Bug 1522181 - multiple external protocol URL blocker behind pref, r=smaug

docshell/base/nsDocShell.cpp

@@ -9640,29 +9640,32 @@ nsresult nsDocShell::DoURILoad(nsDocShellLoadState* aLoadState,
                    aContentPolicyType == nsIContentPolicy::TYPE_INTERNAL_FRAME,
                "DoURILoad thinks this is a frame and InternalLoad does not");
 
-    // Only allow URLs able to return data in iframes.
-    bool doesNotReturnData = false;
-    NS_URIChainHasFlags(aLoadState->URI(),
-                        nsIProtocolHandler::URI_DOES_NOT_RETURN_DATA,
-                        &doesNotReturnData);
-    if (doesNotReturnData) {
-      bool popupBlocked = true;
+    if (StaticPrefs::dom_block_external_protocol_in_iframes()) {
+      // Only allow URLs able to return data in iframes.
+      bool doesNotReturnData = false;
+      NS_URIChainHasFlags(aLoadState->URI(),
+                          nsIProtocolHandler::URI_DOES_NOT_RETURN_DATA,
+                          &doesNotReturnData);
+      if (doesNotReturnData) {
+        bool popupBlocked = true;
 
-      // Let's consider external protocols as popups and let's check if the page
-      // is allowed to open them without abuse regardless of allowed events
-      if (PopupBlocker::GetPopupControlState() <= PopupBlocker::openBlocked) {
-        popupBlocked = !PopupBlocker::TryUsePopupOpeningToken();
-      } else {
-        nsCOMPtr<nsINode> loadingNode =
-            mScriptGlobal->AsOuter()->GetFrameElementInternal();
-        if (loadingNode) {
-          popupBlocked = !PopupBlocker::CanShowPopupByPermission(
-              loadingNode->NodePrincipal());
+        // Let's consider external protocols as popups and let's check if the
+        // page is allowed to open them without abuse regardless of allowed
+        // events
+        if (PopupBlocker::GetPopupControlState() <= PopupBlocker::openBlocked) {
+          popupBlocked = !PopupBlocker::TryUsePopupOpeningToken();
+        } else {
+          nsCOMPtr<nsINode> loadingNode =
+              mScriptGlobal->AsOuter()->GetFrameElementInternal();
+          if (loadingNode) {
+            popupBlocked = !PopupBlocker::CanShowPopupByPermission(
+                loadingNode->NodePrincipal());
+          }
         }
-      }
 
-      if (popupBlocked) {
-        return NS_ERROR_UNKNOWN_PROTOCOL;
+        if (popupBlocked) {
+          return NS_ERROR_UNKNOWN_PROTOCOL;
+        }
       }
     }
 

dom/html/test/test_external_protocol_iframe.html

@@ -10,30 +10,35 @@
   <div id='foo'><a href='#'>Click here to test this issue</a></div>
   <script>
 
-SimpleTest.waitForExplicitFinish();
-
-let foo = document.getElementById('foo');
-foo.addEventListener('click', _ => {
-  is(ChromeUtils.getPopupControlState(), "openAllowed", "Click events allow popups");
-  ok(!ChromeUtils.isPopupTokenUnused(), "Popup token has not been used yet");
-
-  for (let i = 0; i < 10; ++i) {
-    let ifr = document.createElement('iframe');
-    ifr.src = "foo+bar:all_good";
-    document.body.appendChild(ifr);
-
+function next() {
+  let foo = document.getElementById('foo');
+  foo.addEventListener('click', _ => {
     is(ChromeUtils.getPopupControlState(), "openAllowed", "Click events allow popups");
-    ok(ChromeUtils.isPopupTokenUnused(), "Popup token has been used!");
-  }
+    ok(!ChromeUtils.isPopupTokenUnused(), "Popup token has not been used yet");
 
-  SimpleTest.finish();
+    for (let i = 0; i < 10; ++i) {
+      let ifr = document.createElement('iframe');
+      ifr.src = "foo+bar:all_good";
+      document.body.appendChild(ifr);
 
-}, {once: true});
+      is(ChromeUtils.getPopupControlState(), "openAllowed", "Click events allow popups");
+      ok(ChromeUtils.isPopupTokenUnused(), "Popup token has been used!");
+    }
 
-setTimeout(_ => {
-  sendMouseEvent({type:'click'}, 'foo');
-}, 0);
+    SimpleTest.finish();
 
+  }, {once: true});
+
+  setTimeout(_ => {
+    sendMouseEvent({type:'click'}, 'foo');
+  }, 0);
+}
+
+SpecialPowers.pushPrefEnv({'set': [
+  ['dom.block_external_protocol_in_iframes', true],
+]}, next);
+
+SimpleTest.waitForExplicitFinish();
   </script>
 </body>
 </html>

modules/libpref/init/StaticPrefList.h

@@ -456,6 +456,19 @@ VARCACHE_PREF(
   RelaxedAtomicBool, false
 )
 
+// Block multiple external protocol URLs in iframes per single event.
+#ifdef NIGHTLY_BUILD
+#define PREF_VALUE true
+#else
+#define PREF_VALUE false
+#endif
+VARCACHE_PREF(
+  "dom.block_external_protocol_in_iframes",
+   dom_block_external_protocol_in_iframes,
+  bool, PREF_VALUE
+)
+#undef PREF_VALUE
+
 // Block multiple window.open() per single event.
 VARCACHE_PREF(
   "dom.block_multiple_popups",