gecko/dom/system/NetworkGeolocationProvider.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
Components.utils.import("resource://gre/modules/Services.jsm");

const Ci = Components.interfaces;
const Cc = Components.classes;

const POSITION_UNAVAILABLE = Ci.nsIDOMGeoPositionError.POSITION_UNAVAILABLE;
const SETTINGS_DEBUG_ENABLED = "geolocation.debugging.enabled";
const SETTINGS_CHANGED_TOPIC = "mozsettings-changed";
const SETTINGS_WIFI_ENABLED = "wifi.enabled";

let gLoggingEnabled = false;

/*
   The gLocationRequestTimeout controls how long we wait on receiving an update
   from the Wifi subsystem.  If this timer fires, we believe the Wifi scan has
   had a problem and we no longer can use Wifi to position the user this time
   around (we will continue to be hopeful that Wifi will recover).
 
   This timeout value is also used when Wifi scanning is disabled (see
   gWifiScanningEnabled).  In this case, we use this timer to collect cell/ip
   data and xhr it to the location server.
*/

let gLocationRequestTimeout = 5000;

let gWifiScanningEnabled = true;
let gCellScanningEnabled = false;

function LOG(aMsg) {
  if (gLoggingEnabled) {
    aMsg = "*** WIFI GEO: " + aMsg + "\n";
    Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService).logStringMessage(aMsg);
    dump(aMsg);
  }
}

function WifiGeoCoordsObject(lat, lon, acc, alt, altacc) {
  this.latitude = lat;
  this.longitude = lon;
  this.accuracy = acc;
  this.altitude = alt;
  this.altitudeAccuracy = altacc;
}

WifiGeoCoordsObject.prototype = {
  QueryInterface:  XPCOMUtils.generateQI([Ci.nsIDOMGeoPositionCoords])
};

function WifiGeoPositionObject(lat, lng, acc) {
  this.coords = new WifiGeoCoordsObject(lat, lng, acc, 0, 0);
  this.address = null;
  this.timestamp = Date.now();
}

WifiGeoPositionObject.prototype = {
  QueryInterface:   XPCOMUtils.generateQI([Ci.nsIDOMGeoPosition])
};

function WifiGeoPositionProvider() {
  try {
    gLoggingEnabled = Services.prefs.getBoolPref("geo.wifi.logging.enabled");
  } catch (e) {}

  try {
    gLocationRequestTimeout = Services.prefs.getIntPref("geo.wifi.timeToWaitBeforeSending");
  } catch (e) {}

  try {
    gWifiScanningEnabled = Services.prefs.getBoolPref("geo.wifi.scan");
  } catch (e) {}

  try {
    gCellScanningEnabled = Services.prefs.getBoolPref("geo.cell.scan");
  } catch (e) {}

  this.wifiService = null;
  this.timer = null;
  this.started = false;
}

WifiGeoPositionProvider.prototype = {
  classID:          Components.ID("{77DA64D3-7458-4920-9491-86CC9914F904}"),
  QueryInterface:   XPCOMUtils.generateQI([Ci.nsIGeolocationProvider,
                                           Ci.nsIWifiListener,
                                           Ci.nsITimerCallback,
                                           Ci.nsIObserver]),
  listener: null,

  observe: function(aSubject, aTopic, aData) {
    if (aTopic != SETTINGS_CHANGED_TOPIC) {
      return;
    }

    try {
      let setting = JSON.parse(aData);
      if (setting.key == SETTINGS_DEBUG_ENABLED) {
        gLoggingEnabled = setting.value;
      } else if (setting.key == SETTINGS_WIFI_ENABLED) {
        gWifiScanningEnabled = setting.value;
      }
    } catch (e) {
    }
  },

  resetTimer: function() {
    if (this.timer) {
      this.timer.cancel();
      this.timer = null;
    }
    // wifi thread triggers WifiGeoPositionProvider to proceed, with no wifi, do manual timeout
    this.timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
    this.timer.initWithCallback(this,
                                gLocationRequestTimeout,
                                this.timer.TYPE_REPEATING_SLACK);
  },

  startup:  function() {
    if (this.started)
      return;

    this.started = true;
    let self = this;
    let settingsCallback = {
      handle: function(name, result) {
        if (name == SETTINGS_DEBUG_ENABLED) {
          gLoggingEnabled = result;
        } else if (name == SETTINGS_WIFI_ENABLED) {
          gWifiScanningEnabled = result;
          if (self.wifiService) {
            self.wifiService.stopWatching(self);
          }
          if (gWifiScanningEnabled) {
            self.wifiService = Cc["@mozilla.org/wifi/monitor;1"].getService(Ci.nsIWifiMonitor);
            self.wifiService.startWatching(self);
          }
        }
      },
      
      handleError: function(message) {
        gLoggingEnabled = false;
        LOG("settings callback threw an exception, dropping");
      }
    };

    try {
      Services.obs.addObserver(this, SETTINGS_CHANGED_TOPIC, false);
      let settings = Cc["@mozilla.org/settingsService;1"].getService(Ci.nsISettingsService);
      settings.createLock().get(SETTINGS_WIFI_ENABLED, settingsCallback);
      settings.createLock().get(SETTINGS_DEBUG_ENABLED, settingsCallback);
    } catch(ex) {
      // This platform doesn't have the settings interface, and that is just peachy
    }

    if (gWifiScanningEnabled && Cc["@mozilla.org/wifi/monitor;1"]) {
      if (this.wifiService) {
        this.wifiService.stopWatching(this);
      }
      this.wifiService = Cc["@mozilla.org/wifi/monitor;1"].getService(Ci.nsIWifiMonitor);
      this.wifiService.startWatching(this);
    }

    this.resetTimer();
    LOG("startup called.");
  },

  watch: function(c) {
    this.listener = c;
  },

  shutdown: function() {
    LOG("shutdown called");
    if (this.started == false) {
      return;
    }

    if (this.timer) {
      this.timer.cancel();
      this.timer = null;
    }

    if(this.wifiService) {
      this.wifiService.stopWatching(this);
      this.wifiService = null;
    }

    Services.obs.removeObserver(this, SETTINGS_CHANGED_TOPIC);

    this.listener = null;
    this.started = false;
  },

  setHighAccuracy: function(enable) {
  },

  onChange: function(accessPoints) {

    // we got some wifi data, rearm the timer.
    this.resetTimer();

    function isPublic(ap) {
      let mask = "_nomap"
      let result = ap.ssid.indexOf(mask, ap.ssid.length - mask.length);
      if (result != -1) {
        LOG("Filtering out " + ap.ssid + " " + result);
      }
      return result;
    };

    function sort(a, b) {
      return b.signal - a.signal;
    };

    function encode(ap) {
      return { 'macAddress': ap.mac, 'signalStrength': ap.signal };
    };

    let wifiData = null;
    if (accessPoints) {
      wifiData = accessPoints.filter(isPublic).sort(sort).map(encode);
    }
    this.sendLocationRequest(wifiData);
  },

  onError: function (code) {
    LOG("wifi error: " + code);
    this.sendLocationRequest(null);
  },

  getMobileInfo: function() {
    LOG("updateMobileInfo called");
    try {
      let radioService = Cc["@mozilla.org/ril;1"]
                    .getService(Ci.nsIRadioInterfaceLayer);
      let numInterfaces = radioService.numRadioInterfaces;
      let result = [];
      for (let i = 0; i < numInterfaces; i++) {
        LOG("Looking for SIM in slot:" + i + " of " + numInterfaces);
        let radio = radioService.getRadioInterface(i);
        let iccInfo = radio.rilContext.iccInfo;
        let cell = radio.rilContext.voice.cell;

        if (iccInfo && cell) {
          // TODO type and signal strength
          result.push({ radio: "gsm",
                      mobileCountryCode: iccInfo.mcc,
                      mobileNetworkCode: iccInfo.mnc,
                      locationAreaCode: cell.gsmLocationAreaCode,
                      cellId: cell.gsmCellId });
        }
      }
      return result;
    } catch (e) {
      return null;
    }
  },

  notify: function (timer) {
    this.sendLocationRequest(null);
  },

  sendLocationRequest: function (wifiData) {
    let url = Services.urlFormatter.formatURLPref("geo.wifi.uri");
    let listener = this.listener;
    LOG("Sending request: " + url + "\n");

    let xhr = Components.classes["@mozilla.org/xmlextras/xmlhttprequest;1"]
                        .createInstance(Ci.nsIXMLHttpRequest);

    listener.locationUpdatePending();

    try {
      xhr.open("POST", url, true);
    } catch (e) {
      listener.notifyError(POSITION_UNAVAILABLE);
      return;
    }
    xhr.setRequestHeader("Content-Type", "application/json; charset=UTF-8");
    xhr.responseType = "json";
    xhr.mozBackgroundRequest = true;
    xhr.channel.loadFlags = Ci.nsIChannel.LOAD_ANONYMOUS;
    xhr.onerror = function() {
      listener.notifyError(POSITION_UNAVAILABLE);
    };
    xhr.onload = function() {
      LOG("gls returned status: " + xhr.status + " --> " +  JSON.stringify(xhr.response));
      if ((xhr.channel instanceof Ci.nsIHttpChannel && xhr.status != 200) ||
          !xhr.response || !xhr.response.location) {
        listener.notifyError(POSITION_UNAVAILABLE);
        return;
      }

      let newLocation = new WifiGeoPositionObject(xhr.response.location.lat,
                                                  xhr.response.location.lng,
                                                  xhr.response.accuracy);

      listener.update(newLocation);
    };

    let data = {};
    if (wifiData) {
      data.wifiAccessPoints = wifiData;
    }

    if (gCellScanningEnabled) {
      let cellData = this.getMobileInfo();
      if (cellData) {
        data.cellTowers = cellData;
      }
    }

    data = JSON.stringify(data);
    LOG("sending " + data);
    xhr.send(data);
  },
};

this.NSGetFactory = XPCOMUtils.generateNSGetFactory([WifiGeoPositionProvider]);