Paper/patches/server/0538-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 c0c807522aaa82ca74c47849b47e6b6b48b9a6f8..1de3d8848419fce792e28c8100eca1b2488ac968 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -365,6 +365,13 @@ 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 c0a685cfe62aeda3583763ecc1e4fa127f8fb0d4..ff36ca2dbdf4a9abb953097f1b6246a177370b02 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -230,6 +230,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
     // CraftBukkit start - multithreaded fields
     private final 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;
@@ -375,6 +376,7 @@ 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;
@@ -2810,6 +2812,14 @@ 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) {