Add rate limiter for incoming packets

Signed-off-by: TheMode <themode@outlook.fr>

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

@@ -60,10 +60,6 @@ public final class MinecraftServer {
     public static final int TICK_PER_SECOND = Integer.getInteger("minestom.tps", 20);
     public static final int TICK_MS = 1000 / TICK_PER_SECOND;
 
-    // Network monitoring
-    private static int rateLimit = 300;
-    private static int maxPacketSize = 30_000;
-
     // In-Game Manager
     private static volatile ServerProcess serverProcess;
 
@@ -112,42 +108,6 @@ public final class MinecraftServer {
         PacketUtils.broadcastPacket(PluginMessagePacket.getBrandPacket());
     }
 
-    /**
-     * Gets the maximum number of packets a client can send over 1 second.
-     *
-     * @return the packet count limit over 1 second, 0 if not enabled
-     */
-    public static int getRateLimit() {
-        return rateLimit;
-    }
-
-    /**
-     * Changes the number of packet a client can send over 1 second without being disconnected.
-     *
-     * @param rateLimit the number of packet, 0 to disable
-     */
-    public static void setRateLimit(int rateLimit) {
-        MinecraftServer.rateLimit = rateLimit;
-    }
-
-    /**
-     * Gets the maximum packet size (in bytes) that a client can send without getting disconnected.
-     *
-     * @return the maximum packet size
-     */
-    public static int getMaxPacketSize() {
-        return maxPacketSize;
-    }
-
-    /**
-     * Changes the maximum packet size (in bytes) that a client can send without getting disconnected.
-     *
-     * @param maxPacketSize the new max packet size
-     */
-    public static void setMaxPacketSize(int maxPacketSize) {
-        MinecraftServer.maxPacketSize = maxPacketSize;
-    }
-
     /**
      * Gets the server difficulty showed in game option.
      *

src/main/java/net/minestom/server/entity/Player.java

@@ -44,6 +44,7 @@ import net.minestom.server.inventory.PlayerInventory;
 import net.minestom.server.item.ItemStack;
 import net.minestom.server.item.Material;
 import net.minestom.server.item.metadata.WrittenBookMeta;
+import net.minestom.server.listener.manager.PacketListenerManager;
 import net.minestom.server.message.ChatMessageType;
 import net.minestom.server.message.ChatPosition;
 import net.minestom.server.message.Messenger;
@@ -106,6 +107,8 @@ import java.util.function.UnaryOperator;
 public class Player extends LivingEntity implements CommandSender, Localizable, HoverEventSource<ShowEntity>, Identified, NamedAndIdentified {
 
     private static final Component REMOVE_MESSAGE = Component.text("You have been removed from the server without reason.", NamedTextColor.RED);
+    private static final int PACKET_PER_TICK = Integer.getInteger("minestom.packet-per-tick", 20);
+    private static final int PACKET_QUEUE_SIZE = Integer.getInteger("minestom.packet-queue-size", 1000);
 
     private long lastKeepAlive;
     private boolean answerKeepAlive;
@@ -319,9 +322,6 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
 
     @Override
     public void update(long time) {
-        // Network tick
-        this.playerConnection.update();
-
         // Process received packets
         interpretPacketQueue();
 
@@ -1731,8 +1731,13 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
     @ApiStatus.Internal
     @ApiStatus.Experimental
     public void interpretPacketQueue() {
+        if (this.packets.size() >= PACKET_QUEUE_SIZE) {
+            kick(Component.text("Too Many Packets", NamedTextColor.RED));
+            return;
+        }
+        final PacketListenerManager manager = MinecraftServer.getPacketListenerManager();
         // This method is NOT thread-safe
-        this.packets.drain(packet -> MinecraftServer.getPacketListenerManager().processClientPacket(packet, this));
+        this.packets.drain(packet -> manager.processClientPacket(packet, this), PACKET_PER_TICK);
     }
 
     /**

src/main/java/net/minestom/server/network/PacketProcessor.java

@@ -1,6 +1,5 @@
 package net.minestom.server.network;
 
-import net.minestom.server.MinecraftServer;
 import net.minestom.server.entity.Player;
 import net.minestom.server.network.packet.client.ClientPacket;
 import net.minestom.server.network.packet.client.ClientPacketsHandler;
@@ -41,11 +40,7 @@ public record PacketProcessor(@NotNull ClientPacketsHandler statusHandler,
     }
 
     public void process(@NotNull PlayerConnection connection, int packetId, ByteBuffer body) {
-        if (MinecraftServer.getRateLimit() > 0) {
+        final ClientPacket packet = create(connection.getConnectionState(), packetId, body);
-            // Increment packet count (checked in PlayerConnection#update)
-            connection.getPacketCounter().incrementAndGet();
-        }
-        var packet = create(connection.getConnectionState(), packetId, body);
         if (packet instanceof ClientPreplayPacket prePlayPacket) {
             prePlayPacket.process(connection);
         } else {

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

@@ -1,11 +1,8 @@
 package net.minestom.server.network.player;
 
-import net.kyori.adventure.text.Component;
-import net.kyori.adventure.text.format.NamedTextColor;
 import net.minestom.server.MinecraftServer;
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Player;
-import net.minestom.server.listener.manager.PacketListenerManager;
 import net.minestom.server.network.ConnectionState;
 import net.minestom.server.network.packet.server.SendablePacket;
 import org.jetbrains.annotations.ApiStatus;
@@ -15,57 +12,21 @@ import org.jetbrains.annotations.Nullable;
 import java.net.SocketAddress;
 import java.util.Collection;
 import java.util.List;
-import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * A PlayerConnection is an object needed for all created {@link Player}.
  * It can be extended to create a new kind of player (NPC for instance).
  */
 public abstract class PlayerConnection {
-    protected static final PacketListenerManager PACKET_LISTENER_MANAGER = MinecraftServer.getPacketListenerManager();
-
     private Player player;
     private volatile ConnectionState connectionState;
     volatile boolean online;
 
-    // Text used to kick client sending too many packets
-    private static final Component rateLimitKickMessage = Component.text("Too Many Packets", NamedTextColor.RED);
-
-    //Connection Stats
-    private final AtomicInteger packetCounter = new AtomicInteger(0);
-    private final AtomicInteger lastPacketCounter = new AtomicInteger(0);
-    private short tickCounter = 0;
-
     public PlayerConnection() {
         this.online = true;
         this.connectionState = ConnectionState.UNKNOWN;
     }
 
-    /**
-     * Updates values related to the network connection.
-     */
-    public void update() {
-        // Check rate limit
-        if (MinecraftServer.getRateLimit() > 0) {
-            tickCounter++;
-            if (tickCounter % MinecraftServer.TICK_PER_SECOND == 0 && tickCounter > 0) {
-                tickCounter = 0;
-                // Retrieve the packet count
-                final int count = packetCounter.getAndSet(0);
-                this.lastPacketCounter.set(count);
-                if (count > MinecraftServer.getRateLimit()) {
-                    // Sent too many packets
-                    player.kick(rateLimitKickMessage);
-                    disconnect();
-                }
-            }
-        }
-    }
-
-    public @NotNull AtomicInteger getPacketCounter() {
-        return packetCounter;
-    }
-
     /**
      * Returns a printable identifier for this connection, will be the player username
      * or the connection remote address.
@@ -189,15 +150,6 @@ public abstract class PlayerConnection {
         return connectionState;
     }
 
-    /**
-     * Gets the number of packet the client sent over the last second.
-     *
-     * @return the number of packet sent over the last second
-     */
-    public int getLastPacketCounter() {
-        return lastPacketCounter.get();
-    }
-
     @Override
     public String toString() {
         return "PlayerConnection{" +