Chrome OS uWeave Characteristics Server

components/proximity_auth/ble/bluetooth_low_energy_weave_server.h

+// Copyright 2016 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 COMPONENTS_PROXIMITY_AUTH_BLE_BLUETOOTH_LOW_ENERGY_WEAVE_SERVER_H_
+#define COMPONENTS_PROXIMITY_AUTH_BLE_BLUETOOTH_LOW_ENERGY_WEAVE_SERVER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "base/task_runner.h"
+#include "components/proximity_auth/ble/bluetooth_low_energy_advertisement_rotator.h"
+#include "components/proximity_auth/ble/bluetooth_low_energy_weave_defines.h"
+#include "components/proximity_auth/ble/bluetooth_low_energy_weave_server_connection.h"
+#include "components/proximity_auth/connection.h"
+#include "components/proximity_auth/remote_device.h"
+#include "device/bluetooth/bluetooth_adapter.h"
+#include "device/bluetooth/bluetooth_device.h"
+#include "device/bluetooth/bluetooth_local_gatt_characteristic.h"
+#include "device/bluetooth/bluetooth_local_gatt_descriptor.h"
+#include "device/bluetooth/bluetooth_local_gatt_service.h"
+
+namespace base {
+class TaskRunner;
+}
+
+namespace proximity_auth {
+namespace weave {
+namespace {
+
+using BluetoothAdapter = device::BluetoothAdapter;
+using BluetoothAdvertisement = device::BluetoothAdvertisement;
+using BluetoothDevice = device::BluetoothDevice;
+using BluetoothLocalGattCharacteristic =
+    device::BluetoothLocalGattCharacteristic;
+using BluetoothLocalGattService = device::BluetoothLocalGattService;
+using BluetoothLocalGattDescriptor = device::BluetoothLocalGattDescriptor;
+using ValueCallback = base::Callback<void(const std::vector<uint8_t>&)>;
+using ErrorCallback = base::Closure;
+using ConnectionStatus = proximity_auth::Connection::Status;
+
+}  // namespace
+
+class BluetoothLowEnergyWeaveServerConnection;
+
+// Represent a server for device's connection requests.
+// Listens for requests from registered devices on the RX and TX
+// characteristics.
+// A registered device is either being advertised to or connected with the
+// server.
+// If a device is being advertised to, the advertisement could either be
+// registered on the adapter or waiting on the queue in advertisement rotator.
+// The device must be in the ad_rotator_ but its corresponding advertisement
+// may or may not be advertising at one moment.
+class BluetoothLowEnergyWeaveServer
+    : public device::BluetoothLocalGattService::Delegate {
+ public:
+  class Factory {
+   public:
+    static std::unique_ptr<BluetoothLowEnergyWeaveServer> NewInstance();
+
+    // Exposed for testing.
+    static void SetInstanceForTesting(Factory* factory);
+
+   protected:
+    // Exposed for testing.
+    virtual std::unique_ptr<BluetoothLowEnergyWeaveServer> BuildInstance();
+
+   private:
+    static Factory* factory_instance_;
+  };
+
+  // TODO(jingxuy): The observer for this class.
+
+  // device::BluetoothLocalGattService::Delegate:
+  void OnCharacteristicReadRequest(
+      const BluetoothDevice* bluetooth_device,
+      const BluetoothLocalGattCharacteristic* characteristic,
+      int offset,
+      const ValueCallback& callback,
+      const ErrorCallback& error_callback) override;
+
+  // If the write request is from a known device and the TX characteristic,
+  // then forward |value| to the appropriate ServerConnection of that device.
+  void OnCharacteristicWriteRequest(
+      const BluetoothDevice* bluetooth_device,
+      const BluetoothLocalGattCharacteristic* characteristic,
+      const Packet& value,
+      int offset,
+      const base::Closure& callback,
+      const ErrorCallback& error_callback) override;
+
+  void OnDescriptorReadRequest(const BluetoothDevice* device,
+                               const BluetoothLocalGattDescriptor* descriptor,
+                               int offset,
+                               const ValueCallback& callback,
+                               const ErrorCallback& error_callback) override {}
+
+  void OnDescriptorWriteRequest(const BluetoothDevice* device,
+                                const BluetoothLocalGattDescriptor* descriptor,
+                                const std::vector<uint8_t>& value,
+                                int offset,
+                                const base::Closure& callback,
+                                const ErrorCallback& error_callback) override {}
+
+  void OnNotificationsStart(
+      const BluetoothDevice* bluetooth_device,
+      const BluetoothLocalGattCharacteristic* characteristic) override;
+
+  void OnNotificationsStop(
+      const BluetoothDevice* bluetooth_device,
+      const BluetoothLocalGattCharacteristic* characteristic) override;
+
+  ~BluetoothLowEnergyWeaveServer();
+
+  // |remote_device| must not share a bluetooth_address with any device already
+  // registered.
+  // Registration effectively puts the device in advertisement queue.
+  void RegisterDevice(const RemoteDevice& remote_device);
+
+  // |remote_device| must already be registered.
+  // If the device is advertising, the advertisement will be taken down.
+  // If the device is connected, it will be disconnected immediately.
+  void UnregisterDevice(const RemoteDevice& remote_device);
+
+  bool HasDevice(std::string device_address);
+
+  const RemoteDevice& GetRemoteDevice(const BluetoothDevice* bluetooth_device);
+
+  // |remote_device| must already be registered and not advertisement enabled.
+  void EnableAdvertising(const RemoteDevice& remote_device);
+
+  // |remote_device| must already be registered and advertisement enabled.
+  void DisableAdvertising(const RemoteDevice& remote_device);
+
+ protected:
+  BluetoothLowEnergyWeaveServer();
+
+  // Sets |task_runner_| for testing.
+  void SetTaskRunnerForTesting(scoped_refptr<base::TaskRunner> task_runner);
+
+ private:
+  bool IsAdvertising(std::string bluetooth_address);
+  bool IsConnected(std::string bluetooth_address);
+
+  // Rotating function for refreshing the EID seed. Will post itself on the
+  // task runner upon completion to run at the next 14 day refresh boundary.
+  void UpdateEidSeeds();
+
+  // Rotating function for refreshing the EID. Will post itself on the task
+  // runner upon completion to run at the next 8 hour refresh boundary.
+  void UpdateEids();
+
+  // Refresh the currently registered functions. Since the currently registered
+  // advertisements could not be modified, unregister them and tries to
+  // re-register them. If they are not re-registered, they are guarnateed to be
+  // on the front of the advertisement queue.
+  void RefreshAdvertisement();
+
+  // Rotating function for giving other devices a fair share of the advertising
+  // time slot. Will post itself on the task runner upon completion to run in
+  // 5 seconds.
+  void RotateAdvertisement();
+
+  // Helper to attempt to register an advertisement.
+  void Advertise();
+
+  void UnregisterAdvertisement(std::string bluetooth_address);
+
+  // Remove the advertisement from map_to_advertisement_ because it's no longer
+  // advertising.
+  void UnregisterAdvertisementSuccess(std::string bluetooth_address);
+
+  // This should not happen.
+  void UnregisterAdvertisementError(std::string bluetooth_address,
+                                    BluetoothAdvertisement::ErrorCode error);
+
+  // If it's a success, then rotate the ad_rotator_ to go to the next
+  // advertisement and attempt to register that one.
+  void RegisterAdvertisementSuccess(
+      std::string bluetooth_address,
+      scoped_refptr<BluetoothAdvertisement> advertisement);
+
+  // Stop the rolling advertisement process by doing nothing.
+  // TODO(jingxuu): do I need to log anything?
+  void RegisterAdvertisementError(BluetoothAdvertisement::ErrorCode error) {}
+
+  // TODO(jingxuu): currently this is an empty function, unsure whether if
+  // anything needed to be done when the adapter is created.
+  void CreateAdapterCallback() {}
+
+  scoped_refptr<base::TaskRunner> task_runner_;
+
+  // All registered devices included here.
+  std::map<std::string, RemoteDevice> map_to_remote_device_;
+
+  std::unique_ptr<BluetoothLowEnergyAdvertisementRotator> ad_rotator_;
+
+  // The currently registered advertisements.
+  std::map<std::string, scoped_refptr<BluetoothAdvertisement>>
+      map_to_advertisement_;
+
+  // The currently active connections. One connection per device allowed.
+  std::map<std::string,
+           std::unique_ptr<BluetoothLowEnergyWeaveServerConnection>>
+      map_to_server_connection_;
+
+  scoped_refptr<BluetoothAdapter> adapter_;
+
+  base::WeakPtr<BluetoothLocalGattService> service_;
+
+  base::WeakPtr<BluetoothLocalGattCharacteristic> rx_characteristic_;
+  base::WeakPtr<BluetoothLocalGattCharacteristic> tx_characteristic_;
+
+  base::WeakPtrFactory<BluetoothLowEnergyWeaveServer> weak_ptr_factory_;
+};
+
+}  // namespace weave
+
+}  // namespace proximity_auth
+
+#endif  // COMPONENTS_PROXIMITY_AUTH_BLE_BLUETOOTH_LOW_ENERGY_WEAVE_SERVER_H_