Merge pull request 'Anti NoCom DOS' (#229) from anti-nocom into master

Reviewed-on: #229
Reviewed-by: YoyoNow <jwsteam@nidido.de>

SpigotCore_Main/src/de/steamwar/core/Core.java

@@ -22,10 +22,7 @@ package de.steamwar.core;
 import com.comphenix.tinyprotocol.TinyProtocol;
 import de.steamwar.command.*;
 import de.steamwar.core.authlib.AuthlibInjector;
-import de.steamwar.core.events.ChattingEvent;
+import de.steamwar.core.events.*;
-import de.steamwar.core.events.PartialChunkFixer;
-import de.steamwar.core.events.PlayerJoinedEvent;
-import de.steamwar.core.events.WorldLoadEvent;
 import de.steamwar.message.Message;
 import de.steamwar.network.NetworkReceiver;
 import de.steamwar.network.handlers.ServerDataHandler;
@@ -99,6 +96,8 @@ public class Core extends JavaPlugin{
 			AuthlibInjector.inject();
 		TinyProtocol.init();
 
+		new AntiNocom();
+
 		if(Core.getVersion() < 17 && Bukkit.getPluginManager().getPlugin("ViaVersion") != null)
 			new PartialChunkFixer();
 

SpigotCore_Main/src/de/steamwar/core/events/AntiNocom.java

@@ -0,0 +1,50 @@
+/*
+ *    This file is a part of the SteamWar software.
+ *
+ *    Copyright (C) 2023  SteamWar.de-Serverteam
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Affero General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.core.events;
+
+import com.comphenix.tinyprotocol.Reflection;
+import com.comphenix.tinyprotocol.TinyProtocol;
+import de.steamwar.core.Core;
+import de.steamwar.sql.SWException;
+import de.steamwar.techhider.ProtocolUtils;
+import de.steamwar.techhider.TechHider;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+public class AntiNocom {
+
+    public AntiNocom() {
+        TinyProtocol.instance.addFilter(blockDig, this::onDig);
+    }
+
+    private static final Class<?> blockDig = Reflection.getClass("{nms.network.protocol.game}.PacketPlayInBlockDig");
+    private static final Reflection.FieldAccessor<?> digPosition = Reflection.getField(blockDig, TechHider.blockPosition, 0);
+    private Object onDig(Player player, Object packet) {
+        Object pos = digPosition.get(packet);
+        int x = TechHider.blockPositionX.get(pos);
+        int z = TechHider.blockPositionZ.get(pos);
+        if(!player.getWorld().isChunkLoaded(ProtocolUtils.posToChunk(x), ProtocolUtils.posToChunk(z))) {
+            Bukkit.getScheduler().runTask(Core.getInstance(), () -> player.kickPlayer(null));
+            SWException.log(player.getName() + " kicked for digging an unloaded block (potential NoCom-DOS attack)", "");
+            return null;
+        }
+        return packet;
+    }
+}