Remote Network Driver Interface Specification，既是RemoteNDIS，既是远程网络驱动接口规范。基于USB实现RNDIS实际上就是TCP/IP over USB，就是在USB设备上跑TCP/IP，让USB设备看上去像一块网卡。^[1]

Hotspot.html (gaia\apps\settings\elements)      1910         2014/12/1

<input type="checkbox" name="tethering.usb.enabled" class="uninit">

handleEvent: function settings_handleEvent(event)

==》

value = input.checked; // boolean

==》

var cset = {}; cset[key] = value;

settings.createLock().set(cset);

case TOPIC_MOZSETTINGS_CHANGED:

let setting = JSON.parse(data);

this.handle(setting.key, setting.value);

break;

XPCOMUtils.defineLazyServiceGetter(this, "gNetworkService",

                                   "@mozilla.org/network/service;1",

                                   "nsINetworkService");

component {c14cabaf-bb8e-470d-a2f1-2cb6de6c5e5c} NetworkService.js

contract @mozilla.org/network/service;1 {c14cabaf-bb8e-470d-a2f1-2cb6de6c5e5c}

// Switch usb function by modifying property of persist.sys.usb.config.

enableUsbRndis: function(enable, callback) {

if(DEBUG) debug("enableUsbRndis: " + enable);

let params = {

cmd: "enableUsbRndis",

enable: enable

};

// Ask net work to report the result when this value is set to true.

if (callback) {

params.report = true;

} else {

params.report = false;

}

// The callback function in controlMessage may not be fired immediately.

params.isAsync = true;

//this._usbTetheringAction = TETHERING_STATE_ONGOING;

this.controlMessage(params, function(data) {

callback.enableUsbRndisResult(data.result, data.enable);

});

},

controlMessage: function(params, callback) {

if (this.shutdown) {

return;

}

if (callback) {

let id = this.idgen++;

params.id = id;

this.controlCallbacks[id] = callback;

}

if (gNetworkWorker) {

gNetworkWorker.postMessage(params);

}

},

enableUsbRndisResult: function(success, enable) {

if (success) {

// If enable is false, don't find usb interface cause it is already down,

// just use the internal interface in settings.

if (enable) {

this._tetheringInterface[TETHERING_TYPE_USB].internalInterface = this.getUsbInterface();

}

this.setUSBTethering(enable,

this._tetheringInterface[TETHERING_TYPE_USB],

this.usbTetheringResultReport.bind(this));

} else {

this.usbTetheringResultReport("Failed to set usb function");

throw new Error("failed to set USB Function to adb");

}

},

XPCOMUtils.defineLazyServiceGetter(this, "gNetworkWorker",

                                   "@mozilla.org/network/worker;1",

                                   "nsINetworkWorker");

static const mozilla::Module::ContractIDEntry kNetworkWorkerContracts[] = {

{ "@mozilla.org/network/worker;1", &kNS_NETWORKWORKER_CID },

{ nullptr }

};