diff --git a/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java b/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java index 081253594..ec2f9ded7 100644 --- a/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java +++ b/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java @@ -2,8 +2,10 @@ package com.velocitypowered.proxy.protocol.netty; import com.velocitypowered.proxy.protocol.ProtocolUtils; import io.netty.buffer.ByteBuf; +import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.ByteToMessageDecoder; +import io.netty.handler.codec.CorruptedFrameException; import java.util.List; @@ -15,12 +17,26 @@ public class MinecraftVarintFrameDecoder extends ByteToMessageDecoder { } in.markReaderIndex(); - int packetLength = ProtocolUtils.readVarInt(in); - if (in.readableBytes() < packetLength) { - in.resetReaderIndex(); - return; + + byte[] lenBuf = new byte[3]; + for (int i = 0; i < lenBuf.length; i++) { + lenBuf[i] = in.readByte(); + if (lenBuf[i] > 0) { + int packetLength = ProtocolUtils.readVarInt(Unpooled.wrappedBuffer(lenBuf)); + if (packetLength == 0) { + return; + } + + if (in.readableBytes() < packetLength) { + in.resetReaderIndex(); + return; + } + + out.add(in.readRetainedSlice(packetLength)); + return; + } } - out.add(in.readRetainedSlice(packetLength)); + throw new CorruptedFrameException("VarInt too big"); } }