dom/bindings/RemoteObjectProxy.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "RemoteObjectProxy.h"
   8 #include "AccessCheck.h"
   9 #include "jsfriendapi.h"
  10 #include "js/Object.h"  // JS::GetClass
  11 #include "xpcprivate.h"
  12
  13 namespace mozilla::dom {
  14
  15 bool RemoteObjectProxyBase::getOwnPropertyDescriptor(
  16     JSContext* aCx, JS::Handle<JSObject*> aProxy, JS::Handle<jsid> aId,
  17     JS::MutableHandle<Maybe<JS::PropertyDescriptor>> aDesc) const {
  18   bool ok = CrossOriginGetOwnPropertyHelper(aCx, aProxy, aId, aDesc);
  19   if (!ok || aDesc.isSome()) {
  20     return ok;
  21   }
  22
  23   return CrossOriginPropertyFallback(aCx, aProxy, aId, aDesc);
  24 }
  25
  26 bool RemoteObjectProxyBase::defineProperty(
  27     JSContext* aCx, JS::Handle<JSObject*> aProxy, JS::Handle<jsid> aId,
  28     JS::Handle<JS::PropertyDescriptor> aDesc,
  29     JS::ObjectOpResult& aResult) const {
  30   // https://html.spec.whatwg.org/multipage/browsers.html#windowproxy-defineownproperty
  31   // step 3 and
  32   // https://html.spec.whatwg.org/multipage/browsers.html#location-defineownproperty
  33   // step 2
  34   return ReportCrossOriginDenial(aCx, aId, "define"_ns);
  35 }
  36
  37 bool RemoteObjectProxyBase::ownPropertyKeys(
  38     JSContext* aCx, JS::Handle<JSObject*> aProxy,
  39     JS::MutableHandleVector<jsid> aProps) const {
  40   // https://html.spec.whatwg.org/multipage/browsers.html#crossoriginownpropertykeys-(-o-)
  41   // step 2 and
  42   // https://html.spec.whatwg.org/multipage/browsers.html#crossoriginproperties-(-o-)
  43   JS::Rooted<JSObject*> holder(aCx);
  44   if (!EnsureHolder(aCx, aProxy, &holder) ||
  45       !js::GetPropertyKeys(aCx, holder,
  46                            JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS,
  47                            aProps)) {
  48     return false;
  49   }
  50
  51   // https://html.spec.whatwg.org/multipage/browsers.html#crossoriginownpropertykeys-(-o-)
  52   // step 3 and 4
  53   return xpc::AppendCrossOriginWhitelistedPropNames(aCx, aProps);
  54 }
  55
  56 bool RemoteObjectProxyBase::delete_(JSContext* aCx,
  57                                     JS::Handle<JSObject*> aProxy,
  58                                     JS::Handle<jsid> aId,
  59                                     JS::ObjectOpResult& aResult) const {
  60   // https://html.spec.whatwg.org/multipage/browsers.html#windowproxy-delete
  61   // step 3 and
  62   // https://html.spec.whatwg.org/multipage/browsers.html#location-delete step 2
  63   return ReportCrossOriginDenial(aCx, aId, "delete"_ns);
  64 }
  65
  66 bool RemoteObjectProxyBase::getPrototypeIfOrdinary(
  67     JSContext* aCx, JS::Handle<JSObject*> aProxy, bool* aIsOrdinary,
  68     JS::MutableHandle<JSObject*> aProtop) const {
  69   // WindowProxy's and Location's [[GetPrototypeOf]] traps aren't the ordinary
  70   // definition:
  71   //
  72   //   https://html.spec.whatwg.org/multipage/browsers.html#windowproxy-getprototypeof
  73   //   https://html.spec.whatwg.org/multipage/browsers.html#location-getprototypeof
  74   //
  75   // We nonetheless can implement it with a static [[Prototype]], because the
  76   // [[GetPrototypeOf]] trap should always return null.
  77   *aIsOrdinary = true;
  78   aProtop.set(nullptr);
  79   return true;
  80 }
  81
  82 bool RemoteObjectProxyBase::preventExtensions(
  83     JSContext* aCx, JS::Handle<JSObject*> aProxy,
  84     JS::ObjectOpResult& aResult) const {
  85   // https://html.spec.whatwg.org/multipage/browsers.html#windowproxy-preventextensions
  86   // and
  87   // https://html.spec.whatwg.org/multipage/browsers.html#location-preventextensions
  88   return aResult.failCantPreventExtensions();
  89 }
  90
  91 bool RemoteObjectProxyBase::isExtensible(JSContext* aCx,
  92                                          JS::Handle<JSObject*> aProxy,
  93                                          bool* aExtensible) const {
  94   // https://html.spec.whatwg.org/multipage/browsers.html#windowproxy-isextensible
  95   // and
  96   // https://html.spec.whatwg.org/multipage/browsers.html#location-isextensible
  97   *aExtensible = true;
  98   return true;
  99 }
 100
 101 bool RemoteObjectProxyBase::get(JSContext* aCx, JS::Handle<JSObject*> aProxy,
 102                                 JS::Handle<JS::Value> aReceiver,
 103                                 JS::Handle<jsid> aId,
 104                                 JS::MutableHandle<JS::Value> aVp) const {
 105   return CrossOriginGet(aCx, aProxy, aReceiver, aId, aVp);
 106 }
 107
 108 bool RemoteObjectProxyBase::set(JSContext* aCx, JS::Handle<JSObject*> aProxy,
 109                                 JS::Handle<jsid> aId,
 110                                 JS::Handle<JS::Value> aValue,
 111                                 JS::Handle<JS::Value> aReceiver,
 112                                 JS::ObjectOpResult& aResult) const {
 113   return CrossOriginSet(aCx, aProxy, aId, aValue, aReceiver, aResult);
 114 }
 115
 116 bool RemoteObjectProxyBase::getOwnEnumerablePropertyKeys(
 117     JSContext* aCx, JS::Handle<JSObject*> aProxy,
 118     JS::MutableHandleVector<jsid> aProps) const {
 119   return true;
 120 }
 121
 122 const char* RemoteObjectProxyBase::className(
 123     JSContext* aCx, JS::Handle<JSObject*> aProxy) const {
 124   MOZ_ASSERT(js::IsProxy(aProxy));
 125
 126   return NamesOfInterfacesWithProtos(mPrototypeID);
 127 }
 128
 129 void RemoteObjectProxyBase::GetOrCreateProxyObject(
 130     JSContext* aCx, void* aNative, const JSClass* aClasp,
 131     JS::Handle<JSObject*> aTransplantTo, JS::MutableHandle<JSObject*> aProxy,
 132     bool& aNewObjectCreated) const {
 133   xpc::CompartmentPrivate* priv =
 134       xpc::CompartmentPrivate::Get(JS::CurrentGlobalOrNull(aCx));
 135   xpc::CompartmentPrivate::RemoteProxyMap& map = priv->GetRemoteProxyMap();
 136   if (auto result = map.lookup(aNative)) {
 137     MOZ_RELEASE_ASSERT(!aTransplantTo,
 138                        "GOCPO failed by finding an existing value");
 139
 140     aProxy.set(result->value());
 141
 142     // During a transplant, we put an object that is temporarily not a
 143     // proxy object into the map. Make sure that we don't return one of
 144     // these objects in the middle of a transplant.
 145     MOZ_RELEASE_ASSERT(JS::GetClass(aProxy) == aClasp);
 146
 147     return;
 148   }
 149
 150   js::ProxyOptions options;
 151   options.setClass(aClasp);
 152   JS::Rooted<JS::Value> native(aCx, JS::PrivateValue(aNative));
 153   JS::Rooted<JSObject*> obj(
 154       aCx, js::NewProxyObject(aCx, this, native, nullptr, options));
 155   if (!obj) {
 156     MOZ_RELEASE_ASSERT(!aTransplantTo, "GOCPO failed at NewProxyObject");
 157     return;
 158   }
 159
 160   bool success;
 161   if (!JS_SetImmutablePrototype(aCx, obj, &success)) {
 162     MOZ_RELEASE_ASSERT(!aTransplantTo,
 163                        "GOCPO failed at JS_SetImmutablePrototype");
 164     return;
 165   }
 166   MOZ_ASSERT(success);
 167
 168   aNewObjectCreated = true;
 169
 170   // If we're transplanting onto an object, we want to make sure that it does
 171   // not have the same class as aClasp to ensure that the release assert earlier
 172   // in this function will actually fire if we try to return a proxy object in
 173   // the middle of a transplant.
 174   MOZ_RELEASE_ASSERT(!aTransplantTo || (JS::GetClass(aTransplantTo) != aClasp),
 175                      "GOCPO failed by not changing the class");
 176
 177   if (!map.put(aNative, aTransplantTo ? aTransplantTo : obj)) {
 178     MOZ_RELEASE_ASSERT(!aTransplantTo, "GOCPO failed at map.put");
 179     return;
 180   }
 181
 182   aProxy.set(obj);
 183 }
 184
 185 const char RemoteObjectProxyBase::sCrossOriginProxyFamily = 0;
 186
 187 }  // namespace mozilla::dom