pw_bluetooth_sapphire/host/hci/android_extended_low_energy_advertiser.cc - pigweed/pigweed - Git at Google

 // Copyright 2023 The Pigweed Authors
 //
 // 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
 //
 //     https://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.

 #include "pw_bluetooth_sapphire/internal/host/hci/android_extended_low_energy_advertiser.h"

 #include <pw_bluetooth/hci_android.emb.h>
 #include <pw_bluetooth/hci_common.emb.h>

 #include "pw_bluetooth_sapphire/internal/host/hci-spec/vendor_protocol.h"
 #include "pw_bluetooth_sapphire/internal/host/transport/transport.h"

 namespace bt::hci {

 constexpr int8_t kTransmitPower =
     -25;  // Android range -70 to +20, select the middle for now

 namespace hci_android = hci_spec::vendor::android;

 AndroidExtendedLowEnergyAdvertiser::AndroidExtendedLowEnergyAdvertiser(
     hci::Transport::WeakPtr hci_ptr, uint8_t max_advertisements)
     : LowEnergyAdvertiser(std::move(hci_ptr)),
       max_advertisements_(max_advertisements),
       advertising_handle_map_(max_advertisements_),
       weak_self_(this) {
   auto self = weak_self_.GetWeakPtr();
   state_changed_event_handler_id_ =
       hci()->command_channel()->AddVendorEventHandler(
           hci_android::kLEMultiAdvtStateChangeSubeventCode,
           [self](const EmbossEventPacket& event_packet) {
             if (self.is_alive()) {
               return self->OnAdvertisingStateChangedSubevent(event_packet);
             }

             return CommandChannel::EventCallbackResult::kRemove;
           });
 }

 AndroidExtendedLowEnergyAdvertiser::~AndroidExtendedLowEnergyAdvertiser() {
   // This object is probably being destroyed because the stack is shutting down,
   // in which case the HCI layer may have already been destroyed.
   if (!hci().is_alive() || !hci()->command_channel()) {
     return;
   }
   hci()->command_channel()->RemoveEventHandler(state_changed_event_handler_id_);
   // TODO(fxbug.dev/42063496): This will only cancel one advertisement, after
   // which the SequentialCommandRunner will have been destroyed and no further
   // commands will be sent.
   StopAdvertising();
 }

 EmbossCommandPacket AndroidExtendedLowEnergyAdvertiser::BuildEnablePacket(
     const DeviceAddress& address,
     pw::bluetooth::emboss::GenericEnableParam enable) {
   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.GetHandle(address);
   BT_ASSERT(handle);

   auto packet = hci::EmbossCommandPacket::New<
       pw::bluetooth::vendor::android_hci::LEMultiAdvtEnableCommandWriter>(
       hci_android::kLEMultiAdvt);
   auto packet_view = packet.view_t();
   packet_view.vendor_command().sub_opcode().Write(
       hci_android::kLEMultiAdvtEnableSubopcode);
   packet_view.enable().Write(enable);
   packet_view.advertising_handle().Write(handle.value());
   return packet;
 }

 CommandChannel::CommandPacketVariant
 AndroidExtendedLowEnergyAdvertiser::BuildSetAdvertisingParams(
     const DeviceAddress& address,
     pw::bluetooth::emboss::LEAdvertisingType type,
     pw::bluetooth::emboss::LEOwnAddressType own_address_type,
     AdvertisingIntervalRange interval) {
   std::unique_ptr<CommandPacket> packet = CommandPacket::New(
       hci_android::kLEMultiAdvt,
       sizeof(hci_android::LEMultiAdvtSetAdvtParamCommandParams));
   packet->mutable_view()->mutable_payload_data().SetToZeros();
   auto payload = packet->mutable_payload<
       hci_android::LEMultiAdvtSetAdvtParamCommandParams>();

   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.MapHandle(address);
   if (!handle) {
     bt_log(WARN,
            "hci-le",
            "could not (al)locate advertising handle for address: %s",
            bt_str(address));
     return std::unique_ptr<CommandPacket>();
   }

   payload->opcode = hci_android::kLEMultiAdvtSetAdvtParamSubopcode;
   payload->adv_interval_min = htole16(interval.min());
   payload->adv_interval_max = htole16(interval.max());
   payload->adv_type = type;
   payload->own_address_type = own_address_type;
   payload->adv_channel_map = hci_spec::kLEAdvertisingChannelAll;
   payload->adv_filter_policy = hci_spec::LEAdvFilterPolicy::kAllowAll;
   payload->adv_handle = handle.value();
   payload->adv_tx_power = hci_spec::kLEExtendedAdvertisingTxPowerNoPreference;

   // We don't support directed advertising yet, so leave peer_address and
   // peer_address_type as 0x00
   // (|packet| parameters are initialized to zero above).

   return packet;
 }

 CommandChannel::CommandPacketVariant
 AndroidExtendedLowEnergyAdvertiser::BuildSetAdvertisingData(
     const DeviceAddress& address, const AdvertisingData& data, AdvFlags flags) {
   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.GetHandle(address);
   BT_ASSERT(handle);

   std::unique_ptr<CommandPacket> packet = CommandPacket::New(
       hci_android::kLEMultiAdvt,
       sizeof(hci_android::LEMultiAdvtSetAdvtDataCommandParams));
   packet->mutable_view()->mutable_payload_data().SetToZeros();
   auto payload =
       packet
           ->mutable_payload<hci_android::LEMultiAdvtSetAdvtDataCommandParams>();

   payload->opcode = hci_android::kLEMultiAdvtSetAdvtDataSubopcode;
   payload->adv_data_length =
       static_cast<uint8_t>(data.CalculateBlockSize(/*include_flags=*/true));
   payload->adv_handle = handle.value();

   MutableBufferView data_view(payload->adv_data, payload->adv_data_length);
   data.WriteBlock(&data_view, flags);

   return packet;
 }

 CommandChannel::CommandPacketVariant
 AndroidExtendedLowEnergyAdvertiser::BuildUnsetAdvertisingData(
     const DeviceAddress& address) {
   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.GetHandle(address);
   BT_ASSERT(handle);

   std::unique_ptr<CommandPacket> packet = CommandPacket::New(
       hci_android::kLEMultiAdvt,
       sizeof(hci_android::LEMultiAdvtSetAdvtDataCommandParams));
   packet->mutable_view()->mutable_payload_data().SetToZeros();
   auto payload =
       packet
           ->mutable_payload<hci_android::LEMultiAdvtSetAdvtDataCommandParams>();

   payload->opcode = hci_android::kLEMultiAdvtSetAdvtDataSubopcode;
   payload->adv_data_length = 0;
   payload->adv_handle = handle.value();

   return packet;
 }

 CommandChannel::CommandPacketVariant
 AndroidExtendedLowEnergyAdvertiser::BuildSetScanResponse(
     const DeviceAddress& address, const AdvertisingData& scan_rsp) {
   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.GetHandle(address);
   BT_ASSERT(handle);

   std::unique_ptr<CommandPacket> packet = CommandPacket::New(
       hci_android::kLEMultiAdvt,
       sizeof(hci_android::LEMultiAdvtSetScanRespCommandParams));
   packet->mutable_view()->mutable_payload_data().SetToZeros();
   auto payload =
       packet
           ->mutable_payload<hci_android::LEMultiAdvtSetScanRespCommandParams>();

   payload->opcode = hci_android::kLEMultiAdvtSetScanRespSubopcode;
   payload->scan_rsp_data_length =
       static_cast<uint8_t>(scan_rsp.CalculateBlockSize());
   payload->adv_handle = handle.value();

   MutableBufferView scan_rsp_view(payload->scan_rsp_data,
                                   payload->scan_rsp_data_length);
   scan_rsp.WriteBlock(&scan_rsp_view, std::nullopt);
   return packet;
 }

 CommandChannel::CommandPacketVariant
 AndroidExtendedLowEnergyAdvertiser::BuildUnsetScanResponse(
     const DeviceAddress& address) {
   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.GetHandle(address);
   BT_ASSERT(handle);

   std::unique_ptr<CommandPacket> packet = CommandPacket::New(
       hci_android::kLEMultiAdvt,
       sizeof(hci_android::LEMultiAdvtSetScanRespCommandParams));
   packet->mutable_view()->mutable_payload_data().SetToZeros();
   auto payload =
       packet
           ->mutable_payload<hci_android::LEMultiAdvtSetScanRespCommandParams>();

   payload->opcode = hci_android::kLEMultiAdvtSetScanRespSubopcode;
   payload->scan_rsp_data_length = 0;
   payload->adv_handle = handle.value();

   return packet;
 }

 EmbossCommandPacket
 AndroidExtendedLowEnergyAdvertiser::BuildRemoveAdvertisingSet(
     const DeviceAddress& address) {
   std::optional<hci_spec::AdvertisingHandle> handle =
       advertising_handle_map_.GetHandle(address);
   BT_ASSERT(handle);

   auto packet = hci::EmbossCommandPacket::New<
       pw::bluetooth::vendor::android_hci::LEMultiAdvtEnableCommandWriter>(
       hci_android::kLEMultiAdvt);
   auto packet_view = packet.view_t();
   packet_view.vendor_command().sub_opcode().Write(
       hci_android::kLEMultiAdvtEnableSubopcode);
   packet_view.enable().Write(
       pw::bluetooth::emboss::GenericEnableParam::DISABLE);
   packet_view.advertising_handle().Write(handle.value());
   return packet;
 }

 void AndroidExtendedLowEnergyAdvertiser::StartAdvertising(
     const DeviceAddress& address,
     const AdvertisingData& data,
     const AdvertisingData& scan_rsp,
     AdvertisingOptions options,
     ConnectionCallback connect_callback,
     ResultFunction<> result_callback) {
   AdvertisingData copied_data;
   data.Copy(&copied_data);

   AdvertisingData copied_scan_rsp;
   scan_rsp.Copy(&copied_scan_rsp);

   // if there is an operation currently in progress, enqueue this operation and
   // we will get to it the next time we have a chance
   if (!hci_cmd_runner().IsReady()) {
     bt_log(INFO,
            "hci-le",
            "hci cmd runner not ready, queuing advertisement commands for now");

     op_queue_.push([this,
                     address,
                     data = std::move(copied_data),
                     scan_rsp = std::move(copied_scan_rsp),
                     options,
                     conn_cb = std::move(connect_callback),
                     result_cb = std::move(result_callback)]() mutable {
       StartAdvertising(address,
                        data,
                        scan_rsp,
                        options,
                        std::move(conn_cb),
                        std::move(result_cb));
     });

     return;
   }

   fit::result<HostError> result =
       CanStartAdvertising(address, data, scan_rsp, options);
   if (result.is_error()) {
     result_callback(ToResult(result.error_value()));
     return;
   }

   if (IsAdvertising(address)) {
     bt_log(DEBUG,
            "hci-le",
            "updating existing advertisement for %s",
            bt_str(address));
   }

   if (options.include_tx_power_level) {
     copied_data.SetTxPower(kTransmitPower);
     copied_scan_rsp.SetTxPower(kTransmitPower);
   }

   StartAdvertisingInternal(address,
                            copied_data,
                            copied_scan_rsp,
                            options.interval,
                            options.flags,
                            std::move(connect_callback),
                            std::move(result_callback));
 }

 void AndroidExtendedLowEnergyAdvertiser::StopAdvertising() {
   LowEnergyAdvertiser::StopAdvertising();
   advertising_handle_map_.Clear();

   // std::queue doesn't have a clear method so we have to resort to this
   // tomfoolery :(
   decltype(op_queue_) empty;
   std::swap(op_queue_, empty);
 }

 void AndroidExtendedLowEnergyAdvertiser::StopAdvertising(
     const DeviceAddress& address) {
   // if there is an operation currently in progress, enqueue this operation and
   // we will get to it the next time we have a chance
   if (!hci_cmd_runner().IsReady()) {
     bt_log(
         INFO,
         "hci-le",
         "hci cmd runner not ready, queueing stop advertising command for now");
     op_queue_.push([this, address]() { StopAdvertising(address); });
     return;
   }

   LowEnergyAdvertiser::StopAdvertisingInternal(address);
   advertising_handle_map_.RemoveAddress(address);
 }

 void AndroidExtendedLowEnergyAdvertiser::OnIncomingConnection(
     hci_spec::ConnectionHandle handle,
     pw::bluetooth::emboss::ConnectionRole role,
     const DeviceAddress& peer_address,
     const hci_spec::LEConnectionParameters& conn_params) {
   staged_connections_map_[handle] = {role, peer_address, conn_params};
 }

 // The LE multi-advertising state change subevent contains the mapping between
 // connection handle and advertising handle. After the LE multi-advertising
 // state change subevent, we have all the information necessary to create a
 // connection object within the Host layer.
 CommandChannel::EventCallbackResult
 AndroidExtendedLowEnergyAdvertiser::OnAdvertisingStateChangedSubevent(
     const EmbossEventPacket& event) {
   BT_ASSERT(event.event_code() == hci_spec::kVendorDebugEventCode);
   BT_ASSERT(event.view<pw::bluetooth::emboss::VendorDebugEventView>()
                 .subevent_code()
                 .Read() == hci_android::kLEMultiAdvtStateChangeSubeventCode);

   Result<> result = event.ToResult();
   if (bt_is_error(result,
                   ERROR,
                   "hci-le",
                   "advertising state change event, error received %s",
                   bt_str(result))) {
     return CommandChannel::EventCallbackResult::kContinue;
   }

   auto view = event.view<
       pw::bluetooth::vendor::android_hci::LEMultiAdvtStateChangeSubeventView>();

   hci_spec::ConnectionHandle connection_handle =
       view.connection_handle().Read();
   auto staged_parameters_node =
       staged_connections_map_.extract(connection_handle);

   if (staged_parameters_node.empty()) {
     bt_log(ERROR,
            "hci-le",
            "advertising state change event, staged params not available "
            "(handle: %d)",
            view.advertising_handle().Read());
     return CommandChannel::EventCallbackResult::kContinue;
   }

   hci_spec::AdvertisingHandle adv_handle = view.advertising_handle().Read();
   std::optional<DeviceAddress> opt_local_address =
       advertising_handle_map_.GetAddress(adv_handle);

   // We use the identity address as the local address if we aren't advertising
   // or otherwise don't know about this advertising set. This is obviously
   // wrong. However, the link will be disconnected in that case before it can
   // propagate to higher layers.
   static DeviceAddress identity_address =
       DeviceAddress(DeviceAddress::Type::kLEPublic, {0});
   DeviceAddress local_address = identity_address;
   if (opt_local_address) {
     local_address = opt_local_address.value();
   }

   StagedConnectionParameters staged = staged_parameters_node.mapped();

   CompleteIncomingConnection(connection_handle,
                              staged.role,
                              local_address,
                              staged.peer_address,
                              staged.conn_params);
   return CommandChannel::EventCallbackResult::kContinue;
 }

 void AndroidExtendedLowEnergyAdvertiser::OnCurrentOperationComplete() {
   if (op_queue_.empty()) {
     return;  // no more queued operations so nothing to do
   }

   fit::closure closure = std::move(op_queue_.front());
   op_queue_.pop();
   closure();
 }

 }  // namespace bt::hci
	// Copyright 2023 The Pigweed Authors
	//
	// 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
	//
	// https://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.

	#include "pw_bluetooth_sapphire/internal/host/hci/android_extended_low_energy_advertiser.h"

	#include <pw_bluetooth/hci_android.emb.h>
	#include <pw_bluetooth/hci_common.emb.h>

	#include "pw_bluetooth_sapphire/internal/host/hci-spec/vendor_protocol.h"
	#include "pw_bluetooth_sapphire/internal/host/transport/transport.h"

	namespace bt::hci {

	constexpr int8_t kTransmitPower =
	-25; // Android range -70 to +20, select the middle for now

	namespace hci_android = hci_spec::vendor::android;

	AndroidExtendedLowEnergyAdvertiser::AndroidExtendedLowEnergyAdvertiser(
	hci::Transport::WeakPtr hci_ptr, uint8_t max_advertisements)
	: LowEnergyAdvertiser(std::move(hci_ptr)),
	max_advertisements_(max_advertisements),
	advertising_handle_map_(max_advertisements_),
	weak_self_(this) {
	auto self = weak_self_.GetWeakPtr();
	state_changed_event_handler_id_ =
	hci()->command_channel()->AddVendorEventHandler(
	hci_android::kLEMultiAdvtStateChangeSubeventCode,
	[self](const EmbossEventPacket& event_packet) {
	if (self.is_alive()) {
	return self->OnAdvertisingStateChangedSubevent(event_packet);
	}

	return CommandChannel::EventCallbackResult::kRemove;
	});
	}

	AndroidExtendedLowEnergyAdvertiser::~AndroidExtendedLowEnergyAdvertiser() {
	// This object is probably being destroyed because the stack is shutting down,
	// in which case the HCI layer may have already been destroyed.
	if (!hci().is_alive() \|\| !hci()->command_channel()) {
	return;
	}
	hci()->command_channel()->RemoveEventHandler(state_changed_event_handler_id_);
	// TODO(fxbug.dev/42063496): This will only cancel one advertisement, after
	// which the SequentialCommandRunner will have been destroyed and no further
	// commands will be sent.
	StopAdvertising();
	}

	EmbossCommandPacket AndroidExtendedLowEnergyAdvertiser::BuildEnablePacket(
	const DeviceAddress& address,
	pw::bluetooth::emboss::GenericEnableParam enable) {
	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.GetHandle(address);
	BT_ASSERT(handle);

	auto packet = hci::EmbossCommandPacket::New<
	pw::bluetooth::vendor::android_hci::LEMultiAdvtEnableCommandWriter>(
	hci_android::kLEMultiAdvt);
	auto packet_view = packet.view_t();
	packet_view.vendor_command().sub_opcode().Write(
	hci_android::kLEMultiAdvtEnableSubopcode);
	packet_view.enable().Write(enable);
	packet_view.advertising_handle().Write(handle.value());
	return packet;
	}

	CommandChannel::CommandPacketVariant
	AndroidExtendedLowEnergyAdvertiser::BuildSetAdvertisingParams(
	const DeviceAddress& address,
	pw::bluetooth::emboss::LEAdvertisingType type,
	pw::bluetooth::emboss::LEOwnAddressType own_address_type,
	AdvertisingIntervalRange interval) {
	std::unique_ptr<CommandPacket> packet = CommandPacket::New(
	hci_android::kLEMultiAdvt,
	sizeof(hci_android::LEMultiAdvtSetAdvtParamCommandParams));
	packet->mutable_view()->mutable_payload_data().SetToZeros();
	auto payload = packet->mutable_payload<
	hci_android::LEMultiAdvtSetAdvtParamCommandParams>();

	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.MapHandle(address);
	if (!handle) {
	bt_log(WARN,
	"hci-le",
	"could not (al)locate advertising handle for address: %s",
	bt_str(address));
	return std::unique_ptr<CommandPacket>();
	}

	payload->opcode = hci_android::kLEMultiAdvtSetAdvtParamSubopcode;
	payload->adv_interval_min = htole16(interval.min());
	payload->adv_interval_max = htole16(interval.max());
	payload->adv_type = type;
	payload->own_address_type = own_address_type;
	payload->adv_channel_map = hci_spec::kLEAdvertisingChannelAll;
	payload->adv_filter_policy = hci_spec::LEAdvFilterPolicy::kAllowAll;
	payload->adv_handle = handle.value();
	payload->adv_tx_power = hci_spec::kLEExtendedAdvertisingTxPowerNoPreference;

	// We don't support directed advertising yet, so leave peer_address and
	// peer_address_type as 0x00
	// (\|packet\| parameters are initialized to zero above).

	return packet;
	}

	CommandChannel::CommandPacketVariant
	AndroidExtendedLowEnergyAdvertiser::BuildSetAdvertisingData(
	const DeviceAddress& address, const AdvertisingData& data, AdvFlags flags) {
	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.GetHandle(address);
	BT_ASSERT(handle);

	std::unique_ptr<CommandPacket> packet = CommandPacket::New(
	hci_android::kLEMultiAdvt,
	sizeof(hci_android::LEMultiAdvtSetAdvtDataCommandParams));
	packet->mutable_view()->mutable_payload_data().SetToZeros();
	auto payload =
	packet
	->mutable_payload<hci_android::LEMultiAdvtSetAdvtDataCommandParams>();

	payload->opcode = hci_android::kLEMultiAdvtSetAdvtDataSubopcode;
	payload->adv_data_length =
	static_cast<uint8_t>(data.CalculateBlockSize(/include_flags=/true));
	payload->adv_handle = handle.value();

	MutableBufferView data_view(payload->adv_data, payload->adv_data_length);
	data.WriteBlock(&data_view, flags);

	return packet;
	}

	CommandChannel::CommandPacketVariant
	AndroidExtendedLowEnergyAdvertiser::BuildUnsetAdvertisingData(
	const DeviceAddress& address) {
	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.GetHandle(address);
	BT_ASSERT(handle);

	std::unique_ptr<CommandPacket> packet = CommandPacket::New(
	hci_android::kLEMultiAdvt,
	sizeof(hci_android::LEMultiAdvtSetAdvtDataCommandParams));
	packet->mutable_view()->mutable_payload_data().SetToZeros();
	auto payload =
	packet
	->mutable_payload<hci_android::LEMultiAdvtSetAdvtDataCommandParams>();

	payload->opcode = hci_android::kLEMultiAdvtSetAdvtDataSubopcode;
	payload->adv_data_length = 0;
	payload->adv_handle = handle.value();

	return packet;
	}

	CommandChannel::CommandPacketVariant
	AndroidExtendedLowEnergyAdvertiser::BuildSetScanResponse(
	const DeviceAddress& address, const AdvertisingData& scan_rsp) {
	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.GetHandle(address);
	BT_ASSERT(handle);

	std::unique_ptr<CommandPacket> packet = CommandPacket::New(
	hci_android::kLEMultiAdvt,
	sizeof(hci_android::LEMultiAdvtSetScanRespCommandParams));
	packet->mutable_view()->mutable_payload_data().SetToZeros();
	auto payload =
	packet
	->mutable_payload<hci_android::LEMultiAdvtSetScanRespCommandParams>();

	payload->opcode = hci_android::kLEMultiAdvtSetScanRespSubopcode;
	payload->scan_rsp_data_length =
	static_cast<uint8_t>(scan_rsp.CalculateBlockSize());
	payload->adv_handle = handle.value();

	MutableBufferView scan_rsp_view(payload->scan_rsp_data,
	payload->scan_rsp_data_length);
	scan_rsp.WriteBlock(&scan_rsp_view, std::nullopt);
	return packet;
	}

	CommandChannel::CommandPacketVariant
	AndroidExtendedLowEnergyAdvertiser::BuildUnsetScanResponse(
	const DeviceAddress& address) {
	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.GetHandle(address);
	BT_ASSERT(handle);

	std::unique_ptr<CommandPacket> packet = CommandPacket::New(
	hci_android::kLEMultiAdvt,
	sizeof(hci_android::LEMultiAdvtSetScanRespCommandParams));
	packet->mutable_view()->mutable_payload_data().SetToZeros();
	auto payload =
	packet
	->mutable_payload<hci_android::LEMultiAdvtSetScanRespCommandParams>();

	payload->opcode = hci_android::kLEMultiAdvtSetScanRespSubopcode;
	payload->scan_rsp_data_length = 0;
	payload->adv_handle = handle.value();

	return packet;
	}

	EmbossCommandPacket
	AndroidExtendedLowEnergyAdvertiser::BuildRemoveAdvertisingSet(
	const DeviceAddress& address) {
	std::optional<hci_spec::AdvertisingHandle> handle =
	advertising_handle_map_.GetHandle(address);
	BT_ASSERT(handle);

	auto packet = hci::EmbossCommandPacket::New<
	pw::bluetooth::vendor::android_hci::LEMultiAdvtEnableCommandWriter>(
	hci_android::kLEMultiAdvt);
	auto packet_view = packet.view_t();
	packet_view.vendor_command().sub_opcode().Write(
	hci_android::kLEMultiAdvtEnableSubopcode);
	packet_view.enable().Write(
	pw::bluetooth::emboss::GenericEnableParam::DISABLE);
	packet_view.advertising_handle().Write(handle.value());
	return packet;
	}

	void AndroidExtendedLowEnergyAdvertiser::StartAdvertising(
	const DeviceAddress& address,
	const AdvertisingData& data,
	const AdvertisingData& scan_rsp,
	AdvertisingOptions options,
	ConnectionCallback connect_callback,
	ResultFunction<> result_callback) {
	AdvertisingData copied_data;
	data.Copy(&copied_data);

	AdvertisingData copied_scan_rsp;
	scan_rsp.Copy(&copied_scan_rsp);

	// if there is an operation currently in progress, enqueue this operation and
	// we will get to it the next time we have a chance
	if (!hci_cmd_runner().IsReady()) {
	bt_log(INFO,
	"hci-le",
	"hci cmd runner not ready, queuing advertisement commands for now");

	op_queue_.push([this,
	address,
	data = std::move(copied_data),
	scan_rsp = std::move(copied_scan_rsp),
	options,
	conn_cb = std::move(connect_callback),
	result_cb = std::move(result_callback)]() mutable {
	StartAdvertising(address,
	data,
	scan_rsp,
	options,
	std::move(conn_cb),
	std::move(result_cb));
	});

	return;
	}

	fit::result<HostError> result =
	CanStartAdvertising(address, data, scan_rsp, options);
	if (result.is_error()) {
	result_callback(ToResult(result.error_value()));
	return;
	}

	if (IsAdvertising(address)) {
	bt_log(DEBUG,
	"hci-le",
	"updating existing advertisement for %s",
	bt_str(address));
	}

	if (options.include_tx_power_level) {
	copied_data.SetTxPower(kTransmitPower);
	copied_scan_rsp.SetTxPower(kTransmitPower);
	}

	StartAdvertisingInternal(address,
	copied_data,
	copied_scan_rsp,
	options.interval,
	options.flags,
	std::move(connect_callback),
	std::move(result_callback));
	}

	void AndroidExtendedLowEnergyAdvertiser::StopAdvertising() {
	LowEnergyAdvertiser::StopAdvertising();
	advertising_handle_map_.Clear();

	// std::queue doesn't have a clear method so we have to resort to this
	// tomfoolery :(
	decltype(op_queue_) empty;
	std::swap(op_queue_, empty);
	}

	void AndroidExtendedLowEnergyAdvertiser::StopAdvertising(
	const DeviceAddress& address) {
	// if there is an operation currently in progress, enqueue this operation and
	// we will get to it the next time we have a chance
	if (!hci_cmd_runner().IsReady()) {
	bt_log(
	INFO,
	"hci-le",
	"hci cmd runner not ready, queueing stop advertising command for now");
	op_queue_.push([this, address]() { StopAdvertising(address); });
	return;
	}

	LowEnergyAdvertiser::StopAdvertisingInternal(address);
	advertising_handle_map_.RemoveAddress(address);
	}

	void AndroidExtendedLowEnergyAdvertiser::OnIncomingConnection(
	hci_spec::ConnectionHandle handle,
	pw::bluetooth::emboss::ConnectionRole role,
	const DeviceAddress& peer_address,
	const hci_spec::LEConnectionParameters& conn_params) {
	staged_connections_map_[handle] = {role, peer_address, conn_params};
	}

	// The LE multi-advertising state change subevent contains the mapping between
	// connection handle and advertising handle. After the LE multi-advertising
	// state change subevent, we have all the information necessary to create a
	// connection object within the Host layer.
	CommandChannel::EventCallbackResult
	AndroidExtendedLowEnergyAdvertiser::OnAdvertisingStateChangedSubevent(
	const EmbossEventPacket& event) {
	BT_ASSERT(event.event_code() == hci_spec::kVendorDebugEventCode);
	BT_ASSERT(event.view<pw::bluetooth::emboss::VendorDebugEventView>()
	.subevent_code()
	.Read() == hci_android::kLEMultiAdvtStateChangeSubeventCode);

	Result<> result = event.ToResult();
	if (bt_is_error(result,
	ERROR,
	"hci-le",
	"advertising state change event, error received %s",
	bt_str(result))) {
	return CommandChannel::EventCallbackResult::kContinue;
	}

	auto view = event.view<
	pw::bluetooth::vendor::android_hci::LEMultiAdvtStateChangeSubeventView>();

	hci_spec::ConnectionHandle connection_handle =
	view.connection_handle().Read();
	auto staged_parameters_node =
	staged_connections_map_.extract(connection_handle);

	if (staged_parameters_node.empty()) {
	bt_log(ERROR,
	"hci-le",
	"advertising state change event, staged params not available "
	"(handle: %d)",
	view.advertising_handle().Read());
	return CommandChannel::EventCallbackResult::kContinue;
	}

	hci_spec::AdvertisingHandle adv_handle = view.advertising_handle().Read();
	std::optional<DeviceAddress> opt_local_address =
	advertising_handle_map_.GetAddress(adv_handle);

	// We use the identity address as the local address if we aren't advertising
	// or otherwise don't know about this advertising set. This is obviously
	// wrong. However, the link will be disconnected in that case before it can
	// propagate to higher layers.
	static DeviceAddress identity_address =
	DeviceAddress(DeviceAddress::Type::kLEPublic, {0});
	DeviceAddress local_address = identity_address;
	if (opt_local_address) {
	local_address = opt_local_address.value();
	}

	StagedConnectionParameters staged = staged_parameters_node.mapped();

	CompleteIncomingConnection(connection_handle,
	staged.role,
	local_address,
	staged.peer_address,
	staged.conn_params);
	return CommandChannel::EventCallbackResult::kContinue;
	}

	void AndroidExtendedLowEnergyAdvertiser::OnCurrentOperationComplete() {
	if (op_queue_.empty()) {
	return; // no more queued operations so nothing to do
	}

	fit::closure closure = std::move(op_queue_.front());
	op_queue_.pop();
	closure();
	}

	} // namespace bt::hci