The continuation frame causes the connection to drop

[doufu3344]

oatpp-websocket/src/oatpp-websocket/WebSocket.cpp

Lines 202 to 219 in d95c8ee

	void WebSocket::handleFrame(const Frame::Header& frameHeader) {
	switch (frameHeader.opcode) {
	case Frame::OPCODE_CONTINUATION:
	if(m_lastOpcode < 0) {
	throw std::runtime_error("[oatpp::web::protocol::websocket::WebSocket::handleFrame()]: Invalid communication state.");
	}
	readPayload(frameHeader, nullptr);
	break;
	case Frame::OPCODE_TEXT:
	if(checkForContinuation(frameHeader)) {
	readPayload(frameHeader, nullptr);
	} else {
	throw std::runtime_error("[oatpp::web::protocol::websocket::WebSocket::handleFrame()]: Invalid communication state. OPCODE_CONTINUATION expected");
	}
	break;

In the above code, the m_lastOpcode member is not updated when processing a frame with opcode=Frame::OPCODE_CONTINUATION and fin=true , so when processing Frame::OPCODE_TEXT for the next frame, checkForContinuation() returns false and throws an exception. This results in a service disconnection.

oatpp-websocket/src/oatpp-websocket/WebSocket.cpp

Lines 58 to 68 in d95c8ee

	bool WebSocket::checkForContinuation(const Frame::Header& frameHeader) {
	if(m_lastOpcode == Frame::OPCODE_TEXT || m_lastOpcode == Frame::OPCODE_BINARY) {
	return false;
	}
	if(frameHeader.fin) {
	m_lastOpcode = -1;
	} else {
	m_lastOpcode = frameHeader.opcode;
	}
	return true;
	}

The same problem exists with asynchronous implementations