Change PolicyLoaderWin to load PReg files if possible.

chrome/browser/policy/policy_loader_win.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_POLICY_LOADER_WIN_H_
 #define CHROME_BROWSER_POLICY_POLICY_LOADER_WIN_H_
 
+#include <userenv.h>
+#include <windows.h>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/values.h"
 #include "base/win/object_watcher.h"
 #include "chrome/browser/policy/async_policy_loader.h"
+#include "chrome/browser/policy/policy_types.h"
+
+namespace base {
+class FilePath;
+}
 
 namespace policy {
 
+class AppliedGPOListProvider;
+class PolicyMap;
 struct PolicyDefinitionList;
-class PolicyMap;
+
+// Interface for mocking out GPO enumeration in tests.
+class AppliedGPOListProvider {
+ public:
+  virtual ~AppliedGPOListProvider() {}
+  virtual DWORD GetAppliedGPOList(DWORD flags,
+                                  LPCTSTR machine_name,
+                                  PSID sid_user,
+                                  GUID* extension_guid,
+                                  PGROUP_POLICY_OBJECT* gpo_list) = 0;
+  virtual BOOL FreeGPOList(PGROUP_POLICY_OBJECT gpo_list) = 0;
+};
 
 // Loads policies from the Windows registry, and watches for Group Policy
 // notifications to trigger reloads.
 class PolicyLoaderWin : public AsyncPolicyLoader,
                         public base::win::ObjectWatcher::Delegate {
  public:
-  explicit PolicyLoaderWin(const PolicyDefinitionList* policy_list);
+  explicit PolicyLoaderWin(const PolicyDefinitionList* policy_list,
+                           const string16& chrome_policy_key,
+                           AppliedGPOListProvider* gpo_provider);
   virtual ~PolicyLoaderWin();
 
+  // Creates a policy loader that uses the Win API to access GPO.
+  static scoped_ptr<PolicyLoaderWin> Create(
+      const PolicyDefinitionList* policy_list);
+
   // AsyncPolicyLoader implementation.
   virtual void InitOnFile() OVERRIDE;
   virtual scoped_ptr<PolicyBundle> Load() OVERRIDE;
 
  private:
-  void LoadChromePolicy(PolicyMap* chrome_policies);
-  void Load3rdPartyPolicies(PolicyBundle* bundle);
+  // Builds the Chrome policy schema in |chrome_policy_schema_|.
+  void BuildChromePolicySchema();
+
+  // Reads Chrome Policy from a PReg file at the given path and stores the
+  // result in |policy|.
+  bool ReadPRegFile(const base::FilePath& preg_file,
+                    base::DictionaryValue* policy);
+
+  // Loads and parses GPO policy in |policy_object_list| for scope |scope|. If
+  // successful, stores the result in |policy| and returns true. Returns false
+  // on failure reading the policy, indicating that policy loading should fall
+  // back to reading the registry.
+  bool LoadGPOPolicy(PolicyScope scope,
+                     PGROUP_POLICY_OBJECT policy_object_list,
+                     base::DictionaryValue* policy);
+
+  // Queries Windows for applied group policy and writes the result to |policy|.
+  // This is the preferred way to obtain GPO data, there are reports of abuse
+  // of the registry GPO keys by 3rd-party software.
+  bool ReadPolicyFromGPO(PolicyScope scope, base::DictionaryValue* policy);

[Joao da Silva, 2013/04/10 12:32:12]

Seems a bit arbitrary that methods are used to read from GPO, and functions in
the anonymous namespace are used to read from the registry.

[Mattias Nissler (ping if slow), 2013/04/10 13:20:25]

It is not entirely arbitrary, the GPO functions needs the registry key name (and
threading that through is tedious), while ReadRegistry() is truly generic.

+
+  // Parses Chrome policy from |gpo_dict| for the given |scope| and |level| and
+  // merges it into |chrome_policy_map|.
+  void LoadChromePolicy(const base::DictionaryValue* gpo_dict,
+                        PolicyLevel level,
+                        PolicyScope scope,
+                        PolicyMap* chrome_policy_map);
+
+  // Loads 3rd-party policy from |gpo_dict| and merges it into |bundle|.
+  void Load3rdPartyPolicy(const base::DictionaryValue* gpo_dict,
+                          PolicyScope scope,
+                          PolicyBundle* bundle);
 
   // Installs the watchers for the Group Policy update events.
   void SetupWatches();
 
   // ObjectWatcher::Delegate overrides:
   virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
 
   bool is_initialized_;
   const PolicyDefinitionList* policy_list_;
+  const string16 chrome_policy_key_;
+  class AppliedGPOListProvider* gpo_provider_;
+  base::DictionaryValue chrome_policy_schema_;
 
   base::WaitableEvent user_policy_changed_event_;
   base::WaitableEvent machine_policy_changed_event_;
   base::win::ObjectWatcher user_policy_watcher_;
   base::win::ObjectWatcher machine_policy_watcher_;
   bool user_policy_watcher_failed_;
   bool machine_policy_watcher_failed_;
 
   DISALLOW_COPY_AND_ASSIGN(PolicyLoaderWin);
 };
 
-// Constants shared with tests.
-namespace registry_constants {
-  // Path separator for registry keys.
-  extern const wchar_t kPathSep[];
-  // Registry key within Chrome's key that contains 3rd party policy.
-  extern const wchar_t kThirdParty[];
-  // Registry key within an extension's namespace that contains mandatory
-  // policy.
-  extern const wchar_t kMandatory[];
-  // Registry key within an extension's namespace that contains recommended
-  // policy.
-  extern const wchar_t kRecommended[];
-  // Registry key within an extension's namespace that contains the policy
-  // schema.
-  extern const wchar_t kSchema[];
-}  // namespace registry_constants
-
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_POLICY_LOADER_WIN_H_