electron/shell/renderer/electron_renderer_client.cc

// Copyright (c) 2013 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

#include "shell/renderer/electron_renderer_client.h"

#include <string>
#include <vector>

#include "base/command_line.h"
#include "content/public/renderer/render_frame.h"
#include "electron/buildflags/buildflags.h"
#include "shell/common/api/electron_bindings.h"
#include "shell/common/asar/asar_util.h"
#include "shell/common/gin_helper/dictionary.h"
#include "shell/common/gin_helper/event_emitter_caller.h"
#include "shell/common/node_bindings.h"
#include "shell/common/node_includes.h"
#include "shell/common/node_util.h"
#include "shell/common/options_switches.h"
#include "shell/renderer/electron_render_frame_observer.h"
#include "shell/renderer/web_worker_observer.h"
#include "third_party/blink/public/common/web_preferences/web_preferences.h"
#include "third_party/blink/public/web/web_document.h"
#include "third_party/blink/public/web/web_local_frame.h"

namespace electron {

namespace {

bool IsDevToolsExtension(content::RenderFrame* render_frame) {
  return static_cast<GURL>(render_frame->GetWebFrame()->GetDocument().Url())
      .SchemeIs("chrome-extension");
}

}  // namespace

// static
ElectronRendererClient* ElectronRendererClient::self_ = nullptr;

ElectronRendererClient::ElectronRendererClient()
    : node_bindings_(
          NodeBindings::Create(NodeBindings::BrowserEnvironment::kRenderer)),
      electron_bindings_(new ElectronBindings(node_bindings_->uv_loop())) {
  DCHECK(!self_) << "Cannot have two ElectronRendererClient";
  self_ = this;
}

ElectronRendererClient::~ElectronRendererClient() {
  asar::ClearArchives();
}

// static
ElectronRendererClient* ElectronRendererClient::Get() {
  DCHECK(self_);
  return self_;
}

void ElectronRendererClient::RenderFrameCreated(
    content::RenderFrame* render_frame) {
  new ElectronRenderFrameObserver(render_frame, this);
  RendererClientBase::RenderFrameCreated(render_frame);
}

void ElectronRendererClient::RunScriptsAtDocumentStart(
    content::RenderFrame* render_frame) {
  RendererClientBase::RunScriptsAtDocumentStart(render_frame);
  // Inform the document start pharse.
  v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
  node::Environment* env = GetEnvironment(render_frame);
  if (env)
    gin_helper::EmitEvent(env->isolate(), env->process_object(),
                          "document-start");
}

void ElectronRendererClient::RunScriptsAtDocumentEnd(
    content::RenderFrame* render_frame) {
  RendererClientBase::RunScriptsAtDocumentEnd(render_frame);
  // Inform the document end pharse.
  v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
  node::Environment* env = GetEnvironment(render_frame);
  if (env)
    gin_helper::EmitEvent(env->isolate(), env->process_object(),
                          "document-end");
}

void ElectronRendererClient::DidCreateScriptContext(
    v8::Handle<v8::Context> renderer_context,
    content::RenderFrame* render_frame) {
  RendererClientBase::DidCreateScriptContext(renderer_context, render_frame);

  // TODO(zcbenz): Do not create Node environment if node integration is not
  // enabled.

  // Only load node if we are a main frame or a devtools extension
  // unless node support has been explicitly enabled for sub frames
  auto prefs = render_frame->GetBlinkPreferences();
  bool reuse_renderer_processes_enabled =
      prefs.disable_electron_site_instance_overrides;
  // Consider the window not "opened" if it does not have an Opener, or if a
  // user has manually opted in to leaking node in the renderer
  bool is_not_opened =
      !render_frame->GetWebFrame()->Opener() || prefs.node_leakage_in_renderers;
  // Consider this the main frame if it is both a Main Frame and it wasn't
  // opened.  We allow an opened main frame to have node if renderer process
  // reuse is enabled as that will correctly free node environments prevent a
  // leak in child windows.
  bool is_main_frame = render_frame->IsMainFrame() &&
                       (is_not_opened || reuse_renderer_processes_enabled);
  bool is_devtools = IsDevToolsExtension(render_frame);
  bool allow_node_in_subframes = prefs.node_integration_in_sub_frames;
  bool should_load_node =
      (is_main_frame || is_devtools || allow_node_in_subframes) &&
      !IsWebViewFrame(renderer_context, render_frame);
  if (!should_load_node) {
    return;
  }

  injected_frames_.insert(render_frame);

  if (!node_integration_initialized_) {
    node_integration_initialized_ = true;
    node_bindings_->Initialize();
    node_bindings_->PrepareMessageLoop();
  } else if (reuse_renderer_processes_enabled) {
    node_bindings_->PrepareMessageLoop();
  }

  // Setup node tracing controller.
  if (!node::tracing::TraceEventHelper::GetAgent())
    node::tracing::TraceEventHelper::SetAgent(node::CreateAgent());

  // Setup node environment for each window.
  bool initialized = node::InitializeContext(renderer_context);
  CHECK(initialized);

  node::Environment* env =
      node_bindings_->CreateEnvironment(renderer_context, nullptr);

  // If we have disabled the site instance overrides we should prevent loading
  // any non-context aware native module
  if (reuse_renderer_processes_enabled)
    env->set_force_context_aware(true);
  env->set_warn_context_aware(true);

  environments_.insert(env);

  // Add Electron extended APIs.
  electron_bindings_->BindTo(env->isolate(), env->process_object());
  AddRenderBindings(env->isolate(), env->process_object());
  gin_helper::Dictionary process_dict(env->isolate(), env->process_object());
  process_dict.SetReadOnly("isMainFrame", render_frame->IsMainFrame());

  // Load everything.
  node_bindings_->LoadEnvironment(env);

  if (node_bindings_->uv_env() == nullptr) {
    // Make uv loop being wrapped by window context.
    node_bindings_->set_uv_env(env);

    // Give the node loop a run to make sure everything is ready.
    node_bindings_->RunMessageLoop();
  }
}

void ElectronRendererClient::WillReleaseScriptContext(
    v8::Handle<v8::Context> context,
    content::RenderFrame* render_frame) {
  if (injected_frames_.erase(render_frame) == 0)
    return;

  node::Environment* env = node::Environment::GetCurrent(context);
  if (environments_.erase(env) == 0)
    return;

  gin_helper::EmitEvent(env->isolate(), env->process_object(), "exit");

  // The main frame may be replaced.
  if (env == node_bindings_->uv_env())
    node_bindings_->set_uv_env(nullptr);

  // Destroy the node environment.  We only do this if node support has been
  // enabled for sub-frames to avoid a change-of-behavior / introduce crashes
  // for existing users.
  // We also do this if we have disable electron site instance overrides to
  // avoid memory leaks
  auto prefs = render_frame->GetBlinkPreferences();
  if (prefs.node_integration_in_sub_frames ||
      prefs.disable_electron_site_instance_overrides) {
    node::FreeEnvironment(env);
    if (env == node_bindings_->uv_env())
      node::FreeIsolateData(node_bindings_->isolate_data());
  }

  // ElectronBindings is tracking node environments.
  electron_bindings_->EnvironmentDestroyed(env);
}

bool ElectronRendererClient::ShouldFork(blink::WebLocalFrame* frame,
                                        const GURL& url,
                                        const std::string& http_method,
                                        bool is_initial_navigation,
                                        bool is_server_redirect) {
  // Handle all the navigations and reloads in browser.
  // FIXME We only support GET here because http method will be ignored when
  // the OpenURLFromTab is triggered, which means form posting would not work,
  // we should solve this by patching Chromium in future.
  return http_method == "GET";
}

void ElectronRendererClient::WorkerScriptReadyForEvaluationOnWorkerThread(
    v8::Local<v8::Context> context) {
  // TODO(loc): Note that this will not be correct for in-process child windows
  // with webPreferences that have a different value for nodeIntegrationInWorker
  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kNodeIntegrationInWorker)) {
    WebWorkerObserver::GetCurrent()->WorkerScriptReadyForEvaluation(context);
  }
}

void ElectronRendererClient::WillDestroyWorkerContextOnWorkerThread(
    v8::Local<v8::Context> context) {
  // TODO(loc): Note that this will not be correct for in-process child windows
  // with webPreferences that have a different value for nodeIntegrationInWorker
  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kNodeIntegrationInWorker)) {
    WebWorkerObserver::GetCurrent()->ContextWillDestroy(context);
  }
}

void ElectronRendererClient::SetupMainWorldOverrides(
    v8::Handle<v8::Context> context,
    content::RenderFrame* render_frame) {
  auto prefs = render_frame->GetBlinkPreferences();
  // We only need to run the isolated bundle if webview is enabled
  if (!prefs.webview_tag)
    return;
  // Setup window overrides in the main world context
  // Wrap the bundle into a function that receives the isolatedWorld as
  // an argument.
  auto* isolate = context->GetIsolate();
  std::vector<v8::Local<v8::String>> isolated_bundle_params = {
      node::FIXED_ONE_BYTE_STRING(isolate, "nodeProcess"),
      node::FIXED_ONE_BYTE_STRING(isolate, "isolatedWorld")};

  auto* env = GetEnvironment(render_frame);
  DCHECK(env);

  std::vector<v8::Local<v8::Value>> isolated_bundle_args = {
      env->process_object(),
      GetContext(render_frame->GetWebFrame(), isolate)->Global()};

  util::CompileAndCall(context, "electron/js2c/isolated_bundle",
                       &isolated_bundle_params, &isolated_bundle_args, nullptr);
}

node::Environment* ElectronRendererClient::GetEnvironment(
    content::RenderFrame* render_frame) const {
  if (injected_frames_.find(render_frame) == injected_frames_.end())
    return nullptr;
  v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
  auto context =
      GetContext(render_frame->GetWebFrame(), v8::Isolate::GetCurrent());
  node::Environment* env = node::Environment::GetCurrent(context);
  if (environments_.find(env) == environments_.end())
    return nullptr;
  return env;
}

}  // namespace electron