root/components/policy/core/common/cloud/component_cloud_policy_service.cc

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DEFINITIONS

This source file includes following definitions.
  1. NotInSchemaMap
  2. ToPolicyNamespaceKey
  3. ToPolicyNamespace
  4. store_
  5. SetCredentials
  6. Init
  7. UpdateExternalPolicy
  8. OnComponentCloudPolicyStoreUpdated
  9. OnSchemasUpdated
  10. weak_ptr_factory_
  11. SupportsDomain
  12. ClearCache
  13. OnSchemaRegistryReady
  14. OnSchemaRegistryUpdated
  15. OnCoreConnected
  16. OnCoreDisconnecting
  17. OnRefreshSchedulerStarted
  18. OnStoreLoaded
  19. OnStoreError
  20. OnPolicyFetched
  21. OnRegistrationStateChanged
  22. OnClientError
  23. InitializeIfReady
  24. OnBackendInitialized
  25. SetCurrentSchema
  26. OnPolicyUpdated

// Copyright (c) 2013 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 "components/policy/core/common/cloud/component_cloud_policy_service.h"

#include <string>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/message_loop/message_loop_proxy.h"
#include "base/sequenced_task_runner.h"
#include "components/policy/core/common/cloud/cloud_policy_constants.h"
#include "components/policy/core/common/cloud/cloud_policy_refresh_scheduler.h"
#include "components/policy/core/common/cloud/component_cloud_policy_store.h"
#include "components/policy/core/common/cloud/component_cloud_policy_updater.h"
#include "components/policy/core/common/cloud/external_policy_data_fetcher.h"
#include "components/policy/core/common/cloud/resource_cache.h"
#include "components/policy/core/common/schema.h"
#include "components/policy/core/common/schema_map.h"
#include "net/url_request/url_request_context_getter.h"
#include "policy/proto/device_management_backend.pb.h"

namespace em = enterprise_management;

namespace policy {

namespace {

bool NotInSchemaMap(const scoped_refptr<SchemaMap> schema_map,
                    PolicyDomain domain,
                    const std::string& component_id) {
  return schema_map->GetSchema(PolicyNamespace(domain, component_id)) == NULL;
}

bool ToPolicyNamespaceKey(const PolicyNamespace& ns, PolicyNamespaceKey* key) {
  if (!ComponentCloudPolicyStore::GetPolicyType(ns.domain, &key->first))
    return false;
  key->second = ns.component_id;
  return true;
}

bool ToPolicyNamespace(const PolicyNamespaceKey& key, PolicyNamespace* ns) {
  if (!ComponentCloudPolicyStore::GetPolicyDomain(key.first, &ns->domain))
    return false;
  ns->component_id = key.second;
  return true;
}

}  // namespace

ComponentCloudPolicyService::Delegate::~Delegate() {}

// Owns the objects that live on the background thread, and posts back to the
// thread that the ComponentCloudPolicyService runs on whenever the policy
// changes.
class ComponentCloudPolicyService::Backend
    : public ComponentCloudPolicyStore::Delegate {
 public:
  // This class can be instantiated on any thread but from then on, may be
  // accessed via the |task_runner_| only. Policy changes are posted to the
  // |service| via the |service_task_runner|. The |cache| is used to load and
  // store local copies of the downloaded policies.
  Backend(base::WeakPtr<ComponentCloudPolicyService> service,
          scoped_refptr<base::SequencedTaskRunner> task_runner,
          scoped_refptr<base::SequencedTaskRunner> service_task_runner,
          scoped_ptr<ResourceCache> cache,
          scoped_ptr<ExternalPolicyDataFetcher> external_policy_data_fetcher);

  virtual ~Backend();

  // |username| and |dm_token| will be  used to validate the cached policies.
  void SetCredentials(const std::string& username, const std::string& dm_token);

  // Loads the |store_| and starts downloading updates.
  void Init(scoped_refptr<SchemaMap> schema_map);

  // Passes a policy protobuf to the backend, to start its validation and
  // eventual download of the policy data on the background thread.
  void UpdateExternalPolicy(scoped_ptr<em::PolicyFetchResponse> response);

  // ComponentCloudPolicyStore::Delegate implementation:
  virtual void OnComponentCloudPolicyStoreUpdated() OVERRIDE;

  // Passes the current SchemaMap so that the disk cache can purge components
  // that aren't being tracked anymore.
  // |removed| is a list of namespaces that were present in the previous
  // schema and have been removed in the updated version.
  void OnSchemasUpdated(scoped_refptr<SchemaMap> schema_map,
                        scoped_ptr<PolicyNamespaceList> removed);

 private:
  // The ComponentCloudPolicyService that owns |this|. Used to inform the
  // |service_| when policy changes.
  base::WeakPtr<ComponentCloudPolicyService> service_;

  // The thread that |this| runs on. Used to post tasks to be run by |this|.
  scoped_refptr<base::SequencedTaskRunner> task_runner_;

  // The thread that the |service_| runs on. Used to post policy changes to the
  // right thread.
  scoped_refptr<base::SequencedTaskRunner> service_task_runner_;

  scoped_ptr<ResourceCache> cache_;
  scoped_ptr<ExternalPolicyDataFetcher> external_policy_data_fetcher_;
  ComponentCloudPolicyStore store_;
  scoped_ptr<ComponentCloudPolicyUpdater> updater_;
  scoped_refptr<SchemaMap> schema_map_;

  DISALLOW_COPY_AND_ASSIGN(Backend);
};

ComponentCloudPolicyService::Backend::Backend(
    base::WeakPtr<ComponentCloudPolicyService> service,
    scoped_refptr<base::SequencedTaskRunner> task_runner,
    scoped_refptr<base::SequencedTaskRunner> service_task_runner,
    scoped_ptr<ResourceCache> cache,
    scoped_ptr<ExternalPolicyDataFetcher> external_policy_data_fetcher)
    : service_(service),
      task_runner_(task_runner),
      service_task_runner_(service_task_runner),
      cache_(cache.Pass()),
      external_policy_data_fetcher_(external_policy_data_fetcher.Pass()),
      store_(this, cache_.get()) {}

ComponentCloudPolicyService::Backend::~Backend() {}

void ComponentCloudPolicyService::Backend::SetCredentials(
    const std::string& username,
    const std::string& dm_token) {
  if (username.empty() || dm_token.empty()) {
    // No sign-in credentials, so drop any cached policy.
    store_.Clear();
  } else {
    store_.SetCredentials(username, dm_token);
  }
}

void ComponentCloudPolicyService::Backend::Init(
    scoped_refptr<SchemaMap> schema_map) {
  DCHECK(!schema_map_);

  OnSchemasUpdated(schema_map, scoped_ptr<PolicyNamespaceList>());

  // Read the initial policy. Note that this does not trigger notifications
  // through OnComponentCloudPolicyStoreUpdated. Note also that the cached
  // data may contain names or values that don't match the schema for that
  // component; the data must be cached without modifications so that its
  // integrity can be verified using the hash, but it must also be filtered
  // right after a Load().
  store_.Load();
  scoped_ptr<PolicyBundle> bundle(new PolicyBundle);
  bundle->CopyFrom(store_.policy());
  schema_map_->FilterBundle(bundle.get());

  // Start downloading any pending data.
  updater_.reset(new ComponentCloudPolicyUpdater(
      task_runner_, external_policy_data_fetcher_.Pass(), &store_));

  service_task_runner_->PostTask(
      FROM_HERE,
      base::Bind(&ComponentCloudPolicyService::OnBackendInitialized,
                 service_,
                 base::Passed(&bundle)));
}

void ComponentCloudPolicyService::Backend::UpdateExternalPolicy(
    scoped_ptr<em::PolicyFetchResponse> response) {
  updater_->UpdateExternalPolicy(response.Pass());
}

void ComponentCloudPolicyService::Backend::
    OnComponentCloudPolicyStoreUpdated() {
  if (!schema_map_) {
    // Ignore notifications triggered by the initial Purge or Clear.
    return;
  }

  scoped_ptr<PolicyBundle> bundle(new PolicyBundle);
  bundle->CopyFrom(store_.policy());
  schema_map_->FilterBundle(bundle.get());
  service_task_runner_->PostTask(
      FROM_HERE,
      base::Bind(&ComponentCloudPolicyService::OnPolicyUpdated,
                 service_,
                 base::Passed(&bundle)));
}

void ComponentCloudPolicyService::Backend::OnSchemasUpdated(
    scoped_refptr<SchemaMap> schema_map,
    scoped_ptr<PolicyNamespaceList> removed) {
  // Purge any components that have been removed.
  const DomainMap& domains = schema_map->GetDomains();
  for (DomainMap::const_iterator domain = domains.begin();
       domain != domains.end(); ++domain) {
    store_.Purge(domain->first,
                 base::Bind(&NotInSchemaMap, schema_map, domain->first));
  }

  // Set |schema_map_| after purging so that the notifications from the store
  // are ignored on the first OnSchemasUpdated() call from Init().
  schema_map_ = schema_map;

  if (removed) {
    for (size_t i = 0; i < removed->size(); ++i)
      updater_->CancelUpdate((*removed)[i]);
  }
}

ComponentCloudPolicyService::ComponentCloudPolicyService(
    Delegate* delegate,
    SchemaRegistry* schema_registry,
    CloudPolicyCore* core,
    scoped_ptr<ResourceCache> cache,
    scoped_refptr<net::URLRequestContextGetter> request_context,
    scoped_refptr<base::SequencedTaskRunner> backend_task_runner,
    scoped_refptr<base::SequencedTaskRunner> io_task_runner)
    : delegate_(delegate),
      schema_registry_(schema_registry),
      core_(core),
      request_context_(request_context),
      backend_task_runner_(backend_task_runner),
      io_task_runner_(io_task_runner),
      current_schema_map_(new SchemaMap),
      started_loading_initial_policy_(false),
      loaded_initial_policy_(false),
      is_registered_for_cloud_policy_(false),
      weak_ptr_factory_(this) {
  external_policy_data_fetcher_backend_.reset(
      new ExternalPolicyDataFetcherBackend(io_task_runner_, request_context));

  backend_.reset(
      new Backend(weak_ptr_factory_.GetWeakPtr(),
                  backend_task_runner_,
                  base::MessageLoopProxy::current(),
                  cache.Pass(),
                  external_policy_data_fetcher_backend_->CreateFrontend(
                      backend_task_runner_)));

  schema_registry_->AddObserver(this);
  core_->store()->AddObserver(this);

  // Wait for the store and the schema registry to become ready before
  // initializing the backend, so that it can get the initial list of
  // components and the cached credentials (if any) to validate the cached
  // policies.
  if (core_->store()->is_initialized())
    OnStoreLoaded(core_->store());
}

ComponentCloudPolicyService::~ComponentCloudPolicyService() {
  DCHECK(CalledOnValidThread());

  schema_registry_->RemoveObserver(this);
  core_->store()->RemoveObserver(this);
  core_->RemoveObserver(this);
  if (core_->client())
    OnCoreDisconnecting(core_);

  io_task_runner_->DeleteSoon(FROM_HERE,
                              external_policy_data_fetcher_backend_.release());
  backend_task_runner_->DeleteSoon(FROM_HERE, backend_.release());
}

// static
bool ComponentCloudPolicyService::SupportsDomain(PolicyDomain domain) {
  return ComponentCloudPolicyStore::SupportsDomain(domain);
}

void ComponentCloudPolicyService::ClearCache() {
  DCHECK(CalledOnValidThread());
  // Empty credentials will wipe the cache.
  backend_task_runner_->PostTask(FROM_HERE,
                                 base::Bind(&Backend::SetCredentials,
                                            base::Unretained(backend_.get()),
                                            std::string(), std::string()));
}

void ComponentCloudPolicyService::OnSchemaRegistryReady() {
  DCHECK(CalledOnValidThread());
  InitializeIfReady();
}

void ComponentCloudPolicyService::OnSchemaRegistryUpdated(
    bool has_new_schemas) {
  DCHECK(CalledOnValidThread());

  // Ignore schema updates until the backend is initialized.
  // OnBackendInitialized() will send the current schema to the backend again,
  // in case it was updated before the backend initialized.
  if (!loaded_initial_policy_)
    return;

  SetCurrentSchema();
}

void ComponentCloudPolicyService::OnCoreConnected(CloudPolicyCore* core) {
  DCHECK(CalledOnValidThread());
  DCHECK_EQ(core_, core);

  core_->client()->AddObserver(this);

  // Immediately load any PolicyFetchResponses that the client may already
  // have.
  OnPolicyFetched(core_->client());

  // Register the current namespaces at the client.
  current_schema_map_ = new SchemaMap();
  SetCurrentSchema();
}

void ComponentCloudPolicyService::OnCoreDisconnecting(CloudPolicyCore* core) {
  DCHECK(CalledOnValidThread());
  DCHECK_EQ(core_, core);

  core_->client()->RemoveObserver(this);

  // Remove all the namespaces from the client.
  scoped_refptr<SchemaMap> empty = new SchemaMap();
  PolicyNamespaceList removed;
  PolicyNamespaceList added;
  empty->GetChanges(current_schema_map_, &removed, &added);
  for (size_t i = 0; i < removed.size(); ++i) {
    PolicyNamespaceKey key;
    if (ToPolicyNamespaceKey(removed[i], &key))
      core_->client()->RemoveNamespaceToFetch(key);
  }
}

void ComponentCloudPolicyService::OnRefreshSchedulerStarted(
    CloudPolicyCore* core) {
  // Ignored.
}

void ComponentCloudPolicyService::OnStoreLoaded(CloudPolicyStore* store) {
  DCHECK(CalledOnValidThread());
  DCHECK_EQ(core_->store(), store);

  const bool was_registered_before = is_registered_for_cloud_policy_;

  // Send the current credentials to the backend; do this whenever the store
  // updates, to handle the case of the user registering for policy after the
  // session starts, or the user signing out.
  const em::PolicyData* policy = core_->store()->policy();
  std::string username;
  std::string request_token;
  if (policy && policy->has_username() && policy->has_request_token()) {
    is_registered_for_cloud_policy_ = true;
    username = policy->username();
    request_token = policy->request_token();
  } else {
    is_registered_for_cloud_policy_ = false;
  }

  // Empty credentials will wipe the cache.
  backend_task_runner_->PostTask(FROM_HERE,
                                 base::Bind(&Backend::SetCredentials,
                                            base::Unretained(backend_.get()),
                                            username,
                                            request_token));

  if (!loaded_initial_policy_) {
    // This is the initial load; check if we're ready to initialize the
    // backend, regardless of the signin state.
    InitializeIfReady();
  } else if (!was_registered_before && is_registered_for_cloud_policy_) {
    // We are already initialized, but just sent credentials to the backend for
    // the first time; this means that the user was not registered for cloud
    // policy on startup but registered during the session.
    //
    // When that happens, OnPolicyFetched() is sent to observers before the
    // CloudPolicyStore gets a chance to verify the user policy. In those cases,
    // the backend gets the PolicyFetchResponses before it has the credentials
    // and therefore the validation of those responses fails.
    // Reload any PolicyFetchResponses that the client may have now so that
    // validation is retried with the credentials in place.
    if (core_->client())
      OnPolicyFetched(core_->client());
  }
}

void ComponentCloudPolicyService::OnStoreError(CloudPolicyStore* store) {
  DCHECK(CalledOnValidThread());
  OnStoreLoaded(store);
}

void ComponentCloudPolicyService::OnPolicyFetched(CloudPolicyClient* client) {
  DCHECK(CalledOnValidThread());
  DCHECK_EQ(core_->client(), client);

  if (!is_registered_for_cloud_policy_) {
    // Trying to load any policies now will fail validation. An OnStoreLoaded()
    // notification should follow soon, after the main user policy has been
    // validated and stored.
    return;
  }

  // Pass each PolicyFetchResponse whose policy type is registered to the
  // Backend.
  const CloudPolicyClient::ResponseMap& responses =
      core_->client()->responses();
  for (CloudPolicyClient::ResponseMap::const_iterator it = responses.begin();
       it != responses.end(); ++it) {
    PolicyNamespace ns;
    if (ToPolicyNamespace(it->first, &ns) &&
        current_schema_map_->GetSchema(ns)) {
      scoped_ptr<em::PolicyFetchResponse> response(
          new em::PolicyFetchResponse(*it->second));
      backend_task_runner_->PostTask(
          FROM_HERE,
          base::Bind(&Backend::UpdateExternalPolicy,
                     base::Unretained(backend_.get()),
                     base::Passed(&response)));
    }
  }
}

void ComponentCloudPolicyService::OnRegistrationStateChanged(
    CloudPolicyClient* client) {
  DCHECK(CalledOnValidThread());
  // Ignored; the registration state is tracked by looking at the
  // CloudPolicyStore instead.
}

void ComponentCloudPolicyService::OnClientError(CloudPolicyClient* client) {
  DCHECK(CalledOnValidThread());
  // Ignored.
}

void ComponentCloudPolicyService::InitializeIfReady() {
  DCHECK(CalledOnValidThread());
  if (started_loading_initial_policy_ || !schema_registry_->IsReady() ||
      !core_->store()->is_initialized()) {
    return;
  }
  // The initial list of components is ready. Initialize the backend now, which
  // will call back to OnBackendInitialized.
  backend_task_runner_->PostTask(FROM_HERE,
                                 base::Bind(&Backend::Init,
                                            base::Unretained(backend_.get()),
                                            schema_registry_->schema_map()));
  started_loading_initial_policy_ = true;
}

void ComponentCloudPolicyService::OnBackendInitialized(
    scoped_ptr<PolicyBundle> initial_policy) {
  DCHECK(CalledOnValidThread());
  DCHECK(!loaded_initial_policy_);

  loaded_initial_policy_ = true;

  // We're now ready to serve the initial policy; notify the policy observers.
  OnPolicyUpdated(initial_policy.Pass());

  // Start observing the core and tracking the state of the client.
  core_->AddObserver(this);

  if (core_->client()) {
    OnCoreConnected(core_);
  } else {
    // Send the current schema to the backend, in case it has changed while the
    // backend was initializing. OnCoreConnected() also does this if a client is
    // already connected.
    SetCurrentSchema();
  }
}

void ComponentCloudPolicyService::SetCurrentSchema() {
  DCHECK(CalledOnValidThread());

  scoped_ptr<PolicyNamespaceList> removed(new PolicyNamespaceList);
  PolicyNamespaceList added;
  const scoped_refptr<SchemaMap>& new_schema_map =
      schema_registry_->schema_map();
  new_schema_map->GetChanges(current_schema_map_, removed.get(), &added);

  current_schema_map_ = new_schema_map;

  if (core_->client()) {
    for (size_t i = 0; i < removed->size(); ++i) {
      PolicyNamespaceKey key;
      if (ToPolicyNamespaceKey((*removed)[i], &key))
        core_->client()->RemoveNamespaceToFetch(key);
    }

    bool added_namespaces_to_client = false;
    for (size_t i = 0; i < added.size(); ++i) {
      PolicyNamespaceKey key;
      if (ToPolicyNamespaceKey(added[i], &key)) {
        core_->client()->AddNamespaceToFetch(key);
        added_namespaces_to_client = true;
      }
    }

    if (added_namespaces_to_client)
      core_->RefreshSoon();
  }

  backend_task_runner_->PostTask(FROM_HERE,
                                 base::Bind(&Backend::OnSchemasUpdated,
                                            base::Unretained(backend_.get()),
                                            current_schema_map_,
                                            base::Passed(&removed)));
}

void ComponentCloudPolicyService::OnPolicyUpdated(
    scoped_ptr<PolicyBundle> policy) {
  DCHECK(CalledOnValidThread());
  policy_.Swap(policy.get());
  delegate_->OnComponentCloudPolicyUpdated();
}

}  // namespace policy

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