From 204b7b7e3cf0ed14e88407f662f7418c6fb4a1cf Mon Sep 17 00:00:00 2001
From: Zach Brown <zach.brown@destroystokyo.com>
Date: Sat, 10 Sep 2016 21:40:51 -0500
Subject: [PATCH] Rate limit PacketPlayInUseItem


diff --git a/src/main/java/net/minecraft/server/PacketPlayInUseItem.java b/src/main/java/net/minecraft/server/PacketPlayInUseItem.java
index 82e09c1..88ac278 100644
--- a/src/main/java/net/minecraft/server/PacketPlayInUseItem.java
+++ b/src/main/java/net/minecraft/server/PacketPlayInUseItem.java
@@ -10,6 +10,7 @@ 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() {}
 
@@ -20,6 +21,7 @@ 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 {
@@ -29,6 +31,7 @@ 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 3d04119..2f6d58c 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -865,6 +865,10 @@ 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;
+    // Paper end
     public void a(PacketPlayInUseItem packetplayinuseitem) {
         PlayerConnectionUtils.ensureMainThread(packetplayinuseitem, this, this.player.x());
         if (this.player.cj()) return; // CraftBukkit
@@ -875,12 +879,22 @@ 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
+        boolean throttled = false;
+        if (lastPlaceUse != -1 && packetplayinuseitem.timestamp - lastPlaceUse < 30 && packetsUse++ >= 4) {
+            throttled = true;
+        } else if (packetplayinuseitem.timestamp - lastPlaceUse >= 30 || 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())});
 
             chatmessage.getChatModifier().setColor(EnumChatFormat.RED);
             this.player.playerConnection.sendPacket(new PacketPlayOutChat(chatmessage));
-        } else if (this.teleportPos == null && this.player.e((double) blockposition.getX() + 0.5D, (double) blockposition.getY() + 0.5D, (double) blockposition.getZ() + 0.5D) < 64.0D && !this.minecraftServer.a(worldserver, blockposition, this.player) && worldserver.getWorldBorder().a(blockposition)) {
+        // Paper - Ignore if throttled
+        } else if (!throttled && this.teleportPos == null && this.player.e((double) blockposition.getX() + 0.5D, (double) blockposition.getY() + 0.5D, (double) blockposition.getZ() + 0.5D) < 64.0D && !this.minecraftServer.a(worldserver, blockposition, this.player) && worldserver.getWorldBorder().a(blockposition)) {
             // CraftBukkit start - Check if we can actually do something over this large a distance
             Location eyeLoc = this.getPlayer().getEyeLocation();
             double reachDistance = NumberConversions.square(eyeLoc.getX() - blockposition.getX()) + NumberConversions.square(eyeLoc.getY() - blockposition.getY()) + NumberConversions.square(eyeLoc.getZ() - blockposition.getZ());
-- 
2.10.0.windows.1