gecko/js/src/jswrapper.h

267 lines
12 KiB
C++

/* -*- 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 "jsproxy.h"
namespace js {
class DummyFrameGuard;
/*
* 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) {
JS_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 instrument
* the trap operations in various ways. A wrapper is distinct from a Direct Proxy
* Handler in the sense that it can be "unwrapped" in C++, exposing the underlying
* object (Direct Proxy Handlers have an underlying target object, but don't
* expect to expose this object via any kind of unwrapping operation). Callers
* should be careful to avoid unwrapping security wrappers in the wrong context.
*/
class JS_FRIEND_API(Wrapper) : public DirectProxyHandler
{
unsigned mFlags;
public:
using BaseProxyHandler::Action;
enum Flags {
CROSS_COMPARTMENT = 1 << 0,
LAST_USED_FLAG = CROSS_COMPARTMENT
};
virtual bool defaultValue(JSContext *cx, HandleObject obj, JSType hint,
MutableHandleValue vp) const MOZ_OVERRIDE;
static JSObject *New(JSContext *cx, JSObject *obj, JSObject *parent, const Wrapper *handler,
const WrapperOptions &options = WrapperOptions());
static JSObject *Renew(JSContext *cx, JSObject *existing, JSObject *obj, const Wrapper *handler);
static const Wrapper *wrapperHandler(JSObject *wrapper);
static JSObject *wrappedObject(JSObject *wrapper);
unsigned flags() const {
return mFlags;
}
explicit MOZ_CONSTEXPR Wrapper(unsigned aFlags, bool aHasPrototype = false,
bool aHasSecurityPolicy = false)
: DirectProxyHandler(&family, aHasPrototype, aHasSecurityPolicy),
mFlags(aFlags)
{ }
virtual bool finalizeInBackground(Value priv) const MOZ_OVERRIDE;
virtual bool isConstructor(JSObject *obj) const MOZ_OVERRIDE;
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 MOZ_CONSTEXPR CrossCompartmentWrapper(unsigned aFlags, bool aHasPrototype = false,
bool aHasSecurityPolicy = false)
: Wrapper(CROSS_COMPARTMENT | aFlags, aHasPrototype, aHasSecurityPolicy)
{ }
/* ES5 Harmony fundamental wrapper traps. */
virtual bool preventExtensions(JSContext *cx, HandleObject wrapper) const MOZ_OVERRIDE;
virtual bool getPropertyDescriptor(JSContext *cx, HandleObject wrapper, HandleId id,
MutableHandle<JSPropertyDescriptor> desc) const MOZ_OVERRIDE;
virtual bool getOwnPropertyDescriptor(JSContext *cx, HandleObject wrapper, HandleId id,
MutableHandle<JSPropertyDescriptor> desc) const MOZ_OVERRIDE;
virtual bool defineProperty(JSContext *cx, HandleObject wrapper, HandleId id,
MutableHandle<JSPropertyDescriptor> desc) const MOZ_OVERRIDE;
virtual bool getOwnPropertyNames(JSContext *cx, HandleObject wrapper,
AutoIdVector &props) const MOZ_OVERRIDE;
virtual bool delete_(JSContext *cx, HandleObject wrapper, HandleId id, bool *bp) const MOZ_OVERRIDE;
virtual bool enumerate(JSContext *cx, HandleObject wrapper, AutoIdVector &props) const MOZ_OVERRIDE;
/* ES5 Harmony derived wrapper traps. */
virtual bool has(JSContext *cx, HandleObject wrapper, HandleId id, bool *bp) const MOZ_OVERRIDE;
virtual bool hasOwn(JSContext *cx, HandleObject wrapper, HandleId id, bool *bp) const MOZ_OVERRIDE;
virtual bool get(JSContext *cx, HandleObject wrapper, HandleObject receiver,
HandleId id, MutableHandleValue vp) const MOZ_OVERRIDE;
virtual bool set(JSContext *cx, HandleObject wrapper, HandleObject receiver,
HandleId id, bool strict, MutableHandleValue vp) const MOZ_OVERRIDE;
virtual bool keys(JSContext *cx, HandleObject wrapper, AutoIdVector &props) const MOZ_OVERRIDE;
virtual bool iterate(JSContext *cx, HandleObject wrapper, unsigned flags,
MutableHandleValue vp) const MOZ_OVERRIDE;
/* Spidermonkey extensions. */
virtual bool isExtensible(JSContext *cx, HandleObject wrapper, bool *extensible) const MOZ_OVERRIDE;
virtual bool call(JSContext *cx, HandleObject wrapper, const CallArgs &args) const MOZ_OVERRIDE;
virtual bool construct(JSContext *cx, HandleObject wrapper, const CallArgs &args) const MOZ_OVERRIDE;
virtual bool nativeCall(JSContext *cx, IsAcceptableThis test, NativeImpl impl,
CallArgs args) const MOZ_OVERRIDE;
virtual bool hasInstance(JSContext *cx, HandleObject wrapper, MutableHandleValue v,
bool *bp) const MOZ_OVERRIDE;
virtual const char *className(JSContext *cx, HandleObject proxy) const MOZ_OVERRIDE;
virtual JSString *fun_toString(JSContext *cx, HandleObject wrapper,
unsigned indent) const MOZ_OVERRIDE;
virtual bool regexp_toShared(JSContext *cx, HandleObject proxy, RegExpGuard *g) const MOZ_OVERRIDE;
virtual bool boxedValue_unbox(JSContext *cx, HandleObject proxy, MutableHandleValue vp) const MOZ_OVERRIDE;
virtual bool defaultValue(JSContext *cx, HandleObject wrapper, JSType hint,
MutableHandleValue vp) const MOZ_OVERRIDE;
virtual bool getPrototypeOf(JSContext *cx, HandleObject proxy,
MutableHandleObject protop) const MOZ_OVERRIDE;
virtual bool setPrototypeOf(JSContext *cx, HandleObject proxy, HandleObject proto,
bool *bp) const MOZ_OVERRIDE;
static const CrossCompartmentWrapper singleton;
static const CrossCompartmentWrapper singletonWithPrototype;
};
/*
* 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 MOZ_CONSTEXPR SecurityWrapper(unsigned flags, bool hasPrototype = false)
: Base(flags, hasPrototype, /* hasSecurityPolicy = */ true)
{ }
virtual bool isExtensible(JSContext *cx, HandleObject wrapper, bool *extensible) const MOZ_OVERRIDE;
virtual bool preventExtensions(JSContext *cx, HandleObject wrapper) const MOZ_OVERRIDE;
virtual bool enter(JSContext *cx, HandleObject wrapper, HandleId id, Wrapper::Action act,
bool *bp) const MOZ_OVERRIDE;
virtual bool nativeCall(JSContext *cx, IsAcceptableThis test, NativeImpl impl,
CallArgs args) const MOZ_OVERRIDE;
virtual bool defaultValue(JSContext *cx, HandleObject wrapper, JSType hint,
MutableHandleValue vp) const MOZ_OVERRIDE;
virtual bool objectClassIs(HandleObject obj, ESClassValue classValue,
JSContext *cx) const MOZ_OVERRIDE;
virtual bool regexp_toShared(JSContext *cx, HandleObject proxy, RegExpGuard *g) const MOZ_OVERRIDE;
virtual bool boxedValue_unbox(JSContext *cx, HandleObject proxy, MutableHandleValue vp) const MOZ_OVERRIDE;
virtual bool defineProperty(JSContext *cx, HandleObject wrapper, HandleId id,
MutableHandle<JSPropertyDescriptor> desc) const MOZ_OVERRIDE;
virtual bool setPrototypeOf(JSContext *cx, HandleObject proxy, HandleObject proto,
bool *bp) const MOZ_OVERRIDE;
virtual bool watch(JSContext *cx, JS::HandleObject proxy, JS::HandleId id,
JS::HandleObject callable) const MOZ_OVERRIDE;
virtual bool unwatch(JSContext *cx, JS::HandleObject proxy, JS::HandleId id) const MOZ_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<Wrapper> SameCompartmentSecurityWrapper;
typedef SecurityWrapper<CrossCompartmentWrapper> CrossCompartmentSecurityWrapper;
extern JSObject *
TransparentObjectWrapper(JSContext *cx, HandleObject existing, HandleObject obj,
HandleObject parent);
inline bool
IsWrapper(JSObject *obj)
{
return IsProxy(obj) && GetProxyHandler(obj)->family() == &Wrapper::family;
}
// Given a JSObject, returns that object stripped of wrappers. If
// stopAtOuter is true, then this returns the outer window 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 stopAtOuter = 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. Since checked
// code should never be unwrapping outer window wrappers, we always stop at
// outer windows.
JS_FRIEND_API(JSObject *)
CheckedUnwrap(JSObject *obj, bool stopAtOuter = 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 stopAtOuter = true);
JS_FRIEND_API(bool)
IsCrossCompartmentWrapper(JSObject *obj);
void
NukeCrossCompartmentWrapper(JSContext *cx, JSObject *wrapper);
bool
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 */