Issue 6622 - Implement $rewrite filter option

lib/requestBlocker.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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
@@ skipping 52 matching lines @@
   if (!(browser.webRequest.ResourceType))
     return;
 
   for (let type in browser.webRequest.ResourceType)
     yield resourceTypes.get(browser.webRequest.ResourceType[type]) || "OTHER";
 
   // WEBRTC gets addressed through a workaround, even if the webRequest API is
   // lacking support to block this kind of a request.
   yield "WEBRTC";
 
-  // These filter types aren't mapped to resource types.
+  // POPUP, CSP and ELEMHIDE filters aren't mapped to resource types.
   yield "POPUP";
   yield "ELEMHIDE";
   yield "CSP";
 }());
 
 function getDocumentInfo(page, frame, originUrl)
 {
   return [
     extractHostFromFrame(frame, originUrl),
     getKey(page, frame, originUrl),
@@ skipping 17 matching lines @@
   // If tabId is -1, its not (e.g. the request was sent by
   // a Service/Shared Worker) and we have to identify the related tabs.
   if (details.tabId != -1)
     return Promise.resolve([details.tabId]);
 
   let url;                    // Firefox provides "originUrl" indicating the
   if (details.originUrl)      // URL of the tab that caused this request.
     url = details.originUrl;  // In case of Service/Shared Worker, this is the
                               // URL of the tab that caused the worker to spawn.
 
-  else if (details.initiator)        // Chromium >=63 provides "intiator" which
-    url = details.initiator + "/*";  // is equivalent to "originUrl" on Firefox
+  else if (details.initiator && details.initiator != "null")
+    url = details.initiator + "/*";  // Chromium >=63 provides "intiator" which
+                                     // is equivalent to "originUrl" on Firefox
                                      // except that its not a full URL but just
                                      // an origin (proto + host).
   else
     return Promise.resolve([]);
 
   return browser.tabs.query({url}).then(tabs => tabs.map(tab => tab.id));
 }
 
 function logRequest(tabIds, request, filter)
 {
@@ skipping 15 matching lines @@
   // listener. But unfortunately, Chrome <=57 doesn't support the WebSocket
   // protocol and is causing an error if it is given.
   let url = new URL(details.url);
   if (url.protocol != "http:" && url.protocol != "https:" &&
       url.protocol != "ws:" && url.protocol != "wss:")
     return;
 
   // Firefox provides us with the full origin URL, while Chromium (>=63)
   // provides only the protocol + host of the (top-level) document which
   // the request originates from through the "initiator" property.
-  let originUrl = details.originUrl ? new URL(details.originUrl) :
-                  details.initiator ? new URL(details.initiator) : null;
+  let originUrl = null;
+  if (details.originUrl)
+    originUrl = new URL(details.originUrl);
+  else if (details.initiator && details.initiator != "null")
+    originUrl = new URL(details.initiator);
 
   // Ignore requests sent by extensions or by Firefox itself:
   // * Firefox intercepts requests sent by any extensions, indicated with
   //   an "originURL" starting with "moz-extension:".
   // * Chromium intercepts requests sent by this extension only, indicated
   //   on Chromium >=63 with an "initiator" starting with "chrome-extension:".
   // * On Firefox, requests that don't relate to any document or extension are
   //   indicated with an "originUrl" starting with "chrome:".
   if (originUrl && (originUrl.protocol == extensionProtocol ||
                     originUrl.protocol == "chrome:"))
     return;
 
   let page = new ext.Page({id: details.tabId});
   let frame = ext.getFrame(
     details.tabId,
     // We are looking for the frame that contains the element which
     // has triggered this request. For most requests (e.g. images) we
     // can just use the request's frame ID, but for subdocument requests
     // (e.g. iframes) we must instead use the request's parent frame ID.
     details.type == "sub_frame" ? details.parentFrameId : details.frameId
   );
 
   // On Chromium >= 63, if both the frame is unknown and we haven't get
-  // an "initator", this implies a request sent by the browser itself
-  // (on older versions of Chromium, due to the lack of "initator",
+  // an "initiator", this implies a request sent by the browser itself
+  // (on older versions of Chromium, due to the lack of "initiator",
   // this can also indicate a request sent by a Shared/Service Worker).
   if (!frame && !originUrl)
     return;
 
   if (checkWhitelisted(page, frame, originUrl))
     return;
 
   let type = resourceTypes.get(details.type) || "OTHER";
   let [docDomain, sitekey, specificOnly] = getDocumentInfo(page, frame,
                                                            originUrl);
   let [filter, thirdParty] = matchRequest(url, type, docDomain,
                                           sitekey, specificOnly);
 
   let result;
-  let rewrittenTo;
+  let rewrittenUrl;
 
   if (filter instanceof BlockingFilter)
   {
     if (filter.rewrite)
     {
-      rewrittenTo = filter.rewriteUrl(details.url);
-      // If no rewrite happened (error, diff origin), we'll

[Manish Jethani, 2018/05/11 14:11:19]

Nit: can we spell out "different" here? :) (Sorry about being a stickler)

[hub, 2018/05/11 15:58:25]

Done.

+      rewrittenUrl = filter.rewriteUrl(details.url);
+      // If no rewrite happened (error, different origin), we'll
       // return undefined in order to avoid an "infinite" loop.
-      if (rewrittenTo != details.url)
-        result = {redirectUrl: rewrittenTo};
+      if (rewrittenUrl != details.url)
+        result = {redirectUrl: rewrittenUrl};
     }
     else
       result = {cancel: true};
   }
 
   getRelatedTabIds(details).then(tabIds =>
   {
     logRequest(
       tabIds,
       {
         url: details.url, type, docDomain, thirdParty,
-        sitekey, specificOnly, rewrittenTo
+        sitekey, specificOnly, rewrittenUrl
       },
       filter
     );
   });
 
   return result;
 }, {urls: ["<all_urls>"]}, ["blocking"]);
 
 port.on("filters.collapse", (message, sender) =>
 {
@@ skipping 102 matching lines @@
 }
 
 FilterNotifier.on("subscription.added", onFilterChange);
 FilterNotifier.on("subscription.removed", onFilterChange);
 FilterNotifier.on("subscription.updated", onFilterChange);
 FilterNotifier.on("subscription.disabled", arg => onFilterChange(arg, true));
 FilterNotifier.on("filter.added", onFilterChange);
 FilterNotifier.on("filter.removed", onFilterChange);
 FilterNotifier.on("filter.disabled", arg => onFilterChange(arg, true));
 FilterNotifier.on("load", onFilterChange);