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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
"use strict";
/* globals browser, module */
class UAOverrides {
constructor(availableOverrides) {
this.OVERRIDE_PREF = "perform_ua_overrides";
this._overridesEnabled = true;
this._availableOverrides = availableOverrides;
this._activeListeners = new Map();
}
bindAboutCompatBroker(broker) {
this._aboutCompatBroker = broker;
}
bootup() {
browser.aboutConfigPrefs.onPrefChange.addListener(() => {
this.checkOverridePref();
}, this.OVERRIDE_PREF);
this.checkOverridePref();
}
checkOverridePref() {
browser.aboutConfigPrefs.getPref(this.OVERRIDE_PREF).then(value => {
if (value === undefined) {
browser.aboutConfigPrefs.setPref(this.OVERRIDE_PREF, true);
} else if (value === false) {
this.unregisterUAOverrides();
} else {
this.registerUAOverrides();
}
});
}
getAvailableOverrides() {
return this._availableOverrides;
}
isEnabled() {
return this._overridesEnabled;
}
enableOverride(override) {
if (override.active) {
return;
}
const { blocks, matches, uaTransformer } = override.config;
const listener = details => {
// Don't actually override the UA for an experiment if the user is not
// part of the experiment (unless they force-enabed the override).
if (
!override.config.experiment ||
override.permanentPrefEnabled === true
) {
for (const header of details.requestHeaders) {
if (header.name.toLowerCase() === "user-agent") {
// Don't override the UA if we're on a mobile device that has the
// "Request Desktop Site" mode enabled. The UA for the desktop mode
// is set inside Gecko with a simple string replace, so we can use
// that as a check, see https://searchfox.org/mozilla-central/rev/89d33e1c3b0a57a9377b4815c2f4b58d933b7c32/mobile/android/chrome/geckoview/GeckoViewSettingsChild.js#23-28
let isMobileWithDesktopMode =
override.currentPlatform == "android" &&
header.value.includes("X11; Linux x86_64");
if (!isMobileWithDesktopMode) {
header.value = uaTransformer(
header.value,
override.currentPlatform
);
}
}
}
}
return { requestHeaders: details.requestHeaders };
};
browser.webRequest.onBeforeSendHeaders.addListener(
listener,
{ urls: matches },
["blocking", "requestHeaders"]
);
const listeners = { onBeforeSendHeaders: listener };
if (blocks) {
const blistener = () => {
return { cancel: true };
};
browser.webRequest.onBeforeRequest.addListener(
blistener,
{ urls: blocks },
["blocking"]
);
listeners.onBeforeRequest = blistener;
}
this._activeListeners.set(override, listeners);
override.active = true;
}
onOverrideConfigChanged(override) {
// Check whether the override should be hidden from about:compat.
override.hidden = override.config.hidden;
// Setting the override's permanent pref overrules whether it is hidden.
if (override.permanentPrefEnabled !== undefined) {
override.hidden = !override.permanentPrefEnabled;
}
// Also check whether the override should be active.
let shouldBeActive = true;
// Overrides can be force-deactivated by their permanent preference.
if (override.permanentPrefEnabled === false) {
shouldBeActive = false;
}
// Overrides gated behind an experiment the user is not part of do not
// have to be activated, unless they are gathering telemetry, or the
// user has force-enabled them with their permanent pref.
if (override.config.experiment && override.permanentPrefEnabled !== true) {
shouldBeActive = false;
}
if (shouldBeActive) {
this.enableOverride(override);
} else {
this.disableOverride(override);
}
if (this._overridesEnabled) {
this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
overridesChanged: this._aboutCompatBroker.filterOverrides(
this._availableOverrides
),
});
}
}
async registerUAOverrides() {
const platformMatches = ["all"];
const { os } = await browser.runtime.getPlatformInfo();
platformMatches.push(os);
platformMatches.push(os == "android" ? "android" : "desktop");
for (const override of this._availableOverrides) {
if (platformMatches.includes(override.platform)) {
override.availableOnPlatform = true;
override.currentPlatform = os;
// If there is a specific about:config preference governing
// this override, monitor its state.
const pref = override.config.permanentPref;
override.permanentPrefEnabled =
pref && (await browser.aboutConfigPrefs.getPref(pref));
if (pref) {
const checkOverridePref = () => {
browser.aboutConfigPrefs.getPref(pref).then(value => {
override.permanentPrefEnabled = value;
this.onOverrideConfigChanged(override);
});
};
browser.aboutConfigPrefs.onPrefChange.addListener(
checkOverridePref,
pref
);
}
this.onOverrideConfigChanged(override);
}
}
this._overridesEnabled = true;
this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
overridesChanged: this._aboutCompatBroker.filterOverrides(
this._availableOverrides
),
});
}
unregisterUAOverrides() {
for (const override of this._availableOverrides) {
this.disableOverride(override);
}
this._overridesEnabled = false;
this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
overridesChanged: false,
});
}
disableOverride(override) {
if (!override.active) {
return;
}
const listeners = this._activeListeners.get(override);
for (const [name, listener] of Object.entries(listeners)) {
browser.webRequest[name].removeListener(listener);
}
override.active = false;
this._activeListeners.delete(override);
}
}
module.exports = UAOverrides;