components/proximity_auth/ble/bluetooth_low_energy_characteristics_finder.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/proximity_auth/ble/bluetooth_low_energy_characteristics_finder.h"
   6
   7 #include "components/proximity_auth/logging/logging.h"
   8 #include "device/bluetooth/bluetooth_adapter.h"
   9 #include "device/bluetooth/bluetooth_device.h"
  10 #include "device/bluetooth/bluetooth_gatt_characteristic.h"
  11 #include "device/bluetooth/bluetooth_uuid.h"
  12
  13 using device::BluetoothAdapter;
  14 using device::BluetoothDevice;
  15 using device::BluetoothGattCharacteristic;
  16 using device::BluetoothGattService;
  17 using device::BluetoothUUID;
  18
  19 namespace proximity_auth {
  20
  21 BluetoothLowEnergyCharacteristicsFinder::
  22     BluetoothLowEnergyCharacteristicsFinder(
  23         scoped_refptr<BluetoothAdapter> adapter,
  24         BluetoothDevice* device,
  25         const RemoteAttribute& remote_service,
  26         const RemoteAttribute& to_peripheral_char,
  27         const RemoteAttribute& from_peripheral_char,
  28         const SuccessCallback& success_callback,
  29         const ErrorCallback& error_callback)
  30     : adapter_(adapter),
  31       remote_service_(remote_service),
  32       to_peripheral_char_(to_peripheral_char),
  33       from_peripheral_char_(from_peripheral_char),
  34       success_callback_(success_callback),
  35       error_callback_(error_callback) {
  36   if (!adapter_) {
  37     error_callback_.Run(to_peripheral_char_, from_peripheral_char_);
  38     ResetCallbacks();
  39     return;
  40   }
  41
  42   adapter_->AddObserver(this);
  43   ScanRemoteCharacteristics(device, remote_service_.uuid);
  44
  45   // TODO(sacomoto): implement a timeout for characteristic discovery.
  46 }
  47
  48 BluetoothLowEnergyCharacteristicsFinder::
  49     BluetoothLowEnergyCharacteristicsFinder() {
  50 }
  51
  52 BluetoothLowEnergyCharacteristicsFinder::
  53     ~BluetoothLowEnergyCharacteristicsFinder() {
  54   ResetCallbacks();
  55   if (adapter_) {
  56     adapter_->RemoveObserver(this);
  57     adapter_ = NULL;
  58   }
  59 }
  60
  61 void BluetoothLowEnergyCharacteristicsFinder::GattCharacteristicAdded(
  62     BluetoothAdapter* adapter,
  63     BluetoothGattCharacteristic* characteristic) {
  64   PA_LOG(INFO) << "New char found: "
  65                << characteristic->GetUUID().canonical_value();
  66   HandleCharacteristicUpdate(characteristic);
  67 }
  68
  69 void BluetoothLowEnergyCharacteristicsFinder::GattDiscoveryCompleteForService(
  70     BluetoothAdapter* adapter,
  71     BluetoothGattService* service) {
  72   if (service && service->GetUUID() == remote_service_.uuid) {
  73     PA_LOG(INFO) << "All characteristics discovered for "
  74                  << remote_service_.uuid.canonical_value();
  75
  76     if (to_peripheral_char_.id.empty() || from_peripheral_char_.id.empty()) {
  77       if (!error_callback_.is_null()) {
  78         error_callback_.Run(to_peripheral_char_, from_peripheral_char_);
  79         ResetCallbacks();
  80       }
  81     }
  82   }
  83 }
  84
  85 void BluetoothLowEnergyCharacteristicsFinder::ScanRemoteCharacteristics(
  86     BluetoothDevice* device,
  87     const BluetoothUUID& service_uuid) {
  88   PA_LOG(INFO) << "Scanning remote characteristics.";
  89   if (device) {
  90     std::vector<BluetoothGattService*> services = device->GetGattServices();
  91     for (const auto& service : services) {
  92       if (service->GetUUID() == service_uuid) {
  93         // Right service found, now scaning its characteristics.
  94         std::vector<device::BluetoothGattCharacteristic*> characteristics =
  95             service->GetCharacteristics();
  96         for (const auto& characteristic : characteristics) {
  97           HandleCharacteristicUpdate(characteristic);
  98         }
  99         break;
 100       }
 101     }
 102   }
 103 }
 104
 105 void BluetoothLowEnergyCharacteristicsFinder::HandleCharacteristicUpdate(
 106     BluetoothGattCharacteristic* characteristic) {
 107   UpdateCharacteristicsStatus(characteristic);
 108
 109   if (!to_peripheral_char_.id.empty() && !from_peripheral_char_.id.empty() &&
 110       !success_callback_.is_null()) {
 111     PA_LOG(INFO) << "Found write and read characteristics on remote device.";
 112     success_callback_.Run(remote_service_, to_peripheral_char_,
 113                           from_peripheral_char_);
 114     ResetCallbacks();
 115   }
 116 }
 117
 118 void BluetoothLowEnergyCharacteristicsFinder::UpdateCharacteristicsStatus(
 119     BluetoothGattCharacteristic* characteristic) {
 120   if (characteristic &&
 121       characteristic->GetService()->GetUUID() == remote_service_.uuid) {
 122     BluetoothUUID uuid = characteristic->GetUUID();
 123     if (to_peripheral_char_.uuid == uuid)
 124       to_peripheral_char_.id = characteristic->GetIdentifier();
 125     if (from_peripheral_char_.uuid == uuid)
 126       from_peripheral_char_.id = characteristic->GetIdentifier();
 127
 128     BluetoothGattService* service = characteristic->GetService();
 129     remote_service_.id = service->GetIdentifier();
 130   }
 131 }
 132
 133 void BluetoothLowEnergyCharacteristicsFinder::ResetCallbacks() {
 134   success_callback_.Reset();
 135   error_callback_.Reset();
 136 }
 137
 138 }  // namespace proximity_auth