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 c1a2395c4f2bb918ab826e0a4242535217dbd999..bc6674b44d6b7601534893311c29cc49ab5376c3 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;
@@ -315,6 +317,15 @@ 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.";
+}
+
 static scoped_ptr<device::BluetoothDiscoveryFilter> ComputeScanFilter(
     const std::vector<BluetoothScanFilter>& filters) {
   std::set<BluetoothUUID> services;
@@ -685,6 +696,97 @@ 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));
+    return;
+  }
+
+  // TODO(ortuno): Check if notify/indicate bit is set.
+
+  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(

[Jeffrey Yasskin, 2015/09/12 02:36:05]

If two different frames in the same process register for notifications on the
same characteristic, and then one of them unregisters, I believe this will stop
notifications for both. We need to somehow record which execution contexts are
actively watching.

[Jeffrey Yasskin, 2015/09/12 02:50:22]

esprehn says we should make something on the renderer side an ActiveDOMObject,
and refcount how many of those are keeping active notification sessions. Ojan
warns that ActiveDOMObject is a wonky API.

[ortuno, 2015/09/13 18:35:59]

I thought about that. I couldn't find any examples about two frames sharing the
same process, except for iframes but I thought we were not supporting bluetooth
inside iframes http://crbug.com/518042
Hmm yeah I didn't make BluetoothCharacteristic an ActiveDOMObject because I was
trying to go for the smallest CL to unlock the rolling spider demo. The CL that
adds the events will make our object ActiveDOMObject.

+      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) {
@@ -914,6 +1016,33 @@ 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));
+}
+
+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();
 }