gecko/js/xpconnect/wrappers/XrayWrapper.cpp
2013-06-28 14:01:09 -07:00

1814 lines
64 KiB
C++

/* -*- 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 "FilteringWrapper.h"
#include "WaiveXrayWrapper.h"
#include "WrapperFactory.h"
#include "nsIContent.h"
#include "nsContentUtils.h"
#include "XPCWrapper.h"
#include "xpcprivate.h"
#include "jsapi.h"
#include "nsJSUtils.h"
#include "mozilla/dom/BindingUtils.h"
#include "nsGlobalWindow.h"
using namespace mozilla::dom;
using namespace JS;
using namespace mozilla;
using js::PropertyDescriptor;
using js::Wrapper;
using js::IsCrossCompartmentWrapper;
using js::UncheckedUnwrap;
using js::CheckedUnwrap;
namespace xpc {
static const uint32_t JSSLOT_RESOLVING = 0;
namespace XrayUtils {
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;
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,
JSPropertyDescriptor *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, JSPropertyDescriptor *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,
JSPropertyDescriptor *desc, unsigned flags);
virtual bool resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper,
HandleObject holder, HandleId id,
JSPropertyDescriptor *desc, unsigned flags);
static bool defineProperty(JSContext *cx, HandleObject wrapper, HandleId id,
PropertyDescriptor *desc,
Handle<PropertyDescriptor> 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,
PropertyDescriptor *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,
JSPropertyDescriptor *desc, unsigned flags);
virtual bool resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper,
HandleObject holder, HandleId id,
JSPropertyDescriptor *desc, unsigned flags);
static bool defineProperty(JSContext *cx, HandleObject wrapper, HandleId id,
PropertyDescriptor *desc,
Handle<PropertyDescriptor> 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<nsIPrincipal*>(v.toPrivate());
}
static void
ExpandoObjectFinalize(JSFreeOp *fop, JSObject *obj)
{
// Release the principal.
nsIPrincipal *principal = GetExpandoObjectPrincipal(obj);
NS_RELEASE(principal);
}
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.address()))
return NULL;
// 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.address()))
return NULL;
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.address()))
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.
JSBool
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;
}
JSBool
holder_set(JSContext *cx, HandleObject wrapper, HandleId id, JSBool 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,
PropertyDescriptor *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 <typename T>
static T*
As(JSObject *wrapper)
{
XPCWrappedNative *wn = XPCWrappedNativeXrayTraits::getWN(wrapper);
nsCOMPtr<T> native = do_QueryWrappedNative(wn);
return native;
}
template <typename T>
static bool
Is(JSObject *wrapper)
{
return !!As<T>(wrapper);
}
static nsQueryInterface
do_QueryInterfaceNative(JSContext* cx, HandleObject wrapper);
void
XPCWrappedNativeXrayTraits::preserveWrapper(JSObject *target)
{
XPCWrappedNative *wn = XPCWrappedNative::Get(target);
nsRefPtr<nsXPCClassInfo> ci;
CallQueryInterface(wn->Native(), getter_AddRefs(ci));
if (ci)
ci->PreserveWrapper(wn->Native());
}
bool
XPCWrappedNativeXrayTraits::resolveNativeProperty(JSContext *cx, HandleObject wrapper,
HandleObject holder, HandleId id,
JSPropertyDescriptor *desc, unsigned flags)
{
MOZ_ASSERT(js::GetObjectJSClass(holder) == &HolderClass);
desc->obj = NULL;
// 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->obj = holder;
desc->attrs = JSPROP_ENUMERATE;
desc->getter = NULL;
desc->setter = NULL;
desc->shortid = 0;
desc->value = JSVAL_VOID;
RootedValue fval(cx, JSVAL_VOID);
if (member->IsConstant()) {
if (!member->GetConstantValue(ccx, iface, &desc->value)) {
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;
}
desc->attrs |= JSPROP_GETTER;
if (member->IsWritableAttribute())
desc->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.
desc->attrs |= JSPROP_SHARED;
} else {
// This is a method. Clone a function for it.
if (!member->NewFunctionObject(ccx, iface, wrapper, &desc->value)) {
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->getter = JS_PropertyStub;
desc->setter = JS_StrictPropertyStub;
}
if (!JS_WrapValue(cx, &desc->value) || !JS_WrapValue(cx, fval.address()))
return false;
if (desc->attrs & JSPROP_GETTER)
desc->getter = js::CastAsJSPropertyOp(JSVAL_TO_OBJECT(fval));
if (desc->attrs & JSPROP_SETTER)
desc->setter = js::CastAsJSStrictPropertyOp(JSVAL_TO_OBJECT(fval));
// Define the property.
return JS_DefinePropertyById(cx, holder, id, desc->value,
desc->getter, desc->setter, desc->attrs);
}
static JSBool
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.address());
}
bool
XrayTraits::resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper,
HandleObject wrapper, HandleObject holder, HandleId id,
PropertyDescriptor *desc, unsigned flags)
{
desc->obj = NULL;
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->obj) {
if (!JS_WrapPropertyDescriptor(cx, desc))
return false;
// Pretend the property lives on the wrapper.
desc->obj = wrapper;
return true;
}
return true;
}
bool
XPCWrappedNativeXrayTraits::resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper,
HandleObject wrapper, HandleObject holder,
HandleId id, PropertyDescriptor *desc, unsigned flags)
{
// Call the common code.
bool ok = XrayTraits::resolveOwnProperty(cx, jsWrapper, wrapper, holder,
id, desc, flags);
if (!ok || desc->obj)
return ok;
// Check for indexed access on a window.
int32_t index = GetArrayIndexFromId(cx, id);
if (IsArrayIndex(index)) {
nsGlobalWindow* win =
static_cast<nsGlobalWindow*>(As<nsPIDOMWindow>(wrapper));
// Note: As() unwraps outer windows to get to the inner window.
if (win) {
bool unused;
nsCOMPtr<nsIDOMWindow> subframe = win->IndexedGetter(index, unused);
if (subframe) {
nsGlobalWindow* global = static_cast<nsGlobalWindow*>(subframe.get());
global->EnsureInnerWindow();
JSObject* obj = global->FastGetGlobalJSObject();
if (MOZ_UNLIKELY(!obj)) {
// It's gone?
return xpc::Throw(cx, NS_ERROR_FAILURE);
}
desc->value = ObjectValue(*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));
JSBool 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,
PropertyDescriptor *desc,
Handle<PropertyDescriptor> existingDesc, bool *defined)
{
*defined = false;
JSObject *holder = singleton.ensureHolder(cx, wrapper);
if (isResolving(cx, holder, id)) {
if (!(desc->attrs & (JSPROP_GETTER | JSPROP_SETTER))) {
if (!desc->getter)
desc->getter = holder_get;
if (!desc->setter)
desc->setter = holder_set;
}
*defined = true;
return JS_DefinePropertyById(cx, holder, id, desc->value, desc->getter, desc->setter,
desc->attrs);
}
// 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<nsIDOMWindow>(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]);
JSBool 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(NULL));
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,
JSPropertyDescriptor *desc, unsigned flags)
{
RootedObject obj(cx, getTargetObject(wrapper));
if (!XrayResolveNativeProperty(cx, wrapper, obj, id, desc))
return false;
NS_ASSERTION(!desc->obj || desc->obj == wrapper,
"What did we resolve this on?");
return true;
}
bool
DOMXrayTraits::resolveOwnProperty(JSContext *cx, Wrapper &jsWrapper, HandleObject wrapper,
HandleObject holder, HandleId id,
JSPropertyDescriptor *desc, unsigned flags)
{
// Call the common code.
bool ok = XrayTraits::resolveOwnProperty(cx, jsWrapper, wrapper, holder,
id, desc, flags);
if (!ok || desc->obj)
return ok;
RootedObject obj(cx, getTargetObject(wrapper));
if (!XrayResolveOwnProperty(cx, wrapper, obj, id, desc, flags))
return false;
NS_ASSERTION(!desc->obj || desc->obj == wrapper,
"What did we resolve this on?");
return true;
}
bool
DOMXrayTraits::defineProperty(JSContext *cx, HandleObject wrapper, HandleId id,
PropertyDescriptor *desc,
Handle<PropertyDescriptor> existingDesc, bool *defined)
{
if (!existingDesc.obj())
return true;
JS::Rooted<JSObject*> 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<JSObject*> 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));
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().address());
}
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));
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().address()))
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 <typename Base, typename Traits>
XrayWrapper<Base, Traits>::XrayWrapper(unsigned flags)
: Base(flags | WrapperFactory::IS_XRAY_WRAPPER_FLAG)
{
}
template <typename Base, typename Traits>
XrayWrapper<Base, Traits>::~XrayWrapper()
{
}
namespace XrayUtils {
JSObject *
GetNativePropertiesObject(JSContext *cx, JSObject *wrapper)
{
NS_ASSERTION(js::IsWrapper(wrapper) && WrapperFactory::IsXrayWrapper(wrapper),
"bad object passed in");
JSObject *holder = GetHolder(wrapper);
NS_ASSERTION(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<PropertyDescriptor> desc(cx);
Wrapper *handler = Wrapper::wrapperHandler(wrapper);
// Try resolveOwnProperty.
Maybe<ResolvingId> resolvingId;
if (traits == &XPCWrappedNativeXrayTraits::singleton)
resolvingId.construct(cx, wrapper, id);
if (!traits->resolveOwnProperty(cx, *handler, wrapper, holder, id, desc.address(), 0))
return false;
if (desc.object()) {
*hasProp = true;
return true;
}
// Try the holder.
JSBool 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.address(), 0))
return false;
*hasProp = !!desc.object();
return true;
}
} // namespace XrayUtils
static JSBool
XrayToString(JSContext *cx, unsigned argc, jsval *vp)
{
RootedObject wrapper(cx, JS_THIS_OBJECT(cx, vp));
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, vp);
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<const jschar *>(result.get()),
result.Length());
if (!str)
return false;
*vp = STRING_TO_JSVAL(str);
return true;
}
#ifdef DEBUG
static void
DEBUG_CheckXBLCallable(JSContext *cx, JSObject *obj)
{
MOZ_ASSERT(!js::IsCrossCompartmentWrapper(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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::isExtensible(JSContext *cx, JS::Handle<JSObject*> 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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::preventExtensions(JSContext *cx, HandleObject wrapper)
{
// See above.
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CANT_CHANGE_EXTENSIBILITY);
return false;
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::getPropertyDescriptor(JSContext *cx, HandleObject wrapper, HandleId id,
PropertyDescriptor *desc, unsigned flags)
{
assertEnteredPolicy(cx, wrapper, id);
RootedObject holder(cx, Traits::singleton.ensureHolder(cx, wrapper));
if (Traits::isResolving(cx, holder, id)) {
desc->obj = NULL;
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->obj = wrapper;
desc->attrs = JSPROP_ENUMERATE|JSPROP_SHARED;
desc->getter = wrappedJSObject_getter;
desc->setter = NULL;
desc->shortid = 0;
desc->value = 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->obj && !JS_GetPropertyDescriptorById(cx, holder, id, 0, desc))
return false;
if (desc->obj) {
desc->obj = 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;
if (!desc->obj && Traits::Type == XrayForWrappedNative && JSID_IS_STRING(id) &&
(win = static_cast<nsGlobalWindow*>(As<nsPIDOMWindow>(wrapper))))
{
nsDependentJSString name(id);
nsCOMPtr<nsIDOMWindow> childDOMWin = win->GetChildWindow(name);
if (childDOMWin) {
nsGlobalWindow *cwin = static_cast<nsGlobalWindow*>(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->obj &&
id == nsXPConnect::GetRuntimeInstance()->GetStringID(XPCJSRuntime::IDX_TO_STRING))
{
JSFunction *toString = JS_NewFunction(cx, XrayToString, 0, 0, holder, "toString");
if (!toString)
return false;
desc->obj = wrapper;
desc->attrs = 0;
desc->getter = NULL;
desc->setter = NULL;
desc->shortid = 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 our own scope (the XBL scope).
// Make sure to assert that.
nsCOMPtr<nsIContent> content;
if (!desc->obj &&
EnsureCompartmentPrivate(wrapper)->scope->IsXBLScope() &&
(content = do_QueryInterfaceNative(cx, wrapper)))
{
if (!nsContentUtils::LookupBindingMember(cx, content, id, desc))
return false;
DEBUG_CheckXBLLookup(cx, desc);
}
// If we still have nothing, we're done.
if (!desc->obj)
return true;
if (!JS_DefinePropertyById(cx, holder, id, desc->value, desc->getter,
desc->setter, desc->attrs) ||
!JS_GetPropertyDescriptorById(cx, holder, id, flags, desc))
{
return false;
}
MOZ_ASSERT(desc->obj);
desc->obj = wrapper;
return true;
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::getOwnPropertyDescriptor(JSContext *cx, HandleObject wrapper, HandleId id,
PropertyDescriptor *desc, unsigned flags)
{
assertEnteredPolicy(cx, wrapper, id);
RootedObject holder(cx, Traits::singleton.ensureHolder(cx, wrapper));
if (Traits::isResolving(cx, holder, id)) {
desc->obj = NULL;
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->obj)
desc->obj = 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, PropertyDescriptor *orig,
MutableHandle<PropertyDescriptor> 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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::defineProperty(JSContext *cx, HandleObject wrapper,
HandleId id, PropertyDescriptor *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<PropertyDescriptor> existing_desc(cx);
if (!getOwnPropertyDescriptor(cx, wrapper, id, existing_desc.address(), 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<PropertyDescriptor> wrappedDesc(cx, *desc);
if (!JS_WrapPropertyDescriptor(cx, wrappedDesc.address()))
return false;
// Fix up Xray waivers.
if (!RecreateLostWaivers(cx, desc, &wrappedDesc))
return false;
return JS_DefinePropertyById(cx, expandoObject, id, wrappedDesc.value(),
wrappedDesc.getter(), wrappedDesc.setter(),
wrappedDesc.get().attrs);
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::getOwnPropertyNames(JSContext *cx, HandleObject wrapper,
AutoIdVector &props)
{
assertEnteredPolicy(cx, wrapper, JSID_VOID);
return enumerate(cx, wrapper, JSITER_OWNONLY | JSITER_HIDDEN, props);
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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));
JSBool b = true;
if (expando) {
JSAutoCompartment ac(cx, expando);
RootedValue v(cx);
if (!JS_DeletePropertyById2(cx, expando, id, v.address()) ||
!JS_ValueToBoolean(cx, v, &b))
{
return false;
}
}
*bp = !!b;
return true;
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::enumerate(JSContext *cx, HandleObject wrapper,
AutoIdVector &props)
{
return enumerate(cx, wrapper, 0, props);
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::keys(JSContext *cx, HandleObject wrapper,
AutoIdVector &props)
{
// Skip our Base if it isn't already ProxyHandler.
return js::BaseProxyHandler::keys(cx, wrapper, props);
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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 <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::call(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args)
{
assertEnteredPolicy(cx, wrapper, JSID_VOID);
return Traits::call(cx, wrapper, args, Base::singleton);
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::construct(JSContext *cx, HandleObject wrapper, const JS::CallArgs &args)
{
assertEnteredPolicy(cx, wrapper, JSID_VOID);
return Traits::construct(cx, wrapper, args, Base::singleton);
}
template <typename Base, typename Traits>
bool
XrayWrapper<Base, Traits>::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<>
SCPermissiveXrayXPCWN SCPermissiveXrayXPCWN::singleton(0);
template class SCPermissiveXrayXPCWN;
template<>
SCSecurityXrayXPCWN SCSecurityXrayXPCWN::singleton(0);
template class SCSecurityXrayXPCWN;
template<>
SCPermissiveXrayDOM SCPermissiveXrayDOM::singleton(0);
template class SCPermissiveXrayDOM;
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);
}
}