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>
 #include <string>
+#include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/bluetooth/bluetooth_type_converters.h"
@@ skipping 20 matching lines @@
 using device::BluetoothLocalGattService;
 using device::BluetoothRemoteGattCharacteristic;
 using device::BluetoothRemoteGattDescriptor;
 using device::BluetoothRemoteGattService;
 using device::BluetoothTransport;
 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 672 matching lines @@
 
 // Example of identifier: /org/bluez/hci0/dev_E0_CF_65_8C_86_1A/service001a
 // We want to convert last digit of the identifier to int in base 16
 int ArcBluetoothBridge::ConvertGattIdentifierToId(
     const std::string identifier) const {
   return std::stoi(identifier.substr(identifier.size() - 4), nullptr, 16);
 }
 
 // Create GattDBElement and fill in common data for
 // Gatt Service/Characteristic/Descriptor.
-template <class T>
+template <class RemoteGattObjectT>
 mojom::BluetoothGattDBElementPtr ArcBluetoothBridge::CreateGattDBElement(
     const mojom::BluetoothGattDBAttributeType type,
-    const T* gattObject) const {
+    const RemoteGattObjectT* gattObject) const {
   mojom::BluetoothGattDBElementPtr element =
       mojom::BluetoothGattDBElement::New();
   element->type = type;
   element->uuid = mojom::BluetoothUUID::From(gattObject->GetUUID());
   element->id = element->attribute_handle = element->start_handle =
       element->end_handle =
           ConvertGattIdentifierToId(gattObject->GetIdentifier());
   element->properties = 0;
   return element;
 }
@@ skipping 38 matching lines @@
             descriptor));
       }
     }
   }
 
   arc_bridge_service()->bluetooth()->instance()->OnGetGattDB(
       std::move(remote_addr), std::move(db));
 }
 
 // Find Gatt Service/Characteristic/Descriptor from std::vector from UUID.
-template <class T>
-T* ArcBluetoothBridge::FindGattObjectFromUuid(
-    const std::vector<T*> gatt_objs,
+template <class RemoteGattObjectT>
+RemoteGattObjectT* ArcBluetoothBridge::FindGattObjectFromUuid(
+    const std::vector<RemoteGattObjectT*> gatt_objs,
     const device::BluetoothUUID uuid) const {
-  auto it = std::find_if(gatt_objs.begin(), gatt_objs.end(),
-                         [&](T* obj) { return obj->GetUUID() == uuid; });
+  auto it = std::find_if(
+      gatt_objs.begin(), gatt_objs.end(),
+      [&](RemoteGattObjectT* obj) { return obj->GetUUID() == uuid; });
   if (it == gatt_objs.end())
     return nullptr;
   return *it;
 }
 
 BluetoothRemoteGattCharacteristic* ArcBluetoothBridge::FindGattCharacteristic(
     mojom::BluetoothAddressPtr remote_addr,
     mojom::BluetoothGattServiceIDPtr service_id,
     mojom::BluetoothGattIDPtr char_id) const {
   DCHECK(remote_addr);
@@ skipping 22 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

[palmer, 2016/07/16 00:45:13]

Comment style:

Common callback for GATT operations that only need to report GATT status back to
Android.

[puthik_chromium, 2016/07/18 21:30:13]

Done.

+// 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 LocalGattObjectT>
+int32_t ArcBluetoothBridge::CreateGattAttributeHandle(
+    LocalGattObjectT* gatt_obj) {
+  if (!gatt_obj)
+    return kInvalidGattAttributeHandle;
+  gatt_server_obj_handle++;
+  std::string identifier = gatt_obj->GetIdentifier();
+  gatt_identifier_[gatt_server_obj_handle] = identifier;

[palmer, 2016/07/16 00:45:13]

Nit: You could save a line and write:

  gatt_identifier_[gatt_server_obj_handle] = gatt_obj->GetIdentifier();

[puthik_chromium, 2016/07/18 21:30:13]

We will reuse |identifier| in the next patch when introducing the map in the
reverse direction for RequestRead / RequestWrite.

+  return gatt_server_obj_handle;
+}
+
 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]));
+  int32_t characteristic_handle =
+      CreateGattAttributeHandle<BluetoothLocalGattCharacteristic>(
+          characteristic.get());
+  last_characteristic_[service_handle] = characteristic_handle;
+  callback.Run(characteristic_handle);
+}
 
 void ArcBluetoothBridge::AddDescriptor(int32_t service_handle,
                                        mojom::BluetoothUUIDPtr uuid,
                                        int32_t permissions,
-                                       const AddDescriptorCallback& callback) {}
+                                       const AddDescriptorCallback& callback) {
+  // Chrome automatically add CCC Descriptor to a characteristic when needed.

[palmer, 2016/07/16 00:45:13]

Nit: Check your grammar and punctuation in comments generally. E.g.:

Chrome automatically adds a CCC Descriptor to a characteristic when needed. We
will generate a bogus handle for Android.

[puthik_chromium, 2016/07/18 21:30:12]

Done.

+  // So we will just generate bogus handle for android.
+  if (uuid.To<BluetoothUUID>() ==
+      BluetoothGattDescriptor::ClientCharacteristicConfigurationUuid()) {
+    gatt_server_obj_handle++;
+    callback.Run(gatt_server_obj_handle);
+    return;
+  }
+
+  BluetoothLocalGattService* service =
+      bluetooth_adapter_->GetGattService(gatt_identifier_[service_handle]);
+  // Since Android API does not give information which characteristic is the

[palmer, 2016/07/16 00:45:13]

Comment style:

Since the Android API does not give information about which characteristic is
the parent of the new descriptor, we assume that it would be the last
characteristic that was added to the given service. This matches the ... [fill
in the rest]

[puthik_chromium, 2016/07/18 21:30:12]

I accidentally deleted the last line of comment.
Done.

+  // parent of the new descriptor. We will just assume that it would be the
+  // last characteristic that was added to the given service. This matches the

[rkc, 2016/07/16 00:37:29]

Incomplete comment?
Please add the Android source link here to show that this is how Android will
always call AddDescriptor.

[puthik_chromium, 2016/07/18 21:30:12]

I accidentally deleted the last line of comment.
Done.

+  BluetoothLocalGattCharacteristic* characteristic = service->GetCharacteristic(
+      gatt_identifier_[last_characteristic_[service_handle]]);
+
+  base::WeakPtr<BluetoothLocalGattDescriptor> descriptor =
+      BluetoothLocalGattDescriptor::Create(uuid.To<BluetoothUUID>(),
+                                           permissions, characteristic);
+  callback.Run(CreateGattAttributeHandle<BluetoothLocalGattDescriptor>(
+      descriptor.get()));
+}
 
 void ArcBluetoothBridge::StartService(int32_t service_handle,
-                                      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,
     bool confirm,
     mojo::Array<uint8_t> value,
     const SendIndicationCallback& callback) {}
 
 void ArcBluetoothBridge::SendResponse(int32_t trans_id,
                                       int32_t status,
@@ skipping 331 matching lines @@
     uint32_t version_need) const {
   uint32_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