/* -*- 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 "WindowNamedPropertiesHandler.h" #include "mozilla/dom/EventTargetBinding.h" #include "mozilla/dom/WindowBinding.h" #include "nsContentUtils.h" #include "nsDOMClassInfo.h" #include "nsDOMWindowList.h" #include "nsGlobalWindow.h" #include "nsHTMLDocument.h" #include "nsJSUtils.h" #include "xpcprivate.h" namespace mozilla { 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 } // namespace mozilla