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 "xpcprivate.h"
8 #include "XPCWrapper.h"
9 #include "WrapperFactory.h"
10 #include "AccessCheck.h"
11 
12 #include "js/PropertyAndElement.h"  // JS_DefineFunction
13 
14 using namespace xpc;
15 using namespace mozilla;
16 using namespace JS;
17 
18 namespace XPCNativeWrapper {
19 
ThrowException(nsresult ex,JSContext * cx)20 static inline bool ThrowException(nsresult ex, JSContext* cx) {
21   XPCThrower::Throw(ex, cx);
22 
23   return false;
24 }
25 
UnwrapNW(JSContext * cx,unsigned argc,Value * vp)26 static bool UnwrapNW(JSContext* cx, unsigned argc, Value* vp) {
27   JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
28   if (args.length() != 1) {
29     return ThrowException(NS_ERROR_XPC_NOT_ENOUGH_ARGS, cx);
30   }
31 
32   JS::RootedValue v(cx, args[0]);
33   if (!v.isObject() || !js::IsCrossCompartmentWrapper(&v.toObject()) ||
34       !WrapperFactory::AllowWaiver(&v.toObject())) {
35     args.rval().set(v);
36     return true;
37   }
38 
39   bool ok = xpc::WrapperFactory::WaiveXrayAndWrap(cx, &v);
40   NS_ENSURE_TRUE(ok, false);
41   args.rval().set(v);
42   return true;
43 }
44 
XrayWrapperConstructor(JSContext * cx,unsigned argc,Value * vp)45 static bool XrayWrapperConstructor(JSContext* cx, unsigned argc, Value* vp) {
46   JS::CallArgs args = CallArgsFromVp(argc, vp);
47   if (args.length() == 0) {
48     return ThrowException(NS_ERROR_XPC_NOT_ENOUGH_ARGS, cx);
49   }
50 
51   if (!args[0].isObject()) {
52     if (args.isConstructing()) {
53       return ThrowException(NS_ERROR_XPC_BAD_CONVERT_JS, cx);
54     }
55 
56     args.rval().set(args[0]);
57     return true;
58   }
59 
60   args.rval().setObject(*js::UncheckedUnwrap(&args[0].toObject()));
61   return JS_WrapValue(cx, args.rval());
62 }
63 // static
AttachNewConstructorObject(JSContext * aCx,JS::HandleObject aGlobalObject)64 bool AttachNewConstructorObject(JSContext* aCx,
65                                 JS::HandleObject aGlobalObject) {
66   JSAutoRealm ar(aCx, aGlobalObject);
67   JSFunction* xpcnativewrapper = JS_DefineFunction(
68       aCx, aGlobalObject, "XPCNativeWrapper", XrayWrapperConstructor, 1,
69       JSPROP_READONLY | JSPROP_PERMANENT | JSFUN_CONSTRUCTOR);
70   if (!xpcnativewrapper) {
71     return false;
72   }
73   JS::RootedObject obj(aCx, JS_GetFunctionObject(xpcnativewrapper));
74   return JS_DefineFunction(aCx, obj, "unwrap", UnwrapNW, 1,
75                            JSPROP_READONLY | JSPROP_PERMANENT) != nullptr;
76 }
77 
78 }  // namespace XPCNativeWrapper
79 
80 namespace XPCWrapper {
81 
UnsafeUnwrapSecurityWrapper(JSObject * obj)82 JSObject* UnsafeUnwrapSecurityWrapper(JSObject* obj) {
83   if (js::IsProxy(obj)) {
84     return js::UncheckedUnwrap(obj);
85   }
86 
87   return obj;
88 }
89 
90 }  // namespace XPCWrapper
91