public OperationStatus HandlePacket(ref ReceiveState state)
{
var connection = state.Connection;
Debug.Assert(connection != null);
OperationStatus status;
var clientReader = state.Reader;
long initialClientPosition = clientReader.Position;
long initialClientLength = clientReader.Length;
if (clientReader.PeekByte() == LegacyServerListPingPacketDefinition.RawId)
{
clientReader.Position++;
if ((status = ReadLegacyServerListPing(connection, clientReader)) != OperationStatus.NeedMoreData)
{
connection.Close(immediate: false);
}
goto ResetReaderAndReturn;
}
if ((status = clientReader.Read(out VarInt packetLength, out int packetLengthBytes)) != OperationStatus.Done)
{
goto ResetReaderAndReturn;
}
if (packetLength > NetManager.MaxClientPacketSize)
{
connection.Kick($"Packet length {packetLength} exceeds {NetManager.MaxClientPacketSize}.");
return(OperationStatus.InvalidData);
}
if (clientReader.Remaining < packetLength)
{
status = OperationStatus.NeedMoreData;
goto ResetReaderAndReturn;
}
VarInt dataLength;
Stream packetStream;
// CompressionThreshold < 0 == disabled
// CompressionThreshold = 0 == enabled for all
// CompressionThreshold > x == enabled for sizes >= x
if (connection.CompressionThreshold >= 0)
{
if ((status = clientReader.Read(out dataLength, out int dataLengthBytes)) != OperationStatus.Done)
{
return(status);
}
if (dataLength != 0)
{
if ((status = ValidateDataLength(connection, dataLength)) != OperationStatus.Done)
{
return(status);
}
var decompressionBuffer = connection.DecompressionBuffer;
using (var decompressor = new ZlibStream(clientReader.BaseStream, CompressionMode.Decompress, true))
{
decompressionBuffer.SetLength(0);
decompressionBuffer.Position = 0;
if (decompressor.SpanWriteTo(decompressionBuffer, dataLength) != dataLength)
{
return(OperationStatus.InvalidData);
}
}
decompressionBuffer.Position = 0;
packetStream = decompressionBuffer;
}
else
{
dataLength = packetLength - packetLengthBytes - dataLengthBytes;
if ((status = ValidateDataLength(connection, dataLength)) != OperationStatus.Done)
{
return(status);
}
packetStream = clientReader.BaseStream;
}
}
else
{
dataLength = packetLength - packetLengthBytes;
status = ValidateDataLength(connection, dataLength);
if (status != OperationStatus.Done)
{
return(status);
}
packetStream = clientReader.BaseStream;
}
var packetReader = new NetBinaryReader(packetStream);
if ((status = packetReader.Read(out VarInt rawPacketId, out int packetIdBytes)) != OperationStatus.Done)
{
connection.Kick("Packet ID is incorrectly encoded.");
return(status);
}
if (!Decoder.TryGetPacketIdDefinition(
state.ProtocolOverride ?? connection.ProtocolState,
rawPacketId,
out var packetIdDefinition))
{
connection.Kick($"Unknown packet ID \"{rawPacketId}\".");
return(OperationStatus.InvalidData);
}
// Ensure that the packet handler only gets as much data as the packet contains.
if (packetStream == clientReader.BaseStream)
{
packetStream.SetLength(packetStream.Position + dataLength);
}
var packetHandler = GetPacketHandler(packetIdDefinition.Id);
status = packetHandler.Invoke(connection, packetReader, packetIdDefinition, out int readLength);
if (status != OperationStatus.Done)
{
connection.Kick(
$"Internal server error caused by packet handler of {packetIdDefinition.Id} with status " + status);
return(status);
}
Debug.Assert(readLength <= dataLength, "Packet handler read too many bytes.");
clientReader.Length = initialClientLength; // Reset length after read.
// Skip data that was not read by the packet handler
long totalRead = clientReader.Position - initialClientPosition;
long toSkip = packetLength + packetLengthBytes - totalRead;
clientReader.Seek(toSkip, SeekOrigin.Current);
return(OperationStatus.Done);
ResetReaderAndReturn:
clientReader.Position = initialClientPosition;
return(status);
}