tubestation/dom/serviceworkers/ServiceWorker.cpp

/* -*- 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 "ServiceWorker.h"

#include "mozilla/dom/Document.h"
#include "nsGlobalWindowInner.h"
#include "nsPIDOMWindow.h"
#include "ServiceWorkerChild.h"
#include "ServiceWorkerCloneData.h"
#include "ServiceWorkerManager.h"
#include "ServiceWorkerPrivate.h"
#include "ServiceWorkerRegistration.h"
#include "ServiceWorkerUtils.h"

#include "mozilla/dom/ClientIPCTypes.h"
#include "mozilla/dom/ClientState.h"
#include "mozilla/dom/MessagePortBinding.h"
#include "mozilla/dom/Navigator.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/ServiceWorkerGlobalScopeBinding.h"
#include "mozilla/dom/WorkerPrivate.h"
#include "mozilla/ipc/BackgroundChild.h"
#include "mozilla/ipc/PBackgroundChild.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/StorageAccess.h"

#ifdef XP_WIN
#  undef PostMessage
#endif

using mozilla::ipc::BackgroundChild;
using mozilla::ipc::PBackgroundChild;

namespace mozilla::dom {

// static
already_AddRefed<ServiceWorker> ServiceWorker::Create(
    nsIGlobalObject* aOwner, const ServiceWorkerDescriptor& aDescriptor) {
  RefPtr<ServiceWorker> ref = new ServiceWorker(aOwner, aDescriptor);
  return ref.forget();
}

ServiceWorker::ServiceWorker(nsIGlobalObject* aGlobal,
                             const ServiceWorkerDescriptor& aDescriptor)
    : DOMEventTargetHelper(aGlobal),
      mDescriptor(aDescriptor),
      mShutdown(false),
      mLastNotifiedState(ServiceWorkerState::Installing) {
  MOZ_DIAGNOSTIC_ASSERT(aGlobal);

  PBackgroundChild* parentActor =
      BackgroundChild::GetOrCreateForCurrentThread();
  if (NS_WARN_IF(!parentActor)) {
    Shutdown();
    return;
  }

  RefPtr<ServiceWorkerChild> actor = ServiceWorkerChild::Create();
  if (NS_WARN_IF(!actor)) {
    Shutdown();
    return;
  }

  PServiceWorkerChild* sentActor =
      parentActor->SendPServiceWorkerConstructor(actor, aDescriptor.ToIPC());
  if (NS_WARN_IF(!sentActor)) {
    Shutdown();
    return;
  }
  MOZ_DIAGNOSTIC_ASSERT(sentActor == actor);

  mActor = std::move(actor);
  mActor->SetOwner(this);

  KeepAliveIfHasListenersFor(nsGkAtoms::onstatechange);

  // The error event handler is required by the spec currently, but is not used
  // anywhere.  Don't keep the object alive in that case.

  // Attempt to get an existing binding object for the registration
  // associated with this ServiceWorker.
  RefPtr<ServiceWorkerRegistration> reg =
      aGlobal->GetServiceWorkerRegistration(ServiceWorkerRegistrationDescriptor(
          mDescriptor.RegistrationId(), mDescriptor.RegistrationVersion(),
          mDescriptor.PrincipalInfo(), mDescriptor.Scope(),
          ServiceWorkerUpdateViaCache::Imports));

  if (reg) {
    MaybeAttachToRegistration(reg);
    // Following codes are commented since GetRegistration has no
    // implementation. If we can not get an existing binding object, probably
    // need to create one to associate to it.
    // https://bugzilla.mozilla.org/show_bug.cgi?id=1769652
    /*
    } else {

      RefPtr<ServiceWorker> self = this;
      GetRegistration(
          [self = std::move(self)](
              const ServiceWorkerRegistrationDescriptor& aDescriptor) {
            nsIGlobalObject* global = self->GetParentObject();
            NS_ENSURE_TRUE_VOID(global);
            RefPtr<ServiceWorkerRegistration> reg =
                global->GetOrCreateServiceWorkerRegistration(aDescriptor);
            self->MaybeAttachToRegistration(reg);
          },
          [](ErrorResult&& aRv) {
            // do nothing
            aRv.SuppressException();
          });
    */
  }
}

ServiceWorker::~ServiceWorker() { Shutdown(); }

NS_IMPL_CYCLE_COLLECTION_INHERITED(ServiceWorker, DOMEventTargetHelper,
                                   mRegistration);

NS_IMPL_ADDREF_INHERITED(ServiceWorker, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(ServiceWorker, DOMEventTargetHelper)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ServiceWorker)
  NS_INTERFACE_MAP_ENTRY_CONCRETE(ServiceWorker)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

JSObject* ServiceWorker::WrapObject(JSContext* aCx,
                                    JS::Handle<JSObject*> aGivenProto) {
  return ServiceWorker_Binding::Wrap(aCx, this, aGivenProto);
}

ServiceWorkerState ServiceWorker::State() const { return mDescriptor.State(); }

void ServiceWorker::SetState(ServiceWorkerState aState) {
  NS_ENSURE_TRUE_VOID(aState >= mDescriptor.State());
  mDescriptor.SetState(aState);
}

void ServiceWorker::MaybeDispatchStateChangeEvent() {
  if (mDescriptor.State() <= mLastNotifiedState || !GetParentObject()) {
    return;
  }
  mLastNotifiedState = mDescriptor.State();

  DOMEventTargetHelper::DispatchTrustedEvent(u"statechange"_ns);

  // Once we have transitioned to the redundant state then no
  // more statechange events will occur.  We can allow the DOM
  // object to GC if script is not holding it alive.
  if (mLastNotifiedState == ServiceWorkerState::Redundant) {
    IgnoreKeepAliveIfHasListenersFor(nsGkAtoms::onstatechange);
  }
}

void ServiceWorker::GetScriptURL(nsString& aURL) const {
  CopyUTF8toUTF16(mDescriptor.ScriptURL(), aURL);
}

void ServiceWorker::PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
                                const Sequence<JSObject*>& aTransferable,
                                ErrorResult& aRv) {
  // Step 6.1 of
  // https://w3c.github.io/ServiceWorker/#service-worker-postmessage-options
  // invokes
  // https://w3c.github.io/ServiceWorker/#run-service-worker
  // which returns failure in step 3 if the ServiceWorker state is redundant.
  // This will result in the "in parallel" step 6.1 of postMessage itself early
  // returning without starting the ServiceWorker and without throwing an error.
  if (State() == ServiceWorkerState::Redundant) {
    return;
  }

  nsIGlobalObject* global = GetOwnerGlobal();
  if (NS_WARN_IF(!global)) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  Maybe<ClientInfo> clientInfo = global->GetClientInfo();
  Maybe<ClientState> clientState = global->GetClientState();
  if (NS_WARN_IF(clientInfo.isNothing() || clientState.isNothing())) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  auto storageAllowed = clientState.ref().GetStorageAccess();
  // This check should be removed as part of bug 1776271 when we should be able
  // to have a stronger invariant about how content should not be able to see
  // a ServiceWorker instance if there is no access to storage.  For now we
  // retain this check as a defense-in-depth mechanism at runtime and a
  // non-diagnostic assert for test purposes.
  MOZ_ASSERT(storageAllowed != StorageAccess::eDeny);
  if (storageAllowed == StorageAccess::eDeny) {
    ServiceWorkerManager::LocalizeAndReportToAllClients(
        mDescriptor.Scope(), "ServiceWorkerPostMessageStorageError",
        nsTArray<nsString>{NS_ConvertUTF8toUTF16(mDescriptor.Scope())});
    aRv.Throw(NS_ERROR_DOM_SECURITY_ERR);
    return;
  }

  JS::Rooted<JS::Value> transferable(aCx, JS::UndefinedValue());
  aRv = nsContentUtils::CreateJSValueFromSequenceOfObject(aCx, aTransferable,
                                                          &transferable);
  if (aRv.Failed()) {
    return;
  }

  // Window-to-SW messages do not allow memory sharing since they are not in the
  // same agent cluster group, but we do not want to throw an error during the
  // serialization. Because of this, ServiceWorkerCloneData will propagate an
  // error message data if the SameProcess serialization is required. So that
  // the receiver (service worker) knows that it needs to throw while
  // deserialization and sharing memory objects are not propagated to the other
  // process.
  JS::CloneDataPolicy clonePolicy;
  if (global->IsSharedMemoryAllowed()) {
    clonePolicy.allowSharedMemoryObjects();
  }

  RefPtr<ServiceWorkerCloneData> data = new ServiceWorkerCloneData();
  data->Write(aCx, aMessage, transferable, clonePolicy, aRv);
  if (aRv.Failed()) {
    return;
  }

  // The value of CloneScope() is set while StructuredCloneData::Write(). If the
  // aValue contains a shared memory object, then the scope will be restricted
  // and thus return SameProcess. If not, it will return DifferentProcess.
  //
  // We know that an attempt to postMessage a shared memory object will result
  // in an error if the source and target aren't in the same agent cluster and
  // ServiceWorkers are inherently in a different agent cluster from windows,
  // so convert to an error if this binding is attached to a window (which must
  // be the case if this is the main thread).
  if (data->CloneScope() ==
          StructuredCloneHolder::StructuredCloneScope::SameProcess &&
      NS_IsMainThread()) {
    data->SetAsErrorMessageData();
  }

  if (!mActor) {
    return;
  }

  ClonedOrErrorMessageData clonedData;
  if (!data->BuildClonedMessageData(clonedData)) {
    return;
  }

  mActor->SendPostMessage(
      clonedData,
      ClientInfoAndState(clientInfo.ref().ToIPC(), clientState.ref().ToIPC()));
}

void ServiceWorker::PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
                                const StructuredSerializeOptions& aOptions,
                                ErrorResult& aRv) {
  PostMessage(aCx, aMessage, aOptions.mTransfer, aRv);
}

const ServiceWorkerDescriptor& ServiceWorker::Descriptor() const {
  return mDescriptor;
}

void ServiceWorker::DisconnectFromOwner() {
  DOMEventTargetHelper::DisconnectFromOwner();
}

void ServiceWorker::RevokeActor(ServiceWorkerChild* aActor) {
  MOZ_DIAGNOSTIC_ASSERT(mActor);
  MOZ_DIAGNOSTIC_ASSERT(mActor == aActor);
  mActor->RevokeOwner(this);
  mActor = nullptr;

  mShutdown = true;
}

void ServiceWorker::MaybeAttachToRegistration(
    ServiceWorkerRegistration* aRegistration) {
  MOZ_DIAGNOSTIC_ASSERT(aRegistration);
  MOZ_DIAGNOSTIC_ASSERT(!mRegistration);

  // If the registration no longer actually references this ServiceWorker
  // then we must be in the redundant state.
  if (!aRegistration->Descriptor().HasWorker(mDescriptor)) {
    SetState(ServiceWorkerState::Redundant);
    MaybeDispatchStateChangeEvent();
    return;
  }

  mRegistration = aRegistration;
}

void ServiceWorker::Shutdown() {
  if (mShutdown) {
    return;
  }
  mShutdown = true;

  if (mActor) {
    mActor->RevokeOwner(this);
    mActor->MaybeStartTeardown();
    mActor = nullptr;
  }
}

}  // namespace mozilla::dom