gecko/netwerk/protocol/http/UserAgentOverrides.jsm

183 lines
5.2 KiB
JavaScript

/* 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/. */
"use strict";
this.EXPORTED_SYMBOLS = [ "UserAgentOverrides" ];
const Ci = Components.interfaces;
const Cc = Components.classes;
Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
Components.utils.import("resource://gre/modules/Services.jsm");
Components.utils.import("resource://gre/modules/UserAgentUpdates.jsm");
const OVERRIDE_MESSAGE = "Useragent:GetOverride";
const PREF_OVERRIDES_ENABLED = "general.useragent.site_specific_overrides";
const DEFAULT_UA = Cc["@mozilla.org/network/protocol;1?name=http"]
.getService(Ci.nsIHttpProtocolHandler)
.userAgent;
const MAX_OVERRIDE_FOR_HOST_CACHE_SIZE = 250;
XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
"@mozilla.org/parentprocessmessagemanager;1",
"nsIMessageListenerManager"); // Might have to make this broadcast?
var gPrefBranch;
var gOverrides = new Map;
var gUpdatedOverrides;
var gOverrideForHostCache = new Map;
var gInitialized = false;
var gOverrideFunctions = [
function (aHttpChannel) UserAgentOverrides.getOverrideForURI(aHttpChannel.URI)
];
var gBuiltUAs = new Map;
this.UserAgentOverrides = {
init: function uao_init() {
if (gInitialized)
return;
gPrefBranch = Services.prefs.getBranch("general.useragent.override.");
gPrefBranch.addObserver("", buildOverrides, false);
ppmm.addMessageListener(OVERRIDE_MESSAGE, this);
Services.prefs.addObserver(PREF_OVERRIDES_ENABLED, buildOverrides, false);
try {
Services.obs.addObserver(HTTP_on_modify_request, "http-on-modify-request", false);
} catch (x) {
// The http-on-modify-request notification is disallowed in content processes.
}
UserAgentUpdates.init(function(overrides) {
gOverrideForHostCache.clear();
if (overrides) {
for (let domain in overrides) {
overrides[domain] = getUserAgentFromOverride(overrides[domain]);
}
overrides.get = function(key) this[key];
}
gUpdatedOverrides = overrides;
});
buildOverrides();
gInitialized = true;
},
addComplexOverride: function uao_addComplexOverride(callback) {
// Add to front of array so complex overrides have precedence
gOverrideFunctions.unshift(callback);
},
getOverrideForURI: function uao_getOverrideForURI(aURI) {
let host = aURI.asciiHost;
if (!gInitialized ||
(!gOverrides.size && !gUpdatedOverrides) ||
!(host)) {
return null;
}
let override = gOverrideForHostCache.get(host);
if (override !== undefined)
return override;
function findOverride(overrides) {
let searchHost = host;
let userAgent = overrides.get(searchHost);
while (!userAgent) {
let dot = searchHost.indexOf('.');
if (dot === -1) {
return null;
}
searchHost = searchHost.slice(dot + 1);
userAgent = overrides.get(searchHost);
}
return userAgent;
}
override = (gOverrides.size && findOverride(gOverrides))
|| (gUpdatedOverrides && findOverride(gUpdatedOverrides));
if (gOverrideForHostCache.size >= MAX_OVERRIDE_FOR_HOST_CACHE_SIZE) {
gOverrideForHostCache.clear();
}
gOverrideForHostCache.set(host, override);
return override;
},
uninit: function uao_uninit() {
if (!gInitialized)
return;
gInitialized = false;
gPrefBranch.removeObserver("", buildOverrides);
Services.prefs.removeObserver(PREF_OVERRIDES_ENABLED, buildOverrides);
Services.obs.removeObserver(HTTP_on_modify_request, "http-on-modify-request");
},
receiveMessage: function(aMessage) {
let name = aMessage.name;
switch (name) {
case OVERRIDE_MESSAGE:
let uri = aMessage.data.uri;
return this.getOverrideForURI(uri);
default:
throw("Wrong Message in UserAgentOverride: " + name);
}
}
};
function getUserAgentFromOverride(override)
{
let userAgent = gBuiltUAs.get(override);
if (userAgent !== undefined) {
return userAgent;
}
let [search, replace] = override.split("#", 2);
if (search && replace) {
userAgent = DEFAULT_UA.replace(new RegExp(search, "g"), replace);
} else {
userAgent = override;
}
gBuiltUAs.set(override, userAgent);
return userAgent;
}
function buildOverrides() {
gOverrides.clear();
gOverrideForHostCache.clear();
if (!Services.prefs.getBoolPref(PREF_OVERRIDES_ENABLED))
return;
let builtUAs = new Map;
let domains = gPrefBranch.getChildList("");
for (let domain of domains) {
let override = gPrefBranch.getCharPref(domain);
let userAgent = getUserAgentFromOverride(override);
if (userAgent != DEFAULT_UA) {
gOverrides.set(domain, userAgent);
}
}
}
function HTTP_on_modify_request(aSubject, aTopic, aData) {
let channel = aSubject.QueryInterface(Ci.nsIHttpChannel);
for (let callback of gOverrideFunctions) {
let modifiedUA = callback(channel, DEFAULT_UA);
if (modifiedUA) {
channel.setRequestHeader("User-Agent", modifiedUA, false);
return;
}
}
}