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/* 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
/*
* This module provides an interface to access DoH configuration - e.g. whether
* DoH is enabled, whether capabilities are enabled, etc. The configuration is
* sourced from either Remote Settings or pref values, with Remote Settings
* being preferred.
*/
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
Preferences: "resource://gre/modules/Preferences.sys.mjs",
Region: "resource://gre/modules/Region.sys.mjs",
});
const kGlobalPrefBranch = "doh-rollout";
function regionPrefBranch() {
let homeRegion = lazy.Preferences.get(`${kGlobalPrefBranch}.home-region`);
if (!homeRegion) {
return undefined;
}
return `${kGlobalPrefBranch}.${homeRegion.toLowerCase()}`;
}
function currentRegion() {
if (lazy.Region.current) {
return lazy.Region.current;
}
return lazy.Region.home;
}
const kConfigPrefs = {
kEnabledPref: "enabled",
kProvidersPref: "provider-list",
kTRRSelectionEnabledPref: "trr-selection.enabled",
kTRRSelectionProvidersPref: "trr-selection.provider-list",
kTRRSelectionCommitResultPref: "trr-selection.commit-result",
kProviderSteeringEnabledPref: "provider-steering.enabled",
kProviderSteeringListPref: "provider-steering.provider-list",
};
const kPrefChangedTopic = "nsPref:changed";
const gProvidersCollection = RemoteSettings("doh-providers");
const gConfigCollection = RemoteSettings("doh-config");
function getPrefValueRegionFirst(prefName) {
let regionalPrefName = `${regionPrefBranch()}.${prefName}`;
let regionalPrefValue = lazy.Preferences.get(regionalPrefName);
if (regionalPrefValue !== undefined) {
return regionalPrefValue;
}
return lazy.Preferences.get(`${kGlobalPrefBranch}.${prefName}`);
}
function getProviderListFromPref(prefName) {
let prefVal = getPrefValueRegionFirst(prefName);
if (prefVal) {
try {
return JSON.parse(prefVal);
} catch (e) {
console.error(`DoH provider list not a valid JSON array: ${prefName}`);
}
}
return undefined;
}
// Generate a base config object with getters that return pref values. When
// Remote Settings values become available, a new config object will be
// generated from this and specific fields will be replaced by the RS value.
// If we use a class to store base config and instantiate new config objects
// from it, we lose the ability to override getters because they are defined
// as non-configureable properties on class instances. So just use a function.
function makeBaseConfigObject() {
function makeConfigProperty({
obj,
propName,
defaultVal,
prefName,
isProviderList,
}) {
let prefFn = isProviderList
? getProviderListFromPref
: getPrefValueRegionFirst;
let overridePropName = "_" + propName;
Object.defineProperty(obj, propName, {
get() {
// If a pref value exists, it gets top priority. Otherwise, if it has an
// explicitly set value (from Remote Settings), we return that.
let prefVal = prefFn(prefName);
if (prefVal !== undefined) {
return prefVal;
}
if (this[overridePropName] !== undefined) {
return this[overridePropName];
}
return defaultVal;
},
set(val) {
this[overridePropName] = val;
},
});
}
let newConfig = {
get fallbackProviderURI() {
return this.providerList[0]?.uri;
},
trrSelection: {},
providerSteering: {},
};
makeConfigProperty({
obj: newConfig,
propName: "enabled",
defaultVal: false,
prefName: kConfigPrefs.kEnabledPref,
isProviderList: false,
});
makeConfigProperty({
obj: newConfig,
propName: "providerList",
defaultVal: [],
prefName: kConfigPrefs.kProvidersPref,
isProviderList: true,
});
makeConfigProperty({
obj: newConfig.trrSelection,
propName: "enabled",
defaultVal: false,
prefName: kConfigPrefs.kTRRSelectionEnabledPref,
isProviderList: false,
});
makeConfigProperty({
obj: newConfig.trrSelection,
propName: "commitResult",
defaultVal: false,
prefName: kConfigPrefs.kTRRSelectionCommitResultPref,
isProviderList: false,
});
makeConfigProperty({
obj: newConfig.trrSelection,
propName: "providerList",
defaultVal: [],
prefName: kConfigPrefs.kTRRSelectionProvidersPref,
isProviderList: true,
});
makeConfigProperty({
obj: newConfig.providerSteering,
propName: "enabled",
defaultVal: false,
prefName: kConfigPrefs.kProviderSteeringEnabledPref,
isProviderList: false,
});
makeConfigProperty({
obj: newConfig.providerSteering,
propName: "providerList",
defaultVal: [],
prefName: kConfigPrefs.kProviderSteeringListPref,
isProviderList: true,
});
return newConfig;
}
export const DoHConfigController = {
initComplete: null,
_resolveInitComplete: null,
// This field always contains the current config state, for
// consumer use.
currentConfig: makeBaseConfigObject(),
// Loads the client's region via Region.sys.mjs. This might mean waiting
// until the region is available.
async loadRegion() {
await new Promise(resolve => {
// If the region has changed since it was last set, update the pref.
let homeRegionChanged = lazy.Preferences.get(
`${kGlobalPrefBranch}.home-region-changed`
);
if (homeRegionChanged) {
lazy.Preferences.reset(`${kGlobalPrefBranch}.home-region-changed`);
lazy.Preferences.reset(`${kGlobalPrefBranch}.home-region`);
}
let homeRegion = lazy.Preferences.get(`${kGlobalPrefBranch}.home-region`);
if (homeRegion) {
resolve();
return;
}
let updateRegionAndResolve = () => {
lazy.Preferences.set(
`${kGlobalPrefBranch}.home-region`,
currentRegion()
);
resolve();
};
if (currentRegion()) {
updateRegionAndResolve();
return;
}
Services.obs.addObserver(function obs() {
Services.obs.removeObserver(obs, lazy.Region.REGION_TOPIC);
updateRegionAndResolve();
}, lazy.Region.REGION_TOPIC);
});
// Finally, reload config.
await this.updateFromRemoteSettings();
},
async init() {
await this.loadRegion();
Services.prefs.addObserver(`${kGlobalPrefBranch}.`, this, true);
Services.obs.addObserver(this, "idle-daily", true);
Services.obs.addObserver(this, "default-timezone-changed", true);
gProvidersCollection.on("sync", this.updateFromRemoteSettings);
gConfigCollection.on("sync", this.updateFromRemoteSettings);
this._resolveInitComplete();
},
// Useful for tests to set prior state before init()
async _uninit() {
await this.initComplete;
Services.prefs.removeObserver(`${kGlobalPrefBranch}`, this);
Services.obs.removeObserver(this, "idle-daily");
Services.obs.removeObserver(this, "default-timezone-changed");
gProvidersCollection.off("sync", this.updateFromRemoteSettings);
gConfigCollection.off("sync", this.updateFromRemoteSettings);
this.initComplete = new Promise(resolve => {
this._resolveInitComplete = resolve;
});
},
// Performs a region check when the timezone changes
async getRegionAndNotify() {
await lazy.Region._fetchRegion();
if (
currentRegion() &&
currentRegion() !=
lazy.Preferences.get(`${kGlobalPrefBranch}.home-region`)
) {
lazy.Preferences.set(`${kGlobalPrefBranch}.home-region`, currentRegion());
this.notifyNewConfig();
}
},
observe(subject, topic, data) {
switch (topic) {
case kPrefChangedTopic:
let allowedPrefs = Object.getOwnPropertyNames(kConfigPrefs).map(
k => kConfigPrefs[k]
);
if (
!allowedPrefs.some(pref =>
[
`${regionPrefBranch()}.${pref}`,
`${kGlobalPrefBranch}.${pref}`,
].includes(data)
)
) {
break;
}
this.notifyNewConfig();
break;
case "idle-daily":
if (
currentRegion() &&
currentRegion() !=
lazy.Preferences.get(`${kGlobalPrefBranch}.home-region`)
) {
lazy.Preferences.set(
`${kGlobalPrefBranch}.home-region`,
currentRegion()
);
this.notifyNewConfig();
}
break;
case "default-timezone-changed":
this.getRegionAndNotify();
break;
}
},
QueryInterface: ChromeUtils.generateQI([
"nsIObserver",
"nsISupportsWeakReference",
]),
// Creates new config object from currently available
// Remote Settings values.
async updateFromRemoteSettings() {
let providers = await gProvidersCollection.get();
let config = await gConfigCollection.get();
let providersById = new Map();
providers.forEach(p => providersById.set(p.id, p));
let configByRegion = new Map();
config.forEach(c => {
c.id = c.id.toLowerCase();
configByRegion.set(c.id, c);
});
let homeRegion = lazy.Preferences.get(`${kGlobalPrefBranch}.home-region`);
let localConfig =
configByRegion.get(homeRegion?.toLowerCase()) ||
configByRegion.get("global");
// Make a new config object first, mutate it as needed, then synchronously
// replace the currentConfig object at the end to ensure atomicity.
let newConfig = makeBaseConfigObject();
if (!localConfig) {
DoHConfigController.currentConfig = newConfig;
DoHConfigController.notifyNewConfig();
return;
}
if (localConfig.rolloutEnabled) {
newConfig.enabled = true;
}
let parseProviderList = (list, checkFn) => {
let parsedList = [];
list?.split(",")?.forEach(p => {
p = p.trim();
if (!p.length) {
return;
}
p = providersById.get(p);
if (!p || (checkFn && !checkFn(p))) {
return;
}
parsedList.push(p);
});
return parsedList;
};
let regionalProviders = parseProviderList(localConfig.providers);
if (regionalProviders?.length) {
newConfig.providerList = regionalProviders;
}
if (localConfig.steeringEnabled) {
let steeringProviders = parseProviderList(
localConfig.steeringProviders,
p => p.canonicalName?.length
);
if (steeringProviders?.length) {
newConfig.providerSteering.providerList = steeringProviders;
newConfig.providerSteering.enabled = true;
}
}
if (localConfig.autoDefaultEnabled) {
let defaultProviders = parseProviderList(
localConfig.autoDefaultProviders
);
if (defaultProviders?.length) {
newConfig.trrSelection.providerList = defaultProviders;
newConfig.trrSelection.enabled = true;
}
}
// Finally, update the currentConfig object synchronously.
DoHConfigController.currentConfig = newConfig;
DoHConfigController.notifyNewConfig();
},
kConfigUpdateTopic: "doh-config-updated",
notifyNewConfig() {
Services.obs.notifyObservers(null, this.kConfigUpdateTopic);
},
};
DoHConfigController.initComplete = new Promise(resolve => {
DoHConfigController._resolveInitComplete = resolve;
});
DoHConfigController.init();