NDN-Gremlin

NDN-Gremlin is a small, programmable Named Data Networking forwarding module for Node.js and the browser (via browserify). Use it to prototype NDN applications and experiment with network structures in pure Javascript.

Programmatic API features:

• connect to other gremlins via websocket, webrtc, and tcp
• listen for connection requests along a given namespace (in-band webrtc signaling)
• callback based interest listeners (blocking or non-blocking)
• interest/data forwarding and caching

for full list of methods, see the documentation

Usage

Note: NDN-gremlin is a bare-bones module providing low level interfaces to allow for the creation of highly customized forwarders. If you want to prototype an application really quickly, use NDN-IO, which includes a pre-configured gremlin, repository, and NDN Input/Output abstraction

Rather than provide a daemon to run from the command line, this 'gremlin' is designed to be used as a forwarding module within the context of a Node.js or Web-app.

Let's say you want a little gremlin running on the server, and you want clients in the browser to connect to it and be able to register a prefix on the server.

Currently, ndn-gremlin simply allows you to set a registrationPrefix on the client side and add a listener for that prefix on the remote side. Since the addition of a signed interest API in NDN-js, future versions will see a prefix-registration protocol more in line with that of NFD

In Node:

var Gremlin = require("ndn-gremlin")
  , gremlin = new Gremlin({
      ws: 1337     // default: 8585
      , tcp: 5555  // default: 8484
    });

gremlin.addListener({
    prefix: "myPrefix/register-prefix"
    , blocking: true
  }, function(interest, faceID, unblock){
    // interest.name.toUri() == "myPrefix/register-prefix/prefix/To/Register"
    gremlin.addRegisteredPrefix(interest.name.getSubName(2).toUri(), faceID)
  })

In the Browser:

var Gremlin = require("ndn-gremlin")
  , gremlin = new Gremlin();

gremlin.setRegistrationPrefix("myPrefix/register-prefix")

gremlin.addConnection("ws://" + location.hostname + ":1337", function onOpen(faceID){
    console.log("face " + faceId + "opened");
    gremlin.registerPrefix("prefix/To/Register", faceID);
  }, function onClosed(faceId){
    console.log("face " + faceId + "closed");
  });

Now lets say you want your clients to use your NDN network as a signaling channel for webRTC datachannels:

client 1:

var maxConnectionsOnPrefix = 3
gremlin.addConnectionListener("webrtc/ndn/", maxConnectionsOnPrefix, function onNewFace(faceID){
  console.log("got new webRTC face " + faceID);
  })

client 2:

gremlin.requestConnection("webrtc/ndn", function onOpen(faceID){
  console.log("got new face from connection request!" + faceID);
  })

License

Copywrite Colorado State University; Ryan Bennett.

LGPLv3