Issue 3208 - Separate contentPolicy module into a parent and child part

lib/child/contentPolicy.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /**
  * @fileOverview Content policy implementation, responsible for blocking things.
  */
 
 "use strict";
 
+try
+{
+  // Hack: SDK loader masks our Components object with a getter.
+  let proto = Object.getPrototypeOf(this);
+  let property = Object.getOwnPropertyDescriptor(proto, "Components");
+  if (property && property.get)
+    delete proto.Components;
+}
+catch (e)
+{
+  Cu.reportError(e);
+}
+
 let {XPCOMUtils} = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
 let {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
-let {PrivateBrowsingUtils} = Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm", {});
 
 let {Utils} = require("utils");
-let {Prefs} = require("prefs");
-let {FilterStorage} = require("filterStorage");
-let {BlockingFilter, WhitelistFilter, RegExpFilter} = require("filterClasses");
-let {defaultMatcher} = require("matcher");
+let {getFrames, isPrivate} = require("child/utils");
 let {objectMouseEventHander} = require("objectTabs");
 let {RequestNotifier} = require("requestNotifier");
-let {ElemHide} = require("elemHide");
 
 /**
  * Randomly generated class name, to be applied to collapsed nodes.
  */
-let collapsedClass = "";
+let collapsedClass = null;
 
 /**
  * Maps numerical content type IDs to strings.
  * @type Map
  */
 let types = new Map();
 
 /**
- * Public policy checking functions and auxiliary objects
- * @class
+ * Checks whether a request should be allowed, hides it if necessary
+ * @param wnd {nsIDOMWindow}
+ * @param node {nsIDOMElement}
+ * @param contentType {String}
+ * @param location {String}
+ * @return {Boolean} false if the request should be blocked
  */
-var Policy = exports.Policy =
+function shouldAllow(window, node, contentType, location)
 {
-  /**
-   * Set of explicitly supported content types
-   * @type Set
-   */
-  contentTypes: new Set([
-    "OTHER", "SCRIPT", "IMAGE", "STYLESHEET", "OBJECT", "SUBDOCUMENT", "DOCUMENT",
-    "XMLHTTPREQUEST", "OBJECT_SUBREQUEST", "FONT", "MEDIA", "ELEMHIDE", "POPUP",
-    "GENERICHIDE", "GENERICBLOCK"
-  ]),
+  let response = sendSyncMessage("AdblockPlus:ShouldAllow", {
+    contentType: contentType,
+    location: location,
+    frames: getFrames(window),
+    isPrivate: isPrivate(window)
+  });
+  if (response.length == 0)
+    return true;
 
-  /**
-   * Set of content types that aren't associated with a visual document area
-   * @type Set
-   */
-  nonVisualTypes: new Set([
-    "SCRIPT", "STYLESHEET", "XMLHTTPREQUEST", "OBJECT_SUBREQUEST", "FONT",
-    "ELEMHIDE", "POPUP", "GENERICHIDE", "GENERICBLOCK"
-  ]),
+  let {allow, collapse, hits} = response[0];
+  for (let {frameIndex, contentType, docDomain, thirdParty, location, filter} of hits)
+  {
+    let context = node;
+    if (typeof frameIndex == "number")
+    {
+      context = window;
+      for (let i = 0; i < frameIndex; i++)
+        context = context.parent;
+      context = context.document;
+    }
+    RequestNotifier.addNodeData(context, window.top, contentType, docDomain, thirdParty, location, filter);
+  }
 
-  /**
-   * Map containing all schemes that should be ignored by content policy.
-   * @type Set
-   */
-  whitelistSchemes: new Set(),
-
-  /**
-   * Called on module startup, initializes various exported properties.
-   */
-  init: function()
+  if (node.nodeType == Ci.nsIDOMNode.ELEMENT_NODE)
   {
-    // whitelisted URL schemes
-    for (let scheme of Prefs.whitelistschemes.toLowerCase().split(" "))
-      this.whitelistSchemes.add(scheme);
-
-    // Generate class identifier used to collapse node and register corresponding
-    // stylesheet.
-    let offset = "a".charCodeAt(0);
-    for (let i = 0; i < 20; i++)
-      collapsedClass +=  String.fromCharCode(offset + Math.random() * 26);
-
-    let collapseStyle = Services.io.newURI("data:text/css," +
-        encodeURIComponent("." + collapsedClass +
-        "{-moz-binding: url(chrome://global/content/bindings/general.xml#foobarbazdummy) !important;}"), null, null);
-    Utils.styleService.loadAndRegisterSheet(collapseStyle, Ci.nsIStyleSheetService.USER_SHEET);
-    onShutdown.add(() =>
+    // Track mouse events for objects
+    if (allow && contentType == "OBJECT")
     {
-      Utils.styleService.unregisterSheet(collapseStyle, Ci.nsIStyleSheetService.USER_SHEET);
-    });
-  },
-
-  /**
-   * Checks whether a node should be blocked, hides it if necessary
-   * @param wnd {nsIDOMWindow}
-   * @param node {nsIDOMElement}
-   * @param contentType {String}
-   * @param location {String}
-   * @param collapse {Boolean} true to force hiding of the node
-   * @return {Boolean} false if the node should be blocked
-   */
-  processNode: function(wnd, node, contentType, location, collapse)
-  {
-    let topWnd = wnd.top;
-    if (!topWnd || !topWnd.location || !topWnd.location.href)
-      return true;
-
-    // Ignore whitelisted schemes
-    if (!this.isBlockableScheme(location))
-      return true;
-
-    // Interpret unknown types as "other"
-    if (!this.contentTypes.has(contentType))
-      contentType = "OTHER";
-
-    let originWindow = Utils.getOriginWindow(wnd);
-    let wndLocation = originWindow.location.href;
-    let docDomain = getHostname(wndLocation);
-    let match = null;
-    let [sitekey, sitekeyWnd] = getSitekey(wnd);
-    let nogeneric = false;
-
-    function cleanWindowLocation(wnd)
-    {
-      let url = getWindowLocation(wnd);
-      let index = url.indexOf("#");
-      if (index >= 0)
-        url = url.substring(0, index);
-
-      return url;
+      node.addEventListener("mouseover", objectMouseEventHander, true);
+      node.addEventListener("mouseout", objectMouseEventHander, true);
     }
 
-    function addHit(match)
-    {
-      if (!PrivateBrowsingUtils.isContentWindowPrivate(wnd))
-        FilterStorage.increaseHitCount(match);
-    }
+    if (collapse)
+      schedulePostProcess(node);
+  }
 
-    if (!match && Prefs.enabled)
-    {
-      let testWnd = wnd;
-      let testSitekey = sitekey;
-      let testSitekeyWnd = sitekeyWnd;
-      let parentWndLocation = cleanWindowLocation(testWnd);
-      while (true)
-      {
-        let testWndLocation = parentWndLocation;
-        parentWndLocation = (testWnd == testWnd.parent ? testWndLocation : cleanWindowLocation(testWnd.parent));
-        let parentDocDomain = getHostname(parentWndLocation);
-
-        let typeMap = RegExpFilter.typeMap.DOCUMENT;
-        if (contentType == "ELEMHIDE")
-          typeMap = typeMap | RegExpFilter.typeMap.ELEMHIDE;
-        let whitelistMatch = defaultMatcher.matchesAny(testWndLocation, typeMap, parentDocDomain, false, sitekey);
-        if (whitelistMatch instanceof WhitelistFilter)
-        {
-          addHit(whitelistMatch);
-          RequestNotifier.addNodeData(testWnd.document, topWnd,
-            (whitelistMatch.contentType & RegExpFilter.typeMap.DOCUMENT) ? "DOCUMENT" : "ELEMHIDE",
-            parentDocDomain, false, testWndLocation, whitelistMatch);
-          return true;
-        }
-
-        let genericType = (contentType == "ELEMHIDE" ? "GENERICHIDE" : "GENERICBLOCK");
-        let nogenericMatch = defaultMatcher.matchesAny(testWndLocation,
-            RegExpFilter.typeMap[genericType], parentDocDomain, false, testSitekey);
-        if (nogenericMatch instanceof WhitelistFilter)
-        {
-          nogeneric = true;
-
-          addHit(nogenericMatch);
-          RequestNotifier.addNodeData(testWnd.document, topWnd, genericType,
-                                      parentDocDomain, false, testWndLocation,
-                                      nogenericMatch);
-        }
-
-        if (testWnd.parent == testWnd)
-          break;
-
-        if (testWnd == testSitekeyWnd)
-          [testSitekey, testSitekeyWnd] = getSitekey(testWnd.parent);
-        testWnd = testWnd.parent;
-      }
-    }
-
-    if (!match && contentType == "ELEMHIDE")
-    {
-      match = location;
-      location = match.text.replace(/^.*?#/, '#');
-
-      if (!match.isActiveOnDomain(docDomain))
-        return true;
-
-      let exception = ElemHide.getException(match, docDomain);
-      if (exception)
-      {
-        addHit(exception);
-        RequestNotifier.addNodeData(node, topWnd, contentType, docDomain, false, location, exception);
-        return true;
-      }
-
-      if (nogeneric && match.isGeneric())
-        return true;
-    }
-
-    let thirdParty = (contentType == "ELEMHIDE" ? false : isThirdParty(location, docDomain));
-
-    if (!match && Prefs.enabled && RegExpFilter.typeMap.hasOwnProperty(contentType))
-    {
-      match = defaultMatcher.matchesAny(location, RegExpFilter.typeMap[contentType],
-                                        docDomain, thirdParty, sitekey, nogeneric);
-      if (match instanceof BlockingFilter && node.ownerDocument && !this.nonVisualTypes.has(contentType))
-      {
-        let prefCollapse = (match.collapse != null ? match.collapse : !Prefs.fastcollapse);
-        if (collapse || prefCollapse)
-          schedulePostProcess(node);
-      }
-
-      // Track mouse events for objects
-      if (!match && contentType == "OBJECT" && node.nodeType == Ci.nsIDOMNode.ELEMENT_NODE)
-      {
-        node.addEventListener("mouseover", objectMouseEventHander, true);
-        node.addEventListener("mouseout", objectMouseEventHander, true);
-      }
-    }
-
-    // Store node data
-    RequestNotifier.addNodeData(node, topWnd, contentType, docDomain, thirdParty, location, match);
-    if (match)
-      addHit(match);
-
-    return !match || match instanceof WhitelistFilter;
-  },
-
-  /**
-   * Checks whether the location's scheme is blockable.
-   * @param location  {nsIURI|String}
-   * @return {Boolean}
-   */
-  isBlockableScheme: function(location)
-  {
-    let scheme;
-    if (typeof location == "string")
-    {
-      let match = /^([\w\-]+):/.exec(location);
-      scheme = match ? match[1] : null;
-    }
-    else
-      scheme = location.scheme;
-    return !this.whitelistSchemes.has(scheme);
-  },
-
-  /**
-   * Checks whether a page is whitelisted.
-   * @param {String} url
-   * @param {String} [parentUrl] location of the parent page
-   * @param {String} [sitekey] public key provided on the page
-   * @return {Filter} filter that matched the URL or null if not whitelisted
-   */
-  isWhitelisted: function(url, parentUrl, sitekey)
-  {
-    if (!url)
-      return null;
-
-    // Do not apply exception rules to schemes on our whitelistschemes list.
-    if (!this.isBlockableScheme(url))
-      return null;
-
-    if (!parentUrl)
-      parentUrl = url;
-
-    // Ignore fragment identifier
-    let index = url.indexOf("#");
-    if (index >= 0)
-      url = url.substring(0, index);
-
-    let result = defaultMatcher.matchesAny(url, RegExpFilter.typeMap.DOCUMENT, getHostname(parentUrl), false, sitekey);
-    return (result instanceof WhitelistFilter ? result : null);
-  },
-
-  /**
-   * Checks whether the page loaded in a window is whitelisted for indication in the UI.
-   * @param wnd {nsIDOMWindow}
-   * @return {Filter} matching exception rule or null if not whitelisted
-   */
-  isWindowWhitelisted: function(wnd)
-  {
-    return this.isWhitelisted(getWindowLocation(wnd));
-  },
-
-  /**
-   * Asynchronously re-checks filters for given nodes.
-   * @param {Node[]} nodes
-   * @param {RequestEntry} entry
-   */
-  refilterNodes: function(nodes, entry)
-  {
-    // Ignore nodes that have been blocked already
-    if (entry.filter && !(entry.filter instanceof WhitelistFilter))
-      return;
-
-    for (let node of nodes)
-      Utils.runAsync(() => refilterNode(node, entry));
-  }
-};
-Policy.init();
+  return allow;
+}
 
 /**
  * Actual nsIContentPolicy and nsIChannelEventSink implementation
  * @class
  */
 var PolicyImplementation =
 {
   classDescription: "Adblock Plus content policy",
   classID: Components.ID("cfeaabe6-1dd1-11b2-a0c6-cb5c268894c9"),
   contractID: "@adblockplus.org/abp/policy;1",
   xpcom_categories: ["content-policy", "net-channel-event-sinks"],
 
   /**
    * Registers the content policy on startup.
    */
   init: function()
   {
     // Populate types map
     let iface = Ci.nsIContentPolicy;
     for (let name in iface)
       if (name.indexOf("TYPE_") == 0 && name != "TYPE_DATAREQUEST")
         types.set(iface[name], name.substr(5));
 
     let registrar = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
     registrar.registerFactory(this.classID, this.classDescription, this.contractID, this);
 
     let catMan = Utils.categoryManager;
+    let addCategoryEntry = Utils.getPropertyWithoutCompatShims(catMan, "addCategoryEntry");
     for (let category of this.xpcom_categories)
-      catMan.addCategoryEntry(category, this.contractID, this.contractID, false, true);
+      addCategoryEntry.call(catMan, category, this.contractID, this.contractID, false, true);
 
-    Services.obs.addObserver(this, "content-document-global-created", true);
+    let addObserver = Utils.getPropertyWithoutCompatShims(Services.obs, "addObserver");
+    addObserver.call(Services.obs, this, "content-document-global-created", true);
 
     onShutdown.add(() =>
     {
-      Services.obs.removeObserver(this, "content-document-global-created");
+      let removeObserver = Utils.getPropertyWithoutCompatShims(Services.obs, "removeObserver");
+      removeObserver.call(Services.obs, this, "content-document-global-created");
 
       for (let category of this.xpcom_categories)
         catMan.deleteCategoryEntry(category, this.contractID, false);
 
       registrar.unregisterFactory(this.classID, this);
     });
   },
 
   //
   // nsISupports interface implementation
@@ skipping 22 matching lines @@
 
     // Data loaded by plugins should be associated with the document
     if (contentType == Ci.nsIContentPolicy.TYPE_OBJECT_SUBREQUEST && node instanceof Ci.nsIDOMElement)
       node = node.ownerDocument;
 
     // Fix type for objects misrepresented as frames or images
     if (contentType != Ci.nsIContentPolicy.TYPE_OBJECT && (node instanceof Ci.nsIDOMHTMLObjectElement || node instanceof Ci.nsIDOMHTMLEmbedElement))
       contentType = Ci.nsIContentPolicy.TYPE_OBJECT;
 
     let location = Utils.unwrapURL(contentLocation);
-    let result = Policy.processNode(wnd, node, types.get(contentType), location.spec, false);
+    let result = shouldAllow(wnd, node, types.get(contentType), location.spec);
     return (result ? Ci.nsIContentPolicy.ACCEPT : Ci.nsIContentPolicy.REJECT_REQUEST);
   },
 
   shouldProcess: function(contentType, contentLocation, requestOrigin, insecNode, mimeType, extra)
   {
     return Ci.nsIContentPolicy.ACCEPT;
   },
 
   //
   // nsIObserver interface implementation
   //
   observe: function(subject, topic, data, additional)
   {
     switch (topic)
     {
       case "content-document-global-created":
       {
         if (!(subject instanceof Ci.nsIDOMWindow) || !subject.opener)
           return;
 
         let uri = additional || subject.location.href;
-        if (!Policy.processNode(subject.opener, subject.opener.document, "POPUP", uri, false))
+        if (!shouldAllow(subject.opener, subject.opener.document, "POPUP", uri))
         {
           subject.stop();
           Utils.runAsync(() => subject.close());
         }
         else if (uri == "about:blank")
         {
           // An about:blank pop-up most likely means that a load will be
           // initiated asynchronously. Wait for that.
           Utils.runAsync(() =>
           {
@@ skipping 38 matching lines @@
           // Special treatment for pop-up windows - this will close the window
           // rather than preventing the redirect. Note that we might not have
           // seen the original channel yet because the redirect happened before
           // the async code in observe() had a chance to run.
           this.observe(wnd, "content-document-global-created", null, oldChannel.URI.spec);
           this.observe(wnd, "content-document-global-created", null, newChannel.URI.spec);
         }
         return;
       }
 
-      if (!Policy.processNode(wnd, wnd.document, types.get(contentType), newChannel.URI.spec, false))
+      if (!shouldAllow(wnd, wnd.document, types.get(contentType), newChannel.URI.spec))
         result = Cr.NS_BINDING_ABORTED;
     }
     catch (e)
     {
       // We shouldn't throw exceptions here - this will prevent the redirect.
       Cu.reportError(e);
     }
     finally
     {
       callback.onRedirectVerifyCallback(result);
@@ skipping 31 matching lines @@
     scheduledNodes = [node];
     Utils.runAsync(postProcessNodes);
   }
 }
 
 /**
  * Processes nodes scheduled for post-processing (typically hides them).
  */
 function postProcessNodes()
 {
+  if (!collapsedClass)
+  {
+    let response = sendSyncMessage("AdblockPlus:GetCollapsedClass");
+    if (response.length)
+      collapsedClass = response[0];
+
+    if (!collapsedClass)
+    {
+      Utils.runAsync(postProcessNodes);

[Thomas Greiner, 2015/11/11 16:52:33]

I'd suggest either stopping this loop at some point or introducing an
exponentially increasing timeout so that in case we're - for whatever reason -
not getting a collapsed class back that it wouldn't lead to an infinite loop but
instead only to elements not getting collapsed.

[Wladimir Palant, 2015/11/11 17:43:25]

Actually, that's a left-over from a previous version of this code - the parent
will set collapsedClass synchronously, so there is no scenario where retrying
makes sense.

[Thomas Greiner, 2015/11/11 18:07:32]

Ah, you're right.

+      return;
+    }
+  }
+
   let nodes = scheduledNodes;
   scheduledNodes = null;
 
   for (let node of nodes)
   {
     // adjust frameset's cols/rows for frames
     let parentNode = node.parentNode;
     if (parentNode && parentNode instanceof Ci.nsIDOMHTMLFrameSetElement)
     {
       let hasCols = (parentNode.cols && parentNode.cols.indexOf(",") > 0);
       let hasRows = (parentNode.rows && parentNode.rows.indexOf(",") > 0);
       if ((hasCols || hasRows) && !(hasCols && hasRows))
       {
         let index = -1;
         for (let frame = node; frame; frame = frame.previousSibling)
           if (frame instanceof Ci.nsIDOMHTMLFrameElement || frame instanceof Ci.nsIDOMHTMLFrameSetElement)
             index++;
 
         let property = (hasCols ? "cols" : "rows");
         let weights = parentNode[property].split(",");
         weights[index] = "0";
         parentNode[property] = weights.join(",");
       }
     }
     else
       node.classList.add(collapsedClass);
   }
 }
-
-/**
- * Extracts the hostname from a URL (might return null).
- */
-function getHostname(/**String*/ url) /**String*/
-{
-  try
-  {
-    return Utils.unwrapURL(url).host;
-  }
-  catch(e)
-  {
-    return null;
-  }
-}
-
-/**
- * Retrieves the sitekey of a window.
- */
-function getSitekey(wnd)
-{
-  let sitekey = null;
-
-  while (true)
-  {
-    if (wnd.document && wnd.document.documentElement)
-    {
-      let keydata = wnd.document.documentElement.getAttribute("data-adblockkey");
-      if (keydata && keydata.indexOf("_") >= 0)
-      {
-        let [key, signature] = keydata.split("_", 2);
-        key = key.replace(/=/g, "");
-
-        // Website specifies a key but is the signature valid?
-        let uri = Services.io.newURI(getWindowLocation(wnd), null, null);
-        let host = uri.asciiHost;
-        if (uri.port > 0)
-          host += ":" + uri.port;
-        let params = [
-          uri.path.replace(/#.*/, ""),  // REQUEST_URI
-          host,                         // HTTP_HOST
-          Utils.httpProtocol.userAgent  // HTTP_USER_AGENT
-        ];
-        if (Utils.verifySignature(key, signature, params.join("\0")))
-          return [key, wnd];
-      }
-    }
-
-    if (wnd === wnd.parent)
-      break;
-
-    wnd = wnd.parent;
-  }
-
-  return [sitekey, wnd];
-}
-
-/**
- * Retrieves the location of a window.
- * @param wnd {nsIDOMWindow}
- * @return {String} window location or null on failure
- */
-function getWindowLocation(wnd)
-{
-  if ("name" in wnd && wnd.name == "messagepane")
-  {
-    // Thunderbird branch
-    try
-    {
-      let mailWnd = wnd.QueryInterface(Ci.nsIInterfaceRequestor)
-                       .getInterface(Ci.nsIWebNavigation)
-                       .QueryInterface(Ci.nsIDocShellTreeItem)
-                       .rootTreeItem
-                       .QueryInterface(Ci.nsIInterfaceRequestor)
-                       .getInterface(Ci.nsIDOMWindow);
-
-      // Typically we get a wrapped mail window here, need to unwrap
-      try
-      {
-        mailWnd = mailWnd.wrappedJSObject;
-      } catch(e) {}
-
-      if ("currentHeaderData" in mailWnd && "content-base" in mailWnd.currentHeaderData)
-      {
-        return mailWnd.currentHeaderData["content-base"].headerValue;
-      }
-      else if ("currentHeaderData" in mailWnd && "from" in mailWnd.currentHeaderData)
-      {
-        let emailAddress = Utils.headerParser.extractHeaderAddressMailboxes(mailWnd.currentHeaderData.from.headerValue);
-        if (emailAddress)
-          return 'mailto:' + emailAddress.replace(/^[\s"]+/, "").replace(/[\s"]+$/, "").replace(/\s/g, '%20');
-      }
-    } catch(e) {}
-  }
-
-  // Firefox branch
-  return wnd.location.href;
-}
-
-/**
- * Checks whether the location's origin is different from document's origin.
- */
-function isThirdParty(/**String*/location, /**String*/ docDomain) /**Boolean*/
-{
-  if (!location || !docDomain)
-    return true;
-
-  let uri = Utils.makeURI(location);
-  try
-  {
-    return Utils.effectiveTLD.getBaseDomain(uri) != Utils.effectiveTLD.getBaseDomainFromHost(docDomain);
-  }
-  catch (e)
-  {
-    // EffectiveTLDService throws on IP addresses, just compare the host name
-    let host = "";
-    try
-    {
-      host = uri.host;
-    } catch (e) {}
-    return host != docDomain;
-  }
-}
-
-/**
- * Re-checks filters on an element.
- */
-function refilterNode(/**Node*/ node, /**RequestEntry*/ entry)
-{
-  let wnd = Utils.getWindow(node);
-  if (!wnd || wnd.closed)
-    return;
-
-  if (entry.type == "OBJECT")
-  {
-    node.removeEventListener("mouseover", objectMouseEventHander, true);
-    node.removeEventListener("mouseout", objectMouseEventHander, true);
-  }
-  Policy.processNode(wnd, node, entry.type, entry.location, true);
-}