecraft/velocity/proxy/MinecraftClientSessionHandler.java

@@ -52,6 +52,12 @@ public class MinecraftClientSessionHandler extends ChannelInboundHandlerAdapter
         }
     }
 
+    @Override
+    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
+        InboundMinecraftConnection connection = ctx.channel().attr(InboundMinecraftConnection.CONNECTION).get();
+        connection.teardown();
+    }
+
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         cause.printStackTrace();

src/main/java/io/minimum/minecraft/velocity/proxy/MinecraftSessionHandler.java

@@ -9,4 +9,8 @@ public interface MinecraftSessionHandler {
     default void handleUnknown(ByteBuf buf) {
         // No-op: we'll release the buffer later.
     }
+
+    default void connectionClosed() {
+
+    }
 }

src/main/java/io/minimum/minecraft/velocity/proxy/VelocityServer.java

@@ -0,0 +1,54 @@
+package io.minimum.minecraft.velocity.proxy;
+
+import io.minimum.minecraft.velocity.protocol.ProtocolConstants;
+import io.minimum.minecraft.velocity.protocol.netty.*;
+import io.minimum.minecraft.velocity.proxy.server.ServerConnection;
+import io.netty.bootstrap.Bootstrap;
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.*;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.channel.socket.nio.NioSocketChannel;
+
+public class VelocityServer {
+    private EventLoopGroup bossGroup;
+    private EventLoopGroup childGroup;
+
+    public VelocityServer() {
+
+    }
+
+    public void initialize() {
+        bossGroup = new NioEventLoopGroup();
+        childGroup = new NioEventLoopGroup();
+        new ServerBootstrap()
+                .channel(NioServerSocketChannel.class)
+                .group(bossGroup, childGroup)
+                .childHandler(new ChannelInitializer<Channel>() {
+                    @Override
+                    protected void initChannel(Channel ch) throws Exception {
+                        ch.attr(InboundMinecraftConnection.CONNECTION).set(new InboundMinecraftConnection(ch));
+                        MinecraftPipelineUtils.strapPipeline(ch);
+                        ch.pipeline().addLast("handler", new MinecraftClientSessionHandler());
+                    }
+                })
+                .bind(26671)
+                .addListener(new ChannelFutureListener() {
+                    @Override
+                    public void operationComplete(ChannelFuture future) throws Exception {
+                        if (future.isSuccess()) {
+                            System.out.println("Listening on " + future.channel().localAddress());
+                        } else {
+                            System.out.println("Can't bind to " + future.channel().localAddress());
+                            future.cause().printStackTrace();
+                        }
+                    }
+                });
+    }
+
+    Bootstrap initializeGenericBootstrap() {
+        return new Bootstrap()
+                .channel(NioSocketChannel.class)
+                .group(childGroup);
+    }
+}

src/main/java/io/minimum/minecraft/velocity/proxy/handler/LoginSessionHandler.java

@@ -2,12 +2,13 @@ package io.minimum.minecraft.velocity.proxy.handler;
 
 import com.google.common.base.Preconditions;
 import io.minimum.minecraft.velocity.protocol.MinecraftPacket;
-import io.minimum.minecraft.velocity.protocol.packets.Disconnect;
 import io.minimum.minecraft.velocity.protocol.packets.ServerLogin;
+import io.minimum.minecraft.velocity.protocol.packets.ServerLoginSuccess;
 import io.minimum.minecraft.velocity.proxy.InboundMinecraftConnection;
 import io.minimum.minecraft.velocity.proxy.MinecraftSessionHandler;
-import net.kyori.text.TextComponent;
-import net.kyori.text.serializer.ComponentSerializers;
+
+import java.nio.charset.StandardCharsets;
+import java.util.UUID;
 
 public class LoginSessionHandler implements MinecraftSessionHandler {
     private final InboundMinecraftConnection connection;
@@ -20,9 +21,15 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
     public void handle(MinecraftPacket packet) {
         Preconditions.checkArgument(packet instanceof ServerLogin, "Expected a ServerLogin packet, not " + packet.getClass().getName());
 
-        // Disconnect with test message
-        Disconnect disconnect = new Disconnect();
-        disconnect.setReason(ComponentSerializers.JSON.serialize(TextComponent.of("Hi there!")));
-        connection.closeWith(disconnect);
+        String username = ((ServerLogin) packet).getUsername();
+        ServerLoginSuccess success = new ServerLoginSuccess();
+        success.setUsername(username);
+        success.setUuid(generateOfflinePlayerUuid(username));
+
+        connection.write(success);
+    }
+
+    private static UUID generateOfflinePlayerUuid(String username) {
+        return UUID.nameUUIDFromBytes(username.getBytes(StandardCharsets.UTF_8));
     }
 }

src/main/java/io/minimum/minecraft/velocity/proxy/handler/PlaySessionHandler.java

@@ -0,0 +1,17 @@
+package io.minimum.minecraft.velocity.proxy.handler;
+
+import io.minimum.minecraft.velocity.protocol.MinecraftPacket;
+import io.minimum.minecraft.velocity.proxy.MinecraftSessionHandler;
+import io.netty.buffer.ByteBuf;
+
+public class PlaySessionHandler implements MinecraftSessionHandler {
+    @Override
+    public void handle(MinecraftPacket packet) {
+
+    }
+
+    @Override
+    public void handleUnknown(ByteBuf buf) {
+
+    }
+}

src/main/java/io/minimum/minecraft/velocity/proxy/server/ServerConnection.java

@@ -0,0 +1,19 @@
+package io.minimum.minecraft.velocity.proxy.server;
+
+import io.minimum.minecraft.velocity.protocol.StateRegistry;
+import io.minimum.minecraft.velocity.proxy.ConnectedPlayer;
+import io.netty.channel.Channel;
+
+public class ServerConnection {
+    private final Channel remoteServer;
+    private final ConnectedPlayer proxyPlayer;
+    private StateRegistry registry;
+
+    public ServerConnection(Channel remoteServer, ConnectedPlayer proxyPlayer) {
+        this.remoteServer = remoteServer;
+        this.proxyPlayer = proxyPlayer;
+        this.registry = StateRegistry.HANDSHAKE;
+    }
+
+
+}