New policy protobuf protocol.

chrome/browser/policy/cloud_policy_cache.h

Index: chrome/browser/policy/cloud_policy_cache.h
diff --git a/chrome/browser/policy/cloud_policy_cache.h b/chrome/browser/policy/cloud_policy_cache.h
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+// Copyright (c) 2011 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_CACHE_H_
+#define CHROME_BROWSER_POLICY_CLOUD_POLICY_CACHE_H_
+
+#include <map>

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

do you need this?

[Jakob Kummerow, 2011/02/08 16:15:43]

No, I don't. Done.

+#include <string>
+
+#include "base/file_path.h"
+#include "base/gtest_prod_util.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "base/time.h"
+#include "chrome/browser/policy/configuration_policy_provider.h"
+#include "chrome/browser/policy/proto/device_management_backend.pb.h"
+#include "policy/configuration_policy_type.h"
+
+class DictionaryValue;
+class ListValue;
+class Value;
+
+using google::protobuf::RepeatedPtrField;
+
+namespace policy {
+
+namespace em = enterprise_management;
+
+// Decodes a CloudPolicySettings object into two maps with mandatory and
+// recommended settings, respectively. The implementation is generated code.

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

maybe also add the file name to look at?

[Jakob Kummerow, 2011/02/08 16:15:43]

Done.

+void DecodePolicy(const em::CloudPolicySettings& policy,
+                  ConfigurationPolicyProvider::PolicyMapType* mandatory,
+                  ConfigurationPolicyProvider::PolicyMapType* recommended);
+
+// Keeps the authoritative copy of cloud policy information as read from the
+// persistence file or determined by the policy backend. The cache doesn't talk
+// to the service directly, but receives updated policy information through
+// SetPolicy() calls, which is then persisted and decoded into the internal
+// Value representation chrome uses.
+class CloudPolicyCache {
+ public:
+  explicit CloudPolicyCache(const FilePath& backing_file_path);
+  ~CloudPolicyCache();
+
+  // Loads policy information from the backing file. Non-existing or erroneous
+  // cache files are ignored.
+  void LoadPolicyFromFile();
+
+  // Resets the policy information. Returns true if the new policy is different
+  // from the previously stored policy.
+  bool SetPolicy(const em::CloudPolicyResponse& policy);
+  bool SetPolicy(const em::DevicePolicyResponse& policy);

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

we generally discourage overloads (see the style guide). It might even sense to
rename the DevicePolicyResponse variant to SetLegacyPolicy() or something in
order to indicate this is not the code path you should add new features to.

[Jakob Kummerow, 2011/02/08 16:15:43]

Done.

+
+  // Gets the policy information. Ownership of the return value is transferred
+  // to the caller.
+  DictionaryValue* GetDevicePolicy();

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

Why do we still need this?

[Jakob Kummerow, 2011/02/08 16:15:43]

Because for the time being, DMServer only gives us old-style device policy, and
we need to access that somehow after having cached it :-)

+  ConfigurationPolicyProvider::PolicyMapType* GetMandatoryPolicy();
+  ConfigurationPolicyProvider::PolicyMapType* GetRecommendedPolicy();
+
+  void SetUnmanaged();
+  bool is_unmanaged() const {
+    return is_unmanaged_;
+  }
+
+  // Returns the time as which the policy was last fetched.
+  base::Time last_policy_refresh_time() const {
+    return last_policy_refresh_time_;
+  }
+
+  // Returns true if this cache holds (old-style) device policy that should be
+  // given preference over (new-style) mandatory/recommended policy.
+  bool has_device_policy() const {

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

Why would we need this? Can't the provider just ask for both in sequence and
take the first one that is non-null?

[Jakob Kummerow, 2011/02/08 16:15:43]

Currently no policy ever returns null; it'll just be an empty list if no policy
is set. I guess we could change it, but it wouldn't be easier than maintaining
this flag.

+    return has_device_policy_;
+  }
+
+ private:
+  friend class CloudPolicyCacheTest;
+  friend class DeviceManagementPolicyCacheDecodeTest;
+
+  // Decodes a CloudPolicyResponse into two (ConfigurationPolicyType -> Value*)
+  // maps and a timestamp. Also performs verification, returns NULL if any
+  // check fails.
+  static bool DecodePolicyResponse(
+      const em::CloudPolicyResponse& policy_response,
+      ConfigurationPolicyProvider::PolicyMapType* mandatory,
+      ConfigurationPolicyProvider::PolicyMapType* recommended,
+      base::Time* timestamp);
+
+  // Returns true if |certificate_chain| is trusted and a |signature| created
+  // from it matches |data|.
+  static bool VerifySignature(
+      const std::string& signature,
+      const std::string& data,
+      const RepeatedPtrField<std::string>& certificate_chain);
+
+  // Returns true if |a| equals |b|.
+  static bool Equals(const ConfigurationPolicyProvider::PolicyMapType* a,
+                     const ConfigurationPolicyProvider::PolicyMapType* b);

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

can you use std::equal from <algorithm> instead?

[Jakob Kummerow, 2011/02/08 16:15:43]

No, because I need Value::Equals(). |operator=| isn't defined for Values.

+
+  // Returns a copy of the |original| PolicyMapType. Caller takes ownership.
+  ConfigurationPolicyProvider::PolicyMapType* CopyPolicyMap(
+      const ConfigurationPolicyProvider::PolicyMapType* original);

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

also looks like std::copy could help here.

[Jakob Kummerow, 2011/02/08 16:15:43]

No, because Value::DeepCopy() was needed. However, I was able to avoid copying
policy maps altogether.

+
+  // Decodes an int64 value. Checks whether the passed value fits the numeric
+  // limits of the value representation. Returns a value (ownership is
+  // transferred to the caller) on success, NULL on failure.
+  static Value* DecodeIntegerValue(google::protobuf::int64 value);
+
+  // Decode a GenericValue message to the Value representation used internally.
+  // Returns NULL if |value| is invalid (i.e. contains no actual value).
+  static Value* DecodeValue(const em::GenericValue& value);
+
+  // Decodes a policy message and returns it in Value representation. Ownership
+  // of the returned dictionary is transferred to the caller.
+  static DictionaryValue* DecodeDevicePolicy(
+      const em::DevicePolicyResponse& response);
+
+  // The file in which we store a cached version of the policy information.
+  const FilePath backing_file_path_;
+
+  // Protects both |mandatory_policy_| and |recommended_policy_| as well as
+  // |device_policy_|.
+  base::Lock lock_;

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

do we still need locking here?

[Jakob Kummerow, 2011/02/08 16:15:43]

I guess we don't (would need to take a closer look to give a definitive answer),
but it's a moot point since your own CL restructures all of this and removes the
lock anyway.

+
+  // Policy key-value information.
+  scoped_ptr<ConfigurationPolicyProvider::PolicyMapType> mandatory_policy_;
+  scoped_ptr<ConfigurationPolicyProvider::PolicyMapType> recommended_policy_;
+  scoped_ptr<DictionaryValue> device_policy_;

[Mattias Nissler (ping if slow), 2011/02/03 16:23:41]

why is this still needed?

[Jakob Kummerow, 2011/02/08 16:15:43]

To store old-style policy until support for that is removed.
(In theory, it would be possible to put that into mandatory_policy_, but due to
the different mapping type that approach would require a throw-away
implementation involving more generated code, which I don't think would be an
efficient thing to do in terms of engineering effort.)

+
+  // Tracks whether the store received a SetPolicy() call, which overrides any
+  // information loaded from the file.
+  bool fresh_policy_;
+
+  bool is_unmanaged_;
+
+  // Tracks whether the cache currently stores |device_policy_| that should be
+  // given preference over |mandatory_policy_| and |recommended_policy_|.
+  bool has_device_policy_;
+
+  // The time at which the policy was last refreshed.
+  base::Time last_policy_refresh_time_;
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_CLOUD_POLICY_CACHE_H_