Jak wykryć koniec strumienia w BinaryReader?

TcpClient client = server.AcceptTcpClient();
NetworkStream stream = client.GetStream();
BinaryReader reader = new BinaryReader(stream);
FileStream FileWriter = new FileStream("sciezka", FileMode.Append);
int receivedBytesLength;

while ([jaki warunek tutaj wstawić????])
{
receivedBytesLength = reader.Read(buffer, 0, buffer.Length);
FileWriter.Write(buffer, 0, receivedBytesLength);
FileWriter.Flush();
}