Paper/patches/server/0568-Limit-recipe-packets.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sat, 12 Dec 2020 23:45:28 +0000
Subject: [PATCH] Limit recipe packets


diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index 3e486376a49a61d52cdcd32ea877996d81186a73..e62bb33852b0dca346aeb3cb2747d1a5686dea2d 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -334,6 +334,13 @@ public class PaperConfig {
         tabSpamLimit = getInt("settings.spam-limiter.tab-spam-limit", tabSpamLimit);
     }
 
+    public static int autoRecipeIncrement = 1;
+    public static int autoRecipeLimit = 20;
+    private static void autoRecipieLimiters() {
+        autoRecipeIncrement = getInt("settings.spam-limiter.recipe-spam-increment", autoRecipeIncrement);
+        autoRecipeLimit = getInt("settings.spam-limiter.recipe-spam-limit", autoRecipeLimit);
+    }
+
     public static boolean velocitySupport;
     public static boolean velocityOnlineMode;
     public static byte[] velocitySecretKey;
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 5b42180e7e289f498763f2d64ae1e47130259899..dc4809a4e77db84b992b5bd0d2f6b103accf91a9 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -231,6 +231,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
     // CraftBukkit start - multithreaded fields
     private AtomicInteger chatSpamTickCount = new AtomicInteger();
     private final java.util.concurrent.atomic.AtomicInteger tabSpamLimiter = new java.util.concurrent.atomic.AtomicInteger(); // Paper - configurable tab spam limits
+    private final java.util.concurrent.atomic.AtomicInteger recipeSpamPackets =  new java.util.concurrent.atomic.AtomicInteger(); // Paper - auto recipe limit
     // CraftBukkit end
     private int dropSpamTickCount;
     private double firstGoodX;
@@ -376,6 +377,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         // CraftBukkit start
         for (int spam; (spam = this.chatSpamTickCount.get()) > 0 && !this.chatSpamTickCount.compareAndSet(spam, spam - 1); ) ;
         if (tabSpamLimiter.get() > 0) tabSpamLimiter.getAndDecrement(); // Paper - split to seperate variable
+        if (recipeSpamPackets.get() > 0) recipeSpamPackets.getAndDecrement(); // Paper
         /* Use thread-safe field access instead
         if (this.chatSpamTickCount > 0) {
             --this.chatSpamTickCount;
@@ -2790,6 +2792,14 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
 
     @Override
     public void handlePlaceRecipe(ServerboundPlaceRecipePacket packet) {
+        // Paper start
+        if (!org.bukkit.Bukkit.isPrimaryThread()) {
+            if (recipeSpamPackets.addAndGet(com.destroystokyo.paper.PaperConfig.autoRecipeIncrement) > com.destroystokyo.paper.PaperConfig.autoRecipeLimit) {
+                server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]))); // Paper
+                return;
+            }
+        }
+        // Paper end
         PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel());
         this.player.resetLastActionTime();
         if (!this.player.isSpectator() && this.player.containerMenu.containerId == packet.getContainerId() && this.player.containerMenu instanceof RecipeBookMenu) {