diff options
Diffstat (limited to 'dom/events/DataTransferItem.cpp')
| -rw-r--r-- | dom/events/DataTransferItem.cpp | 594 |
1 files changed, 594 insertions, 0 deletions
diff --git a/dom/events/DataTransferItem.cpp b/dom/events/DataTransferItem.cpp new file mode 100644 index 0000000000..8b1aa1902c --- /dev/null +++ b/dom/events/DataTransferItem.cpp @@ -0,0 +1,594 @@ +/* -*- 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 "DataTransferItem.h" +#include "DataTransferItemList.h" + +#include "mozilla/Attributes.h" +#include "mozilla/BasePrincipal.h" +#include "mozilla/ContentEvents.h" +#include "mozilla/EventForwards.h" +#include "mozilla/StaticPrefs_dom.h" +#include "mozilla/dom/BlobImpl.h" +#include "mozilla/dom/DataTransferItemBinding.h" +#include "mozilla/dom/Directory.h" +#include "mozilla/dom/FileSystem.h" +#include "mozilla/dom/FileSystemDirectoryEntry.h" +#include "mozilla/dom/FileSystemFileEntry.h" +#include "imgIContainer.h" +#include "imgITools.h" +#include "nsComponentManagerUtils.h" +#include "nsGlobalWindowInner.h" +#include "nsIClipboard.h" +#include "nsIFile.h" +#include "nsIInputStream.h" +#include "nsISupportsPrimitives.h" +#include "nsIScriptObjectPrincipal.h" +#include "nsNetUtil.h" +#include "nsQueryObject.h" +#include "nsContentUtils.h" +#include "nsThreadUtils.h" +#include "nsVariant.h" + +namespace { + +struct FileMimeNameData { + const char* mMimeName; + const char* mFileName; +}; + +FileMimeNameData kFileMimeNameMap[] = { + {kFileMime, "GenericFileName"}, + {kPNGImageMime, "GenericImageNamePNG"}, +}; + +} // anonymous namespace + +namespace mozilla::dom { + +NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DataTransferItem, mData, mPrincipal, + mDataTransfer, mCachedFile) +NS_IMPL_CYCLE_COLLECTING_ADDREF(DataTransferItem) +NS_IMPL_CYCLE_COLLECTING_RELEASE(DataTransferItem) + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DataTransferItem) + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY + NS_INTERFACE_MAP_ENTRY(nsISupports) +NS_INTERFACE_MAP_END + +JSObject* DataTransferItem::WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) { + return DataTransferItem_Binding::Wrap(aCx, this, aGivenProto); +} + +already_AddRefed<DataTransferItem> DataTransferItem::Clone( + DataTransfer* aDataTransfer) const { + MOZ_ASSERT(aDataTransfer); + + RefPtr<DataTransferItem> it = new DataTransferItem(aDataTransfer, mType); + + // Copy over all of the fields + it->mKind = mKind; + it->mIndex = mIndex; + it->mData = mData; + it->mPrincipal = mPrincipal; + it->mChromeOnly = mChromeOnly; + + return it.forget(); +} + +void DataTransferItem::SetData(nsIVariant* aData) { + // Invalidate our file cache, we will regenerate it with the new data + mCachedFile = nullptr; + + if (!aData) { + // We are holding a temporary null which will later be filled. + // These are provided by the system, and have guaranteed properties about + // their kind based on their type. + MOZ_ASSERT(!mType.IsEmpty()); + // This type should not be provided by the OS. + MOZ_ASSERT(!mType.EqualsASCII(kNativeImageMime)); + + mKind = KIND_STRING; + for (uint32_t i = 0; i < ArrayLength(kFileMimeNameMap); ++i) { + if (mType.EqualsASCII(kFileMimeNameMap[i].mMimeName)) { + mKind = KIND_FILE; + break; + } + } + + mData = nullptr; + return; + } + + mData = aData; + mKind = KindFromData(mData); +} + +/* static */ DataTransferItem::eKind DataTransferItem::KindFromData( + nsIVariant* aData) { + nsCOMPtr<nsISupports> supports; + nsresult rv = aData->GetAsISupports(getter_AddRefs(supports)); + if (NS_SUCCEEDED(rv) && supports) { + // Check if we have one of the supported file data formats + if (RefPtr<Blob>(do_QueryObject(supports)) || + nsCOMPtr<BlobImpl>(do_QueryInterface(supports)) || + nsCOMPtr<nsIFile>(do_QueryInterface(supports))) { + return KIND_FILE; + } + + if (StaticPrefs::dom_events_dataTransfer_imageAsFile_enabled()) { + // Firefox internally uses imgIContainer to represent images being + // copied/dragged. These need to be encoded to PNG files. + if (nsCOMPtr<imgIContainer>(do_QueryInterface(supports))) { + return KIND_FILE; + } + } + } + + nsAutoString string; + // If we can't get the data type as a string, that means that the object + // should be considered to be of the "other" type. This is impossible + // through the APIs defined by the spec, but we provide extra Moz* APIs, + // which allow setting of non-string data. We determine whether we can + // consider it a string, by calling GetAsAString, and checking for success. + rv = aData->GetAsAString(string); + if (NS_SUCCEEDED(rv)) { + return KIND_STRING; + } + + return KIND_OTHER; +} + +void DataTransferItem::FillInExternalData() { + if (mData) { + return; + } + + NS_ConvertUTF16toUTF8 utf8format(mType); + const char* format = utf8format.get(); + if (strcmp(format, "text/uri-list") == 0) { + format = kURLDataMime; + } + + nsCOMPtr<nsITransferable> trans = mDataTransfer->GetTransferable(); + if (!trans) { + trans = do_CreateInstance("@mozilla.org/widget/transferable;1"); + if (NS_WARN_IF(!trans)) { + return; + } + + trans->Init(nullptr); + trans->AddDataFlavor(format); + + if (mDataTransfer->GetEventMessage() == ePaste) { + MOZ_ASSERT(mIndex == 0, "index in clipboard must be 0"); + + nsCOMPtr<nsIClipboard> clipboard = + do_GetService("@mozilla.org/widget/clipboard;1"); + if (!clipboard || mDataTransfer->ClipboardType() < 0) { + return; + } + + nsCOMPtr<nsIGlobalObject> global = mDataTransfer->GetGlobal(); + WindowContext* windowContext = nullptr; + if (global) { + const auto* innerWindow = global->GetAsInnerWindow(); + windowContext = innerWindow ? innerWindow->GetWindowContext() : nullptr; + } + MOZ_ASSERT(windowContext); + nsresult rv = clipboard->GetData(trans, mDataTransfer->ClipboardType(), + windowContext); + if (NS_WARN_IF(NS_FAILED(rv))) { + return; + } + } else { + nsCOMPtr<nsIDragSession> dragSession = nsContentUtils::GetDragSession(); + if (!dragSession) { + return; + } + + nsresult rv = dragSession->GetData(trans, mIndex); + if (NS_WARN_IF(NS_FAILED(rv))) { + return; + } + } + } + + nsCOMPtr<nsISupports> data; + nsresult rv = trans->GetTransferData(format, getter_AddRefs(data)); + if (NS_WARN_IF(NS_FAILED(rv) || !data)) { + return; + } + + // Fill the variant + RefPtr<nsVariantCC> variant = new nsVariantCC(); + + eKind oldKind = Kind(); + if (oldKind == KIND_FILE) { + // Because this is an external piece of data, mType is one of kFileMime, + // kPNGImageMime, kJPEGImageMime, or kGIFImageMime. Some of these types + // are passed in as a nsIInputStream which must be converted to a + // dom::File before storing. + if (nsCOMPtr<nsIInputStream> istream = do_QueryInterface(data)) { + RefPtr<File> file = CreateFileFromInputStream(istream); + if (NS_WARN_IF(!file)) { + return; + } + data = do_QueryObject(file); + } + variant->SetAsISupports(data); + } else { + // We have an external piece of string data. Extract it and store it in the + // variant + MOZ_ASSERT(oldKind == KIND_STRING); + + nsCOMPtr<nsISupportsString> supportsstr = do_QueryInterface(data); + if (supportsstr) { + nsAutoString str; + supportsstr->GetData(str); + variant->SetAsAString(str); + } else { + nsCOMPtr<nsISupportsCString> supportscstr = do_QueryInterface(data); + if (supportscstr) { + nsAutoCString str; + supportscstr->GetData(str); + variant->SetAsACString(str); + } + } + } + + SetData(variant); + + if (oldKind != Kind()) { + NS_WARNING( + "Clipboard data provided by the OS does not match predicted kind"); + mDataTransfer->TypesListMayHaveChanged(); + } +} + +void DataTransferItem::GetType(nsAString& aType) { + // If we don't have a File, we can just put whatever our recorded internal + // type is. + if (Kind() != KIND_FILE) { + aType = mType; + return; + } + + // If we do have a File, then we need to look at our File object to discover + // what its mime type is. We can use the System Principal here, as this + // information should be avaliable even if the data is currently inaccessible + // (for example during a dragover). + // + // XXX: This seems inefficient, as it seems like we should be able to get this + // data without getting the entire File object, which may require talking to + // the OS. + ErrorResult rv; + RefPtr<File> file = GetAsFile(*nsContentUtils::GetSystemPrincipal(), rv); + MOZ_ASSERT(!rv.Failed(), "Failed to get file data with system principal"); + + // If we don't actually have a file, fall back to returning the internal type. + if (NS_WARN_IF(!file)) { + aType = mType; + return; + } + + file->GetType(aType); +} + +already_AddRefed<File> DataTransferItem::GetAsFile( + nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv) { + // This is done even if we have an mCachedFile, as it performs the necessary + // permissions checks to ensure that we are allowed to access this type. + nsCOMPtr<nsIVariant> data = Data(&aSubjectPrincipal, aRv); + if (NS_WARN_IF(!data || aRv.Failed())) { + return nullptr; + } + + // We have to check our kind after getting the data, because if we have + // external data and the OS lied to us (which unfortunately does happen + // sometimes), then we might not have the same type of data as we did coming + // into this function. + if (NS_WARN_IF(mKind != KIND_FILE)) { + return nullptr; + } + + // Generate the dom::File from the stored data, caching it so that the + // same object is returned in the future. + if (!mCachedFile) { + nsCOMPtr<nsISupports> supports; + aRv = data->GetAsISupports(getter_AddRefs(supports)); + MOZ_ASSERT(!aRv.Failed() && supports, + "File objects should be stored as nsISupports variants"); + if (aRv.Failed() || !supports) { + return nullptr; + } + + if (RefPtr<Blob> blob = do_QueryObject(supports)) { + mCachedFile = blob->ToFile(); + } else { + nsCOMPtr<nsIGlobalObject> global = mDataTransfer->GetGlobal(); + if (NS_WARN_IF(!global)) { + return nullptr; + } + + if (nsCOMPtr<BlobImpl> blobImpl = do_QueryInterface(supports)) { + MOZ_ASSERT(blobImpl->IsFile()); + mCachedFile = File::Create(global, blobImpl); + if (NS_WARN_IF(!mCachedFile)) { + return nullptr; + } + } else if (nsCOMPtr<nsIFile> ifile = do_QueryInterface(supports)) { + mCachedFile = File::CreateFromFile(global, ifile); + if (NS_WARN_IF(!mCachedFile)) { + return nullptr; + } + } else if (nsCOMPtr<imgIContainer> img = do_QueryInterface(supports)) { + nsCOMPtr<imgITools> imgTools = + do_CreateInstance("@mozilla.org/image/tools;1"); + + nsCOMPtr<nsIInputStream> inputStream; + nsresult rv = imgTools->EncodeImage(img, "image/png"_ns, u""_ns, + getter_AddRefs(inputStream)); + if (NS_WARN_IF(NS_FAILED(rv))) { + return nullptr; + } + + mCachedFile = CreateFileFromInputStream( + inputStream, "GenericImageNamePNG", u"image/png"_ns); + if (NS_WARN_IF(!mCachedFile)) { + return nullptr; + } + } else { + MOZ_ASSERT(false, "One of the above code paths should be taken"); + return nullptr; + } + } + } + + RefPtr<File> file = mCachedFile; + return file.forget(); +} + +already_AddRefed<FileSystemEntry> DataTransferItem::GetAsEntry( + nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv) { + RefPtr<File> file = GetAsFile(aSubjectPrincipal, aRv); + if (NS_WARN_IF(aRv.Failed()) || !file) { + return nullptr; + } + + nsCOMPtr<nsIGlobalObject> global = mDataTransfer->GetGlobal(); + if (NS_WARN_IF(!global)) { + return nullptr; + } + + RefPtr<FileSystem> fs = FileSystem::Create(global); + RefPtr<FileSystemEntry> entry; + BlobImpl* impl = file->Impl(); + MOZ_ASSERT(impl); + + if (impl->IsDirectory()) { + nsAutoString fullpath; + impl->GetMozFullPathInternal(fullpath, aRv); + if (aRv.Failed()) { + aRv.SuppressException(); + return nullptr; + } + + nsCOMPtr<nsIFile> directoryFile; + // fullPath is already in unicode, we don't have to use + // NS_NewNativeLocalFile. + nsresult rv = + NS_NewLocalFile(fullpath, true, getter_AddRefs(directoryFile)); + if (NS_WARN_IF(NS_FAILED(rv))) { + return nullptr; + } + + RefPtr<Directory> directory = Directory::Create(global, directoryFile); + entry = new FileSystemDirectoryEntry(global, directory, nullptr, fs); + } else { + entry = new FileSystemFileEntry(global, file, nullptr, fs); + } + + Sequence<RefPtr<FileSystemEntry>> entries; + if (!entries.AppendElement(entry, fallible)) { + return nullptr; + } + + fs->CreateRoot(entries); + return entry.forget(); +} + +already_AddRefed<File> DataTransferItem::CreateFileFromInputStream( + nsIInputStream* aStream) { + const char* key = nullptr; + for (uint32_t i = 0; i < ArrayLength(kFileMimeNameMap); ++i) { + if (mType.EqualsASCII(kFileMimeNameMap[i].mMimeName)) { + key = kFileMimeNameMap[i].mFileName; + break; + } + } + if (!key) { + MOZ_ASSERT_UNREACHABLE("Unsupported mime type"); + key = "GenericFileName"; + } + + return CreateFileFromInputStream(aStream, key, mType); +} + +already_AddRefed<File> DataTransferItem::CreateFileFromInputStream( + nsIInputStream* aStream, const char* aFileNameKey, + const nsAString& aContentType) { + nsAutoString fileName; + nsresult rv = nsContentUtils::GetLocalizedString( + nsContentUtils::eDOM_PROPERTIES, aFileNameKey, fileName); + if (NS_WARN_IF(NS_FAILED(rv))) { + return nullptr; + } + + uint64_t available; + void* data = nullptr; + rv = NS_ReadInputStreamToBuffer(aStream, &data, -1, &available); + if (NS_WARN_IF(NS_FAILED(rv))) { + return nullptr; + } + + nsCOMPtr<nsIGlobalObject> global = mDataTransfer->GetGlobal(); + if (NS_WARN_IF(!global)) { + return nullptr; + } + + return File::CreateMemoryFileWithLastModifiedNow(global, data, available, + fileName, aContentType); +} + +void DataTransferItem::GetAsString(FunctionStringCallback* aCallback, + nsIPrincipal& aSubjectPrincipal, + ErrorResult& aRv) { + if (!aCallback) { + return; + } + + // Theoretically this should be done inside of the runnable, as it might be an + // expensive operation on some systems, however we wouldn't get access to the + // NS_ERROR_DOM_SECURITY_ERROR messages which may be raised by this method. + nsCOMPtr<nsIVariant> data = Data(&aSubjectPrincipal, aRv); + if (NS_WARN_IF(!data || aRv.Failed())) { + return; + } + + // We have to check our kind after getting the data, because if we have + // external data and the OS lied to us (which unfortunately does happen + // sometimes), then we might not have the same type of data as we did coming + // into this function. + if (NS_WARN_IF(mKind != KIND_STRING)) { + return; + } + + nsAutoString stringData; + nsresult rv = data->GetAsAString(stringData); + if (NS_WARN_IF(NS_FAILED(rv))) { + return; + } + + // Dispatch the callback to the main thread + class GASRunnable final : public Runnable { + public: + GASRunnable(FunctionStringCallback* aCallback, const nsAString& aStringData) + : mozilla::Runnable("GASRunnable"), + mCallback(aCallback), + mStringData(aStringData) {} + + // MOZ_CAN_RUN_SCRIPT_BOUNDARY until runnables are opted into + // MOZ_CAN_RUN_SCRIPT. See bug 1535398. + MOZ_CAN_RUN_SCRIPT_BOUNDARY + NS_IMETHOD Run() override { + ErrorResult rv; + mCallback->Call(mStringData, rv); + NS_WARNING_ASSERTION(!rv.Failed(), "callback failed"); + return rv.StealNSResult(); + } + + private: + const RefPtr<FunctionStringCallback> mCallback; + nsString mStringData; + }; + + RefPtr<GASRunnable> runnable = new GASRunnable(aCallback, stringData); + + if (nsCOMPtr<nsIGlobalObject> global = mDataTransfer->GetGlobal()) { + rv = global->Dispatch(runnable.forget()); + } else { + rv = NS_DispatchToMainThread(runnable); + } + if (NS_FAILED(rv)) { + NS_WARNING( + "Dispatch to main thread Failed in " + "DataTransferItem::GetAsString!"); + } +} + +already_AddRefed<nsIVariant> DataTransferItem::DataNoSecurityCheck() { + if (!mData) { + FillInExternalData(); + } + nsCOMPtr<nsIVariant> data = mData; + return data.forget(); +} + +already_AddRefed<nsIVariant> DataTransferItem::Data(nsIPrincipal* aPrincipal, + ErrorResult& aRv) { + MOZ_ASSERT(aPrincipal); + + // If the inbound principal is system, we can skip the below checks, as + // they will trivially succeed. + if (aPrincipal->IsSystemPrincipal()) { + return DataNoSecurityCheck(); + } + + // We should not allow raw data to be accessed from a Protected DataTransfer. + // We don't prevent this access if the accessing document is Chrome. + if (mDataTransfer->IsProtected()) { + return nullptr; + } + + nsCOMPtr<nsIVariant> variant = DataNoSecurityCheck(); + + MOZ_ASSERT(!ChromeOnly(), + "Non-chrome code shouldn't see a ChromeOnly DataTransferItem"); + if (ChromeOnly()) { + aRv.Throw(NS_ERROR_DOM_SECURITY_ERR); + return nullptr; + } + + bool checkItemPrincipal = mDataTransfer->IsCrossDomainSubFrameDrop() || + (mDataTransfer->GetEventMessage() != eDrop && + mDataTransfer->GetEventMessage() != ePaste && + mDataTransfer->GetEventMessage() != eEditorInput); + + // Check if the caller is allowed to access the drag data. Callers with + // chrome privileges can always read the data. During the + // drop event, allow retrieving the data except in the case where the + // source of the drag is in a child frame of the caller. In that case, + // we only allow access to data of the same principal. During other events, + // only allow access to the data with the same principal. + // + // We don't want to fail with an exception in this siutation, rather we want + // to just pretend as though the stored data is "nullptr". This is consistent + // with Chrome's behavior and is less surprising for web applications which + // don't expect execptions to be raised when performing certain operations. + if (Principal() && checkItemPrincipal && !aPrincipal->Subsumes(Principal())) { + return nullptr; + } + + if (!variant) { + return nullptr; + } + + nsCOMPtr<nsISupports> data; + nsresult rv = variant->GetAsISupports(getter_AddRefs(data)); + if (NS_SUCCEEDED(rv) && data) { + nsCOMPtr<EventTarget> pt = do_QueryInterface(data); + if (pt) { + nsIGlobalObject* go = pt->GetOwnerGlobal(); + if (NS_WARN_IF(!go)) { + return nullptr; + } + + nsCOMPtr<nsIScriptObjectPrincipal> sp = do_QueryInterface(go); + MOZ_ASSERT(sp, "This cannot fail on the main thread."); + + nsIPrincipal* dataPrincipal = sp->GetPrincipal(); + if (NS_WARN_IF(!dataPrincipal || !aPrincipal->Equals(dataPrincipal))) { + return nullptr; + } + } + } + + return variant.forget(); +} + +} // namespace mozilla::dom |