diff options
Diffstat (limited to 'browser/components/doh/DoHConfig.sys.mjs')
| -rw-r--r-- | browser/components/doh/DoHConfig.sys.mjs | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/browser/components/doh/DoHConfig.sys.mjs b/browser/components/doh/DoHConfig.sys.mjs new file mode 100644 index 0000000000..a8736bdc2e --- /dev/null +++ b/browser/components/doh/DoHConfig.sys.mjs @@ -0,0 +1,342 @@ +/* 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/. */ + +/* + * 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. + */ + +import { RemoteSettings } from "resource://services-settings/remote-settings.sys.mjs"; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + Preferences: "resource://gre/modules/Preferences.sys.mjs", + Region: "resource://gre/modules/Region.sys.mjs", +}); + +const kGlobalPrefBranch = "doh-rollout"; +var kRegionPrefBranch; + +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 = `${kRegionPrefBranch}.${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 => { + let homeRegion = lazy.Preferences.get(`${kGlobalPrefBranch}.home-region`); + if (homeRegion) { + kRegionPrefBranch = `${kGlobalPrefBranch}.${homeRegion.toLowerCase()}`; + resolve(); + return; + } + + let updateRegionAndResolve = () => { + kRegionPrefBranch = `${kGlobalPrefBranch}.${lazy.Region.home.toLowerCase()}`; + lazy.Preferences.set( + `${kGlobalPrefBranch}.home-region`, + lazy.Region.home + ); + resolve(); + }; + + if (lazy.Region.home) { + updateRegionAndResolve(); + return; + } + + Services.obs.addObserver(function obs(sub, top, data) { + Services.obs.removeObserver(obs, lazy.Region.REGION_TOPIC); + updateRegionAndResolve(); + }, lazy.Region.REGION_TOPIC); + }); + + // Finally, reload config. + await this.updateFromRemoteSettings(); + }, + + async init() { + await this.loadRegion(); + + Services.prefs.addObserver(`${kGlobalPrefBranch}.`, this, true); + + 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(`${kGlobalPrefBranch}`, this); + + gProvidersCollection.off("sync", this.updateFromRemoteSettings); + gConfigCollection.off("sync", this.updateFromRemoteSettings); + + this.initComplete = new Promise(resolve => { + this._resolveInitComplete = resolve; + }); + }, + + observe(subject, topic, data) { + switch (topic) { + case kPrefChangedTopic: + let allowedPrefs = Object.getOwnPropertyNames(kConfigPrefs).map( + k => kConfigPrefs[k] + ); + if ( + !allowedPrefs.some(pref => + [ + `${kRegionPrefBranch}.${pref}`, + `${kGlobalPrefBranch}.${pref}`, + ].includes(data) + ) + ) { + break; + } + this.notifyNewConfig(); + break; + } + }, + + QueryInterface: ChromeUtils.generateQI([ + "nsIObserver", + "nsISupportsWeakReference", + ]), + + // Creates new config object from currently available + // Remote Settings values. + async updateFromRemoteSettings() { + let providers = await gProvidersCollection.get(); + let config = await gConfigCollection.get(); + + let providersById = new Map(); + providers.forEach(p => providersById.set(p.id, p)); + + let configByRegion = new Map(); + config.forEach(c => { + c.id = c.id.toLowerCase(); + configByRegion.set(c.id, c); + }); + + let homeRegion = lazy.Preferences.get(`${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(); |