Bug 1799156 - Filter unknown DataTransferItem flavors. r=nika

Differential Revision: https://phabricator.services.mozilla.com/D161487

dom/base/nsContentUtils.cpp

@@ -7761,12 +7761,37 @@ void nsContentUtils::SetKeyboardIndicatorsOnRemoteChildren(
   });
 }
 
+bool nsContentUtils::IPCDataTransferItemHasKnownFlavor(
+    const IPCDataTransferItem& aItem) {
+  // Unknown types are converted to kCustomTypesMime.
+  // FIXME(bug 1776879) text/plain is converted to text/unicode still.
+  if (aItem.flavor().EqualsASCII(kCustomTypesMime) ||
+      aItem.flavor().EqualsASCII(kUnicodeMime)) {
+    return true;
+  }
+
+  for (const char* format : DataTransfer::kKnownFormats) {
+    if (aItem.flavor().EqualsASCII(format)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 nsresult nsContentUtils::IPCTransferableToTransferable(
     const IPCDataTransfer& aDataTransfer, bool aAddDataFlavor,
-    nsITransferable* aTransferable) {
+    nsITransferable* aTransferable, const bool aFilterUnknownFlavors) {
   nsresult rv;
   const nsTArray<IPCDataTransferItem>& items = aDataTransfer.items();
   for (const auto& item : items) {
+    if (aFilterUnknownFlavors && !IPCDataTransferItemHasKnownFlavor(item)) {
+      NS_WARNING(
+          "Ignoring unknown flavor in "
+          "nsContentUtils::IPCTransferableToTransferable");
+      continue;
+    }
+
     if (aAddDataFlavor) {
       aTransferable->AddDataFlavor(item.flavor().get());
     }
@@ -7836,11 +7861,11 @@ nsresult nsContentUtils::IPCTransferableToTransferable(
     const IPCDataTransfer& aDataTransfer, const bool& aIsPrivateData,
     nsIPrincipal* aRequestingPrincipal,
     const nsContentPolicyType& aContentPolicyType, bool aAddDataFlavor,
-    nsITransferable* aTransferable) {
+    nsITransferable* aTransferable, const bool aFilterUnknownFlavors) {
   aTransferable->SetIsPrivateData(aIsPrivateData);
 
   nsresult rv = IPCTransferableToTransferable(aDataTransfer, aAddDataFlavor,
-                                              aTransferable);
+                                              aTransferable, aFilterUnknownFlavors);
   NS_ENSURE_SUCCESS(rv, rv);
 
   aTransferable->SetRequestingPrincipal(aRequestingPrincipal);

dom/base/nsContentUtils.h

@@ -2872,15 +2872,18 @@ class nsContentUtils {
    */
   static bool IsFlavorImage(const nsACString& aFlavor);
 
+  static bool IPCDataTransferItemHasKnownFlavor(
+      const mozilla::dom::IPCDataTransferItem& aItem);
+
   static nsresult IPCTransferableToTransferable(
       const mozilla::dom::IPCDataTransfer& aDataTransfer, bool aAddDataFlavor,
-      nsITransferable* aTransferable);
+      nsITransferable* aTransferable, const bool aFilterUnknownFlavors);
 
   static nsresult IPCTransferableToTransferable(
       const mozilla::dom::IPCDataTransfer& aDataTransfer,
       const bool& aIsPrivateData, nsIPrincipal* aRequestingPrincipal,
       const nsContentPolicyType& aContentPolicyType, bool aAddDataFlavor,
-      nsITransferable* aTransferable);
+      nsITransferable* aTransferable, const bool aFilterUnknownFlavors);
 
   static nsresult IPCTransferableItemToVariant(
       const mozilla::dom::IPCDataTransferItem& aDataTransferItem,

dom/events/DataTransfer.cpp

@@ -888,29 +888,6 @@ already_AddRefed<nsITransferable> DataTransfer::GetTransferable(
   const uint32_t baseLength = sizeof(uint32_t) + 1;
   uint32_t totalCustomLength = baseLength;
 
-  const char* knownFormats[] = {kTextMime,
-                                kHTMLMime,
-                                kNativeHTMLMime,
-                                kRTFMime,
-                                kURLMime,
-                                kURLDataMime,
-                                kURLDescriptionMime,
-                                kURLPrivateMime,
-                                kPNGImageMime,
-                                kJPEGImageMime,
-                                kGIFImageMime,
-                                kNativeImageMime,
-                                kFileMime,
-                                kFilePromiseMime,
-                                kFilePromiseURLMime,
-                                kFilePromiseDestFilename,
-                                kFilePromiseDirectoryMime,
-                                kMozTextInternal,
-                                kHTMLContext,
-                                kHTMLInfo,
-                                kImageRequestMime,
-                                kPDFJSMime};
-
   /*
    * Two passes are made here to iterate over all of the types. First, look for
    * any types that are not in the list of known types. For this pass,
@@ -946,8 +923,8 @@ already_AddRefed<nsITransferable> DataTransfer::GetTransferable(
 
       // If the data is of one of the well-known formats, use it directly.
       bool isCustomFormat = true;
-      for (uint32_t f = 0; f < ArrayLength(knownFormats); f++) {
+      for (const char* format : kKnownFormats) {
-        if (type.EqualsASCII(knownFormats[f])) {
+        if (type.EqualsASCII(format)) {
           isCustomFormat = false;
           break;
         }

dom/events/DataTransfer.h

@@ -393,6 +393,30 @@ class DataTransfer final : public nsISupports, public nsWrapperCache {
                                              bool aPlainTextOnly,
                                              nsTArray<nsCString>* aResult);
 
+  // Formats that are "known" and won't be converted to the kCustomTypesMime.
+  static inline const char* const kKnownFormats[] = {kTextMime,
+                                                     kHTMLMime,
+                                                     kNativeHTMLMime,
+                                                     kRTFMime,
+                                                     kURLMime,
+                                                     kURLDataMime,
+                                                     kURLDescriptionMime,
+                                                     kURLPrivateMime,
+                                                     kPNGImageMime,
+                                                     kJPEGImageMime,
+                                                     kGIFImageMime,
+                                                     kNativeImageMime,
+                                                     kFileMime,
+                                                     kFilePromiseMime,
+                                                     kFilePromiseURLMime,
+                                                     kFilePromiseDestFilename,
+                                                     kFilePromiseDirectoryMime,
+                                                     kMozTextInternal,
+                                                     kHTMLContext,
+                                                     kHTMLInfo,
+                                                     kImageRequestMime,
+                                                     kPDFJSMime};
+
  protected:
   // caches text and uri-list data formats that exist in the drag service or
   // clipboard for retrieval later.

dom/events/RemoteDragStartData.cpp

@@ -43,6 +43,13 @@ void RemoteDragStartData::AddInitialDnDDataTo(
   for (uint32_t i = 0; i < mDataTransfer.Length(); ++i) {
     nsTArray<IPCDataTransferItem>& itemArray = mDataTransfer[i].items();
     for (auto& item : itemArray) {
+      if (!nsContentUtils::IPCDataTransferItemHasKnownFlavor(item)) {
+        NS_WARNING(
+            "Ignoring unknown flavor in "
+            "RemoteDragStartData::AddInitialDnDDataTo");
+        continue;
+      }
+
       RefPtr<nsVariantCC> variant = new nsVariantCC();
       // Special case kFilePromiseMime so that we get the right
       // nsIFlavorDataProvider for it.

dom/ipc/BrowserChild.cpp

@@ -2242,7 +2242,7 @@ mozilla::ipc::IPCResult BrowserChild::RecvPasteTransferable(
 
   rv = nsContentUtils::IPCTransferableToTransferable(
       aDataTransfer, aIsPrivateData, aRequestingPrincipal, aContentPolicyType,
-      true /* aAddDataFlavor */, trans);
+      true /* aAddDataFlavor */, trans, false /* aFilterUnknownFlavors */);
   NS_ENSURE_SUCCESS(rv, IPC_OK());
 
   nsCOMPtr<nsIDocShell> ourDocShell = do_GetInterface(WebNavigation());

dom/ipc/ContentParent.cpp

@@ -3417,7 +3417,7 @@ mozilla::ipc::IPCResult ContentParent::RecvSetClipboard(
 
   rv = nsContentUtils::IPCTransferableToTransferable(
       aDataTransfer, aIsPrivateData, aRequestingPrincipal, aContentPolicyType,
-      true /* aAddDataFlavor */, trans);
+      true /* aAddDataFlavor */, trans, true /* aFilterUnknownFlavors */);
   NS_ENSURE_SUCCESS(rv, IPC_OK());
 
   clipboard->SetData(trans, nullptr, aWhichClipboard);

widget/nsClipboardProxy.cpp

@@ -57,7 +57,8 @@ nsClipboardProxy::GetData(nsITransferable* aTransferable,
   ContentChild::GetSingleton()->SendGetClipboard(types, aWhichClipboard,
                                                  &dataTransfer);
   return nsContentUtils::IPCTransferableToTransferable(
-      dataTransfer, false /* aAddDataFlavor */, aTransferable);
+      dataTransfer, false /* aAddDataFlavor */, aTransferable,
+      false /* aFilterUnknownFlavors */);
 }
 
 NS_IMETHODIMP
@@ -136,7 +137,8 @@ RefPtr<GenericPromise> nsClipboardProxy::AsyncGetData(
           /* resolve */
           [promise, transferable](const IPCDataTransfer& ipcDataTransfer) {
             nsresult rv = nsContentUtils::IPCTransferableToTransferable(
-                ipcDataTransfer, false /* aAddDataFlavor */, transferable);
+                ipcDataTransfer, false /* aAddDataFlavor */, transferable,
+                false /* aFilterUnknownFlavors */);
             if (NS_FAILED(rv)) {
               promise->Reject(rv, __func__);
               return;