content/browser/webui/web_ui_impl.cc

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/webui/web_ui_impl.h"

#include <stddef.h>

#include <string>
#include <string_view>
#include <utility>

#include "base/containers/flat_map.h"
#include "base/debug/dump_without_crashing.h"
#include "base/feature_list.h"
#include "base/functional/callback_helpers.h"
#include "base/json/json_writer.h"
#include "base/strings/strcat.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/values.h"
#include "build/build_config.h"
#include "content/browser/child_process_security_policy_impl.h"
#include "content/browser/renderer_host/dip_util.h"
#include "content/browser/renderer_host/frame_tree.h"
#include "content/browser/renderer_host/navigation_request.h"
#include "content/browser/renderer_host/render_frame_host_impl.h"
#include "content/browser/renderer_host/render_process_host_impl.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/browser/web_contents/web_contents_view.h"
#include "content/browser/webui/url_data_manager_backend.h"
#include "content/browser/webui/web_ui_controller_factory_registry.h"
#include "content/browser/webui/web_ui_data_source_impl.h"
#include "content/browser/webui/web_ui_main_frame_observer.h"
#include "content/common/features.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_ui_browser_interface_broker_registry.h"
#include "content/public/browser/web_ui_controller.h"
#include "content/public/browser/web_ui_message_handler.h"
#include "content/public/common/bindings_policy.h"
#include "content/public/common/content_client.h"
#include "content/public/common/content_features.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/url_constants.h"
#include "services/service_manager/public/cpp/interface_provider.h"
#include "third_party/blink/public/mojom/loader/local_resource_loader_config.mojom.h"
#include "ui/base/webui/jstemplate_builder.h"

namespace content {

namespace {

template <typename Range>
std::u16string GetJavascriptCallImpl(std::string_view function_name,
                                     const Range& args) {
  std::vector<std::u16string> json_args;
  for (const auto& arg : args) {
    json_args.push_back(base::UTF8ToUTF16(*base::WriteJson(arg)));
  }

  std::u16string result(base::ASCIIToUTF16(function_name));
  result.push_back('(');
  result.append(base::JoinString(json_args, u","));
  result.push_back(')');
  result.push_back(';');
  return result;
}

// Populates `path_to_resource_map` with resources from `webui_data_source`.
// This includes both IDR resources (mapped to resource IDs) and generated
// resources (mapped to response bodies).
void PopulateLocalResourceMap(
    const WebUIDataSourceImpl& webui_data_source,
    base::flat_map<std::string, blink::mojom::LocalResourceValuePtr>&
        path_to_resource_map) {
  // Add IDR resources.
  for (const auto& [path, resource_id] : webui_data_source.path_to_idr_map()) {
    path_to_resource_map[path] =
        blink::mojom::LocalResourceValue::NewResourceId(resource_id);
  }

  if (!base::FeatureList::IsEnabled(
          features::kWebUIInProcessResourceLoadingV2)) {
    return;
  }

  // Add generated resources.
  base::flat_map<std::string, std::string> generated_resources;
  webui_data_source.PopulateWebUIResources(generated_resources);

  for (auto& [path, content] : generated_resources) {
    // Ensures dynamic resources, e.g., string.m.js, do not have a resource id.
    CHECK(path_to_resource_map.find(path) == path_to_resource_map.end());
    path_to_resource_map[path] =
        blink::mojom::LocalResourceValue::NewResponseBody(std::move(content));
  }
}

// Returns true if the data source from `origin` should be included for a WebUI
// with `current_origin`.
// For performance, a WebUI page should only receives data from its own data
// sources and shared resources.
// TODO(crbug.com/459528908): Allow configuring this from URLDataSource.
bool ShouldIncludeDataSource(const url::Origin& origin,
                             const url::Origin& current_origin) {
  // We only support data sources that serve URLs of the form: chrome://*
  if (origin.scheme() != kChromeUIScheme) {
    return false;
  }

  if (!base::FeatureList::IsEnabled(
          features::kWebUIInProcessResourceLoadingV2)) {
    return true;
  }

  return origin == current_origin || origin.host() == kChromeUIResourcesHost ||
         origin.host() == kChromeUIThemeHost;
}

// Helper to add a single data source to the config.
void AddDataSourceToConfig(
    WebUIDataSourceImpl* webui_data_source,
    const url::Origin& current_origin,
    blink::mojom::LocalResourceLoaderConfig* loader_config) {
  url::Origin origin = webui_data_source->GetOrigin();

  if (!ShouldIncludeDataSource(origin, current_origin)) {
    return;
  }

  auto loader_source = blink::mojom::LocalResourceSource::New();
  webui_data_source->EnsureLoadTimeDataDefaultsAdded();
  loader_source->headers =
      URLDataManagerBackend::GetHeaders(webui_data_source, GURL("/"), "")
          ->raw_headers();
  loader_source->should_replace_i18n_in_js =
      webui_data_source->source()->ShouldReplaceI18nInJS();
  PopulateLocalResourceMap(*webui_data_source,
                           loader_source->path_to_resource_map);
  loader_source->replacement_strings.insert(
      webui_data_source->source()->GetReplacements()->begin(),
      webui_data_source->source()->GetReplacements()->end());
  loader_config->sources[origin] = std::move(loader_source);
}

blink::mojom::LocalResourceLoaderConfigPtr CreateLocalResourceLoaderConfig(
    URLDataManagerBackend* data_backend,
    const url::Origin& current_origin,
    WebUIController* controller) {
  auto loader_config = blink::mojom::LocalResourceLoaderConfig::New();

  // 1. Process data sources from the backend.
  for (auto const& [source_name, data_source] : data_backend->data_sources()) {
    // For a data source to be useful in the renderer process, it must have a
    // map from path to resource ID. Only WebUIDataSourceImpls have a map from
    // path to resource ID or a map from path to response.
    // Most URLDataSources are not WebUIDataSourceImpls, e.g. favicon, image,
    // etc.
    if (!data_source->IsWebUIDataSourceImpl()) {
      continue;
    }
    auto* webui_data_source =
        static_cast<WebUIDataSourceImpl*>(data_source.get());
    AddDataSourceToConfig(webui_data_source, current_origin,
                          loader_config.get());
  }

  // 2. Process shared data sources provided by the controller.
  if (base::FeatureList::IsEnabled(
          features::kWebUIInProcessResourceLoadingV2) &&
      controller) {
    controller->PopulateLocalResourceLoaderConfig(loader_config.get(),
                                                  current_origin);
  }

  return loader_config;
}

bool IsForTestMessage(const std::string& message) {
  return base::EndsWith(message, "ForTest") ||
         base::EndsWith(message, "ForTesting");
}

}  // namespace

const WebUI::TypeID WebUI::kNoWebUI = nullptr;

// static
std::u16string WebUI::GetJavascriptCall(
    std::string_view function_name,
    base::span<const base::ValueView> arg_list) {
  return GetJavascriptCallImpl(function_name, arg_list);
}

// static
std::u16string WebUI::GetJavascriptCall(std::string_view function_name,
                                        const base::Value::List& arg_list) {
  return GetJavascriptCallImpl(function_name, arg_list);
}

WebUIImpl::WebUIImpl(WebContents* web_contents)
    : requestable_schemes_({kChromeUIScheme, url::kFileScheme}),
      web_contents_(web_contents),
      web_contents_observer_(
          std::make_unique<WebUIMainFrameObserver>(this, web_contents_)) {
  DCHECK(web_contents_);
}

WebUIImpl::WebUIImpl(NavigationRequest* request)
    : WebUIImpl(
          WebContents::FromFrameTreeNodeId(request->GetFrameTreeNodeId())) {}

WebUIImpl::~WebUIImpl() {
  // Delete the controller first, since it may also be keeping a pointer to some
  // of the handlers and can call them at destruction.
  // Note: Calling this might delete |web_content_| and |frame_host_|. The two
  // pointers are now potentially dangling.
  // See https://crbug.com/1308391
  broker_.reset();
  controller_.reset();

  remote_.reset();
  receiver_.reset();
}

void WebUIImpl::SetProperty(const std::string& name, const std::string& value) {
  DCHECK(remote_);
  remote_->SetProperty(name, value);
}

void WebUIImpl::Send(const std::string& message, base::Value::List args) {
  const GURL& source_url = frame_host_->GetLastCommittedURL();
  if (!ChildProcessSecurityPolicyImpl::GetInstance()->HasWebUIBindings(
          frame_host_->GetProcess()->GetDeprecatedID()) ||
      !WebUIControllerFactoryRegistry::GetInstance()->IsURLAcceptableForWebUI(
          web_contents_->GetBrowserContext(), source_url)) {
    bad_message::ReceivedBadMessage(
        frame_host_->GetProcess(),
        bad_message::WEBUI_SEND_FROM_UNAUTHORIZED_PROCESS);
    return;
  }

  if (base::EndsWith(message, "RequiringGesture",
                     base::CompareCase::SENSITIVE) &&
      !web_contents_->HasRecentInteraction()) {
    LOG(ERROR) << message << " received without recent user interaction";
    return;
  }

  ProcessWebUIMessage(source_url, message, std::move(args));
}

void WebUIImpl::SetRenderFrameHost(RenderFrameHost* render_frame_host) {
  frame_host_ =
      static_cast<RenderFrameHostImpl*>(render_frame_host)->GetWeakPtr();
  // Assert that we can only open WebUI for the active or speculative pages.
  DCHECK(frame_host_->lifecycle_state() ==
             RenderFrameHostImpl::LifecycleStateImpl::kActive ||
         frame_host_->lifecycle_state() ==
             RenderFrameHostImpl::LifecycleStateImpl::kSpeculative);
}

void WebUIImpl::WebUIRenderFrameCreated(RenderFrameHost* render_frame_host,
                                        const url::Origin& origin_to_commit) {
  controller_->WebUIRenderFrameCreated(render_frame_host);

#if BUILDFLAG(LOAD_WEBUI_FROM_DISK)
  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kLoadWebUIfromDisk)) {
    return;
  }
#endif

  if (base::FeatureList::IsEnabled(features::kWebUIInProcessResourceLoading)) {
    CHECK(frame_host_);
    frame_host_->UpdateLocalResourceLoader(
        GetLocalResourceLoaderConfig(origin_to_commit));
  }
}

void WebUIImpl::RenderFrameHostUnloading() {
  DisallowJavascriptOnAllHandlers();
}

void WebUIImpl::RenderFrameDeleted() {
  DisallowJavascriptOnAllHandlers();
}

void WebUIImpl::SetUpMojoConnection() {
  // TODO(nasko): WebUI mojo might be useful to be registered for
  // subframes as well, though at this time there is no such usage but currently
  // this is expected to be called only for outermost main frames.
  if (frame_host_->GetParentOrOuterDocument())
    return;

  frame_host_->GetFrameBindingsControl()->BindWebUI(
      remote_.BindNewEndpointAndPassReceiver(),
      receiver_.BindNewEndpointAndPassRemote());
}

WebUIBrowserInterfaceBrokerRegistry& GetRegistryFor(
    WebUIController& controller) {
  switch (controller.GetTrustPolicy()) {
    case WebUIController::TrustPolicy::kTrusted:
      return WebUIBrowserInterfaceBrokerRegistry::GetTrustedRegistry();
    case WebUIController::TrustPolicy::kUntrusted:
      return WebUIBrowserInterfaceBrokerRegistry::GetUntrustedRegistry();
  }
}

void WebUIImpl::SetUpMojoInterfaceBroker() {
  CHECK(GetController()) << "controller has not been set yet";

  broker_ =
      GetRegistryFor(*GetController()).CreateInterfaceBroker(*GetController());
  if (broker_) {
    RenderFrameHostImpl* rfh =
        static_cast<RenderFrameHostImpl*>(GetRenderFrameHost());
    // If this WebUIController has a per-WebUI interface broker, create the
    // broker's remote and ask renderer to use it.
    rfh->EnableMojoJsBindingsWithBroker(broker_->BindNewPipeAndPassRemote());
  }
}

void WebUIImpl::TearDownMojoConnection() {
  // This is expected to be called only for outermost main frames.
  if (frame_host_->GetParentOrOuterDocument())
    return;

  remote_.reset();
  receiver_.reset();
}

WebContents* WebUIImpl::GetWebContents() {
  return web_contents_;
}

float WebUIImpl::GetDeviceScaleFactor() {
  return GetScaleFactorForView(web_contents_->GetRenderWidgetHostView());
}

const std::u16string& WebUIImpl::GetOverriddenTitle() {
  return overridden_title_;
}

void WebUIImpl::OverrideTitle(const std::u16string& title) {
  overridden_title_ = title;
}

BindingsPolicySet WebUIImpl::GetBindings() {
  return bindings_;
}

void WebUIImpl::SetBindings(BindingsPolicySet bindings) {
  bindings_ = bindings;
}

const std::vector<std::string>& WebUIImpl::GetRequestableSchemes() {
  return requestable_schemes_;
}

void WebUIImpl::AddRequestableScheme(const char* scheme) {
  requestable_schemes_.push_back(scheme);
}

WebUIController* WebUIImpl::GetController() {
  return controller_.get();
}

RenderFrameHost* WebUIImpl::GetRenderFrameHost() {
  return frame_host_.get();
}

bool WebUIImpl::HasRenderFrameHost() const {
  return !!frame_host_;
}

void WebUIImpl::SetController(std::unique_ptr<WebUIController> controller) {
  CHECK(controller);
  CHECK(!controller_) << "controller cannot be set twice";
  controller_ = std::move(controller);
}

bool WebUIImpl::CanCallJavascript() {
  return (ChildProcessSecurityPolicyImpl::GetInstance()->HasWebUIBindings(
              frame_host_->GetProcess()->GetDeprecatedID()) ||
          // It's possible to load about:blank in a Web UI renderer.
          // See http://crbug.com/42547
          frame_host_->GetLastCommittedURL().spec() == url::kAboutBlankURL);
}

void WebUIImpl::CallJavascriptFunctionUnsafe(
    std::string_view function_name,
    base::span<const base::ValueView> args) {
  DCHECK(base::IsStringASCII(function_name));
  ExecuteJavascript(GetJavascriptCall(function_name, args));
}

void WebUIImpl::RegisterMessageCallback(std::string_view message,
                                        MessageCallback callback) {
  message_callbacks_.emplace(message, std::move(callback));
}

void WebUIImpl::ProcessWebUIMessage(const GURL& source_url,
                                    const std::string& message,
                                    base::Value::List args) {
  if (controller_->OverrideHandleWebUIMessage(source_url, message, args))
    return;

  auto callback_pair = message_callbacks_.find(message);
  if (callback_pair != message_callbacks_.end()) {
    // Forward this message and content on.
    callback_pair->second.Run(args);
    return;
  }

  if (!IsForTestMessage(message)) {
    DUMP_WILL_BE_NOTREACHED() << "Unhandled chrome.send(\"" << message << "\", "
                              << args << "); from " << source_url;
  }
}

std::vector<std::unique_ptr<WebUIMessageHandler>>*
WebUIImpl::GetHandlersForTesting() {
  return &handlers_;
}

// WebUIImpl, protected: -------------------------------------------------------

void WebUIImpl::AddMessageHandler(
    std::unique_ptr<WebUIMessageHandler> handler) {
  DCHECK(!handler->web_ui());
  handler->set_web_ui(this);
  handler->RegisterMessages();
  handlers_.push_back(std::move(handler));
}

void WebUIImpl::ExecuteJavascript(const std::u16string& javascript) {
  // Silently ignore the request. Would be nice to clean-up WebUI so we
  // could turn this into a CHECK(). http://crbug.com/516690.
  if (!CanCallJavascript())
    return;

  frame_host_->ExecuteJavaScript(javascript, base::NullCallback());
}

void WebUIImpl::DisallowJavascriptOnAllHandlers() {
  for (const std::unique_ptr<WebUIMessageHandler>& handler : handlers_)
    handler->DisallowJavascript();
}

blink::mojom::LocalResourceLoaderConfigPtr
WebUIImpl::GetLocalResourceLoaderConfig(const url::Origin& origin_to_commit) {
  URLDataManagerBackend* data_backend =
      URLDataManagerBackend::GetForBrowserContext(
          web_contents_->GetBrowserContext());
  return CreateLocalResourceLoaderConfig(data_backend, origin_to_commit,
                                         controller_.get());
}

// static
blink::mojom::LocalResourceLoaderConfigPtr
WebUIImpl::GetLocalResourceLoaderConfigForTesting(
    URLDataManagerBackend* data_backend,
    const url::Origin& current_origin,
    WebUIController* controller) {
  return CreateLocalResourceLoaderConfig(data_backend, current_origin,
                                         controller);
}

}  // namespace content