/* * Copyright 2019 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. */ #include "l2cap/le/internal/signalling_manager.h" #include #include "common/bind.h" #include "l2cap/internal/data_pipeline_manager.h" #include "l2cap/internal/dynamic_channel_impl.h" #include "l2cap/internal/le_credit_based_channel_data_controller.h" #include "l2cap/l2cap_packets.h" #include "l2cap/le/internal/link.h" #include "os/log.h" #include "packet/raw_builder.h" namespace bluetooth { namespace l2cap { namespace le { namespace internal { static constexpr auto kTimeout = std::chrono::seconds(3); LeSignallingManager::LeSignallingManager(os::Handler* handler, Link* link, l2cap::internal::DataPipelineManager* data_pipeline_manager, DynamicChannelServiceManagerImpl* dynamic_service_manager, l2cap::internal::DynamicChannelAllocator* channel_allocator) : handler_(handler), link_(link), data_pipeline_manager_(data_pipeline_manager), dynamic_service_manager_(dynamic_service_manager), channel_allocator_(channel_allocator), alarm_(handler) { ASSERT(handler_ != nullptr); ASSERT(link_ != nullptr); signalling_channel_ = link_->AllocateFixedChannel(kLeSignallingCid, SecurityPolicy::NO_SECURITY_WHATSOEVER_PLAINTEXT_TRANSPORT_OK); signalling_channel_->GetQueueUpEnd()->RegisterDequeue( handler_, common::Bind(&LeSignallingManager::on_incoming_packet, common::Unretained(this))); enqueue_buffer_ = std::make_unique>(signalling_channel_->GetQueueUpEnd()); } LeSignallingManager::~LeSignallingManager() { enqueue_buffer_.reset(); signalling_channel_->GetQueueUpEnd()->UnregisterDequeue(); signalling_channel_ = nullptr; } void LeSignallingManager::SendConnectionRequest(Psm psm, Cid local_cid, Mtu mtu) { dynamic_service_manager_->GetSecurityEnforcementInterface()->Enforce( link_->GetDevice(), dynamic_service_manager_->GetService(psm)->GetSecurityPolicy(), handler_->BindOnceOn(this, &LeSignallingManager::on_security_result_for_outgoing, psm, local_cid, mtu)); } void LeSignallingManager::on_security_result_for_outgoing(Psm psm, Cid local_cid, Mtu mtu, bool result) { if (!result) { LOG_WARN("Security requirement can't be satisfied. Dropping connection request"); return; } PendingCommand pending_command = PendingCommand::CreditBasedConnectionRequest( next_signal_id_, psm, local_cid, mtu, link_->GetMps(), link_->GetInitialCredit()); next_signal_id_++; pending_commands_.push(pending_command); if (pending_commands_.size() == 1) { handle_send_next_command(); } } void LeSignallingManager::SendDisconnectRequest(Cid scid, Cid dcid) { PendingCommand pending_command = PendingCommand::DisconnectionRequest(next_signal_id_, scid, dcid); next_signal_id_++; pending_commands_.push(pending_command); if (pending_commands_.size() == 1) { handle_send_next_command(); } } void LeSignallingManager::SendConnectionParameterUpdateRequest( uint16_t interval_min, uint16_t interval_max, uint16_t peripheral_latency, uint16_t timeout_multiplier) { PendingCommand pending_command = PendingCommand::ConnectionParameterUpdate( next_signal_id_, interval_min, interval_max, peripheral_latency, timeout_multiplier); next_signal_id_++; pending_commands_.push(pending_command); if (pending_commands_.size() == 1) { handle_send_next_command(); } } void LeSignallingManager::SendConnectionParameterUpdateResponse(SignalId signal_id, ConnectionParameterUpdateResponseResult result) { auto builder = ConnectionParameterUpdateResponseBuilder::Create(signal_id.Value(), result); enqueue_buffer_->Enqueue(std::move(builder), handler_); } void LeSignallingManager::SendCredit(Cid local_cid, uint16_t credits) { auto builder = LeFlowControlCreditBuilder::Create(next_signal_id_.Value(), local_cid, credits); next_signal_id_++; enqueue_buffer_->Enqueue(std::move(builder), handler_); } void LeSignallingManager::SendEnhancedConnectionRequest(Psm psm, std::vector local_cid, Mtu mtu) {} void LeSignallingManager::SendEnhancedReconfigureRequest(std::vector local_cid, Mtu mtu) {} void LeSignallingManager::CancelAlarm() { alarm_.Cancel(); } void LeSignallingManager::OnCommandReject(LeCommandRejectView command_reject_view) { auto signal_id = command_reject_view.GetIdentifier(); if (signal_id != command_just_sent_.signal_id_) { LOG_WARN("Unexpected response: no pending request"); return; } alarm_.Cancel(); if (command_just_sent_.command_code_ == LeCommandCode::LE_CREDIT_BASED_CONNECTION_REQUEST) { link_->OnOutgoingConnectionRequestFail(command_just_sent_.source_cid_, LeCreditBasedConnectionResponseResult::NO_RESOURCES_AVAILABLE); } handle_send_next_command(); LOG_WARN("Command rejected"); } void LeSignallingManager::OnConnectionParameterUpdateRequest( SignalId signal_id, uint16_t interval_min, uint16_t interval_max, uint16_t peripheral_latency, uint16_t timeout_multiplier) { if (link_->GetRole() == hci::Role::PERIPHERAL) { LOG_WARN("Received request from LL central"); auto builder = LeCommandRejectNotUnderstoodBuilder::Create(signal_id.Value()); enqueue_buffer_->Enqueue(std::move(builder), handler_); return; } if (!link_->CheckConnectionParameters(interval_min, interval_max, peripheral_latency, timeout_multiplier)) { LOG_WARN("Received invalid connection parameter update request from LL central"); auto builder = ConnectionParameterUpdateResponseBuilder::Create(signal_id.Value(), ConnectionParameterUpdateResponseResult::REJECTED); enqueue_buffer_->Enqueue(std::move(builder), handler_); return; } link_->UpdateConnectionParameterFromRemote( signal_id, interval_min, interval_max, peripheral_latency, timeout_multiplier); } void LeSignallingManager::OnConnectionParameterUpdateResponse(SignalId signal_id, ConnectionParameterUpdateResponseResult result) { if (signal_id != command_just_sent_.signal_id_) { LOG_WARN("Unexpected response: no pending request"); return; } if (command_just_sent_.command_code_ != LeCommandCode::CONNECTION_PARAMETER_UPDATE_REQUEST) { LOG_WARN("Unexpected response: no pending request"); return; } alarm_.Cancel(); command_just_sent_.signal_id_ = kInitialSignalId; if (result != ConnectionParameterUpdateResponseResult::ACCEPTED) { LOG_ERROR("Connection parameter update is not accepted"); } } void LeSignallingManager::OnConnectionRequest(SignalId signal_id, Psm psm, Cid remote_cid, Mtu mtu, uint16_t mps, uint16_t initial_credits) { if (remote_cid == kInvalidCid) { LOG_WARN("Invalid remote cid received from remote psm:%d remote_cid:%d", psm, remote_cid); send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::INVALID_SOURCE_CID); return; } if (channel_allocator_->IsPsmUsed(psm)) { LOG_WARN("Psm already exists"); send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::LE_PSM_NOT_SUPPORTED); return; } if (!dynamic_service_manager_->IsServiceRegistered(psm)) { LOG_INFO("Service for this psm (%d) is not registered", psm); send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::LE_PSM_NOT_SUPPORTED); return; } PendingConnection pending{ .remote_cid = remote_cid, .incoming_signal_id = signal_id, .initial_credits = initial_credits, .max_pdu_size = mps, .mtu = mtu, }; dynamic_service_manager_->GetSecurityEnforcementInterface()->Enforce( link_->GetDevice(), dynamic_service_manager_->GetService(psm)->GetSecurityPolicy(), handler_->BindOnceOn(this, &LeSignallingManager::on_security_result_for_incoming, psm, pending)); } void LeSignallingManager::on_security_result_for_incoming(Psm psm, PendingConnection request, bool result) { auto signal_id = request.incoming_signal_id; auto* service = dynamic_service_manager_->GetService(psm); if (!result) { auto security_policy = service->GetSecurityPolicy(); switch (security_policy) { case SecurityPolicy::NO_SECURITY_WHATSOEVER_PLAINTEXT_TRANSPORT_OK: LOG_ERROR("If no security requirement, we should never fail"); break; case SecurityPolicy::ENCRYPTED_TRANSPORT: send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::INSUFFICIENT_AUTHENTICATION); return; case SecurityPolicy::AUTHENTICATED_ENCRYPTED_TRANSPORT: case SecurityPolicy::BEST: send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::INSUFFICIENT_AUTHENTICATION); return; case SecurityPolicy::_NOT_FOR_YOU__AUTHENTICATED_PAIRING_WITH_128_BIT_KEY: send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::INSUFFICIENT_ENCRYPTION_KEY_SIZE); return; case SecurityPolicy::_NOT_FOR_YOU__AUTHORIZATION: send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::INSUFFICIENT_AUTHORIZATION); return; } } auto config = service->GetConfigOption(); auto local_mtu = config.mtu; auto local_mps = link_->GetMps(); auto new_channel = link_->AllocateDynamicChannel(psm, request.remote_cid); if (new_channel == nullptr) { LOG_WARN("Can't allocate dynamic channel"); // TODO: We need to respond with the correct reason send_connection_response(signal_id, kInvalidCid, 0, 0, 0, LeCreditBasedConnectionResponseResult::SOURCE_CID_ALREADY_ALLOCATED); return; } send_connection_response(signal_id, new_channel->GetCid(), local_mtu, local_mps, link_->GetInitialCredit(), LeCreditBasedConnectionResponseResult::SUCCESS); auto* data_controller = reinterpret_cast( data_pipeline_manager_->GetDataController(new_channel->GetCid())); auto actual_mtu = std::min(request.mtu, local_mtu); data_controller->SetMtu(actual_mtu); data_controller->SetMps(std::min(request.max_pdu_size, local_mps)); data_controller->OnCredit(request.initial_credits); auto user_channel = std::make_unique(new_channel, handler_, link_, actual_mtu); dynamic_service_manager_->GetService(psm)->NotifyChannelCreation(std::move(user_channel)); } void LeSignallingManager::OnConnectionResponse(SignalId signal_id, Cid remote_cid, Mtu mtu, uint16_t mps, uint16_t initial_credits, LeCreditBasedConnectionResponseResult result) { if (signal_id != command_just_sent_.signal_id_) { LOG_WARN("Unexpected response: no pending request"); return; } if (command_just_sent_.command_code_ != LeCommandCode::LE_CREDIT_BASED_CONNECTION_REQUEST) { LOG_WARN("Unexpected response: no pending request"); return; } alarm_.Cancel(); command_just_sent_.signal_id_ = kInitialSignalId; if (result != LeCreditBasedConnectionResponseResult::SUCCESS) { LOG_WARN("Connection failed: %s", LeCreditBasedConnectionResponseResultText(result).data()); link_->OnOutgoingConnectionRequestFail(command_just_sent_.source_cid_, result); handle_send_next_command(); return; } auto new_channel = link_->AllocateReservedDynamicChannel(command_just_sent_.source_cid_, command_just_sent_.psm_, remote_cid); if (new_channel == nullptr) { LOG_WARN("Can't allocate dynamic channel"); link_->OnOutgoingConnectionRequestFail(command_just_sent_.source_cid_, LeCreditBasedConnectionResponseResult::NO_RESOURCES_AVAILABLE); handle_send_next_command(); return; } auto* data_controller = reinterpret_cast( data_pipeline_manager_->GetDataController(new_channel->GetCid())); auto actual_mtu = std::min(mtu, command_just_sent_.mtu_); data_controller->SetMtu(actual_mtu); data_controller->SetMps(std::min(mps, command_just_sent_.mps_)); data_controller->OnCredit(initial_credits); std::unique_ptr user_channel = std::make_unique(new_channel, handler_, link_, actual_mtu); link_->NotifyChannelCreation(new_channel->GetCid(), std::move(user_channel)); } void LeSignallingManager::OnDisconnectionRequest(SignalId signal_id, Cid cid, Cid remote_cid) { auto channel = channel_allocator_->FindChannelByCid(cid); if (channel == nullptr) { LOG_WARN("Disconnect request for an unknown channel"); return; } if (channel->GetRemoteCid() != remote_cid) { LOG_WARN("Disconnect request for an unmatching channel"); return; } auto builder = LeDisconnectionResponseBuilder::Create(signal_id.Value(), cid, remote_cid); enqueue_buffer_->Enqueue(std::move(builder), handler_); channel->OnClosed(hci::ErrorCode::SUCCESS); link_->FreeDynamicChannel(cid); } void LeSignallingManager::OnDisconnectionResponse(SignalId signal_id, Cid remote_cid, Cid cid) { if (signal_id != command_just_sent_.signal_id_ || command_just_sent_.command_code_ != LeCommandCode::DISCONNECTION_REQUEST) { LOG_WARN("Unexpected response: no pending request"); return; } if (command_just_sent_.source_cid_ != cid || command_just_sent_.destination_cid_ != remote_cid) { LOG_WARN("Unexpected response: cid doesn't match. Expected scid %d dcid %d, got scid %d dcid %d", command_just_sent_.source_cid_, command_just_sent_.destination_cid_, cid, remote_cid); handle_send_next_command(); return; } alarm_.Cancel(); command_just_sent_.signal_id_ = kInitialSignalId; auto channel = channel_allocator_->FindChannelByCid(cid); if (channel == nullptr) { LOG_WARN("Disconnect response for an unknown channel"); handle_send_next_command(); return; } channel->OnClosed(hci::ErrorCode::SUCCESS); link_->FreeDynamicChannel(cid); handle_send_next_command(); } void LeSignallingManager::OnCredit(Cid remote_cid, uint16_t credits) { auto channel = channel_allocator_->FindChannelByRemoteCid(remote_cid); if (channel == nullptr) { LOG_WARN("Received credit for invalid cid %d", channel->GetCid()); return; } auto* data_controller = reinterpret_cast( data_pipeline_manager_->GetDataController(channel->GetCid())); data_controller->OnCredit(credits); } void LeSignallingManager::on_incoming_packet() { auto packet = signalling_channel_->GetQueueUpEnd()->TryDequeue(); LeControlView control_packet_view = LeControlView::Create(*packet); if (!control_packet_view.IsValid()) { LOG_WARN("Invalid signalling packet received"); return; } auto code = control_packet_view.GetCode(); switch (code) { case LeCommandCode::COMMAND_REJECT: { LeCommandRejectView command_reject_view = LeCommandRejectView::Create(control_packet_view); if (!command_reject_view.IsValid()) { return; } OnCommandReject(command_reject_view); return; } case LeCommandCode::CONNECTION_PARAMETER_UPDATE_REQUEST: { ConnectionParameterUpdateRequestView parameter_update_req_view = ConnectionParameterUpdateRequestView::Create(control_packet_view); if (!parameter_update_req_view.IsValid()) { return; } OnConnectionParameterUpdateRequest( parameter_update_req_view.GetIdentifier(), parameter_update_req_view.GetIntervalMin(), parameter_update_req_view.GetIntervalMax(), parameter_update_req_view.GetPeripheralLatency(), parameter_update_req_view.GetTimeoutMultiplier()); return; } case LeCommandCode::CONNECTION_PARAMETER_UPDATE_RESPONSE: { ConnectionParameterUpdateResponseView parameter_update_rsp_view = ConnectionParameterUpdateResponseView::Create(control_packet_view); if (!parameter_update_rsp_view.IsValid()) { return; } OnConnectionParameterUpdateResponse(parameter_update_rsp_view.GetIdentifier(), parameter_update_rsp_view.GetResult()); return; } case LeCommandCode::LE_CREDIT_BASED_CONNECTION_REQUEST: { LeCreditBasedConnectionRequestView connection_request_view = LeCreditBasedConnectionRequestView::Create(control_packet_view); if (!connection_request_view.IsValid()) { return; } OnConnectionRequest(connection_request_view.GetIdentifier(), connection_request_view.GetLePsm(), connection_request_view.GetSourceCid(), connection_request_view.GetMtu(), connection_request_view.GetMps(), connection_request_view.GetInitialCredits()); return; } case LeCommandCode::LE_CREDIT_BASED_CONNECTION_RESPONSE: { LeCreditBasedConnectionResponseView connection_response_view = LeCreditBasedConnectionResponseView::Create(control_packet_view); if (!connection_response_view.IsValid()) { return; } OnConnectionResponse(connection_response_view.GetIdentifier(), connection_response_view.GetDestinationCid(), connection_response_view.GetMtu(), connection_response_view.GetMps(), connection_response_view.GetInitialCredits(), connection_response_view.GetResult()); return; } case LeCommandCode::LE_FLOW_CONTROL_CREDIT: { LeFlowControlCreditView credit_view = LeFlowControlCreditView::Create(control_packet_view); if (!credit_view.IsValid()) { return; } OnCredit(credit_view.GetCid(), credit_view.GetCredits()); return; } case LeCommandCode::DISCONNECTION_REQUEST: { LeDisconnectionRequestView disconnection_request_view = LeDisconnectionRequestView::Create(control_packet_view); if (!disconnection_request_view.IsValid()) { return; } OnDisconnectionRequest(disconnection_request_view.GetIdentifier(), disconnection_request_view.GetDestinationCid(), disconnection_request_view.GetSourceCid()); return; } case LeCommandCode::DISCONNECTION_RESPONSE: { LeDisconnectionResponseView disconnection_response_view = LeDisconnectionResponseView::Create(control_packet_view); if (!disconnection_response_view.IsValid()) { return; } OnDisconnectionResponse(disconnection_response_view.GetIdentifier(), disconnection_response_view.GetDestinationCid(), disconnection_response_view.GetSourceCid()); return; } case LeCommandCode::CREDIT_BASED_CONNECTION_REQUEST: { LeEnhancedCreditBasedConnectionRequestView request_view = LeEnhancedCreditBasedConnectionRequestView::Create(control_packet_view); if (!request_view.IsValid()) { return; } return; } case LeCommandCode::CREDIT_BASED_CONNECTION_RESPONSE: { LeEnhancedCreditBasedConnectionResponseView response_view = LeEnhancedCreditBasedConnectionResponseView::Create(control_packet_view); if (!response_view.IsValid()) { return; } return; } case LeCommandCode::CREDIT_BASED_RECONFIGURE_REQUEST: { LeEnhancedCreditBasedReconfigureRequestView request_view = LeEnhancedCreditBasedReconfigureRequestView::Create(control_packet_view); if (!request_view.IsValid()) { return; } return; } case LeCommandCode::CREDIT_BASED_RECONFIGURE_RESPONSE: { LeEnhancedCreditBasedReconfigureResponseView response_view = LeEnhancedCreditBasedReconfigureResponseView::Create(control_packet_view); if (!response_view.IsValid()) { return; } return; } default: LOG_WARN("Unhandled event 0x%x", static_cast(code)); auto builder = LeCommandRejectNotUnderstoodBuilder::Create(control_packet_view.GetIdentifier()); enqueue_buffer_->Enqueue(std::move(builder), handler_); return; } } void LeSignallingManager::send_connection_response(SignalId signal_id, Cid local_cid, Mtu mtu, uint16_t mps, uint16_t initial_credit, LeCreditBasedConnectionResponseResult result) { auto builder = LeCreditBasedConnectionResponseBuilder::Create(signal_id.Value(), local_cid, mtu, mps, initial_credit, result); enqueue_buffer_->Enqueue(std::move(builder), handler_); } void LeSignallingManager::on_command_timeout() { LOG_WARN("Response time out"); if (command_just_sent_.signal_id_ == kInvalidSignalId) { LOG_ERROR("No pending command"); return; } switch (command_just_sent_.command_code_) { case LeCommandCode::CONNECTION_PARAMETER_UPDATE_REQUEST: { link_->OnOutgoingConnectionRequestFail(command_just_sent_.source_cid_, LeCreditBasedConnectionResponseResult::NO_RESOURCES_AVAILABLE); break; } default: break; } handle_send_next_command(); } void LeSignallingManager::handle_send_next_command() { command_just_sent_.signal_id_ = kInvalidSignalId; if (pending_commands_.empty()) { return; } command_just_sent_ = pending_commands_.front(); pending_commands_.pop(); switch (command_just_sent_.command_code_) { case LeCommandCode::LE_CREDIT_BASED_CONNECTION_REQUEST: { auto builder = LeCreditBasedConnectionRequestBuilder::Create( command_just_sent_.signal_id_.Value(), command_just_sent_.psm_, command_just_sent_.source_cid_, command_just_sent_.mtu_, command_just_sent_.mps_, command_just_sent_.credits_); enqueue_buffer_->Enqueue(std::move(builder), handler_); alarm_.Schedule(common::BindOnce(&LeSignallingManager::on_command_timeout, common::Unretained(this)), kTimeout); break; } case LeCommandCode::DISCONNECTION_REQUEST: { auto builder = LeDisconnectionRequestBuilder::Create( command_just_sent_.signal_id_.Value(), command_just_sent_.destination_cid_, command_just_sent_.source_cid_); enqueue_buffer_->Enqueue(std::move(builder), handler_); alarm_.Schedule(common::BindOnce(&LeSignallingManager::on_command_timeout, common::Unretained(this)), kTimeout); break; } case LeCommandCode::CONNECTION_PARAMETER_UPDATE_REQUEST: { auto builder = ConnectionParameterUpdateRequestBuilder::Create( command_just_sent_.signal_id_.Value(), command_just_sent_.interval_min_, command_just_sent_.interval_max_, command_just_sent_.peripheral_latency_, command_just_sent_.timeout_multiplier_); enqueue_buffer_->Enqueue(std::move(builder), handler_); alarm_.Schedule(common::BindOnce(&LeSignallingManager::on_command_timeout, common::Unretained(this)), kTimeout); break; } default: { LOG_WARN("Unsupported command code 0x%x", static_cast(command_just_sent_.command_code_)); } } } } // namespace internal } // namespace le } // namespace l2cap } // namespace bluetooth