Expand AntiNocom

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

@@ -28,10 +28,45 @@ import de.steamwar.techhider.TechHider;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 
+import java.util.function.Function;
+
 public class AntiNocom {
 
     public AntiNocom() {
         TinyProtocol.instance.addFilter(blockDig, this::onDig);
+
+        if(Core.getVersion() > 8) {
+            registerUseItem();
+        }
+    }
+
+    private void registerUseItem() {
+        Class<?> useItem = Reflection.getClass("{nms.network.protocol.game}.PacketPlayInUseItem");
+
+        Function<Object, Object> getPosition;
+        if(Core.getVersion() > 12) {
+            Class<?> movingObjectPositionBlock = Reflection.getClass("{nms.world.phys}.MovingObjectPositionBlock");
+            Reflection.FieldAccessor<?> useItemPosition = Reflection.getField(useItem, movingObjectPositionBlock, 0);
+            Reflection.FieldAccessor<?> movingBlockPosition = Reflection.getField(movingObjectPositionBlock, TechHider.blockPosition, 0);
+
+            getPosition = (packet) -> movingBlockPosition.get(useItemPosition.get(packet));
+        } else {
+            getPosition = Reflection.getField(blockDig, TechHider.blockPosition, 0)::get;
+        }
+
+        TinyProtocol.instance.addFilter(useItem, (player, packet) -> {
+            Object pos = getPosition.apply(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 using item on unloaded block (potential NoCom-DOS attack)", x + " " + z);
+                return null;
+            }
+
+            return packet;
+        });
     }
 
     private static final Class<?> blockDig = Reflection.getClass("{nms.network.protocol.game}.PacketPlayInBlockDig");