protected:

enum Kind {

kSandbox,

kContext,

kProxyGlobal

};

Environment* const env_;

Persistent<Object> sandbox_;

Persistent<Context> context_;

Persistent<Object> proxy_global_;

int references_;

public:

explicit ContextifyContext(Environment* env, Local<Object> sandbox)

: env_(env),

sandbox_(env->isolate(), sandbox),

// Wait for sandbox_, proxy_global_, and context_ to die

references_(0) {

context_.Reset(env->isolate(), CreateV8Context(env));

sandbox_.SetWeak(this, WeakCallback<Object, kSandbox>);

sandbox_.MarkIndependent();

references_++;

// Allocation failure or maximum call stack size reached

if (context_.IsEmpty())

return;

context_.SetWeak(this, WeakCallback<Context, kContext>);

context_.MarkIndependent();

references_++;

proxy_global_.Reset(env->isolate(), context()->Global());

proxy_global_.SetWeak(this, WeakCallback<Object, kProxyGlobal>);

proxy_global_.MarkIndependent();

references_++;

}

~ContextifyContext() {

context_.Reset();

proxy_global_.Reset();

sandbox_.Reset();

}

inline Environment* env() const {

return env_;

}

inline Local<Context> context() const {

return PersistentToLocal(env()->isolate(), context_);

}

// XXX(isaacs): This function only exists because of a shortcoming of

// the V8 SetNamedPropertyHandler function.

//

// It does not provide a way to intercept Object.defineProperty(..)

// calls. As a result, these properties are not copied onto the

// contextified sandbox when a new global property is added via either

// a function declaration or a Object.defineProperty(global, ...) call.

//

// Note that any function declarations or Object.defineProperty()

// globals that are created asynchronously (in a setTimeout, callback,

// etc.) will happen AFTER the call to copy properties, and thus not be

// caught.

//

// The way to properly fix this is to add some sort of a

// Object::SetNamedDefinePropertyHandler() function that takes a callback,

// which receives the property name and property descriptor as arguments.

//

// Luckily, such situations are rare, and asynchronously-added globals

// weren't supported by Node's VM module until 0.12 anyway. But, this

// should be fixed properly in V8, and this copy function should be

// removed once there is a better way.

void CopyProperties() {

HandleScope scope(env()->isolate());

Local<Context> context = PersistentToLocal(env()->isolate(), context_);

Local<Object> global =

context->Global()->GetPrototype()->ToObject(env()->isolate());

Local<Object> sandbox = PersistentToLocal(env()->isolate(), sandbox_);

Local<Function> clone_property_method;

Local<Array> names = global->GetOwnPropertyNames();

int length = names->Length();

for (int i = 0; i < length; i++) {

Local<String> key = names->Get(i)->ToString(env()->isolate());

bool has = sandbox->HasOwnProperty(key);

if (!has) {

// Could also do this like so:

//

// PropertyAttribute att = global->GetPropertyAttributes(key_v);

// Local<Value> val = global->Get(key_v);

// sandbox->ForceSet(key_v, val, att);

//

// However, this doesn't handle ES6-style properties configured with

// Object.defineProperty, and that's exactly what we're up against at

// this point. ForceSet(key,val,att) only supports value properties

// with the ES3-style attribute flags (DontDelete/DontEnum/ReadOnly),

// which doesn't faithfully capture the full range of configurations

// that can be done using Object.defineProperty.

if (clone_property_method.IsEmpty()) {

Local<String> code = FIXED_ONE_BYTE_STRING(env()->isolate(),

"(function cloneProperty(source, key, target) {\n"

" if (key === 'Proxy') return;\n"

" try {\n"

" var desc = Object.getOwnPropertyDescriptor(source, key);\n"

" if (desc.value === source) desc.value = target;\n"

" Object.defineProperty(target, key, desc);\n"

" } catch (e) {\n"

" // Catch sealed properties errors\n"

" }\n"

"})");

Local<String> fname = FIXED_ONE_BYTE_STRING(env()->isolate(),

"binding:script");

Local<Script> script = Script::Compile(code, fname);

clone_property_method = Local<Function>::Cast(script->Run());

CHECK(clone_property_method->IsFunction());

}

Local<Value> args[] = { global, key, sandbox };

clone_property_method->Call(global, ARRAY_SIZE(args), args);

}

}

}

// This is an object that just keeps an internal pointer to this

// ContextifyContext. It's passed to the NamedPropertyHandler. If we

// pass the main JavaScript context object we're embedded in, then the

// NamedPropertyHandler will store a reference to it forever and keep it

// from getting gc'd.

Local<Value> CreateDataWrapper(Environment* env) {

EscapableHandleScope scope(env->isolate());

Local<Object> wrapper =

env->script_data_constructor_function()->NewInstance();

if (wrapper.IsEmpty())

return scope.Escape(Local<Value>::New(env->isolate(), Local<Value>()));

Wrap(wrapper, this);

return scope.Escape(wrapper);

}

Local<Context> CreateV8Context(Environment* env) {

EscapableHandleScope scope(env->isolate());

Local<FunctionTemplate> function_template =

FunctionTemplate::New(env->isolate());

function_template->SetHiddenPrototype(true);

Local<Object> sandbox = PersistentToLocal(env->isolate(), sandbox_);

function_template->SetClassName(sandbox->GetConstructorName());

Local<ObjectTemplate> object_template =

function_template->InstanceTemplate();

NamedPropertyHandlerConfiguration config(GlobalPropertyGetterCallback,

GlobalPropertySetterCallback,

GlobalPropertyQueryCallback,

GlobalPropertyDeleterCallback,

GlobalPropertyEnumeratorCallback,

CreateDataWrapper(env));

object_template->SetHandler(config);

Local<Context> ctx = Context::New(env->isolate(), nullptr, object_template);

CHECK(!ctx.IsEmpty());

ctx->SetSecurityToken(env->context()->GetSecurityToken());

env->AssignToContext(ctx);

return scope.Escape(ctx);

}

static void Init(Environment* env, Local<Object> target) {

Local<FunctionTemplate> function_template =

FunctionTemplate::New(env->isolate());

function_template->InstanceTemplate()->SetInternalFieldCount(1);

env->set_script_data_constructor_function(function_template->GetFunction());

env->SetMethod(target, "runInDebugContext", RunInDebugContext);

env->SetMethod(target, "makeContext", MakeContext);

env->SetMethod(target, "isContext", IsContext);

}

static void RunInDebugContext(const FunctionCallbackInfo<Value>& args) {

// Ensure that the debug context has an Environment assigned in case

// a fatal error is raised. The fatal exception handler in node.cc

// is not equipped to deal with contexts that don't have one and

// can't easily be taught that due to a deficiency in the V8 API:

// there is no way for the embedder to tell if the data index is

// in use.

struct ScopedEnvironment {

ScopedEnvironment(Local<Context> context, Environment* env)

: context_(context) {

const int index = Environment::kContextEmbedderDataIndex;

context->SetAlignedPointerInEmbedderData(index, env);

}

~ScopedEnvironment() {

const int index = Environment::kContextEmbedderDataIndex;

context_->SetAlignedPointerInEmbedderData(index, nullptr);

}

Local<Context> context_;

};

Local<String> script_source(args[0]->ToString(args.GetIsolate()));

if (script_source.IsEmpty())

return; // Exception pending.

Local<Context> debug_context = Debug::GetDebugContext();

if (debug_context.IsEmpty()) {

// Force-load the debug context.

Debug::GetMirror(args.GetIsolate()->GetCurrentContext(), args[0]);

debug_context = Debug::GetDebugContext();

CHECK(!debug_context.IsEmpty());

}

Environment* env = Environment::GetCurrent(args);

ScopedEnvironment env_scope(debug_context, env);

Context::Scope context_scope(debug_context);

Local<Script> script = Script::Compile(script_source);

if (script.IsEmpty())

return; // Exception pending.

args.GetReturnValue().Set(script->Run());

}

static void MakeContext(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

if (!args[0]->IsObject()) {

return env->ThrowTypeError("sandbox argument must be an object.");

}

Local<Object> sandbox = args[0].As<Object>();

Local<String> hidden_name =

FIXED_ONE_BYTE_STRING(env->isolate(), "_contextifyHidden");

// Don't allow contextifying a sandbox multiple times.

CHECK(sandbox->GetHiddenValue(hidden_name).IsEmpty());

TryCatch try_catch;

ContextifyContext* context = new ContextifyContext(env, sandbox);

if (try_catch.HasCaught()) {

try_catch.ReThrow();

return;

}

if (context->context().IsEmpty())

return;

Local<External> hidden_context = External::New(env->isolate(), context);

sandbox->SetHiddenValue(hidden_name, hidden_context);

}

static void IsContext(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

if (!args[0]->IsObject()) {

env->ThrowTypeError("sandbox must be an object");

return;

}

Local<Object> sandbox = args[0].As<Object>();

Local<String> hidden_name =

FIXED_ONE_BYTE_STRING(env->isolate(), "_contextifyHidden");

args.GetReturnValue().Set(!sandbox->GetHiddenValue(hidden_name).IsEmpty());

}

template <class T, Kind kind>

static void WeakCallback(const WeakCallbackData<T, ContextifyContext>& data) {

ContextifyContext* context = data.GetParameter();

if (kind == kSandbox)

context->sandbox_.ClearWeak();

else if (kind == kContext)

context->context_.ClearWeak();

else

context->proxy_global_.ClearWeak();

if (--context->references_ == 0)

delete context;

}

static ContextifyContext* ContextFromContextifiedSandbox(

Isolate* isolate,

const Local<Object>& sandbox) {

Local<String> hidden_name =

FIXED_ONE_BYTE_STRING(isolate, "_contextifyHidden");

Local<Value> context_external_v = sandbox->GetHiddenValue(hidden_name);

if (context_external_v.IsEmpty() || !context_external_v->IsExternal()) {

return nullptr;

}

Local<External> context_external = context_external_v.As<External>();

return static_cast<ContextifyContext*>(context_external->Value());

}

static void GlobalPropertyGetterCallback(

Local<Name> property,

const PropertyCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

ContextifyContext* ctx =

Unwrap<ContextifyContext>(args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

Local<Object> sandbox = PersistentToLocal(isolate, ctx->sandbox_);

MaybeLocal<Value> maybe_rv =

sandbox->GetRealNamedProperty(ctx->context(), property);

if (maybe_rv.IsEmpty()) {

Local<Object> proxy_global = PersistentToLocal(isolate,

ctx->proxy_global_);

maybe_rv = proxy_global->GetRealNamedProperty(ctx->context(), property);

}

Local<Value> rv;

if (maybe_rv.ToLocal(&rv)) {

if (rv == ctx->sandbox_)

rv = PersistentToLocal(isolate, ctx->proxy_global_);

args.GetReturnValue().Set(rv);

}

}

static void GlobalPropertySetterCallback(

Local<Name> property,

Local<Value> value,

const PropertyCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

ContextifyContext* ctx =

Unwrap<ContextifyContext>(args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

PersistentToLocal(isolate, ctx->sandbox_)->Set(property, value);

}

static void GlobalPropertyQueryCallback(

Local<Name> property,

const PropertyCallbackInfo<Integer>& args) {

Isolate* isolate = args.GetIsolate();

ContextifyContext* ctx =

Unwrap<ContextifyContext>(args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

Local<Object> sandbox = PersistentToLocal(isolate, ctx->sandbox_);

Maybe<PropertyAttribute> maybe_prop_attr =

sandbox->GetRealNamedPropertyAttributes(ctx->context(), property);

if (maybe_prop_attr.IsNothing()) {

Local<Object> proxy_global = PersistentToLocal(isolate,

ctx->proxy_global_);

maybe_prop_attr =

proxy_global->GetRealNamedPropertyAttributes(ctx->context(),

property);

}

if (maybe_prop_attr.IsJust()) {

PropertyAttribute prop_attr = maybe_prop_attr.FromJust();

args.GetReturnValue().Set(prop_attr);

}

}

static void GlobalPropertyDeleterCallback(

Local<Name> property,

const PropertyCallbackInfo<Boolean>& args) {

Isolate* isolate = args.GetIsolate();

ContextifyContext* ctx =

Unwrap<ContextifyContext>(args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

Local<Object> sandbox = PersistentToLocal(isolate, ctx->sandbox_);

Maybe<bool> success = sandbox->Delete(ctx->context(), property);

if (success.IsJust())

args.GetReturnValue().Set(success.FromJust());

}

static void GlobalPropertyEnumeratorCallback(

const PropertyCallbackInfo<Array>& args) {

ContextifyContext* ctx =

Unwrap<ContextifyContext>(args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

Local<Object> sandbox = PersistentToLocal(args.GetIsolate(), ctx->sandbox_);

args.GetReturnValue().Set(sandbox->GetPropertyNames());

}

private:

Persistent<UnboundScript> script_;

public:

static void Init(Environment* env, Local<Object> target) {

HandleScope scope(env->isolate());

Local<String> class_name =

FIXED_ONE_BYTE_STRING(env->isolate(), "ContextifyScript");

Local<FunctionTemplate> script_tmpl = env->NewFunctionTemplate(New);

script_tmpl->InstanceTemplate()->SetInternalFieldCount(1);

script_tmpl->SetClassName(class_name);

env->SetProtoMethod(script_tmpl, "runInContext", RunInContext);

env->SetProtoMethod(script_tmpl, "runInThisContext", RunInThisContext);

target->Set(class_name, script_tmpl->GetFunction());

env->set_script_context_constructor_template(script_tmpl);

}

// args: code, [options]

static void New(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

if (!args.IsConstructCall()) {

return env->ThrowError("Must call vm.Script as a constructor.");

}

ContextifyScript* contextify_script =

new ContextifyScript(env, args.This());

TryCatch try_catch;

Local<String> code = args[0]->ToString(env->isolate());

Local<String> filename = GetFilenameArg(args, 1);

bool display_errors = GetDisplayErrorsArg(args, 1);

if (try_catch.HasCaught()) {

try_catch.ReThrow();

return;

}

ScriptOrigin origin(filename);

ScriptCompiler::Source source(code, origin);

Local<UnboundScript> v8_script =

ScriptCompiler::CompileUnbound(env->isolate(), &source);

if (v8_script.IsEmpty()) {

if (display_errors) {

AppendExceptionLine(env, try_catch.Exception(), try_catch.Message());

}

try_catch.ReThrow();

return;

}

contextify_script->script_.Reset(env->isolate(), v8_script);

}

static bool InstanceOf(Environment* env, const Local<Value>& value) {

return !value.IsEmpty() &&

env->script_context_constructor_template()->HasInstance(value);

}

// args: [options]

static void RunInThisContext(const FunctionCallbackInfo<Value>& args) {

// Assemble arguments

TryCatch try_catch;

uint64_t timeout = GetTimeoutArg(args, 0);

bool display_errors = GetDisplayErrorsArg(args, 0);

if (try_catch.HasCaught()) {

try_catch.ReThrow();

return;

}

// Do the eval within this context

Environment* env = Environment::GetCurrent(args);

EvalMachine(env, timeout, display_errors, args, try_catch);

}

// args: sandbox, [options]

static void RunInContext(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

int64_t timeout;

bool display_errors;

// Assemble arguments

if (!args[0]->IsObject()) {

return env->ThrowTypeError(

"contextifiedSandbox argument must be an object.");

}

Local<Object> sandbox = args[0].As<Object>();

{

TryCatch try_catch;

timeout = GetTimeoutArg(args, 1);

display_errors = GetDisplayErrorsArg(args, 1);

if (try_catch.HasCaught()) {

try_catch.ReThrow();

return;

}

}

// Get the context from the sandbox

ContextifyContext* contextify_context =

ContextifyContext::ContextFromContextifiedSandbox(env->isolate(),

sandbox);

if (contextify_context == nullptr) {

return env->ThrowTypeError(

"sandbox argument must have been converted to a context.");

}

if (contextify_context->context().IsEmpty())

return;

{

TryCatch try_catch;

// Do the eval within the context

Context::Scope context_scope(contextify_context->context());

if (EvalMachine(contextify_context->env(),

timeout,

display_errors,

args,

try_catch)) {

contextify_context->CopyProperties();

}

if (try_catch.HasCaught()) {

try_catch.ReThrow();

return;

}

}

}

static int64_t GetTimeoutArg(const FunctionCallbackInfo<Value>& args,

const int i) {

if (args[i]->IsUndefined() || args[i]->IsString()) {

return -1;

}

if (!args[i]->IsObject()) {

Environment::ThrowTypeError(args.GetIsolate(),

"options must be an object");

return -1;

}

Local<String> key = FIXED_ONE_BYTE_STRING(args.GetIsolate(), "timeout");

Local<Value> value = args[i].As<Object>()->Get(key);

if (value->IsUndefined()) {

return -1;

}

int64_t timeout = value->IntegerValue();

if (timeout <= 0) {

Environment::ThrowRangeError(args.GetIsolate(),

"timeout must be a positive number");

return -1;

}

return timeout;

}

static bool GetDisplayErrorsArg(const FunctionCallbackInfo<Value>& args,

const int i) {

if (args[i]->IsUndefined() || args[i]->IsString()) {

return true;

}

if (!args[i]->IsObject()) {

Environment::ThrowTypeError(args.GetIsolate(),

"options must be an object");

return false;

}

Local<String> key = FIXED_ONE_BYTE_STRING(args.GetIsolate(),

"displayErrors");

Local<Value> value = args[i].As<Object>()->Get(key);

return value->IsUndefined() ? true : value->BooleanValue();

}

static Local<String> GetFilenameArg(const FunctionCallbackInfo<Value>& args,

const int i) {

Local<String> defaultFilename =

FIXED_ONE_BYTE_STRING(args.GetIsolate(), "evalmachine.<anonymous>");

if (args[i]->IsUndefined()) {

return defaultFilename;

}

if (args[i]->IsString()) {

return args[i].As<String>();

}

if (!args[i]->IsObject()) {

Environment::ThrowTypeError(args.GetIsolate(),

"options must be an object");

return Local<String>();

}

Local<String> key = FIXED_ONE_BYTE_STRING(args.GetIsolate(), "filename");

Local<Value> value = args[i].As<Object>()->Get(key);

if (value->IsUndefined())

return defaultFilename;

return value->ToString(args.GetIsolate());

}

static bool EvalMachine(Environment* env,

const int64_t timeout,

const bool display_errors,

const FunctionCallbackInfo<Value>& args,

TryCatch& try_catch) {

if (!ContextifyScript::InstanceOf(env, args.Holder())) {

env->ThrowTypeError(

"Script methods can only be called on script instances.");

return false;

}

ContextifyScript* wrapped_script = Unwrap<ContextifyScript>(args.Holder());

Local<UnboundScript> unbound_script =

PersistentToLocal(env->isolate(), wrapped_script->script_);

Local<Script> script = unbound_script->BindToCurrentContext();

Local<Value> result;

if (timeout != -1) {

Watchdog wd(env->isolate(), timeout);

result = script->Run();

} else {

result = script->Run();

}

if (try_catch.HasCaught() && try_catch.HasTerminated()) {

V8::CancelTerminateExecution(env->isolate());

env->ThrowError("Script execution timed out.");

try_catch.ReThrow();

return false;

}

if (result.IsEmpty()) {

// Error occurred during execution of the script.

if (display_errors) {

AppendExceptionLine(env, try_catch.Exception(), try_catch.Message());

}

try_catch.ReThrow();

return false;

}

args.GetReturnValue().Set(result);

return true;

}

ContextifyScript(Environment* env, Local<Object> object)

: BaseObject(env, object) {

MakeWeak<ContextifyScript>(this);

}

~ContextifyScript() override {

script_.Reset();

}

Local<Value> unused,

Local<Context> context) {

Environment* env = Environment::GetCurrent(context);

ContextifyContext::Init(env, target);

ContextifyScript::Init(env, target);