diff options
Diffstat (limited to 'dom/events/DataTransferItemList.cpp')
| -rw-r--r-- | dom/events/DataTransferItemList.cpp | 642 |
1 files changed, 642 insertions, 0 deletions
diff --git a/dom/events/DataTransferItemList.cpp b/dom/events/DataTransferItemList.cpp new file mode 100644 index 0000000000..f5c84f75f8 --- /dev/null +++ b/dom/events/DataTransferItemList.cpp @@ -0,0 +1,642 @@ +/* -*- 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/. */ + +#include "DataTransferItemList.h" + +#include "nsContentUtils.h" +#include "nsIGlobalObject.h" +#include "nsIScriptObjectPrincipal.h" +#include "nsIScriptGlobalObject.h" +#include "nsIScriptContext.h" +#include "nsQueryObject.h" +#include "nsVariant.h" +#include "mozilla/BasePrincipal.h" +#include "mozilla/ContentEvents.h" +#include "mozilla/EventForwards.h" +#include "mozilla/storage/Variant.h" +#include "mozilla/dom/DataTransferItemListBinding.h" + +namespace mozilla::dom { + +NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DataTransferItemList, mDataTransfer, + mItems, mIndexedItems, mFiles) +NS_IMPL_CYCLE_COLLECTING_ADDREF(DataTransferItemList) +NS_IMPL_CYCLE_COLLECTING_RELEASE(DataTransferItemList) + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DataTransferItemList) + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY + NS_INTERFACE_MAP_ENTRY(nsISupports) +NS_INTERFACE_MAP_END + +JSObject* DataTransferItemList::WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) { + return DataTransferItemList_Binding::Wrap(aCx, this, aGivenProto); +} + +already_AddRefed<DataTransferItemList> DataTransferItemList::Clone( + DataTransfer* aDataTransfer) const { + RefPtr<DataTransferItemList> list = new DataTransferItemList(aDataTransfer); + + // We need to clone the mItems and mIndexedItems lists while keeping the same + // correspondences between the mIndexedItems and mItems lists (namely, if an + // item is in mIndexedItems, and mItems it must have the same new identity) + + // First, we copy over indexedItems, and clone every entry. Then, we go over + // mItems. For every entry, we use its mIndex property to locate it in + // mIndexedItems on the original DataTransferItemList, and then copy over the + // reference from the same index pair on the new DataTransferItemList + + list->mIndexedItems.SetLength(mIndexedItems.Length()); + list->mItems.SetLength(mItems.Length()); + + // Copy over mIndexedItems, cloning every entry + for (uint32_t i = 0; i < mIndexedItems.Length(); i++) { + const nsTArray<RefPtr<DataTransferItem>>& items = mIndexedItems[i]; + nsTArray<RefPtr<DataTransferItem>>& newItems = list->mIndexedItems[i]; + newItems.SetLength(items.Length()); + for (uint32_t j = 0; j < items.Length(); j++) { + newItems[j] = items[j]->Clone(aDataTransfer); + } + } + + // Copy over mItems, getting the actual entries from mIndexedItems + for (uint32_t i = 0; i < mItems.Length(); i++) { + uint32_t index = mItems[i]->Index(); + MOZ_ASSERT(index < mIndexedItems.Length()); + uint32_t subIndex = mIndexedItems[index].IndexOf(mItems[i]); + + // Copy over the reference + list->mItems[i] = list->mIndexedItems[index][subIndex]; + } + + return list.forget(); +} + +void DataTransferItemList::Remove(uint32_t aIndex, + nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + if (mDataTransfer->IsReadOnly()) { + aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR); + return; + } + + if (aIndex >= Length()) { + return; + } + + ClearDataHelper(mItems[aIndex], aIndex, -1, aSubjectPrincipal, aRv); +} + +DataTransferItem* DataTransferItemList::IndexedGetter(uint32_t aIndex, + bool& aFound) const { + if (aIndex >= mItems.Length()) { + aFound = false; + return nullptr; + } + + MOZ_ASSERT(mItems[aIndex]); + aFound = true; + return mItems[aIndex]; +} + +uint32_t DataTransferItemList::MozItemCount() const { + uint32_t length = mIndexedItems.Length(); + // XXX: Compat hack - Index 0 always exists due to changes in internals, but + // if it is empty, scripts using the moz* APIs should see it as not existing. + if (length == 1 && mIndexedItems[0].IsEmpty()) { + return 0; + } + return length; +} + +void DataTransferItemList::Clear(nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + if (NS_WARN_IF(mDataTransfer->IsReadOnly())) { + return; + } + + uint32_t count = Length(); + for (uint32_t i = 0; i < count; i++) { + // We always remove the last item first, to avoid moving items around in + // memory as much + Remove(Length() - 1, aSubjectPrincipal, aRv); + ENSURE_SUCCESS_VOID(aRv); + } + + MOZ_ASSERT(Length() == 0); +} + +DataTransferItem* DataTransferItemList::Add(const nsAString& aData, + const nsAString& aType, + nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + if (NS_WARN_IF(mDataTransfer->IsReadOnly())) { + return nullptr; + } + + RefPtr<nsVariantCC> data(new nsVariantCC()); + data->SetAsAString(aData); + + nsAutoString format; + mDataTransfer->GetRealFormat(aType, format); + + if (!DataTransfer::PrincipalMaySetData(format, data, &aSubjectPrincipal)) { + aRv.Throw(NS_ERROR_DOM_SECURITY_ERR); + return nullptr; + } + + // We add the textual data to index 0. We set aInsertOnly to true, as we don't + // want to update an existing entry if it is already present, as per the spec. + RefPtr<DataTransferItem> item = + SetDataWithPrincipal(format, data, 0, &aSubjectPrincipal, + /* aInsertOnly = */ true, + /* aHidden = */ false, aRv); + if (NS_WARN_IF(aRv.Failed())) { + return nullptr; + } + MOZ_ASSERT(item->Kind() != DataTransferItem::KIND_FILE); + + return item; +} + +DataTransferItem* DataTransferItemList::Add(File& aData, + nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + if (mDataTransfer->IsReadOnly()) { + return nullptr; + } + + nsCOMPtr<nsISupports> supports = do_QueryObject(&aData); + nsCOMPtr<nsIWritableVariant> data = new nsVariantCC(); + data->SetAsISupports(supports); + + nsAutoString type; + aData.GetType(type); + + if (!DataTransfer::PrincipalMaySetData(type, data, &aSubjectPrincipal)) { + aRv.Throw(NS_ERROR_DOM_SECURITY_ERR); + return nullptr; + } + + // We need to add this as a new item, as multiple files can't exist in the + // same item in the Moz DataTransfer layout. It will be appended at the end of + // the internal specced layout. + uint32_t index = mIndexedItems.Length(); + RefPtr<DataTransferItem> item = + SetDataWithPrincipal(type, data, index, &aSubjectPrincipal, + /* aInsertOnly = */ true, + /* aHidden = */ false, aRv); + if (NS_WARN_IF(aRv.Failed())) { + return nullptr; + } + MOZ_ASSERT(item->Kind() == DataTransferItem::KIND_FILE); + + return item; +} + +already_AddRefed<FileList> DataTransferItemList::Files( + nsIPrincipal* aPrincipal) { + // The DataTransfer can hold data with varying principals, coming from + // different windows. This means that permissions checks need to be made when + // accessing data from the DataTransfer. With the accessor methods, this is + // checked by DataTransferItem::Data(), however with files, we keep a cached + // live copy of the files list for spec compliance. + // + // A DataTransfer is only exposed to one webpage, chrome code and expanded + // principals related to WebExtensions content scripts or user scripts. + // The chrome code should be able to see all files on the DataTransfer, while + // the webpage and WebExtensions content scripts and user scripts should only + // be able to see the files they can see. + // + // As chrome code doesn't need as strict spec compliance as web visible code, + // we generate a new FileList object every time you access the Files list from + // chrome code, but re-use the cached one when accessing from content code. + // + // For WebExtensions content scripts (expanded principals subsuming both + // the attached web page principal and the extension principal) and + // WebExtensions user scripts (expanded principals subsuming the attached + // web page principal but not the extension principal) we also don't cache + // the FileList as for chrome code (because the webpage principal and other + // extension content scripts/user scripts principals would not be able to + // access the cached FileList when accessed by a different expanded principal + // first, see Bug 1707214). + // + // It is not legal to expose an identical DataTransfer object is to multiple + // different principals without using the `Clone` method or similar to copy it + // first. If that happens, this method will assert, and return nullptr in + // release builds. If this functionality is required in the future, a more + // advanced caching mechanism for the FileList objects will be required. + RefPtr<FileList> files; + if (aPrincipal->IsSystemPrincipal() || + // WebExtensions content scripts and user scripts. + nsContentUtils::IsExpandedPrincipal(aPrincipal)) { + files = new FileList(mDataTransfer); + GenerateFiles(files, aPrincipal); + return files.forget(); + } + + if (!mFiles) { + mFiles = new FileList(mDataTransfer); + mFilesPrincipal = aPrincipal; + RegenerateFiles(); + } + + if (!aPrincipal->Subsumes(mFilesPrincipal)) { + MOZ_ASSERT(false, + "This DataTransfer should only be accessed by the system " + "and a single principal"); + return nullptr; + } + + files = mFiles; + return files.forget(); +} + +void DataTransferItemList::MozRemoveByTypeAt(const nsAString& aType, + uint32_t aIndex, + nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + if (NS_WARN_IF(mDataTransfer->IsReadOnly() || + aIndex >= mIndexedItems.Length())) { + return; + } + + bool removeAll = aType.IsEmpty(); + + nsTArray<RefPtr<DataTransferItem>>& items = mIndexedItems[aIndex]; + uint32_t count = items.Length(); + // We remove the last item of the list repeatedly - that way we don't + // have to worry about modifying the loop iterator + if (removeAll) { + for (uint32_t i = 0; i < count; ++i) { + uint32_t index = items.Length() - 1; + MOZ_ASSERT(index == count - i - 1); + + ClearDataHelper(items[index], -1, index, aSubjectPrincipal, aRv); + if (NS_WARN_IF(aRv.Failed())) { + return; + } + } + + // items is no longer a valid reference, as removing the last element from + // it via ClearDataHelper invalidated it. so we can't MOZ_ASSERT that the + // length is now 0. + return; + } + + for (uint32_t i = 0; i < count; ++i) { + // NOTE: As this is a moz-prefixed API, it works based on internal types. + nsAutoString type; + items[i]->GetInternalType(type); + if (type == aType) { + ClearDataHelper(items[i], -1, i, aSubjectPrincipal, aRv); + return; + } + } +} + +DataTransferItem* DataTransferItemList::MozItemByTypeAt(const nsAString& aType, + uint32_t aIndex) { + if (NS_WARN_IF(aIndex >= mIndexedItems.Length())) { + return nullptr; + } + + uint32_t count = mIndexedItems[aIndex].Length(); + for (uint32_t i = 0; i < count; i++) { + RefPtr<DataTransferItem> item = mIndexedItems[aIndex][i]; + // NOTE: As this is a moz-prefixed API it works on internal types + nsString type; + item->GetInternalType(type); + if (type.Equals(aType)) { + return item; + } + } + + return nullptr; +} + +already_AddRefed<DataTransferItem> DataTransferItemList::SetDataWithPrincipal( + const nsAString& aType, nsIVariant* aData, uint32_t aIndex, + nsIPrincipal* aPrincipal, bool aInsertOnly, bool aHidden, + ErrorResult& aRv) { + if (aIndex < mIndexedItems.Length()) { + nsTArray<RefPtr<DataTransferItem>>& items = mIndexedItems[aIndex]; + uint32_t count = items.Length(); + for (uint32_t i = 0; i < count; i++) { + RefPtr<DataTransferItem> item = items[i]; + nsString type; + item->GetInternalType(type); + if (type.Equals(aType)) { + if (NS_WARN_IF(aInsertOnly)) { + aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR); + return nullptr; + } + + // don't allow replacing data that has a stronger principal + bool subsumes; + if (NS_WARN_IF(item->Principal() && aPrincipal && + (NS_FAILED(aPrincipal->Subsumes(item->Principal(), + &subsumes)) || + !subsumes))) { + aRv.Throw(NS_ERROR_DOM_SECURITY_ERR); + return nullptr; + } + item->SetPrincipal(aPrincipal); + + DataTransferItem::eKind oldKind = item->Kind(); + item->SetData(aData); + + mDataTransfer->TypesListMayHaveChanged(); + + if (aIndex != 0) { + // If the item changes from being a file to not a file or vice-versa, + // its presence in the mItems array may need to change. + if (item->Kind() == DataTransferItem::KIND_FILE && + oldKind != DataTransferItem::KIND_FILE) { + // not file => file + mItems.AppendElement(item); + } else if (item->Kind() != DataTransferItem::KIND_FILE && + oldKind == DataTransferItem::KIND_FILE) { + // file => not file + mItems.RemoveElement(item); + } + } + + // Regenerate the Files array if we have modified a file's status + if (item->Kind() == DataTransferItem::KIND_FILE || + oldKind == DataTransferItem::KIND_FILE) { + RegenerateFiles(); + } + + return item.forget(); + } + } + } else { + // Make sure that we aren't adding past the end of the mIndexedItems array. + // XXX Should this be a MOZ_ASSERT instead? + aIndex = mIndexedItems.Length(); + } + + // Add the new item + RefPtr<DataTransferItem> item = + AppendNewItem(aIndex, aType, aData, aPrincipal, aHidden); + + if (item->Kind() == DataTransferItem::KIND_FILE) { + RegenerateFiles(); + } + + return item.forget(); +} + +DataTransferItem* DataTransferItemList::AppendNewItem(uint32_t aIndex, + const nsAString& aType, + nsIVariant* aData, + nsIPrincipal* aPrincipal, + bool aHidden) { + if (mIndexedItems.Length() <= aIndex) { + MOZ_ASSERT(mIndexedItems.Length() == aIndex); + mIndexedItems.AppendElement(); + } + RefPtr<DataTransferItem> item = new DataTransferItem(mDataTransfer, aType); + item->SetIndex(aIndex); + item->SetPrincipal(aPrincipal); + item->SetData(aData); + item->SetChromeOnly(aHidden); + + mIndexedItems[aIndex].AppendElement(item); + + // We only want to add the item to the main mItems list if the index we are + // adding to is 0, or the item we are adding is a file. If we add an item + // which is not a file to a non-zero index, invariants could be broken. + // (namely the invariant that there are not 2 non-file entries in the items + // array with the same type). + // + // We also want to update our DataTransfer's type list any time we're adding a + // KIND_FILE item, or an item at index 0. + if (item->Kind() == DataTransferItem::KIND_FILE || aIndex == 0) { + if (!aHidden) { + mItems.AppendElement(item); + } + mDataTransfer->TypesListMayHaveChanged(); + } + + return item; +} + +void DataTransferItemList::GetTypes(nsTArray<nsString>& aTypes, + CallerType aCallerType) const { + MOZ_ASSERT(aTypes.IsEmpty()); + + if (mIndexedItems.IsEmpty()) { + return; + } + + bool foundFile = false; + for (const RefPtr<DataTransferItem>& item : mIndexedItems[0]) { + MOZ_ASSERT(item); + + // XXX Why don't we check the caller type with item's permission only + // for "Files"? + if (!foundFile) { + foundFile = item->Kind() == DataTransferItem::KIND_FILE; + } + + if (item->ChromeOnly() && aCallerType != CallerType::System) { + continue; + } + + // NOTE: The reason why we get the internal type here is because we want + // kFileMime to appear in the types list for backwards compatibility + // reasons. + nsAutoString type; + item->GetInternalType(type); + if (item->Kind() != DataTransferItem::KIND_FILE || + type.EqualsASCII(kFileMime)) { + aTypes.AppendElement(type); + } + } + + // Additional files will be added at a non-zero index. + if (!foundFile) { + for (uint32_t i = 1; i < mIndexedItems.Length(); i++) { + for (const RefPtr<DataTransferItem>& item : mIndexedItems[i]) { + MOZ_ASSERT(item); + + foundFile = item->Kind() == DataTransferItem::KIND_FILE; + if (foundFile) { + break; + } + } + } + } + + if (foundFile) { + aTypes.AppendElement(u"Files"_ns); + } +} + +bool DataTransferItemList::HasType(const nsAString& aType) const { + MOZ_ASSERT(!aType.EqualsASCII("Files"), "Use HasFile instead"); + if (mIndexedItems.IsEmpty()) { + return false; + } + + for (const RefPtr<DataTransferItem>& item : mIndexedItems[0]) { + if (item->IsInternalType(aType)) { + return true; + } + } + return false; +} + +bool DataTransferItemList::HasFile() const { + if (mIndexedItems.IsEmpty()) { + return false; + } + + for (const RefPtr<DataTransferItem>& item : mIndexedItems[0]) { + if (item->Kind() == DataTransferItem::KIND_FILE) { + return true; + } + } + return false; +} + +const nsTArray<RefPtr<DataTransferItem>>* DataTransferItemList::MozItemsAt( + uint32_t aIndex) // -- INDEXED +{ + if (aIndex >= mIndexedItems.Length()) { + return nullptr; + } + + return &mIndexedItems[aIndex]; +} + +void DataTransferItemList::PopIndexZero() { + MOZ_ASSERT(mIndexedItems.Length() > 1); + MOZ_ASSERT(mIndexedItems[0].IsEmpty()); + + mIndexedItems.RemoveElementAt(0); + + // Update the index of every element which has now been shifted + for (uint32_t i = 0; i < mIndexedItems.Length(); i++) { + nsTArray<RefPtr<DataTransferItem>>& items = mIndexedItems[i]; + for (uint32_t j = 0; j < items.Length(); j++) { + items[j]->SetIndex(i); + } + } +} + +void DataTransferItemList::ClearAllItems() { + // We always need to have index 0, so don't delete that one + mItems.Clear(); + mIndexedItems.Clear(); + mIndexedItems.SetLength(1); + mDataTransfer->TypesListMayHaveChanged(); + + // Re-generate files (into an empty list) + RegenerateFiles(); +} + +void DataTransferItemList::ClearDataHelper(DataTransferItem* aItem, + uint32_t aIndexHint, + uint32_t aMozOffsetHint, + nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + MOZ_ASSERT(aItem); + if (NS_WARN_IF(mDataTransfer->IsReadOnly())) { + return; + } + + if (aItem->Principal() && !aSubjectPrincipal.Subsumes(aItem->Principal())) { + aRv.Throw(NS_ERROR_DOM_SECURITY_ERR); + return; + } + + // Check if the aIndexHint is actually the index, and then remove the item + // from aItems + bool found; + if (IndexedGetter(aIndexHint, found) == aItem) { + mItems.RemoveElementAt(aIndexHint); + } else { + mItems.RemoveElement(aItem); + } + + // Check if the aMozIndexHint and aMozOffsetHint are actually the index and + // offset, and then remove them from mIndexedItems + MOZ_ASSERT(aItem->Index() < mIndexedItems.Length()); + nsTArray<RefPtr<DataTransferItem>>& items = mIndexedItems[aItem->Index()]; + if (aMozOffsetHint < items.Length() && aItem == items[aMozOffsetHint]) { + items.RemoveElementAt(aMozOffsetHint); + } else { + items.RemoveElement(aItem); + } + + mDataTransfer->TypesListMayHaveChanged(); + + // Check if we should remove the index. We never remove index 0. + if (items.Length() == 0 && aItem->Index() != 0) { + mIndexedItems.RemoveElementAt(aItem->Index()); + + // Update the index of every element which has now been shifted + for (uint32_t i = aItem->Index(); i < mIndexedItems.Length(); i++) { + nsTArray<RefPtr<DataTransferItem>>& items = mIndexedItems[i]; + for (uint32_t j = 0; j < items.Length(); j++) { + items[j]->SetIndex(i); + } + } + } + + // Give the removed item the invalid index + aItem->SetIndex(-1); + + if (aItem->Kind() == DataTransferItem::KIND_FILE) { + RegenerateFiles(); + } +} + +void DataTransferItemList::RegenerateFiles() { + // We don't want to regenerate the files list unless we already have a files + // list. That way we can avoid the unnecessary work if the user never touches + // the files list. + if (mFiles) { + // We clear the list rather than performing smaller updates, because it + // simplifies the logic greatly on this code path, which should be very + // infrequently used. + mFiles->Clear(); + + DataTransferItemList::GenerateFiles(mFiles, mFilesPrincipal); + } +} + +void DataTransferItemList::GenerateFiles(FileList* aFiles, + nsIPrincipal* aFilesPrincipal) { + MOZ_ASSERT(aFiles); + MOZ_ASSERT(aFilesPrincipal); + + // For non-system principals, the Files list should be empty if the + // DataTransfer is protected. + if (!aFilesPrincipal->IsSystemPrincipal() && mDataTransfer->IsProtected()) { + return; + } + + uint32_t count = Length(); + for (uint32_t i = 0; i < count; i++) { + bool found; + RefPtr<DataTransferItem> item = IndexedGetter(i, found); + MOZ_ASSERT(found); + + if (item->Kind() == DataTransferItem::KIND_FILE) { + RefPtr<File> file = item->GetAsFile(*aFilesPrincipal, IgnoreErrors()); + if (NS_WARN_IF(!file)) { + continue; + } + aFiles->Append(file); + } + } +} + +} // namespace mozilla::dom |