#include "node.h"

#include "node_internals.h"

#include "node_watchdog.h"

#include "base-object.h"

#include "base-object-inl.h"

#include "env.h"

#include "env-inl.h"

#include "util.h"

#include "util-inl.h"

#include "v8-debug.h"

namespace node {

using v8::AccessType;

using v8::Array;

using v8::Boolean;

using v8::Context;

using v8::Debug;

using v8::EscapableHandleScope;

using v8::External;

using v8::Function;

using v8::FunctionCallbackInfo;

using v8::FunctionTemplate;

using v8::HandleScope;

using v8::Integer;

using v8::Isolate;

using v8::Local;

using v8::Maybe;

using v8::MaybeLocal;

using v8::Name;

using v8::NamedPropertyHandlerConfiguration;

using v8::None;

using v8::Object;

using v8::ObjectTemplate;

using v8::Persistent;

using v8::PropertyAttribute;

using v8::PropertyCallbackInfo;

using v8::Script;

using v8::ScriptCompiler;

using v8::ScriptOrigin;

using v8::String;

using v8::TryCatch;

using v8::UnboundScript;

using v8::V8;

using v8::Value;

using v8::WeakCallbackInfo;

class ContextifyContext {

protected:

// V8 reserves the first field in context objects for the debugger. We use the

// second field to hold a reference to the sandbox object.

enum { kSandboxObjectIndex = 1 };

Environment* const env_;

Persistent<Context> context_;

public:

ContextifyContext(Environment* env, Local<Object> sandbox_obj) : env_(env) {

Local<Context> v8_context = CreateV8Context(env, sandbox_obj);

context_.Reset(env->isolate(), v8_context);

// Allocation failure or maximum call stack size reached

if (context_.IsEmpty())

return;

context_.SetWeak(this, WeakCallback, v8::WeakCallbackType::kParameter);

context_.MarkIndependent();

}

~ContextifyContext() {

context_.Reset();

}

inline Environment* env() const {

return env_;

}

inline Local<Context> context() const {

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

}

inline Local<Object> global_proxy() const {

return context()->Global();

}

inline Local<Object> sandbox() const {

return Local<Object>::Cast(context()->GetEmbedderData(kSandboxObjectIndex));

}

// 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_obj = 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_obj->HasOwnProperty(context, key).FromJust();

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_obj };

clone_property_method->Call(global, arraysize(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, Local<Object> sandbox_obj) {

EscapableHandleScope scope(env->isolate());

Local<FunctionTemplate> function_template =

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

function_template->SetHiddenPrototype(true);

function_template->SetClassName(sandbox_obj->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);

if (ctx.IsEmpty()) {

env->ThrowError("Could not instantiate context");

return Local<Context>();

}

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

// We need to tie the lifetime of the sandbox object with the lifetime of

// newly created context. We do this by making them hold references to each

// other. The context can directly hold a reference to the sandbox as an

// embedder data field. However, we cannot hold a reference to a v8::Context

// directly in an Object, we instead hold onto the new context's global

// object instead (which then has a reference to the context).

ctx->SetEmbedderData(kSandboxObjectIndex, sandbox_obj);

sandbox_obj->SetHiddenValue(

FIXED_ONE_BYTE_STRING(env->isolate(), "_contextifyHiddenGlobal"),

ctx->Global());

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) {

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

if (script_source.IsEmpty())

return; // Exception pending.

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

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

if (debug_context.IsEmpty()) {

// Force-load the debug context.

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

debug_context = Debug::GetDebugContext();

CHECK(!debug_context.IsEmpty());

// 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.

const int index = Environment::kContextEmbedderDataIndex;

debug_context->SetAlignedPointerInEmbedderData(index, 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());

}

static void WeakCallback(const WeakCallbackInfo<ContextifyContext>& data) {

ContextifyContext* context = data.GetParameter();

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) {

ContextifyContext* ctx;

ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

Local<Context> context = ctx->context();

Local<Object> sandbox = ctx->sandbox();

MaybeLocal<Value> maybe_rv =

sandbox->GetRealNamedProperty(context, property);

if (maybe_rv.IsEmpty()) {

maybe_rv =

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

}

Local<Value> rv;

if (maybe_rv.ToLocal(&rv)) {

if (rv == sandbox)

rv = ctx->global_proxy();

args.GetReturnValue().Set(rv);

}

}

static void GlobalPropertySetterCallback(

Local<Name> property,

Local<Value> value,

const PropertyCallbackInfo<Value>& args) {

ContextifyContext* ctx;

ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

ctx->sandbox()->Set(property, value);

}

static void GlobalPropertyQueryCallback(

Local<Name> property,

const PropertyCallbackInfo<Integer>& args) {

ContextifyContext* ctx;

ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

Local<Context> context = ctx->context();

Maybe<PropertyAttribute> maybe_prop_attr =

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

if (maybe_prop_attr.IsNothing()) {

maybe_prop_attr =

ctx->global_proxy()->GetRealNamedPropertyAttributes(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) {

ContextifyContext* ctx;

ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

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

if (success.IsJust())

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

}

static void GlobalPropertyEnumeratorCallback(

const PropertyCallbackInfo<Array>& args) {

ContextifyContext* ctx;

ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());

// Stil initializing

if (ctx->context_.IsEmpty())

return;

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

}

};

class ContextifyScript : public BaseObject {

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);

Local<Integer> lineOffset = GetLineOffsetArg(args, 1);

Local<Integer> columnOffset = GetColumnOffsetArg(args, 1);

bool display_errors = GetDisplayErrorsArg(args, 1);

if (try_catch.HasCaught()) {

try_catch.ReThrow();

return;

}

ScriptOrigin origin(filename, lineOffset, columnOffset);

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 Local<Integer> GetLineOffsetArg(

const FunctionCallbackInfo<Value>& args,

const int i) {

Local<Integer> defaultLineOffset = Integer::New(args.GetIsolate(), 0);

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

return defaultLineOffset;

}

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

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

return value->IsUndefined() ? defaultLineOffset : value->ToInteger();

}

static Local<Integer> GetColumnOffsetArg(

const FunctionCallbackInfo<Value>& args,

const int i) {

Local<Integer> defaultColumnOffset = Integer::New(args.GetIsolate(), 0);

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

return defaultColumnOffset;

}

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

"columnOffset");

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

return value->IsUndefined() ? defaultColumnOffset : value->ToInteger();

}

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;

ASSIGN_OR_RETURN_UNWRAP(&wrapped_script, args.Holder(), false);

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, 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();

}

};

void InitContextify(Local<Object> target,

Local<Value> unused,

Local<Context> context) {

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

ContextifyContext::Init(env, target);

ContextifyScript::Init(env, target);

}

} // namespace node

NODE_MODULE_CONTEXT_AWARE_BUILTIN(contextify, node::InitContextify);