bluetooth: Subscribe to notifications

content/browser/bluetooth/bluetooth_dispatcher_host.cc

Index: content/browser/bluetooth/bluetooth_dispatcher_host.cc
diff --git a/content/browser/bluetooth/bluetooth_dispatcher_host.cc b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
index 75556c0b319d3f4b7bc0656813429e7fd04545a1..008eba24f246737faa3815d2b165730079e10f3d 100644
--- a/content/browser/bluetooth/bluetooth_dispatcher_host.cc
+++ b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
@@ -199,6 +199,8 @@ bool BluetoothDispatcherHost::OnMessageReceived(const IPC::Message& message) {
   IPC_MESSAGE_HANDLER(BluetoothHostMsg_GetCharacteristic, OnGetCharacteristic)
   IPC_MESSAGE_HANDLER(BluetoothHostMsg_ReadValue, OnReadValue)
   IPC_MESSAGE_HANDLER(BluetoothHostMsg_WriteValue, OnWriteValue)
+  IPC_MESSAGE_HANDLER(BluetoothHostMsg_StartNotifications, OnStartNotifications)
+  IPC_MESSAGE_HANDLER(BluetoothHostMsg_StopNotifications, OnStopNotifications)
   IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -347,6 +349,15 @@ void BluetoothDispatcherHost::DeviceRemoved(device::BluetoothAdapter* adapter,
   }
 }
 
+void BluetoothDispatcherHost::GattCharacteristicValueChanged(
+    device::BluetoothAdapter* adapter,
+    device::BluetoothGattCharacteristic* characteristic,
+    const std::vector<uint8>& value) {
+  // TODO(ortuno): Notify renderer the characteristic changed.
+  // http://crbug.com/529560
+  VLOG(1) << "Characteristic updated.";
+}
+
 void BluetoothDispatcherHost::OnRequestDevice(
     int thread_id,
     int request_id,
@@ -694,6 +705,92 @@ void BluetoothDispatcherHost::OnWriteValue(
                  weak_ptr_factory_.GetWeakPtr(), thread_id, request_id));
 }
 
+void BluetoothDispatcherHost::OnStartNotifications(
+    int thread_id,
+    int request_id,
+    const std::string& characteristic_instance_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  RecordWebBluetoothFunctionCall(
+      UMAWebBluetoothFunction::CHARACTERISTIC_START_NOTIFICATIONS);
+
+  // Check if already subscribed to notifications.
+  auto notify_session_iter =
+      characteristic_id_to_notify_session_.find(characteristic_instance_id);
+  if (notify_session_iter != characteristic_id_to_notify_session_.end()) {
+    Send(new BluetoothMsg_StartNotificationsSuccess(thread_id, request_id));

[Jeffrey Yasskin, 2015/09/25 23:03:19]

This is vulnerable to races if a second BluetoothHostMsg_StartNotifications
comes in while the first is still registering. I assume that's handled in two
ways: 1) BluetoothDispatcher won't send 2 Start() requests concurrently (and we
don't support multiple thread_ids yet), and 2) OnStartNotifySessionSuccess()
will destroy its notification session if it can't insert it.

Comment this, please. If I've missed a real problem that'll require code to fix,
but it won't make the API unusable, probably file a bug and add a TODO rather
than fixing it in this CL.

[ortuno, 2015/09/29 22:47:36]

This code was wrote before I implemented the queues in Dispatcher.
BluetoothDispatcher should never send a request for a characteristic already
subscribed to notifications. Added a DCHECK.

+    return;
+  }
+
+  // TODO(ortuno): Check if notify/indicate bit is set.

[Jeffrey Yasskin, 2015/09/25 23:03:19]

Add a blank line below this, since it's not connected to looking up the
characteristic.

[ortuno, 2015/09/29 22:47:36]

Done.

+  auto characteristic_iter =
+      characteristic_to_service_.find(characteristic_instance_id);
+  // A characteristic_instance_id not in the map implies a hostile renderer
+  // because a renderer obtains the characteristic id from this class and
+  // it will be added to the map at that time.
+  if (characteristic_iter == characteristic_to_service_.end()) {
+    // Kill the renderer
+    bad_message::ReceivedBadMessage(this,
+                                    bad_message::BDH_INVALID_CHARACTERISTIC_ID);
+    return;
+  }
+
+  const std::string& service_instance_id = characteristic_iter->second;
+  auto device_iter = service_to_device_.find(service_instance_id);
+  CHECK(device_iter != service_to_device_.end());
+
+  device::BluetoothDevice* device =
+      adapter_->GetDevice(device_iter->second /* device_instance_id */);
+  if (device == nullptr) {  // See "NETWORK_ERROR Note" above.
+    RecordStartNotificationsOutcome(UMAGATTOperationOutcome::NO_DEVICE);
+    Send(new BluetoothMsg_StartNotificationsError(
+        thread_id, request_id, WebBluetoothError::DeviceNoLongerInRange));
+    return;
+  }
+
+  BluetoothGattService* service = device->GetGattService(service_instance_id);
+  if (service == nullptr) {
+    RecordStartNotificationsOutcome(UMAGATTOperationOutcome::NO_SERVICE);
+    Send(new BluetoothMsg_StartNotificationsError(
+        thread_id, request_id, WebBluetoothError::ServiceNoLongerExists));
+    return;
+  }
+
+  BluetoothGattCharacteristic* characteristic =
+      service->GetCharacteristic(characteristic_instance_id);
+  if (characteristic == nullptr) {
+    RecordStartNotificationsOutcome(UMAGATTOperationOutcome::NO_CHARACTERISTIC);
+    Send(new BluetoothMsg_StartNotificationsError(
+        thread_id, request_id,
+        WebBluetoothError::CharacteristicNoLongerExists));
+    return;
+  }
+
+  characteristic->StartNotifySession(
+      base::Bind(&BluetoothDispatcherHost::OnStartNotifySessionSuccess,
+                 weak_ptr_factory_.GetWeakPtr(), thread_id, request_id),
+      base::Bind(&BluetoothDispatcherHost::OnStartNotifySessionFailed,
+                 weak_ptr_factory_.GetWeakPtr(), thread_id, request_id));
+}
+void BluetoothDispatcherHost::OnStopNotifications(
+    int thread_id,
+    int request_id,
+    const std::string& characteristic_instance_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  RecordWebBluetoothFunctionCall(
+      UMAWebBluetoothFunction::CHARACTERISTIC_STOP_NOTIFICATIONS);
+
+  auto notify_session_iter =
+      characteristic_id_to_notify_session_.find(characteristic_instance_id);
+  if (notify_session_iter == characteristic_id_to_notify_session_.end()) {
+    Send(new BluetoothMsg_StopNotificationsSuccess(thread_id, request_id));
+    return;
+  }
+  notify_session_iter->second->Stop(
+      base::Bind(&BluetoothDispatcherHost::OnStopNotifySession,
+                 weak_ptr_factory_.GetWeakPtr(), thread_id, request_id,
+                 characteristic_instance_id));
+}
+
 void BluetoothDispatcherHost::OnDiscoverySessionStarted(
     int chooser_id,
     scoped_ptr<device::BluetoothDiscoverySession> discovery_session) {
@@ -923,6 +1020,33 @@ void BluetoothDispatcherHost::OnWriteValueFailed(
       TranslateGATTError(error_code, UMAGATTOperation::CHARACTERISTIC_WRITE)));
 }
 
+void BluetoothDispatcherHost::OnStartNotifySessionSuccess(
+    int thread_id,
+    int request_id,
+    scoped_ptr<device::BluetoothGattNotifySession> notify_session) {
+  characteristic_id_to_notify_session_.insert(
+      notify_session->GetCharacteristicIdentifier(), notify_session.Pass());
+  Send(new BluetoothMsg_StartNotificationsSuccess(thread_id, request_id));

[Jeffrey Yasskin, 2015/09/25 23:03:19]

Call RecordStartNotificationsOutcome() here, right?

[ortuno, 2015/09/29 22:47:36]

Done.

+}
+
+void BluetoothDispatcherHost::OnStartNotifySessionFailed(
+    int thread_id,
+    int request_id,
+    device::BluetoothGattService::GattErrorCode error_code) {
+  // TranslateGATTError calls RecordGATTOperationOutcome.
+  Send(new BluetoothMsg_StartNotificationsError(
+      thread_id, request_id,
+      TranslateGATTError(error_code, UMAGATTOperation::START_NOTIFICATIONS)));
+}
+
+void BluetoothDispatcherHost::OnStopNotifySession(
+    int thread_id,
+    int request_id,
+    const std::string& characteristic_instance_id) {
+  characteristic_id_to_notify_session_.erase(characteristic_instance_id);
+  Send(new BluetoothMsg_StopNotificationsSuccess(thread_id, request_id));
+}
+
 void BluetoothDispatcherHost::ShowBluetoothOverviewLink() {
   NOTIMPLEMENTED();
 }