1 files changed, 270 insertions, 0 deletions
diff --git a/js/xpconnect/wrappers/AddonWrapper.cpp b/js/xpconnect/wrappers/AddonWrapper.cpp
new file mode 100644
index 000000000..eb1670b3a
--- /dev/null
+++ b/js/xpconnect/wrappers/AddonWrapper.cpp
@@ -0,0 +1,270 @@
+/* -*- 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/. */
+
+#include "AddonWrapper.h"
+#include "WrapperFactory.h"
+#include "XrayWrapper.h"
+#include "jsapi.h"
+#include "jsfriendapi.h"
+#include "nsIAddonInterposition.h"
+#include "xpcprivate.h"
+#include "mozilla/dom/BindingUtils.h"
+#include "nsGlobalWindow.h"
+
+#include "GeckoProfiler.h"
+
+#include "nsID.h"
+
+using namespace js;
+using namespace JS;
+
+namespace xpc {
+
+bool
+InterposeProperty(JSContext* cx, HandleObject target, const nsIID* iid, HandleId id,
+                  MutableHandle<PropertyDescriptor> descriptor)
+{
+    // We only want to do interpostion on DOM instances and
+    // wrapped natives.
+    RootedObject unwrapped(cx, UncheckedUnwrap(target));
+    const js::Class* clasp = js::GetObjectClass(unwrapped);
+    bool isCPOW = jsipc::IsWrappedCPOW(unwrapped);
+    if (!mozilla::dom::IsDOMClass(clasp) &&
+        !IS_WN_CLASS(clasp) &&
+        !IS_PROTO_CLASS(clasp) &&
+        clasp != &OuterWindowProxyClass &&
+        !isCPOW) {
+        return true;
+    }
+
+    XPCWrappedNativeScope* scope = ObjectScope(CurrentGlobalOrNull(cx));
+    MOZ_ASSERT(scope->HasInterposition());
+
+    nsCOMPtr<nsIAddonInterposition> interp = scope->GetInterposition();
+    InterpositionWhitelist* wl = XPCWrappedNativeScope::GetInterpositionWhitelist(interp);
+    // We do InterposeProperty only if the id is on the whitelist of the interpostion
+    // or if the target is a CPOW.
+    if ((!wl || !wl->has(JSID_BITS(id.get()))) && !isCPOW)
+        return true;
+
+    JSAddonId* addonId = AddonIdOfObject(target);
+    RootedValue addonIdValue(cx, StringValue(StringOfAddonId(addonId)));
+    RootedValue prop(cx, IdToValue(id));
+    RootedValue targetValue(cx, ObjectValue(*target));
+    RootedValue descriptorVal(cx);
+    nsresult rv = interp->InterposeProperty(addonIdValue, targetValue,
+                                            iid, prop, &descriptorVal);
+    if (NS_FAILED(rv)) {
+        xpc::Throw(cx, rv);
+        return false;
+    }
+
+    if (!descriptorVal.isObject())
+        return true;
+
+    // We need to be careful parsing descriptorVal. |cx| is in the compartment
+    // of the add-on and the descriptor is in the compartment of the
+    // interposition. We could wrap the descriptor in the add-on's compartment
+    // and then parse it. However, parsing the descriptor fetches properties
+    // from it, and we would try to interpose on those property accesses. So
+    // instead we parse in the interposition's compartment and then wrap the
+    // descriptor.
+
+    {
+        JSAutoCompartment ac(cx, &descriptorVal.toObject());
+        if (!JS::ObjectToCompletePropertyDescriptor(cx, target, descriptorVal, descriptor))
+            return false;
+    }
+
+    // Always make the property non-configurable regardless of what the
+    // interposition wants.
+    descriptor.setAttributes(descriptor.attributes() | JSPROP_PERMANENT);
+
+    if (!JS_WrapPropertyDescriptor(cx, descriptor))
+        return false;
+
+    return true;
+}
+
+bool
+InterposeCall(JSContext* cx, JS::HandleObject target, const JS::CallArgs& args, bool* done)
+{
+    *done = false;
+    XPCWrappedNativeScope* scope = ObjectScope(CurrentGlobalOrNull(cx));
+    MOZ_ASSERT(scope->HasInterposition());
+
+    nsCOMPtr<nsIAddonInterposition> interp = scope->GetInterposition();
+
+    RootedObject unwrappedTarget(cx, UncheckedUnwrap(target));
+    XPCWrappedNativeScope* targetScope = ObjectScope(unwrappedTarget);
+    bool hasInterpostion = targetScope->HasCallInterposition();
+
+    if (!hasInterpostion)
+        return true;
+
+    // If there is a call interpostion, we don't want to propogate the
+    // call to Base:
+    *done = true; 
+
+    JSAddonId* addonId = AddonIdOfObject(target);
+    RootedValue addonIdValue(cx, StringValue(StringOfAddonId(addonId)));
+    RootedValue targetValue(cx, ObjectValue(*target));
+    RootedValue thisValue(cx, args.thisv());
+    RootedObject argsArray(cx, ConvertArgsToArray(cx, args));
+    if (!argsArray)
+        return false;
+
+    RootedValue argsVal(cx, ObjectValue(*argsArray));
+    RootedValue returnVal(cx);
+
+    nsresult rv = interp->InterposeCall(addonIdValue, targetValue,
+                                        thisValue, argsVal, args.rval());
+    if (NS_FAILED(rv)) {
+        xpc::Throw(cx, rv);
+        return false;
+    }
+
+    return true;
+}
+
+template<typename Base>
+bool AddonWrapper<Base>::call(JSContext* cx, JS::Handle<JSObject*> wrapper,
+                              const JS::CallArgs& args) const
+{
+    bool done = false;
+    if (!InterposeCall(cx, wrapper, args, &done))
+        return false;
+
+    return done || Base::call(cx, wrapper, args);
+}
+
+template<typename Base>
+bool
+AddonWrapper<Base>::getPropertyDescriptor(JSContext* cx, HandleObject wrapper,
+                                          HandleId id, MutableHandle<PropertyDescriptor> desc) const
+{
+    if (!InterposeProperty(cx, wrapper, nullptr, id, desc))
+        return false;
+
+    if (desc.object())
+        return true;
+
+    return Base::getPropertyDescriptor(cx, wrapper, id, desc);
+}
+
+template<typename Base>
+bool
+AddonWrapper<Base>::getOwnPropertyDescriptor(JSContext* cx, HandleObject wrapper,
+                                             HandleId id, MutableHandle<PropertyDescriptor> desc) const
+{
+    if (!InterposeProperty(cx, wrapper, nullptr, id, desc))
+        return false;
+
+    if (desc.object())
+        return true;
+
+    return Base::getOwnPropertyDescriptor(cx, wrapper, id, desc);
+}
+
+template<typename Base>
+bool
+AddonWrapper<Base>::get(JSContext* cx, JS::Handle<JSObject*> wrapper, JS::Handle<Value> receiver,
+                        JS::Handle<jsid> id, JS::MutableHandle<JS::Value> vp) const
+{
+    PROFILER_LABEL_FUNC(js::ProfileEntry::Category::OTHER);
+
+    Rooted<PropertyDescriptor> desc(cx);
+    if (!InterposeProperty(cx, wrapper, nullptr, id, &desc))
+        return false;
+
+    if (!desc.object())
+        return Base::get(cx, wrapper, receiver, id, vp);
+
+    if (desc.getter()) {
+        return Call(cx, receiver, desc.getterObject(), HandleValueArray::empty(), vp);
+    } else {
+        vp.set(desc.value());
+        return true;
+    }
+}
+
+template<typename Base>
+bool
+AddonWrapper<Base>::set(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id, JS::HandleValue v,
+                        JS::HandleValue receiver, JS::ObjectOpResult& result) const
+{
+    Rooted<PropertyDescriptor> desc(cx);
+    if (!InterposeProperty(cx, wrapper, nullptr, id, &desc))
+        return false;
+
+    if (!desc.object())
+        return Base::set(cx, wrapper, id, v, receiver, result);
+
+    if (desc.setter()) {
+        MOZ_ASSERT(desc.hasSetterObject());
+        JS::AutoValueVector args(cx);
+        if (!args.append(v))
+            return false;
+        RootedValue fval(cx, ObjectValue(*desc.setterObject()));
+        RootedValue ignored(cx);
+        if (!JS::Call(cx, receiver, fval, args, &ignored))
+            return false;
+        return result.succeed();
+    }
+
+    return result.failCantSetInterposed();
+}
+
+template<typename Base>
+bool
+AddonWrapper<Base>::defineProperty(JSContext* cx, HandleObject wrapper, HandleId id,
+                                   Handle<PropertyDescriptor> desc,
+                                   ObjectOpResult& result) const
+{
+    Rooted<PropertyDescriptor> interpDesc(cx);
+    if (!InterposeProperty(cx, wrapper, nullptr, id, &interpDesc))
+        return false;
+
+    if (!interpDesc.object())
+        return Base::defineProperty(cx, wrapper, id, desc, result);
+
+    js::ReportASCIIErrorWithId(cx, "unable to modify interposed property %s", id);
+    return false;
+}
+
+template<typename Base>
+bool
+AddonWrapper<Base>::delete_(JSContext* cx, HandleObject wrapper, HandleId id,
+                            ObjectOpResult& result) const
+{
+    Rooted<PropertyDescriptor> desc(cx);
+    if (!InterposeProperty(cx, wrapper, nullptr, id, &desc))
+        return false;
+
+    if (!desc.object())
+        return Base::delete_(cx, wrapper, id, result);
+
+    js::ReportASCIIErrorWithId(cx, "unable to delete interposed property %s", id);
+    return false;
+}
+
+#define AddonWrapperCC AddonWrapper<CrossCompartmentWrapper>
+#define AddonWrapperXrayXPCWN AddonWrapper<PermissiveXrayXPCWN>
+#define AddonWrapperXrayDOM AddonWrapper<PermissiveXrayDOM>
+
+template<> const AddonWrapperCC AddonWrapperCC::singleton(0);
+template<> const AddonWrapperXrayXPCWN AddonWrapperXrayXPCWN::singleton(0);
+template<> const AddonWrapperXrayDOM AddonWrapperXrayDOM::singleton(0);
+
+template class AddonWrapperCC;
+template class AddonWrapperXrayXPCWN;
+template class AddonWrapperXrayDOM;
+
+#undef AddonWrapperCC
+#undef AddonWrapperXrayXPCWN
+#undef AddonWrapperXrayDOM
+
+} // namespace xpc