Layer2 

layer2 leverages Node.js' built-in [streams][] to provide an intuitive and
efficient interface to the [data link layer][wiki]. It supports frame capture
and injection, and provides decoders for various link types.

``javascript
var layer2 = require('layer2');

var capture = new layer2.capture.Live('en0', {monitor: true});
var decoder = new layer2.Decoder();

capture // Stream of buffers (frames' raw bytes).
.pipe(decoder) // Stream of objects (decoded frames).
.on('data', function (frame) { console.log(JSON.stringify(frame)); });
`

Installation

`bash
$ npm install layer2
`

layer2 depends on [libpcap][]. Note that you might also need to run live
captures as root.

Documentation

API docs and several examples are available.

Benchmarks

layer2 is built with both ease of use and performance in mind. This means you
can benefit from the productivity gains of writing JavaScript and still handle
throughput rates of several hundred thousand frames per second (upwards of a
million when streaming raw frames). You can read more about this on the
benchmarks page.

Tests

`bash
$ npm test
``

Some tests require an active internet connection.

[wiki]: http://en.wikipedia.org/wiki/Data_link_layer
[Radiotap]: http://www.radiotap.org/
[streams]: http://nodejs.org/api/stream.html
[libpcap]: http://www.tcpdump.org/
[node_pcap]: https://github.com/mranney/node_pcap
[pcap-stream]: https://github.com/wanderview/node-pcap-stream