chrome/browser/ash/input_method/ime_service_connector.cc

// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ash/input_method/ime_service_connector.h"

#include <memory>
#include <utility>

#include "base/files/file_util.h"
#include "chromeos/services/ime/constants.h"
#include "chromeos/services/ime/public/mojom/ime_service.mojom.h"
#include "chromeos/strings/grit/chromeos_strings.h"
#include "content/public/browser/service_process_host.h"
#include "net/base/load_flags.h"
#include "net/http/http_status_code.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "services/network/public/cpp/resource_request.h"
#include "services/network/public/cpp/shared_url_loader_factory.h"
#include "services/network/public/mojom/network_context.mojom.h"

namespace ash {
namespace input_method {

namespace {

constexpr net::NetworkTrafficAnnotationTag traffic_annotation =
    net::DefineNetworkTrafficAnnotation("ime_url_downloader", R"(
    semantics {
      sender: "IME Service Downloader"
      description:
        "When user selects a new input method in ChromeOS, it may request a"
        "corresponding language module downloaded if it does not exist."
      trigger: "User switches to an input method without language module."
      data:
        "The language module download URL. No user identifier is sent."
      destination: GOOGLE_OWNED_SERVICE
    }
    policy {
      cookies_allowed: NO
      policy_exception_justification:
        "Not implemented, considered not useful."
    })");

bool IsDownloadPathValid(const base::FilePath& file_path) {
  // Only non-empty, relative path which doesn't reference a parent is allowed.
  if (file_path.empty() || file_path.IsAbsolute() ||
      file_path.ReferencesParent())
    return false;

  // Target path must be restricted in the provided path.
  base::FilePath parent(chromeos::ime::kInputMethodsDirName);
  parent = parent.Append(chromeos::ime::kLanguageDataDirName);
  return parent.IsParent(file_path);
}

bool IsDownloadURLValid(const GURL& url) {
  // TODO(https://crbug.com/837156): Allowlist all URLs instead of some general
  // checks below.
  return url.SchemeIs(url::kHttpsScheme) &&
         url.DomainIs(chromeos::ime::kGoogleKeyboardDownloadDomain);
}

}  // namespace

ImeServiceConnector::ImeServiceConnector(Profile* profile)
    : profile_(profile), url_loader_factory_(profile->GetURLLoaderFactory()) {}

ImeServiceConnector::~ImeServiceConnector() = default;

void ImeServiceConnector::DownloadImeFileTo(
    const GURL& url,
    const base::FilePath& file_path,
    DownloadImeFileToCallback callback) {
  // For now, we don't allow the client to download multi files at same time.
  // Downloading request will be aborted and return empty before the current
  // downloading task exits.
  // TODO(https://crbug.com/971954): Support multi downloads.
  // Validate url and file_path, return an empty file path if not.
  if (url_loader_ || !IsDownloadURLValid(url) ||
      !IsDownloadPathValid(file_path)) {
    base::FilePath empty_path;
    std::move(callback).Run(empty_path);
    return;
  }

  auto resource_request = std::make_unique<network::ResourceRequest>();
  resource_request->url = url;
  resource_request->load_flags =
      net::LOAD_BYPASS_CACHE | net::LOAD_DISABLE_CACHE;
  // Disable cookies for this request.
  resource_request->credentials_mode = network::mojom::CredentialsMode::kOmit;

  url_loader_ = network::SimpleURLLoader::Create(std::move(resource_request),
                                                 traffic_annotation);
  // TODO(https://crbug.com/971954): Allow the client to specify the timeout.
  url_loader_->SetTimeoutDuration(base::Minutes(10));

  // Download the language module into a preconfigured ime folder of current
  // user's home which is allowed in IME service's sandbox.
  base::FilePath full_path = profile_->GetPath().Append(file_path);
  url_loader_->DownloadToFile(
      url_loader_factory_.get(),
      base::BindOnce(&ImeServiceConnector::OnFileDownloadComplete,
                     base::Unretained(this), std::move(callback)),
      full_path);
}

void ImeServiceConnector::SetupImeService(
    mojo::PendingReceiver<chromeos::ime::mojom::InputEngineManager> receiver) {
  if (!remote_service_) {
    content::ServiceProcessHost::Launch(
        remote_service_.BindNewPipeAndPassReceiver(),
        content::ServiceProcessHost::Options()
            .WithDisplayName(IDS_IME_SERVICE_DISPLAY_NAME)
            .Pass());
    remote_service_.reset_on_disconnect();

    platform_access_receiver_.reset();
    remote_service_->SetPlatformAccessProvider(
        platform_access_receiver_.BindNewPipeAndPassRemote());
  }

  remote_service_->BindInputEngineManager(std::move(receiver));
}

void ImeServiceConnector::OnFileDownloadComplete(
    DownloadImeFileToCallback client_callback,
    base::FilePath path) {
  std::move(client_callback).Run(path);
  url_loader_.reset();
  return;
}

}  // namespace input_method
}  // namespace ash