Add CloudPolicyService

chrome/browser/policy/cloud_policy_store.h

+// 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.
+
+#ifndef CHROME_BROWSER_POLICY_CLOUD_POLICY_STORE_H_
+#define CHROME_BROWSER_POLICY_CLOUD_POLICY_STORE_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
+#include "chrome/browser/policy/policy_map.h"
+#include "chrome/browser/policy/proto/device_management_backend.pb.h"
+
+namespace policy {
+
+// Defines the low-level interface used by the cloud policy code to:
+//   1. Validate policy blobs that should be applied locally
+//   2. Persist policy blobs
+//   3. Decode policy blobs to PolicyMap representation
+class CloudPolicyStore {
+ public:
+  // Status codes.
+  enum Status {
+    // Everything is in good order.
+    STATUS_OK,
+    // Loading policy from the underlying data store failed.
+    STATUS_PERSIST_LOAD_ERROR,
+    // Failed to store policy to the data store.
+    STATUS_PERSIST_STORE_ERROR,
+    // Failed to parse the policy read from the data store.
+    STATUS_PERSIST_PARSE_ERROR,
+    // Failed to serialize policy for storage.
+    STATUS_PERSIST_SERIALIZE_ERROR,
+    // Validation failure: Bad signature.
+    STATUS_VALIDATION_BAD_SIGNATURE,
+    // Validation failure: Policy blob contains error code.
+    STATUS_VALIDATION_ERROR_CODE_PRESENT,
+    // Validation failure: Policy payload failed to decode.
+    STATUS_VALIDATION_PAYLOAD_PARSE_ERROR,
+    // Validation failure: Unexpected policy type.
+    STATUS_VALIDATION_POLICY_TYPE,
+    // Validation failure: Time stamp.

[Joao da Silva, 2012/05/22 22:01:44]

Timestamp in the future?

[Mattias Nissler (ping if slow), 2012/05/24 10:12:25]

Unless we make the check also reject policy that is too old... Or we might want
to introduce a new error code. For now, I've updated the comment.

+    STATUS_VALIDATION_TIMESTAMP,
+    // Validation failure: Token doesn't match.
+    STATUS_VALIDATION_TOKEN,
+    // Validation failure: Username doesn't match.
+    STATUS_VALIDATION_USERNAME,
+    // Policy protobuf parse error.
+    STATUS_VALIDATION_POLICY_PARSE_ERROR,
+  };
+
+  // Callbacks for policy store events. Most importantly, policy updates.
+  class Observer {
+   public:
+    virtual ~Observer();
+
+    // Called on changes to store->policy() and/or store->policy_map().
+    virtual void OnStoreLoaded(CloudPolicyStore* store) = 0;
+
+    // Called upon encountering errors.
+    virtual void OnStoreError(CloudPolicyStore* store) = 0;
+  };
+
+  CloudPolicyStore();
+  virtual ~CloudPolicyStore();
+
+  // Indicates whether the store has been fully initialized. This is
+  // accomplished by calling Load() after startup.
+  bool is_initialized() const { return is_initialized_; }
+
+  const PolicyMap& policy_map() const { return policy_map_; }
+  bool has_policy() const {
+    return policy_.get() != NULL;
+  }
+  const enterprise_management::PolicyData* policy() const {
+    return policy_.get();
+  }
+  bool is_managed() const {
+    return policy_.get() &&
+           policy_->state() == enterprise_management::PolicyData::ACTIVE;
+  }
+  Status status() const { return status_; }
+
+  // Store a new policy blob. Pending store operations will be canceled. The
+  // store operation may proceed asynchronously and observers are notified once
+  // the operation finishes. If successful, OnStoreLoaded() will be invoked on
+  // the observers and the updated policy can be read through policy(). Errors
+  // generate OnStoreError() notifications.
+  virtual void Store(
+      const enterprise_management::PolicyFetchResponse& policy) = 0;

[Joao da Silva, 2012/05/22 22:01:44]

I'm assuming |policy| only has to be valid during this call; otherwise the
lifetime expectation should be documented.

[Mattias Nissler (ping if slow), 2012/05/24 10:12:25]

Yes, it's meant to be copied to whatever internal representation the
implementation wants to use.

+
+  // Load the current policy blob from persistent storage. This may trigger
+  // asynchronous operations. Upon success, OnStoreLoaded() will be called on
+  // the registered observers. Otherwise, OnStoreError() reports the reason for
+  // failure.
+  virtual void Load() = 0;
+
+  // Registers an observer to be notified when policy changes.
+  void AddObserver(Observer* observer);
+
+  // Removes the specified observer.
+  void RemoveObserver(Observer* observer);
+
+ protected:
+  // Decoded version of the currently effective policy.
+  PolicyMap policy_map_;
+
+  // Currently effective policy.
+  scoped_ptr<enterprise_management::PolicyData> policy_;
+
+  // Latest status code.
+  Status status_;
+
+  // Invokes the corresponding callback on all registered observers.
+  void NotifyStoreLoaded();
+  void NotifyStoreError();

[Joao da Silva, 2012/05/22 22:01:44]

Nit: methods before data fields.

[Mattias Nissler (ping if slow), 2012/05/24 10:12:25]

Done.

+
+ private:
+  // Whether the store has completed asynchronous initialization, which is
+  // triggered by calling Load().
+  bool is_initialized_;
+
+  ObserverList<Observer, true> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(CloudPolicyStore);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_CLOUD_POLICY_STORE_H_