arc: bluetooth: Implement Gatt Server add/delete/start/stop service

components/arc/bluetooth/arc_bluetooth_bridge.cc

 // 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.
 
 #include "components/arc/bluetooth/arc_bluetooth_bridge.h"
 
 #include <fcntl.h>
 #include <stddef.h>
 
 #include <iomanip>
@@ skipping 35 matching lines @@
 using device::BluetoothLocalGattDescriptor;
 using device::BluetoothLocalGattService;
 using device::BluetoothRemoteGattCharacteristic;
 using device::BluetoothRemoteGattDescriptor;
 using device::BluetoothRemoteGattService;
 using device::BluetoothUUID;
 
 namespace {
 constexpr int32_t kMinBtleVersion = 1;
 constexpr int32_t kMinBtleNotifyVersion = 2;
+constexpr int32_t kMinGattServerVersion = 3;
 constexpr uint32_t kGattReadPermission =
     BluetoothGattCharacteristic::Permission::PERMISSION_READ |
     BluetoothGattCharacteristic::Permission::PERMISSION_READ_ENCRYPTED |
     BluetoothGattCharacteristic::Permission::
         PERMISSION_READ_ENCRYPTED_AUTHENTICATED;
 constexpr uint32_t kGattWritePermission =
     BluetoothGattCharacteristic::Permission::PERMISSION_WRITE |
     BluetoothGattCharacteristic::Permission::PERMISSION_WRITE_ENCRYPTED |
     BluetoothGattCharacteristic::Permission::
         PERMISSION_WRITE_ENCRYPTED_AUTHENTICATED;
+constexpr int32_t kInvalidGattAttributeHandle = -1;
 }  // namespace
 
 namespace arc {
 
 ArcBluetoothBridge::ArcBluetoothBridge(ArcBridgeService* bridge_service)
     : ArcService(bridge_service), binding_(this), weak_factory_(this) {
   if (BluetoothAdapterFactory::IsBluetoothAdapterAvailable()) {
     VLOG(1) << "registering bluetooth adapter";
     BluetoothAdapterFactory::GetAdapter(base::Bind(
         &ArcBluetoothBridge::OnAdapterInitialized, weak_factory_.GetWeakPtr()));
@@ skipping 784 matching lines @@
     mojom::BluetoothGattIDPtr desc_id) const {
   BluetoothRemoteGattCharacteristic* characteristic = FindGattCharacteristic(
       std::move(remote_addr), std::move(service_id), std::move(char_id));
   if (!characteristic)
     return nullptr;
 
   return FindGattObjectFromUuid<BluetoothRemoteGattDescriptor>(
       characteristic->GetDescriptors(), desc_id->uuid.To<BluetoothUUID>());
 }
 
+// Common callback function for Gatt operation that only need to report
+// Gatt status back to Android.
+void ArcBluetoothBridge::OnGattOperationDone(
+    const GattStatusCallback& callback) const {
+  callback.Run(mojom::BluetoothGattStatus::GATT_SUCCESS);
+}
+
+void ArcBluetoothBridge::OnGattOperationError(
+    const GattStatusCallback& callback,
+    BluetoothGattService::GattErrorCode error_code) const {
+  callback.Run(mojo::ConvertTo<mojom::BluetoothGattStatus>(error_code));
+}
+
 // Same callback for both ReadGattCharacteristic and ReadGattDescriptor
 void ArcBluetoothBridge::OnGattReadDone(
     const GattReadCallback& callback,
     const std::vector<uint8_t>& result) const {
   mojom::BluetoothGattValuePtr gattValue = mojom::BluetoothGattValue::New();
   gattValue->status = mojom::BluetoothGattStatus::GATT_SUCCESS;
   gattValue->value = mojo::Array<uint8_t>::From(result);
   callback.Run(std::move(gattValue));
 }
 
 void ArcBluetoothBridge::OnGattReadError(
     const GattReadCallback& callback,
     BluetoothGattService::GattErrorCode error_code) const {
   mojom::BluetoothGattValuePtr gattValue = mojom::BluetoothGattValue::New();
   gattValue->status = mojo::ConvertTo<mojom::BluetoothGattStatus>(error_code);
   gattValue->value = nullptr;
 
   callback.Run(std::move(gattValue));
 }
 
-// Same callback for both WriteGattCharacteristic and WriteGattDescriptor
-void ArcBluetoothBridge::OnGattWriteDone(
-    const GattWriteCallback& callback) const {
-  callback.Run(mojom::BluetoothGattStatus::GATT_SUCCESS);
-}
-
-void ArcBluetoothBridge::OnGattWriteError(
-    const GattWriteCallback& callback,
-    BluetoothGattService::GattErrorCode error_code) const {
-  callback.Run(mojo::ConvertTo<mojom::BluetoothGattStatus>(error_code));
-}
-
 void ArcBluetoothBridge::ReadGattCharacteristic(
     mojom::BluetoothAddressPtr remote_addr,
     mojom::BluetoothGattServiceIDPtr service_id,
     mojom::BluetoothGattIDPtr char_id,
     const ReadGattCharacteristicCallback& callback) {
   BluetoothRemoteGattCharacteristic* characteristic = FindGattCharacteristic(
       std::move(remote_addr), std::move(service_id), std::move(char_id));
   DCHECK(characteristic);
   DCHECK(characteristic->GetPermissions() & kGattReadPermission);
 
@@ skipping 10 matching lines @@
     mojom::BluetoothGattIDPtr char_id,
     mojom::BluetoothGattValuePtr value,
     const WriteGattCharacteristicCallback& callback) {
   BluetoothRemoteGattCharacteristic* characteristic = FindGattCharacteristic(
       std::move(remote_addr), std::move(service_id), std::move(char_id));
   DCHECK(characteristic);
   DCHECK(characteristic->GetPermissions() & kGattWritePermission);
 
   characteristic->WriteRemoteCharacteristic(
       value->value.To<std::vector<uint8_t>>(),
-      base::Bind(&ArcBluetoothBridge::OnGattWriteDone,
+      base::Bind(&ArcBluetoothBridge::OnGattOperationDone,
                  weak_factory_.GetWeakPtr(), callback),
-      base::Bind(&ArcBluetoothBridge::OnGattWriteError,
+      base::Bind(&ArcBluetoothBridge::OnGattOperationError,
                  weak_factory_.GetWeakPtr(), callback));
 }
 
 void ArcBluetoothBridge::ReadGattDescriptor(
     mojom::BluetoothAddressPtr remote_addr,
     mojom::BluetoothGattServiceIDPtr service_id,
     mojom::BluetoothGattIDPtr char_id,
     mojom::BluetoothGattIDPtr desc_id,
     const ReadGattDescriptorCallback& callback) {
   BluetoothRemoteGattDescriptor* descriptor =
@@ skipping 24 matching lines @@
 
   // To register / deregister GATT notification, we need to
   // 1) Write to CCC Descriptor to enable/disable the notification
   // 2) Ask BT hw to register / deregister the notification
   // The Chrome API groups both steps into one API, and does not support writing
   // directly to the CCC Descriptor. Therefore, until we fix
   // https://crbug.com/622832, we return successfully when we encounter this.
   // TODO(http://crbug.com/622832)
   if (descriptor->GetUUID() ==
       BluetoothGattDescriptor::ClientCharacteristicConfigurationUuid()) {
-    OnGattWriteDone(callback);
+    OnGattOperationDone(callback);
     return;
   }
 
   descriptor->WriteRemoteDescriptor(
       value->value.To<std::vector<uint8_t>>(),
-      base::Bind(&ArcBluetoothBridge::OnGattWriteDone,
+      base::Bind(&ArcBluetoothBridge::OnGattOperationDone,
                  weak_factory_.GetWeakPtr(), callback),
-      base::Bind(&ArcBluetoothBridge::OnGattWriteError,
+      base::Bind(&ArcBluetoothBridge::OnGattOperationError,
                  weak_factory_.GetWeakPtr(), callback));
 }
 
 void ArcBluetoothBridge::OnGattNotifyStartDone(
     const RegisterForGattNotificationCallback& callback,
     const std::string char_string_id,
     std::unique_ptr<BluetoothGattNotifySession> notify_session) {
   notification_session_[char_string_id] = std::move(notify_session);
   callback.Run(mojom::BluetoothGattStatus::GATT_SUCCESS);
 }
 
-void ArcBluetoothBridge::OnGattNotifyStartError(
-    const RegisterForGattNotificationCallback& callback,
-    BluetoothGattService::GattErrorCode error_code) const {
-  callback.Run(mojo::ConvertTo<mojom::BluetoothGattStatus>(error_code));
-}
-
-void ArcBluetoothBridge::OnGattNotifyStopDone(
-    const DeregisterForGattNotificationCallback& callback) const {
-  callback.Run(mojom::BluetoothGattStatus::GATT_SUCCESS);
-}
-
 void ArcBluetoothBridge::RegisterForGattNotification(
     mojom::BluetoothAddressPtr remote_addr,
     mojom::BluetoothGattServiceIDPtr service_id,
     mojom::BluetoothGattIDPtr char_id,
     const RegisterForGattNotificationCallback& callback) {
   BluetoothRemoteGattCharacteristic* characteristic = FindGattCharacteristic(
       std::move(remote_addr), std::move(service_id), std::move(char_id));
 
   if (!characteristic) {
     LOG(WARNING) << __func__ << " Characteristic is not existed.";
     return;
   }
 
   if (characteristic->IsNotifying()) {
     callback.Run(mojom::BluetoothGattStatus::GATT_SUCCESS);
     return;
   }
 
   characteristic->StartNotifySession(
       base::Bind(&ArcBluetoothBridge::OnGattNotifyStartDone,
                  weak_factory_.GetWeakPtr(), callback,
                  characteristic->GetIdentifier()),
-      base::Bind(&ArcBluetoothBridge::OnGattNotifyStartError,
+      base::Bind(&ArcBluetoothBridge::OnGattOperationError,
                  weak_factory_.GetWeakPtr(), callback));
 }
 
 void ArcBluetoothBridge::DeregisterForGattNotification(
     mojom::BluetoothAddressPtr remote_addr,
     mojom::BluetoothGattServiceIDPtr service_id,
     mojom::BluetoothGattIDPtr char_id,
     const DeregisterForGattNotificationCallback& callback) {
   BluetoothRemoteGattCharacteristic* characteristic = FindGattCharacteristic(
       std::move(remote_addr), std::move(service_id), std::move(char_id));
 
   if (!characteristic) {
     LOG(WARNING) << __func__ << " Characteristic is not existed.";
     return;
   }
 
   if (!characteristic->IsNotifying()) {
     callback.Run(mojom::BluetoothGattStatus::GATT_SUCCESS);
     return;
   }
 
   std::string char_id_str = characteristic->GetIdentifier();
   std::unique_ptr<BluetoothGattNotifySession> notify =
       std::move(notification_session_[char_id_str]);
   notification_session_.erase(char_id_str);
-  notify->Stop(base::Bind(&ArcBluetoothBridge::OnGattNotifyStopDone,
+  notify->Stop(base::Bind(&ArcBluetoothBridge::OnGattOperationDone,
                           weak_factory_.GetWeakPtr(), callback));
 }
 
 void ArcBluetoothBridge::ReadRemoteRssi(
     mojom::BluetoothAddressPtr remote_addr,
     const ReadRemoteRssiCallback& callback) {
   BluetoothDevice* device =
       bluetooth_adapter_->GetDevice(remote_addr->To<std::string>());
   int rssi = device->GetInquiryRSSI();
   callback.Run(rssi);
 }
 
+template <class T>
+int32_t ArcBluetoothBridge::CreateGattAttributeHandle(T* gatt_obj) {
+  if (!gatt_obj)
+    return kInvalidGattAttributeHandle;
+  std::string identifier = gatt_obj->GetIdentifier();
+  int32_t id = ConvertGattIdentifierToId(identifier);

[rkc, 2016/07/01 22:21:46]

This function won't work with IDs returned by gatt server functions. We use a
guid as the last part of the ID. You can always just have an incremental handle
count instead of trying to use the internal ID format (even for remote gatt
objects).

[puthik_chromium, 2016/07/14 19:01:47]

I added the incremental handle count.

+  DCHECK(gatt_identifier_.find(id) == gatt_identifier_.end());
+  gatt_identifier_[id] = identifier;
+  return id;
+}
+
 void ArcBluetoothBridge::AddService(mojom::BluetoothGattServiceIDPtr service_id,
                                     int32_t num_handles,
-                                    const AddServiceCallback& callback) {}
+                                    const AddServiceCallback& callback) {
+  base::WeakPtr<BluetoothLocalGattService> service =
+      BluetoothLocalGattService::Create(
+          bluetooth_adapter_.get(), service_id->id->uuid.To<BluetoothUUID>(),
+          service_id->is_primary, nullptr /*included_service */,
+          this /* delegate*/);
+  callback.Run(
+      CreateGattAttributeHandle<BluetoothLocalGattService>(service.get()));
+}
 
 void ArcBluetoothBridge::AddCharacteristic(
     int32_t service_handle,
     mojom::BluetoothUUIDPtr uuid,
     int32_t properties,
     int32_t permissions,
-    const AddCharacteristicCallback& callback) {}
+    const AddCharacteristicCallback& callback) {
+  base::WeakPtr<BluetoothLocalGattCharacteristic> characteristic =
+      BluetoothLocalGattCharacteristic::Create(
+          uuid.To<BluetoothUUID>(), properties, permissions,
+          bluetooth_adapter_->GetGattService(gatt_identifier_[service_handle]));
+  callback.Run(CreateGattAttributeHandle<BluetoothLocalGattCharacteristic>(
+      characteristic.get()));
+}
 
 void ArcBluetoothBridge::AddDescriptor(int32_t service_handle,
                                        mojom::BluetoothUUIDPtr uuid,
                                        int32_t permissions,
-                                       const AddDescriptorCallback& callback) {}
+                                       const AddDescriptorCallback& callback) {
+  // TODO(next patch version) Android send service handle not characteristic.

[rkc, 2016/07/01 22:21:45]

TODO(puthik)?

So this is because on Android, you first create a descriptor, then add it to a
characteristic. This is the opposite from how our API was designed. This will
require a bit of a hack to solve. Let's discuss this offline.

[puthik_chromium, 2016/07/14 19:01:47]

I add the descriptor to the last added characteristic and that seems to be
working correctly

[rkc, 2016/07/14 23:15:25]

Have you read through the Android code to verify this will always be the case?
If so, please add a detailed comment here explaining what the Android code does
and why we know that descriptors for characteristic will only be added after it.
Links to Android code would be super useful. As far as I can tell, the Android
code constructs a service 

Usually relying on current behavior is not a great way to write code but in this
case, since we don't actually have a characteristic ID at all, at any point, we
may not have an option.

I'd like to us to make sure that we have done the due diligence to verify that
this is always true :)

+  // That's not make sense.
+}
 
 void ArcBluetoothBridge::StartService(int32_t service_handle,
                                       int32_t transport,
-                                      const StartServiceCallback& callback) {}
+                                      const StartServiceCallback& callback) {
+  BluetoothLocalGattService* service =
+      bluetooth_adapter_->GetGattService(gatt_identifier_[service_handle]);
+  service->Register(base::Bind(&ArcBluetoothBridge::OnGattOperationDone,
+                               weak_factory_.GetWeakPtr(), callback),
+                    base::Bind(&ArcBluetoothBridge::OnGattOperationError,
+                               weak_factory_.GetWeakPtr(), callback));
+}
 
 void ArcBluetoothBridge::StopService(int32_t service_handle,
-                                     const StopServiceCallback& callback) {}
+                                     const StopServiceCallback& callback) {
+  BluetoothLocalGattService* service =
+      bluetooth_adapter_->GetGattService(gatt_identifier_[service_handle]);
+  service->Unregister(base::Bind(&ArcBluetoothBridge::OnGattOperationDone,
+                                 weak_factory_.GetWeakPtr(), callback),
+                      base::Bind(&ArcBluetoothBridge::OnGattOperationError,
+                                 weak_factory_.GetWeakPtr(), callback));
+}
 
 void ArcBluetoothBridge::DeleteService(int32_t service_handle,
-                                       const DeleteServiceCallback& callback) {}
+                                       const DeleteServiceCallback& callback) {
+  BluetoothLocalGattService* service =
+      bluetooth_adapter_->GetGattService(gatt_identifier_[service_handle]);
+  service->Delete();
+  gatt_identifier_.erase(service_handle);
+  OnGattOperationDone(callback);
+}
 
 void ArcBluetoothBridge::SendIndication(
     int32_t attribute_handle,
     mojom::BluetoothAddressPtr address,
     int32_t confirm,
     mojo::Array<uint8_t> value,
     const SendIndicationCallback& callback) {}
 
 void ArcBluetoothBridge::SendResponse(int32_t trans_id,
                                       int32_t status,
@@ skipping 331 matching lines @@
     int32_t version_need) const {
   int32_t version = arc_bridge_service()->bluetooth_version();
   if (version >= version_need)
     return true;
   LOG(WARNING) << "Bluetooth instance is too old (version " << version
                << ") need version " << version_need;
   return false;
 }
 
 }  // namespace arc