Fix Floodgate prefix with ProtocolLib

bukkit/pom.xml

@@ -376,8 +376,8 @@
             <groupId>io.netty</groupId>
             <artifactId>netty-transport</artifactId>
             <version>${nettyVersion}</version>
-            <scope>test</scope>
-        </dependency>        
+            <scope>provided</scope>
+        </dependency>
 
         <dependency>
             <groupId>io.netty</groupId>

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/FastLoginBukkit.java

@@ -30,7 +30,6 @@
 import com.github.games647.fastlogin.bukkit.command.PremiumCommand;
 import com.github.games647.fastlogin.bukkit.listener.ConnectionListener;
 import com.github.games647.fastlogin.bukkit.listener.PaperCacheListener;
-import com.github.games647.fastlogin.bukkit.listener.protocollib.ManualNameChange;
 import com.github.games647.fastlogin.bukkit.listener.protocollib.ProtocolLibListener;
 import com.github.games647.fastlogin.bukkit.listener.protocollib.SkinApplyListener;
 import com.github.games647.fastlogin.bukkit.listener.protocolsupport.ProtocolSupportListener;
@@ -119,10 +118,6 @@ public void onEnable() {
             } else if (pluginManager.isPluginEnabled("ProtocolLib")) {
                 ProtocolLibListener.register(this, core.getAntiBot(), core.getConfig().getBoolean("verifyClientKeys"));
 
-                if (isPluginInstalled("floodgate")) {
-                    printFloodgateWarning();
-                }
-
                 //if server is using paper - we need to set the skin at pre login anyway, so no need for this listener
                 if (!PaperLib.isPaper() && getConfig().getBoolean("forwardSkin")) {
                     pluginManager.registerEvents(new SkinApplyListener(this), this);
@@ -152,23 +147,6 @@ public void onEnable() {
             premiumPlaceholder = new PremiumPlaceholder(this);
             premiumPlaceholder.register();
         }
-
-        dependencyWarnings();
-    }
-
-    private void printFloodgateWarning() {
-        if (getConfig().getBoolean("floodgatePrefixWorkaround")) {
-            ManualNameChange.register(this, floodgateService);
-            logger.info("Floodgate prefix injection workaround has been enabled.");
-            logger.info("If you have problems joining the server, try disabling it in the configuration.");
-        } else {
-            logger.warn("We have detected that you are running FastLogin alongside Floodgate and ProtocolLib.");
-            logger.warn("Currently there is an issue with FastLogin that prevents Floodgate name prefixes from "
-                + "showing up when it is together used with ProtocolLib.");
-            logger.warn("If you would like to use Floodgate name prefixes, you can enable an experimental "
-                + "workaround by changing the value 'floodgatePrefixWorkaround' to true in config.yml.");
-            logger.warn("For more information visit https://github.com/games647/FastLogin/issues/493");
-        }
     }
 
     private boolean initializeFloodgate() {
@@ -326,18 +304,4 @@ public BedrockService<?> getBedrockService() {
         }
         return geyserService;
     }
-
-    /**
-     * Send warning messages to log if incompatible plugins are used
-     */
-    private void dependencyWarnings() {
-        if (isPluginInstalled("floodgate-bukkit")) {
-            logger.warn("We have detected that you are running Floodgate 1.0 which is not supported by the Bukkit "
-                    + "version of FastLogin.");
-            logger.warn("If you would like to use FastLogin with Floodgate, you can download development builds of "
-                    + "Floodgate 2.0 from https://ci.opencollab.dev/job/GeyserMC/job/Floodgate/job/dev%252F2.0/");
-            logger.warn("Don't forget to update Geyser to a supported version as well from "
-                    + "https://ci.opencollab.dev/job/GeyserMC/job/Geyser/job/floodgate-2.0/");
-        }
-    }
 }

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/listener/protocollib/ProtocolLibListener.java

@@ -30,6 +30,8 @@
 import com.comphenix.protocol.events.PacketAdapter;
 import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.injector.PacketFilterManager;
+import com.comphenix.protocol.injector.player.PlayerInjectionHandler;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
 import com.comphenix.protocol.wrappers.BukkitConverters;
@@ -42,6 +44,7 @@
 import com.github.games647.fastlogin.core.antibot.AntiBotService.Action;
 import com.mojang.datafixers.util.Either;
 
+import java.lang.reflect.Field;
 import java.net.InetSocketAddress;
 import java.security.InvalidKeyException;
 import java.security.KeyPair;
@@ -58,15 +61,20 @@
 import javax.crypto.IllegalBlockSizeException;
 import javax.crypto.NoSuchPaddingException;
 
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandler;
+import io.netty.util.AttributeKey;
 import lombok.val;
 import org.bukkit.entity.Player;
+import org.geysermc.floodgate.api.player.FloodgatePlayer;
 
 import static com.comphenix.protocol.PacketType.Login.Client.ENCRYPTION_BEGIN;
 import static com.comphenix.protocol.PacketType.Login.Client.START;
 
 public class ProtocolLibListener extends PacketAdapter {
 
     private final FastLoginBukkit plugin;
+    private final PlayerInjectionHandler handler;
 
     //just create a new once on plugin enable. This used for verify token generation
     private final SecureRandom random = new SecureRandom();
@@ -85,6 +93,7 @@ public ProtocolLibListener(FastLoginBukkit plugin, AntiBotService antiBotService
         this.plugin = plugin;
         this.antiBotService = antiBotService;
         this.verifyClientKeys = verifyClientKeys;
+        this.handler = getHandler();
     }
 
     public static void register(FastLoginBukkit plugin, AntiBotService antiBotService, boolean verifyClientKeys) {
@@ -109,6 +118,15 @@ public void onPacketReceiving(PacketEvent packetEvent) {
         Player sender = packetEvent.getPlayer();
         PacketType packetType = packetEvent.getPacketType();
         if (packetType == START) {
+
+            if (plugin.getFloodgateService() != null) {
+                boolean success = processFloodgateTasks(packetEvent);
+                // don't continue execution if the player was kicked by Floodgate
+                if (!success) {
+                    return;
+                }
+            }
+
             PacketContainer packet = packetEvent.getPacket();
 
             InetSocketAddress address = sender.getAddress();
@@ -201,11 +219,6 @@ private void onLoginStart(PacketEvent packetEvent, Player player, String usernam
         //remove old data every time on a new login in order to keep the session only for one person
         plugin.removeSession(player.getAddress());
 
-        if (packetEvent.getPacket().getMeta("original_name").isPresent()) {
-            //username has been injected by ManualNameChange.java
-            username = (String) packetEvent.getPacket().getMeta("original_name").get();
-        }
-
         PacketContainer packet = packetEvent.getPacket();
         val profileKey = packet.getOptionals(BukkitConverters.getWrappedPublicKeyDataConverter())
                 .optionRead(0);
@@ -254,4 +267,65 @@ private String getUsername(PacketContainer packet) {
         //player.getName() won't work at this state
         return profile.getName();
     }
+
+    private static PlayerInjectionHandler getHandler() {
+        try {
+            PacketFilterManager manager = (PacketFilterManager) ProtocolLibrary.getProtocolManager();
+            Field f = manager.getClass().getDeclaredField("playerInjectionHandler");
+            f.setAccessible(true);
+            PlayerInjectionHandler handler = (PlayerInjectionHandler) f.get(manager);
+            f.setAccessible(false);
+            return handler;
+        } catch (NoSuchFieldException e) {
+            throw new RuntimeException(e);
+        } catch (IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private FloodgatePlayer getFloodgatePlayer(Player player) {
+        Channel channel = handler.getChannel(player);
+        AttributeKey<FloodgatePlayer> floodgateAttribute = AttributeKey.valueOf("floodgate-player");
+        return channel.attr(floodgateAttribute).get();
+    }
+
+    /**
+     * Reimplementation of the tasks injected Floodgate in ProtocolLib that are not run due to a bug
+     * @see <a href="https://github.com/GeyserMC/Floodgate/issues/143">Issue Floodgate#143</a>
+     * @see <a href="https://github.com/GeyserMC/Floodgate/blob/5d5713ed9e9eeab0f4abdaa9cf5cd8619dc1909b/spigot/src/main/java/org/geysermc/floodgate/addon/data/SpigotDataHandler.java#L121-L175">Floodgate/SpigotDataHandler</a>
+     * @param packetEvent the PacketEvent that won't be processed by Floodgate
+     * @return false if the player was kicked
+     */
+    private boolean processFloodgateTasks(PacketEvent packetEvent) {
+        PacketContainer packet = packetEvent.getPacket();
+        Player player = packetEvent.getPlayer();
+        FloodgatePlayer floodgatePlayer = getFloodgatePlayer(player);
+        if (floodgatePlayer == null) {
+            return true;
+        }
+
+        // kick the player, if necessary
+        Channel channel = handler.getChannel(packetEvent.getPlayer());
+        AttributeKey<String> kickMessageAttribute = AttributeKey.valueOf("floodgate-kick-message");
+        String kickMessage = channel.attr(kickMessageAttribute).get();
+        if (kickMessage != null) {
+            player.kickPlayer(kickMessage);
+            return false;
+        }
+
+        // add prefix
+        String username = floodgatePlayer.getCorrectUsername();
+        if (packet.getGameProfiles().size() > 0) {
+            packet.getGameProfiles().write(0,
+                    new WrappedGameProfile(floodgatePlayer.getCorrectUniqueId(), username));
+        } else {
+            packet.getStrings().write(0, username);
+        }
+
+        // remove real Floodgate data handler
+        ChannelHandler floodgateHandler = channel.pipeline().get("floodgate_data_handler");
+        channel.pipeline().remove(floodgateHandler);
+
+        return true;
+    }
 }

checkstyle.xml

@@ -101,6 +101,7 @@
   <module name="LineLength">
     <property name="max" value="120"/>
     <property name="fileExtensions" value="java"/>
+    <property name="ignorePattern" value="^ *\* *@see.+$"/>
   </module>
 
   <!-- Checks for whitespace                               -->

core/src/main/java/com/github/games647/fastlogin/core/hooks/bedrock/FloodgateService.java

@@ -99,23 +99,11 @@ public boolean performChecks(String username, LoginSource source) {
      * The FloodgateApi does not support querying players by name, so this function
      * iterates over every online FloodgatePlayer and checks if the requested
      * username can be found
-     * <br>
-     * <i>Falls back to non-prefixed name checks, if ProtocolLib is installed</i>
      *
      * @param prefixedUsername the name of the player with the prefix appended
      * @return FloodgatePlayer if found, null otherwise
      */
     public FloodgatePlayer getBedrockPlayer(String prefixedUsername) {
-        //prefixes are broken with ProtocolLib, so fall back to name checks without prefixes
-        //this should be removed if #493 gets fixed
-        if (core.getPlugin().isPluginInstalled("ProtocolLib")) {
-            for (FloodgatePlayer floodgatePlayer : floodgate.getPlayers()) {
-                if (floodgatePlayer.getUsername().equals(prefixedUsername)) {
-                    return floodgatePlayer;
-                }
-            }
-            return null;
-        }
         for (FloodgatePlayer floodgatePlayer : floodgate.getPlayers()) {
             if (floodgatePlayer.getCorrectUsername().equals(prefixedUsername)) {
                 return floodgatePlayer;

core/src/main/resources/config.yml

@@ -236,8 +236,6 @@ autoLoginFloodgate: false
 #
 # To prevent conflicts from two different players having the same name, it is highly recommended using a
 #    'username-prefix' in floodgate/config.yml
-# Note: 'username-prefix' is currently broken when used with FastLogin and ProtocolLib.
-# A solution to this is to enable 'floodgatePrefixWorkaround' below.
 #
 # Possible values:
 #   false: Kick Bedrock players, if they are using an existing Premium Java account's name
@@ -264,14 +262,6 @@ allowFloodgateNameConflict: false
 # Enabling this might lead to people gaining unauthorized access to other's accounts!
 autoRegisterFloodgate: false
 
-# Make FastLogin inject the Floodgate name prefixes, instead of Floodgate.
-# This can fix prefixes, if you are using Floodgate alongside ProtocolLib.
-# If either of those plugins are not installed, this option will have no effect.
-# For more information visit: https://github.com/games647/FastLogin/issues/493
-# !!!!!!!! WARNING: FLOODGATE SUPPORT IS AN EXPERIMENTAL FEATURE !!!!!!!!
-# Enabling this might lead to people gaining unauthorized access to other's accounts!
-floodgatePrefixWorkaround: false
-
 # This option resembles the vanilla configuration option 'enforce-secure-profile' in the 'server.properties' file.
 # It verifies if the incoming cryptographic key in the login request from the player is signed by Mojang. This key
 # is necessary for servers where you or other in-game players want to verify that a chat message sent and signed by