Bug 1212904 P1 Add a LoadTainting enumeration. r=jduell

netwerk/base/LoadTainting.h

@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_LoadTainting_h
+#define mozilla_LoadTainting_h
+
+namespace mozilla {
+
+// Define an enumeration to reflect the concept of response tainting from the
+// the fetch spec:
+//
+//  https://fetch.spec.whatwg.org/#concept-request-response-tainting
+//
+// Roughly the tainting means:
+//
+//  * Basic: the request resulted in a same-origin or non-http load
+//  * CORS: the request resulted in a cross-origin load with CORS headers
+//  * Opaque: the request resulted in a cross-origin load without CORS headers
+//
+// The enumeration is purposefully designed such that more restrictive tainting
+// corresponds to a higher integral value.
+//
+// NOTE: Checking the tainting is not currently adequate.  You *must* still
+//       check the final URL and CORS mode on the channel.
+//
+// These values are currently only set on the channel LoadInfo when the request
+// was initiated through fetch() or when a service worker interception occurs.
+// In the future we should set the tainting value within necko so that it is
+// consistently applied.  Once that is done consumers can replace checks against
+// the final URL and CORS mode with checks against tainting.
+enum class LoadTainting : uint8_t
+{
+  Basic = 0,
+  CORS = 1,
+  Opaque = 2
+};
+
+} // namespace mozilla
+
+#endif // mozilla_LoadTainting_h

netwerk/base/moz.build

@@ -168,6 +168,7 @@ EXPORTS += [
 
 EXPORTS.mozilla += [
     'LoadInfo.h',
+    'LoadTainting.h',
 ]
 
 EXPORTS.mozilla.net += [