fxos HTTP-SMS-Gateway slides

Transforming a Firefox OS Phone into a SMS Gateway Server

What's this?

An SMS gateway allows a computer to send or receive Short Message Service (SMS) transmissions to or from a telecommunications network.

This is a fully functional HTTP-SMS-Gateway server that runs on any device supporting Firefox OS (FxOS).

#→ Why a FxOS based SMS gateway?

There are many ways to hack together a SMS gateway server…

You can do a SMS gateway like this

A Raspberry Pi with a Adafruit FONA - Mini Cellular GSM Breakout Board connected.

Or you can do a SMS gateway like this

A Raspberry Pi with a Nokia 3310 connected.

Or like this

A Geeksphone Keon.

So, why did I do this?

I wanted to show that FxOS is more than a mobile phone OS
A SMS gateway involves many parts of a mobile phone "dev board" ;)
It's easy to implement
I already knowed most of the things from my Firefox OS washing machine project ;)

Ok got it, but why FxOS?

Firefox OS devices as general purpose dev boards
It's just JavaScript
Rapid prototyping
Lot's of resources and frameworks available because of JavaScript

In detail

Firefox OS: Dev board with WiFi, Touchscreen, Bluetooth, Cellular Connection, Hardware Buttons and much more for round about 50 Euro
There are frameworks for Web Server, Simple Service Discovery, Physical Web, Web Bluetooth ... you name it
The main network connection and SMS gateway logic requires 600 lines of code

How does it work?

Firefox OS is based on three parts, Gonk, Gecko and Gaia
Gonk contains the kernel, hardware abstraction layer and other low-level components
Gecko is the application platform layer running all JavaScript and rendering stuff
Gaia is the main thing that makes up Firefox OS

This gateway server replaces Gaia and with it's own code.

If the device get's power connection, it will instantly boot up
There's no way to shut it down (no one can by mistake shut it off)
The server will work with wifi or cellular connection
The connection has to be configured by putting a settings.json file in the root folder of the devices sd-card
If connection is established, it starts a HTTP server running the REST-ful API
On request, it sends a SMS to the given number and responds the status

Main parts of the server

Parsing the cellular and wifi config
Connect to cellular and wifi network
Start a HTTP server
Send SMS from web request
Respond with the send status

Parsing the cellular and wifi config

This is how the settings file on the sd-card looks like:

{
  "wifi": {
    "enabled": true,
    "network": "YOUR_SSID",
    "password": "YOUR_WIFI_PASSWORD"
  },
  "cellular": {
    "roaming": false,
    "edgeOnly": false,
    "pin": "0000"
  }
}

Determine which sd-card contains the file:

var volumes = navigator.getDeviceStorages('sdcard');
volumes.forEach(volume => {
  var request = volume.get('settings.json');
  request.onsuccess = sdcard => {
    // load settings
  };
});

Internal storage may also be available as sdcard!

Load the settings from the file:

request.onsuccess = () => {
  var reader = new FileReader();
  reader.onload = e => {
    var config = JSON.parse(e.target.result);
    // do something with the config
  };
  reader.readAsText(request.result);
};

Connect to cellular network

Enable a connection for every SIM card (there may be more than one)

[].forEach.call(navigator.mozMobileConnections, conn => {
  conn.setPreferredNetworkType(config.cellular.edgeOnly ? 'gsm' : 'wcdma/gsm-auto');
  conn.setRadioEnabled(true);
});

There's some more code necessary for handling error cases or SIM unlocking if it is secured by a PIN. You will find it in the repository on Github.

Connect to wifi network

var n = navigator.mozWifiManager.getNetworks();
n.onsuccess = () => {
  var wifi = n.result.filter(w => w.ssid === config.wifi.network)[0];
  if (wifi.security.length > 0 && wifi.security[0] === 'WPA-PSK') {
    wifi.keyManagement = 'WPA-PSK';
    wifi.psk = config.wifi.password;
  }
  navigator.mozWifiManager.associate(wifi);
};

Start a HTTP server

navigator.mozWifiManager.onconnectioninfoupdate = e => {
  var httpServer = new HTTPServer(80);
  httpServer.addEventListener('request', evt => {
    evt.response.headers['Content-Type'] = 'application/json';
    evt.response.send('{"message":"Hello World!"}');
  });
  console.log('http://' + e.ipAddress + ':80/');
};

The server implementation is based on https://hacks.mozilla.org/2015/02/embedding-an-http-web-server-in-firefox-os/

Send SMS from web request

httpServer.addEventListener('request', evt => {
  if (evt.request.path === '/send') {
    var sms = navigator.mozMobileMessage.send(
      request.params.number,
      request.params.message
    );
    sms.onsuccess = () => {
      response.send('{"message":"Message sent successfully"}');
    };
    sms.onerror = () => {
      response.send('{"message":"Error: ' + sms.error + '"}');
    };
  }
});

Get it

You can find the source code for this gateway server on Github: https://github.com/SunboX/fxos-HTTP-SMS-Gateway

Most of the server's logic can be found inside the /apps/system/js folder.

What's next?

You should really try to hack on Firefox OS yourself

Not only like "hacking apps" or add-ons, but also hacking Firefox OS itself. It's open, free and easy to start building great things with it. There's even cheap hardware all around, with sensors, cameras, bluetooth, wifi, gps ... things you can't get this easy with your famous hacker board.

`<Thank You!>`

contact: [email protected]

twitter @sonnenkiste
github github.com/SunboX
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SunboX/fxos-HTTP-SMS-Gateway.md