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/* -*- 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
#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_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