Initial implementation of BluetoothServerSocket

PiperOrigin-RevId: 390461649
2026-09-15 07:06:11 -04:00 · 2021-08-12 14:33:26 -07:00
parent 512ba2af43
commit 07d33cfa9e
6 changed files with 300 additions and 63 deletions
@@ -14,18 +14,23 @@

 #include "platform/impl/windows/bluetooth_classic_medium.h"

+#include <codecvt>
+#include <locale>
+#include <string>
+
+#include "platform/base/cancellation_flag.h"
+#include "platform/base/cancellation_flag_listener.h"
+#include "platform/base/exception.h"
+#include "platform/impl/windows/bluetooth_classic_device.h"
+#include "platform/impl/windows/bluetooth_classic_server_socket.h"
+#include "platform/impl/windows/bluetooth_classic_socket.h"
 #include "platform/impl/windows/generated/winrt/Windows.Devices.Bluetooth.Rfcomm.h"
 #include "platform/impl/windows/generated/winrt/Windows.Devices.Bluetooth.h"
 #include "platform/impl/windows/generated/winrt/Windows.Devices.Enumeration.h"
 #include "platform/impl/windows/generated/winrt/Windows.Foundation.Collections.h"
 #include "platform/impl/windows/generated/winrt/base.h"
-
-#include "platform/base/exception.h"
-#include "platform/impl/windows/bluetooth_classic_device.h"
-#include "platform/impl/windows/bluetooth_classic_socket.h"
+#include "platform/impl/windows/utils.h"
 #include "platform/public/logging.h"
-#include "platform/base/cancellation_flag.h"
-#include "platform/base/cancellation_flag_listener.h"

 namespace location {
 namespace nearby {
@@ -34,32 +39,7 @@ namespace windows {
 BluetoothClassicMedium::BluetoothClassicMedium() {
  InitializeCriticalSection(&critical_section_);

-  // create watcher
-  device_watcher_ = DeviceInformation::CreateWatcher(
-      BLUETOOTH_SELECTOR, nullptr, DeviceInformationKind::AssociationEndpoint);
-
-  // An app must subscribe to all of the added, removed, and updated events to
-  // be notified when there are device additions, removals or updates. If an app
-  // handles only the added event, it will not receive an update if a device is
-  // added to the system after the initial device enumeration completes.
-  // register event handlers before starting the watcher
-  //
-  //  Event that is raised when a device is added to the collection enumerated
-  //  by the DeviceWatcher.
-  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher.added?view=winrt-20348
-  device_watcher_.Added({this, &BluetoothClassicMedium::DeviceWatcher_Added});
-
-  // Event that is raised when a device is updated in the collection of
-  // enumerated devices.
-  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher.updated?view=winrt-20348
-  device_watcher_.Updated(
-      {this, &BluetoothClassicMedium::DeviceWatcher_Updated});
-
-  // Event that is raised when a device is removed from the collection of
-  // enumerated devices.
-  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher.removed?view=winrt-20348
-  device_watcher_.Removed(
-      {this, &BluetoothClassicMedium::DeviceWatcher_Removed});
+  InitializeDeviceWatcher();
 }

 BluetoothClassicMedium::~BluetoothClassicMedium() {}
@@ -99,6 +79,37 @@ bool BluetoothClassicMedium::StopDiscovery() {
  return result;
 }

+void BluetoothClassicMedium::InitializeDeviceWatcher() {
+  // create watcher
+  device_watcher_ = DeviceInformation::CreateWatcher(
+      BLUETOOTH_SELECTOR,                           // aqsFilter
+      nullptr,                                      // additionalProperties
+      DeviceInformationKind::AssociationEndpoint);  // kind
+
+  // An app must subscribe to all of the added, removed, and updated events to
+  // be notified when there are device additions, removals or updates. If an app
+  // handles only the added event, it will not receive an update if a device is
+  // added to the system after the initial device enumeration completes.
+  // register event handlers before starting the watcher
+  //
+  //  Event that is raised when a device is added to the collection enumerated
+  //  by the DeviceWatcher.
+  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher.added?view=winrt-20348
+  device_watcher_.Added({this, &BluetoothClassicMedium::DeviceWatcher_Added});
+
+  // Event that is raised when a device is updated in the collection of
+  // enumerated devices.
+  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher.updated?view=winrt-20348
+  device_watcher_.Updated(
+      {this, &BluetoothClassicMedium::DeviceWatcher_Updated});
+
+  // Event that is raised when a device is removed from the collection of
+  // enumerated devices.
+  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher.removed?view=winrt-20348
+  device_watcher_.Removed(
+      {this, &BluetoothClassicMedium::DeviceWatcher_Removed});
+}
+
 std::unique_ptr<api::BluetoothSocket> BluetoothClassicMedium::ConnectToService(
    api::BluetoothDevice& remote_device, const std::string& service_uuid,
    CancellationFlag* cancellation_flag) {
@@ -141,8 +152,7 @@ std::unique_ptr<api::BluetoothSocket> BluetoothClassicMedium::ConnectToService(

  location::nearby::CancellationFlagListener cancellationFlagListener(
      cancellation_flag,
-      [&rfcommSocket]() { rfcommSocket.get()->CancelIOAsync().get();
-    });
+      [&rfcommSocket]() { rfcommSocket.get()->CancelIOAsync().get(); });

  try {
    rfcommSocket
@@ -209,16 +219,16 @@ bool BluetoothClassicMedium::CheckSdp(RfcommDeviceService requestedService) {
  // device that actually supports the Bluetooth Rfcomm Service
  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.bluetooth.rfcomm.rfcommdeviceservice.getsdprawattributesasync?view=winrt-20348
  auto attributes = /*await*/ requestedService.GetSdpRawAttributesAsync();
-  if (!attributes.get().HasKey(SdpServiceNameAttributeId)) {
+  if (!attributes.get().HasKey(Constants::SdpServiceNameAttributeId)) {
    return false;
  }

  auto attributeReader = DataReader::FromBuffer(
-      attributes.get().Lookup(SdpServiceNameAttributeId));
+      attributes.get().Lookup(Constants::SdpServiceNameAttributeId));

  auto attributeType = attributeReader.ReadByte();

-  if (attributeType != SdpServiceNameAttributeType) {
+  if (attributeType != Constants::SdpServiceNameAttributeType) {
    return false;
  }

@@ -237,7 +247,20 @@ bool BluetoothClassicMedium::CheckSdp(RfcommDeviceService requestedService) {
 std::unique_ptr<api::BluetoothServerSocket>
 BluetoothClassicMedium::ListenForService(const std::string& service_name,
                                         const std::string& service_uuid) {
-  return nullptr;
+  if (service_uuid.empty()) {
+    return nullptr;
+  }
+
+  if (service_name.empty()) {
+    return nullptr;
+  }
+
+  auto bluetooth_server_socket =
+      std::make_unique<location::nearby::windows::BluetoothServerSocket>();
+
+  bluetooth_server_socket->StartListening(service_name, service_uuid);
+
+  return std::move(bluetooth_server_socket);
 }

 // TODO(b/184975123): replace with real implementation.
@@ -301,12 +324,12 @@ winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Added(

                devices_by_id_[deviceInfo.Id()] = std::move(bluetoothDevice);

-                LeaveCriticalSection(&critical_section_);
-
                if (discovery_callback_.device_discovered_cb != nullptr) {
                  discovery_callback_.device_discovered_cb(
                      *devices_by_id_[deviceInfo.Id()]);
                }
+
+                LeaveCriticalSection(&critical_section_);
              });
    }
  }
@@ -326,6 +349,8 @@ winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Updated(
 winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Removed(
    DeviceWatcher sender, DeviceInformationUpdate deviceInfo) {
  if (IsWatcherStarted()) {
+    EnterCriticalSection(&critical_section_);
+
    if (discovery_callback_.device_lost_cb != nullptr) {
      discovery_callback_.device_lost_cb(*devices_by_id_[deviceInfo.Id()]);
    }
@@ -333,6 +358,8 @@ winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Removed(
    devices_by_id_.erase(deviceInfo.Id());
  }

+  LeaveCriticalSection(&critical_section_);
+
  return winrt::fire_and_forget();
 }

@@ -18,8 +18,12 @@
 #include <Windows.h>
 #include <stdio.h>

+#include "platform/api/bluetooth_classic.h"
 #include "platform/impl/windows/bluetooth_classic_device.h"
+#include "platform/impl/windows/bluetooth_classic_server_socket.h"
+#include "platform/impl/windows/bluetooth_classic_socket.h"
 #include "platform/impl/windows/generated/winrt/Windows.Devices.Enumeration.h"
+#include "platform/impl/windows/generated/winrt/Windows.Networking.Sockets.h"
 #include "platform/impl/windows/generated/winrt/base.h"

 namespace location {
@@ -69,6 +73,10 @@ using winrt::Windows::Devices::Bluetooth::Rfcomm::RfcommServiceId;
 //  https://docs.microsoft.com/en-us/uwp/api/windows.storage.streams.datareader?view=winrt-20348
 using winrt::Windows::Storage::Streams::DataReader;

+// Writes data to an output stream.
+// https://docs.microsoft.com/en-us/uwp/api/windows.storage.streams.datawriter?view=winrt-20348
+using winrt::Windows::Storage::Streams::DataWriter;
+
 // Bluetooth protocol ID = \"{e0cbf06c-cd8b-4647-bb8a-263b43f0f974}\"
 // https://docs.microsoft.com/en-us/windows/uwp/devices-sensors/aep-service-class-ids
 #define BLUETOOTH_SELECTOR \
@@ -80,7 +88,6 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
 public:
  explicit BluetoothClassicMedium();

-  // TODO(b/184975123): replace with real implementation.
  ~BluetoothClassicMedium() override;

  // https://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#startDiscovery()
@@ -91,7 +98,6 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
  // Returns true once discovery is well and truly stopped; after this returns,
  // there must be no more invocations of the DiscoveryCallback passed in to
  // StartDiscovery().
-  // TODO(b/184975123): replace with real implementation.
  bool StopDiscovery() override;

  // A combination of
@@ -120,7 +126,6 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
  // UUID.
  //
  //  Returns nullptr error.
-  // TODO(b/184975123): replace with real implementation.
  std::unique_ptr<api::BluetoothServerSocket> ListenForService(
      const std::string& service_name,
      const std::string& service_uuid) override;
@@ -134,6 +139,7 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
  bool StopScanning();
  bool IsWatcherStarted();
  bool IsWatcherRunning();
+  void InitializeDeviceWatcher();

  // This is for a coroutine whose return type is winrt::fire_and_forget, which
  // handles async operations which don't have any dependencies.
@@ -151,27 +157,17 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
  bool HaveAccess(winrt::hstring deviceId);

  // Get the service requested
-  winrt::Windows::Devices::Bluetooth::Rfcomm::RfcommDeviceService
-  GetRequestedService(location::nearby::windows::BluetoothDevice* device,
-                      winrt::guid service);
+  RfcommDeviceService GetRequestedService(BluetoothDevice* device,
+                                          winrt::guid service);

  // Check to see that the device actually handles the requested service
-  bool CheckSdp(winrt::Windows::Devices::Bluetooth::Rfcomm::RfcommDeviceService
-                    requestedService);
+  bool CheckSdp(RfcommDeviceService requestedService);

  BluetoothClassicMedium::DiscoveryCallback discovery_callback_;

  DeviceWatcher device_watcher_ = nullptr;

-  // The Id of the Service Name SDP attribute
-  const uint16 SdpServiceNameAttributeId = 0x100;
-
-  // The SDP Type of the Service Name SDP attribute.
-  // The first byte in the SDP Attribute encodes the SDP Attribute Type as
-  // follows :
-  //    -  the Attribute Type size in the least significant 3 bits,
-  //    -  the SDP Attribute Type value in the most significant 5 bits.
-  const char SdpServiceNameAttributeType = (4 << 3) | 5;
+  std::unique_ptr<BluetoothSocket> bluetooth_socket_;

  // hstring is the only type of string winrt understands.
  // https://docs.microsoft.com/en-us/uwp/cpp-ref-for-winrt/hstring
@@ -14,9 +14,22 @@

 #include "platform/impl/windows/bluetooth_classic_server_socket.h"

+#include <codecvt>
+#include <locale>
+#include <string>
+
+#include "platform/impl/windows/bluetooth_classic_socket.h"
+#include "platform/impl/windows/generated/winrt/Windows.Foundation.Collections.h"
+#include "platform/impl/windows/utils.h"
+#include "platform/public/logging.h"
+
 namespace location {
 namespace nearby {
 namespace windows {
+BluetoothServerSocket::BluetoothServerSocket() {
+  InitializeCriticalSection(&critical_section_);
+}
+
 BluetoothServerSocket::~BluetoothServerSocket() {}

 // https://developer.android.com/reference/android/bluetooth/BluetoothServerSocket.html#accept()
@@ -27,17 +40,135 @@ BluetoothServerSocket::~BluetoothServerSocket() {}
 // On success, returns connected socket, ready to exchange data.
 // Returns nullptr on error.
 // Once error is reported, it is permanent, and ServerSocket has to be closed.
-// TODO(b/184975123): replace with real implementation.
 std::unique_ptr<api::BluetoothSocket> BluetoothServerSocket::Accept() {
+  while (bluetooth_sockets_.empty() && !closed_) {
+    Sleep(1000);
+  }
+
+  EnterCriticalSection(&critical_section_);
+  if (!closed_) {
+    std::unique_ptr<BluetoothSocket> bluetoothSocket =
+        std::move(bluetooth_sockets_.front());
+    bluetooth_sockets_.pop();
+    LeaveCriticalSection(&critical_section_);
+
+    return std::move(bluetoothSocket);
+  } else {
+    bluetooth_sockets_ = {};
+    LeaveCriticalSection(&critical_section_);
+  }
+
  return nullptr;
 }

+Exception BluetoothServerSocket::StartListening(
+    const std::string& service_name, const std::string& service_uuid) {
+  EnterCriticalSection(&critical_section_);
+
+  winrt::guid service(service_uuid);
+
+  // Create the StreamSocketListener
+  stream_socket_listener_ = StreamSocketListener();
+
+  // Configure control property
+  stream_socket_listener_.Control().QualityOfService(
+      SocketQualityOfService::LowLatency);
+
+  stream_socket_listener_.Control().KeepAlive(true);
+
+  // Note From the perspective of a StreamSocket, a Parallel Patterns Library
+  // (PPL) completion handler is done executing (and the socket is eligible for
+  // disposal) before the continuation body runs. So, to keep your socket from
+  // being disposed if you want to use it inside a continuation, you'll need to
+  // use one of the techniques described in References to StreamSockets in C++
+  // PPL continuations.
+  // Assign ConnectionReceived event to event handler on the server socket
+  stream_socket_listener_.ConnectionReceived(
+      [this](StreamSocketListener streamSocketListener,
+             StreamSocketListenerConnectionReceivedEventArgs args) {
+        EnterCriticalSection(&critical_section_);
+        if (!closed_) {
+          this->bluetooth_sockets_.push(
+              std::make_unique<BluetoothSocket>(args.Socket()));
+        }
+        LeaveCriticalSection(&critical_section_);
+      });
+
+  try {
+    auto rfcommProviderRef =
+        RfcommServiceProvider::CreateAsync(RfcommServiceId::FromUuid(service))
+            .get();
+
+    rfcomm_provider_ = &rfcommProviderRef;
+
+    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;
+    stream_socket_listener_
+        .BindServiceNameAsync(winrt::to_hstring(service_name.c_str()))
+        .get();
+
+    // Set the SDP attributes and start Bluetooth advertising
+    InitializeServiceSdpAttributes(*rfcomm_provider_, service_name);
+  } catch (std::exception exception) {
+    // We will log and eat the exception since the caller
+    // expects nullptr if it fails
+    NEARBY_LOGS(ERROR) << __func__ << ": Exception setting up for listen: "
+                       << exception.what();
+
+    LeaveCriticalSection(&critical_section_);
+
+    return {Exception::kFailed};
+  }
+
+  try {
+    rfcomm_provider_->StartAdvertising(
+        stream_socket_listener_.as<StreamSocketListener>(), true);
+  } catch (std::exception exception) {
+    // We will log and eat the exception since the caller
+    // expects nullptr if it fails
+    NEARBY_LOGS(ERROR) << __func__ << ": Exception calling StartAdvertising: "
+                       << exception.what();
+
+    LeaveCriticalSection(&critical_section_);
+
+    return {Exception::kFailed};
+  }
+
+  LeaveCriticalSection(&critical_section_);
+
+  return {Exception::kSuccess};
+}
+
+void BluetoothServerSocket::InitializeServiceSdpAttributes(
+    RfcommServiceProvider rfcommProvider, std::string service_name) {
+  auto sdpWriter = DataWriter();
+
+  // Write the Service Name Attribute.
+  sdpWriter.WriteByte(Constants::SdpServiceNameAttributeType);
+
+  // The length of the UTF-8 encoded Service Name SDP Attribute.
+  sdpWriter.WriteByte(service_name.size());
+
+  // The UTF-8 encoded Service Name value.
+  sdpWriter.UnicodeEncoding(UnicodeEncoding::Utf8);
+  sdpWriter.WriteString(winrt::to_hstring(service_name));
+
+  // Set the SDP Attribute on the RFCOMM Service Provider.
+  rfcommProvider.SdpRawAttributes().Insert(Constants::SdpServiceNameAttributeId,
+                                           sdpWriter.DetachBuffer());
+}
+
 // https://developer.android.com/reference/android/bluetooth/BluetoothServerSocket.html#close()
 //
 // Returns Exception::kIo on error, Exception::kSuccess otherwise.
-// TODO(b/184975123): replace with real implementation.
-Exception BluetoothServerSocket::Close() { return Exception(); }
+Exception BluetoothServerSocket::Close() {
+  EnterCriticalSection(&critical_section_);
+  closed_ = true;
+  bluetooth_sockets_ = {};
+  rfcomm_provider_->StopAdvertising();
+  LeaveCriticalSection(&critical_section_);

+  return {Exception::kSuccess};
+}
 }  // namespace windows
 }  // namespace nearby
 }  // namespace location
@@ -15,14 +15,60 @@
 #ifndef PLATFORM_IMPL_WINDOWS_BLUETOOTH_CLASSIC_SERVER_SOCKET_H_
 #define PLATFORM_IMPL_WINDOWS_BLUETOOTH_CLASSIC_SERVER_SOCKET_H_

+#include <Windows.h>
+
+#include <queue>
+
 #include "platform/api/bluetooth_classic.h"
+#include "platform/impl/windows/bluetooth_classic_socket.h"
+#include "platform/impl/windows/generated/winrt/Windows.Devices.Bluetooth.Rfcomm.h"
+#include "platform/impl/windows/generated/winrt/Windows.Foundation.h"
+#include "platform/impl/windows/generated/winrt/Windows.Networking.Sockets.h"
+#include "platform/impl/windows/generated/winrt/base.h"

 namespace location {
 namespace nearby {
 namespace windows {
+
+// Supports listening for an incoming network connection using Bluetooth RFCOMM.
+// https://docs.microsoft.com/en-us/uwp/api/windows.networking.sockets.streamsocketlistener?view=winrt-20348
+using winrt::Windows::Networking::Sockets::StreamSocketListener;
+
+// Provides data for a ConnectionReceived event on a StreamSocketListener
+// object.
+// https://docs.microsoft.com/en-us/uwp/api/windows.networking.sockets.streamsocketlistenerconnectionreceivedeventargs?view=winrt-20348
+using winrt::Windows::Networking::Sockets::
+    StreamSocketListenerConnectionReceivedEventArgs;
+
+// Represents an asynchronous action.
+// https://docs.microsoft.com/en-us/uwp/api/windows.foundation.iasyncaction?view=winrt-20348
+using winrt::Windows::Foundation::IAsyncAction;
+
+// Specifies the quality of service for a StreamSocket object.
+// https://docs.microsoft.com/en-us/uwp/api/windows.networking.sockets.socketqualityofservice?view=winrt-20348
+using winrt::Windows::Networking::Sockets::SocketQualityOfService;
+
+// Represents an instance of a local RFCOMM service.
+// https://docs.microsoft.com/en-us/uwp/api/windows.devices.bluetooth.rfcomm.rfcommserviceprovider?view=winrt-20348
+using winrt::Windows::Devices::Bluetooth::Rfcomm::RfcommServiceProvider;
+
+// Represents an RFCOMM service ID.
+//  https://docs.microsoft.com/en-us/uwp/api/windows.devices.bluetooth.rfcomm.rfcommserviceid?view=winrt-20348
+using winrt::Windows::Devices::Bluetooth::Rfcomm::RfcommServiceId;
+
+// Writes data to an output stream.
+// https://docs.microsoft.com/en-us/uwp/api/windows.storage.streams.datawriter?view=winrt-20348
+using winrt::Windows::Storage::Streams::DataWriter;
+
+// Specifies the type of character encoding for a stream.
+// https://docs.microsoft.com/en-us/uwp/api/windows.storage.streams.unicodeencoding?view=winrt-20348
+using winrt::Windows::Storage::Streams::UnicodeEncoding;
+
 // https://developer.android.com/reference/android/bluetooth/BluetoothServerSocket.html.
 class BluetoothServerSocket : public api::BluetoothServerSocket {
 public:
+  BluetoothServerSocket();
+
  // TODO(b/184975123): replace with real implementation.
  ~BluetoothServerSocket() override;

@@ -34,14 +80,31 @@ class BluetoothServerSocket : public api::BluetoothServerSocket {
  // On success, returns connected socket, ready to exchange data.
  // Returns nullptr on error.
  // Once error is reported, it is permanent, and ServerSocket has to be closed.
-  // TODO(b/184975123): replace with real implementation.
  std::unique_ptr<api::BluetoothSocket> Accept() override;

  // https://developer.android.com/reference/android/bluetooth/BluetoothServerSocket.html#close()
  //
  // Returns Exception::kIo on error, Exception::kSuccess otherwise.
-  // TODO(b/184975123): replace with real implementation.
  Exception Close() override;
+
+  Exception StartListening(const std::string& service_name,
+                           const std::string& service_uuid);
+
+ private:
+  void InitializeServiceSdpAttributes(RfcommServiceProvider rfcommProvider,
+                                      std::string service_name);
+
+  // This is used to store sockets in case Accept hasn't been called. Once
+  // Accept has been called the socket is popped from the queue and returned to
+  // the caller
+  std::queue<std::unique_ptr<BluetoothSocket>> bluetooth_sockets_;
+
+  StreamSocketListener stream_socket_listener_;
+
+  CRITICAL_SECTION critical_section_;
+  bool closed_ = false;
+
+  RfcommServiceProvider* rfcomm_provider_;
 };

 }  // namespace windows
@@ -16,6 +16,7 @@
 #define PLATFORM_IMPL_WINDOWS_BLUETOOTH_CLASSIC_SOCKET_H_

 #include "platform/api/bluetooth_classic.h"
+
 #include "platform/impl/windows/generated/winrt/Windows.Foundation.h"
 #include "platform/impl/windows/generated/winrt/Windows.Networking.Sockets.h"
 #include "platform/impl/windows/generated/winrt/Windows.Storage.Streams.h"
@@ -65,6 +66,10 @@ class BluetoothSocket : public api::BluetoothSocket {
 public:
  BluetoothSocket();

+  BluetoothSocket(
+      winrt::Windows::Networking::Sockets::StreamSocket streamSocket)
+      : windows_socket_(streamSocket) {}
+
  // TODO(b/184975123): replace with real implementation.
  ~BluetoothSocket() override;

@@ -15,6 +15,9 @@
 #ifndef PLATFORM_IMPL_WINDOWS_UTILS_H_
 #define PLATFORM_IMPL_WINDOWS_UTILS_H_

+#include <Windows.h>
+#include <stdio.h>
+
 #include <string>

 namespace location {
@@ -23,7 +26,19 @@ namespace windows {

 std::string uint64_to_mac_address_string(uint64_t bluetoothAddress);

-}
+namespace Constants {
+// The Id of the Service Name SDP attribute
+const uint16_t SdpServiceNameAttributeId = 0x100;
+
+// The SDP Type of the Service Name SDP attribute.
+// The first byte in the SDP Attribute encodes the SDP Attribute Type as
+// follows:
+//    -  the Attribute Type size in the least significant 3 bits,
+//    -  the SDP Attribute Type value in the most significant 5 bits.
+const char SdpServiceNameAttributeType = (4 << 3) | 5;
+}  // namespace Constants
+
+}  // namespace windows
 }  // namespace nearby
 }  // namespace location