/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=4 sw=4 et tw=99 ft=cpp: * * 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 "XrayWrapper.h" #include "AccessCheck.h" #include "WrapperFactory.h" #include "nsIContent.h" #include "nsContentUtils.h" #include "XPCWrapper.h" #include "xpcprivate.h" #include "jsapi.h" #include "jsprf.h" #include "nsJSUtils.h" #include "mozilla/dom/BindingUtils.h" #include "nsGlobalWindow.h" using namespace mozilla::dom; using namespace JS; using namespace mozilla; using js::Wrapper; using js::IsCrossCompartmentWrapper; using js::UncheckedUnwrap; using js::CheckedUnwrap; namespace xpc { static const uint32_t JSSLOT_RESOLVING = 0; namespace XrayUtils { const JSClass HolderClass = { "NativePropertyHolder", JSCLASS_HAS_RESERVED_SLOTS(2), JS_PropertyStub, JS_DeletePropertyStub, holder_get, holder_set, JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub }; } using namespace XrayUtils; XrayType GetXrayType(JSObject *obj) { obj = js::UncheckedUnwrap(obj, /* stopAtOuter = */ false); if (mozilla::dom::UseDOMXray(obj)) return XrayForDOMObject; const js::Class* clasp = js::GetObjectClass(obj); if (IS_WN_CLASS(clasp) || clasp->ext.innerObject) return XrayForWrappedNative; return NotXray; } ResolvingId::ResolvingId(JSContext *cx, HandleObject wrapper, HandleId id) : mId(id), mHolder(cx, getHolderObject(wrapper)), mPrev(getResolvingId(mHolder)), mXrayShadowing(false) { js::SetReservedSlot(mHolder, JSSLOT_RESOLVING, js::PrivateValue(this)); } ResolvingId::~ResolvingId() { MOZ_ASSERT(getResolvingId(mHolder) == this, "unbalanced ResolvingIds"); js::SetReservedSlot(mHolder, JSSLOT_RESOLVING, js::PrivateValue(mPrev)); } bool ResolvingId::isXrayShadowing(jsid id) { if (!mXrayShadowing) return false; return mId == id; } bool ResolvingId::isResolving(jsid id) { for (ResolvingId *cur = this; cur; cur = cur->mPrev) { if (cur->mId == id) return true; } return false; } ResolvingId * ResolvingId::getResolvingId(JSObject *holder) { MOZ_ASSERT(strcmp(JS_GetClass(holder)->name, "NativePropertyHolder") == 0); return (ResolvingId *)js::GetReservedSlot(holder, JSSLOT_RESOLVING).toPrivate(); } JSObject * ResolvingId::getHolderObject(JSObject *wrapper) { return &js::GetProxyExtra(wrapper, 0).toObject(); } ResolvingId * ResolvingId::getResolvingIdFromWrapper(JSObject *wrapper) { return getResolvingId(getHolderObject(wrapper)); } class MOZ_STACK_CLASS ResolvingIdDummy { public: ResolvingIdDummy(JSContext *cx, HandleObject wrapper, HandleId id) { } }; class XrayTraits { public: static JSObject* getTargetObject(JSObject *wrapper) { return js::UncheckedUnwrap(wrapper, /* stopAtOuter = */ false); } virtual bool resolveNativeProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) = 0; // NB: resolveOwnProperty may decide whether or not to cache what it finds // on the holder. If the result is not cached, the lookup will happen afresh // for each access, which is the right thing for things like dynamic NodeList // properties. virtual bool resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags); static bool call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance) { MOZ_ASSUME_UNREACHABLE("Call trap currently implemented only for XPCWNs"); } static bool construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance) { MOZ_ASSUME_UNREACHABLE("Call trap currently implemented only for XPCWNs"); } virtual void preserveWrapper(JSObject *target) = 0; JSObject* getExpandoObject(JSContext *cx, HandleObject target, HandleObject consumer); JSObject* ensureExpandoObject(JSContext *cx, HandleObject wrapper, HandleObject target); JSObject* getHolder(JSObject *wrapper); JSObject* ensureHolder(JSContext *cx, HandleObject wrapper); virtual JSObject* createHolder(JSContext *cx, JSObject *wrapper) = 0; virtual JSObject* getExpandoChain(JSObject *obj) = 0; virtual void setExpandoChain(JSObject *obj, JSObject *chain) = 0; bool cloneExpandoChain(JSContext *cx, HandleObject dst, HandleObject src); private: bool expandoObjectMatchesConsumer(JSContext *cx, HandleObject expandoObject, nsIPrincipal *consumerOrigin, HandleObject exclusiveGlobal); JSObject* getExpandoObjectInternal(JSContext *cx, HandleObject target, nsIPrincipal *origin, JSObject *exclusiveGlobal); JSObject* attachExpandoObject(JSContext *cx, HandleObject target, nsIPrincipal *origin, HandleObject exclusiveGlobal); }; class XPCWrappedNativeXrayTraits : public XrayTraits { public: static const XrayType Type = XrayForWrappedNative; virtual bool resolveNativeProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags); virtual bool resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags); static bool defineProperty(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandle desc, Handle existingDesc, bool *defined); static bool enumerateNames(JSContext *cx, HandleObject wrapper, unsigned flags, AutoIdVector &props); static bool call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance); static bool construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance); static bool isResolving(JSContext *cx, JSObject *holder, jsid id); static bool resolveDOMCollectionProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags); static XPCWrappedNative* getWN(JSObject *wrapper) { return XPCWrappedNative::Get(getTargetObject(wrapper)); } virtual void preserveWrapper(JSObject *target); typedef ResolvingId ResolvingIdImpl; virtual JSObject* createHolder(JSContext *cx, JSObject *wrapper); virtual JSObject* getExpandoChain(JSObject *obj) { return GetWNExpandoChain(obj); } virtual void setExpandoChain(JSObject *obj, JSObject *chain) { SetWNExpandoChain(obj, chain); } static XPCWrappedNativeXrayTraits singleton; }; class DOMXrayTraits : public XrayTraits { public: static const XrayType Type = XrayForDOMObject; virtual bool resolveNativeProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags); virtual bool resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags); static bool defineProperty(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandle desc, Handle existingDesc, bool *defined); static bool enumerateNames(JSContext *cx, HandleObject wrapper, unsigned flags, AutoIdVector &props); static bool call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance); static bool construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance); static bool isResolving(JSContext *cx, JSObject *holder, jsid id) { return false; } typedef ResolvingIdDummy ResolvingIdImpl; virtual void preserveWrapper(JSObject *target); virtual JSObject* createHolder(JSContext *cx, JSObject *wrapper); virtual JSObject* getExpandoChain(JSObject *obj) { return mozilla::dom::GetXrayExpandoChain(obj); } virtual void setExpandoChain(JSObject *obj, JSObject *chain) { mozilla::dom::SetXrayExpandoChain(obj, chain); } static DOMXrayTraits singleton; }; XPCWrappedNativeXrayTraits XPCWrappedNativeXrayTraits::singleton; DOMXrayTraits DOMXrayTraits::singleton; XrayTraits* GetXrayTraits(JSObject *obj) { switch (GetXrayType(obj)) { case XrayForDOMObject: return &DOMXrayTraits::singleton; case XrayForWrappedNative: return &XPCWrappedNativeXrayTraits::singleton; default: return nullptr; } } /* * Xray expando handling. * * We hang expandos for Xray wrappers off a reserved slot on the target object * so that same-origin compartments can share expandos for a given object. We * have a linked list of expando objects, one per origin. The properties on these * objects are generally wrappers pointing back to the compartment that applied * them. * * The expando objects should _never_ be exposed to script. The fact that they * live in the target compartment is a detail of the implementation, and does * not imply that code in the target compartment should be allowed to inspect * them. They are private to the origin that placed them. */ enum ExpandoSlots { JSSLOT_EXPANDO_NEXT = 0, JSSLOT_EXPANDO_ORIGIN, JSSLOT_EXPANDO_EXCLUSIVE_GLOBAL, JSSLOT_EXPANDO_COUNT }; static nsIPrincipal* ObjectPrincipal(JSObject *obj) { return GetCompartmentPrincipal(js::GetObjectCompartment(obj)); } static nsIPrincipal* GetExpandoObjectPrincipal(JSObject *expandoObject) { Value v = JS_GetReservedSlot(expandoObject, JSSLOT_EXPANDO_ORIGIN); return static_cast(v.toPrivate()); } static void ExpandoObjectFinalize(JSFreeOp *fop, JSObject *obj) { // Release the principal. nsIPrincipal *principal = GetExpandoObjectPrincipal(obj); NS_RELEASE(principal); } const JSClass ExpandoObjectClass = { "XrayExpandoObject", JSCLASS_HAS_RESERVED_SLOTS(JSSLOT_EXPANDO_COUNT), JS_PropertyStub, JS_DeletePropertyStub, JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, ExpandoObjectFinalize }; bool XrayTraits::expandoObjectMatchesConsumer(JSContext *cx, HandleObject expandoObject, nsIPrincipal *consumerOrigin, HandleObject exclusiveGlobal) { MOZ_ASSERT(js::IsObjectInContextCompartment(expandoObject, cx)); // First, compare the principals. nsIPrincipal *o = GetExpandoObjectPrincipal(expandoObject); bool equal; // Note that it's very important here to ignore document.domain. We // pull the principal for the expando object off of the first consumer // for a given origin, and freely share the expandos amongst multiple // same-origin consumers afterwards. However, this means that we have // no way to know whether _all_ consumers have opted in to collaboration // by explicitly setting document.domain. So we just mandate that expando // sharing is unaffected by it. nsresult rv = consumerOrigin->EqualsIgnoringDomain(o, &equal); if (NS_FAILED(rv) || !equal) return false; // Sandboxes want exclusive expando objects. JSObject *owner = JS_GetReservedSlot(expandoObject, JSSLOT_EXPANDO_EXCLUSIVE_GLOBAL) .toObjectOrNull(); if (!owner && !exclusiveGlobal) return true; // The exclusive global should always be wrapped in the target's compartment. MOZ_ASSERT(!exclusiveGlobal || js::IsObjectInContextCompartment(exclusiveGlobal, cx)); MOZ_ASSERT(!owner || js::IsObjectInContextCompartment(owner, cx)); return owner == exclusiveGlobal; } JSObject * XrayTraits::getExpandoObjectInternal(JSContext *cx, HandleObject target, nsIPrincipal *origin, JSObject *exclusiveGlobalArg) { // The expando object lives in the compartment of the target, so all our // work needs to happen there. RootedObject exclusiveGlobal(cx, exclusiveGlobalArg); JSAutoCompartment ac(cx, target); if (!JS_WrapObject(cx, &exclusiveGlobal)) return nullptr; // Iterate through the chain, looking for a same-origin object. RootedObject head(cx, getExpandoChain(target)); while (head) { if (expandoObjectMatchesConsumer(cx, head, origin, exclusiveGlobal)) return head; head = JS_GetReservedSlot(head, JSSLOT_EXPANDO_NEXT).toObjectOrNull(); } // Not found. return nullptr; } JSObject * XrayTraits::getExpandoObject(JSContext *cx, HandleObject target, HandleObject consumer) { JSObject *consumerGlobal = js::GetGlobalForObjectCrossCompartment(consumer); bool isSandbox = !strcmp(js::GetObjectJSClass(consumerGlobal)->name, "Sandbox"); return getExpandoObjectInternal(cx, target, ObjectPrincipal(consumer), isSandbox ? consumerGlobal : nullptr); } JSObject * XrayTraits::attachExpandoObject(JSContext *cx, HandleObject target, nsIPrincipal *origin, HandleObject exclusiveGlobal) { // Make sure the compartments are sane. MOZ_ASSERT(js::IsObjectInContextCompartment(target, cx)); MOZ_ASSERT(!exclusiveGlobal || js::IsObjectInContextCompartment(exclusiveGlobal, cx)); // No duplicates allowed. MOZ_ASSERT(!getExpandoObjectInternal(cx, target, origin, exclusiveGlobal)); // Create the expando object. We parent it directly to the target object. RootedObject expandoObject(cx, JS_NewObjectWithGivenProto(cx, &ExpandoObjectClass, nullptr, target)); if (!expandoObject) return nullptr; // AddRef and store the principal. NS_ADDREF(origin); JS_SetReservedSlot(expandoObject, JSSLOT_EXPANDO_ORIGIN, PRIVATE_TO_JSVAL(origin)); // Note the exclusive global, if any. JS_SetReservedSlot(expandoObject, JSSLOT_EXPANDO_EXCLUSIVE_GLOBAL, OBJECT_TO_JSVAL(exclusiveGlobal)); // If this is our first expando object, take the opportunity to preserve // the wrapper. This keeps our expandos alive even if the Xray wrapper gets // collected. RootedObject chain(cx, getExpandoChain(target)); if (!chain) preserveWrapper(target); // Insert it at the front of the chain. JS_SetReservedSlot(expandoObject, JSSLOT_EXPANDO_NEXT, OBJECT_TO_JSVAL(chain)); setExpandoChain(target, expandoObject); return expandoObject; } JSObject * XrayTraits::ensureExpandoObject(JSContext *cx, HandleObject wrapper, HandleObject target) { // Expando objects live in the target compartment. JSAutoCompartment ac(cx, target); JSObject *expandoObject = getExpandoObject(cx, target, wrapper); if (!expandoObject) { // If the object is a sandbox, we don't want it to share expandos with // anyone else, so we tag it with the sandbox global. // // NB: We first need to check the class, _then_ wrap for the target's // compartment. RootedObject consumerGlobal(cx, js::GetGlobalForObjectCrossCompartment(wrapper)); bool isSandbox = !strcmp(js::GetObjectJSClass(consumerGlobal)->name, "Sandbox"); if (!JS_WrapObject(cx, &consumerGlobal)) return nullptr; expandoObject = attachExpandoObject(cx, target, ObjectPrincipal(wrapper), isSandbox ? (HandleObject)consumerGlobal : NullPtr()); } return expandoObject; } bool XrayTraits::cloneExpandoChain(JSContext *cx, HandleObject dst, HandleObject src) { MOZ_ASSERT(js::IsObjectInContextCompartment(dst, cx)); MOZ_ASSERT(getExpandoChain(dst) == nullptr); RootedObject oldHead(cx, getExpandoChain(src)); while (oldHead) { RootedObject exclusive(cx, JS_GetReservedSlot(oldHead, JSSLOT_EXPANDO_EXCLUSIVE_GLOBAL) .toObjectOrNull()); if (!JS_WrapObject(cx, &exclusive)) return false; JSObject *newHead = attachExpandoObject(cx, dst, GetExpandoObjectPrincipal(oldHead), exclusive); if (!JS_CopyPropertiesFrom(cx, newHead, oldHead)) return false; oldHead = JS_GetReservedSlot(oldHead, JSSLOT_EXPANDO_NEXT).toObjectOrNull(); } return true; } namespace XrayUtils { bool CloneExpandoChain(JSContext *cx, JSObject *dstArg, JSObject *srcArg) { RootedObject dst(cx, dstArg); RootedObject src(cx, srcArg); return GetXrayTraits(src)->cloneExpandoChain(cx, dst, src); } } static JSObject * GetHolder(JSObject *obj) { return &js::GetProxyExtra(obj, 0).toObject(); } JSObject* XrayTraits::getHolder(JSObject *wrapper) { MOZ_ASSERT(WrapperFactory::IsXrayWrapper(wrapper)); js::Value v = js::GetProxyExtra(wrapper, 0); return v.isObject() ? &v.toObject() : nullptr; } JSObject* XrayTraits::ensureHolder(JSContext *cx, HandleObject wrapper) { RootedObject holder(cx, getHolder(wrapper)); if (holder) return holder; holder = createHolder(cx, wrapper); // virtual trap. if (holder) js::SetProxyExtra(wrapper, 0, ObjectValue(*holder)); return holder; } bool XPCWrappedNativeXrayTraits::isResolving(JSContext *cx, JSObject *holder, jsid id) { ResolvingId *cur = ResolvingId::getResolvingId(holder); if (!cur) return false; return cur->isResolving(id); } // Some DOM objects have shared properties that don't have an explicit // getter/setter and rely on the class getter/setter. We install a // class getter/setter on the holder object to trigger them. bool holder_get(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandleValue vp) { // JSClass::getProperty is wacky enough that it's hard to be sure someone // can't inherit this getter by prototyping a random object to an // XrayWrapper. Be safe. NS_ENSURE_TRUE(WrapperFactory::IsXrayWrapper(wrapper), true); JSObject *holder = GetHolder(wrapper); XPCWrappedNative *wn = XPCWrappedNativeXrayTraits::getWN(wrapper); if (NATIVE_HAS_FLAG(wn, WantGetProperty)) { JSAutoCompartment ac(cx, holder); bool retval = true; nsresult rv = wn->GetScriptableCallback()->GetProperty(wn, cx, wrapper, id, vp.address(), &retval); if (NS_FAILED(rv) || !retval) { if (retval) XPCThrower::Throw(rv, cx); return false; } } return true; } bool holder_set(JSContext *cx, HandleObject wrapper, HandleId id, bool strict, MutableHandleValue vp) { // JSClass::setProperty is wacky enough that it's hard to be sure someone // can't inherit this getter by prototyping a random object to an // XrayWrapper. Be safe. NS_ENSURE_TRUE(WrapperFactory::IsXrayWrapper(wrapper), true); JSObject *holder = GetHolder(wrapper); if (XPCWrappedNativeXrayTraits::isResolving(cx, holder, id)) { return true; } XPCWrappedNative *wn = XPCWrappedNativeXrayTraits::getWN(wrapper); if (NATIVE_HAS_FLAG(wn, WantSetProperty)) { JSAutoCompartment ac(cx, holder); bool retval = true; nsresult rv = wn->GetScriptableCallback()->SetProperty(wn, cx, wrapper, id, vp.address(), &retval); if (NS_FAILED(rv) || !retval) { if (retval) XPCThrower::Throw(rv, cx); return false; } } return true; } class AutoSetWrapperNotShadowing { public: AutoSetWrapperNotShadowing(ResolvingId *resolvingId MOZ_GUARD_OBJECT_NOTIFIER_PARAM) { MOZ_GUARD_OBJECT_NOTIFIER_INIT; MOZ_ASSERT(resolvingId); mResolvingId = resolvingId; mResolvingId->mXrayShadowing = true; } ~AutoSetWrapperNotShadowing() { mResolvingId->mXrayShadowing = false; } private: MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER ResolvingId *mResolvingId; }; // This is called after the resolveNativeProperty could not find any property // with the given id. At this point we can check for DOM specific collections // like document["formName"] because we already know that it is not shadowing // any native property. bool XPCWrappedNativeXrayTraits::resolveDOMCollectionProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) { // If we are not currently resolving this id and resolveNative is called // we don't do anything. (see defineProperty in case of shadowing is forbidden). ResolvingId *rid = ResolvingId::getResolvingId(holder); if (!rid || rid->mId != id) return true; XPCWrappedNative *wn = getWN(wrapper); if (!wn) { // This should NEVER happen, but let's be extra careful here // because of the reported crashes (Bug 832091). XPCThrower::Throw(NS_ERROR_UNEXPECTED, cx); return false; } if (!NATIVE_HAS_FLAG(wn, WantNewResolve)) return true; ResolvingId *resolvingId = ResolvingId::getResolvingIdFromWrapper(wrapper); if (!resolvingId) { // This should NEVER happen, but let's be extra careful here // becaue of the reported crashes (Bug 832091). XPCThrower::Throw(NS_ERROR_UNEXPECTED, cx); return false; } // Setting the current ResolvingId in non-shadowing mode. So for this id // Xray won't ignore DOM specific collection properties temporarily. AutoSetWrapperNotShadowing asw(resolvingId); bool retval = true; RootedObject pobj(cx); nsresult rv = wn->GetScriptableInfo()->GetCallback()->NewResolve(wn, cx, wrapper, id, flags, pobj.address(), &retval); if (NS_FAILED(rv)) { if (retval) XPCThrower::Throw(rv, cx); return false; } if (pobj && !JS_GetPropertyDescriptorById(cx, holder, id, 0, desc)) return false; return true; } template static T* As(JSObject *wrapper) { XPCWrappedNative *wn = XPCWrappedNativeXrayTraits::getWN(wrapper); nsCOMPtr native = do_QueryWrappedNative(wn); return native; } template static bool Is(JSObject *wrapper) { return !!As(wrapper); } static nsQueryInterface do_QueryInterfaceNative(JSContext* cx, HandleObject wrapper); void XPCWrappedNativeXrayTraits::preserveWrapper(JSObject *target) { XPCWrappedNative *wn = XPCWrappedNative::Get(target); nsRefPtr ci; CallQueryInterface(wn->Native(), getter_AddRefs(ci)); if (ci) ci->PreserveWrapper(wn->Native()); } bool XPCWrappedNativeXrayTraits::resolveNativeProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) { MOZ_ASSERT(js::GetObjectJSClass(holder) == &HolderClass); desc.object().set(nullptr); // This will do verification and the method lookup for us. RootedObject target(cx, getTargetObject(wrapper)); XPCCallContext ccx(JS_CALLER, cx, target, NullPtr(), id); // There are no native numeric properties, so we can shortcut here. We will // not find the property. However we want to support non shadowing dom // specific collection properties like window.frames, so we still have to // check for those. if (!JSID_IS_STRING(id)) { /* Not found */ return resolveDOMCollectionProperty(cx, wrapper, holder, id, desc, flags); } XPCNativeInterface *iface; XPCNativeMember *member; XPCWrappedNative *wn = getWN(wrapper); if (ccx.GetWrapper() != wn || !wn->IsValid()) { // Something is wrong. If the wrapper is not even valid let's not risk // calling resolveDOMCollectionProperty. return true; } else if (!(iface = ccx.GetInterface()) || !(member = ccx.GetMember())) { /* Not found */ return resolveDOMCollectionProperty(cx, wrapper, holder, id, desc, flags); } desc.object().set(holder); desc.setAttributes(JSPROP_ENUMERATE); desc.setGetter(nullptr); desc.setSetter(nullptr); desc.setShortId(0); desc.value().set(JSVAL_VOID); RootedValue fval(cx, JSVAL_VOID); if (member->IsConstant()) { if (!member->GetConstantValue(ccx, iface, desc.value().address())) { JS_ReportError(cx, "Failed to convert constant native property to JS value"); return false; } } else if (member->IsAttribute()) { // This is a getter/setter. Clone a function for it. if (!member->NewFunctionObject(ccx, iface, wrapper, fval.address())) { JS_ReportError(cx, "Failed to clone function object for native getter/setter"); return false; } unsigned attrs = desc.attributes(); attrs |= JSPROP_GETTER; if (member->IsWritableAttribute()) attrs |= JSPROP_SETTER; // Make the property shared on the holder so no slot is allocated // for it. This avoids keeping garbage alive through that slot. attrs |= JSPROP_SHARED; desc.setAttributes(attrs); } else { // This is a method. Clone a function for it. if (!member->NewFunctionObject(ccx, iface, wrapper, desc.value().address())) { JS_ReportError(cx, "Failed to clone function object for native function"); return false; } // Without a wrapper the function would live on the prototype. Since we // don't have one, we have to avoid calling the scriptable helper's // GetProperty method for this property, so stub out the getter and // setter here explicitly. desc.setGetter(JS_PropertyStub); desc.setSetter(JS_StrictPropertyStub); } if (!JS_WrapValue(cx, desc.value()) || !JS_WrapValue(cx, &fval)) return false; if (desc.hasGetterObject()) desc.setGetterObject(&fval.toObject()); if (desc.hasSetterObject()) desc.setSetterObject(&fval.toObject()); // Define the property. return JS_DefinePropertyById(cx, holder, id, desc.value(), desc.getter(), desc.setter(), desc.attributes()); } static bool wrappedJSObject_getter(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandleValue vp) { if (!IsWrapper(wrapper) || !WrapperFactory::IsXrayWrapper(wrapper)) { JS_ReportError(cx, "Unexpected object"); return false; } vp.set(OBJECT_TO_JSVAL(wrapper)); return WrapperFactory::WaiveXrayAndWrap(cx, vp); } bool XrayTraits::resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) { desc.object().set(nullptr); RootedObject target(cx, getTargetObject(wrapper)); RootedObject expando(cx, getExpandoObject(cx, target, wrapper)); // Check for expando properties first. Note that the expando object lives // in the target compartment. if (expando) { JSAutoCompartment ac(cx, expando); if (!JS_GetPropertyDescriptorById(cx, expando, id, 0, desc)) return false; } if (desc.object()) { if (!JS_WrapPropertyDescriptor(cx, desc)) return false; // Pretend the property lives on the wrapper. desc.object().set(wrapper); return true; } return true; } bool XPCWrappedNativeXrayTraits::resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) { // Call the common code. bool ok = XrayTraits::resolveOwnProperty(cx, jsWrapper, wrapper, holder, id, desc, flags); if (!ok || desc.object()) return ok; // Check for indexed access on a window. int32_t index = GetArrayIndexFromId(cx, id); if (IsArrayIndex(index)) { nsGlobalWindow* win = static_cast(As(wrapper)); // Note: As() unwraps outer windows to get to the inner window. if (win) { bool unused; nsCOMPtr subframe = win->IndexedGetter(index, unused); if (subframe) { nsGlobalWindow* global = static_cast(subframe.get()); global->EnsureInnerWindow(); JSObject* obj = global->FastGetGlobalJSObject(); if (MOZ_UNLIKELY(!obj)) { // It's gone? return xpc::Throw(cx, NS_ERROR_FAILURE); } desc.value().setObject(*obj); mozilla::dom::FillPropertyDescriptor(desc, wrapper, true); return JS_WrapPropertyDescriptor(cx, desc); } } } // Xray wrappers don't use the regular wrapper hierarchy, so we should be // in the wrapper's compartment here, not the wrappee. MOZ_ASSERT(js::IsObjectInContextCompartment(wrapper, cx)); bool hasProp; if (!JS_HasPropertyById(cx, holder, id, &hasProp)) { return false; } if (!hasProp) { XPCWrappedNative *wn = getWN(wrapper); // Run the resolve hook of the wrapped native. if (!NATIVE_HAS_FLAG(wn, WantNewResolve)) { return true; } bool retval = true; RootedObject pobj(cx); nsIXPCScriptable *callback = wn->GetScriptableInfo()->GetCallback(); nsresult rv = callback->NewResolve(wn, cx, wrapper, id, flags, pobj.address(), &retval); if (NS_FAILED(rv)) { if (retval) XPCThrower::Throw(rv, cx); return false; } MOZ_ASSERT(!pobj || (JS_HasPropertyById(cx, holder, id, &hasProp) && hasProp), "id got defined somewhere else?"); } // resolveOwnProperty must return a non-empty |desc| if and only if an |own| // property was found on the object. However, given how the NewResolve setup // works, we can't run the resolve hook if the holder already has a property // of the same name. So if there was a pre-existing property on the holder, // we have to use it. But we have no way of knowing if it corresponded to an // |own| or non-|own| property, since both get cached on the holder and the // |own|-ness information is lost. // // So we just over-zealously call things |own| here. This can cause us to // return non-|own| properties from Object.getOwnPropertyDescriptor if // lookups are performed in a certain order, but we can probably live with // that until XPCWN Xrays go away with the new DOM bindings. return JS_GetPropertyDescriptorById(cx, holder, id, 0, desc); } bool XPCWrappedNativeXrayTraits::defineProperty(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandle desc, Handle existingDesc, bool *defined) { *defined = false; JSObject *holder = singleton.ensureHolder(cx, wrapper); if (isResolving(cx, holder, id)) { if (!desc.hasAttributes(JSPROP_GETTER | JSPROP_SETTER)) { if (!desc.getter()) desc.setGetter(holder_get); if (!desc.setter()) desc.setSetter(holder_set); } *defined = true; return JS_DefinePropertyById(cx, holder, id, desc.value(), desc.getter(), desc.setter(), desc.attributes()); } // Check for an indexed property on a Window. If that's happening, do // nothing but claim we defined it so it won't get added as an expando. int32_t index = GetArrayIndexFromId(cx, id); if (IsArrayIndex(index) && Is(wrapper)) { *defined = true; return true; } return true; } bool XPCWrappedNativeXrayTraits::enumerateNames(JSContext *cx, HandleObject wrapper, unsigned flags, AutoIdVector &props) { // Force all native properties to be materialized onto the wrapped native. AutoIdVector wnProps(cx); { RootedObject target(cx, singleton.getTargetObject(wrapper)); JSAutoCompartment ac(cx, target); if (!js::GetPropertyNames(cx, target, flags, &wnProps)) return false; } // Go through the properties we got and enumerate all native ones. for (size_t n = 0; n < wnProps.length(); ++n) { RootedId id(cx, wnProps[n]); bool hasProp; if (!JS_HasPropertyById(cx, wrapper, id, &hasProp)) return false; if (hasProp) props.append(id); } return true; } JSObject * XPCWrappedNativeXrayTraits::createHolder(JSContext *cx, JSObject *wrapper) { JSObject *global = JS_GetGlobalForObject(cx, wrapper); JSObject *holder = JS_NewObjectWithGivenProto(cx, &HolderClass, nullptr, global); if (!holder) return nullptr; js::SetReservedSlot(holder, JSSLOT_RESOLVING, PrivateValue(nullptr)); return holder; } bool XPCWrappedNativeXrayTraits::call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance) { // Run the resolve hook of the wrapped native. XPCWrappedNative *wn = getWN(wrapper); if (NATIVE_HAS_FLAG(wn, WantCall)) { XPCCallContext ccx(JS_CALLER, cx, wrapper, NullPtr(), JSID_VOIDHANDLE, args.length(), args.array(), args.rval().address()); if (!ccx.IsValid()) return false; bool ok = true; nsresult rv = wn->GetScriptableInfo()->GetCallback()->Call( wn, cx, wrapper, args, &ok); if (NS_FAILED(rv)) { if (ok) XPCThrower::Throw(rv, cx); return false; } } return true; } bool XPCWrappedNativeXrayTraits::construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance) { // Run the resolve hook of the wrapped native. XPCWrappedNative *wn = getWN(wrapper); if (NATIVE_HAS_FLAG(wn, WantConstruct)) { XPCCallContext ccx(JS_CALLER, cx, wrapper, NullPtr(), JSID_VOIDHANDLE, args.length(), args.array(), args.rval().address()); if (!ccx.IsValid()) return false; bool ok = true; nsresult rv = wn->GetScriptableInfo()->GetCallback()->Construct( wn, cx, wrapper, args, &ok); if (NS_FAILED(rv)) { if (ok) XPCThrower::Throw(rv, cx); return false; } } return true; } bool DOMXrayTraits::resolveNativeProperty(JSContext *cx, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) { RootedObject obj(cx, getTargetObject(wrapper)); if (!XrayResolveNativeProperty(cx, wrapper, obj, id, desc)) return false; MOZ_ASSERT(!desc.object() || desc.object() == wrapper, "What did we resolve this on?"); return true; } bool DOMXrayTraits::resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper, HandleObject holder, HandleId id, MutableHandle desc, unsigned flags) { // Call the common code. bool ok = XrayTraits::resolveOwnProperty(cx, jsWrapper, wrapper, holder, id, desc, flags); if (!ok || desc.object()) return ok; RootedObject obj(cx, getTargetObject(wrapper)); if (!XrayResolveOwnProperty(cx, wrapper, obj, id, desc, flags)) return false; MOZ_ASSERT(!desc.object() || desc.object() == wrapper, "What did we resolve this on?"); return true; } bool DOMXrayTraits::defineProperty(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandle desc, Handle existingDesc, bool *defined) { if (!existingDesc.object()) return true; JS::Rooted obj(cx, getTargetObject(wrapper)); return XrayDefineProperty(cx, wrapper, obj, id, desc, defined); } bool DOMXrayTraits::enumerateNames(JSContext *cx, HandleObject wrapper, unsigned flags, AutoIdVector &props) { JS::Rooted obj(cx, getTargetObject(wrapper)); return XrayEnumerateProperties(cx, wrapper, obj, flags, props); } bool DOMXrayTraits::call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance) { RootedObject obj(cx, getTargetObject(wrapper)); const js::Class* clasp = js::GetObjectClass(obj); // What we have is either a WebIDL interface object, a WebIDL prototype // object, or a WebIDL instance object. WebIDL prototype objects never have // a clasp->call. WebIDL interface objects we want to invoke on the xray // compartment. WebIDL instance objects either don't have a clasp->call or // are using "legacycaller", which basically means plug-ins. We want to // call those on the content compartment. if (clasp->flags & JSCLASS_IS_DOMIFACEANDPROTOJSCLASS) { if (!clasp->call) { js_ReportIsNotFunction(cx, JS::ObjectValue(*wrapper)); return false; } // call it on the Xray compartment if (!clasp->call(cx, args.length(), args.base())) return false; } else { // This is only reached for WebIDL instance objects, and in practice // only for plugins. Just call them on the content compartment. if (!baseInstance.call(cx, wrapper, args)) return false; } return JS_WrapValue(cx, args.rval()); } bool DOMXrayTraits::construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args, js::Wrapper& baseInstance) { RootedObject obj(cx, getTargetObject(wrapper)); MOZ_ASSERT(mozilla::dom::HasConstructor(obj)); const js::Class* clasp = js::GetObjectClass(obj); // See comments in DOMXrayTraits::call() explaining what's going on here. if (clasp->flags & JSCLASS_IS_DOMIFACEANDPROTOJSCLASS) { if (!clasp->construct) { js_ReportIsNotFunction(cx, JS::ObjectValue(*wrapper)); return false; } if (!clasp->construct(cx, args.length(), args.base())) return false; } else { if (!baseInstance.construct(cx, wrapper, args)) return false; } if (!args.rval().isObject() || !JS_WrapValue(cx, args.rval())) return false; return true; } void DOMXrayTraits::preserveWrapper(JSObject *target) { nsISupports *identity = mozilla::dom::UnwrapDOMObjectToISupports(target); if (!identity) return; nsWrapperCache* cache = nullptr; CallQueryInterface(identity, &cache); if (cache) cache->PreserveWrapper(identity); } JSObject* DOMXrayTraits::createHolder(JSContext *cx, JSObject *wrapper) { return JS_NewObjectWithGivenProto(cx, nullptr, nullptr, JS_GetGlobalForObject(cx, wrapper)); } template XrayWrapper::XrayWrapper(unsigned flags) : Base(flags | WrapperFactory::IS_XRAY_WRAPPER_FLAG) { } template XrayWrapper::~XrayWrapper() { } namespace XrayUtils { JSObject * GetNativePropertiesObject(JSContext *cx, JSObject *wrapper) { MOZ_ASSERT(js::IsWrapper(wrapper) && WrapperFactory::IsXrayWrapper(wrapper), "bad object passed in"); JSObject *holder = GetHolder(wrapper); MOZ_ASSERT(holder, "uninitialized wrapper being used?"); return holder; } bool IsXrayResolving(JSContext *cx, HandleObject wrapper, HandleId id) { if (!WrapperFactory::IsXrayWrapper(wrapper) || GetXrayType(wrapper) != XrayForWrappedNative) { return false; } JSObject *holder = XPCWrappedNativeXrayTraits::singleton.ensureHolder(cx, wrapper); return XPCWrappedNativeXrayTraits::isResolving(cx, holder, id); } bool HasNativeProperty(JSContext *cx, HandleObject wrapper, HandleId id, bool *hasProp) { MOZ_ASSERT(WrapperFactory::IsXrayWrapper(wrapper)); XrayTraits *traits = GetXrayTraits(wrapper); MOZ_ASSERT(traits); RootedObject holder(cx, traits->ensureHolder(cx, wrapper)); NS_ENSURE_TRUE(holder, false); *hasProp = false; Rooted desc(cx); Wrapper *handler = Wrapper::wrapperHandler(wrapper); // Try resolveOwnProperty. Maybe resolvingId; if (traits == &XPCWrappedNativeXrayTraits::singleton) resolvingId.construct(cx, wrapper, id); if (!traits->resolveOwnProperty(cx, *handler, wrapper, holder, id, &desc, 0)) return false; if (desc.object()) { *hasProp = true; return true; } // Try the holder. bool found = false; if (!JS_AlreadyHasOwnPropertyById(cx, holder, id, &found)) return false; if (found) { *hasProp = true; return true; } // Try resolveNativeProperty. if (!traits->resolveNativeProperty(cx, wrapper, holder, id, &desc, 0)) return false; *hasProp = !!desc.object(); return true; } } // namespace XrayUtils static bool XrayToString(JSContext *cx, unsigned argc, Value *vp) { CallArgs args = CallArgsFromVp(argc, vp); if (!args.thisv().isObject()) { JS_ReportError(cx, "XrayToString called on an incompatible object"); return false; } RootedObject wrapper(cx, &args.thisv().toObject()); if (!wrapper) return false; if (IsWrapper(wrapper) && GetProxyHandler(wrapper) == &sandboxCallableProxyHandler) { wrapper = xpc::SandboxCallableProxyHandler::wrappedObject(wrapper); } if (!IsWrapper(wrapper) || !WrapperFactory::IsXrayWrapper(wrapper)) { JS_ReportError(cx, "XrayToString called on an incompatible object"); return false; } RootedObject obj(cx, XrayTraits::getTargetObject(wrapper)); static const char start[] = "[object XrayWrapper "; static const char end[] = "]"; if (UseDOMXray(obj)) return NativeToString(cx, wrapper, obj, start, end, args.rval()); nsAutoString result; result.AppendASCII(start); XPCCallContext ccx(JS_CALLER, cx, obj); XPCWrappedNative *wn = XPCWrappedNativeXrayTraits::getWN(wrapper); char *wrapperStr = wn->ToString(); if (!wrapperStr) { JS_ReportOutOfMemory(cx); return false; } result.AppendASCII(wrapperStr); JS_smprintf_free(wrapperStr); result.AppendASCII(end); JSString *str = JS_NewUCStringCopyN(cx, reinterpret_cast(result.get()), result.Length()); if (!str) return false; args.rval().setString(str); return true; } #ifdef DEBUG static void DEBUG_CheckXBLCallable(JSContext *cx, JSObject *obj) { // In general, we shouldn't have cross-compartment wrappers here, because // we should be running in an XBL scope, and the content prototype should // contain wrappers to functions defined in the XBL scope. But if the node // has been adopted into another compartment, those prototypes will now point // to a different XBL scope (which is ok). MOZ_ASSERT_IF(js::IsCrossCompartmentWrapper(obj), xpc::IsXBLScope(js::GetObjectCompartment(js::UncheckedUnwrap(obj)))); MOZ_ASSERT(JS_ObjectIsCallable(cx, obj)); } static void DEBUG_CheckXBLLookup(JSContext *cx, JSPropertyDescriptor *desc) { if (!desc->obj) return; if (!desc->value.isUndefined()) { MOZ_ASSERT(desc->value.isObject()); DEBUG_CheckXBLCallable(cx, &desc->value.toObject()); } if (desc->getter) { MOZ_ASSERT(desc->attrs & JSPROP_GETTER); DEBUG_CheckXBLCallable(cx, JS_FUNC_TO_DATA_PTR(JSObject *, desc->getter)); } if (desc->setter) { MOZ_ASSERT(desc->attrs & JSPROP_SETTER); DEBUG_CheckXBLCallable(cx, JS_FUNC_TO_DATA_PTR(JSObject *, desc->setter)); } } #else #define DEBUG_CheckXBLLookup(a, b) {} #endif template bool XrayWrapper::isExtensible(JSContext *cx, JS::Handle wrapper, bool *extensible) { // Xray wrappers are supposed to provide a clean view of the target // reflector, hiding any modifications by script in the target scope. So // even if that script freezes the reflector, we don't want to make that // visible to the caller. DOM reflectors are always extensible by default, // so we can just return true here. *extensible = true; return true; } template bool XrayWrapper::preventExtensions(JSContext *cx, HandleObject wrapper) { // See above. JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_CANT_CHANGE_EXTENSIBILITY); return false; } template bool XrayWrapper::getPropertyDescriptor(JSContext *cx, HandleObject wrapper, HandleId id, JS::MutableHandle desc, unsigned flags) { assertEnteredPolicy(cx, wrapper, id); RootedObject holder(cx, Traits::singleton.ensureHolder(cx, wrapper)); if (Traits::isResolving(cx, holder, id)) { desc.object().set(nullptr); return true; } typename Traits::ResolvingIdImpl resolving(cx, wrapper, id); if (!holder) return false; // Only chrome wrappers and same-origin xrays (used by jetpack sandboxes) // get .wrappedJSObject. We can check this by determining if the compartment // of the wrapper subsumes that of the wrappee. XPCJSRuntime* rt = nsXPConnect::GetRuntimeInstance(); if (AccessCheck::wrapperSubsumes(wrapper) && id == rt->GetStringID(XPCJSRuntime::IDX_WRAPPED_JSOBJECT)) { desc.object().set(wrapper); desc.setAttributes(JSPROP_ENUMERATE|JSPROP_SHARED); desc.setGetter(wrappedJSObject_getter); desc.setSetter(nullptr); desc.setShortId(0); desc.value().set(JSVAL_VOID); return true; } // Ordering is important here. // // We first need to call resolveOwnProperty, even before checking the holder, // because there might be a new dynamic |own| property that appears and // shadows a previously-resolved non-own property that we cached on the // holder. This can happen with indexed properties on NodeLists, for example, // which are |own| value props. // // resolveOwnProperty may or may not cache what it finds on the holder, // depending on how ephemeral it decides the property is. XPCWN |own| // properties generally end up on the holder via NewResolve, whereas // NodeList |own| properties don't get defined on the holder, since they're // supposed to be dynamic. This means that we have to first check the result // of resolveOwnProperty, and _then_, if that comes up blank, check the // holder for any cached native properties. // // Finally, we call resolveNativeProperty, which checks non-own properties, // and unconditionally caches what it finds on the holder. // Check resolveOwnProperty. if (!Traits::singleton.resolveOwnProperty(cx, *this, wrapper, holder, id, desc, flags)) return false; // Check the holder. if (!desc.object() && !JS_GetPropertyDescriptorById(cx, holder, id, 0, desc)) return false; if (desc.object()) { desc.object().set(wrapper); return true; } // Nothing in the cache. Call through, and cache the result. if (!Traits::singleton.resolveNativeProperty(cx, wrapper, holder, id, desc, flags)) return false; // We need to handle named access on the Window somewhere other than // Traits::resolveOwnProperty, because per spec it happens on the Global // Scope Polluter and thus the resulting properties are non-|own|. However, // we're set up (above) to cache (on the holder) anything that comes out of // resolveNativeProperty, which we don't want for something dynamic like // named access. So we just handle it separately here. nsGlobalWindow *win = nullptr; if (!desc.object() && (Traits::Type == XrayForWrappedNative) && JSID_IS_STRING(id) && (win = static_cast(As(wrapper)))) { nsDependentJSString name(id); nsCOMPtr childDOMWin = win->GetChildWindow(name); if (childDOMWin) { nsGlobalWindow *cwin = static_cast(childDOMWin.get()); JSObject *childObj = cwin->FastGetGlobalJSObject(); if (MOZ_UNLIKELY(!childObj)) return xpc::Throw(cx, NS_ERROR_FAILURE); mozilla::dom::FillPropertyDescriptor(desc, wrapper, ObjectValue(*childObj), /* readOnly = */ true); return JS_WrapPropertyDescriptor(cx, desc); } } if (!desc.object() && id == nsXPConnect::GetRuntimeInstance()->GetStringID(XPCJSRuntime::IDX_TO_STRING)) { JSFunction *toString = JS_NewFunction(cx, XrayToString, 0, 0, holder, "toString"); if (!toString) return false; desc.object().set(wrapper); desc.setAttributes(0); desc.setGetter(nullptr); desc.setSetter(nullptr); desc.setShortId(0); desc.value().setObject(*JS_GetFunctionObject(toString)); } // If we're a special scope for in-content XBL, our script expects to see // the bound XBL methods and attributes when accessing content. However, // these members are implemented in content via custom-spliced prototypes, // and thus aren't visible through Xray wrappers unless we handle them // explicitly. So we check if we're running in such a scope, and if so, // whether the wrappee is a bound element. If it is, we do a lookup via // specialized XBL machinery. // // While we have to do some sketchy walking through content land, we should // be protected by read-only/non-configurable properties, and any functions // we end up with should _always_ be living in an XBL scope (usually ours, // but could be another if the node has been adopted). // // Make sure to assert this. nsCOMPtr content; if (!desc.object() && EnsureCompartmentPrivate(wrapper)->scope->IsXBLScope() && (content = do_QueryInterfaceNative(cx, wrapper))) { if (!nsContentUtils::LookupBindingMember(cx, content, id, desc)) return false; DEBUG_CheckXBLLookup(cx, desc.address()); } // If we still have nothing, we're done. if (!desc.object()) return true; if (!JS_DefinePropertyById(cx, holder, id, desc.value(), desc.getter(), desc.setter(), desc.attributes()) || !JS_GetPropertyDescriptorById(cx, holder, id, flags, desc)) { return false; } MOZ_ASSERT(desc.object()); desc.object().set(wrapper); return true; } template bool XrayWrapper::getOwnPropertyDescriptor(JSContext *cx, HandleObject wrapper, HandleId id, JS::MutableHandle desc, unsigned flags) { assertEnteredPolicy(cx, wrapper, id); RootedObject holder(cx, Traits::singleton.ensureHolder(cx, wrapper)); if (Traits::isResolving(cx, holder, id)) { desc.object().set(nullptr); return true; } typename Traits::ResolvingIdImpl resolving(cx, wrapper, id); // NB: Nothing we do here acts on the wrapped native itself, so we don't // enter our policy. if (!Traits::singleton.resolveOwnProperty(cx, *this, wrapper, holder, id, desc, flags)) return false; if (desc.object()) desc.object().set(wrapper); return true; } // Consider what happens when chrome does |xray.expando = xray.wrappedJSObject|. // // Since the expando comes from the target compartment, wrapping it back into // the target compartment to define it on the expando object ends up stripping // off the Xray waiver that gives |xray| and |xray.wrappedJSObject| different // identities. This is generally the right thing to do when wrapping across // compartments, but is incorrect in the special case of the Xray expando // object. Manually re-apply Xrays if necessary. // // NB: In order to satisfy the invariants of WaiveXray, we need to pass // in an object sans security wrapper, which means we need to strip off any // potential same-compartment security wrapper that may have been applied // to the content object. This is ok, because the the expando object is only // ever accessed by code across the compartment boundary. static bool RecreateLostWaivers(JSContext *cx, JSPropertyDescriptor *orig, MutableHandle wrapped) { // Compute whether the original objects were waived, and implicitly, whether // they were objects at all. bool valueWasWaived = orig->value.isObject() && WrapperFactory::HasWaiveXrayFlag(&orig->value.toObject()); bool getterWasWaived = (orig->attrs & JSPROP_GETTER) && WrapperFactory::HasWaiveXrayFlag(JS_FUNC_TO_DATA_PTR(JSObject*, orig->getter)); bool setterWasWaived = (orig->attrs & JSPROP_SETTER) && WrapperFactory::HasWaiveXrayFlag(JS_FUNC_TO_DATA_PTR(JSObject*, orig->setter)); // Recreate waivers. Note that for value, we need an extra UncheckedUnwrap // to handle same-compartment security wrappers (see above). This should // never happen for getters/setters. RootedObject rewaived(cx); if (valueWasWaived && !IsCrossCompartmentWrapper(&wrapped.value().toObject())) { rewaived = &wrapped.value().toObject(); rewaived = WrapperFactory::WaiveXray(cx, UncheckedUnwrap(rewaived)); NS_ENSURE_TRUE(rewaived, false); wrapped.value().set(ObjectValue(*rewaived)); } if (getterWasWaived && !IsCrossCompartmentWrapper(wrapped.getterObject())) { MOZ_ASSERT(CheckedUnwrap(wrapped.getterObject())); rewaived = WrapperFactory::WaiveXray(cx, wrapped.getterObject()); NS_ENSURE_TRUE(rewaived, false); wrapped.setGetterObject(rewaived); } if (setterWasWaived && !IsCrossCompartmentWrapper(wrapped.setterObject())) { MOZ_ASSERT(CheckedUnwrap(wrapped.setterObject())); rewaived = WrapperFactory::WaiveXray(cx, wrapped.setterObject()); NS_ENSURE_TRUE(rewaived, false); wrapped.setSetterObject(rewaived); } return true; } template bool XrayWrapper::defineProperty(JSContext *cx, HandleObject wrapper, HandleId id, MutableHandle desc) { assertEnteredPolicy(cx, wrapper, id); // NB: We still need JSRESOLVE_ASSIGNING here for the time being, because it // tells things like nodelists whether they should create the property or not. Rooted existing_desc(cx); if (!getOwnPropertyDescriptor(cx, wrapper, id, &existing_desc, JSRESOLVE_ASSIGNING)) return false; if (existing_desc.object() && existing_desc.isPermanent()) return true; // silently ignore attempt to overwrite native property bool defined = false; if (!Traits::defineProperty(cx, wrapper, id, desc, existing_desc, &defined)) return false; if (defined) return true; // We're placing an expando. The expando objects live in the target // compartment, so we need to enter it. RootedObject target(cx, Traits::singleton.getTargetObject(wrapper)); JSAutoCompartment ac(cx, target); // Grab the relevant expando object. RootedObject expandoObject(cx, Traits::singleton.ensureExpandoObject(cx, wrapper, target)); if (!expandoObject) return false; // Wrap the property descriptor for the target compartment. Rooted wrappedDesc(cx, desc); if (!JS_WrapPropertyDescriptor(cx, &wrappedDesc)) return false; // Fix up Xray waivers. if (!RecreateLostWaivers(cx, desc.address(), &wrappedDesc)) return false; return JS_DefinePropertyById(cx, expandoObject, id, wrappedDesc.value(), wrappedDesc.getter(), wrappedDesc.setter(), wrappedDesc.get().attrs); } template bool XrayWrapper::getOwnPropertyNames(JSContext *cx, HandleObject wrapper, AutoIdVector &props) { assertEnteredPolicy(cx, wrapper, JSID_VOID); return enumerate(cx, wrapper, JSITER_OWNONLY | JSITER_HIDDEN, props); } template bool XrayWrapper::delete_(JSContext *cx, HandleObject wrapper, HandleId id, bool *bp) { assertEnteredPolicy(cx, wrapper, id); // Check the expando object. RootedObject target(cx, Traits::getTargetObject(wrapper)); RootedObject expando(cx, Traits::singleton.getExpandoObject(cx, target, wrapper)); if (expando) { JSAutoCompartment ac(cx, expando); return JS_DeletePropertyById2(cx, expando, id, bp); } *bp = true; return true; } template bool XrayWrapper::enumerate(JSContext *cx, HandleObject wrapper, unsigned flags, AutoIdVector &props) { assertEnteredPolicy(cx, wrapper, JSID_VOID); if (!AccessCheck::wrapperSubsumes(wrapper)) { JS_ReportError(cx, "Not allowed to enumerate cross origin objects"); return false; } // Enumerate expando properties first. Note that the expando object lives // in the target compartment. RootedObject target(cx, Traits::singleton.getTargetObject(wrapper)); RootedObject expando(cx, Traits::singleton.getExpandoObject(cx, target, wrapper)); if (expando) { JSAutoCompartment ac(cx, expando); if (!js::GetPropertyNames(cx, expando, flags, &props)) return false; } if (!JS_WrapAutoIdVector(cx, props)) return false; return Traits::enumerateNames(cx, wrapper, flags, props); } template bool XrayWrapper::enumerate(JSContext *cx, HandleObject wrapper, AutoIdVector &props) { return enumerate(cx, wrapper, 0, props); } template bool XrayWrapper::get(JSContext *cx, HandleObject wrapper, HandleObject receiver, HandleId id, MutableHandleValue vp) { // Skip our Base if it isn't already ProxyHandler. // NB: None of the functions we call are prepared for the receiver not // being the wrapper, so ignore the receiver here. return js::BaseProxyHandler::get(cx, wrapper, wrapper, id, vp); } template bool XrayWrapper::set(JSContext *cx, HandleObject wrapper, HandleObject receiver, HandleId id, bool strict, MutableHandleValue vp) { // Skip our Base if it isn't already BaseProxyHandler. // NB: None of the functions we call are prepared for the receiver not // being the wrapper, so ignore the receiver here. return js::BaseProxyHandler::set(cx, wrapper, wrapper, id, strict, vp); } template bool XrayWrapper::has(JSContext *cx, HandleObject wrapper, HandleId id, bool *bp) { // Skip our Base if it isn't already ProxyHandler. return js::BaseProxyHandler::has(cx, wrapper, id, bp); } template bool XrayWrapper::hasOwn(JSContext *cx, HandleObject wrapper, HandleId id, bool *bp) { // Skip our Base if it isn't already ProxyHandler. return js::BaseProxyHandler::hasOwn(cx, wrapper, id, bp); } template bool XrayWrapper::keys(JSContext *cx, HandleObject wrapper, AutoIdVector &props) { // Skip our Base if it isn't already ProxyHandler. return js::BaseProxyHandler::keys(cx, wrapper, props); } template bool XrayWrapper::iterate(JSContext *cx, HandleObject wrapper, unsigned flags, MutableHandleValue vp) { // Skip our Base if it isn't already ProxyHandler. return js::BaseProxyHandler::iterate(cx, wrapper, flags, vp); } template bool XrayWrapper::call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args) { assertEnteredPolicy(cx, wrapper, JSID_VOID); return Traits::call(cx, wrapper, args, Base::singleton); } template bool XrayWrapper::construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args) { assertEnteredPolicy(cx, wrapper, JSID_VOID); return Traits::construct(cx, wrapper, args, Base::singleton); } template bool XrayWrapper::defaultValue(JSContext *cx, HandleObject wrapper, JSType hint, MutableHandleValue vp) { // Even if this isn't a security wrapper, Xray semantics dictate that we // run the DefaultValue algorithm directly on the Xray wrapper. // // NB: We don't have to worry about things with special [[DefaultValue]] // behavior like Date because we'll never have an XrayWrapper to them. return js::DefaultValue(cx, wrapper, hint, vp); } /* * The Permissive / Security variants should be used depending on whether the * compartment of the wrapper is guranteed to subsume the compartment of the * wrapped object (i.e. - whether it is safe from a security perspective to * unwrap the wrapper). */ template<> PermissiveXrayXPCWN PermissiveXrayXPCWN::singleton(0); template class PermissiveXrayXPCWN; template<> SecurityXrayXPCWN SecurityXrayXPCWN::singleton(0); template class SecurityXrayXPCWN; template<> PermissiveXrayDOM PermissiveXrayDOM::singleton(0); template class PermissiveXrayDOM; template<> SecurityXrayDOM SecurityXrayDOM::singleton(0); template class SecurityXrayDOM; template<> SCSecurityXrayXPCWN SCSecurityXrayXPCWN::singleton(0); template class SCSecurityXrayXPCWN; static nsQueryInterface do_QueryInterfaceNative(JSContext* cx, HandleObject wrapper) { nsISupports* nativeSupports; if (IsWrapper(wrapper) && WrapperFactory::IsXrayWrapper(wrapper)) { RootedObject target(cx, XrayTraits::getTargetObject(wrapper)); if (GetXrayType(target) == XrayForDOMObject) { nativeSupports = UnwrapDOMObjectToISupports(target); } else { XPCWrappedNative *wn = XPCWrappedNative::Get(target); nativeSupports = wn->Native(); } } else { nsIXPConnect *xpc = nsXPConnect::XPConnect(); nativeSupports = xpc->GetNativeOfWrapper(cx, wrapper); } return nsQueryInterface(nativeSupports); } }