bitbreeds-webrtc

Goal

The goal for bitbreeds-webrtc is to eventually make a simple Java peer for talking directly to one or several browsers or other WebRTC peers through an unordered/unreliable or unordered/reliable DataChannel.

At the moment the goal is to only allow it to be used as the "server" (the browser must initiate the WebRTC connection), though extending it to be able to act as a "client" (active side) should not be that hard, but it is not something I am interested in writing, since I do not need it at this moment.

Maturity

bitbreeds webrtc is experimental and not even close to complete and not ready for any kind of serious use.

How to run

Run locally.

Main class com.bitbreeds.webrtc.example.DatachannelServer will start a server on port 8443 accepting websocket connections.

Then run ./web/index.html in firefox to connect to the server, share candicates and start using WebRTC. If it works it should say ONMESSAGE

Run an example echo server

First, build webrtc-example like so:

mvn clean package -Pbuild-example

Then you can start the webrtc-example--.jar from the project root like this: This will use the default keystore in src/resources. ONLY FOR TESTING!.

java -jar webrtc-example/target/webrtc-example-0.2.6-SNAPSHOT-jar-with-dependencies.jar```

To supply the keystore do:

java -Dcom.bitbreeds.keystore=path-to-your-keystore -Dcom.bitbreeds.keystore.alias=your-key-alias -Dcom.bitbreeds.keystore.pass=your-key-pass -jar webrtc-example-1.0-SNAPSHOT-jar-with-dependencies.jar

If the server has problems finding its own public IP address, you can supply the IP address like this.

-Dcom.bitbreeds.ip=192.168.1.5

This might be needed since you must send a candidate to the other peer.

The keystore parameters are pretty self explanatory:

-Dcom.bitbreeds.keystore=./ws2.jks
-Dcom.bitbreeds.keystore.alias=websocket
-Dcom.bitbreeds.keystore.pass=websocket

Setting up a simple webrtc datachannel echoing input

Remember to provide your own keystore, the keystores provided are only for testing

SimplePeerServer peerConnectionServer = new SimplePeerServer(new KeystoreInfo("path","alias","password"));

peerConnectionServer.onConnection = (connection) -> {

        connection.onDataChannel = (dataChannel) -> {

            dataChannel.onOpen = (ev) -> {
                dataChannel.send("OPEN!");
            };

            dataChannel.onMessage = (ev) -> {
                String in = new String(ev.getData());
                dataChannel.send("echo-" + in);
            };

            dataChannel.onClose = (ev) -> {
            };

            dataChannel.onError = (ev) -> {
            };

        };
};

Run a complete selenium test

class Browser<Chrome/Firefox>*Test runs a full test against a browser. It will start the server, open the browser and connect. Then end once it has opened the WebRTC connection, or sent a bunch of messages over the peer connection.

Debug

Chrome has chrome://webrtc-internals, which is great for debugging.

Firefox has about:webrtc and tab in devtools.

TODO

• Fix SCTP to something sane (right now it is my own hack of a thing)
• Figure out why I trigger bad congestion/flow control response in browsers (see SCTP issue above)
• Look into async DTLS some more
• Scale down the excessive (but very practical) amount of copying.