Implement a policy to autologin a public account.

chrome/browser/chromeos/login/existing_user_controller.cc

 // Copyright (c) 2012 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/chromeos/login/existing_user_controller.h"
 
 #include <vector>
 
+#include "ash/shell.h"
+#include "ash/wm/user_activity_detector.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
@@ skipping 117 matching lines @@
 ExistingUserController::ExistingUserController(LoginDisplayHost* host)
     : login_status_consumer_(NULL),
       host_(host),
       login_display_(host_->CreateLoginDisplay(this)),
       num_login_attempts_(0),
       cros_settings_(CrosSettings::Get()),
       weak_factory_(this),
       offline_failed_(false),
       is_login_in_progress_(false),
       password_changed_(false),
-      do_auto_enrollment_(false) {
+      do_auto_enrollment_(false),
+      signin_screen_ready_(false) {
   DCHECK(current_controller_ == NULL);
   current_controller_ = this;
 
   registrar_.Add(this,
                  chrome::NOTIFICATION_LOGIN_USER_IMAGE_CHANGED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_USER_LIST_CHANGED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_AUTH_SUPPLIED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_SESSION_STARTED,
                  content::NotificationService::AllSources());
   cros_settings_->AddSettingsObserver(kAccountsPrefShowUserNamesOnSignIn, this);
   cros_settings_->AddSettingsObserver(kAccountsPrefAllowNewUser, this);
   cros_settings_->AddSettingsObserver(kAccountsPrefAllowGuest, this);
   cros_settings_->AddSettingsObserver(kAccountsPrefUsers, this);
+  cros_settings_->AddSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginId,
+      this);
+  cros_settings_->AddSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+      this);
 }
 
 void ExistingUserController::Init(const UserList& users) {
   time_init_ = base::Time::Now();
   UpdateLoginDisplay(users);
+  ConfigurePublicSessionAutoLogin();
 
   LoginUtils::Get()->PrewarmAuthentication();
   DBusThreadManager::Get()->GetSessionManagerClient()->EmitLoginPromptReady();
 }
 
 void ExistingUserController::UpdateLoginDisplay(const UserList& users) {
   bool show_users_on_signin;
   UserList filtered_users;
 
   cros_settings_->GetBoolean(kAccountsPrefShowUserNamesOnSignIn,
@@ skipping 40 matching lines @@
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   if (type == chrome::NOTIFICATION_SESSION_STARTED) {
     // Stop listening to any notification once session has started.
     // Sign in screen objects are marked for deletion with DeleteSoon so
     // make sure no object would be used after session has started.
     // http://crbug.com/125276
     registrar_.RemoveAll();
     return;
   }
+  if (type == chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED) {
+    std::string setting = *content::Details<const std::string>(details).ptr();

[bartfab (slow), 2013/02/25 16:51:23]

Nit: I would make this a "const std::string"

[dconnelly, 2013/02/26 18:04:15]

Done.

+    if (setting == kAccountsPrefDeviceLocalAccountAutoLoginId ||
+        setting == kAccountsPrefDeviceLocalAccountAutoLoginDelay) {
+      ConfigurePublicSessionAutoLogin();
+    }
+  }
   if (type == chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED ||
       type == chrome::NOTIFICATION_USER_LIST_CHANGED) {
     if (host_ != NULL) {
       // Signed settings or user list changed. Notify views and update them.
       UpdateLoginDisplay(chromeos::UserManager::Get()->GetUsers());
       return;
     }
   }
   if (type == chrome::NOTIFICATION_AUTH_SUPPLIED) {
     // Possibly the user has authenticated against a proxy server and we might
@@ skipping 29 matching lines @@
 // ExistingUserController, private:
 
 ExistingUserController::~ExistingUserController() {
   LoginUtils::Get()->DelegateDeleted(this);
 
   cros_settings_->RemoveSettingsObserver(kAccountsPrefShowUserNamesOnSignIn,
                                          this);
   cros_settings_->RemoveSettingsObserver(kAccountsPrefAllowNewUser, this);
   cros_settings_->RemoveSettingsObserver(kAccountsPrefAllowGuest, this);
   cros_settings_->RemoveSettingsObserver(kAccountsPrefUsers, this);
+  cros_settings_->RemoveSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginId,
+      this);
+  cros_settings_->RemoveSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+      this);
+
+  if (ash::Shell::HasInstance())
+    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
 
   if (current_controller_ == this) {
     current_controller_ = NULL;
   } else {
     NOTREACHED() << "More than one controller are alive.";
   }
   DCHECK(login_display_.get());
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 34 matching lines @@
   // TODO(nkostylev): A11y message.
 }
 
 void ExistingUserController::CompleteLogin(const std::string& username,
                                            const std::string& password) {
   if (!host_) {
     // Complete login event was generated already from UI. Ignore notification.
     return;
   }
 
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable UI while loading user profile.
   login_display_->SetUIEnabled(false);
 
   if (!time_init_.is_null()) {
     base::TimeDelta delta = base::Time::Now() - time_init_;
     UMA_HISTOGRAM_MEDIUM_TIMES("Login.PromptToCompleteLoginTime", delta);
     time_init_ = base::Time();  // Reset to null.
   }
 
   host_->OnCompleteLogin();
@@ skipping 36 matching lines @@
 }
 
 string16 ExistingUserController::GetConnectedNetworkName() {
   return GetCurrentNetworkName();
 }
 
 void ExistingUserController::Login(const std::string& username,
                                    const std::string& password) {
   if (username.empty() || password.empty())
     return;
+
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
   BootTimesLoader::Get()->RecordLoginAttempted();
 
   if (last_login_attempt_username_ != username) {
     last_login_attempt_username_ = username;
     num_login_attempts_ = 0;
     // Also reset state variables, which are used to determine password change.
     offline_failed_ = false;
@@ skipping 27 matching lines @@
           UserManager::kLocallyManagedUserDomain) {
     login_performer_->LoginAsLocallyManagedUser(username, password);
   } else {
     login_performer_->PerformLogin(username, password, auth_mode);
   }
   accessibility::MaybeSpeak(
       l10n_util::GetStringUTF8(IDS_CHROMEOS_ACC_LOGIN_SIGNING_IN));
 }
 
 void ExistingUserController::LoginAsRetailModeUser() {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
   // TODO(rkc): Add a CHECK to make sure retail mode logins are allowed once
   // the enterprise policy wiring is done for retail mode.
 
   // Only one instance of LoginPerformer should exist at a time.
   login_performer_.reset(NULL);
   login_performer_.reset(new LoginPerformer(this));
   is_login_in_progress_ = true;
   login_performer_->LoginRetailMode();
   accessibility::MaybeSpeak(
       l10n_util::GetStringUTF8(IDS_CHROMEOS_ACC_LOGIN_SIGNIN_DEMOUSER));
 }
 
 void ExistingUserController::LoginAsGuest() {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
   CrosSettingsProvider::TrustedStatus status =
       cros_settings_->PrepareTrustedValues(
           base::Bind(&ExistingUserController::LoginAsGuest,
                      weak_factory_.GetWeakPtr()));
   // Must not proceed without signature verification.
   if (status == CrosSettingsProvider::PERMANENTLY_UNTRUSTED) {
     login_display_->ShowError(IDS_LOGIN_ERROR_OWNER_KEY_LOST, 1,
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     display_email_.clear();
     return;
   } else if (status != CrosSettingsProvider::TRUSTED) {
     // Value of AllowNewUser setting is still not verified.
     // Another attempt will be invoked after verification completion.
+    StartPublicSessionAutoLoginTimer();

[bartfab (slow), 2013/02/25 16:51:23]

Notice that we end up here if the policy subsystem is not quite ready yet and we
need to wait for a callback before continuing with the login. In such a case,
the login attempt is still pending and the timer should not be restarted.

[dconnelly, 2013/02/26 18:04:15]

Done.

     return;
   }
 
   bool allow_guest;
   cros_settings_->GetBoolean(kAccountsPrefAllowGuest, &allow_guest);
   if (!allow_guest) {
     // Disallowed. The UI should normally not show the guest pod but if for some
     // reason this has been made available to the user here is the time to tell
     // this nicely.
     login_display_->ShowError(IDS_LOGIN_ERROR_WHITELIST, 1,
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     display_email_.clear();
     return;
   }
 
   // Only one instance of LoginPerformer should exist at a time.
   login_performer_.reset(NULL);
   login_performer_.reset(new LoginPerformer(this));
   is_login_in_progress_ = true;
   login_performer_->LoginOffTheRecord();
   accessibility::MaybeSpeak(
       l10n_util::GetStringUTF8(IDS_CHROMEOS_ACC_LOGIN_SIGNIN_OFFRECORD));
 }
 
 void ExistingUserController::MigrateUserData(const std::string& old_password) {
   // LoginPerformer instance has state of the user so it should exist.
   if (login_performer_.get())
     login_performer_->RecoverEncryptedData(old_password);
 }
 
 void ExistingUserController::LoginAsPublicAccount(
     const std::string& username) {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
   CrosSettingsProvider::TrustedStatus status =
       cros_settings_->PrepareTrustedValues(
           base::Bind(&ExistingUserController::LoginAsPublicAccount,
                      weak_factory_.GetWeakPtr(),
                      username));
   // If device policy is permanently unavailable, logging into public accounts
   // is not possible.
   if (status == CrosSettingsProvider::PERMANENTLY_UNTRUSTED) {
     login_display_->ShowError(IDS_LOGIN_ERROR_OWNER_KEY_LOST, 1,
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
     // Re-enable clicking on other windows.
     login_display_->SetUIEnabled(true);
     return;
   }
 
   // If device policy is not verified yet, this function will be called again
   // when verification finishes.
-  if (status != CrosSettingsProvider::TRUSTED)
+  if (status != CrosSettingsProvider::TRUSTED) {
+    StartPublicSessionAutoLoginTimer();

[bartfab (slow), 2013/02/25 16:51:23]

Notice that we end up here if the policy subsystem is not quite ready yet and we
need to wait for a callback before continuing with the login. In such a case,
the login attempt is still pending and the timer should not be restarted.

[dconnelly, 2013/02/26 18:04:15]

Done.

     return;
+  }
 
   // If there is no public account with the given |username|, logging in is not
   // possible.
   const User* user = UserManager::Get()->FindUser(username);
   if (!user || user->GetType() != User::USER_TYPE_PUBLIC_ACCOUNT) {
     // Re-enable clicking on other windows.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     return;
   }
 
   // Only one instance of LoginPerformer should exist at a time.
   login_performer_.reset(NULL);
   login_performer_.reset(new LoginPerformer(this));
   is_login_in_progress_ = true;
   login_performer_->LoginAsPublicAccount(username);
   accessibility::MaybeSpeak(
       l10n_util::GetStringUTF8(IDS_CHROMEOS_ACC_LOGIN_SIGNIN_PUBLIC_ACCOUNT));
 }
 
+void ExistingUserController::OnSigninScreenReady() {
+  signin_screen_ready_ = true;
+  StartPublicSessionAutoLoginTimer();
+}
+
 void ExistingUserController::OnUserSelected(const std::string& username) {
   login_performer_.reset(NULL);
   num_login_attempts_ = 0;
 }
 
 void ExistingUserController::OnStartEnterpriseEnrollment() {
   DeviceSettingsService::Get()->GetOwnershipStatusAsync(
       base::Bind(&ExistingUserController::OnEnrollmentOwnershipCheckCompleted,
                  weak_factory_.GetWeakPtr()));
 }
@@ skipping 118 matching lines @@
         ShowError(IDS_LOGIN_ERROR_AUTHENTICATING_HOSTED, error);
       } else {
         if (!is_known_user)
           ShowError(IDS_LOGIN_ERROR_AUTHENTICATING_NEW, error);
         else
           ShowError(IDS_LOGIN_ERROR_AUTHENTICATING, error);
       }
     }
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
   }
 
   // Reset user flow to default, so that special flow will not affect next
   // attempt.
   UserManager::Get()->ResetUserFlow(last_login_attempt_username_);
 
   if (login_status_consumer_)
     login_status_consumer_->OnLoginFailure(failure);
 
   // Clear the recorded displayed email so it won't affect any future attempts.
   display_email_.clear();
 }
 
 void ExistingUserController::OnLoginSuccess(
     const std::string& username,
     const std::string& password,
     bool pending_requests,
     bool using_oauth) {
   is_login_in_progress_ = false;
   offline_failed_ = false;
 
+  StopPublicSessionAutoLoginTimer();
+
   bool has_cookies =
       login_performer_->auth_mode() == LoginPerformer::AUTH_MODE_EXTENSION;
 
   // Login performer will be gone so cache this value to use
   // once profile is loaded.
   password_changed_ = login_performer_->password_changed();
 
   // LoginPerformer instance will delete itself once online auth result is OK.
   // In case of failure it'll bring up ScreenLock and ask for
   // correct password/display error message.
@@ skipping 104 matching lines @@
 
   // Reenable clicking on other windows and status area.
   login_display_->SetUIEnabled(true);
 
   if (login_status_consumer_) {
     login_status_consumer_->OnLoginFailure(LoginFailure(
           LoginFailure::WHITELIST_CHECK_FAILED));
   }
 
   display_email_.clear();
+
+  StartPublicSessionAutoLoginTimer();
 }
 
 void ExistingUserController::PolicyLoadFailed() {
   ShowError(IDS_LOGIN_ERROR_OWNER_KEY_LOST, "");
 
   // Reenable clicking on other windows and status area.
   login_display_->SetUIEnabled(true);
 
   display_email_.clear();
+
+  // Policy load failure stops login attempts---restart the timer.

[bartfab (slow), 2013/02/25 16:51:23]

Nit: I am still bothered by these triple dashes and the lack of spaces around
them :).

[dconnelly, 2013/02/26 18:04:15]

Done.  But I'm going to make sure that every email I send you has three dashes
and no spaces around them.

+  StartPublicSessionAutoLoginTimer();
 }
 
 void ExistingUserController::OnOnlineChecked(const std::string& username,
                                              bool success) {
   if (success && last_login_attempt_username_ == username) {
     online_succeeded_for_ = username;
     // Wait for login attempt to end, if it hasn't yet.
     if (offline_failed_ && !is_login_in_progress_)
       ShowGaiaPasswordChanged(username);
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ExistingUserController, private:
 
 void ExistingUserController::ActivateWizard(const std::string& screen_name) {
   DictionaryValue* params = NULL;
   if (chromeos::UserManager::Get()->IsLoggedInAsGuest()) {
     params = new DictionaryValue;
     params->SetString("start_url", guest_mode_url_.spec());
   }
   host_->StartWizard(screen_name, params);
 }
 
+void ExistingUserController::ConfigurePublicSessionAutoLogin() {
+  if (!cros_settings_->GetString(
+          kAccountsPrefDeviceLocalAccountAutoLoginId,
+          &public_session_auto_login_username_) ||
+      public_session_auto_login_username_.empty()) {
+    public_session_auto_login_username_ = "";

[bartfab (slow), 2013/02/25 16:51:23]

You can simplify this to:

if (!cros_settings_->GetString(
        kAccountsPrefDeviceLocalAccountAutoLoginId,
        &public_session_auto_login_username_)) {
  public_session_auto_login_username_ = "";
}

[dconnelly, 2013/02/26 18:04:15]

Done.

+  }
+  if (!cros_settings_->GetInteger(
+          kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+          &public_session_auto_login_delay_)) {
+    public_session_auto_login_delay_ = 0;
+  }
+
+  ash::UserActivityDetector* detector = ash::Shell::HasInstance()
+      ? ash::Shell::GetInstance()->user_activity_detector() : NULL;

[bartfab (slow), 2013/02/25 16:51:23]

I think it is allowed to put the |?| at the start of the line but it is very
uncommon. Better put it at the end of the previous line.

[dconnelly, 2013/02/26 18:04:15]

Done.

+  if (!public_session_auto_login_username_.empty()) {
+    StartPublicSessionAutoLoginTimer();
+    if (detector && !detector->HasObserver(this))
+      detector->AddObserver(this);
+  } else {
+    if (detector)
+      detector->RemoveObserver(this);
+    StopPublicSessionAutoLoginTimer();
+  }
+}
+
+void ExistingUserController::OnUserActivity() {
+  if (auto_login_timer_.IsRunning()) {

[bartfab (slow), 2013/02/25 16:51:23]

It is pretty obvious what this function is doing but I think that a comment
would still be useful here: Document the fact that this restarts the timer but
only if it is currently running.

[dconnelly, 2013/02/26 18:04:15]

Done.

+    StopPublicSessionAutoLoginTimer();
+    StartPublicSessionAutoLoginTimer();
+  }
+}
+
+void ExistingUserController::OnPublicSessionAutoLoginTimerFire() {
+  DCHECK(signin_screen_ready_ &&
+         !is_login_in_progress_ &&
+         !public_session_auto_login_username_.empty());
+  LoginAsPublicAccount(public_session_auto_login_username_);
+}
+
+void ExistingUserController::StopPublicSessionAutoLoginTimer() {
+  auto_login_timer_.Stop();
+}
+
+void ExistingUserController::StartPublicSessionAutoLoginTimer() {
+  if (!signin_screen_ready_ ||
+      public_session_auto_login_username_.empty() ||
+      is_login_in_progress_) {

[bartfab (slow), 2013/02/25 16:51:23]

Nit: The conditions in lines 956-958 and 967-969 are the exact logical inverses
of each other but they are arranged in different order. Could you arrange them
in the same order for consistency?

[dconnelly, 2013/02/26 18:04:15]

Done.

+    return;
+  }
+
+  // Start the auto-login timer.
+  auto_login_timer_.Start(
+      FROM_HERE,
+      base::TimeDelta::FromMilliseconds(
+          public_session_auto_login_delay_),
+      base::Bind(
+          &ExistingUserController::OnPublicSessionAutoLoginTimerFire,
+          weak_factory_.GetWeakPtr()));
+}
+
 gfx::NativeWindow ExistingUserController::GetNativeWindow() const {
   return host_->GetNativeWindow();
 }
 
 void ExistingUserController::InitializeStartUrls() const {
   std::vector<std::string> start_urls;
 
   PrefService* prefs = g_browser_process->local_state();
   const base::ListValue *urls;
   bool show_getstarted_guide = false;
@@ skipping 127 matching lines @@
   // changed.
   UserManager::Get()->SaveUserOAuthStatus(
       username,
       User::OAUTH2_TOKEN_STATUS_INVALID);
 
   login_display_->SetUIEnabled(true);
   login_display_->ShowGaiaPasswordChanged(username);
 }
 
 }  // namespace chromeos