arc: bluetooth: Use UUID 16 bits in advertising data

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 <bluetooth/bluetooth.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <sys/socket.h>
@@ skipping 159 matching lines @@
   if (status == arc::mojom::BluetoothGattStatus::GATT_SUCCESS)
     success_callback.Run();
   else
     error_callback.Run();
 }
 
 bool IsGattOffsetValid(int offset) {
   return 0 <= offset && offset < kMaxGattAttributeLength;
 }
 
+// This is needed because Android only support UUID 16 bits in advertising data.
+uint16_t GetUUID16(const BluetoothUUID& uuid) {
+  // Convert xxxxyyyy-xxxx-xxxx-xxxx-xxxxxxxxxxxx to int16 yyyy
+  return std::stoi(uuid.canonical_value().substr(4, 4), nullptr, 16);
+}
+
 }  // 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 1356 matching lines @@
     btp->set_local_le_features(std::move(le_features));
     properties.push_back(std::move(btp));
   }
 
   return properties;
 }
 
 // Android support 5 types of Advertising Data.
 // However Chrome didn't expose AdvertiseFlag and ManufacturerData.
 // So we will only expose local_name, service_uuids and service_data.
+// Note that we need to use UUID 16 bits because Android does not support
+// UUID 128 bits.
 // TODO(crbug.com/618442) Make Chrome expose missing data.
 mojo::Array<mojom::BluetoothAdvertisingDataPtr>
 ArcBluetoothBridge::GetAdvertisingData(BluetoothDevice* device) const {
   mojo::Array<mojom::BluetoothAdvertisingDataPtr> advertising_data;
 
   // LocalName
   mojom::BluetoothAdvertisingDataPtr local_name =
       mojom::BluetoothAdvertisingData::New();
   local_name->set_local_name(device->GetName() ? device->GetName().value()
                                                : nullptr);
   advertising_data.push_back(std::move(local_name));
 
   // ServiceUuid
   BluetoothDevice::UUIDList uuid_list = device->GetUUIDs();
   if (uuid_list.size() > 0) {
-    mojom::BluetoothAdvertisingDataPtr service_uuids =
+    mojom::BluetoothAdvertisingDataPtr service_uuids_16 =
         mojom::BluetoothAdvertisingData::New();
-    service_uuids->set_service_uuids(
-        mojo::Array<mojom::BluetoothUUIDPtr>::From(uuid_list));
-    advertising_data.push_back(std::move(service_uuids));
+    mojo::Array<uint16_t> uuid16s;
+    for (auto& uuid : uuid_list) {
+      uuid16s.push_back(GetUUID16(uuid));
+    }
+    service_uuids_16->set_service_uuids_16(std::move(uuid16s));
+    advertising_data.push_back(std::move(service_uuids_16));
   }
 
   // Service data
   for (auto& uuid : device->GetServiceDataUUIDs()) {
     base::BinaryValue* data = device->GetServiceData(uuid);
     if (data->GetSize() == 0)
       continue;
     std::string data_str;
     if (!data->GetAsString(&data_str))
       continue;
 
     mojom::BluetoothAdvertisingDataPtr service_data_element =
         mojom::BluetoothAdvertisingData::New();
     mojom::BluetoothServiceDataPtr service_data =
         mojom::BluetoothServiceData::New();
 
-    std::string uuid_str = uuid.canonical_value();
-    // Convert xxxxyyyy-xxxx-xxxx-xxxx-xxxxxxxxxxxx to int16 yyyy
-    service_data->uuid_16bit = std::stoi(uuid_str.substr(4, 4), nullptr, 16);
+    service_data->uuid_16bit = GetUUID16(uuid);
     for (auto& c : data_str) {
       service_data->data.push_back(c);
     }
     service_data_element->set_service_data(std::move(service_data));
     advertising_data.push_back(std::move(service_data_element));
   }
 
   return advertising_data;
 }
 
@@ skipping 81 matching lines @@
   LOG(WARNING) << "Bluetooth instance is too old (version " << version
                << ") need version " << version_need;
   return false;
 }
 
 bool ArcBluetoothBridge::CalledOnValidThread() {
   return thread_checker_.CalledOnValidThread();
 }
 
 }  // namespace arc