Added new Server Properties and cleaned up Login Plugin Packets

- Added option for Modern Forwarding and BungeeGuard (for proxies that are connected to older servers)
- Made Modern, Bungeecord and Bungeeguard mutually exclusive
- Fixed PacketLoginInPluginMessaging, structure was incorrect
- Added `readUUID` in DataTypeIO

src/main/java/com/loohp/limbo/file/ServerProperties.java

@@ -1,26 +1,19 @@
 package com.loohp.limbo.file;
 
-import java.awt.image.BufferedImage;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.OutputStreamWriter;
-import java.io.PrintWriter;
-import java.nio.charset.StandardCharsets;
-import java.util.Map.Entry;
-import java.util.Optional;
-import java.util.Properties;
-
-import javax.imageio.ImageIO;
-
 import com.loohp.limbo.Limbo;
 import com.loohp.limbo.location.Location;
 import com.loohp.limbo.utils.GameMode;
 import com.loohp.limbo.utils.NamespacedKey;
 import com.loohp.limbo.world.World;
 
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.util.Map.Entry;
+import java.util.Optional;
+import java.util.Properties;
+
 public class ServerProperties {
 	
 	public static final String COMMENT = "For explaination of what each of the options does, please visit:\nhttps://github.com/LOOHP/Limbo/blob/master/src/main/resources/server.properties";
@@ -40,6 +33,9 @@ public class ServerProperties {
 	private String versionString;
 	private int protocol;
 	private boolean bungeecord;
+	private boolean velocityModern;
+	private boolean bungeeGuard;
+	private String[] forwardingSecrets;
 	private int viewDistance;
 	private double ticksPerSecond;
 	private boolean handshakeVerbose;
@@ -91,6 +87,27 @@ public class ServerProperties {
 		motdJson = prop.getProperty("motd");
 		versionString = prop.getProperty("version");
 		bungeecord = Boolean.parseBoolean(prop.getProperty("bungeecord"));
+		velocityModern = Boolean.parseBoolean(prop.getProperty("velocity-modern"));
+		bungeeGuard = Boolean.parseBoolean(prop.getProperty("bungee-guard"));
+		if (velocityModern || bungeeGuard) {
+			String forwardingSecretsStr = prop.getProperty("forwarding-secrets");
+			if (forwardingSecretsStr == null || forwardingSecretsStr.equals("")) {
+				Limbo.getInstance().getConsole().sendMessage("Velocity Modern Forwarding or BungeeGuard is enabled but no forwarding-secret was found!");
+				Limbo.getInstance().getConsole().sendMessage("Server will exit!");
+				System.exit(1);
+				return;
+			}
+			this.forwardingSecrets = forwardingSecretsStr.split(";");
+			if (bungeecord) {
+				Limbo.getInstance().getConsole().sendMessage("BungeeCord is enabled but so is Velocity Modern Forwarding or BungeeGuard, We will automatically disable BungeeCord forwarding because of this");
+				bungeecord = false;
+			}
+			if (velocityModern && bungeeGuard) {
+				Limbo.getInstance().getConsole().sendMessage("Both Velocity Modern Forwarding and BungeeGuard are enabled! Because of this we always prefer Modern Forwarding, disabling BungeeGuard");
+				bungeeGuard = false;
+			}
+		}
+
 		viewDistance = Integer.parseInt(prop.getProperty("view-distance"));
 		ticksPerSecond = Double.parseDouble(prop.getProperty("ticks-per-second"));
 		handshakeVerbose = Boolean.parseBoolean(prop.getProperty("handshake-verbose"));
@@ -123,6 +140,18 @@ public class ServerProperties {
 		return bungeecord;
 	}
 
+	public boolean isVelocityModern() {
+		return velocityModern;
+	}
+
+	public boolean isBungeeGuard() {
+		return bungeeGuard;
+	}
+
+	public String[] getForwardingSecrets() {
+		return forwardingSecrets;
+	}
+
 	public Optional<BufferedImage> getFavicon() {
 		return favicon;
 	}

src/main/java/com/loohp/limbo/server/packets/PacketLoginInPluginMessaging.java

@@ -1,39 +1,39 @@
 package com.loohp.limbo.server.packets;
 
+import com.loohp.limbo.utils.DataTypeIO;
+
 import java.io.DataInputStream;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-
-import com.loohp.limbo.utils.DataTypeIO;
-import com.loohp.limbo.utils.NamespacedKey;
 
 public class PacketLoginInPluginMessaging extends PacketIn {
 
 	private int messageId;
-	private NamespacedKey channel;
+	private boolean successful;
-	private byte[] data;
+	private byte[] data = null;
 
-	public PacketLoginInPluginMessaging(int messageId, NamespacedKey channel, byte[] data) {
+	public PacketLoginInPluginMessaging(int messageId, boolean successful, byte[] data) {
 		this.messageId = messageId;
-		this.channel = channel;
 		this.data = data;
 	}
 	
 	public PacketLoginInPluginMessaging(DataInputStream in, int packetLength, int packetId) throws IOException {
 		messageId = DataTypeIO.readVarInt(in);
-		String rawChannel = DataTypeIO.readString(in, StandardCharsets.UTF_8);
+		successful = in.readBoolean();
-		channel = new NamespacedKey(rawChannel);
+		if (successful) {
-		int dataLength = packetLength - DataTypeIO.getVarIntLength(packetId) - DataTypeIO.getVarIntLength(messageId) - DataTypeIO.getStringLength(rawChannel, StandardCharsets.UTF_8);
+			int dataLength = packetLength - DataTypeIO.getVarIntLength(packetId) - DataTypeIO.getVarIntLength(messageId) - 1;
-		data = new byte[dataLength];
+			if (dataLength != 0) {
-		in.read(data);
+				data = new byte[dataLength];
+				in.readFully(data);
+			}
+		}
 	}
 	
 	public int getMessageId() {
 		return messageId;
 	}
 
-	public NamespacedKey getChannel() {
+	public boolean isSuccessful() {
-		return channel;
+		return successful;
 	}
 
 	public byte[] getData() {

src/main/java/com/loohp/limbo/server/packets/PacketLoginOutPluginMessaging.java

@@ -1,19 +1,23 @@
 package com.loohp.limbo.server.packets;
 
+import com.loohp.limbo.utils.DataTypeIO;
+import com.loohp.limbo.utils.NamespacedKey;
+
 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
-import com.loohp.limbo.utils.DataTypeIO;
-import com.loohp.limbo.utils.NamespacedKey;
-
 public class PacketLoginOutPluginMessaging extends PacketOut {
 
 	private int messageId;
 	private NamespacedKey channel;
 	private byte[] data;
 
+	public PacketLoginOutPluginMessaging(int messageId, NamespacedKey channel) {
+		this(messageId, channel, null);
+	}
+
 	public PacketLoginOutPluginMessaging(int messageId, NamespacedKey channel, byte[] data) {
 		this.messageId = messageId;
 		this.channel = channel;
@@ -40,7 +44,9 @@ public class PacketLoginOutPluginMessaging extends PacketOut {
 		output.writeByte(Packet.getLoginOut().get(getClass()));
 		DataTypeIO.writeVarInt(output, messageId);
 		DataTypeIO.writeString(output, channel.toString(), StandardCharsets.UTF_8);
-		output.write(data);
+		if (data != null) {
+			output.write(data);
+		}
 		
 		return buffer.toByteArray();
 	}

src/main/java/com/loohp/limbo/utils/DataTypeIO.java

@@ -23,6 +23,10 @@ public class DataTypeIO {
 		out.writeLong(uuid.getMostSignificantBits());
 		out.writeLong(uuid.getLeastSignificantBits());
 	}
+
+	public static UUID readUUID(DataInputStream in) throws IOException {
+		return new UUID(in.readLong(), in.readLong());
+	}
 	
 	public static void writeCompoundTag(DataOutputStream out, CompoundTag tag) throws IOException {
 		ByteArrayOutputStream buffer = new ByteArrayOutputStream();

src/main/resources/mapping.json

@@ -9,7 +9,7 @@
   "LoginOut": {
     "PacketLoginOutLoginSuccess": "0x02",
     "PacketLoginOutDisconnect": "0x00",
-    "PacketLoginOutPluginMessaging": "0x04",
+    "PacketLoginOutPluginMessaging": "0x04"
   },
   "PlayIn": {
     "0x0F": "PacketPlayInKeepAlive",

src/main/resources/server.properties

@@ -7,9 +7,21 @@ server-port=30000
 #Server ip, localhost for local access only
 server-ip=0.0.0.0
 
-#Whether this is server is behind a bungeecord proxy
+#Whether this server is behind a bungeecord proxy
+#Mutually exclusive with velocity-modern and bungee-guard
 bungeecord=false
 
+#Whether this server is behind a velocity proxy with modern player forwarding
+#Mutually exclusive with bungeecord and bungee-guard
+velocity-modern=false
+
+#Whether this server is behind a bungeecord proxy with BungeeGuard installed (velocity can do this too for <1.13)
+#Mutually exclusive with bungeecord and velocity-modern
+bungee-guard=false
+
+#For Velocity Modern Forwarding or BungeeGuard a list (separated by `;`) of valid secrets
+forwarding-secrets=
+
 #World Name and the Schematic file containing map
 level-name=world;spawn.schem