0026-Better-Decompression-Sanity.patch

From f56b491d0446e50c02dfc076242a1e9133f7bd88 Mon Sep 17 00:00:00 2001
From: Techcable <Techcable@techcable.net>
Date: Fri, 18 Mar 2016 10:53:24 -0700
Subject: [PATCH] Better Decompression Sanity

Fixes #40

diff --git a/proxy/src/main/java/net/md_5/bungee/compress/PacketDecompressor.java b/proxy/src/main/java/net/md_5/bungee/compress/PacketDecompressor.java
index 21b3ea2b..37fe6ac7 100644
--- a/proxy/src/main/java/net/md_5/bungee/compress/PacketDecompressor.java
+++ b/proxy/src/main/java/net/md_5/bungee/compress/PacketDecompressor.java
@@ -1,5 +1,7 @@
 package net.md_5.bungee.compress;
 
+import lombok.*;
+
 import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
@@ -8,9 +10,11 @@ import java.util.List;
 import net.md_5.bungee.jni.zlib.BungeeZlib;
 import net.md_5.bungee.protocol.DefinedPacket;
 
+@RequiredArgsConstructor
 public class PacketDecompressor extends MessageToMessageDecoder<ByteBuf>
 {
 
+    private final int compressionThreshold;
     private final BungeeZlib zlib = CompressFactory.zlib.newInstance();
 
     @Override
@@ -35,12 +39,13 @@ public class PacketDecompressor extends MessageToMessageDecoder<ByteBuf>
             in.skipBytes( in.readableBytes() );
         } else
         {
+            Preconditions.checkArgument( size >= compressionThreshold, "Decompressed size %s less than compression threshold %s", size, compressionThreshold);
             ByteBuf decompressed = ctx.alloc().directBuffer();
 
             try
             {
                 zlib.process( in, decompressed );
-                Preconditions.checkState( decompressed.readableBytes() == size, "Decompressed packet size mismatch" );
+                Preconditions.checkArgument( decompressed.readableBytes() == size, "Decompressed size %s is not equal to actual decompressed bytes", size, decompressed.readableBytes());
 
                 out.add( decompressed );
                 decompressed = null;
diff --git a/proxy/src/main/java/net/md_5/bungee/netty/ChannelWrapper.java b/proxy/src/main/java/net/md_5/bungee/netty/ChannelWrapper.java
index 28a4f176..0107ac03 100644
--- a/proxy/src/main/java/net/md_5/bungee/netty/ChannelWrapper.java
+++ b/proxy/src/main/java/net/md_5/bungee/netty/ChannelWrapper.java
@@ -136,7 +136,7 @@ public class ChannelWrapper
 
         if ( ch.pipeline().get( PacketDecompressor.class ) == null && compressionThreshold != -1 )
         {
-            addBefore( PipelineUtils.PACKET_DECODER, "decompress", new PacketDecompressor() );
+            addBefore( PipelineUtils.PACKET_DECODER, "decompress", new PacketDecompressor(compressionThreshold) );
         }
         if ( compressionThreshold == -1 )
         {
-- 
2.11.0