Issue 3108 - Inject our about: module into all processes

lib/elemHide.js

Index: lib/elemHide.js
===================================================================
--- a/lib/elemHide.js
+++ b/lib/elemHide.js
@@ -21,17 +21,16 @@
 
 Cu.import("resource://gre/modules/Services.jsm");
 
 let {Utils} = require("utils");
 let {IO} = require("io");
 let {Prefs} = require("prefs");
 let {ElemHideException} = require("filterClasses");
 let {FilterNotifier} = require("filterNotifier");
-let {AboutHandler} = require("elemHideHitRegistration");
 
 /**
  * Lookup table, filters by their associated key
  * @type Object
  */
 let filterByKey = Object.create(null);
 
 /**
@@ -76,25 +75,32 @@ let ElemHide = exports.ElemHide =
    */
   applied: false,
 
   /**
    * Called on module startup.
    */
   init: function()
   {
+    let messageManager = Cc["@mozilla.org/parentprocessmessagemanager;1"]
+                           .getService(Ci.nsIMessageListenerManager);
+    let hitHandler = (message => {
+      let result = ElemHide.shouldHide(message.data);
+      let target = message.target.QueryInterface(Ci.nsIMessageSender);
+      target.sendAsyncMessage(message.data.responseMessage, result);
+    });
+    messageManager.addMessageListener("AdblockPlus:ElemHideHit", hitHandler);
+    onShutdown.add(() => messageManager.removeMessageListener("AdblockPlus:ElemHideHit", hitHandler));
+
     Prefs.addListener(function(name)
     {
       if (name == "enabled")
         ElemHide.apply();
     });
-    onShutdown.add(function()
-    {
-      ElemHide.unapply();
-    });
+    onShutdown.add(() => ElemHide.unapply());
 
     let styleFile = IO.resolveFilePath(Prefs.data_directory);
     styleFile.append("elemhide.css");
     styleURL = Services.io.newFileURI(styleFile).QueryInterface(Ci.nsIFileURL);
   },
 
   /**
    * Removes all known filters
@@ -184,16 +190,64 @@ let ElemHide = exports.ElemHide =
     for (let i = list.length - 1; i >= 0; i--)
       if (list[i].isActiveOnDomain(docDomain))
         return list[i];
 
     return null;
   },
 
   /**
+   * Processes an element hiding hit
+   * @param {String} message.key
+   *    key of the matching element hiding rule
+   * @param {Object[]} message.frames
+   *    information required to reconstruct frame
+   *    data for the hit
+   * @return {Boolean}
+   */
+  shouldHide: function(message)
+  {
+    let filter = ElemHide.getFilterByKey(message.key);
+    if (!filter || !message.frames.length)
+      return false;
+
+    let fakeFrame = null;
+    for (let i = message.frames.length - 1; i >= 0; i--)
+    {
+      fakeFrame = {
+        parent: fakeFrame,
+        location: {
+          href: message.frames[i].location
+        },
+        document: {
+          documentElement: {}
+        },
+        QueryInterface: function() {return this;},
+        getInterface: function() {return this;},
+        usePrivateBrowsing: (fakeFrame ? fakeFrame.usePrivateBrowsing : message.frames[i].privateBrowsing)
+      };
+      fakeFrame.top = fakeFrame.parent || fakeFrame;
+      if (!fakeFrame.parent)
+        fakeFrame.parent = fakeFrame;
+
+      let sitekey = message.frames[i].sitekey || null;
+      fakeFrame.document.documentElement.getAttribute = function(attr)
+      {
+        if (attr == "data-adblockkey")
+          return sitekey;
+        else
+          return null;
+      };
+    }
+
+    let {Policy} = require("contentPolicy");
+    return !Policy.processNode(fakeFrame, fakeFrame.document, Policy.type.ELEMHIDE, filter);

[Wladimir Palant, 2015/10/16 12:15:10]

Side-effect here: the hit info is attached to a fake window, meaning that it
won't appear in the blockable items list. Not really feasible to fix until we
start injecting the content policy into all processes as well (at this point we
will also be able to stop faking DOM structures here).

+  },
+
+  /**
    * Will be set to true if apply() is running (reentrance protection).
    * @type Boolean
    */
   _applying: false,
 
   /**
    * Will be set to true if an apply() call arrives while apply() is already
    * running (delayed execution).
@@ -308,17 +362,17 @@ let ElemHide = exports.ElemHide =
       throw Cr.NS_ERROR_NOT_AVAILABLE;
 
     function escapeChar(match)
     {
       return "\\" + match.charCodeAt(0).toString(16) + " ";
     }
 
     // Return CSS data
-    let cssTemplate = "-moz-binding: url(about:" + AboutHandler.aboutPrefix + "?%ID%#dummy) !important;";
+    let cssTemplate = "-moz-binding: url(about:abp-elemhidehit?%ID%#dummy) !important;";
     for (let domain in domains)
     {
       let rules = [];
       let list = domains[domain];
 
       if (domain)
         yield ('@-moz-document domain("' + domain.split(",").join('"),domain("') + '"){').replace(/[^\x01-\x7F]/g, escapeChar);
       else