gecko-dev/dom/base/MaybeCrossOriginObject.h

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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 mozilla_dom_MaybeCrossOriginObject_h
#define mozilla_dom_MaybeCrossOriginObject_h
/**
* Shared infrastructure for WindowProxy and Location objects. These
* are the objects that can be accessed cross-origin in the HTML
* specification.
*
* This class can be inherited from by the relevant proxy handlers to
* help implement spec algorithms.
*
* The algorithms this class implements come from
* <https://html.spec.whatwg.org/multipage/browsers.html#shared-abstract-operations>,
* <https://html.spec.whatwg.org/multipage/window-object.html#the-windowproxy-exotic-object>,
* and
* <https://html.spec.whatwg.org/multipage/history.html#the-location-interface>.
*
* The class is templated on its base so we can directly implement the things
* that should have identical implementations for WindowProxy and Location. The
* templating is needed because WindowProxy needs to be a wrapper and Location
* shouldn't be one.
*/
#include "js/Class.h"
#include "js/TypeDecls.h"
#include "nsStringFwd.h"
#include "mozilla/Maybe.h"
namespace mozilla::dom {
/**
* "mAttributes" and "mMethods" are the cross-origin attributes and methods we
* care about, which should get defined on holders.
*
* "mChromeOnlyAttributes" and "mChromeOnlyMethods" are the cross-origin
* attributes and methods we care about, which should get defined on holders
* for the chrome realm, in addition to the properties that are in
* "mAttributes" and "mMethods".
*/
struct CrossOriginProperties {
const JSPropertySpec* mAttributes;
const JSFunctionSpec* mMethods;
const JSPropertySpec* mChromeOnlyAttributes;
const JSFunctionSpec* mChromeOnlyMethods;
};
// Methods that MaybeCrossOriginObject wants that do not depend on the "Base"
// template parameter. We can avoid having multiple instantiations of them by
// pulling them out into this helper class.
class MaybeCrossOriginObjectMixins {
public:
/**
* Implementation of
* <https://html.spec.whatwg.org/multipage/browsers.html#isplatformobjectsameorigin-(-o-)>.
* "cx" and "obj" may or may not be same-compartment and even when
* same-compartment may not be same-Realm. "obj" can be a WindowProxy, a
* Window, or a Location.
*/
static bool IsPlatformObjectSameOrigin(JSContext* cx, JSObject* obj);
protected:
/**
* Implementation of
* <https://html.spec.whatwg.org/multipage/browsers.html#crossorigingetownpropertyhelper-(-o,-p-)>.
*
* "cx" and "obj" are expected to be different-Realm here, and may be
* different-compartment. "obj" can be a "WindowProxy" or a "Location" or a
* cross-process proxy for one of those.
*/
bool CrossOriginGetOwnPropertyHelper(
JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id,
JS::MutableHandle<Maybe<JS::PropertyDescriptor>> desc) const;
/**
* Implementation of
* <https://html.spec.whatwg.org/multipage/browsers.html#crossoriginpropertyfallback-(-p-)>.
*
* This should be called at the end of getOwnPropertyDescriptor
* methods in the cross-origin case.
*
* "cx" and "obj" are expected to be different-Realm here, and may
* be different-compartment. "obj" can be a "WindowProxy" or a
* "Location" or a cross-process proxy for one of those.
*/
static bool CrossOriginPropertyFallback(
JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id,
JS::MutableHandle<Maybe<JS::PropertyDescriptor>> desc);
/**
* Implementation of
* <https://html.spec.whatwg.org/multipage/browsers.html#crossoriginget-(-o,-p,-receiver-)>.
*
* "cx" and "obj" are expected to be different-Realm here and may be
* different-compartment. "obj" can be a "WindowProxy" or a
* "Location" or a cross-process proxy for one of those.
*
* "receiver" will be in the compartment of "cx". The return value will
* be in the compartment of "cx".
*/
static bool CrossOriginGet(JSContext* cx, JS::Handle<JSObject*> obj,
JS::Handle<JS::Value> receiver,
JS::Handle<jsid> id,
JS::MutableHandle<JS::Value> vp);
/**
* Implementation of
* <https://html.spec.whatwg.org/multipage/browsers.html#crossoriginset-(-o,-p,-v,-receiver-)>.
*
* "cx" and "obj" are expected to be different-Realm here and may be
* different-compartment. "obj" can be a "WindowProxy" or a
* "Location" or a cross-process proxy for one of those.
*
* "receiver" and "v" will be in the compartment of "cx".
*/
static bool CrossOriginSet(JSContext* cx, JS::Handle<JSObject*> obj,
JS::Handle<jsid> id, JS::Handle<JS::Value> v,
JS::Handle<JS::Value> receiver,
JS::ObjectOpResult& result);
/**
* Utility method to ensure a holder for cross-origin properties for the
* current global of the JSContext.
*
* When this is called, "cx" and "obj" are _always_ different-Realm, because
* this is only used in cross-origin situations. The "holder" return value is
* always in the Realm of "cx".
*
* "obj" is the object which has space to store the collection of holders in
* the given slot.
*
* "properties" are the cross-origin attributes and methods we care about,
* which should get defined on holders.
*/
static bool EnsureHolder(JSContext* cx, JS::Handle<JSObject*> obj,
size_t slot, const CrossOriginProperties& properties,
JS::MutableHandle<JSObject*> holder);
/**
* Ensures we have a holder object for the current Realm. When this is
* called, "obj" is guaranteed to not be same-Realm with "cx", because this
* is only used for cross-origin cases.
*
* Subclasses are expected to implement this by calling our static
* EnsureHolder with the appropriate arguments.
*/
virtual bool EnsureHolder(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::MutableHandle<JSObject*> holder) const = 0;
/**
* Report a cross-origin denial for a property named by aId. Always
* returns false, so it can be used as "return
* ReportCrossOriginDenial(...);".
*/
static bool ReportCrossOriginDenial(JSContext* aCx, JS::Handle<jsid> aId,
const nsACString& aAccessType);
};
// A proxy handler for objects that may be cross-origin objects. Whether they
// actually _are_ cross-origin objects can change dynamically if document.domain
// is set.
template <typename Base>
class MaybeCrossOriginObject : public Base,
public MaybeCrossOriginObjectMixins {
protected:
template <typename... Args>
constexpr MaybeCrossOriginObject(Args&&... aArgs)
: Base(std::forward<Args>(aArgs)...) {}
/**
* Implementation of [[GetPrototypeOf]] as defined in
* <https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-getprototypeof>
* and
* <https://html.spec.whatwg.org/multipage/history.html#location-getprototypeof>.
*
* Our prototype-storage model looks quite different from the spec's, so we
* need to implement some hooks that don't directly map to the spec.
*
* "proxy" is the WindowProxy or Location involved. It may or may not be
* same-compartment with cx.
*
* "protop" is the prototype value (possibly null). It is guaranteed to be
* same-compartment with cx after this function returns successfully.
*/
bool getPrototype(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::MutableHandle<JSObject*> protop) const final;
/**
* Hook for doing the OrdinaryGetPrototypeOf bits that [[GetPrototypeOf]] does
* in the spec. Location and WindowProxy store that information somewhat
* differently.
*
* The prototype should come from the Realm of "cx".
*/
virtual JSObject* getSameOriginPrototype(JSContext* cx) const = 0;
/**
* Implementation of [[SetPrototypeOf]] as defined in
* <https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-setprototypeof>
* and
* <https://html.spec.whatwg.org/multipage/history.html#location-setprototypeof>.
*
* "proxy" is the WindowProxy or Location object involved. It may or may not
* be same-compartment with "cx".
*
* "proto" is the new prototype object (possibly null). It must be
* same-compartment with "cx".
*/
bool setPrototype(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<JSObject*> proto,
JS::ObjectOpResult& result) const final;
/**
* Our non-standard getPrototypeIfOrdinary hook.
*/
bool getPrototypeIfOrdinary(JSContext* cx, JS::Handle<JSObject*> proxy,
bool* isOrdinary,
JS::MutableHandle<JSObject*> protop) const final;
/**
* Our non-standard setImmutablePrototype hook.
*/
bool setImmutablePrototype(JSContext* cx, JS::Handle<JSObject*> proxy,
bool* succeeded) const final;
/**
* Implementation of [[IsExtensible]] as defined in
* <https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-isextensible>
* and
* <https://html.spec.whatwg.org/multipage/history.html#location-isextensible>.
*/
bool isExtensible(JSContext* cx, JS::Handle<JSObject*> proxy,
bool* extensible) const final;
/**
* Implementation of [[PreventExtensions]] as defined in
* <https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-preventextensions>
* and
* <https://html.spec.whatwg.org/multipage/history.html#location-preventextensions>.
*/
bool preventExtensions(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::ObjectOpResult& result) const final;
/**
* Implementation of [[GetOwnProperty]] is completely delegated to subclasses.
*
* "proxy" is the WindowProxy or Location object involved. It may or may not
* be same-compartment with cx.
*/
bool getOwnPropertyDescriptor(
JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::MutableHandle<Maybe<JS::PropertyDescriptor>> desc) const override = 0;
/**
* Implementation of [[DefineOwnProperty]] as defined in
* <https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-defineownproperty>
* and
* <https://html.spec.whatwg.org/multipage/history.html#location-defineownproperty>.
* "proxy" is the WindowProxy or Location object involved. It may or may not
* be same-compartment with cx.
*
*/
bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result) const final;
/**
* Some of our base classes define _another_ virtual defineProperty, and we
* get overloaded-virtual warnings as a result due to us hiding it, if we
* don't pull it in here.
*/
using Base::defineProperty;
/**
* Hook for handling the same-origin case in defineProperty.
*
* "proxy" is the WindowProxy or Location object involved. It will be
* same-compartment with cx.
*
* "desc" is a the descriptor being defined. It will be same-compartment with
* cx.
*/
virtual bool definePropertySameOrigin(JSContext* cx,
JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result) const = 0;
/**
* Implementation of [[Get]] is completely delegated to subclasses.
*
* "proxy" is the WindowProxy or Location object involved. It may or may not
* be same-compartment with "cx".
*
* "receiver" is the receiver ("this") for the get. It will be
* same-compartment with "cx"
*
* "vp" is the return value. It will be same-compartment with "cx".
*/
bool get(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<JS::Value> receiver, JS::Handle<jsid> id,
JS::MutableHandle<JS::Value> vp) const override = 0;
/**
* Implementation of [[Set]] is completely delegated to subclasses.
*
* "proxy" is the WindowProxy or Location object involved. It may or may not
* be same-compartment with "cx".
*
* "v" is the value being set. It will be same-compartment with "cx".
*
* "receiver" is the receiver ("this") for the set. It will be
* same-compartment with "cx".
*/
bool set(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::Handle<JS::Value> v, JS::Handle<JS::Value> receiver,
JS::ObjectOpResult& result) const override = 0;
/**
* Implementation of [[Delete]] is completely delegated to subclasses.
*
* "proxy" is the WindowProxy or Location object involved. It may or may not
* be same-compartment with "cx".
*/
bool delete_(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::ObjectOpResult& result) const override = 0;
/**
* Spidermonkey-internal hook for enumerating objects.
*/
bool enumerate(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::MutableHandleVector<jsid> props) const final;
// Cross origin objects should not participate in private fields.
virtual bool throwOnPrivateField() const override { return true; }
/**
* Spidermonkey-internal hook used by Object.prototype.toString. Subclasses
* need to implement this, because we don't know what className they want.
* Except in the cross-origin case, when we could maybe handle it...
*/
const char* className(JSContext* cx,
JS::Handle<JSObject*> proxy) const override = 0;
};
} // namespace mozilla::dom
#endif /* mozilla_dom_MaybeCrossOriginObject_h */