Fix ping exploit

Author: creeper123123321

src/main/java/org/dimdev/vanillafix/bugs/IPatchedSPacketPong.java

@@ -0,0 +1,5 @@
+package org.dimdev.vanillafix.bugs;
+
+public interface IPatchedSPacketPong {
+    long getClientTime();
+}

src/main/java/org/dimdev/vanillafix/bugs/mixins/MixinSPacketPong.java

@@ -0,0 +1,15 @@
+package org.dimdev.vanillafix.bugs.mixins;
+
+import net.minecraft.network.status.server.SPacketPong;
+import org.dimdev.vanillafix.bugs.IPatchedSPacketPong;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(SPacketPong.class)
+public class MixinSPacketPong implements IPatchedSPacketPong {
+    @Shadow private long clientTime;
+    @Override
+    public long getClientTime() {
+        return clientTime;
+    }
+}

src/main/java/org/dimdev/vanillafix/bugs/mixins/client/MixinServerPinger$1.java

@@ -0,0 +1,21 @@
+package org.dimdev.vanillafix.bugs.mixins.client;
+
+import net.minecraft.network.status.INetHandlerStatusClient;
+import net.minecraft.network.status.server.SPacketPong;
+import org.dimdev.vanillafix.bugs.IPatchedSPacketPong;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(targets = "net.minecraft.client.network.ServerPinger$1")
+public abstract class MixinServerPinger$1 implements INetHandlerStatusClient {
+    @Shadow private long pingSentAt;
+    @Inject(method = "handlePong", at = @At("HEAD"), cancellable = true)
+    public void handleHandlePong(SPacketPong packetIn, CallbackInfo ci) {
+        if (((IPatchedSPacketPong) packetIn).getClientTime() != pingSentAt) {
+            ci.cancel();
+        }
+    }
+}

src/main/resources/mixins.vanillafix.bugs.json

@@ -13,14 +13,16 @@
     "MixinInventoryPlayer",
     "MixinChunk",
     "MixinMinecraftServer",
-    "MixinStateImplementation"
+    "MixinStateImplementation",
+    "MixinSPacketPong"
   ],
   "client": [
     "client.MixinMinecraft",
     "client.MixinNetHandlerPlayClient",
     "client.MixinEntityPlayerSP",
     "client.MixinIntegratedServer",
-    "client.MixinEntityRenderer"
+    "client.MixinEntityRenderer",
+    "client.MixinServerPinger$1"
   ],
   "injectors": {
     "maxShiftBy": 10