kick for invalid version, use disconnect after kick packet, change logging level back to info, fix problem with compression on and encryption off.

build.gradle

@@ -22,7 +22,7 @@ sourceSets {
             srcDir 'src/autogenerated/java'
         }
     }
-    generation {
+    generators {
         java {
             srcDir 'src/generators/java'
         }

src/main/java/net/minestom/server/MinecraftServer.java

@@ -142,7 +142,7 @@ public class MinecraftServer {
 
         // Registry
         try {
-            ResourceGatherer.ensureResourcesArePresent("1.15.2", null); // TODO: provide a way to give a path override, probably via launch arguments?
+            ResourceGatherer.ensureResourcesArePresent("1.16.1", null); // TODO: provide a way to give a path override, probably via launch arguments?
         } catch (IOException e) {
             LOGGER.error("An error happened during resource gathering. Minestom will attempt to load anyway, but things may not work, and crashes can happen.", e);
         }

src/main/java/net/minestom/server/network/packet/client/handshake/HandshakePacket.java

@@ -1,9 +1,13 @@
 package net.minestom.server.network.packet.client.handshake;
 
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.chat.ChatColor;
+import net.minestom.server.chat.ColoredText;
 import net.minestom.server.network.ConnectionManager;
 import net.minestom.server.network.ConnectionState;
 import net.minestom.server.network.packet.PacketReader;
 import net.minestom.server.network.packet.client.ClientPreplayPacket;
+import net.minestom.server.network.packet.server.login.LoginDisconnect;
 import net.minestom.server.network.player.PlayerConnection;
 
 public class HandshakePacket implements ClientPreplayPacket {
@@ -29,6 +33,10 @@ public class HandshakePacket implements ClientPreplayPacket {
                 break;
             case 2:
                 connection.setConnectionState(ConnectionState.LOGIN);
+                if (protocolVersion != MinecraftServer.PROTOCOL_VERSION) {
+                    connection.sendPacket(new LoginDisconnect(ColoredText.of(ChatColor.RED, "Invalid Version").toString()));
+                    connection.disconnect();
+                }
                 break;
             default:
                 // Unexpected error

src/main/java/net/minestom/server/network/packet/client/login/LoginStartPacket.java

@@ -28,6 +28,7 @@ public class LoginStartPacket implements ClientPreplayPacket {
 				//toLowerCase b/c there is a hack to change caps in your name
 				if (pl.getUsername().toLowerCase().equals(username.toLowerCase())) {
 					connection.sendPacket(new LoginDisconnect(ColoredText.of(ChatColor.RED, "You are already on this server").toString()));
+					connection.disconnect();
 					return;
 				}
 			}

src/main/java/net/minestom/server/network/player/NettyPlayerConnection.java

@@ -2,12 +2,10 @@ package net.minestom.server.network.player;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelHandlerContext;
 import lombok.Getter;
 import net.minestom.server.extras.mojangAuth.Decrypter;
 import net.minestom.server.extras.mojangAuth.Encrypter;
 import net.minestom.server.extras.mojangAuth.MojangCrypt;
-import io.netty.channel.ChannelPipeline;
 import io.netty.channel.socket.SocketChannel;
 import net.minestom.server.network.netty.codec.PacketCompressor;
 import net.minestom.server.network.packet.server.ServerPacket;
@@ -25,6 +23,8 @@ public class NettyPlayerConnection extends PlayerConnection {
 	private final SocketChannel channel;
 	@Getter
 	private boolean encrypted = false;
+	@Getter
+	private boolean compressed = false;
 
 	public NettyPlayerConnection(SocketChannel channel) {
 		super();
@@ -39,6 +39,7 @@ public class NettyPlayerConnection extends PlayerConnection {
 
 	@Override
     public void enableCompression(int threshold) {
+		this.compressed = true;
         sendPacket(new SetCompressionPacket(threshold));
         channel.pipeline().addAfter("framer", "compressor", new PacketCompressor(threshold));
     }
@@ -46,7 +47,7 @@ public class NettyPlayerConnection extends PlayerConnection {
     @Override
 	public void sendPacket(ByteBuf buffer, boolean copy) {
 		//System.out.println(getConnectionState() + " out");
-		if (encrypted && copy) {
+		if ((encrypted || compressed) && copy) {
 			buffer = buffer.copy();
 			buffer.retain();
 			channel.writeAndFlush(buffer);
@@ -58,7 +59,7 @@ public class NettyPlayerConnection extends PlayerConnection {
 
 	@Override
 	public void writePacket(ByteBuf buffer, boolean copy) {
-		if (encrypted && copy) {
+		if ((encrypted || compressed) && copy) {
 			buffer = buffer.copy();
 			buffer.retain();
 			channel.write(buffer);

src/main/resources/log4j2.xml

@@ -8,7 +8,7 @@
 
     <Loggers>
         <Root level="trace">
-            <AppenderRef ref="STDOUT" level="debug"/>
+            <AppenderRef ref="STDOUT" level="info"/>
         </Root>
     </Loggers>
 </Configuration>