gecko/toolkit/components/url-classifier/content/xml-fetcher.js
2011-09-29 12:06:36 -04:00

234 lines
7.7 KiB
JavaScript

# ***** BEGIN LICENSE BLOCK *****
# Version: MPL 1.1/GPL 2.0/LGPL 2.1
#
# The contents of this file are subject to the Mozilla Public License Version
# 1.1 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
# for the specific language governing rights and limitations under the
# License.
#
# The Original Code is Google Safe Browsing.
#
# The Initial Developer of the Original Code is Google Inc.
# Portions created by the Initial Developer are Copyright (C) 2006
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Fritz Schneider <fritz@google.com> (original author)
#
# Alternatively, the contents of this file may be used under the terms of
# either the GNU General Public License Version 2 or later (the "GPL"), or
# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
# in which case the provisions of the GPL or the LGPL are applicable instead
# of those above. If you wish to allow use of your version of this file only
# under the terms of either the GPL or the LGPL, and not to allow others to
# use your version of this file under the terms of the MPL, indicate your
# decision by deleting the provisions above and replace them with the notice
# and other provisions required by the GPL or the LGPL. If you do not delete
# the provisions above, a recipient may use your version of this file under
# the terms of any one of the MPL, the GPL or the LGPL.
#
# ***** END LICENSE BLOCK *****
// A simple class that encapsulates a request. You'll notice the
// style here is different from the rest of the extension; that's
// because this was re-used from really old code we had. At some
// point it might be nice to replace this with something better
// (e.g., something that has explicit onerror handler, ability
// to set headers, and so on).
//
// The only interesting thing here is its ability to strip cookies
// from the request.
/**
* Because we might be in a component, we can't just assume that
* XMLHttpRequest exists. So we use this tiny factory function to wrap the
* XPCOM version.
*
* @return XMLHttpRequest object
*/
function PROT_NewXMLHttpRequest() {
var Cc = Components.classes;
var Ci = Components.interfaces;
var request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
.createInstance(Ci.nsIXMLHttpRequest);
// Need the following so we get onerror/load/progresschange
request.QueryInterface(Ci.nsIJSXMLHttpRequest);
return request;
}
/**
* A helper class that does HTTP GETs and calls back a function with
* the content it receives. Asynchronous, so uses a closure for the
* callback.
*
* @param opt_stripCookies Boolean indicating whether we should strip
* cookies from this request
*
* @constructor
*/
function PROT_XMLFetcher(opt_stripCookies) {
this.debugZone = "xmlfetcher";
this._request = PROT_NewXMLHttpRequest();
this._stripCookies = !!opt_stripCookies;
}
PROT_XMLFetcher.prototype = {
/**
* Function that will be called back upon fetch completion.
*/
_callback: null,
/**
* Fetches some content.
*
* @param page URL to fetch
* @param callback Function to call back when complete.
*/
get: function(page, callback) {
this._request.abort(); // abort() is asynchronous, so
this._request = PROT_NewXMLHttpRequest();
this._callback = callback;
var asynchronous = true;
this._request.open("GET", page, asynchronous);
this._request.channel.notificationCallbacks = this;
if (this._stripCookies)
new PROT_CookieStripper(this._request.channel);
// Create a closure
var self = this;
this._request.addEventListener("readystatechange", function() {
self.readyStateChange(self);
}, false);
this._request.send(null);
},
cancel: function() {
this._request.abort();
this._request = null;
},
/**
* Called periodically by the request to indicate some state change. 4
* means content has been received.
*/
readyStateChange: function(fetcher) {
if (fetcher._request.readyState != 4)
return;
// If the request fails, on trunk we get status set to
// NS_ERROR_NOT_AVAILABLE. On 1.8.1 branch we get an exception
// forwarded from nsIHttpChannel::GetResponseStatus. To be consistent
// between branch and trunk, we send back NS_ERROR_NOT_AVAILABLE for
// http failures.
var responseText = null;
var status = Components.results.NS_ERROR_NOT_AVAILABLE;
try {
G_Debug(this, "xml fetch status code: \"" +
fetcher._request.status + "\"");
status = fetcher._request.status;
responseText = fetcher._request.responseText;
} catch(e) {
G_Debug(this, "Caught exception trying to read xmlhttprequest " +
"status/response.");
G_Debug(this, e);
}
if (fetcher._callback)
fetcher._callback(responseText, status);
},
// Suppress any certificate errors
notifyCertProblem: function(socketInfo, status, targetSite) {
return true;
},
// Suppress any ssl errors
notifySSLError: function(socketInfo, error, targetSite) {
return true;
},
// nsIInterfaceRequestor
getInterface: function(iid) {
return this.QueryInterface(iid);
},
QueryInterface: function(iid) {
if (!iid.equals(Components.interfaces.nsIBadCertListener2) &&
!iid.equals(Components.interfaces.nsISSLErrorListener) &&
!iid.equals(Components.interfaces.nsIInterfaceRequestor) &&
!iid.equals(Components.interfaces.nsISupports))
throw Components.results.NS_ERROR_NO_INTERFACE;
return this;
}
};
/**
* This class knows how to strip cookies from an HTTP request. It
* listens for http-on-modify-request, and modifies the request
* accordingly. We can't do this using xmlhttprequest.setHeader() or
* nsIChannel.setRequestHeader() before send()ing because the cookie
* service is called after send().
*
* @param channel nsIChannel in which the request is happening
* @constructor
*/
function PROT_CookieStripper(channel) {
this.debugZone = "cookiestripper";
this.topic_ = "http-on-modify-request";
this.channel_ = channel;
var Cc = Components.classes;
var Ci = Components.interfaces;
this.observerService_ = Cc["@mozilla.org/observer-service;1"]
.getService(Ci.nsIObserverService);
this.observerService_.addObserver(this, this.topic_, false);
// If the request doesn't issue, don't hang around forever
var twentySeconds = 20 * 1000;
this.alarm_ = new G_Alarm(BindToObject(this.stopObserving, this),
twentySeconds);
}
/**
* Invoked by the observerservice. See nsIObserve.
*/
PROT_CookieStripper.prototype.observe = function(subject, topic, data) {
if (topic != this.topic_ || subject != this.channel_)
return;
G_Debug(this, "Stripping cookies for channel.");
this.channel_.QueryInterface(Components.interfaces.nsIHttpChannel);
this.channel_.setRequestHeader("Cookie", "", false /* replace, not add */);
this.alarm_.cancel();
this.stopObserving();
}
/**
* Remove us from the observerservice
*/
PROT_CookieStripper.prototype.stopObserving = function() {
G_Debug(this, "Removing observer");
this.observerService_.removeObserver(this, this.topic_);
this.channel_ = this.alarm_ = this.observerService_ = null;
}
/**
* XPCOM cruft
*/
PROT_CookieStripper.prototype.QueryInterface = function(iid) {
var Ci = Components.interfaces;
if (iid.equals(Ci.nsISupports) || iid.equals(Ci.nsIObserve))
return this;
throw Components.results.NS_ERROR_NO_INTERFACE;
}