namespace dom {

static bool
ShouldExposeChildWindow(nsString& aNameBeingResolved, nsPIDOMWindowOuter* aChild)
{
  Element* e = aChild->GetFrameElementInternal();
  if (e && e->IsInShadowTree()) {
    return false;
  }

  // If we're same-origin with the child, go ahead and expose it.
  nsCOMPtr<nsIScriptObjectPrincipal> sop = do_QueryInterface(aChild);
  NS_ENSURE_TRUE(sop, false);
  if (nsContentUtils::SubjectPrincipal()->Equals(sop->GetPrincipal())) {
    return true;
  }

  // If we're not same-origin, expose it _only_ if the name of the browsing
  // context matches the 'name' attribute of the frame element in the parent.
  // The motivations behind this heuristic are worth explaining here.
  //
  // Historically, all UAs supported global named access to any child browsing
  // context (that is to say, window.dolske returns a child frame where either
  // the "name" attribute on the frame element was set to "dolske", or where
  // the child explicitly set window.name = "dolske").
  //
  // This is problematic because it allows possibly-malicious and unrelated
  // cross-origin subframes to pollute the global namespace of their parent in
  // unpredictable ways (see bug 860494). This is also problematic for browser
  // engines like Servo that want to run cross-origin script on different
  // threads.
  //
  // The naive solution here would be to filter out any cross-origin subframes
  // obtained when doing named lookup in global scope. But that is unlikely to
  // be web-compatible, since it will break named access for consumers that do
  // <iframe name="dolske" src="http://cross-origin.com/sadtrombone.html"> and
  // expect to be able to access the cross-origin subframe via named lookup on
  // the global.
  //
  // The optimal behavior would be to do the following:
  // (a) Look for any child browsing context with name="dolske".
  // (b) If the result is cross-origin, null it out.
  // (c) If we have null, look for a frame element whose 'name' attribute is
  //     "dolske".
  //
  // Unfortunately, (c) would require some engineering effort to be performant
  // in Gecko, and probably in other UAs as well. So we go with a simpler
  // approximation of the above. This approximation will only break sites that
  // rely on their cross-origin subframes setting window.name to a known value,
  // which is unlikely to be very common. And while it does introduce a
  // dependency on cross-origin state when doing global lookups, it doesn't
  // allow the child to arbitrarily pollute the parent namespace, and requires
  // cross-origin communication only in a limited set of cases that can be
  // computed independently by the parent.
  return e && e->AttrValueIs(kNameSpaceID_None, nsGkAtoms::name,
                             aNameBeingResolved, eCaseMatters);
}

bool
WindowNamedPropertiesHandler::getOwnPropDescriptor(JSContext* aCx,
                                                   JS::Handle<JSObject*> aProxy,
                                                   JS::Handle<jsid> aId,
                                                   bool /* unused */,
                                                   JS::MutableHandle<JS::PropertyDescriptor> aDesc)
                                                   const
{
  if (!JSID_IS_STRING(aId)) {
    // Nothing to do if we're resolving a non-string property.
    return true;
  }

  bool hasOnPrototype;
  if (!HasPropertyOnPrototype(aCx, aProxy, aId, &hasOnPrototype)) {
    return false;
  }
  if (hasOnPrototype) {
    return true;
  }

  nsAutoJSString str;
  if (!str.init(aCx, JSID_TO_STRING(aId))) {
    return false;
  }

  if(str.IsEmpty()) {
    return true;
  }

  // Grab the DOM window.
  JS::Rooted<JSObject*> global(aCx, JS_GetGlobalForObject(aCx, aProxy));
  nsGlobalWindow* win = xpc::WindowOrNull(global);
  if (win->Length() > 0) {
    nsCOMPtr<nsPIDOMWindowOuter> childWin = win->GetChildWindow(str);
    if (childWin && ShouldExposeChildWindow(str, childWin)) {
      // We found a subframe of the right name. Shadowing via |var foo| in
      // global scope is still allowed, since |var| only looks up |own|
      // properties. But unqualified shadowing will fail, per-spec.
      JS::Rooted<JS::Value> v(aCx);
      if (!WrapObject(aCx, childWin, &v)) {
        return false;
      }
      FillPropertyDescriptor(aDesc, aProxy, 0, v);
      return true;
    }
  }

  // The rest of this function is for HTML documents only.
  nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(win->GetExtantDoc());
  if (!htmlDoc) {
    return true;
  }
  nsHTMLDocument* document = static_cast<nsHTMLDocument*>(htmlDoc.get());

  Element* element = document->GetElementById(str);
  if (element) {
    JS::Rooted<JS::Value> v(aCx);
    if (!WrapObject(aCx, element, &v)) {
      return false;
    }
    FillPropertyDescriptor(aDesc, aProxy, 0, v);
    return true;
  }

  nsWrapperCache* cache;
  nsISupports* result = document->ResolveName(str, &cache);
  if (!result) {
    return true;
  }

  JS::Rooted<JS::Value> v(aCx);
  if (!WrapObject(aCx, result, cache, nullptr, &v)) {
    return false;
  }
  FillPropertyDescriptor(aDesc, aProxy, 0, v);
  return true;
}

bool
WindowNamedPropertiesHandler::defineProperty(JSContext* aCx,
                                             JS::Handle<JSObject*> aProxy,
                                             JS::Handle<jsid> aId,
                                             JS::Handle<JS::PropertyDescriptor> aDesc,
                                             JS::ObjectOpResult &result) const
{
  ErrorResult rv;
  rv.ThrowTypeError<MSG_DEFINEPROPERTY_ON_GSP>();
  rv.MaybeSetPendingException(aCx);
  return false;
}

bool
WindowNamedPropertiesHandler::ownPropNames(JSContext* aCx,
                                           JS::Handle<JSObject*> aProxy,
                                           unsigned flags,
                                           JS::AutoIdVector& aProps) const
{
  if (!(flags & JSITER_HIDDEN)) {
    // None of our named properties are enumerable.
    return true;
  }

  // Grab the DOM window.
  nsGlobalWindow* win = xpc::WindowOrNull(JS_GetGlobalForObject(aCx, aProxy));
  nsTArray<nsString> names;
  // The names live on the outer window, which might be null
  nsGlobalWindow* outer = win->GetOuterWindowInternal();
  if (outer) {
    nsDOMWindowList* childWindows = outer->GetWindowList();
    if (childWindows) {
      uint32_t length = childWindows->GetLength();
      for (uint32_t i = 0; i < length; ++i) {
        nsCOMPtr<nsIDocShellTreeItem> item =
          childWindows->GetDocShellTreeItemAt(i);
        // This is a bit silly, since we could presumably just do
        // item->GetWindow().  But it's not obvious whether this does the same
        // thing as GetChildWindow() with the item's name (due to the complexity
        // of FindChildWithName).  Since GetChildWindow is what we use in
        // getOwnPropDescriptor, let's try to be consistent.
        nsString name;
        item->GetName(name);
        if (!names.Contains(name)) {
          // Make sure we really would expose it from getOwnPropDescriptor.
          nsCOMPtr<nsPIDOMWindowOuter> childWin = win->GetChildWindow(name);
          if (childWin && ShouldExposeChildWindow(name, childWin)) {
            names.AppendElement(name);
          }
        }
      }
    }
  }
  if (!AppendNamedPropertyIds(aCx, aProxy, names, false, aProps)) {
    return false;
  }

  names.Clear();
  nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(win->GetExtantDoc());
  if (!htmlDoc) {
    return true;
  }
  nsHTMLDocument* document = static_cast<nsHTMLDocument*>(htmlDoc.get());
  // Document names are enumerable, so we want to get them no matter what flags
  // is.
  document->GetSupportedNames(names);

  JS::AutoIdVector docProps(aCx);
  if (!AppendNamedPropertyIds(aCx, aProxy, names, false, docProps)) {
    return false;
  }

  return js::AppendUnique(aCx, aProps, docProps);
}

bool
WindowNamedPropertiesHandler::delete_(JSContext* aCx,
                                      JS::Handle<JSObject*> aProxy,
                                      JS::Handle<jsid> aId,
                                      JS::ObjectOpResult &aResult) const
{
  return aResult.failCantDeleteWindowNamedProperty();
}

static bool
ResolveWindowNamedProperty(JSContext* aCx, JS::Handle<JSObject*> aWrapper,
                           JS::Handle<JSObject*> aObj, JS::Handle<jsid> aId,
                           JS::MutableHandle<JS::PropertyDescriptor> aDesc)
{
  {
    JSAutoCompartment ac(aCx, aObj);
    if (!js::GetProxyHandler(aObj)->getOwnPropertyDescriptor(aCx, aObj, aId,
                                                             aDesc)) {
      return false;
    }
  }

  if (aDesc.object()) {
    aDesc.object().set(aWrapper);

    return JS_WrapPropertyDescriptor(aCx, aDesc);
  }

  return true;
}

static bool
EnumerateWindowNamedProperties(JSContext* aCx, JS::Handle<JSObject*> aWrapper,
                               JS::Handle<JSObject*> aObj,
                               JS::AutoIdVector& aProps)
{
  JSAutoCompartment ac(aCx, aObj);
  return js::GetProxyHandler(aObj)->ownPropertyKeys(aCx, aObj, aProps);
}

const NativePropertyHooks sWindowNamedPropertiesNativePropertyHooks[] = { {
  ResolveWindowNamedProperty,
  EnumerateWindowNamedProperties,
  nullptr,
  { nullptr, nullptr },
  prototypes::id::_ID_Count,
  constructors::id::_ID_Count,
  nullptr
} };

static const DOMIfaceAndProtoJSClass WindowNamedPropertiesClass = {
  PROXY_CLASS_DEF("WindowProperties",
                  JSCLASS_IS_DOMIFACEANDPROTOJSCLASS),
  eNamedPropertiesObject,
  false,
  prototypes::id::_ID_Count,
  0,
  sWindowNamedPropertiesNativePropertyHooks,
  "[object WindowProperties]",
  EventTargetBinding::GetProtoObject
};

// static
JSObject*
WindowNamedPropertiesHandler::Create(JSContext* aCx,
                                     JS::Handle<JSObject*> aProto)
{
  // Note: since the scope polluter proxy lives on the window's prototype
  // chain, it needs a singleton type to avoid polluting type information
  // for properties on the window.
  js::ProxyOptions options;
  options.setSingleton(true);
  options.setClass(&WindowNamedPropertiesClass.mBase);

  JS::Rooted<JSObject*> gsp(aCx);
  gsp = js::NewProxyObject(aCx, WindowNamedPropertiesHandler::getInstance(),
                           JS::NullHandleValue, aProto,
                           options);
  if (!gsp) {
    return nullptr;
  }

  bool succeeded;
  if (!JS_SetImmutablePrototype(aCx, gsp, &succeeded)) {
    return nullptr;
  }
  MOZ_ASSERT(succeeded,
             "errors making the [[Prototype]] of the named properties object "
             "immutable should have been JSAPI failures, not !succeeded");

  return gsp;
}

} // namespace dom
Exemplo n.º 2
0
                    nsCycleCollectionTraversalCallback& aCb) const override {
    auto location =
        static_cast<BrowsingContext::LocationProxy*>(GetNative(aProxy));
    CycleCollectionNoteChild(aCb, location->GetBrowsingContext(),
                             "js::GetObjectPrivate(obj)->GetBrowsingContext()");
  }
};

static const RemoteLocationProxy sSingleton;

// Give RemoteLocationProxy 2 reserved slots, like the other wrappers,
// so JSObject::swap can swap it with CrossCompartmentWrappers without requiring
// malloc.
template <>
const js::Class RemoteLocationProxy::Base::sClass =
    PROXY_CLASS_DEF("Proxy", JSCLASS_HAS_RESERVED_SLOTS(2));

void BrowsingContext::Location(JSContext* aCx,
                               JS::MutableHandle<JSObject*> aLocation,
                               ErrorResult& aError) {
  aError.MightThrowJSException();
  sSingleton.GetProxyObject(aCx, &mLocation, aLocation);
  if (!aLocation) {
    aError.StealExceptionFromJSContext(aCx);
  }
}

void BrowsingContext::Close(CallerType aCallerType, ErrorResult& aError) {
  // FIXME We need to set mClosed, but only once we're sending the
  //       DOMWindowClose event (which happens in the process where the
  //       document for this browsing context is loaded).
namespace dom {

static bool
ShouldExposeChildWindow(nsString& aNameBeingResolved, nsIDOMWindow *aChild)
{
    // If we're same-origin with the child, go ahead and expose it.
    nsCOMPtr<nsIScriptObjectPrincipal> sop = do_QueryInterface(aChild);
    NS_ENSURE_TRUE(sop, false);
    if (nsContentUtils::SubjectPrincipal()->Equals(sop->GetPrincipal())) {
        return true;
    }

    // If we're not same-origin, expose it _only_ if the name of the browsing
    // context matches the 'name' attribute of the frame element in the parent.
    // The motivations behind this heuristic are worth explaining here.
    //
    // Historically, all UAs supported global named access to any child browsing
    // context (that is to say, window.dolske returns a child frame where either
    // the "name" attribute on the frame element was set to "dolske", or where
    // the child explicitly set window.name = "dolske").
    //
    // This is problematic because it allows possibly-malicious and unrelated
    // cross-origin subframes to pollute the global namespace of their parent in
    // unpredictable ways (see bug 860494). This is also problematic for browser
    // engines like Servo that want to run cross-origin script on different
    // threads.
    //
    // The naive solution here would be to filter out any cross-origin subframes
    // obtained when doing named lookup in global scope. But that is unlikely to
    // be web-compatible, since it will break named access for consumers that do
    // <iframe name="dolske" src="http://cross-origin.com/sadtrombone.html"> and
    // expect to be able to access the cross-origin subframe via named lookup on
    // the global.
    //
    // The optimal behavior would be to do the following:
    // (a) Look for any child browsing context with name="dolske".
    // (b) If the result is cross-origin, null it out.
    // (c) If we have null, look for a frame element whose 'name' attribute is
    //     "dolske".
    //
    // Unfortunately, (c) would require some engineering effort to be performant
    // in Goanna, and probably in other UAs as well. So we go with a simpler
    // approximation of the above. This approximation will only break sites that
    // rely on their cross-origin subframes setting window.name to a known value,
    // which is unlikely to be very common. And while it does introduce a
    // dependency on cross-origin state when doing global lookups, it doesn't
    // allow the child to arbitrarily pollute the parent namespace, and requires
    // cross-origin communication only in a limited set of cases that can be
    // computed independently by the parent.
    nsCOMPtr<nsPIDOMWindow> piWin = do_QueryInterface(aChild);
    NS_ENSURE_TRUE(piWin, false);
    Element* e = piWin->GetFrameElementInternal();
    return e && e->AttrValueIs(kNameSpaceID_None, nsGkAtoms::name,
                               aNameBeingResolved, eCaseMatters);
}

bool
WindowNamedPropertiesHandler::getOwnPropDescriptor(JSContext* aCx,
        JS::Handle<JSObject*> aProxy,
        JS::Handle<jsid> aId,
        bool /* unused */,
        JS::MutableHandle<JSPropertyDescriptor> aDesc)
const
{
    if (!JSID_IS_STRING(aId)) {
        // Nothing to do if we're resolving a non-string property.
        return true;
    }

    bool hasOnPrototype;
    if (!HasPropertyOnPrototype(aCx, aProxy, aId, &hasOnPrototype)) {
        return false;
    }
    if (hasOnPrototype) {
        return true;
    }

    nsAutoJSString str;
    if (!str.init(aCx, JSID_TO_STRING(aId))) {
        return false;
    }

    // Grab the DOM window.
    JS::Rooted<JSObject*> global(aCx, JS_GetGlobalForObject(aCx, aProxy));
    nsGlobalWindow* win = xpc::WindowOrNull(global);
    if (win->Length() > 0) {
        nsCOMPtr<nsIDOMWindow> childWin = win->GetChildWindow(str);
        if (childWin && ShouldExposeChildWindow(str, childWin)) {
            // We found a subframe of the right name. Shadowing via |var foo| in
            // global scope is still allowed, since |var| only looks up |own|
            // properties. But unqualified shadowing will fail, per-spec.
            JS::Rooted<JS::Value> v(aCx);
            if (!WrapObject(aCx, childWin, &v)) {
                return false;
            }
            aDesc.object().set(aProxy);
            aDesc.value().set(v);
            aDesc.setAttributes(JSPROP_ENUMERATE);
            return true;
        }
    }

    // The rest of this function is for HTML documents only.
    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(win->GetExtantDoc());
    if (!htmlDoc) {
        return true;
    }
    nsHTMLDocument* document = static_cast<nsHTMLDocument*>(htmlDoc.get());

    Element* element = document->GetElementById(str);
    if (element) {
        JS::Rooted<JS::Value> v(aCx);
        if (!WrapObject(aCx, element, &v)) {
            return false;
        }
        aDesc.object().set(aProxy);
        aDesc.value().set(v);
        aDesc.setAttributes(JSPROP_ENUMERATE);
        return true;
    }

    nsWrapperCache* cache;
    nsISupports* result = document->ResolveName(str, &cache);
    if (!result) {
        return true;
    }

    JS::Rooted<JS::Value> v(aCx);
    if (!WrapObject(aCx, result, cache, nullptr, &v)) {
        return false;
    }
    aDesc.object().set(aProxy);
    aDesc.value().set(v);
    aDesc.setAttributes(JSPROP_ENUMERATE);
    return true;
}

bool
WindowNamedPropertiesHandler::defineProperty(JSContext* aCx,
        JS::Handle<JSObject*> aProxy,
        JS::Handle<jsid> aId,
        JS::MutableHandle<JSPropertyDescriptor> aDesc) const
{
    ErrorResult rv;
    rv.ThrowTypeError(MSG_DEFINEPROPERTY_ON_GSP);
    rv.ReportErrorWithMessage(aCx);
    return false;
}

bool
WindowNamedPropertiesHandler::ownPropNames(JSContext* aCx,
        JS::Handle<JSObject*> aProxy,
        unsigned flags,
        JS::AutoIdVector& aProps) const
{
    // Grab the DOM window.
    nsGlobalWindow* win = xpc::WindowOrNull(JS_GetGlobalForObject(aCx, aProxy));
    nsTArray<nsString> names;
    win->GetSupportedNames(names);
    // Filter out the ones we wouldn't expose from getOwnPropertyDescriptor.
    // We iterate backwards so we can remove things from the list easily.
    for (size_t i = names.Length(); i > 0; ) {
        --i; // Now we're pointing at the next name we want to look at
        nsIDOMWindow* childWin = win->GetChildWindow(names[i]);
        if (!childWin || !ShouldExposeChildWindow(names[i], childWin)) {
            names.RemoveElementAt(i);
        }
    }
    if (!AppendNamedPropertyIds(aCx, aProxy, names, false, aProps)) {
        return false;
    }

    names.Clear();
    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(win->GetExtantDoc());
    if (!htmlDoc) {
        return true;
    }
    nsHTMLDocument* document = static_cast<nsHTMLDocument*>(htmlDoc.get());
    document->GetSupportedNames(flags, names);

    JS::AutoIdVector docProps(aCx);
    if (!AppendNamedPropertyIds(aCx, aProxy, names, false, docProps)) {
        return false;
    }

    return js::AppendUnique(aCx, aProps, docProps);
}

bool
WindowNamedPropertiesHandler::delete_(JSContext* aCx,
                                      JS::Handle<JSObject*> aProxy,
                                      JS::Handle<jsid> aId, bool* aBp) const
{
    *aBp = false;
    return true;
}

static bool
ResolveWindowNamedProperty(JSContext* aCx, JS::Handle<JSObject*> aWrapper,
                           JS::Handle<JSObject*> aObj, JS::Handle<jsid> aId,
                           JS::MutableHandle<JSPropertyDescriptor> aDesc)
{
    {
        JSAutoCompartment ac(aCx, aObj);
        if (!js::GetProxyHandler(aObj)->getOwnPropertyDescriptor(aCx, aObj, aId,
                aDesc)) {
            return false;
        }
    }

    if (aDesc.object()) {
        aDesc.object().set(aWrapper);

        return JS_WrapPropertyDescriptor(aCx, aDesc);
    }

    return true;
}

static bool
EnumerateWindowNamedProperties(JSContext* aCx, JS::Handle<JSObject*> aWrapper,
                               JS::Handle<JSObject*> aObj,
                               JS::AutoIdVector& aProps)
{
    JSAutoCompartment ac(aCx, aObj);
    return js::GetProxyHandler(aObj)->ownPropertyKeys(aCx, aObj, aProps);
}

const NativePropertyHooks sWindowNamedPropertiesNativePropertyHooks[] = { {
        ResolveWindowNamedProperty,
        EnumerateWindowNamedProperties,
        { nullptr, nullptr },
        prototypes::id::_ID_Count,
        constructors::id::_ID_Count,
        nullptr
    }
};

static const DOMIfaceAndProtoJSClass WindowNamedPropertiesClass = {
    PROXY_CLASS_DEF("WindowProperties",
    JSCLASS_IS_DOMIFACEANDPROTOJSCLASS),
    eNamedPropertiesObject,
    sWindowNamedPropertiesNativePropertyHooks,
    "[object WindowProperties]",
    prototypes::id::_ID_Count,
    0,
    EventTargetBinding::GetProtoObject
};

// static
JSObject*
WindowNamedPropertiesHandler::Create(JSContext* aCx,
                                     JS::Handle<JSObject*> aProto)
{
    // Note: since the scope polluter proxy lives on the window's prototype
    // chain, it needs a singleton type to avoid polluting type information
    // for properties on the window.
    JS::Rooted<JSObject*> gsp(aCx);
    js::ProxyOptions options;
    options.setSingleton(true);
    options.setClass(&WindowNamedPropertiesClass.mBase);
    return js::NewProxyObject(aCx, WindowNamedPropertiesHandler::getInstance(),
                              JS::NullHandleValue, aProto,
                              js::GetGlobalForObjectCrossCompartment(aProto),
                              options);
}

} // namespace dom