Implement a policy to autologin a public account.

chrome/browser/chromeos/login/existing_user_controller.cc

Index: chrome/browser/chromeos/login/existing_user_controller.cc
diff --git a/chrome/browser/chromeos/login/existing_user_controller.cc b/chrome/browser/chromeos/login/existing_user_controller.cc
index 3b6632a38632b468b8ba668e69fe9d1ae19949f0..0ce479639bd1078ec2c0e73e7241510ec3888d6f 100644
--- a/chrome/browser/chromeos/login/existing_user_controller.cc
+++ b/chrome/browser/chromeos/login/existing_user_controller.cc
@@ -6,6 +6,7 @@
 
 #include <vector>
 
+#include "ash/wm/user_activity_detector.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
@@ -143,7 +144,8 @@ ExistingUserController::ExistingUserController(LoginDisplayHost* host)
       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;
 
@@ -163,11 +165,18 @@ ExistingUserController::ExistingUserController(LoginDisplayHost* host)
   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();
@@ -228,6 +237,13 @@ void ExistingUserController::Observe(
     registrar_.RemoveAll();
     return;
   }
+  if (type == chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED) {
+    std::string setting = *content::Details<const std::string>(details).ptr();
+    if (setting == kAccountsPrefDeviceLocalAccountAutoLoginId ||
+        setting == kAccountsPrefDeviceLocalAccountAutoLoginDelay) {
+      ConfigurePublicSessionAutoLogin();
+    }
+  }
   if (type == chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED ||
       type == chrome::NOTIFICATION_USER_LIST_CHANGED) {
     if (host_ != NULL) {
@@ -277,6 +293,12 @@ ExistingUserController::~ExistingUserController() {
   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 (current_controller_ == this) {
     current_controller_ = NULL;
@@ -331,6 +353,9 @@ void ExistingUserController::CompleteLogin(const std::string& username,
     return;
   }
 
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable UI while loading user profile.
   login_display_->SetUIEnabled(false);
 
@@ -387,6 +412,10 @@ 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);
 
@@ -434,6 +463,9 @@ void ExistingUserController::PerformLogin(
 }
 
 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
@@ -449,6 +481,9 @@ void ExistingUserController::LoginAsRetailModeUser() {
 }
 
 void ExistingUserController::LoginAsGuest() {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
@@ -462,11 +497,13 @@ void ExistingUserController::LoginAsGuest() {
                               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();
     return;
   }
 
@@ -480,6 +517,7 @@ void ExistingUserController::LoginAsGuest() {
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     display_email_.clear();
     return;
   }
@@ -499,6 +537,9 @@ void ExistingUserController::MigrateUserData(const std::string& 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);
 
@@ -519,8 +560,10 @@ void ExistingUserController::LoginAsPublicAccount(
 
   // 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();
     return;
+  }
 
   // If there is no public account with the given |username|, logging in is not
   // possible.
@@ -528,6 +571,7 @@ void ExistingUserController::LoginAsPublicAccount(
   if (!user || user->GetType() != User::USER_TYPE_PUBLIC_ACCOUNT) {
     // Re-enable clicking on other windows.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     return;
   }
 
@@ -540,6 +584,11 @@ void ExistingUserController::LoginAsPublicAccount(
       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;
@@ -680,6 +729,8 @@ void ExistingUserController::OnLoginFailure(const LoginFailure& failure) {
 
   // Clear the recorded displayed email so it won't affect any future attempts.
   display_email_.clear();
+
+  StartPublicSessionAutoLoginTimer();
 }
 
 void ExistingUserController::OnLoginSuccess(
@@ -834,6 +885,9 @@ void ExistingUserController::PolicyLoadFailed() {
   login_display_->SetUIEnabled(true);
 
   display_email_.clear();
+
+  // Policy load failure stops login attempts---restart the timer.
+  StartPublicSessionAutoLoginTimer();
 }
 
 void ExistingUserController::OnOnlineChecked(const std::string& username,
@@ -875,6 +929,52 @@ void ExistingUserController::ActivateWizard(const std::string& screen_name) {
   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_ = "";
+  }
+  if (!cros_settings_->GetInteger(
+          kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+          &public_session_auto_login_delay_)) {
+    public_session_auto_login_delay_ = 0;
+  }
+
+  if (!public_session_auto_login_username_.empty()) {
+    if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
+      ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);

[Nikita (slow), 2013/02/11 17:30:29]

Remove observer in dtor?

[bartfab (slow), 2013/02/11 17:37:31]

The observer could be unconditionally added and removed. No harm in having it
always there, except a small amount of overhead.

[Nikita (slow), 2013/02/11 17:51:31]

Ok then.

[dconnelly, 2013/02/21 10:42:21]

Done.

+    StartPublicSessionAutoLoginTimer();
+  } else {
+    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);

[Nikita (slow), 2013/02/11 17:30:29]

On a normal boot path (i.e. no public accounts configured) you'll be removing
observer that you hadn't in fact added.

[bartfab (slow), 2013/02/11 17:37:31]

It's actually benign to remove an observer that does not exists.
ObserverListBase just ignores it.

[Nikita (slow), 2013/02/11 17:51:31]

I thought that previously it had a such check so it was either removed or I'm
confusing that with a different check.

[dconnelly, 2013/02/21 10:42:21]

You're not confused--there was a check before.  I was replicating some other
code that performs a similar task, but then I looked at the header for
ObserverList and found what Bartosz just said, so I removed the check.

+    StopPublicSessionAutoLoginTimer();
+  }
+}
+
+void ExistingUserController::OnUserActivity() {
+  if (auto_login_timer_.IsRunning()) {
+    StopPublicSessionAutoLoginTimer();
+    StartPublicSessionAutoLoginTimer();

[Nikita (slow), 2013/02/11 17:30:29]

What's the point of restarting timer?

[bartfab (slow), 2013/02/11 17:37:31]

The idea is that the timer performs an auto-login X minutes after the last user
activity on the login screen.

* If the device boots and nobody touches it -> auto login after X minutes.
* If the device boots and someone logs in within X minutes -> no auto login.
* If the device boots, someone tries to log in but changes their mind / fails ->
auto-login X minutes after the last user activity.

This requires that the timer be restarted whenever there is user activity or
when a login fails.

[Nikita (slow), 2013/02/11 17:57:17]

Take into account that device will power off after a period of inactivity on
login screen.

I see that user_activity_detector() observer is not removed when login is
successful. Consider the situation that user has started (new) session and has
some UI that is rendered by the login screen. So ExistingUserController instance
does still exist but auto-login timer doesn't make sense at this point.

+  }
+}
+
+void ExistingUserController::StopPublicSessionAutoLoginTimer() {
+  auto_login_timer_.Stop();
+}
+
+void ExistingUserController::StartPublicSessionAutoLoginTimer() {
+  if (!signin_screen_ready_ || public_session_auto_login_username_.empty())
+    return;
+  auto_login_timer_.Start(FROM_HERE,
+                          base::TimeDelta::FromMilliseconds(
+                              public_session_auto_login_delay_),
+                          base::Bind(
+                              &ExistingUserController::LoginAsPublicAccount,
+                              weak_factory_.GetWeakPtr(),
+                              public_session_auto_login_username_));
+}
+
 gfx::NativeWindow ExistingUserController::GetNativeWindow() const {
   return host_->GetNativeWindow();
 }