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Diffstat (limited to 'dom/streams/Transferable.cpp')
| -rw-r--r-- | dom/streams/Transferable.cpp | 1068 |
1 files changed, 1068 insertions, 0 deletions
diff --git a/dom/streams/Transferable.cpp b/dom/streams/Transferable.cpp new file mode 100644 index 0000000000..f3e9504d86 --- /dev/null +++ b/dom/streams/Transferable.cpp @@ -0,0 +1,1068 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim:set ts=2 sw=2 sts=2 et cindent: */ +/* 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 "ErrorList.h" +#include "ReadableStreamPipeTo.h" +#include "js/RootingAPI.h" +#include "js/String.h" +#include "js/TypeDecls.h" +#include "js/Value.h" +#include "mozilla/AlreadyAddRefed.h" +#include "mozilla/dom/DOMExceptionBinding.h" +#include "nsCycleCollectionParticipant.h" +#include "nsIDOMEventListener.h" +#include "nsIGlobalObject.h" +#include "mozilla/ErrorResult.h" +#include "mozilla/ResultVariant.h" +#include "mozilla/dom/DOMException.h" +#include "mozilla/dom/MessageEvent.h" +#include "mozilla/dom/MessageChannel.h" +#include "mozilla/dom/MessagePort.h" +#include "mozilla/dom/Promise.h" +#include "mozilla/dom/Promise-inl.h" +#include "mozilla/dom/ReadableStream.h" +#include "mozilla/dom/WritableStream.h" +#include "mozilla/dom/TransformStream.h" +#include "nsISupportsImpl.h" + +namespace mozilla::dom { + +using namespace streams_abstract; + +static void PackAndPostMessage(JSContext* aCx, MessagePort* aPort, + const nsAString& aType, + JS::Handle<JS::Value> aValue, ErrorResult& aRv) { + JS::Rooted<JSObject*> obj(aCx, + JS_NewObjectWithGivenProto(aCx, nullptr, nullptr)); + if (!obj) { + // XXX: Should we crash here and there? See also bug 1762233. + JS_ClearPendingException(aCx); + aRv.Throw(NS_ERROR_UNEXPECTED); + return; + } + + JS::Rooted<JS::Value> type(aCx); + if (!xpc::NonVoidStringToJsval(aCx, aType, &type)) { + JS_ClearPendingException(aCx); + aRv.Throw(NS_ERROR_UNEXPECTED); + return; + } + if (!JS_DefineProperty(aCx, obj, "type", type, JSPROP_ENUMERATE)) { + JS_ClearPendingException(aCx); + aRv.Throw(NS_ERROR_UNEXPECTED); + return; + } + JS::Rooted<JS::Value> value(aCx, aValue); + if (!JS_WrapValue(aCx, &value)) { + JS_ClearPendingException(aCx); + aRv.Throw(NS_ERROR_UNEXPECTED); + return; + } + if (!JS_DefineProperty(aCx, obj, "value", value, JSPROP_ENUMERATE)) { + JS_ClearPendingException(aCx); + aRv.Throw(NS_ERROR_UNEXPECTED); + return; + } + + Sequence<JSObject*> transferables; // none in this case + JS::Rooted<JS::Value> objValue(aCx, JS::ObjectValue(*obj)); + aPort->PostMessage(aCx, objValue, transferables, aRv); +} + +// https://streams.spec.whatwg.org/#abstract-opdef-crossrealmtransformsenderror +static void CrossRealmTransformSendError(JSContext* aCx, MessagePort* aPort, + JS::Handle<JS::Value> aError) { + // Step 1: Perform PackAndPostMessage(port, "error", error), discarding the + // result. + PackAndPostMessage(aCx, aPort, u"error"_ns, aError, IgnoreErrors()); +} + +class SetUpTransformWritableMessageEventListener final + : public nsIDOMEventListener { + public: + SetUpTransformWritableMessageEventListener( + WritableStreamDefaultController* aController, Promise* aPromise) + : mController(aController), mBackpressurePromise(aPromise) {} + + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_CLASS(SetUpTransformWritableMessageEventListener) + + // https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformwritable + // The handler steps of Step 4. + MOZ_CAN_RUN_SCRIPT NS_IMETHOD HandleEvent(Event* aEvent) override { + AutoJSAPI jsapi; + if (!jsapi.Init(mController->GetParentObject())) { + return NS_OK; + } + JSContext* cx = jsapi.cx(); + MessageEvent* messageEvent = aEvent->AsMessageEvent(); + if (NS_WARN_IF(!messageEvent || !messageEvent->IsTrusted())) { + return NS_OK; + } + + // Step 1: Let data be the data of the message. + JS::Rooted<JS::Value> dataValue(cx); + IgnoredErrorResult rv; + messageEvent->GetData(cx, &dataValue, rv); + if (rv.Failed()) { + return NS_OK; + } + + // Step 2: Assert: Type(data) is Object. + // (But we check in runtime instead to avoid potential malicious events from + // a compromised process. Same below.) + if (NS_WARN_IF(!dataValue.isObject())) { + return NS_OK; + } + JS::Rooted<JSObject*> data(cx, &dataValue.toObject()); + + // Step 3: Let type be ! Get(data, "type"). + JS::Rooted<JS::Value> type(cx); + if (!JS_GetProperty(cx, data, "type", &type)) { + // XXX: See bug 1762233 + JS_ClearPendingException(cx); + return NS_OK; + } + + // Step 4: Let value be ! Get(data, "value"). + JS::Rooted<JS::Value> value(cx); + if (!JS_GetProperty(cx, data, "value", &value)) { + JS_ClearPendingException(cx); + return NS_OK; + } + + // Step 5: Assert: Type(type) is String. + if (NS_WARN_IF(!type.isString())) { + return NS_OK; + } + + // Step 6: If type is "pull", + bool equals = false; + if (!JS_StringEqualsLiteral(cx, type.toString(), "pull", &equals)) { + JS_ClearPendingException(cx); + return NS_OK; + } + if (equals) { + // Step 6.1: If backpressurePromise is not undefined, + MaybeResolveAndClearBackpressurePromise(); + return NS_OK; // implicit + } + + // Step 7: If type is "error", + if (!JS_StringEqualsLiteral(cx, type.toString(), "error", &equals)) { + JS_ClearPendingException(cx); + return NS_OK; + } + if (equals) { + // Step 7.1: Perform ! + // WritableStreamDefaultControllerErrorIfNeeded(controller, value). + WritableStreamDefaultControllerErrorIfNeeded(cx, mController, value, rv); + if (rv.Failed()) { + return NS_OK; + } + + // Step 7.2: If backpressurePromise is not undefined, + MaybeResolveAndClearBackpressurePromise(); + return NS_OK; // implicit + } + + // Logically it should be unreachable here, but we should expect random + // malicious messages. + NS_WARNING("Got an unexpected type other than pull/error."); + return NS_OK; + } + + void MaybeResolveAndClearBackpressurePromise() { + if (mBackpressurePromise) { + mBackpressurePromise->MaybeResolveWithUndefined(); + mBackpressurePromise = nullptr; + } + } + + // Note: This promise field is shared with the sink algorithms. + Promise* BackpressurePromise() { return mBackpressurePromise; } + + void CreateBackpressurePromise() { + mBackpressurePromise = + Promise::CreateInfallible(mController->GetParentObject()); + } + + private: + ~SetUpTransformWritableMessageEventListener() = default; + + // mController never changes before CC + // TODO: MOZ_IMMUTABLE_OUTSIDE_CC + MOZ_KNOWN_LIVE RefPtr<WritableStreamDefaultController> mController; + RefPtr<Promise> mBackpressurePromise; +}; + +NS_IMPL_CYCLE_COLLECTION(SetUpTransformWritableMessageEventListener, + mController, mBackpressurePromise) +NS_IMPL_CYCLE_COLLECTING_ADDREF(SetUpTransformWritableMessageEventListener) +NS_IMPL_CYCLE_COLLECTING_RELEASE(SetUpTransformWritableMessageEventListener) +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION( + SetUpTransformWritableMessageEventListener) + NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener) +NS_INTERFACE_MAP_END + +class SetUpTransformWritableMessageErrorEventListener final + : public nsIDOMEventListener { + public: + SetUpTransformWritableMessageErrorEventListener( + WritableStreamDefaultController* aController, MessagePort* aPort) + : mController(aController), mPort(aPort) {} + + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_CLASS( + SetUpTransformWritableMessageErrorEventListener) + + // https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformwritable + // The handler steps of Step 5. + MOZ_CAN_RUN_SCRIPT NS_IMETHOD HandleEvent(Event* aEvent) override { + auto cleanupPort = + MakeScopeExit([port = RefPtr<MessagePort>(mPort)]() { port->Close(); }); + + if (NS_WARN_IF(!aEvent->AsMessageEvent() || !aEvent->IsTrusted())) { + return NS_OK; + } + + // Step 1: Let error be a new "DataCloneError" DOMException. + RefPtr<DOMException> exception = + DOMException::Create(NS_ERROR_DOM_DATA_CLONE_ERR); + + AutoJSAPI jsapi; + if (!jsapi.Init(mPort->GetParentObject())) { + return NS_OK; + } + JSContext* cx = jsapi.cx(); + JS::Rooted<JS::Value> error(cx); + if (!ToJSValue(cx, *exception, &error)) { + return NS_OK; + } + + // Step 2: Perform ! CrossRealmTransformSendError(port, error). + CrossRealmTransformSendError(cx, mPort, error); + + // Step 3: Perform + // ! WritableStreamDefaultControllerErrorIfNeeded(controller, error). + WritableStreamDefaultControllerErrorIfNeeded(cx, mController, error, + IgnoreErrors()); + + // Step 4: Disentangle port. + // (Close() does it) + mPort->Close(); + cleanupPort.release(); + + return NS_OK; + } + + private: + ~SetUpTransformWritableMessageErrorEventListener() = default; + + // mController never changes before CC + // TODO: MOZ_IMMUTABLE_OUTSIDE_CC + MOZ_KNOWN_LIVE RefPtr<WritableStreamDefaultController> mController; + RefPtr<MessagePort> mPort; +}; + +NS_IMPL_CYCLE_COLLECTION(SetUpTransformWritableMessageErrorEventListener, + mController, mPort) +NS_IMPL_CYCLE_COLLECTING_ADDREF(SetUpTransformWritableMessageErrorEventListener) +NS_IMPL_CYCLE_COLLECTING_RELEASE( + SetUpTransformWritableMessageErrorEventListener) +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION( + SetUpTransformWritableMessageErrorEventListener) + NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener) +NS_INTERFACE_MAP_END + +// https://streams.spec.whatwg.org/#abstract-opdef-packandpostmessagehandlingerror +static bool PackAndPostMessageHandlingError( + JSContext* aCx, mozilla::dom::MessagePort* aPort, const nsAString& aType, + JS::Handle<JS::Value> aValue, JS::MutableHandle<JS::Value> aError) { + // Step 1: Let result be PackAndPostMessage(port, type, value). + ErrorResult rv; + PackAndPostMessage(aCx, aPort, aType, aValue, rv); + + // Step 2: If result is an abrupt completion, + if (rv.Failed()) { + // Step 2.2: Perform ! CrossRealmTransformSendError(port, result.[[Value]]). + MOZ_ALWAYS_TRUE(ToJSValue(aCx, std::move(rv), aError)); + CrossRealmTransformSendError(aCx, aPort, aError); + return false; + } + + // Step 3: Return result as a completion record. + return true; +} + +// https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformwritable +class CrossRealmWritableUnderlyingSinkAlgorithms final + : public UnderlyingSinkAlgorithmsBase { + public: + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED( + CrossRealmWritableUnderlyingSinkAlgorithms, UnderlyingSinkAlgorithmsBase) + + CrossRealmWritableUnderlyingSinkAlgorithms( + SetUpTransformWritableMessageEventListener* aListener, MessagePort* aPort) + : mListener(aListener), mPort(aPort) {} + + void StartCallback(JSContext* aCx, + WritableStreamDefaultController& aController, + JS::MutableHandle<JS::Value> aRetVal, + ErrorResult& aRv) override { + // Step 7. Let startAlgorithm be an algorithm that returns undefined. + aRetVal.setUndefined(); + } + + already_AddRefed<Promise> WriteCallback( + JSContext* aCx, JS::Handle<JS::Value> aChunk, + WritableStreamDefaultController& aController, ErrorResult& aRv) override { + // Step 1: If backpressurePromise is undefined, set backpressurePromise to a + // promise resolved with undefined. + // Note: This promise field is shared with the message event listener. + if (!mListener->BackpressurePromise()) { + mListener->CreateBackpressurePromise(); + mListener->BackpressurePromise()->MaybeResolveWithUndefined(); + } + + // Step 2: Return the result of reacting to backpressurePromise with the + // following fulfillment steps: + auto result = + mListener->BackpressurePromise()->ThenWithCycleCollectedArgsJS( + [](JSContext* aCx, JS::Handle<JS::Value>, ErrorResult& aRv, + SetUpTransformWritableMessageEventListener* aListener, + MessagePort* aPort, + JS::Handle<JS::Value> aChunk) -> already_AddRefed<Promise> { + // Step 2.1: Set backpressurePromise to a new promise. + aListener->CreateBackpressurePromise(); + + // Step 2.2: Let result be PackAndPostMessageHandlingError(port, + // "chunk", chunk). + JS::Rooted<JS::Value> error(aCx); + bool result = PackAndPostMessageHandlingError( + aCx, aPort, u"chunk"_ns, aChunk, &error); + + // Step 2.3: If result is an abrupt completion, + if (!result) { + // Step 2.3.1: Disentangle port. + // (Close() does it) + aPort->Close(); + + // Step 2.3.2: Return a promise rejected with result.[[Value]]. + return Promise::CreateRejected(aPort->GetParentObject(), error, + aRv); + } + + // Step 2.4: Otherwise, return a promise resolved with undefined. + return Promise::CreateResolvedWithUndefined( + aPort->GetParentObject(), aRv); + }, + std::make_tuple(mListener, mPort), std::make_tuple(aChunk)); + if (result.isErr()) { + aRv.Throw(result.unwrapErr()); + return nullptr; + } + return result.unwrap().forget(); + } + + already_AddRefed<Promise> CloseCallback(JSContext* aCx, + ErrorResult& aRv) override { + // Step 1: Perform ! PackAndPostMessage(port, "close", undefined). + PackAndPostMessage(aCx, mPort, u"close"_ns, JS::UndefinedHandleValue, aRv); + // (We'll check the result after step 2) + + // Step 2: Disentangle port. + // (Close() will do this) + mPort->Close(); + + if (aRv.Failed()) { + return nullptr; + } + + // Step 3: Return a promise resolved with undefined. + return Promise::CreateResolvedWithUndefined(mPort->GetParentObject(), aRv); + } + + already_AddRefed<Promise> AbortCallback( + JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason, + ErrorResult& aRv) override { + // Step 1: Let result be PackAndPostMessageHandlingError(port, "error", + // reason). + JS::Rooted<JS::Value> error(aCx); + bool result = PackAndPostMessageHandlingError( + aCx, mPort, u"error"_ns, + aReason.WasPassed() ? aReason.Value() : JS::UndefinedHandleValue, + &error); + + // Step 2: Disentangle port. + // (Close() will do this) + mPort->Close(); + + // Step 3: If result is an abrupt completion, return a promise rejected with + // result.[[Value]]. + if (!result) { + return Promise::CreateRejected(mPort->GetParentObject(), error, aRv); + } + + // Step 4: Otherwise, return a promise resolved with undefined. + return Promise::CreateResolvedWithUndefined(mPort->GetParentObject(), aRv); + } + + protected: + ~CrossRealmWritableUnderlyingSinkAlgorithms() override = default; + + private: + RefPtr<SetUpTransformWritableMessageEventListener> mListener; + RefPtr<MessagePort> mPort; +}; + +NS_IMPL_CYCLE_COLLECTION_INHERITED(CrossRealmWritableUnderlyingSinkAlgorithms, + UnderlyingSinkAlgorithmsBase, mListener, + mPort) +NS_IMPL_ADDREF_INHERITED(CrossRealmWritableUnderlyingSinkAlgorithms, + UnderlyingSinkAlgorithmsBase) +NS_IMPL_RELEASE_INHERITED(CrossRealmWritableUnderlyingSinkAlgorithms, + UnderlyingSinkAlgorithmsBase) +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION( + CrossRealmWritableUnderlyingSinkAlgorithms) +NS_INTERFACE_MAP_END_INHERITING(UnderlyingSinkAlgorithmsBase) + +// https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformwritable +MOZ_CAN_RUN_SCRIPT static void SetUpCrossRealmTransformWritable( + WritableStream* aWritable, MessagePort* aPort, ErrorResult& aRv) { + // (This is only needed for step 12, but let's do this early to fail early + // enough) + AutoJSAPI jsapi; + if (!jsapi.Init(aWritable->GetParentObject())) { + return; + } + JSContext* cx = jsapi.cx(); + + // Step 1: Perform ! InitializeWritableStream(stream). + // (Done by the constructor) + + // Step 2: Let controller be a new WritableStreamDefaultController. + auto controller = MakeRefPtr<WritableStreamDefaultController>( + aWritable->GetParentObject(), *aWritable); + + // Step 3: Let backpressurePromise be a new promise. + RefPtr<Promise> backpressurePromise = + Promise::CreateInfallible(aWritable->GetParentObject()); + + // Step 4: Add a handler for port’s message event with the following steps: + auto listener = MakeRefPtr<SetUpTransformWritableMessageEventListener>( + controller, backpressurePromise); + aPort->AddEventListener(u"message"_ns, listener, false); + + // Step 5: Add a handler for port’s messageerror event with the following + // steps: + auto errorListener = + MakeRefPtr<SetUpTransformWritableMessageErrorEventListener>(controller, + aPort); + aPort->AddEventListener(u"messageerror"_ns, errorListener, false); + + // Step 6: Enable port’s port message queue. + // (Start() does it) + aPort->Start(); + + // Step 7 - 10: + auto algorithms = + MakeRefPtr<CrossRealmWritableUnderlyingSinkAlgorithms>(listener, aPort); + + // Step 11: Let sizeAlgorithm be an algorithm that returns 1. + // (nullptr should serve this purpose. See also WritableStream::Constructor) + + // Step 12: Perform ! SetUpWritableStreamDefaultController(stream, controller, + // startAlgorithm, writeAlgorithm, closeAlgorithm, abortAlgorithm, 1, + // sizeAlgorithm). + SetUpWritableStreamDefaultController(cx, aWritable, controller, algorithms, 1, + /* aSizeAlgorithm */ nullptr, aRv); +} + +class SetUpTransformReadableMessageEventListener final + : public nsIDOMEventListener { + public: + SetUpTransformReadableMessageEventListener( + ReadableStreamDefaultController* aController, MessagePort* aPort) + : mController(aController), mPort(aPort) {} + + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_CLASS(SetUpTransformReadableMessageEventListener) + + // https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformreadable + // The handler steps of Step 3. + MOZ_CAN_RUN_SCRIPT NS_IMETHOD HandleEvent(Event* aEvent) override { + auto cleanupPort = + MakeScopeExit([port = RefPtr<MessagePort>(mPort)]() { port->Close(); }); + + AutoJSAPI jsapi; + if (!jsapi.Init(mPort->GetParentObject())) { + return NS_OK; + } + JSContext* cx = jsapi.cx(); + MessageEvent* messageEvent = aEvent->AsMessageEvent(); + if (NS_WARN_IF(!messageEvent || !messageEvent->IsTrusted())) { + return NS_OK; + } + + // Step 1: Let data be the data of the message. + JS::Rooted<JS::Value> dataValue(cx); + IgnoredErrorResult rv; + messageEvent->GetData(cx, &dataValue, rv); + if (rv.Failed()) { + return NS_OK; + } + + // Step 2: Assert: Type(data) is Object. + // (But we check in runtime instead to avoid potential malicious events from + // a compromised process. Same below.) + if (NS_WARN_IF(!dataValue.isObject())) { + return NS_OK; + } + JS::Rooted<JSObject*> data(cx, JS::ToObject(cx, dataValue)); + + // Step 3: Let type be ! Get(data, "type"). + JS::Rooted<JS::Value> type(cx); + if (!JS_GetProperty(cx, data, "type", &type)) { + // XXX: See bug 1762233 + JS_ClearPendingException(cx); + return NS_OK; + } + + // Step 4: Let value be ! Get(data, "value"). + JS::Rooted<JS::Value> value(cx); + if (!JS_GetProperty(cx, data, "value", &value)) { + JS_ClearPendingException(cx); + return NS_OK; + } + + // Step 5: Assert: Type(type) is String. + if (NS_WARN_IF(!type.isString())) { + return NS_OK; + } + + // Step 6: If type is "chunk", + bool equals = false; + if (!JS_StringEqualsLiteral(cx, type.toString(), "chunk", &equals)) { + JS_ClearPendingException(cx); + return NS_OK; + } + if (equals) { + // Step 6.1: Perform ! ReadableStreamDefaultControllerEnqueue(controller, + // value). + ReadableStreamDefaultControllerEnqueue(cx, mController, value, + IgnoreErrors()); + cleanupPort.release(); + return NS_OK; // implicit + } + + // Step 7: Otherwise, if type is "close", + if (!JS_StringEqualsLiteral(cx, type.toString(), "close", &equals)) { + JS_ClearPendingException(cx); + return NS_OK; + } + if (equals) { + // Step 7.1: Perform ! ReadableStreamDefaultControllerClose(controller). + ReadableStreamDefaultControllerClose(cx, mController, IgnoreErrors()); + // Step 7.2: Disentangle port. + // (Close() does it) + mPort->Close(); + cleanupPort.release(); + return NS_OK; // implicit + } + + // Step 8: Otherwise, if type is "error", + if (!JS_StringEqualsLiteral(cx, type.toString(), "error", &equals)) { + JS_ClearPendingException(cx); + return NS_OK; + } + if (equals) { + // Step 8.1: Perform ! ReadableStreamDefaultControllerError(controller, + // value). + ReadableStreamDefaultControllerError(cx, mController, value, + IgnoreErrors()); + + // Step 8.2: Disentangle port. + // (Close() does it) + mPort->Close(); + cleanupPort.release(); + return NS_OK; // implicit + } + + // Logically it should be unreachable here, but we should expect random + // malicious messages. + NS_WARNING("Got an unexpected type other than chunk/close/error."); + return NS_OK; + } + + private: + ~SetUpTransformReadableMessageEventListener() = default; + + // mController never changes before CC + // TODO: MOZ_IMMUTABLE_OUTSIDE_CC + MOZ_KNOWN_LIVE RefPtr<ReadableStreamDefaultController> mController; + RefPtr<MessagePort> mPort; +}; + +NS_IMPL_CYCLE_COLLECTION(SetUpTransformReadableMessageEventListener, + mController, mPort) +NS_IMPL_CYCLE_COLLECTING_ADDREF(SetUpTransformReadableMessageEventListener) +NS_IMPL_CYCLE_COLLECTING_RELEASE(SetUpTransformReadableMessageEventListener) +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION( + SetUpTransformReadableMessageEventListener) + NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener) +NS_INTERFACE_MAP_END + +class SetUpTransformReadableMessageErrorEventListener final + : public nsIDOMEventListener { + public: + SetUpTransformReadableMessageErrorEventListener( + ReadableStreamDefaultController* aController, MessagePort* aPort) + : mController(aController), mPort(aPort) {} + + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_CLASS( + SetUpTransformReadableMessageErrorEventListener) + + // https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformreadable + // The handler steps of Step 4. + MOZ_CAN_RUN_SCRIPT NS_IMETHOD HandleEvent(Event* aEvent) override { + auto cleanupPort = + MakeScopeExit([port = RefPtr<MessagePort>(mPort)]() { port->Close(); }); + + if (NS_WARN_IF(!aEvent->AsMessageEvent() || !aEvent->IsTrusted())) { + return NS_OK; + } + + // Step 1: Let error be a new "DataCloneError" DOMException. + RefPtr<DOMException> exception = + DOMException::Create(NS_ERROR_DOM_DATA_CLONE_ERR); + + AutoJSAPI jsapi; + if (!jsapi.Init(mPort->GetParentObject())) { + return NS_OK; + } + JSContext* cx = jsapi.cx(); + JS::Rooted<JS::Value> error(cx); + if (!ToJSValue(cx, *exception, &error)) { + return NS_OK; + } + + // Step 2: Perform ! CrossRealmTransformSendError(port, error). + CrossRealmTransformSendError(cx, mPort, error); + + // Step 3: Perform ! ReadableStreamDefaultControllerError(controller, + // error). + ReadableStreamDefaultControllerError(cx, mController, error, + IgnoreErrors()); + + // Step 4: Disentangle port. + // (Close() does it) + mPort->Close(); + cleanupPort.release(); + + return NS_OK; + } + + private: + ~SetUpTransformReadableMessageErrorEventListener() = default; + + RefPtr<ReadableStreamDefaultController> mController; + RefPtr<MessagePort> mPort; +}; + +NS_IMPL_CYCLE_COLLECTION(SetUpTransformReadableMessageErrorEventListener, + mController, mPort) +NS_IMPL_CYCLE_COLLECTING_ADDREF(SetUpTransformReadableMessageErrorEventListener) +NS_IMPL_CYCLE_COLLECTING_RELEASE( + SetUpTransformReadableMessageErrorEventListener) +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION( + SetUpTransformReadableMessageErrorEventListener) + NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener) +NS_INTERFACE_MAP_END + +// https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformreadable +class CrossRealmReadableUnderlyingSourceAlgorithms final + : public UnderlyingSourceAlgorithmsBase { + public: + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED( + CrossRealmReadableUnderlyingSourceAlgorithms, + UnderlyingSourceAlgorithmsBase) + + explicit CrossRealmReadableUnderlyingSourceAlgorithms(MessagePort* aPort) + : mPort(aPort) {} + + void StartCallback(JSContext* aCx, ReadableStreamController& aController, + JS::MutableHandle<JS::Value> aRetVal, + ErrorResult& aRv) override { + // Step 6. Let startAlgorithm be an algorithm that returns undefined. + aRetVal.setUndefined(); + } + + already_AddRefed<Promise> PullCallback(JSContext* aCx, + ReadableStreamController& aController, + ErrorResult& aRv) override { + // Step 7: Let pullAlgorithm be the following steps: + + // Step 7.1: Perform ! PackAndPostMessage(port, "pull", undefined). + PackAndPostMessage(aCx, mPort, u"pull"_ns, JS::UndefinedHandleValue, aRv); + if (aRv.Failed()) { + return nullptr; + } + + // Step 7.2: Return a promise resolved with undefined. + return Promise::CreateResolvedWithUndefined(mPort->GetParentObject(), aRv); + } + + already_AddRefed<Promise> CancelCallback( + JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason, + ErrorResult& aRv) override { + // Step 8: Let cancelAlgorithm be the following steps, taking a reason + // argument: + + // Step 8.1: Let result be PackAndPostMessageHandlingError(port, "error", + // reason). + JS::Rooted<JS::Value> error(aCx); + bool result = PackAndPostMessageHandlingError( + aCx, mPort, u"error"_ns, + aReason.WasPassed() ? aReason.Value() : JS::UndefinedHandleValue, + &error); + + // Step 8.2: Disentangle port. + // (Close() does it) + mPort->Close(); + + // Step 8.3: If result is an abrupt completion, return a promise rejected + // with result.[[Value]]. + if (!result) { + return Promise::CreateRejected(mPort->GetParentObject(), error, aRv); + } + + // Step 8.4: Otherwise, return a promise resolved with undefined. + return Promise::CreateResolvedWithUndefined(mPort->GetParentObject(), aRv); + } + + protected: + ~CrossRealmReadableUnderlyingSourceAlgorithms() override = default; + + private: + RefPtr<MessagePort> mPort; +}; + +NS_IMPL_CYCLE_COLLECTION_INHERITED(CrossRealmReadableUnderlyingSourceAlgorithms, + UnderlyingSourceAlgorithmsBase, mPort) +NS_IMPL_ADDREF_INHERITED(CrossRealmReadableUnderlyingSourceAlgorithms, + UnderlyingSourceAlgorithmsBase) +NS_IMPL_RELEASE_INHERITED(CrossRealmReadableUnderlyingSourceAlgorithms, + UnderlyingSourceAlgorithmsBase) +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION( + CrossRealmReadableUnderlyingSourceAlgorithms) +NS_INTERFACE_MAP_END_INHERITING(UnderlyingSourceAlgorithmsBase) + +// https://streams.spec.whatwg.org/#abstract-opdef-setupcrossrealmtransformreadable +MOZ_CAN_RUN_SCRIPT static void SetUpCrossRealmTransformReadable( + ReadableStream* aReadable, MessagePort* aPort, ErrorResult& aRv) { + // (This is only needed for step 10, but let's do this early to fail early + // enough) + AutoJSAPI jsapi; + if (!jsapi.Init(aReadable->GetParentObject())) { + return; + } + JSContext* cx = jsapi.cx(); + + // Step 1: Perform ! InitializeReadableStream(stream). + // (This is implicitly done by the constructor) + + // Step 2: Let controller be a new ReadableStreamDefaultController. + auto controller = + MakeRefPtr<ReadableStreamDefaultController>(aReadable->GetParentObject()); + + // Step 3: Add a handler for port’s message event with the following steps: + auto listener = + MakeRefPtr<SetUpTransformReadableMessageEventListener>(controller, aPort); + aPort->AddEventListener(u"message"_ns, listener, false); + + // Step 4: Add a handler for port’s messageerror event with the following + // steps: + auto errorListener = + MakeRefPtr<SetUpTransformReadableMessageErrorEventListener>(controller, + aPort); + aPort->AddEventListener(u"messageerror"_ns, errorListener, false); + + // Step 5: Enable port’s port message queue. + // (Start() does it) + aPort->Start(); + + // Step 6-8: + auto algorithms = + MakeRefPtr<CrossRealmReadableUnderlyingSourceAlgorithms>(aPort); + + // Step 9: Let sizeAlgorithm be an algorithm that returns 1. + // (nullptr should serve this purpose. See also ReadableStream::Constructor) + + // Step 10: Perform ! SetUpReadableStreamDefaultController(stream, controller, + // startAlgorithm, pullAlgorithm, cancelAlgorithm, 0, sizeAlgorithm). + SetUpReadableStreamDefaultController(cx, aReadable, controller, algorithms, 0, + /* aSizeAlgorithm */ nullptr, aRv); +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-steps +bool ReadableStream::Transfer(JSContext* aCx, UniqueMessagePortId& aPortId) { + // Step 1: If ! IsReadableStreamLocked(value) is true, throw a + // "DataCloneError" DOMException. + // (Implemented in StructuredCloneHolder::CustomCanTransferHandler, but double + // check here as the state might have changed in case this ReadableStream is + // created by a TransferStream and being transferred together with the + // parent.) + if (IsReadableStreamLocked(this)) { + return false; + } + + // Step 2: Let port1 be a new MessagePort in the current Realm. + // Step 3: Let port2 be a new MessagePort in the current Realm. + // Step 4: Entangle port1 and port2. + // (The MessageChannel constructor does exactly that.) + // https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messagechannel + ErrorResult rv; + RefPtr<dom::MessageChannel> channel = + dom::MessageChannel::Constructor(mGlobal, rv); + if (rv.MaybeSetPendingException(aCx)) { + return false; + } + + // Step 5: Let writable be a new WritableStream in the current Realm. + RefPtr<WritableStream> writable = new WritableStream( + mGlobal, WritableStream::HoldDropJSObjectsCaller::Implicit); + + // Step 6: Perform ! SetUpCrossRealmTransformWritable(writable, port1). + // MOZ_KnownLive because Port1 never changes before CC + SetUpCrossRealmTransformWritable(writable, MOZ_KnownLive(channel->Port1()), + rv); + if (rv.MaybeSetPendingException(aCx)) { + return false; + } + + // Step 7: Let promise be ! ReadableStreamPipeTo(value, writable, false, + // false, false). + RefPtr<Promise> promise = + ReadableStreamPipeTo(this, writable, false, false, false, nullptr, rv); + if (rv.MaybeSetPendingException(aCx)) { + return false; + } + + // Step 8: Set promise.[[PromiseIsHandled]] to true. + MOZ_ALWAYS_TRUE(promise->SetAnyPromiseIsHandled()); + + // Step 9: Set dataHolder.[[port]] to ! StructuredSerializeWithTransfer(port2, + // « port2 »). + channel->Port2()->CloneAndDisentangle(aPortId); + + return true; +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-receiving-steps +MOZ_CAN_RUN_SCRIPT already_AddRefed<ReadableStream> +ReadableStream::ReceiveTransferImpl(JSContext* aCx, nsIGlobalObject* aGlobal, + MessagePort& aPort) { + // Step 1: Let deserializedRecord be + // ! StructuredDeserializeWithTransfer(dataHolder.[[port]], the current + // Realm). + // Step 2: Let port be deserializedRecord.[[Deserialized]]. + + // Step 3: Perform ! SetUpCrossRealmTransformReadable(value, port). + RefPtr<ReadableStream> readable = + new ReadableStream(aGlobal, HoldDropJSObjectsCaller::Implicit); + ErrorResult rv; + SetUpCrossRealmTransformReadable(readable, &aPort, rv); + if (rv.MaybeSetPendingException(aCx)) { + return nullptr; + } + return readable.forget(); +} + +bool ReadableStream::ReceiveTransfer( + JSContext* aCx, nsIGlobalObject* aGlobal, MessagePort& aPort, + JS::MutableHandle<JSObject*> aReturnObject) { + RefPtr<ReadableStream> readable = + ReadableStream::ReceiveTransferImpl(aCx, aGlobal, aPort); + if (!readable) { + return false; + } + + JS::Rooted<JS::Value> value(aCx); + if (!GetOrCreateDOMReflector(aCx, readable, &value)) { + JS_ClearPendingException(aCx); + return false; + } + aReturnObject.set(&value.toObject()); + + return true; +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-steps① +bool WritableStream::Transfer(JSContext* aCx, UniqueMessagePortId& aPortId) { + // Step 1: If ! IsWritableStreamLocked(value) is true, throw a + // "DataCloneError" DOMException. + // (Implemented in StructuredCloneHolder::CustomCanTransferHandler, but double + // check here as the state might have changed in case this WritableStream is + // created by a TransferStream and being transferred together with the + // parent.) + if (IsWritableStreamLocked(this)) { + return false; + } + + // Step 2: Let port1 be a new MessagePort in the current Realm. + // Step 3: Let port2 be a new MessagePort in the current Realm. + // Step 4: Entangle port1 and port2. + // (The MessageChannel constructor does exactly that.) + // https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messagechannel + ErrorResult rv; + RefPtr<dom::MessageChannel> channel = + dom::MessageChannel::Constructor(mGlobal, rv); + if (rv.MaybeSetPendingException(aCx)) { + return false; + } + + // Step 5: Let readable be a new ReadableStream in the current Realm. + RefPtr<ReadableStream> readable = new ReadableStream( + mGlobal, ReadableStream::HoldDropJSObjectsCaller::Implicit); + + // Step 6: Perform ! SetUpCrossRealmTransformReadable(readable, port1). + // MOZ_KnownLive because Port1 never changes before CC + SetUpCrossRealmTransformReadable(readable, MOZ_KnownLive(channel->Port1()), + rv); + if (rv.MaybeSetPendingException(aCx)) { + return false; + } + + // Step 7: Let promise be ! ReadableStreamPipeTo(readable, value, false, + // false, false). + RefPtr<Promise> promise = + ReadableStreamPipeTo(readable, this, false, false, false, nullptr, rv); + if (rv.Failed()) { + return false; + } + + // Step 8: Set promise.[[PromiseIsHandled]] to true. + MOZ_ALWAYS_TRUE(promise->SetAnyPromiseIsHandled()); + + // Step 9: Set dataHolder.[[port]] to ! StructuredSerializeWithTransfer(port2, + // « port2 »). + channel->Port2()->CloneAndDisentangle(aPortId); + + return true; +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-receiving-steps① +MOZ_CAN_RUN_SCRIPT already_AddRefed<WritableStream> +WritableStream::ReceiveTransferImpl(JSContext* aCx, nsIGlobalObject* aGlobal, + MessagePort& aPort) { + // Step 1: Let deserializedRecord be ! + // StructuredDeserializeWithTransfer(dataHolder.[[port]], the current Realm). + // Step 2: Let port be a deserializedRecord.[[Deserialized]]. + + // Step 3: Perform ! SetUpCrossRealmTransformWritable(value, port). + RefPtr<WritableStream> writable = new WritableStream( + aGlobal, WritableStream::HoldDropJSObjectsCaller::Implicit); + ErrorResult rv; + SetUpCrossRealmTransformWritable(writable, &aPort, rv); + if (rv.MaybeSetPendingException(aCx)) { + return nullptr; + } + return writable.forget(); +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-receiving-steps① +bool WritableStream::ReceiveTransfer( + JSContext* aCx, nsIGlobalObject* aGlobal, MessagePort& aPort, + JS::MutableHandle<JSObject*> aReturnObject) { + RefPtr<WritableStream> writable = + WritableStream::ReceiveTransferImpl(aCx, aGlobal, aPort); + if (!writable) { + return false; + } + + JS::Rooted<JS::Value> value(aCx); + if (!GetOrCreateDOMReflector(aCx, writable, &value)) { + JS_ClearPendingException(aCx); + return false; + } + aReturnObject.set(&value.toObject()); + + return true; +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-steps② +bool TransformStream::Transfer(JSContext* aCx, UniqueMessagePortId& aPortId1, + UniqueMessagePortId& aPortId2) { + // Step 1: Let readable be value.[[readable]]. + // Step 2: Let writable be value.[[writable]]. + // Step 3: If ! IsReadableStreamLocked(readable) is true, throw a + // "DataCloneError" DOMException. + // Step 4: If ! IsWritableStreamLocked(writable) is true, throw a + // "DataCloneError" DOMException. + // (Implemented in StructuredCloneHolder::CustomCanTransferHandler, but double + // check here as the state might have changed by + // Readable/WritableStream::Transfer in case the stream members of this + // TransformStream are being transferred together.) + if (IsReadableStreamLocked(mReadable) || IsWritableStreamLocked(mWritable)) { + return false; + } + + // Step 5: Set dataHolder.[[readable]] to ! + // StructuredSerializeWithTransfer(readable, « readable »). + // TODO: Mark mReadable as MOZ_KNOWN_LIVE again (bug 1769854) + if (!MOZ_KnownLive(mReadable)->Transfer(aCx, aPortId1)) { + return false; + } + + // Step 6: Set dataHolder.[[writable]] to ! + // StructuredSerializeWithTransfer(writable, « writable »). + // TODO: Mark mReadable as MOZ_KNOWN_LIVE again (bug 1769854) + return MOZ_KnownLive(mWritable)->Transfer(aCx, aPortId2); +} + +// https://streams.spec.whatwg.org/#ref-for-transfer-receiving-steps② +bool TransformStream::ReceiveTransfer( + JSContext* aCx, nsIGlobalObject* aGlobal, MessagePort& aPort1, + MessagePort& aPort2, JS::MutableHandle<JSObject*> aReturnObject) { + // Step 1: Let readableRecord be ! + // StructuredDeserializeWithTransfer(dataHolder.[[readable]], the current + // Realm). + RefPtr<ReadableStream> readable = + ReadableStream::ReceiveTransferImpl(aCx, aGlobal, aPort1); + if (!readable) { + return false; + } + + // Step 2: Let writableRecord be ! + // StructuredDeserializeWithTransfer(dataHolder.[[writable]], the current + // Realm). + RefPtr<WritableStream> writable = + WritableStream::ReceiveTransferImpl(aCx, aGlobal, aPort2); + if (!writable) { + return false; + } + + // Step 3: Set value.[[readable]] to readableRecord.[[Deserialized]]. + // Step 4: Set value.[[writable]] to writableRecord.[[Deserialized]]. + // Step 5: Set value.[[backpressure]], value.[[backpressureChangePromise]], + // and value.[[controller]] to undefined. + RefPtr<TransformStream> stream = + new TransformStream(aGlobal, readable, writable); + JS::Rooted<JS::Value> value(aCx); + if (!GetOrCreateDOMReflector(aCx, stream, &value)) { + JS_ClearPendingException(aCx); + return false; + } + aReturnObject.set(&value.toObject()); + + return true; +} + +} // namespace mozilla::dom |