expose remoteMaxMessageSize on c-apis

include/rtc/rtc.h

@@ -214,6 +214,8 @@ RTC_C_EXPORT int rtcGetSelectedCandidatePair(int pc, char *local, int localSize,
 
 RTC_C_EXPORT int rtcGetMaxDataChannelStream(int pc);
 
+RTC_C_EXPORT int rtcGetRemoteMaxMessageSize(int pc);
+
 // DataChannel, Track, and WebSocket common API
 
 RTC_C_EXPORT int rtcSetOpenCallback(int id, rtcOpenCallbackFunc cb);

src/capi.cpp

@@ -697,6 +697,13 @@ int rtcGetMaxDataChannelStream(int pc) {
 	});
 }
 
+int rtcGetRemoteMaxMessageSize(int pc) {
+	return wrap([&] {
+		auto peerConnection = getPeerConnection(pc);
+		return int(peerConnection->remoteMaxMessageSize());
+	});
+}
+
 int rtcSetOpenCallback(int id, rtcOpenCallbackFunc cb) {
 	return wrap([&] {
 		auto channel = getChannel(id);