message: Reject HANDSHAKE_DONE before handshake completion
diff: @@ -1667,7 +1667,7 @@ impl Connection {
  self.set_state(State::Closed(error_code.into()));
  }
  Frame::HandshakeDone => {
  - if self.role == Role::Server {
  + if self.role == Role::Server || !self.state.connected() {
  return Err(Error::ProtocolViolation);
  }
  self.set_state(State::Confirmed);
  