/* * Copyright 2022 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #define LOG_TAG "BTAudioClientAIDL" #include "client_interface_aidl.h" #include #include #include #include #include #include "bta/ag/bta_ag_int.h" namespace bluetooth { namespace audio { namespace aidl { std::ostream& operator<<(std::ostream& os, const BluetoothAudioCtrlAck& ack) { switch (ack) { case BluetoothAudioCtrlAck::SUCCESS_FINISHED: return os << "SUCCESS_FINISHED"; case BluetoothAudioCtrlAck::PENDING: return os << "PENDING"; case BluetoothAudioCtrlAck::FAILURE_UNSUPPORTED: return os << "FAILURE_UNSUPPORTED"; case BluetoothAudioCtrlAck::FAILURE_BUSY: return os << "FAILURE_BUSY"; case BluetoothAudioCtrlAck::FAILURE_DISCONNECTING: return os << "FAILURE_DISCONNECTING"; case BluetoothAudioCtrlAck::FAILURE: return os << "FAILURE"; default: return os << "UNDEFINED " << static_cast(ack); } } BluetoothAudioClientInterface::BluetoothAudioClientInterface( IBluetoothTransportInstance* instance) : provider_(nullptr), provider_factory_(nullptr), session_started_(false), data_mq_(nullptr), transport_(instance), latency_modes_({LatencyMode::FREE}) { death_recipient_ = ::ndk::ScopedAIBinder_DeathRecipient( AIBinder_DeathRecipient_new(binderDiedCallbackAidl)); } bool BluetoothAudioClientInterface::IsValid() const { return provider_ != nullptr; } bool BluetoothAudioClientInterface::is_aidl_available() { return AServiceManager_isDeclared( kDefaultAudioProviderFactoryInterface.c_str()); } std::vector BluetoothAudioClientInterface::GetAudioCapabilities() const { return capabilities_; } std::vector BluetoothAudioClientInterface::GetAudioCapabilities(SessionType session_type) { std::vector capabilities(0); if (!is_aidl_available()) { return capabilities; } auto provider_factory = IBluetoothAudioProviderFactory::fromBinder( ::ndk::SpAIBinder(AServiceManager_waitForService( kDefaultAudioProviderFactoryInterface.c_str()))); if (provider_factory == nullptr) { log::error("can't get capability from unknown factory"); return capabilities; } auto aidl_retval = provider_factory->getProviderCapabilities(session_type, &capabilities); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::getProviderCapabilities failure: {}", aidl_retval.getDescription()); } return capabilities; } std::optional BluetoothAudioClientInterface::GetProviderInfo( SessionType session_type, std::shared_ptr provider_factory) { if (!is_aidl_available() || !com::android::bluetooth::flags::a2dp_offload_codec_extensibility()) { return std::nullopt; } if (provider_factory == nullptr) { provider_factory = IBluetoothAudioProviderFactory::fromBinder( ::ndk::SpAIBinder(AServiceManager_waitForService( kDefaultAudioProviderFactoryInterface.c_str()))); } if (provider_factory == nullptr) { log::error("can't get provider info from unknown factory"); return std::nullopt; } std::optional provider_info = {}; auto aidl_retval = provider_factory->getProviderInfo(session_type, &provider_info); if (!aidl_retval.isOk()) { log::error("BluetoothAudioHal::getProviderInfo failure: {}", aidl_retval.getDescription()); return std::nullopt; } return provider_info; } std::optional BluetoothAudioClientInterface::GetA2dpConfiguration( std::vector const& remote_capabilities, A2dpConfigurationHint const& hint) const { if (!is_aidl_available() || !com::android::bluetooth::flags::a2dp_offload_codec_extensibility()) { return std::nullopt; } if (provider_ == nullptr) { log::error("can't get a2dp configuration from unknown provider"); return std::nullopt; } std::optional configuration = std::nullopt; auto aidl_retval = provider_->getA2dpConfiguration(remote_capabilities, hint, &configuration); if (!aidl_retval.isOk()) { log::error("getA2dpConfiguration failure: {}", aidl_retval.getDescription()); return std::nullopt; } return configuration; } std::optional BluetoothAudioClientInterface::ParseA2dpConfiguration( const CodecId& codec_id, const std::vector& configuration, CodecParameters* codec_parameters) const { A2dpStatus a2dp_status; if (provider_ == nullptr) { log::error("can not parse A2DP configuration because of unknown provider"); return std::nullopt; } auto aidl_retval = provider_->parseA2dpConfiguration( codec_id, configuration, codec_parameters, &a2dp_status); if (!aidl_retval.isOk()) { log::error("parseA2dpConfiguration failure: {}", aidl_retval.getDescription()); return std::nullopt; } return std::make_optional(a2dp_status); } void BluetoothAudioClientInterface::FetchAudioProvider() { if (!is_aidl_available()) { log::error("aidl is not supported on this platform."); return; } if (provider_ != nullptr) { log::warn("refetch"); } auto provider_factory = IBluetoothAudioProviderFactory::fromBinder( ::ndk::SpAIBinder(AServiceManager_waitForService( kDefaultAudioProviderFactoryInterface.c_str()))); if (provider_factory == nullptr) { log::error("can't get capability from unknown factory"); return; } capabilities_.clear(); auto aidl_retval = provider_factory->getProviderCapabilities( transport_->GetSessionType(), &capabilities_); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::getProviderCapabilities failure: {}", aidl_retval.getDescription()); return; } if (capabilities_.empty()) { log::warn("SessionType={} Not supported by BluetoothAudioHal", toString(transport_->GetSessionType())); return; } log::info("BluetoothAudioHal SessionType={} has {} AudioCapabilities", toString(transport_->GetSessionType()), capabilities_.size()); aidl_retval = provider_factory->openProvider(transport_->GetSessionType(), &provider_); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::openProvider failure: {}", aidl_retval.getDescription()); } log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); binder_status_t binder_status = AIBinder_linkToDeath( provider_factory->asBinder().get(), death_recipient_.get(), this); if (binder_status != STATUS_OK) { log::error("Failed to linkToDeath {}", static_cast(binder_status)); } provider_factory_ = std::move(provider_factory); log::info("IBluetoothAudioProvidersFactory::openProvider() returned {}{}", fmt::ptr(provider_.get()), (provider_->isRemote() ? " (remote)" : " (local)")); } BluetoothAudioSinkClientInterface::BluetoothAudioSinkClientInterface( IBluetoothSinkTransportInstance* sink) : BluetoothAudioClientInterface{sink}, sink_(sink) { FetchAudioProvider(); } BluetoothAudioSinkClientInterface::~BluetoothAudioSinkClientInterface() { if (provider_factory_ != nullptr) { AIBinder_unlinkToDeath(provider_factory_->asBinder().get(), death_recipient_.get(), nullptr); } } BluetoothAudioSourceClientInterface::BluetoothAudioSourceClientInterface( IBluetoothSourceTransportInstance* source) : BluetoothAudioClientInterface{source}, source_(source) { FetchAudioProvider(); } BluetoothAudioSourceClientInterface::~BluetoothAudioSourceClientInterface() { if (provider_factory_ != nullptr) { AIBinder_unlinkToDeath(provider_factory_->asBinder().get(), death_recipient_.get(), nullptr); } } void BluetoothAudioClientInterface::binderDiedCallbackAidl(void* ptr) { log::warn("restarting connection with new Audio Hal"); auto client = static_cast(ptr); if (client == nullptr) { log::error("null audio HAL died!"); return; } client->RenewAudioProviderAndSession(); } bool BluetoothAudioClientInterface::UpdateAudioConfig( const AudioConfiguration& audio_config) { bool is_software_session = (transport_->GetSessionType() == SessionType::A2DP_SOFTWARE_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::HEARING_AID_SOFTWARE_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_SOFTWARE_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_SOFTWARE_DECODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_BROADCAST_SOFTWARE_ENCODING_DATAPATH || (bta_ag_is_sco_managed_by_audio() && (transport_->GetSessionType() == SessionType::HFP_SOFTWARE_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::HFP_SOFTWARE_DECODING_DATAPATH))); bool is_a2dp_offload_session = (transport_->GetSessionType() == SessionType::A2DP_HARDWARE_OFFLOAD_ENCODING_DATAPATH); bool is_leaudio_unicast_offload_session = (transport_->GetSessionType() == SessionType::LE_AUDIO_HARDWARE_OFFLOAD_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_HARDWARE_OFFLOAD_DECODING_DATAPATH); bool is_leaudio_broadcast_offload_session = (transport_->GetSessionType() == SessionType::LE_AUDIO_BROADCAST_HARDWARE_OFFLOAD_ENCODING_DATAPATH); auto audio_config_tag = audio_config.getTag(); bool is_software_audio_config = (is_software_session && audio_config_tag == AudioConfiguration::pcmConfig); bool is_a2dp_offload_audio_config = (is_a2dp_offload_session && (audio_config_tag == AudioConfiguration::a2dpConfig || audio_config_tag == AudioConfiguration::a2dp)); bool is_leaudio_unicast_offload_audio_config = (is_leaudio_unicast_offload_session && audio_config_tag == AudioConfiguration::leAudioConfig); bool is_leaudio_broadcast_offload_audio_config = (is_leaudio_broadcast_offload_session && audio_config_tag == AudioConfiguration::leAudioBroadcastConfig); bool is_hfp_offload_audio_config = (bta_ag_is_sco_managed_by_audio() && transport_->GetSessionType() == SessionType::HFP_HARDWARE_OFFLOAD_DATAPATH && audio_config_tag == AudioConfiguration::hfpConfig); if (!is_software_audio_config && !is_a2dp_offload_audio_config && !is_leaudio_unicast_offload_audio_config && !is_leaudio_broadcast_offload_audio_config && !is_hfp_offload_audio_config) { return false; } transport_->UpdateAudioConfiguration(audio_config); if (provider_ == nullptr) { log::info("BluetoothAudioHal nullptr, update it as session started"); return true; } if (!session_started_) { log::info("BluetoothAudioHal session has not started"); return true; } auto aidl_retval = provider_->updateAudioConfiguration(audio_config); if (!aidl_retval.isOk()) { if (audio_config.getTag() != transport_->GetAudioConfiguration().getTag()) { log::warn( "BluetoothAudioHal audio config type: {} doesn't " "match provider's audio config type: {}", ::aidl::android::hardware::bluetooth::audio::toString( audio_config.getTag()), ::aidl::android::hardware::bluetooth::audio::toString( transport_->GetAudioConfiguration().getTag())); } else { log::warn("BluetoothAudioHal is not ready: {} ", aidl_retval.getDescription()); } } return true; } bool BluetoothAudioClientInterface::SetAllowedLatencyModes( std::vector latency_modes) { if (provider_ == nullptr) { log::info("BluetoothAudioHal nullptr"); return false; } if (latency_modes.empty()) { latency_modes_.clear(); latency_modes_.push_back(LatencyMode::FREE); } else { /* Ensure that FREE is always included and remove duplicates if any */ std::set temp_set(latency_modes.begin(), latency_modes.end()); temp_set.insert(LatencyMode::FREE); latency_modes_.clear(); latency_modes_.assign(temp_set.begin(), temp_set.end()); } for (auto latency_mode : latency_modes) { log::info( "Latency mode allowed: {}", ::aidl::android::hardware::bluetooth::audio::toString(latency_mode)); } /* Low latency mode is used if modes other than FREE are present */ bool allowed = (latency_modes_.size() > 1); log::info("Latency mode allowed: {}", allowed); auto aidl_retval = provider_->setLowLatencyModeAllowed(allowed); if (!aidl_retval.isOk()) { log::warn( "BluetoothAudioHal is not ready: {}. latency_modes_ is saved and it " "will be sent to BluetoothAudioHal at StartSession.", aidl_retval.getDescription()); } return true; } int BluetoothAudioClientInterface::StartSession() { std::lock_guard guard(internal_mutex_); if (provider_ == nullptr) { log::error("BluetoothAudioHal nullptr"); session_started_ = false; return -EINVAL; } if (session_started_) { log::error("session started already"); return -EBUSY; } std::shared_ptr stack_if = ndk::SharedRefBase::make(transport_, provider_); std::unique_ptr data_mq; DataMQDesc mq_desc; auto aidl_retval = provider_->startSession( stack_if, transport_->GetAudioConfiguration(), latency_modes_, &mq_desc); if (!aidl_retval.isOk()) { if (aidl_retval.getExceptionCode() == EX_ILLEGAL_ARGUMENT) { log::error("BluetoothAudioHal Error: {}, audioConfig={}", aidl_retval.getDescription(), transport_->GetAudioConfiguration().toString()); } else { log::fatal("BluetoothAudioHal failure: {}", aidl_retval.getDescription()); } return -EPROTO; } data_mq.reset(new DataMQ(mq_desc)); if (data_mq && data_mq->isValid()) { data_mq_ = std::move(data_mq); } else if (transport_->GetSessionType() == SessionType::A2DP_HARDWARE_OFFLOAD_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_HARDWARE_OFFLOAD_DECODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_HARDWARE_OFFLOAD_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType:: LE_AUDIO_BROADCAST_HARDWARE_OFFLOAD_ENCODING_DATAPATH || (bta_ag_is_sco_managed_by_audio() && transport_->GetSessionType() == SessionType::HFP_HARDWARE_OFFLOAD_DATAPATH)) { transport_->ResetPresentationPosition(); session_started_ = true; return 0; } if (data_mq_ && data_mq_->isValid()) { transport_->ResetPresentationPosition(); session_started_ = true; return 0; } else { if (!data_mq_) { log::error("Failed to obtain audio data path"); } if (data_mq_ && !data_mq_->isValid()) { log::error("Audio data path is invalid"); } session_started_ = false; return -EIO; } } void BluetoothAudioClientInterface::StreamStarted( const BluetoothAudioCtrlAck& ack) { if (provider_ == nullptr) { log::error("BluetoothAudioHal nullptr"); return; } if (ack == BluetoothAudioCtrlAck::PENDING) { log::info("{} ignored", ack); return; } BluetoothAudioStatus status = BluetoothAudioCtrlAckToHalStatus(ack); auto aidl_retval = provider_->streamStarted(status); if (!aidl_retval.isOk()) { log::error("BluetoothAudioHal failure: {}", aidl_retval.getDescription()); } } void BluetoothAudioClientInterface::StreamSuspended( const BluetoothAudioCtrlAck& ack) { if (provider_ == nullptr) { log::error("BluetoothAudioHal nullptr"); return; } if (ack == BluetoothAudioCtrlAck::PENDING) { log::info("{} ignored", ack); return; } BluetoothAudioStatus status = BluetoothAudioCtrlAckToHalStatus(ack); auto aidl_retval = provider_->streamSuspended(status); if (!aidl_retval.isOk()) { log::error("BluetoothAudioHal failure: {}", aidl_retval.getDescription()); } } int BluetoothAudioClientInterface::EndSession() { std::lock_guard guard(internal_mutex_); if (!session_started_) { log::info("session ended already"); return 0; } session_started_ = false; if (provider_ == nullptr) { log::error("BluetoothAudioHal nullptr"); return -EINVAL; } data_mq_ = nullptr; auto aidl_retval = provider_->endSession(); if (!aidl_retval.isOk()) { log::error("BluetoothAudioHal failure: {}", aidl_retval.getDescription()); return -EPROTO; } return 0; } void BluetoothAudioClientInterface::FlushAudioData() { if (transport_->GetSessionType() == SessionType::LE_AUDIO_HARDWARE_OFFLOAD_ENCODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_HARDWARE_OFFLOAD_DECODING_DATAPATH || transport_->GetSessionType() == SessionType::LE_AUDIO_BROADCAST_HARDWARE_OFFLOAD_ENCODING_DATAPATH || (bta_ag_is_sco_managed_by_audio() && transport_->GetSessionType() == SessionType::HFP_HARDWARE_OFFLOAD_DATAPATH)) { return; } if (data_mq_ == nullptr || !data_mq_->isValid()) { log::warn("data_mq_ invalid"); return; } size_t size = data_mq_->availableToRead(); std::vector buffer(size); if (data_mq_->read(buffer.data(), size) != size) { log::warn("failed to flush data queue!"); } } size_t BluetoothAudioSinkClientInterface::ReadAudioData(uint8_t* p_buf, uint32_t len) { if (!IsValid()) { log::error("BluetoothAudioHal is not valid"); return 0; } if (p_buf == nullptr || len == 0) return 0; std::lock_guard guard(internal_mutex_); size_t total_read = 0; int timeout_ms = kDefaultDataReadTimeoutMs; do { if (data_mq_ == nullptr || !data_mq_->isValid()) break; size_t avail_to_read = data_mq_->availableToRead(); if (avail_to_read) { if (avail_to_read > len - total_read) { avail_to_read = len - total_read; } if (data_mq_->read((MqDataType*)p_buf + total_read, avail_to_read) == 0) { log::warn("len={} total_read={} failed", len, total_read); break; } total_read += avail_to_read; } else if (timeout_ms >= kDefaultDataReadPollIntervalMs) { std::this_thread::sleep_for( std::chrono::milliseconds(kDefaultDataReadPollIntervalMs)); timeout_ms -= kDefaultDataReadPollIntervalMs; continue; } else { log::warn("{}/{} no data {} ms", len - total_read, len, kDefaultDataReadTimeoutMs - timeout_ms); break; } } while (total_read < len); if (timeout_ms < (kDefaultDataReadTimeoutMs - kDefaultDataReadPollIntervalMs) && timeout_ms >= kDefaultDataReadPollIntervalMs) { log::verbose("underflow {} -> {} read {} ms", len, total_read, kDefaultDataReadTimeoutMs - timeout_ms); } else { log::verbose("{} -> {} read", len, total_read); } sink_->LogBytesRead(total_read); return total_read; } void BluetoothAudioClientInterface::RenewAudioProviderAndSession() { // NOTE: must be invoked on the same thread where this // BluetoothAudioClientInterface is running FetchAudioProvider(); if (session_started_) { log::info("Restart the session while audio HAL recovering"); session_started_ = false; StartSession(); } } size_t BluetoothAudioSourceClientInterface::WriteAudioData(const uint8_t* p_buf, uint32_t len) { if (!IsValid()) { log::error("BluetoothAudioHal is not valid"); return 0; } if (p_buf == nullptr || len == 0) return 0; std::lock_guard guard(internal_mutex_); size_t total_written = 0; int timeout_ms = kDefaultDataWriteTimeoutMs; do { if (data_mq_ == nullptr || !data_mq_->isValid()) break; size_t avail_to_write = data_mq_->availableToWrite(); if (avail_to_write) { if (avail_to_write > len - total_written) { avail_to_write = len - total_written; } if (data_mq_->write((const MqDataType*)p_buf + total_written, avail_to_write) == 0) { log::warn("len={} total_written={} failed", len, total_written); break; } total_written += avail_to_write; } else if (timeout_ms >= kDefaultDataWritePollIntervalMs) { std::this_thread::sleep_for( std::chrono::milliseconds(kDefaultDataWritePollIntervalMs)); timeout_ms -= kDefaultDataWritePollIntervalMs; continue; } else { log::warn("{}/{} no data {} ms", len - total_written, len, kDefaultDataWriteTimeoutMs - timeout_ms); break; } } while (total_written < len); if (timeout_ms < (kDefaultDataWriteTimeoutMs - kDefaultDataWritePollIntervalMs) && timeout_ms >= kDefaultDataWritePollIntervalMs) { log::verbose("underflow {} -> {} read {} ms", len, total_written, kDefaultDataWriteTimeoutMs - timeout_ms); } else { log::verbose("{} -> {} written", len, total_written); } source_->LogBytesWritten(total_written); return total_written; } void BluetoothAudioClientInterface::SetCodecPriority(CodecId codec_id, int32_t priority) { log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); auto aidl_retval = provider_->setCodecPriority(codec_id, priority); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::setCodecPriority failure: {}", aidl_retval.getDescription()); } } std::vector BluetoothAudioClientInterface::GetLeAudioAseConfiguration( std::optional>>& remoteSinkAudioCapabilities, std::optional>>& remoteSourceAudioCapabilities, std::vector& requirements) { log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); std::vector configurations; auto aidl_retval = provider_->getLeAudioAseConfiguration( remoteSinkAudioCapabilities, remoteSourceAudioCapabilities, requirements, &configurations); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::getLeAudioAseConfiguration failure: {}", aidl_retval.getDescription()); } log::info( "BluetoothAudioHal::getLeAudioAseConfiguration returned {} " "configurations.", configurations.size()); return configurations; } IBluetoothAudioProvider::LeAudioAseQosConfigurationPair BluetoothAudioClientInterface::getLeAudioAseQosConfiguration( IBluetoothAudioProvider::LeAudioAseQosConfigurationRequirement& qosRequirement) { log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); IBluetoothAudioProvider::LeAudioAseQosConfigurationPair qos_configuration; auto aidl_retval = provider_->getLeAudioAseQosConfiguration( qosRequirement, &qos_configuration); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::getLeAudioAseQosConfiguration failure: {}", aidl_retval.getDescription()); } return qos_configuration; } void BluetoothAudioClientInterface::onSinkAseMetadataChanged( IBluetoothAudioProvider::AseState state, int32_t cigId, int32_t cisId, std::optional>>& metadata) { log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); auto aidl_retval = provider_->onSinkAseMetadataChanged(state, cigId, cisId, metadata); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::onSinkAseMetadataChanged failure: {}", aidl_retval.getDescription()); } } void BluetoothAudioClientInterface::onSourceAseMetadataChanged( IBluetoothAudioProvider::AseState state, int32_t cigId, int32_t cisId, std::optional>>& metadata) { log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); auto aidl_retval = provider_->onSourceAseMetadataChanged(state, cigId, cisId, metadata); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::onSinkAseMetadataChanged failure: {}", aidl_retval.getDescription()); } } IBluetoothAudioProvider::LeAudioBroadcastConfigurationSetting BluetoothAudioClientInterface::getLeAudioBroadcastConfiguration( const std::optional>>& remoteSinkAudioCapabilities, const IBluetoothAudioProvider::LeAudioBroadcastConfigurationRequirement& requirement) { log::assert_that(provider_ != nullptr, "assert failed: provider_ != nullptr"); IBluetoothAudioProvider::LeAudioBroadcastConfigurationSetting setting; auto aidl_retval = provider_->getLeAudioBroadcastConfiguration( remoteSinkAudioCapabilities, requirement, &setting); if (!aidl_retval.isOk()) { log::fatal("BluetoothAudioHal::onSinkAseMetadataChanged failure: {}", aidl_retval.getDescription()); } return setting; } } // namespace aidl } // namespace audio } // namespace bluetooth