diff options
Diffstat (limited to 'js/xpconnect/src/XPCWrappedNativeJSOps.cpp')
| -rw-r--r-- | js/xpconnect/src/XPCWrappedNativeJSOps.cpp | 1236 |
1 files changed, 1236 insertions, 0 deletions
diff --git a/js/xpconnect/src/XPCWrappedNativeJSOps.cpp b/js/xpconnect/src/XPCWrappedNativeJSOps.cpp new file mode 100644 index 0000000000..6de0e959fd --- /dev/null +++ b/js/xpconnect/src/XPCWrappedNativeJSOps.cpp @@ -0,0 +1,1236 @@ +/* -*- 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/. */ + +/* JavaScript JSClasses and JSOps for our Wrapped Native JS Objects. */ + +#include "xpcprivate.h" +#include "xpc_make_class.h" +#include "mozilla/dom/BindingUtils.h" +#include "mozilla/Maybe.h" +#include "mozilla/Preferences.h" +#include "js/CharacterEncoding.h" +#include "js/Class.h" +#include "js/Object.h" // JS::GetClass +#include "js/Printf.h" +#include "js/PropertyAndElement.h" // JS_DefineProperty, JS_DefinePropertyById, JS_GetProperty, JS_GetPropertyById +#include "js/Symbol.h" + +#include <string_view> + +using namespace mozilla; +using namespace JS; +using namespace xpc; + +/***************************************************************************/ + +// All of the exceptions thrown into JS from this file go through here. +// That makes this a nice place to set a breakpoint. + +static bool Throw(nsresult errNum, JSContext* cx) { + XPCThrower::Throw(errNum, cx); + return false; +} + +// Handy macro used in many callback stub below. + +#define THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper) \ + PR_BEGIN_MACRO \ + if (!wrapper) return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); \ + if (!wrapper->IsValid()) return Throw(NS_ERROR_XPC_HAS_BEEN_SHUTDOWN, cx); \ + PR_END_MACRO + +/***************************************************************************/ + +static bool ToStringGuts(XPCCallContext& ccx) { + UniqueChars sz; + XPCWrappedNative* wrapper = ccx.GetWrapper(); + + if (wrapper) { + sz.reset(wrapper->ToString(ccx.GetTearOff())); + } else { + sz = JS_smprintf("[xpconnect wrapped native prototype]"); + } + + if (!sz) { + JS_ReportOutOfMemory(ccx); + return false; + } + + JSString* str = JS_NewStringCopyZ(ccx, sz.get()); + if (!str) { + return false; + } + + ccx.SetRetVal(JS::StringValue(str)); + return true; +} + +/***************************************************************************/ + +static bool XPC_WN_Shared_ToString(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + RootedObject obj(cx); + if (!args.computeThis(cx, &obj)) { + return false; + } + + XPCCallContext ccx(cx, obj); + if (!ccx.IsValid()) { + return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); + } + ccx.SetName(ccx.GetContext()->GetStringID(XPCJSContext::IDX_TO_STRING)); + ccx.SetArgsAndResultPtr(args.length(), args.array(), vp); + return ToStringGuts(ccx); +} + +static bool XPC_WN_Shared_ToSource(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + static constexpr std::string_view empty = "({})"; + JSString* str = JS_NewStringCopyN(cx, empty.data(), empty.length()); + if (!str) { + return false; + } + args.rval().setString(str); + + return true; +} + +static bool XPC_WN_Shared_toPrimitive(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + RootedObject obj(cx); + if (!JS_ValueToObject(cx, args.thisv(), &obj)) { + return false; + } + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + JSType hint; + if (!GetFirstArgumentAsTypeHint(cx, args, &hint)) { + return false; + } + + if (hint == JSTYPE_NUMBER) { + args.rval().set(NaNValue()); + return true; + } + + MOZ_ASSERT(hint == JSTYPE_STRING || hint == JSTYPE_UNDEFINED); + ccx.SetName(ccx.GetContext()->GetStringID(XPCJSContext::IDX_TO_STRING)); + ccx.SetArgsAndResultPtr(0, nullptr, args.rval().address()); + + XPCNativeMember* member = ccx.GetMember(); + if (member && member->IsMethod()) { + if (!XPCWrappedNative::CallMethod(ccx)) { + return false; + } + + if (args.rval().isPrimitive()) { + return true; + } + } + + // else... + return ToStringGuts(ccx); +} + +/***************************************************************************/ + +// A "double wrapped object" is a user JSObject that has been wrapped as a +// wrappedJS in order to be used by native code and then re-wrapped by a +// wrappedNative wrapper to be used by JS code. One might think of it as: +// wrappedNative(wrappedJS(underlying_JSObject)) +// This is done (as opposed to just unwrapping the wrapped JS and automatically +// returning the underlying JSObject) so that JS callers will see what looks +// Like any other xpcom object - and be limited to use its interfaces. +// + +/** + * When JavaScript code uses a component that is itself implemented in + * JavaScript then XPConnect will build a wrapper rather than directly + * expose the JSObject of the component. This allows components implemented + * in JavaScript to 'look' just like any other xpcom component (from the + * perspective of the JavaScript caller). This insulates the component from + * the caller and hides any properties or methods that are not part of the + * interface as declared in xpidl. Usually this is a good thing. + * + * However, in some cases it is useful to allow the JS caller access to the + * JS component's underlying implementation. In order to facilitate this + * XPConnect supports the 'wrappedJSObject' property. This 'wrappedJSObject' + * property is different than the XrayWrapper meaning. (The naming collision + * avoids having more than one magic XPConnect property name, but is + * confusing.) + * + * The caller code can do: + * + * // 'foo' is some xpcom component (that might be implemented in JS). + * var bar = foo.wrappedJSObject; + * if(bar) { + * // bar is the underlying JSObject. Do stuff with it here. + * } + * + * Recall that 'foo' above is an XPConnect wrapper, not the underlying JS + * object. The property get "foo.wrappedJSObject" will only succeed if three + * conditions are met: + * + * 1) 'foo' really is an XPConnect wrapper around a JSObject. + * 3) The caller must be system JS and not content. Double-wrapped XPCWJS should + * not be exposed to content except with a remote-XUL domain. + * + * Notes: + * + * a) If 'foo' above were the underlying JSObject and not a wrapper at all, + * then this all just works and XPConnect is not part of the picture at all. + * b) One might ask why 'foo' should not just implement an interface through + * which callers might get at the underlying object. There are two reasons: + * i) XPConnect would still have to do magic since JSObject is not a + * scriptable type. + * ii) Avoiding the explicit interface makes it easier for both the caller + * and the component. + */ + +static JSObject* GetDoubleWrappedJSObject(XPCCallContext& ccx, + XPCWrappedNative* wrapper) { + RootedObject obj(ccx); + { + nsCOMPtr<nsIXPConnectWrappedJS> underware = + do_QueryInterface(wrapper->GetIdentityObject()); + if (!underware) { + return nullptr; + } + RootedObject mainObj(ccx, underware->GetJSObject()); + if (mainObj) { + JSAutoRealm ar(ccx, underware->GetJSObjectGlobal()); + + // We don't have to root this ID, as it's already rooted by our context. + HandleId id = + ccx.GetContext()->GetStringID(XPCJSContext::IDX_WRAPPED_JSOBJECT); + + // If the `wrappedJSObject` property is defined, use the result of getting + // that property, otherwise fall back to the `mainObj` object which is + // directly being wrapped. + RootedValue val(ccx); + if (JS_GetPropertyById(ccx, mainObj, id, &val) && !val.isPrimitive()) { + obj = val.toObjectOrNull(); + } else { + obj = mainObj; + } + } + } + return obj; +} + +// This is the getter native function we use to handle 'wrappedJSObject' for +// double wrapped JSObjects. + +static bool XPC_WN_DoubleWrappedGetter(JSContext* cx, unsigned argc, + Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + if (!args.thisv().isObject()) { + JS_ReportErrorASCII( + cx, + "xpconnect double wrapped getter called on incompatible non-object"); + return false; + } + RootedObject obj(cx, &args.thisv().toObject()); + + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + MOZ_ASSERT(JS_TypeOfValue(cx, args.calleev()) == JSTYPE_FUNCTION, + "bad function"); + + RootedObject realObject(cx, GetDoubleWrappedJSObject(ccx, wrapper)); + if (!realObject) { + // This is pretty unexpected at this point. The object originally + // responded to this get property call and now gives no object. + // XXX Should this throw something at the caller? + args.rval().setNull(); + return true; + } + + // It is a double wrapped object. This should really never appear in + // content these days, but addons still do it - see bug 965921. + if (MOZ_UNLIKELY(!nsContentUtils::IsSystemCaller(cx))) { + JS_ReportErrorASCII(cx, + "Attempt to use .wrappedJSObject in untrusted code"); + return false; + } + args.rval().setObject(*realObject); + return JS_WrapValue(cx, args.rval()); +} + +/***************************************************************************/ + +// This is our shared function to define properties on our JSObjects. + +/* + * NOTE: + * We *never* set the tearoff names (e.g. nsIFoo) as JS_ENUMERATE. + * We *never* set toString or toSource as JS_ENUMERATE. + */ + +static bool DefinePropertyIfFound( + XPCCallContext& ccx, HandleObject obj, HandleId idArg, XPCNativeSet* set, + XPCNativeInterface* ifaceArg, XPCNativeMember* member, + XPCWrappedNativeScope* scope, bool reflectToStringAndToSource, + XPCWrappedNative* wrapperToReflectInterfaceNames, + XPCWrappedNative* wrapperToReflectDoubleWrap, nsIXPCScriptable* scr, + unsigned propFlags, bool* resolved) { + RootedId id(ccx, idArg); + RefPtr<XPCNativeInterface> iface = ifaceArg; + XPCJSContext* xpccx = ccx.GetContext(); + bool found; + const char* name; + + propFlags |= JSPROP_RESOLVING; + + if (set) { + if (iface) { + found = true; + } else { + found = set->FindMember(id, &member, &iface); + } + } else + found = (nullptr != (member = iface->FindMember(id))); + + if (!found) { + if (reflectToStringAndToSource) { + JSNative call; + if (id == xpccx->GetStringID(XPCJSContext::IDX_TO_STRING)) { + call = XPC_WN_Shared_ToString; + name = xpccx->GetStringName(XPCJSContext::IDX_TO_STRING); + } else if (id == xpccx->GetStringID(XPCJSContext::IDX_TO_SOURCE)) { + call = XPC_WN_Shared_ToSource; + name = xpccx->GetStringName(XPCJSContext::IDX_TO_SOURCE); + } else if (id.isWellKnownSymbol(JS::SymbolCode::toPrimitive)) { + call = XPC_WN_Shared_toPrimitive; + name = "[Symbol.toPrimitive]"; + } else { + call = nullptr; + } + + if (call) { + RootedFunction fun(ccx, JS_NewFunction(ccx, call, 0, 0, name)); + if (!fun) { + JS_ReportOutOfMemory(ccx); + return false; + } + + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + RootedObject value(ccx, JS_GetFunctionObject(fun)); + return JS_DefinePropertyById(ccx, obj, id, value, + propFlags & ~JSPROP_ENUMERATE); + } + } + // This *might* be a tearoff name that is not yet part of our + // set. Let's lookup the name and see if it is the name of an + // interface. Then we'll see if the object actually *does* this + // interface and add a tearoff as necessary. + + if (wrapperToReflectInterfaceNames) { + JS::UniqueChars name; + RefPtr<XPCNativeInterface> iface2; + XPCWrappedNativeTearOff* to; + RootedObject jso(ccx); + nsresult rv = NS_OK; + + bool defineProperty = false; + do { + if (!id.isString()) { + break; + } + + name = JS_EncodeStringToLatin1(ccx, id.toString()); + if (!name) { + break; + } + + iface2 = XPCNativeInterface::GetNewOrUsed(ccx, name.get()); + if (!iface2) { + break; + } + + to = + wrapperToReflectInterfaceNames->FindTearOff(ccx, iface2, true, &rv); + if (!to) { + break; + } + + jso = to->GetJSObject(); + if (!jso) { + break; + } + + defineProperty = true; + } while (false); + + if (defineProperty) { + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + return JS_DefinePropertyById(ccx, obj, id, jso, + propFlags & ~JSPROP_ENUMERATE); + } else if (NS_FAILED(rv) && rv != NS_ERROR_NO_INTERFACE) { + return Throw(rv, ccx); + } + } + + // This *might* be a double wrapped JSObject + if (wrapperToReflectDoubleWrap && + id == xpccx->GetStringID(XPCJSContext::IDX_WRAPPED_JSOBJECT) && + GetDoubleWrappedJSObject(ccx, wrapperToReflectDoubleWrap)) { + // We build and add a getter function. + // A security check is done on a per-get basis. + + JSFunction* fun; + + id = xpccx->GetStringID(XPCJSContext::IDX_WRAPPED_JSOBJECT); + name = xpccx->GetStringName(XPCJSContext::IDX_WRAPPED_JSOBJECT); + + fun = JS_NewFunction(ccx, XPC_WN_DoubleWrappedGetter, 0, 0, name); + + if (!fun) { + return false; + } + + RootedObject funobj(ccx, JS_GetFunctionObject(fun)); + if (!funobj) { + return false; + } + + propFlags &= ~JSPROP_ENUMERATE; + + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + return JS_DefinePropertyById(ccx, obj, id, funobj, nullptr, propFlags); + } + + if (resolved) { + *resolved = false; + } + return true; + } + + if (!member) { + if (wrapperToReflectInterfaceNames) { + XPCWrappedNativeTearOff* to = + wrapperToReflectInterfaceNames->FindTearOff(ccx, iface, true); + + if (!to) { + return false; + } + RootedObject jso(ccx, to->GetJSObject()); + if (!jso) { + return false; + } + + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + return JS_DefinePropertyById(ccx, obj, id, jso, + propFlags & ~JSPROP_ENUMERATE); + } + if (resolved) { + *resolved = false; + } + return true; + } + + if (member->IsConstant()) { + RootedValue val(ccx); + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + return member->GetConstantValue(ccx, iface, val.address()) && + JS_DefinePropertyById(ccx, obj, id, val, propFlags); + } + + if (id == xpccx->GetStringID(XPCJSContext::IDX_TO_STRING) || + id == xpccx->GetStringID(XPCJSContext::IDX_TO_SOURCE) || + (scr && scr->DontEnumQueryInterface() && + id == xpccx->GetStringID(XPCJSContext::IDX_QUERY_INTERFACE))) + propFlags &= ~JSPROP_ENUMERATE; + + RootedValue funval(ccx); + if (!member->NewFunctionObject(ccx, iface, obj, funval.address())) { + return false; + } + + if (member->IsMethod()) { + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + return JS_DefinePropertyById(ccx, obj, id, funval, propFlags); + } + + // else... + + MOZ_ASSERT(member->IsAttribute(), "way broken!"); + + propFlags &= ~JSPROP_READONLY; + RootedObject funobjGetter(ccx, funval.toObjectOrNull()); + RootedObject funobjSetter(ccx); + if (member->IsWritableAttribute()) { + funobjSetter = funobjGetter; + } + + AutoResolveName arn(ccx, id); + if (resolved) { + *resolved = true; + } + + return JS_DefinePropertyById(ccx, obj, id, funobjGetter, funobjSetter, + propFlags); +} + +/***************************************************************************/ +/***************************************************************************/ + +static bool XPC_WN_OnlyIWrite_AddPropertyStub(JSContext* cx, HandleObject obj, + HandleId id, HandleValue v) { + XPCCallContext ccx(cx, obj, nullptr, id); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + // Allow only XPConnect to add/set the property + if (ccx.GetResolveName() == id) { + return true; + } + + return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx); +} + +bool XPC_WN_CannotModifyPropertyStub(JSContext* cx, HandleObject obj, + HandleId id, HandleValue v) { + return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx); +} + +bool XPC_WN_CannotDeletePropertyStub(JSContext* cx, HandleObject obj, + HandleId id, ObjectOpResult& result) { + return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx); +} + +bool XPC_WN_Shared_Enumerate(JSContext* cx, HandleObject obj) { + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + // Since we aren't going to enumerate tearoff names and the prototype + // handles non-mutated members, we can do this potential short-circuit. + if (!wrapper->HasMutatedSet()) { + return true; + } + + XPCNativeSet* set = wrapper->GetSet(); + XPCNativeSet* protoSet = + wrapper->HasProto() ? wrapper->GetProto()->GetSet() : nullptr; + + uint16_t interface_count = set->GetInterfaceCount(); + XPCNativeInterface** interfaceArray = set->GetInterfaceArray(); + for (uint16_t i = 0; i < interface_count; i++) { + XPCNativeInterface* iface = interfaceArray[i]; + uint16_t member_count = iface->GetMemberCount(); + for (uint16_t k = 0; k < member_count; k++) { + XPCNativeMember* member = iface->GetMemberAt(k); + jsid name = member->GetName(); + + // Skip if this member is going to come from the proto. + uint16_t index; + if (protoSet && protoSet->FindMember(name, nullptr, &index) && index == i) + continue; + + JS_MarkCrossZoneId(cx, name); + if (!xpc_ForcePropertyResolve(cx, obj, name)) { + return false; + } + } + } + return true; +} + +/***************************************************************************/ + +enum WNHelperType { WN_NOHELPER, WN_HELPER }; + +static void WrappedNativeFinalize(JS::GCContext* gcx, JSObject* obj, + WNHelperType helperType) { + const JSClass* clazz = JS::GetClass(obj); + if (clazz->flags & JSCLASS_DOM_GLOBAL) { + mozilla::dom::DestroyProtoAndIfaceCache(obj); + } + XPCWrappedNative* wrapper = JS::GetObjectISupports<XPCWrappedNative>(obj); + if (!wrapper) { + return; + } + + if (helperType == WN_HELPER) { + wrapper->GetScriptable()->Finalize(wrapper, gcx, obj); + } + wrapper->FlatJSObjectFinalized(); +} + +static size_t WrappedNativeObjectMoved(JSObject* obj, JSObject* old) { + XPCWrappedNative* wrapper = JS::GetObjectISupports<XPCWrappedNative>(obj); + if (!wrapper) { + return 0; + } + + wrapper->FlatJSObjectMoved(obj, old); + return 0; +} + +void XPC_WN_NoHelper_Finalize(JS::GCContext* gcx, JSObject* obj) { + WrappedNativeFinalize(gcx, obj, WN_NOHELPER); +} + +/* + * General comment about XPConnect tracing: Given a C++ object |wrapper| and its + * corresponding JS object |obj|, calling |wrapper->TraceSelf| will ask the JS + * engine to mark |obj|. Eventually, this will lead to the trace hook being + * called for |obj|. The trace hook should call |wrapper->TraceInside|, which + * should mark any JS objects held by |wrapper| as members. + */ + +/* static */ +void XPCWrappedNative::Trace(JSTracer* trc, JSObject* obj) { + const JSClass* clazz = JS::GetClass(obj); + if (clazz->flags & JSCLASS_DOM_GLOBAL) { + mozilla::dom::TraceProtoAndIfaceCache(trc, obj); + } + MOZ_ASSERT(clazz->isWrappedNative()); + + XPCWrappedNative* wrapper = XPCWrappedNative::Get(obj); + if (wrapper && wrapper->IsValid()) { + wrapper->TraceInside(trc); + } +} + +void XPCWrappedNative_Trace(JSTracer* trc, JSObject* obj) { + XPCWrappedNative::Trace(trc, obj); +} + +static bool XPC_WN_NoHelper_Resolve(JSContext* cx, HandleObject obj, + HandleId id, bool* resolvedp) { + XPCCallContext ccx(cx, obj, nullptr, id); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + XPCNativeSet* set = ccx.GetSet(); + if (!set) { + return true; + } + + // Don't resolve properties that are on our prototype. + if (ccx.GetInterface() && !ccx.GetStaticMemberIsLocal()) { + return true; + } + + return DefinePropertyIfFound( + ccx, obj, id, set, nullptr, nullptr, wrapper->GetScope(), true, wrapper, + wrapper, nullptr, JSPROP_ENUMERATE | JSPROP_READONLY | JSPROP_PERMANENT, + resolvedp); +} + +static const JSClassOps XPC_WN_NoHelper_JSClassOps = { + XPC_WN_OnlyIWrite_AddPropertyStub, // addProperty + XPC_WN_CannotDeletePropertyStub, // delProperty + XPC_WN_Shared_Enumerate, // enumerate + nullptr, // newEnumerate + XPC_WN_NoHelper_Resolve, // resolve + nullptr, // mayResolve + XPC_WN_NoHelper_Finalize, // finalize + nullptr, // call + nullptr, // construct + XPCWrappedNative::Trace, // trace +}; + +const js::ClassExtension XPC_WN_JSClassExtension = { + WrappedNativeObjectMoved, // objectMovedOp +}; + +const JSClass XPC_WN_NoHelper_JSClass = { + "XPCWrappedNative_NoHelper", + JSCLASS_IS_WRAPPED_NATIVE | JSCLASS_HAS_RESERVED_SLOTS(1) | + JSCLASS_SLOT0_IS_NSISUPPORTS | JSCLASS_FOREGROUND_FINALIZE, + &XPC_WN_NoHelper_JSClassOps, + JS_NULL_CLASS_SPEC, + &XPC_WN_JSClassExtension, + JS_NULL_OBJECT_OPS}; + +/***************************************************************************/ + +bool XPC_WN_MaybeResolvingPropertyStub(JSContext* cx, HandleObject obj, + HandleId id, HandleValue v) { + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + if (ccx.GetResolvingWrapper() == wrapper) { + return true; + } + return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx); +} + +bool XPC_WN_MaybeResolvingDeletePropertyStub(JSContext* cx, HandleObject obj, + HandleId id, + ObjectOpResult& result) { + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + if (ccx.GetResolvingWrapper() == wrapper) { + return result.succeed(); + } + return Throw(NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN, cx); +} + +// macro fun! +#define PRE_HELPER_STUB \ + /* It's very important for "unwrapped" to be rooted here. */ \ + RootedObject unwrapped(cx, js::CheckedUnwrapDynamic(obj, cx, false)); \ + if (!unwrapped) { \ + JS_ReportErrorASCII(cx, "Permission denied to operate on object."); \ + return false; \ + } \ + if (!IsWrappedNativeReflector(unwrapped)) { \ + return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); \ + } \ + XPCWrappedNative* wrapper = XPCWrappedNative::Get(unwrapped); \ + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); \ + bool retval = true; \ + nsresult rv = wrapper->GetScriptable()-> + +#define POST_HELPER_STUB \ + if (NS_FAILED(rv)) return Throw(rv, cx); \ + return retval; + +bool XPC_WN_Helper_Call(JSContext* cx, unsigned argc, Value* vp) { + JS::CallArgs args = JS::CallArgsFromVp(argc, vp); + // N.B. we want obj to be the callee, not JS_THIS(cx, vp) + RootedObject obj(cx, &args.callee()); + + XPCCallContext ccx(cx, obj, nullptr, JS::VoidHandlePropertyKey, args.length(), + args.array(), args.rval().address()); + if (!ccx.IsValid()) { + return false; + } + + PRE_HELPER_STUB + Call(wrapper, cx, obj, args, &retval); + POST_HELPER_STUB +} + +bool XPC_WN_Helper_Construct(JSContext* cx, unsigned argc, Value* vp) { + JS::CallArgs args = JS::CallArgsFromVp(argc, vp); + RootedObject obj(cx, &args.callee()); + if (!obj) { + return false; + } + + XPCCallContext ccx(cx, obj, nullptr, JS::VoidHandlePropertyKey, args.length(), + args.array(), args.rval().address()); + if (!ccx.IsValid()) { + return false; + } + + PRE_HELPER_STUB + Construct(wrapper, cx, obj, args, &retval); + POST_HELPER_STUB +} + +static bool XPC_WN_Helper_HasInstance(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + if (!args.requireAtLeast(cx, "WrappedNative[Symbol.hasInstance]", 1)) { + return false; + } + + if (!args.thisv().isObject()) { + JS_ReportErrorASCII( + cx, "WrappedNative[Symbol.hasInstance]: unexpected this value"); + return false; + } + + RootedObject obj(cx, &args.thisv().toObject()); + RootedValue val(cx, args.get(0)); + + bool retval2; + PRE_HELPER_STUB + HasInstance(wrapper, cx, obj, val, &retval2, &retval); + args.rval().setBoolean(retval2); + POST_HELPER_STUB +} + +void XPC_WN_Helper_Finalize(JS::GCContext* gcx, JSObject* obj) { + WrappedNativeFinalize(gcx, obj, WN_HELPER); +} + +// RAII class used to store the wrapper in the context when resolving a lazy +// property on its JS reflector. This is used by XPC_WN_MaybeResolving to allow +// adding properties while resolving. +class MOZ_RAII AutoSetResolvingWrapper { + public: + AutoSetResolvingWrapper(XPCCallContext& ccx, XPCWrappedNative* wrapper) + : mCcx(ccx), mOldResolvingWrapper(ccx.SetResolvingWrapper(wrapper)) {} + + ~AutoSetResolvingWrapper() { + (void)mCcx.SetResolvingWrapper(mOldResolvingWrapper); + } + + private: + XPCCallContext& mCcx; + XPCWrappedNative* mOldResolvingWrapper; +}; + +bool XPC_WN_Helper_Resolve(JSContext* cx, HandleObject obj, HandleId id, + bool* resolvedp) { + nsresult rv = NS_OK; + bool retval = true; + bool resolved = false; + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + RootedId old(cx, ccx.SetResolveName(id)); + + nsCOMPtr<nsIXPCScriptable> scr = wrapper->GetScriptable(); + + // Resolve a Symbol.hasInstance property if we want custom `instanceof` + // behavior. + if (scr && scr->WantHasInstance() && + id.isWellKnownSymbol(SymbolCode::hasInstance)) { + mozilla::Maybe<AutoSetResolvingWrapper> asrw; + if (scr->AllowPropModsDuringResolve()) { + asrw.emplace(ccx, wrapper); + } + if (!JS_DefineFunctionById( + cx, obj, id, XPC_WN_Helper_HasInstance, 1, + JSPROP_READONLY | JSPROP_PERMANENT | JSPROP_RESOLVING)) { + rv = NS_ERROR_FAILURE; + } else { + resolved = true; + } + } + + if (scr && scr->WantResolve()) { + mozilla::Maybe<AutoSetResolvingWrapper> asrw; + if (scr->AllowPropModsDuringResolve()) { + asrw.emplace(ccx, wrapper); + } + rv = scr->Resolve(wrapper, cx, obj, id, &resolved, &retval); + } + + old = ccx.SetResolveName(old); + MOZ_ASSERT(old == id, "bad nest"); + + if (NS_FAILED(rv)) { + return Throw(rv, cx); + } + + if (resolved) { + *resolvedp = true; + } else if (wrapper->HasMutatedSet()) { + // We are here if scriptable did not resolve this property and + // it *might* be in the instance set but not the proto set. + + XPCNativeSet* set = wrapper->GetSet(); + XPCNativeSet* protoSet = + wrapper->HasProto() ? wrapper->GetProto()->GetSet() : nullptr; + XPCNativeMember* member = nullptr; + RefPtr<XPCNativeInterface> iface; + bool IsLocal = false; + + if (set->FindMember(id, &member, &iface, protoSet, &IsLocal) && IsLocal) { + XPCWrappedNative* wrapperForInterfaceNames = + (scr && scr->DontReflectInterfaceNames()) ? nullptr : wrapper; + + AutoSetResolvingWrapper asrw(ccx, wrapper); + retval = DefinePropertyIfFound( + ccx, obj, id, set, iface, member, wrapper->GetScope(), false, + wrapperForInterfaceNames, nullptr, scr, JSPROP_ENUMERATE, resolvedp); + } + } + + return retval; +} + +/***************************************************************************/ + +bool XPC_WN_NewEnumerate(JSContext* cx, HandleObject obj, + MutableHandleIdVector properties, + bool enumerableOnly) { + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + nsCOMPtr<nsIXPCScriptable> scr = wrapper->GetScriptable(); + if (!scr || !scr->WantNewEnumerate()) { + return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); + } + + if (!XPC_WN_Shared_Enumerate(cx, obj)) { + return false; + } + + bool retval = true; + nsresult rv = + scr->NewEnumerate(wrapper, cx, obj, properties, enumerableOnly, &retval); + if (NS_FAILED(rv)) { + return Throw(rv, cx); + } + return retval; +} + +/***************************************************************************/ +/***************************************************************************/ + +// Compatibility hack. +// +// XPConnect used to do all sorts of funny tricks to find the "correct" +// |this| object for a given method (often to the detriment of proper +// call/apply). When these tricks were removed, a fair amount of chrome +// code broke, because it was relying on being able to grab methods off +// some XPCOM object (like the nsITelemetry service) and invoke them without +// a proper |this|. So, if it's quite clear that we're in this situation and +// about to use a |this| argument that just won't work, fix things up. +// +// This hack is only useful for getters/setters if someone sets an XPCOM object +// as the prototype for a vanilla JS object and expects the XPCOM attributes to +// work on the derived object, which we really don't want to support. But we +// handle it anyway, for now, to minimize regression risk on an already-risky +// landing. +// +// This hack is mainly useful for the NoHelper JSClass. We also fix up +// Components.utils because it implements nsIXPCScriptable (giving it a custom +// JSClass) but not nsIClassInfo (which would put the methods on a prototype). + +#define IS_NOHELPER_CLASS(clasp) (clasp == &XPC_WN_NoHelper_JSClass) +#define IS_CU_CLASS(clasp) \ + (clasp->name[0] == 'n' && !strcmp(clasp->name, "nsXPCComponents_Utils")) + +MOZ_ALWAYS_INLINE JSObject* FixUpThisIfBroken(JSObject* obj, JSObject* funobj) { + if (funobj) { + JSObject* parentObj = + &js::GetFunctionNativeReserved(funobj, XPC_FUNCTION_PARENT_OBJECT_SLOT) + .toObject(); + const JSClass* parentClass = JS::GetClass(parentObj); + if (MOZ_UNLIKELY( + (IS_NOHELPER_CLASS(parentClass) || IS_CU_CLASS(parentClass)) && + (JS::GetClass(obj) != parentClass))) { + return parentObj; + } + } + return obj; +} + +bool XPC_WN_CallMethod(JSContext* cx, unsigned argc, Value* vp) { + JS::CallArgs args = JS::CallArgsFromVp(argc, vp); + MOZ_ASSERT(JS_TypeOfValue(cx, args.calleev()) == JSTYPE_FUNCTION, + "bad function"); + RootedObject funobj(cx, &args.callee()); + + RootedObject obj(cx); + if (!args.computeThis(cx, &obj)) { + return false; + } + + obj = FixUpThisIfBroken(obj, funobj); + XPCCallContext ccx(cx, obj, funobj, JS::VoidHandlePropertyKey, args.length(), + args.array(), vp); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + RefPtr<XPCNativeInterface> iface; + XPCNativeMember* member; + + if (!XPCNativeMember::GetCallInfo(funobj, &iface, &member)) { + return Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, cx); + } + ccx.SetCallInfo(iface, member, false); + return XPCWrappedNative::CallMethod(ccx); +} + +bool XPC_WN_GetterSetter(JSContext* cx, unsigned argc, Value* vp) { + JS::CallArgs args = JS::CallArgsFromVp(argc, vp); + MOZ_ASSERT(JS_TypeOfValue(cx, args.calleev()) == JSTYPE_FUNCTION, + "bad function"); + RootedObject funobj(cx, &args.callee()); + + if (!args.thisv().isObject()) { + JS_ReportErrorASCII( + cx, "xpconnect getter/setter called on incompatible non-object"); + return false; + } + RootedObject obj(cx, &args.thisv().toObject()); + + obj = FixUpThisIfBroken(obj, funobj); + XPCCallContext ccx(cx, obj, funobj, JS::VoidHandlePropertyKey, args.length(), + args.array(), vp); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + RefPtr<XPCNativeInterface> iface; + XPCNativeMember* member; + + if (!XPCNativeMember::GetCallInfo(funobj, &iface, &member)) { + return Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, cx); + } + + if (args.length() != 0 && member->IsWritableAttribute()) { + ccx.SetCallInfo(iface, member, true); + bool retval = XPCWrappedNative::SetAttribute(ccx); + if (retval) { + args.rval().set(args[0]); + } + return retval; + } + // else... + + ccx.SetCallInfo(iface, member, false); + return XPCWrappedNative::GetAttribute(ccx); +} + +/***************************************************************************/ + +/* static */ +XPCWrappedNativeProto* XPCWrappedNativeProto::Get(JSObject* obj) { + MOZ_ASSERT(JS::GetClass(obj) == &XPC_WN_Proto_JSClass); + return JS::GetMaybePtrFromReservedSlot<XPCWrappedNativeProto>(obj, ProtoSlot); +} + +/* static */ +XPCWrappedNativeTearOff* XPCWrappedNativeTearOff::Get(JSObject* obj) { + MOZ_ASSERT(JS::GetClass(obj) == &XPC_WN_Tearoff_JSClass); + return JS::GetMaybePtrFromReservedSlot<XPCWrappedNativeTearOff>(obj, + TearOffSlot); +} + +static bool XPC_WN_Proto_Enumerate(JSContext* cx, HandleObject obj) { + MOZ_ASSERT(JS::GetClass(obj) == &XPC_WN_Proto_JSClass, "bad proto"); + XPCWrappedNativeProto* self = XPCWrappedNativeProto::Get(obj); + if (!self) { + return false; + } + + XPCNativeSet* set = self->GetSet(); + if (!set) { + return false; + } + + XPCCallContext ccx(cx); + if (!ccx.IsValid()) { + return false; + } + + uint16_t interface_count = set->GetInterfaceCount(); + XPCNativeInterface** interfaceArray = set->GetInterfaceArray(); + for (uint16_t i = 0; i < interface_count; i++) { + XPCNativeInterface* iface = interfaceArray[i]; + uint16_t member_count = iface->GetMemberCount(); + + for (uint16_t k = 0; k < member_count; k++) { + jsid name = iface->GetMemberAt(k)->GetName(); + JS_MarkCrossZoneId(cx, name); + if (!xpc_ForcePropertyResolve(cx, obj, name)) { + return false; + } + } + } + + return true; +} + +static void XPC_WN_Proto_Finalize(JS::GCContext* gcx, JSObject* obj) { + // This can be null if xpc shutdown has already happened + XPCWrappedNativeProto* p = XPCWrappedNativeProto::Get(obj); + if (p) { + p->JSProtoObjectFinalized(gcx, obj); + } +} + +static size_t XPC_WN_Proto_ObjectMoved(JSObject* obj, JSObject* old) { + // This can be null if xpc shutdown has already happened + XPCWrappedNativeProto* p = XPCWrappedNativeProto::Get(obj); + if (!p) { + return 0; + } + + p->JSProtoObjectMoved(obj, old); + return 0; +} + +/*****************************************************/ + +static bool XPC_WN_OnlyIWrite_Proto_AddPropertyStub(JSContext* cx, + HandleObject obj, + HandleId id, + HandleValue v) { + MOZ_ASSERT(JS::GetClass(obj) == &XPC_WN_Proto_JSClass, "bad proto"); + + XPCWrappedNativeProto* self = XPCWrappedNativeProto::Get(obj); + if (!self) { + return false; + } + + XPCCallContext ccx(cx); + if (!ccx.IsValid()) { + return false; + } + + // Allow XPConnect to add the property only + if (ccx.GetResolveName() == id) { + return true; + } + + return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); +} + +static bool XPC_WN_Proto_Resolve(JSContext* cx, HandleObject obj, HandleId id, + bool* resolvedp) { + MOZ_ASSERT(JS::GetClass(obj) == &XPC_WN_Proto_JSClass, "bad proto"); + + XPCWrappedNativeProto* self = XPCWrappedNativeProto::Get(obj); + if (!self) { + return false; + } + + XPCCallContext ccx(cx); + if (!ccx.IsValid()) { + return false; + } + + nsCOMPtr<nsIXPCScriptable> scr = self->GetScriptable(); + + return DefinePropertyIfFound( + ccx, obj, id, self->GetSet(), nullptr, nullptr, self->GetScope(), true, + nullptr, nullptr, scr, + JSPROP_READONLY | JSPROP_PERMANENT | JSPROP_ENUMERATE, resolvedp); +} + +static const JSClassOps XPC_WN_Proto_JSClassOps = { + XPC_WN_OnlyIWrite_Proto_AddPropertyStub, // addProperty + XPC_WN_CannotDeletePropertyStub, // delProperty + XPC_WN_Proto_Enumerate, // enumerate + nullptr, // newEnumerate + XPC_WN_Proto_Resolve, // resolve + nullptr, // mayResolve + XPC_WN_Proto_Finalize, // finalize + nullptr, // call + nullptr, // construct + nullptr, // trace +}; + +static const js::ClassExtension XPC_WN_Proto_ClassExtension = { + XPC_WN_Proto_ObjectMoved, // objectMovedOp +}; + +const JSClass XPC_WN_Proto_JSClass = { + "XPC_WN_Proto_JSClass", + JSCLASS_HAS_RESERVED_SLOTS(XPCWrappedNativeProto::SlotCount) | + JSCLASS_FOREGROUND_FINALIZE, + &XPC_WN_Proto_JSClassOps, + JS_NULL_CLASS_SPEC, + &XPC_WN_Proto_ClassExtension, + JS_NULL_OBJECT_OPS}; + +/***************************************************************************/ + +static bool XPC_WN_TearOff_Enumerate(JSContext* cx, HandleObject obj) { + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + XPCWrappedNativeTearOff* to = ccx.GetTearOff(); + XPCNativeInterface* iface; + + if (!to || nullptr == (iface = to->GetInterface())) { + return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); + } + + uint16_t member_count = iface->GetMemberCount(); + for (uint16_t k = 0; k < member_count; k++) { + jsid name = iface->GetMemberAt(k)->GetName(); + JS_MarkCrossZoneId(cx, name); + if (!xpc_ForcePropertyResolve(cx, obj, name)) { + return false; + } + } + + return true; +} + +static bool XPC_WN_TearOff_Resolve(JSContext* cx, HandleObject obj, HandleId id, + bool* resolvedp) { + XPCCallContext ccx(cx, obj); + XPCWrappedNative* wrapper = ccx.GetWrapper(); + THROW_AND_RETURN_IF_BAD_WRAPPER(cx, wrapper); + + XPCWrappedNativeTearOff* to = ccx.GetTearOff(); + XPCNativeInterface* iface; + + if (!to || nullptr == (iface = to->GetInterface())) { + return Throw(NS_ERROR_XPC_BAD_OP_ON_WN_PROTO, cx); + } + + return DefinePropertyIfFound( + ccx, obj, id, nullptr, iface, nullptr, wrapper->GetScope(), true, nullptr, + nullptr, nullptr, JSPROP_READONLY | JSPROP_PERMANENT | JSPROP_ENUMERATE, + resolvedp); +} + +static void XPC_WN_TearOff_Finalize(JS::GCContext* gcx, JSObject* obj) { + XPCWrappedNativeTearOff* p = XPCWrappedNativeTearOff::Get(obj); + if (!p) { + return; + } + p->JSObjectFinalized(); +} + +static size_t XPC_WN_TearOff_ObjectMoved(JSObject* obj, JSObject* old) { + XPCWrappedNativeTearOff* p = XPCWrappedNativeTearOff::Get(obj); + if (!p) { + return 0; + } + p->JSObjectMoved(obj, old); + return 0; +} + +static const JSClassOps XPC_WN_Tearoff_JSClassOps = { + XPC_WN_OnlyIWrite_AddPropertyStub, // addProperty + XPC_WN_CannotDeletePropertyStub, // delProperty + XPC_WN_TearOff_Enumerate, // enumerate + nullptr, // newEnumerate + XPC_WN_TearOff_Resolve, // resolve + nullptr, // mayResolve + XPC_WN_TearOff_Finalize, // finalize + nullptr, // call + nullptr, // construct + nullptr, // trace +}; + +static const js::ClassExtension XPC_WN_Tearoff_JSClassExtension = { + XPC_WN_TearOff_ObjectMoved, // objectMovedOp +}; + +const JSClass XPC_WN_Tearoff_JSClass = { + "WrappedNative_TearOff", + JSCLASS_HAS_RESERVED_SLOTS(XPCWrappedNativeTearOff::SlotCount) | + JSCLASS_FOREGROUND_FINALIZE, + &XPC_WN_Tearoff_JSClassOps, JS_NULL_CLASS_SPEC, + &XPC_WN_Tearoff_JSClassExtension}; |