From 3a8ba76f25ab1d6a1cf588e66944d283f5ba17a6 Mon Sep 17 00:00:00 2001 From: Andrew Steinborn Date: Sun, 31 May 2020 07:55:19 -0400 Subject: [PATCH] This did not work :( --- .../netty/MinecraftVarintFrameDecoder.java | 70 ++++++------------- 1 file changed, 21 insertions(+), 49 deletions(-) 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 1fdf8ece9..a4da29a76 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 @@ -1,16 +1,15 @@ package com.velocitypowered.proxy.protocol.netty; +import com.velocitypowered.proxy.protocol.ProtocolUtils; import com.velocitypowered.proxy.util.except.QuietException; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.ByteToMessageDecoder; -import io.netty.util.ByteProcessor; import java.util.List; public class MinecraftVarintFrameDecoder extends ByteToMessageDecoder { private static final QuietException BAD_LENGTH_CACHED = new QuietException("Bad packet length"); - private final VarintByteDecoder reader = new VarintByteDecoder(); @Override protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) { @@ -19,58 +18,31 @@ public class MinecraftVarintFrameDecoder extends ByteToMessageDecoder { return; } - while (in.isReadable()) { - int varintEnd = in.forEachByte(reader); - if (varintEnd == -1) { - return; - } - - if (reader.successfulDecode) { - if (reader.readVarint < 0) { - throw BAD_LENGTH_CACHED; - } - - int minimumRead = reader.bytesRead + reader.readVarint; - if (in.isReadable(minimumRead)) { - out.add(in.retainedSlice(varintEnd + 1, reader.readVarint)); - in.skipBytes(minimumRead); - reader.reset(); - } else { - reader.reset(); + read_lens: while (in.isReadable()) { + int origReaderIndex = in.readerIndex(); + for (int i = 0; i < 3; i++) { + if (!in.isReadable()) { + in.readerIndex(origReaderIndex); return; } - } else { - boolean tooBig = reader.bytesRead > 3; - reader.reset(); - if (tooBig) { - throw BAD_LENGTH_CACHED; + + byte read = in.readByte(); + if (read >= 0) { + // Make sure reader index of length buffer is returned to the beginning + in.readerIndex(origReaderIndex); + int packetLength = ProtocolUtils.readVarInt(in); + + if (in.readableBytes() >= packetLength) { + out.add(in.readBytes(packetLength)); + continue read_lens; + } else { + in.readerIndex(origReaderIndex); + return; + } } } - } - } - private static class VarintByteDecoder implements ByteProcessor { - private int readVarint; - private int bytesRead; - private boolean successfulDecode; - - @Override - public boolean process(byte k) { - readVarint |= (k & 0x7F) << bytesRead++ * 7; - if (bytesRead > 3) { - return false; - } - if ((k & 0x80) != 128) { - successfulDecode = true; - return false; - } - return true; - } - - void reset() { - readVarint = 0; - bytesRead = 0; - successfulDecode = false; + throw BAD_LENGTH_CACHED; } } }