Bluetooth low energy connection.

components/proximity_auth/ble/bluetooth_low_energy_connection.cc

Index: components/proximity_auth/ble/bluetooth_low_energy_connection.cc
diff --git a/components/proximity_auth/ble/bluetooth_low_energy_connection.cc b/components/proximity_auth/ble/bluetooth_low_energy_connection.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bb671b1a04b45c7881a5d1835e7a93b5c9920107
--- /dev/null
+++ b/components/proximity_auth/ble/bluetooth_low_energy_connection.cc
@@ -0,0 +1,274 @@
+// Copyright 2015 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/proximity_auth/ble/bluetooth_low_energy_connection.h"
+
+#include "base/bind.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "components/proximity_auth/connection_finder.h"
+#include "components/proximity_auth/ble/fake_wire_message.h"
+#include "components/proximity_auth/wire_message.h"
+#include "device/bluetooth/bluetooth_adapter.h"
+#include "device/bluetooth/bluetooth_device.h"
+#include "device/bluetooth/bluetooth_gatt_characteristic.h"
+#include "device/bluetooth/bluetooth_gatt_connection.h"
+#include "device/bluetooth/bluetooth_gatt_notify_session.h"
+#include "device/bluetooth/bluetooth_uuid.h"
+
+using device::BluetoothAdapter;
+using device::BluetoothDevice;
+using device::BluetoothGattConnection;
+using device::BluetoothGattService;
+using device::BluetoothGattCharacteristic;
+using device::BluetoothGattNotifySession;
+using device::BluetoothUUID;
+
+namespace proximity_auth {
+
+BluetoothLowEnergyConnection::BluetoothLowEnergyConnection(
+    const RemoteDevice& device,
+    scoped_refptr<device::BluetoothAdapter> adapter,
+    BluetoothUUID remote_service_uuid,
+    scoped_ptr<BluetoothGattConnection> gatt_connection)
+    : Connection(device),
+      adapter_(adapter),
+      remote_service_uuid_(remote_service_uuid),
+      connection_(gatt_connection.Pass()),
+      notify_session_pending_(false),
+      weak_ptr_factory_(this) {
+  if (connection_) {

[msarda, 2015/05/05 11:56:13]

Can |connection_| be null? If not, then it is better to DCHECK:
DCHECK(connection_)

[sacomoto, 2015/05/06 13:47:58]

Done.

+    SetStatus(IN_PROGRESS);
+  }
+
+  if (adapter_) {

[msarda, 2015/05/05 11:56:14]

DCHECK(adapter_)?

[sacomoto, 2015/05/06 13:47:58]

Done.

+    adapter_->AddObserver(this);
+  }
+}
+
+BluetoothLowEnergyConnection::~BluetoothLowEnergyConnection() {
+  Disconnect();
+  if (adapter_) {
+    adapter_->RemoveObserver(this);
+    adapter_ = NULL;
+  }
+}
+
+void BluetoothLowEnergyConnection::Connect() {
+  NOTREACHED();
+}
+
+void BluetoothLowEnergyConnection::Disconnect() {
+  StopNotifySession();
+  if (connection_) {
+    connection_.reset();
+    BluetoothDevice* device = GetRemoteDevice();
+    if (device) {
+      VLOG(1) << "Forget device " << device->GetAddress();
+      device->Forget(base::Bind(&base::DoNothing));

[msarda, 2015/05/05 11:56:14]

Please add a comment that disconnect actually forgets the remote BLE device.
Also comment why this is safe (the fact that it is SmarLock device).

[sacomoto, 2015/05/06 13:47:58]

Done.

+    }
+  }
+}
+
+// TODO(sacomoto): Send a Socketeer incoming signal. Implement a sender with

[msarda, 2015/05/05 11:56:13]

Remove all reference to Socketeer.

[sacomoto, 2015/05/06 13:47:58]

Done.

+// full support for messages larger than a single characteristic value.
+void BluetoothLowEnergyConnection::SendMessageImpl(
+    scoped_ptr<WireMessage> message) {
+  DCHECK(!GetGattCharacteristic(to_peripheral_char_id_));
+  VLOG(1) << "Sending message " << message->Serialize();
+
+  std::string serialized_message = message->Serialize();
+  std::vector<uint8> bytes(serialized_message.begin(),
+                           serialized_message.end());
+
+  GetGattCharacteristic(to_peripheral_char_id_)
+      ->WriteRemoteCharacteristic(
+          bytes, base::Bind(&base::DoNothing),
+          base::Bind(
+              &BluetoothLowEnergyConnection::OnWriteRemoteCharacteristicError,
+              weak_ptr_factory_.GetWeakPtr()));
+}
+
+void BluetoothLowEnergyConnection::DeviceRemoved(BluetoothAdapter* adapter,
+                                                 BluetoothDevice* device) {
+  if (device && device->GetAddress() == remote_device_address()) {
+    VLOG(1) << "device removed " << remote_device_address();

[msarda, 2015/05/05 11:56:13]

Log should state with CAPS:
s/device/Device

[sacomoto, 2015/05/06 13:47:57]

Done.

+    Disconnect();
+  }
+}
+
+void BluetoothLowEnergyConnection::GattDiscoveryCompleteForService(
+    BluetoothAdapter* adapter,
+    BluetoothGattService* service) {
+  if (service && service->GetUUID() == remote_service_uuid_) {
+    VLOG(1) << "All characteristics discovered for "
+            << remote_service_uuid_.canonical_value();
+
+    std::vector<device::BluetoothGattCharacteristic*> characteristics =
+        service->GetCharacteristics();
+    for (auto iter = characteristics.begin(); iter != characteristics.end();
+         iter++) {
+      HandleCharacteristicUpdate(*iter);
+    }
+
+    if (to_peripheral_char_id_.empty() || from_peripheral_char_id_.empty()) {
+      VLOG(1) << "Connection error, missing characteristics for service.";

[msarda, 2015/05/05 11:56:13]

s/service/Smart Lock service

[msarda, 2015/05/05 11:56:13]

Please also log which one of |to_peripheral_char_id_| and
|from_peripheral_char_id_| were not found.

[sacomoto, 2015/05/06 13:47:58]

Done.

[sacomoto, 2015/05/06 13:47:58]

Done.

+      Disconnect();
+    }
+  }
+}
+
+void BluetoothLowEnergyConnection::GattCharacteristicAdded(
+    BluetoothAdapter* adapter,
+    BluetoothGattCharacteristic* characteristic) {
+  VLOG(1) << "new char found: " << characteristic->GetUUID().canonical_value();
+  HandleCharacteristicUpdate(characteristic);
+}
+
+// TODO(sacomoto): Parse the Sockeeter incoming signal. Implement a receiver

[msarda, 2015/05/05 11:56:13]

Remove Socketeer.

[sacomoto, 2015/05/06 13:47:58]

Done.

+// with full suport for messages larger than a single characteristic value.
+void BluetoothLowEnergyConnection::GattCharacteristicValueChanged(
+    BluetoothAdapter* adapter,
+    BluetoothGattCharacteristic* characteristic,
+    const std::vector<uint8>& value) {
+  VLOG(1) << "Characteristic value changed: "
+          << characteristic->GetUUID().canonical_value();
+  if (characteristic->GetIdentifier() == from_peripheral_char_id_) {
+    std::string message(value.begin(), value.end());
+    VLOG(1) << "value: " << message;
+    // TODO(sacomoto): Actually handle the message and call OnBytesReceived when
+    // complete.
+  }
+}
+
+scoped_ptr<WireMessage> BluetoothLowEnergyConnection::DeserializeWireMessage(
+    bool* is_incomplete_message) {
+  return FakeWireMessage::Deserialize(received_bytes(), is_incomplete_message);
+}
+
+void BluetoothLowEnergyConnection::HandleCharacteristicUpdate(
+    BluetoothGattCharacteristic* characteristic) {
+  // Checks if |characteristic| is equal to |from_peripheral_char_| or
+  // |to_peripheral_char_| are present.
+  UpdateCharacteristicsStatus(characteristic);
+
+  // Starts a notify session for |from_peripheral_char_|.
+  if (characteristic->GetIdentifier() == from_peripheral_char_id_)
+    StartNotifySession();
+
+  // Checks if the connection is complete.
+  CompleteConnection();
+}
+
+void BluetoothLowEnergyConnection::CompleteConnection() {
+  if (status() == IN_PROGRESS && !to_peripheral_char_id_.empty() &&
+      !from_peripheral_char_id_.empty() && notify_session_) {
+    VLOG(1) << "Connection completed";
+    SetStatus(CONNECTED);
+    SendInviteToConnectSignal();

[msarda, 2015/05/05 11:56:13]

Should we wait for a reply to invite signal before actually changing the status
to CONNECTED?

[sacomoto, 2015/05/06 13:47:58]

Done.

+  }
+}
+
+void BluetoothLowEnergyConnection::StartNotifySession() {
+  BluetoothGattCharacteristic* characteristic =
+      GetGattCharacteristic(from_peripheral_char_id_);
+  if (!characteristic) {
+    VLOG(1) << "Characteristic " << from_peripheral_char_ << " not found.";
+    return;
+  }
+
+  if (notify_session_ || notify_session_pending_) {
+    VLOG(1) << "Notify session already started.";
+    return;
+  }
+
+  notify_session_pending_ = true;
+  characteristic->StartNotifySession(
+      base::Bind(&BluetoothLowEnergyConnection::OnNotifySessionStarted,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(&BluetoothLowEnergyConnection::OnNotifySessionError,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void BluetoothLowEnergyConnection::OnNotifySessionError(
+    BluetoothGattService::GattErrorCode error) {
+  VLOG(1) << "Error starting notification session: " << error;
+  notify_session_pending_ = false;
+}
+
+void BluetoothLowEnergyConnection::OnNotifySessionStarted(
+    scoped_ptr<BluetoothGattNotifySession> notify_session) {
+  VLOG(1) << "Notification session started "
+          << notify_session->GetCharacteristicIdentifier();
+  notify_session_ = notify_session.Pass();
+  notify_session_pending_ = false;
+
+  // Checks if the connection is complete.
+  CompleteConnection();
+}
+
+void BluetoothLowEnergyConnection::StopNotifySession() {
+  if (notify_session_) {
+    notify_session_->Stop(base::Bind(&base::DoNothing));
+    notify_session_.reset();
+  }
+}
+
+void BluetoothLowEnergyConnection::OnWriteRemoteCharacteristicError(
+    BluetoothGattService::GattErrorCode error) {
+  VLOG(1) << "Error writing characteristic" << to_peripheral_char_;
+}
+
+void BluetoothLowEnergyConnection::SendInviteToConnectSignal() {
+  // From Socketeer library: connect signal is 0 (32-bit int).
+  const char connect_signal[4] = {};
+  SendMessage(scoped_ptr<FakeWireMessage>(new FakeWireMessage(connect_signal)));
+}
+
+void BluetoothLowEnergyConnection::UpdateCharacteristicsStatus(
+    BluetoothGattCharacteristic* characteristic) {
+  if (characteristic) {
+    std::string canonical_value = characteristic->GetUUID().canonical_value();
+    VLOG(1) << canonical_value;
+    if (to_peripheral_char_ == canonical_value) {
+      to_peripheral_char_id_ = characteristic->GetIdentifier();
+    }
+    if (from_peripheral_char_ == canonical_value) {
+      from_peripheral_char_id_ = characteristic->GetIdentifier();
+    }
+    BluetoothGattService* service = characteristic->GetService();
+    if (service && service->GetUUID() == remote_service_uuid_)
+      remote_service_id_ = service->GetIdentifier();
+  }
+}
+
+BluetoothDevice* BluetoothLowEnergyConnection::GetRemoteDevice() {
+  if (!adapter_ || !adapter_->IsInitialized()) {
+    VLOG(1) << "adapter not ready";
+    return NULL;
+  }
+  return adapter_->GetDevice(remote_device_address());
+}
+
+BluetoothGattService* BluetoothLowEnergyConnection::GetRemoteService() {
+  BluetoothDevice* remote_device = GetRemoteDevice();
+  if (!remote_device) {
+    VLOG(1) << "device not found";
+    return NULL;
+  }
+  return remote_device->GetGattService(remote_service_id_);
+}
+
+BluetoothGattCharacteristic*
+BluetoothLowEnergyConnection::GetGattCharacteristic(
+    const std::string& gatt_characteristic) {
+  BluetoothGattService* remote_service = GetRemoteService();
+  if (!remote_service) {
+    VLOG(1) << "service not found";
+    return NULL;
+  }
+  return remote_service->GetCharacteristic(gatt_characteristic);
+}
+
+}  // namespace proximity_auth