Be more picky in triggering enrollment recovery.

chrome/browser/chromeos/policy/device_cloud_policy_store_chromeos.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/policy/device_cloud_policy_store_chromeos.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/sequenced_task_runner.h"
 #include "chrome/browser/chromeos/login/startup_utils.h"
 #include "chrome/browser/chromeos/policy/device_policy_decoder_chromeos.h"
 #include "chrome/browser/chromeos/policy/enterprise_install_attributes.h"
 #include "chrome/browser/chromeos/policy/proto/chrome_device_policy.pb.h"
 #include "chrome/browser/chromeos/settings/owner_key_util.h"
 #include "policy/proto/device_management_backend.pb.h"
 
 namespace em = enterprise_management;
 
 namespace policy {
 
 DeviceCloudPolicyStoreChromeOS::DeviceCloudPolicyStoreChromeOS(
     chromeos::DeviceSettingsService* device_settings_service,
     EnterpriseInstallAttributes* install_attributes,
     scoped_refptr<base::SequencedTaskRunner> background_task_runner)
     : device_settings_service_(device_settings_service),
       install_attributes_(install_attributes),
       background_task_runner_(background_task_runner),
-      first_update_(true),
+      enrollment_validation_done_(false),
       weak_factory_(this) {
   device_settings_service_->AddObserver(this);
 }
 
 DeviceCloudPolicyStoreChromeOS::~DeviceCloudPolicyStoreChromeOS() {
   device_settings_service_->RemoveObserver(this);
 }
 
 void DeviceCloudPolicyStoreChromeOS::Store(
     const em::PolicyFetchResponse& policy) {
@@ skipping 91 matching lines @@
   UpdateFromService();
 }
 
 void DeviceCloudPolicyStoreChromeOS::UpdateFromService() {
   if (!install_attributes_->IsEnterpriseDevice()) {
     status_ = STATUS_BAD_STATE;
     NotifyStoreError();
     return;
   }
 
-  // Fill UMA histogram once per session.  Skip temp validation error because it
-  // is not a definitive result (policy load will be retried).
+  // Once per session, validate internal consistency of enrollment state (DM
+  // token must be present on enrolled devices) and in case of failure set flag
+  // to indicate that recovery is required.  Since UpdateFromService() is called
+  // upon completion of any kind of SessionManagerOperation, validation is only
+  // performed for the first time a status codes is encountered that may
+  // correspond to completing a read request.
   const chromeos::DeviceSettingsService::Status status =
       device_settings_service_->status();
-  if (first_update_ &&
-      status != chromeos::DeviceSettingsService::STORE_TEMP_VALIDATION_ERROR) {
-    first_update_ = false;
+  if ((status == chromeos::DeviceSettingsService::STORE_SUCCESS ||
+       status == chromeos::DeviceSettingsService::STORE_KEY_UNAVAILABLE ||
+       status == chromeos::DeviceSettingsService::STORE_NO_POLICY ||
+       status == chromeos::DeviceSettingsService::STORE_INVALID_POLICY ||
+       status == chromeos::DeviceSettingsService::STORE_VALIDATION_ERROR)

[pastarmovj, 2014/07/18 10:14:54]

I would suggest to change this to a switch to guarantee that the code will be
adjusted if the DSS:Status defintion should change in the future.

[Thiemo Nagel, 2014/07/18 11:54:04]

Done.

+      && !enrollment_validation_done_) {
+    enrollment_validation_done_ = true;
     const bool has_dm_token =
         status == chromeos::DeviceSettingsService::STORE_SUCCESS &&
         device_settings_service_->policy_data() &&
         device_settings_service_->policy_data()->has_request_token();
 
     // At the time LoginDisplayHostImpl decides whether enrollment flow is to be
     // started, policy hasn't been read yet, so LoginDisplayHostImpl is not in a
     // position to decide whether recovery is required.  To work around this,
     // upon policy load on machines requiring recovery, a flag is stored in
     // prefs which is accessed by LoginDisplayHostImpl early during (next) boot.
     if (!has_dm_token) {
-      LOG(ERROR) << "Policy read on enrolled device yields no DM token! "
+      LOG(ERROR) << "Device policy read on enrolled device yields no DM token! "
                  << "Status: " << status << ".";
       chromeos::StartupUtils::MarkEnrollmentRecoveryRequired();
     }
     UMA_HISTOGRAM_BOOLEAN("Enterprise.EnrolledPolicyHasDMToken", has_dm_token);
   }
 
   switch (device_settings_service_->status()) {
     case chromeos::DeviceSettingsService::STORE_SUCCESS: {
       status_ = STATUS_OK;
       policy_.reset(new em::PolicyData());
@@ skipping 22 matching lines @@
     case chromeos::DeviceSettingsService::STORE_VALIDATION_ERROR:
     case chromeos::DeviceSettingsService::STORE_TEMP_VALIDATION_ERROR:
       status_ = STATUS_LOAD_ERROR;
       break;
   }
 
   NotifyStoreError();
 }
 
 }  // namespace policy