| /* |
| * Copyright 2021 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. |
| */ |
| |
| #pragma once |
| |
| #include <cstdint> |
| #include <functional> |
| #include <optional> |
| |
| #include "hci/address.h" |
| |
| namespace rootcanal { |
| |
| using ::bluetooth::hci::Address; |
| using TaskId = uint32_t; |
| |
| /* |
| * Notes about SCO / eSCO connection establishment: |
| * |
| * - Connections will always be established if possible as eSCO connections. |
| * The LMP parameter negotiation is skipped, instead the required parameters |
| * are directly sent to the peer. |
| * |
| * - If an synchronous connection setup fails with eSCO parameter negotiation, |
| * it is _not_ retried with SCO parameter negotiation. |
| * |
| * - If the parameters are compatible with the values returned from |
| * HCI Accept Synchronous Connection Request on the peer, |
| * the peer selects a valid link configuration which it returns |
| * in response. |
| */ |
| |
| struct ScoLinkParameters { |
| uint8_t transmission_interval; |
| uint8_t retransmission_window; |
| uint16_t rx_packet_length; |
| uint16_t tx_packet_length; |
| uint8_t air_mode; |
| bool extended; |
| }; |
| |
| struct ScoConnectionParameters { |
| uint32_t transmit_bandwidth; |
| uint32_t receive_bandwidth; |
| uint16_t max_latency; // 0-3 reserved, 0xFFFF = don't care |
| uint16_t voice_setting; |
| uint8_t retransmission_effort; |
| uint16_t packet_type; |
| |
| // Return true if packet_type enables extended SCO packets. |
| bool IsExtended() const; |
| |
| // Return the link parameters for these connection parameters, if the |
| // parameters are coherent, none otherwise. |
| std::optional<ScoLinkParameters> GetLinkParameters() const; |
| }; |
| |
| enum ScoState { |
| SCO_STATE_CLOSED = 0, |
| SCO_STATE_PENDING, |
| SCO_STATE_SENT_ESCO_CONNECTION_REQUEST, |
| SCO_STATE_SENT_SCO_CONNECTION_REQUEST, |
| SCO_STATE_OPENED, |
| }; |
| |
| enum ScoDatapath { |
| NORMAL = 0, // data is provided by the host over HCI |
| SPOOFED = 1, // rootcanal generates data itself |
| }; |
| |
| class ScoConnection { |
| public: |
| ScoConnection(Address address, ScoConnectionParameters const& parameters, |
| ScoState state, ScoDatapath datapath, bool legacy) |
| : address_(address), |
| parameters_(parameters), |
| link_parameters_(), |
| state_(state), |
| datapath_(datapath), |
| legacy_(legacy) {} |
| |
| ~ScoConnection(); |
| |
| bool IsLegacy() const { return legacy_; } |
| Address GetAddress() const { return address_; } |
| ScoState GetState() const { return state_; } |
| void SetState(ScoState state) { state_ = state; } |
| |
| void StartStream(std::function<TaskId()> startStream); |
| void StopStream(std::function<void(TaskId)> stopStream); |
| |
| ScoConnectionParameters GetConnectionParameters() const { |
| return parameters_; |
| } |
| ScoLinkParameters GetLinkParameters() const { return link_parameters_; } |
| void SetLinkParameters(ScoLinkParameters const& parameters) { |
| link_parameters_ = parameters; |
| } |
| |
| // Negotiate the connection parameters. |
| // Update the local connection parameters with negotiated values. |
| // Return true if the negotiation was successful, false otherwise. |
| bool NegotiateLinkParameters(ScoConnectionParameters const& peer); |
| |
| ScoDatapath GetDatapath() const { return datapath_; } |
| |
| private: |
| Address address_; |
| ScoConnectionParameters parameters_; |
| ScoLinkParameters link_parameters_; |
| ScoState state_; |
| |
| // whether we use HCI, spoof the data, or potential future datapaths |
| ScoDatapath datapath_; |
| |
| // The handle of the async task managing the SCO stream, used to simulate |
| // offloaded input. None if HCI is used for input packets. |
| std::optional<TaskId> stream_handle_{}; |
| |
| // Mark connections opened with the HCI command Add SCO Connection. |
| // The connection status is reported with HCI Connection Complete event |
| // rather than HCI Synchronous Connection Complete event. |
| bool legacy_; |
| }; |
| |
| } // namespace rootcanal |