From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Zach Brown <1254957+zachbr@users.noreply.github.com>
Date: Sat, 10 Sep 2016 21:40:51 -0500
Subject: [PATCH] Rate limit PacketPlayInUseItem


diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -0,0 +0,0 @@ public class PaperConfig {
     private static void bungeeOnlineMode() {
         bungeeOnlineMode = getBoolean("settings.bungee-online-mode", true);
     }
+    
+    public static int playInUseItemThreshold = 300;
+    private static void playInUseItemThreshold() {
+        playInUseItemThreshold = getInt("settings.play-in-use-item-spam-threshold", 300);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/PacketPlayInUseItem.java b/src/main/java/net/minecraft/server/PacketPlayInUseItem.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/PacketPlayInUseItem.java
+++ b/src/main/java/net/minecraft/server/PacketPlayInUseItem.java
@@ -0,0 +0,0 @@ public class PacketPlayInUseItem implements Packet<PacketListenerPlayIn> {
     private float d;
     private float e;
     private float f;
+    public long timestamp; // Paper - Used for rate limiting
 
     public PacketPlayInUseItem() {}
 
@@ -0,0 +0,0 @@ public class PacketPlayInUseItem implements Packet<PacketListenerPlayIn> {
         this.d = (float) packetdataserializer.readUnsignedByte() / 16.0F;
         this.e = (float) packetdataserializer.readUnsignedByte() / 16.0F;
         this.f = (float) packetdataserializer.readUnsignedByte() / 16.0F;
+        this.timestamp = System.currentTimeMillis(); // Paper
     }
 
     public void b(PacketDataSerializer packetdataserializer) throws IOException {
@@ -0,0 +0,0 @@ public class PacketPlayInUseItem implements Packet<PacketListenerPlayIn> {
         packetdataserializer.writeByte((int) (this.d * 16.0F));
         packetdataserializer.writeByte((int) (this.e * 16.0F));
         packetdataserializer.writeByte((int) (this.f * 16.0F));
+        this.timestamp = System.currentTimeMillis(); // Paper
     }
 
     public void a(PacketListenerPlayIn packetlistenerplayin) {
diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -0,0 +0,0 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
         // CraftBukkit end
     }
 
+    // Paper start - Rate limit UseItem as well, copied from Spigot implementation below in BlockPlace
+    private long lastPlaceUse = -1;
+    private int packetsUse = 0;
+    private static final int THRESHOLD = com.destroystokyo.paper.PaperConfig.playInUseItemThreshold;
+    // Paper end
     public void a(PacketPlayInUseItem packetplayinuseitem) {
         PlayerConnectionUtils.ensureMainThread(packetplayinuseitem, this, this.player.x());
         if (this.player.cj()) return; // CraftBukkit
@@ -0,0 +0,0 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
         EnumDirection enumdirection = packetplayinuseitem.b();
 
         this.player.resetIdleTimer();
+
+        // Paper start - Rate limit UseItem as well, copied from Spigot implementation below in BlockPlace
+        if (lastPlaceUse != -1 && packetplayinuseitem.timestamp - lastPlaceUse < THRESHOLD && packetsUse++ >= 4) {
+            return;
+        } else if (packetplayinuseitem.timestamp - lastPlaceUse >= THRESHOLD || lastPlaceUse == -1) {
+            lastPlaceUse = packetplayinuseitem.timestamp;
+            packetsUse = 0;
+        }
+        // Paper end
+
         if (blockposition.getY() >= this.minecraftServer.getMaxBuildHeight() - 1 && (enumdirection == EnumDirection.UP || blockposition.getY() >= this.minecraftServer.getMaxBuildHeight())) {
             ChatMessage chatmessage = new ChatMessage("build.tooHigh", new Object[] { Integer.valueOf(this.minecraftServer.getMaxBuildHeight())});
 
--