Refactor the various ways to control what users can do to extensions.

chrome/browser/extensions/extension_service.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/extensions/extension_service.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/stl_util.h"
-#include "base/string16.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "chrome/browser/accessibility/accessibility_extension_api.h"
 #include "chrome/browser/bookmarks/bookmark_extension_api.h"
@@ skipping 67 matching lines @@
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/pepper_plugin_info.h"
 #include "googleurl/src/gurl.h"
+#include "grit/generated_resources.h"
 #include "net/base/registry_controlled_domain.h"
 #include "sync/api/sync_change.h"
 #include "sync/api/sync_error_factory.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "webkit/database/database_tracker.h"
 #include "webkit/database/database_util.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "chrome/browser/chromeos/extensions/bluetooth_event_router.h"
 #include "chrome/browser/chromeos/extensions/file_browser_event_router.h"
 #include "chrome/browser/chromeos/extensions/input_method_event_router.h"
 #include "chrome/browser/chromeos/extensions/media_player_event_router.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
@@ skipping 176 matching lines @@
 
   // We can't call UninstallExtension with an invalid extension ID.
   if (!extension) {
     LOG(WARNING) << "Attempted uninstallation of non-existent extension with "
                  << "id: " << extension_id;
     return false;
   }
 
   // The following call to UninstallExtension will not allow an uninstall of a
   // policy-controlled extension.
-  std::string error;
+  string16 error;
   if (!extensions_service->UninstallExtension(extension_id, false, &error)) {
     LOG(WARNING) << "Cannot uninstall extension with id " << extension_id
                  << ": " << error;
     return false;
   }
 
   return true;
 }
 
 ExtensionService::ExtensionService(Profile* profile,
@@ skipping 362 matching lines @@
     // We should always be able to remember the extension's path. If it's not in
     // the map, someone failed to update |unloaded_extension_paths_|.
     CHECK(!path.empty());
     extensions::UnpackedInstaller::Create(this)->Load(path);
   }
 }
 
 bool ExtensionService::UninstallExtension(
     std::string extension_id,
     bool external_uninstall,
-    std::string* error) {
+    string16* error) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   scoped_refptr<const Extension> extension(GetInstalledExtension(extension_id));
 
   // Callers should not send us nonexistent extensions.
   CHECK(extension);
 
   // Policy change which triggers an uninstall will always set
   // |external_uninstall| to true so this is the only way to uninstall
   // managed extensions.
-  if (!Extension::UserMayDisable(extension->location()) &&
-      !external_uninstall) {
+  if (!external_uninstall &&
+      !system_->management_policy()->UserMayModifyStatus(
+        extension.get(), error)) {
     content::NotificationService::current()->Notify(
         chrome::NOTIFICATION_EXTENSION_UNINSTALL_NOT_ALLOWED,
         content::Source<Profile>(profile_),
         content::Details<const Extension>(extension));
-    if (error != NULL) {
-      *error = errors::kCannotUninstallManagedExtension;
-    }
     return false;
   }
 
   // Extract the data we need for sync now, but don't actually sync until we've
   // completed the uninstallation.
   SyncChange sync_change;
   if (app_sync_bundle_.HandlesApp(*extension)) {
     sync_change = app_sync_bundle_.CreateSyncChangeToDelete(extension);
   } else if (extension_sync_bundle_.HandlesExtension(*extension)) {
     sync_change = extension_sync_bundle_.CreateSyncChangeToDelete(extension);
@@ skipping 90 matching lines @@
   // enabled unless otherwise noted.
   return !extension_prefs_->IsExtensionDisabled(extension_id) &&
       !extension_prefs_->IsExternalExtensionUninstalled(extension_id);
 }
 
 bool ExtensionService::IsExternalExtensionUninstalled(
     const std::string& extension_id) const {
   return extension_prefs_->IsExternalExtensionUninstalled(extension_id);
 }
 
+std::string ExtensionService::PolicyProviderName() const {
+  return "admin policy forcelist, via the ExtensionService";
+}
+
+bool ExtensionService::UserMayModifyStatus(const Extension* extension,
+                                           string16* error) const {
+  return ManagementPolicyImpl(extension, error, true);
+}
+
+bool ExtensionService::MustRemainEnabled(const Extension* extension,
+                                         string16* error) const {
+  return ManagementPolicyImpl(extension, error, false);
+}
+
+bool ExtensionService::ManagementPolicyImpl(const Extension* extension,
+    string16* error, bool modifiable_value) const {
+  // An extension that is required (by admin policy, for example) cannot be
+  // modified.
+  bool modifiable = !Extension::IsRequired(extension->location());

[Aaron Boodman, 2012/05/22 15:56:11]

It seems like if ManagementPolicy did this check itself, this implementation of
Provider would not be necessary.

[Pam (message me for reviews), 2012/05/23 15:00:58]

True, but the ManagementPolicy class is pretty abstract. I don't think it should
know that much detail about specific policies.

[Aaron Boodman, 2012/05/24 08:11:23]

I can see that. I just want to get this interface out of ExtensionService and
was thinking putting it in ManagementPolicy would solve the problem.

As we discussed offline, you could move these checks into extnsion_prefs.cc too.

+  // Some callers equate "no restriction" to true, others to false.
+  if (modifiable)
+    return modifiable_value;
+
+  if (error) {
+    *error = l10n_util::GetStringFUTF16(
+        IDS_EXTENSION_CANT_MODIFY_POLICY_REQUIRED,
+        UTF8ToUTF16(extension->name()));
+  }
+  return !modifiable_value;
+}
+
 void ExtensionService::EnableExtension(const std::string& extension_id) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (IsExtensionEnabled(extension_id))
     return;
 
   extension_prefs_->SetExtensionState(extension_id, Extension::ENABLED);
   extension_prefs_->RemoveDisableReason(extension_id);
 
   const Extension* extension =
@@ skipping 20 matching lines @@
     Extension::DisableReason disable_reason) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // The extension may have been disabled already.
   if (!IsExtensionEnabled(extension_id))
     return;
 
   const Extension* extension = GetInstalledExtension(extension_id);
   // |extension| can be NULL if sync disables an extension that is not
   // installed yet.
-  if (extension && !Extension::UserMayDisable(extension->location()))
+  if (extension &&
+      !system_->management_policy()->UserMayModifyStatus(extension, NULL)) {
     return;
+  }
 
   extension_prefs_->SetExtensionState(extension_id, Extension::DISABLED);
   extension_prefs_->SetDisableReason(extension_id, disable_reason);
 
   extension = GetExtensionByIdInternal(extension_id, true, false, true);
   if (!extension)
     return;
 
   // Move it over to the disabled list.
   disabled_extensions_.Insert(make_scoped_refptr(extension));
@@ skipping 284 matching lines @@
 extensions::ExtensionUpdater* ExtensionService::updater() {
   return updater_.get();
 }
 
 void ExtensionService::CheckAdminBlacklist() {
   std::vector<std::string> to_be_removed;
   // Loop through extensions list, unload installed extensions.
   for (ExtensionSet::const_iterator iter = extensions_.begin();
        iter != extensions_.end(); ++iter) {
     const Extension* extension = (*iter);
-    if (!extension_prefs_->IsExtensionAllowedByPolicy(extension->id(),
-                                                      extension->location())) {
+    if (!system_->management_policy()->UserMayLoad(extension,
+                                                   extension->location(),
+                                                   NULL)) {
       to_be_removed.push_back(extension->id());
     }
   }
 
   // UnloadExtension will change the extensions_ list. So, we should
   // call it outside the iterator loop.
   for (unsigned int i = 0; i < to_be_removed.size(); ++i)
     UnloadExtension(to_be_removed[i], extension_misc::UNLOAD_REASON_DISABLE);
 }
 
@@ skipping 921 matching lines @@
     const StringOrdinal& page_ordinal) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // Ensure extension is deleted unless we transfer ownership.
   scoped_refptr<const Extension> scoped_extension(extension);
   const std::string& id = extension->id();
   // Extensions installed by policy can't be disabled. So even if a previous
   // installation disabled the extension, make sure it is now enabled.
   bool initial_enable =
       !extension_prefs_->IsExtensionDisabled(id) ||
-      !Extension::UserMayDisable(extension->location());
+      system_->management_policy()->MustRemainEnabled(extension, NULL);
   PendingExtensionInfo pending_extension_info;
   if (pending_extension_manager()->GetById(id, &pending_extension_info)) {
     pending_extension_manager()->Remove(id);
 
     if (!pending_extension_info.ShouldAllowInstall(*extension)) {
       LOG(WARNING)
           << "ShouldAllowInstall() returned false for "
           << id << " of type " << extension->GetType()
           << " and update URL " << extension->update_url().spec()
           << "; not installing";
@@ skipping 437 matching lines @@
   // To coexist with certain unit tests that don't have an IO thread message
   // loop available at ExtensionService shutdown, we lazy-initialize this
   // object so that those cases neither create nor destroy an
   // APIResourceController.
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (!api_resource_controller_) {
     api_resource_controller_ = new extensions::APIResourceController();
   }
   return api_resource_controller_;
 }