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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef js_Wrapper_h
#define js_Wrapper_h
#include "mozilla/Attributes.h"
#include "js/Proxy.h"
namespace js {
struct CompartmentFilter;
/*
* 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_;
};
// Base class for proxy handlers that want to forward all operations to an
// object stored in the proxy's private slot.
class JS_PUBLIC_API ForwardingProxyHandler : public BaseProxyHandler {
public:
using BaseProxyHandler::BaseProxyHandler;
/* Standard internal methods. */
virtual bool getOwnPropertyDescriptor(
JSContext* cx, JS::HandleObject proxy, JS::HandleId id,
JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> desc)
const override;
virtual bool defineProperty(JSContext* cx, JS::HandleObject proxy,
JS::HandleId id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result) const override;
virtual bool ownPropertyKeys(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleIdVector props) const override;
virtual bool delete_(JSContext* cx, JS::HandleObject proxy, JS::HandleId id,
JS::ObjectOpResult& result) const override;
virtual bool enumerate(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleIdVector props) const override;
virtual bool getPrototype(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleObject protop) const override;
virtual bool setPrototype(JSContext* cx, JS::HandleObject proxy,
JS::HandleObject proto,
JS::ObjectOpResult& result) const override;
virtual bool getPrototypeIfOrdinary(
JSContext* cx, JS::HandleObject proxy, bool* isOrdinary,
JS::MutableHandleObject protop) const override;
virtual bool setImmutablePrototype(JSContext* cx, JS::HandleObject proxy,
bool* succeeded) const override;
virtual bool preventExtensions(JSContext* cx, JS::HandleObject proxy,
JS::ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, JS::HandleObject proxy,
bool* extensible) const override;
virtual bool has(JSContext* cx, JS::HandleObject proxy, JS::HandleId id,
bool* bp) const override;
virtual bool get(JSContext* cx, JS::HandleObject proxy,
JS::HandleValue receiver, JS::HandleId id,
JS::MutableHandleValue vp) const override;
virtual bool set(JSContext* cx, JS::HandleObject proxy, JS::HandleId id,
JS::HandleValue v, JS::HandleValue receiver,
JS::ObjectOpResult& result) const override;
virtual bool call(JSContext* cx, JS::HandleObject proxy,
const JS::CallArgs& args) const override;
virtual bool construct(JSContext* cx, JS::HandleObject proxy,
const JS::CallArgs& args) const override;
/* SpiderMonkey extensions. */
virtual bool hasOwn(JSContext* cx, JS::HandleObject proxy, JS::HandleId id,
bool* bp) const override;
virtual bool getOwnEnumerablePropertyKeys(
JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleIdVector props) const override;
virtual bool nativeCall(JSContext* cx, JS::IsAcceptableThis test,
JS::NativeImpl impl,
const JS::CallArgs& args) const override;
virtual bool hasInstance(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleValue v, bool* bp) const override;
virtual bool getBuiltinClass(JSContext* cx, JS::HandleObject proxy,
ESClass* cls) const override;
virtual bool isArray(JSContext* cx, JS::HandleObject proxy,
JS::IsArrayAnswer* answer) const override;
virtual const char* className(JSContext* cx,
JS::HandleObject proxy) const override;
virtual JSString* fun_toString(JSContext* cx, JS::HandleObject proxy,
bool isToSource) const override;
virtual RegExpShared* regexp_toShared(JSContext* cx,
JS::HandleObject proxy) const override;
virtual bool boxedValue_unbox(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleValue vp) const override;
virtual bool isCallable(JSObject* obj) const override;
virtual bool isConstructor(JSObject* obj) const override;
// Use the target object for private fields.
virtual bool useProxyExpandoObjectForPrivateFields() const override {
return false;
}
};
/*
* 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_PUBLIC_API Wrapper : public ForwardingProxyHandler {
unsigned mFlags;
public:
explicit constexpr Wrapper(unsigned aFlags, bool aHasPrototype = false,
bool aHasSecurityPolicy = false)
: ForwardingProxyHandler(&family, aHasPrototype, aHasSecurityPolicy),
mFlags(aFlags) {}
virtual bool finalizeInBackground(const JS::Value& priv) const override;
/**
* A hook subclasses can override to implement CheckedUnwrapDynamic
* behavior. The JSContext represents the "who is trying to unwrap?" Realm.
* The JSObject is the wrapper that the caller is trying to unwrap.
*/
virtual bool dynamicCheckedUnwrapAllowed(JS::HandleObject obj,
JSContext* cx) const {
MOZ_ASSERT(hasSecurityPolicy(), "Why are you asking?");
return false;
}
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 inline const Wrapper* wrapperHandler(const JSObject* wrapper);
static JSObject* wrappedObject(JSObject* wrapper);
unsigned flags() const { return mFlags; }
bool isCrossCompartmentWrapper() const {
return !!(mFlags & CROSS_COMPARTMENT);
}
static const char family;
static const Wrapper singleton;
static const Wrapper singletonWithPrototype;
static JSObject* const defaultProto;
};
inline JSObject* WrapperOptions::proto() const {
return proto_ ? *proto_ : Wrapper::defaultProto;
}
/* Base class for all cross compartment wrapper handlers. */
class JS_PUBLIC_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, JS::HandleObject wrapper, JS::HandleId id,
JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> desc)
const override;
virtual bool defineProperty(JSContext* cx, JS::HandleObject wrapper,
JS::HandleId id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result) const override;
virtual bool ownPropertyKeys(JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleIdVector props) const override;
virtual bool delete_(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
JS::ObjectOpResult& result) const override;
virtual bool enumerate(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleIdVector props) const override;
virtual bool getPrototype(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleObject protop) const override;
virtual bool setPrototype(JSContext* cx, JS::HandleObject proxy,
JS::HandleObject proto,
JS::ObjectOpResult& result) const override;
virtual bool getPrototypeIfOrdinary(
JSContext* cx, JS::HandleObject proxy, bool* isOrdinary,
JS::MutableHandleObject protop) const override;
virtual bool setImmutablePrototype(JSContext* cx, JS::HandleObject proxy,
bool* succeeded) const override;
virtual bool preventExtensions(JSContext* cx, JS::HandleObject wrapper,
JS::ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, JS::HandleObject wrapper,
bool* extensible) const override;
virtual bool has(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
bool* bp) const override;
virtual bool get(JSContext* cx, JS::HandleObject wrapper,
JS::HandleValue receiver, JS::HandleId id,
JS::MutableHandleValue vp) const override;
virtual bool set(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
JS::HandleValue v, JS::HandleValue receiver,
JS::ObjectOpResult& result) const override;
virtual bool call(JSContext* cx, JS::HandleObject wrapper,
const JS::CallArgs& args) const override;
virtual bool construct(JSContext* cx, JS::HandleObject wrapper,
const JS::CallArgs& args) const override;
/* SpiderMonkey extensions. */
virtual bool hasOwn(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
bool* bp) const override;
virtual bool getOwnEnumerablePropertyKeys(
JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleIdVector props) const override;
virtual bool nativeCall(JSContext* cx, JS::IsAcceptableThis test,
JS::NativeImpl impl,
const JS::CallArgs& args) const override;
virtual bool hasInstance(JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleValue v, bool* bp) const override;
virtual const char* className(JSContext* cx,
JS::HandleObject proxy) const override;
virtual JSString* fun_toString(JSContext* cx, JS::HandleObject wrapper,
bool isToSource) const override;
virtual RegExpShared* regexp_toShared(JSContext* cx,
JS::HandleObject proxy) const override;
virtual bool boxedValue_unbox(JSContext* cx, JS::HandleObject proxy,
JS::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_PUBLIC_API OpaqueCrossCompartmentWrapper
: public CrossCompartmentWrapper {
public:
explicit constexpr OpaqueCrossCompartmentWrapper()
: CrossCompartmentWrapper(0) {}
/* Standard internal methods. */
virtual bool getOwnPropertyDescriptor(
JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> desc)
const override;
virtual bool defineProperty(JSContext* cx, JS::HandleObject wrapper,
JS::HandleId id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result) const override;
virtual bool ownPropertyKeys(JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleIdVector props) const override;
virtual bool delete_(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
JS::ObjectOpResult& result) const override;
virtual bool enumerate(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleIdVector props) const override;
virtual bool getPrototype(JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleObject protop) const override;
virtual bool setPrototype(JSContext* cx, JS::HandleObject wrapper,
JS::HandleObject proto,
JS::ObjectOpResult& result) const override;
virtual bool getPrototypeIfOrdinary(
JSContext* cx, JS::HandleObject wrapper, bool* isOrdinary,
JS::MutableHandleObject protop) const override;
virtual bool setImmutablePrototype(JSContext* cx, JS::HandleObject wrapper,
bool* succeeded) const override;
virtual bool preventExtensions(JSContext* cx, JS::HandleObject wrapper,
JS::ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, JS::HandleObject wrapper,
bool* extensible) const override;
virtual bool has(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
bool* bp) const override;
virtual bool get(JSContext* cx, JS::HandleObject wrapper,
JS::HandleValue receiver, JS::HandleId id,
JS::MutableHandleValue vp) const override;
virtual bool set(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
JS::HandleValue v, JS::HandleValue receiver,
JS::ObjectOpResult& result) const override;
virtual bool call(JSContext* cx, JS::HandleObject wrapper,
const JS::CallArgs& args) const override;
virtual bool construct(JSContext* cx, JS::HandleObject wrapper,
const JS::CallArgs& args) const override;
/* SpiderMonkey extensions. */
virtual bool hasOwn(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
bool* bp) const override;
virtual bool getOwnEnumerablePropertyKeys(
JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleIdVector props) const override;
virtual bool getBuiltinClass(JSContext* cx, JS::HandleObject wrapper,
ESClass* cls) const override;
virtual bool isArray(JSContext* cx, JS::HandleObject obj,
JS::IsArrayAnswer* answer) const override;
virtual bool hasInstance(JSContext* cx, JS::HandleObject wrapper,
JS::MutableHandleValue v, bool* bp) const override;
virtual const char* className(JSContext* cx,
JS::HandleObject wrapper) const override;
virtual JSString* fun_toString(JSContext* cx, JS::HandleObject proxy,
bool isToSource) 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_PUBLIC_API SecurityWrapper : public Base {
public:
explicit constexpr SecurityWrapper(unsigned flags, bool hasPrototype = false)
: Base(flags, hasPrototype, /* hasSecurityPolicy = */ true) {}
virtual bool enter(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id,
Wrapper::Action act, bool mayThrow,
bool* bp) const override;
virtual bool defineProperty(JSContext* cx, JS::HandleObject wrapper,
JS::HandleId id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result) const override;
virtual bool isExtensible(JSContext* cx, JS::HandleObject wrapper,
bool* extensible) const override;
virtual bool preventExtensions(JSContext* cx, JS::HandleObject wrapper,
JS::ObjectOpResult& result) const override;
virtual bool setPrototype(JSContext* cx, JS::HandleObject proxy,
JS::HandleObject proto,
JS::ObjectOpResult& result) const override;
virtual bool setImmutablePrototype(JSContext* cx, JS::HandleObject proxy,
bool* succeeded) const override;
virtual bool nativeCall(JSContext* cx, JS::IsAcceptableThis test,
JS::NativeImpl impl,
const JS::CallArgs& args) const override;
virtual bool getBuiltinClass(JSContext* cx, JS::HandleObject wrapper,
ESClass* cls) const override;
virtual bool isArray(JSContext* cx, JS::HandleObject wrapper,
JS::IsArrayAnswer* answer) const override;
virtual RegExpShared* regexp_toShared(JSContext* cx,
JS::HandleObject proxy) const override;
virtual bool boxedValue_unbox(JSContext* cx, JS::HandleObject proxy,
JS::MutableHandleValue vp) const override;
// Allow isCallable and isConstructor. They used to be class-level, and so
// could not be guarded against.
/*
* 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,
JS::HandleObject existing,
JS::HandleObject obj);
inline bool IsWrapper(const JSObject* obj) {
return IsProxy(obj) && GetProxyHandler(obj)->family() == &Wrapper::family;
}
inline bool IsCrossCompartmentWrapper(const JSObject* obj) {
return IsWrapper(obj) &&
(Wrapper::wrapperHandler(obj)->flags() & Wrapper::CROSS_COMPARTMENT);
}
/* static */ inline const Wrapper* Wrapper::wrapperHandler(
const JSObject* wrapper) {
MOZ_ASSERT(IsWrapper(wrapper));
return static_cast<const Wrapper*>(GetProxyHandler(wrapper));
}
// 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.
//
// ExposeToActiveJS is called on wrapper targets to allow gray marking
// assertions to work while an incremental GC is in progress, but this means
// that this cannot be called from the GC or off the main thread.
JS_PUBLIC_API JSObject* UncheckedUnwrap(JSObject* obj,
bool stopAtWindowProxy = true,
unsigned* flagsp = nullptr);
// Given a JSObject, returns that object stripped of wrappers, except
// WindowProxy wrappers. At each stage, the wrapper has the opportunity to veto
// the unwrap. Null is returned if there are security wrappers that can't be
// unwrapped.
//
// This does a static-only unwrap check: it basically checks whether _all_
// globals in the wrapper's source compartment should be able to access the
// wrapper target. This won't necessarily return the right thing for the HTML
// spec's cross-origin objects (WindowProxy and Location), but is fine to use
// when failure to unwrap one of those objects wouldn't be a problem. For
// example, if you want to test whether your target object is a specific class
// that's not WindowProxy or Location, you can use this.
//
// ExposeToActiveJS is called on wrapper targets to allow gray marking
// assertions to work while an incremental GC is in progress, but this means
// that this cannot be called from the GC or off the main thread.
JS_PUBLIC_API JSObject* CheckedUnwrapStatic(JSObject* obj);
// Unwrap only the outermost security wrapper, with the same semantics as
// above. This is the checked version of Wrapper::wrappedObject.
JS_PUBLIC_API JSObject* UnwrapOneCheckedStatic(JSObject* obj);
// 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. Null is returned if there are security wrappers that
// can't be unwrapped.
//
// ExposeToActiveJS is called on wrapper targets to allow gray marking
// assertions to work while an incremental GC is in progress, but this means
// that this cannot be called from the GC or off the main thread.
//
// The JSContext argument will be used for dynamic checks (needed by WindowProxy
// and Location) and should represent the Realm doing the unwrapping. It is not
// used to throw exceptions; this function never throws.
//
// This function may be able to GC (and the static analysis definitely thinks it
// can), but it still takes a JSObject* argument, because some of its callers
// would actually have a bit of a hard time producing a Rooted. And it ends up
// having to root internally anyway, because it wants to use the value in a loop
// and you can't assign to a HandleObject. What this means is that callers who
// plan to use the argument object after they have called this function will
// need to root it to avoid hazard failures, even though this function doesn't
// require a Handle.
JS_PUBLIC_API JSObject* CheckedUnwrapDynamic(JSObject* obj, JSContext* cx,
bool stopAtWindowProxy = true);
// Unwrap only the outermost security wrapper, with the same semantics as
// above. This is the checked version of Wrapper::wrappedObject.
JS_PUBLIC_API JSObject* UnwrapOneCheckedDynamic(JS::HandleObject obj,
JSContext* cx,
bool stopAtWindowProxy = true);
// Given a JSObject, returns that object stripped of wrappers. This returns the
// WindowProxy if it was previously wrapped.
//
// ExposeToActiveJS is not called on wrapper targets so this can be called from
// the GC or off the main thread.
JS_PUBLIC_API JSObject* UncheckedUnwrapWithoutExpose(JSObject* obj);
void ReportAccessDenied(JSContext* cx);
JS_PUBLIC_API void NukeCrossCompartmentWrapper(JSContext* cx,
JSObject* wrapper);
// If a cross-compartment wrapper source => target exists, nuke it.
JS_PUBLIC_API void NukeCrossCompartmentWrapperIfExists(JSContext* cx,
JS::Compartment* source,
JSObject* target);
void RemapWrapper(JSContext* cx, JSObject* wobj, JSObject* newTarget);
void RemapDeadWrapper(JSContext* cx, JS::HandleObject wobj,
JS::HandleObject newTarget);
JS_PUBLIC_API bool RemapAllWrappersForObject(JSContext* cx,
JS::HandleObject oldTarget,
JS::HandleObject newTarget);
// API to recompute all cross-compartment wrappers whose source and target
// match the given filters.
JS_PUBLIC_API bool RecomputeWrappers(JSContext* cx,
const CompartmentFilter& sourceFilter,
const CompartmentFilter& targetFilter);
} /* namespace js */
#endif /* js_Wrapper_h */