WebRTCModule.peerConnectionInit returns false when using TURN server with iceServers key "urls"

[xaleel]

I spent many days trying to debug this issue, now I feel silly it's this simple, but I don't believe this is the expected behavior.

Expected Behavior:

peerConnection initializes

Observed Behavior:

App crashes with error message Failed to initialize PeerConnection, check the native logs!.

Steps to reproduce the issue:

const peerConstraints = {
	iceServers: [
		{
			url: "stun:stun.l.google.com:19302",
			// urls: "stun:stun.l.google.com:19302",
			// both work fine
		},
		{
			urls: "TURN:freeturn.net:3478", // this fails
			// urls: ["TURN:freeturn.net:3478"], // this also fails
			// url: "TURN:freeturn.net:3478", // (without the 's') this works
			// url: ["TURN:freeturn.net:3478"], // this also works
			username: "free",
			credential: "free",
		},
	],
	iceTransportPolicy: "all",
	rtcpMuxPolicy: "negotiate"
};
export default function CameraComponent(props: any) {
	const [peerConnection, setPeerConnection] = useState(new RTCPeerConnection(peerConstraints));
	...
}

According to w3 docs (MDN) the RTCIceServer Dictionary's key should be "urls". Using "url" should still be supported, in my opinion.

Platform Information

• React Native Version: 0.72.6
• WebRTC Module Version: ^111.0.6
• Platform OS + Version: Android 9, API 28, Samsung SM-G950F, expo ~49.0.18

[xaleel]

Additional info:
With the configuration that fails, I added debug lines to node_modules\react-native-webrtc\src\RTCPeerConnection.ts

export default class RTCPeerConnection extends EventTarget<RTCPeerConnectionEventMap> {
   ...
    constructor(configuration) {
        super();

        this._pcId = nextPeerConnectionId++;

        console.log("this._pcId", this._pcId);
        let peerCon = WebRTCModule.peerConnectionInit(configuration, this._pcId);
        console.log("peerCon", peerCon);

        if (!peerCon) {
            throw new Error('Failed to initialize PeerConnection, check the native logs!');
        }
       ...
    }
...
}

Console output:

[saghul]

Thanks for the report!

[saghul]

What error do you see in logcat?

This is the code for parsing ICE servers (WebRTCModule.java):

    private List<PeerConnection.IceServer> createIceServers(ReadableArray iceServersArray) {
        final int size = (iceServersArray == null) ? 0 : iceServersArray.size();
        List<PeerConnection.IceServer> iceServers = new ArrayList<>(size);
        for (int i = 0; i < size; i++) {
            ReadableMap iceServerMap = iceServersArray.getMap(i);
            boolean hasUsernameAndCredential = iceServerMap.hasKey("username") && iceServerMap.hasKey("credential");
            if (iceServerMap.hasKey("urls")) {
                switch (iceServerMap.getType("urls")) {
                    case String:
                        if (hasUsernameAndCredential) {
                            iceServers.add(createIceServer(iceServerMap.getString("urls"),
                                    iceServerMap.getString("username"),
                                    iceServerMap.getString("credential")));
                        } else {
                            iceServers.add(createIceServer(iceServerMap.getString("urls")));
                        }
                        break;
                    case Array:
                        ReadableArray urls = iceServerMap.getArray("urls");
                        for (int j = 0; j < urls.size(); j++) {
                            String url = urls.getString(j);
                            if (hasUsernameAndCredential) {
                                iceServers.add(createIceServer(
                                        url, iceServerMap.getString("username"), iceServerMap.getString("credential")));
                            } else {
                                iceServers.add(createIceServer(url));
                            }
                        }
                        break;
                }
            }
        }
        return iceServers;
    }

We don't check for url, just urls. So my guess is that the url entries are getting ignored. I wonder if the protocol might be checked in a case sensitive manner? Can you try urls: "turn:freeturn.net:3478", as a TURN server?

[xaleel]

There was nothing useful in Logcat. You're right, it was an issue with the case.
urls: "turn:freeturn.net:3478" doesn't cause the exception. I didn't even consider it.
Thank you!

[saghul]

Im reopening so we can fix this.

[8BallBomBom]

Looks like it is also an iOS issue, parsing code here.
But also someone complaining of the same error over here using iOS.

Then again as it is deprecated i'm not surprised 🤔
What does surprise me is how a simple thing causes such an issue.
Definitely something we can fix though 😸

[saghul]

Fix here: #1477

I chose to sanitize them on the JS side since that way we don't need to fix it twice on the native side.