jswrapper.h
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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/. */
#ifndef jswrapper_h
#define jswrapper_h
#include "mozilla/Attributes.h"
#include "js/Proxy.h"
namespace js {
/*
* Helper for Wrapper::New default options.
*
* Callers of Wrapper::New() who wish to specify a prototype for the created
* Wrapper, *MUST* construct a WrapperOptions with a JSContext.
*/
class MOZ_STACK_CLASS WrapperOptions : public ProxyOptions {
public:
WrapperOptions() : ProxyOptions(false),
proto_()
{}
explicit WrapperOptions(JSContext* cx) : ProxyOptions(false),
proto_()
{
proto_.emplace(cx);
}
inline JSObject* proto() const;
WrapperOptions& setProto(JSObject* protoArg) {
MOZ_ASSERT(proto_);
*proto_ = protoArg;
return *this;
}
private:
mozilla::Maybe<JS::RootedObject> proto_;
};
/*
* A wrapper is a proxy with a target object to which it generally forwards
* operations, but may restrict access to certain operations or augment those
* operations in various ways.
*
* A wrapper can be "unwrapped" in C++, exposing the underlying object.
* Callers should be careful to avoid unwrapping security wrappers in the wrong
* context.
*
* Important: If you add a method implementation here, you probably also need
* to add an override in CrossCompartmentWrapper. If you don't, you risk
* compartment mismatches. See bug 945826 comment 0.
*/
class JS_FRIEND_API(Wrapper) : public BaseProxyHandler
{
unsigned mFlags;
public:
explicit constexpr Wrapper(unsigned aFlags, bool aHasPrototype = false,
bool aHasSecurityPolicy = false)
: BaseProxyHandler(&family, aHasPrototype, aHasSecurityPolicy),
mFlags(aFlags)
{ }
virtual bool finalizeInBackground(const Value& priv) const override;
/* Standard internal methods. */
virtual bool getOwnPropertyDescriptor(JSContext* cx, HandleObject proxy, HandleId id,
MutableHandle<PropertyDescriptor> desc) const override;
virtual bool defineProperty(JSContext* cx, HandleObject proxy, HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result) const override;
virtual bool ownPropertyKeys(JSContext* cx, HandleObject proxy,
AutoIdVector& props) const override;
virtual bool delete_(JSContext* cx, HandleObject proxy, HandleId id,
ObjectOpResult& result) const override;
virtual bool enumerate(JSContext* cx, HandleObject proxy,
MutableHandleObject objp) const override;
virtual bool getPrototype(JSContext* cx, HandleObject proxy,
MutableHandleObject protop) const override;
virtual bool setPrototype(JSContext* cx, HandleObject proxy, HandleObject proto,
ObjectOpResult& result) const override;
virtual bool getPrototypeIfOrdinary(JSContext* cx, HandleObject proxy, bool* isOrdinary,
MutableHandleObject protop) const override;
virtual bool setImmutablePrototype(JSContext* cx, HandleObject proxy,
bool* succeeded) const override;
virtual bool preventExtensions(JSContext* cx, HandleObject proxy,
ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, HandleObject proxy, bool* extensible) const override;
virtual bool has(JSContext* cx, HandleObject proxy, HandleId id,
bool* bp) const override;
virtual bool get(JSContext* cx, HandleObject proxy, HandleValue receiver,
HandleId id, MutableHandleValue vp) const override;
virtual bool set(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v,
HandleValue receiver, ObjectOpResult& result) const override;
virtual bool call(JSContext* cx, HandleObject proxy, const CallArgs& args) const override;
virtual bool construct(JSContext* cx, HandleObject proxy, const CallArgs& args) const override;
/* SpiderMonkey extensions. */
virtual bool getPropertyDescriptor(JSContext* cx, HandleObject proxy, HandleId id,
MutableHandle<PropertyDescriptor> desc) const override;
virtual bool hasOwn(JSContext* cx, HandleObject proxy, HandleId id,
bool* bp) const override;
virtual bool getOwnEnumerablePropertyKeys(JSContext* cx, HandleObject proxy,
AutoIdVector& props) const override;
virtual bool nativeCall(JSContext* cx, IsAcceptableThis test, NativeImpl impl,
const CallArgs& args) const override;
virtual bool hasInstance(JSContext* cx, HandleObject proxy, MutableHandleValue v,
bool* bp) const override;
virtual bool getBuiltinClass(JSContext* cx, HandleObject proxy, ESClass* cls) const override;
virtual bool isArray(JSContext* cx, HandleObject proxy,
JS::IsArrayAnswer* answer) const override;
virtual const char* className(JSContext* cx, HandleObject proxy) const override;
virtual JSString* fun_toString(JSContext* cx, HandleObject proxy,
unsigned indent) const override;
virtual bool regexp_toShared(JSContext* cx, HandleObject proxy,
RegExpGuard* g) const override;
virtual bool boxedValue_unbox(JSContext* cx, HandleObject proxy,
MutableHandleValue vp) const override;
virtual bool isCallable(JSObject* obj) const override;
virtual bool isConstructor(JSObject* obj) const override;
virtual JSObject* weakmapKeyDelegate(JSObject* proxy) const override;
public:
using BaseProxyHandler::Action;
enum Flags {
CROSS_COMPARTMENT = 1 << 0,
LAST_USED_FLAG = CROSS_COMPARTMENT
};
static JSObject* New(JSContext* cx, JSObject* obj, const Wrapper* handler,
const WrapperOptions& options = WrapperOptions());
static JSObject* Renew(JSObject* existing, JSObject* obj, const Wrapper* handler);
static const Wrapper* wrapperHandler(JSObject* wrapper);
static JSObject* wrappedObject(JSObject* wrapper);
unsigned flags() const {
return mFlags;
}
static const char family;
static const Wrapper singleton;
static const Wrapper singletonWithPrototype;
static JSObject* defaultProto;
};
inline JSObject*
WrapperOptions::proto() const
{
return proto_ ? *proto_ : Wrapper::defaultProto;
}
/* Base class for all cross compartment wrapper handlers. */
class JS_FRIEND_API(CrossCompartmentWrapper) : public Wrapper
{
public:
explicit constexpr CrossCompartmentWrapper(unsigned aFlags, bool aHasPrototype = false,
bool aHasSecurityPolicy = false)
: Wrapper(CROSS_COMPARTMENT | aFlags, aHasPrototype, aHasSecurityPolicy)
{ }
/* Standard internal methods. */
virtual bool getOwnPropertyDescriptor(JSContext* cx, HandleObject wrapper, HandleId id,
MutableHandle<PropertyDescriptor> desc) const override;
virtual bool defineProperty(JSContext* cx, HandleObject wrapper, HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result) const override;
virtual bool ownPropertyKeys(JSContext* cx, HandleObject wrapper,
AutoIdVector& props) const override;
virtual bool delete_(JSContext* cx, HandleObject wrapper, HandleId id,
ObjectOpResult& result) const override;
virtual bool enumerate(JSContext* cx, HandleObject wrapper, MutableHandleObject objp) const override;
virtual bool getPrototype(JSContext* cx, HandleObject proxy,
MutableHandleObject protop) const override;
virtual bool setPrototype(JSContext* cx, HandleObject proxy, HandleObject proto,
ObjectOpResult& result) const override;
virtual bool getPrototypeIfOrdinary(JSContext* cx, HandleObject proxy, bool* isOrdinary,
MutableHandleObject protop) const override;
virtual bool setImmutablePrototype(JSContext* cx, HandleObject proxy,
bool* succeeded) const override;
virtual bool preventExtensions(JSContext* cx, HandleObject wrapper,
ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, HandleObject wrapper, bool* extensible) const override;
virtual bool has(JSContext* cx, HandleObject wrapper, HandleId id, bool* bp) const override;
virtual bool get(JSContext* cx, HandleObject wrapper, HandleValue receiver,
HandleId id, MutableHandleValue vp) const override;
virtual bool set(JSContext* cx, HandleObject wrapper, HandleId id, HandleValue v,
HandleValue receiver, ObjectOpResult& result) const override;
virtual bool call(JSContext* cx, HandleObject wrapper, const CallArgs& args) const override;
virtual bool construct(JSContext* cx, HandleObject wrapper, const CallArgs& args) const override;
/* SpiderMonkey extensions. */
virtual bool getPropertyDescriptor(JSContext* cx, HandleObject wrapper, HandleId id,
MutableHandle<PropertyDescriptor> desc) const override;
virtual bool hasOwn(JSContext* cx, HandleObject wrapper, HandleId id, bool* bp) const override;
virtual bool getOwnEnumerablePropertyKeys(JSContext* cx, HandleObject wrapper,
AutoIdVector& props) const override;
virtual bool nativeCall(JSContext* cx, IsAcceptableThis test, NativeImpl impl,
const CallArgs& args) const override;
virtual bool hasInstance(JSContext* cx, HandleObject wrapper, MutableHandleValue v,
bool* bp) const override;
virtual const char* className(JSContext* cx, HandleObject proxy) const override;
virtual JSString* fun_toString(JSContext* cx, HandleObject wrapper,
unsigned indent) const override;
virtual bool regexp_toShared(JSContext* cx, HandleObject proxy, RegExpGuard* g) const override;
virtual bool boxedValue_unbox(JSContext* cx, HandleObject proxy, MutableHandleValue vp) const override;
// Allocate CrossCompartmentWrappers in the nursery.
virtual bool canNurseryAllocate() const override { return true; }
static const CrossCompartmentWrapper singleton;
static const CrossCompartmentWrapper singletonWithPrototype;
};
class JS_FRIEND_API(OpaqueCrossCompartmentWrapper) : public CrossCompartmentWrapper
{
public:
explicit constexpr OpaqueCrossCompartmentWrapper() : CrossCompartmentWrapper(0)
{ }
/* Standard internal methods. */
virtual bool getOwnPropertyDescriptor(JSContext* cx, HandleObject wrapper, HandleId id,
MutableHandle<PropertyDescriptor> desc) const override;
virtual bool defineProperty(JSContext* cx, HandleObject wrapper, HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result) const override;
virtual bool ownPropertyKeys(JSContext* cx, HandleObject wrapper,
AutoIdVector& props) const override;
virtual bool delete_(JSContext* cx, HandleObject wrapper, HandleId id,
ObjectOpResult& result) const override;
virtual bool enumerate(JSContext* cx, HandleObject wrapper,
MutableHandleObject objp) const override;
virtual bool getPrototype(JSContext* cx, HandleObject wrapper,
MutableHandleObject protop) const override;
virtual bool setPrototype(JSContext* cx, HandleObject wrapper, HandleObject proto,
ObjectOpResult& result) const override;
virtual bool getPrototypeIfOrdinary(JSContext* cx, HandleObject wrapper, bool* isOrdinary,
MutableHandleObject protop) const override;
virtual bool setImmutablePrototype(JSContext* cx, HandleObject wrapper,
bool* succeeded) const override;
virtual bool preventExtensions(JSContext* cx, HandleObject wrapper,
ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, HandleObject wrapper, bool* extensible) const override;
virtual bool has(JSContext* cx, HandleObject wrapper, HandleId id,
bool* bp) const override;
virtual bool get(JSContext* cx, HandleObject wrapper, HandleValue receiver,
HandleId id, MutableHandleValue vp) const override;
virtual bool set(JSContext* cx, HandleObject wrapper, HandleId id, HandleValue v,
HandleValue receiver, ObjectOpResult& result) const override;
virtual bool call(JSContext* cx, HandleObject wrapper, const CallArgs& args) const override;
virtual bool construct(JSContext* cx, HandleObject wrapper, const CallArgs& args) const override;
/* SpiderMonkey extensions. */
virtual bool getPropertyDescriptor(JSContext* cx, HandleObject wrapper, HandleId id,
MutableHandle<PropertyDescriptor> desc) const override;
virtual bool hasOwn(JSContext* cx, HandleObject wrapper, HandleId id,
bool* bp) const override;
virtual bool getOwnEnumerablePropertyKeys(JSContext* cx, HandleObject wrapper,
AutoIdVector& props) const override;
virtual bool getBuiltinClass(JSContext* cx, HandleObject wrapper, ESClass* cls) const override;
virtual bool isArray(JSContext* cx, HandleObject obj,
JS::IsArrayAnswer* answer) const override;
virtual const char* className(JSContext* cx, HandleObject wrapper) const override;
virtual JSString* fun_toString(JSContext* cx, HandleObject proxy, unsigned indent) const override;
static const OpaqueCrossCompartmentWrapper singleton;
};
/*
* Base class for security wrappers. A security wrapper is potentially hiding
* all or part of some wrapped object thus SecurityWrapper defaults to denying
* access to the wrappee. This is the opposite of Wrapper which tries to be
* completely transparent.
*
* NB: Currently, only a few ProxyHandler operations are overridden to deny
* access, relying on derived SecurityWrapper to block access when necessary.
*/
template <class Base>
class JS_FRIEND_API(SecurityWrapper) : public Base
{
public:
explicit constexpr SecurityWrapper(unsigned flags, bool hasPrototype = false)
: Base(flags, hasPrototype, /* hasSecurityPolicy = */ true)
{ }
virtual bool enter(JSContext* cx, HandleObject wrapper, HandleId id, Wrapper::Action act,
bool mayThrow, bool* bp) const override;
virtual bool defineProperty(JSContext* cx, HandleObject wrapper, HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, HandleObject wrapper, bool* extensible) const override;
virtual bool preventExtensions(JSContext* cx, HandleObject wrapper,
ObjectOpResult& result) const override;
virtual bool setPrototype(JSContext* cx, HandleObject proxy, HandleObject proto,
ObjectOpResult& result) const override;
virtual bool setImmutablePrototype(JSContext* cx, HandleObject proxy, bool* succeeded) const override;
virtual bool nativeCall(JSContext* cx, IsAcceptableThis test, NativeImpl impl,
const CallArgs& args) const override;
virtual bool getBuiltinClass(JSContext* cx, HandleObject wrapper, ESClass* cls) const override;
virtual bool isArray(JSContext* cx, HandleObject wrapper, JS::IsArrayAnswer* answer) const override;
virtual bool regexp_toShared(JSContext* cx, HandleObject proxy, RegExpGuard* g) const override;
virtual bool boxedValue_unbox(JSContext* cx, HandleObject proxy, MutableHandleValue vp) const override;
// Allow isCallable and isConstructor. They used to be class-level, and so could not be guarded
// against.
virtual bool watch(JSContext* cx, JS::HandleObject proxy, JS::HandleId id,
JS::HandleObject callable) const override;
virtual bool unwatch(JSContext* cx, JS::HandleObject proxy, JS::HandleId id) const override;
/*
* Allow our subclasses to select the superclass behavior they want without
* needing to specify an exact superclass.
*/
typedef Base Permissive;
typedef SecurityWrapper<Base> Restrictive;
};
typedef SecurityWrapper<CrossCompartmentWrapper> CrossCompartmentSecurityWrapper;
extern JSObject*
TransparentObjectWrapper(JSContext* cx, HandleObject existing, HandleObject obj);
inline bool
IsWrapper(JSObject* obj)
{
return IsProxy(obj) && GetProxyHandler(obj)->family() == &Wrapper::family;
}
// Given a JSObject, returns that object stripped of wrappers. If
// stopAtWindowProxy is true, then this returns the WindowProxy if it was
// previously wrapped. Otherwise, this returns the first object for
// which JSObject::isWrapper returns false.
JS_FRIEND_API(JSObject*)
UncheckedUnwrap(JSObject* obj, bool stopAtWindowProxy = true, unsigned* flagsp = nullptr);
// Given a JSObject, returns that object stripped of wrappers. At each stage,
// the security wrapper has the opportunity to veto the unwrap. If
// stopAtWindowProxy is true, then this returns the WindowProxy if it was
// previously wrapped.
JS_FRIEND_API(JSObject*)
CheckedUnwrap(JSObject* obj, bool stopAtWindowProxy = true);
// Unwrap only the outermost security wrapper, with the same semantics as
// above. This is the checked version of Wrapper::wrappedObject.
JS_FRIEND_API(JSObject*)
UnwrapOneChecked(JSObject* obj, bool stopAtWindowProxy = true);
void
ReportAccessDenied(JSContext* cx);
JS_FRIEND_API(bool)
IsCrossCompartmentWrapper(JSObject* obj);
JS_FRIEND_API(void)
NukeCrossCompartmentWrapper(JSContext* cx, JSObject* wrapper);
void
RemapWrapper(JSContext* cx, JSObject* wobj, JSObject* newTarget);
JS_FRIEND_API(bool)
RemapAllWrappersForObject(JSContext* cx, JSObject* oldTarget,
JSObject* newTarget);
// API to recompute all cross-compartment wrappers whose source and target
// match the given filters.
JS_FRIEND_API(bool)
RecomputeWrappers(JSContext* cx, const CompartmentFilter& sourceFilter,
const CompartmentFilter& targetFilter);
} /* namespace js */
#endif /* jswrapper_h */
