Set WebSocket max message size to 256KB

Author: paullouisageneau

src/channel.cpp

@@ -17,7 +17,7 @@ Channel::~Channel() { impl()->resetCallbacks(); }
 
 Channel::Channel(impl_ptr<impl::Channel> impl) : CheshireCat<impl::Channel>(std::move(impl)) {}
 
-size_t Channel::maxMessageSize() const { return DEFAULT_MAX_MESSAGE_SIZE; }
+size_t Channel::maxMessageSize() const { return 0; }
 
 size_t Channel::bufferedAmount() const { return impl()->bufferedAmount; }
 

src/impl/datachannel.cpp

@@ -153,7 +153,7 @@ bool DataChannel::isClosed(void) const { return mIsClosed; }
 
 size_t DataChannel::maxMessageSize() const {
 	auto pc = mPeerConnection.lock();
-	return pc ? pc->remoteMaxMessageSize() : DEFAULT_MAX_MESSAGE_SIZE;
+	return pc ? pc->remoteMaxMessageSize() : DEFAULT_REMOTE_MAX_MESSAGE_SIZE;
 }
 
 void DataChannel::assignStream(uint16_t stream) {

src/impl/internals.hpp

@@ -39,7 +39,9 @@ const uint16_t MAX_SCTP_STREAMS_COUNT = 1024; // Max number of negotiated SCTP s
                                               // of memory, Chromium historically limits to 1024.
 
 const size_t DEFAULT_LOCAL_MAX_MESSAGE_SIZE = 256 * 1024; // Default local max message size
-const size_t DEFAULT_MAX_MESSAGE_SIZE = 65536; // Remote max message size if not specified in SDP
+const size_t DEFAULT_REMOTE_MAX_MESSAGE_SIZE = 65536;     // Remote max message size if not in SDP
+
+const size_t DEFAULT_WS_MAX_MESSAGE_SIZE = 256 * 1024;   // Default max message size for WebSockets
 
 const size_t RECV_QUEUE_LIMIT = 1024 * 1024; // Max per-channel queue size
 

src/impl/peerconnection.cpp

@@ -103,7 +103,7 @@ optional<Description> PeerConnection::remoteDescription() const {
 size_t PeerConnection::remoteMaxMessageSize() const {
 	const size_t localMax = config.maxMessageSize.value_or(DEFAULT_LOCAL_MAX_MESSAGE_SIZE);
 
-	size_t remoteMax = DEFAULT_MAX_MESSAGE_SIZE;
+	size_t remoteMax = DEFAULT_REMOTE_MAX_MESSAGE_SIZE;
 	std::lock_guard lock(mRemoteDescriptionMutex);
 	if (mRemoteDescription)
 		if (auto *application = mRemoteDescription->application())

src/impl/websocket.cpp

@@ -156,7 +156,7 @@ bool WebSocket::isOpen() const { return state == State::Open; }
 
 bool WebSocket::isClosed() const { return state == State::Closed; }
 
-size_t WebSocket::maxMessageSize() const { return config.maxMessageSize.value_or(DEFAULT_MAX_MESSAGE_SIZE); }
+size_t WebSocket::maxMessageSize() const { return config.maxMessageSize.value_or(DEFAULT_WS_MAX_MESSAGE_SIZE); }
 
 optional<message_variant> WebSocket::receive() {
 	auto next = mRecvQueue.pop();

src/impl/wstransport.cpp

@@ -53,7 +53,7 @@ WsTransport::WsTransport(LowerTransport lower, shared_ptr<WsHandshake> handshake
           std::visit(rtc::overloaded{[](auto l) { return l->isActive(); },
                                      [](shared_ptr<TlsTransport> l) { return l->isClient(); }},
                      lower)),
-      mMaxMessageSize(config.maxMessageSize.value_or(DEFAULT_MAX_MESSAGE_SIZE)),
+      mMaxMessageSize(config.maxMessageSize.value_or(DEFAULT_WS_MAX_MESSAGE_SIZE)),
       mMaxOutstandingPings(config.maxOutstandingPings.value_or(0)) {
 
 	onRecv(std::move(recvCallback));