Issue 7232 - Move third-party request check into adblockpluscore

lib/domain.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
  * 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/>.
  */
 
 "use strict";
 
 const publicSuffixes = require("../data/publicSuffixList.json");
 
 /**
+ * Checks whether the given hostname is a domain.
+ *
+ * @param {string} hostname
+ * @returns {boolean}
+ */
+function isDomain(hostname)
+{
+  // No hostname or IPv4 address, also considering hexadecimal octets.
+  if (/^((0x[\da-f]+|\d+)(\.|$))*$/i.test(hostname))
+    return false;
+
+  // IPv6 address. Since there can't be colons in domains, we can
+  // just check whether there are any colons to exclude IPv6 addresses.
+  return hostname.indexOf(":") == -1;
+}
+
+/**
  * Gets the base domain for the given hostname.
  *
  * @param {string} hostname
  * @returns {string}
  */
-exports.getDomain = hostname =>
+function getDomain(hostname)
 {
   let bits = hostname.split(".");
   let cutoff = bits.length - 2;
 
   for (let i = 0; i < bits.length; i++)
   {
     let offset = publicSuffixes[bits.slice(i).join(".")];
 
     if (typeof offset != "undefined")
     {
       cutoff = i - offset;
       break;
     }
   }
 
   if (cutoff <= 0)
     return hostname;
 
   return bits.slice(cutoff).join(".");
-};
+}
+
+/**
+ * Checks whether a request's origin is different from its document's origin.
+ *
+ * @param {URL} url The request URL.
+ * @param {string} documentHostname The IDNA-encoded hostname of the document.

[Manish Jethani, 2019/01/23 03:25:25]

Renamed to documentHostname for clarity (this must not include the port number).

Also, the name needs to be encoded, not decoded, because the hostname property
of the URL object is encoded.

+ *
+ * @returns {boolean}
+ */
+function isThirdParty(url, documentHostname)
+{
+  let requestHostname = url.hostname.replace(/\.+$/, "");
+  documentHostname = documentHostname.replace(/\.+$/, "");
+
+  if (requestHostname == documentHostname)
+    return false;
+
+  if (!isDomain(requestHostname) || !isDomain(documentHostname))
+    return true;
+
+  return getDomain(requestHostname) != getDomain(documentHostname);
+}
+
+exports.isThirdParty = isThirdParty;