/* * Copyright (C) 2014 BlueKitchen GmbH * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * 4. Any redistribution, use, or modification is done solely for * personal benefit and not for any commercial purpose or for * monetary gain. * * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Please inquire about commercial licensing options at * contact@bluekitchen-gmbh.com * */ /* * l2cap.h * * Logical Link Control and Adaption Protocol (L2CAP) * * Created by Matthias Ringwald on 5/16/09. */ #ifndef __L2CAP_H #define __L2CAP_H #include "hci.h" #include "l2cap_signaling.h" #include "btstack_util.h" #include "bluetooth.h" #if defined __cplusplus extern "C" { #endif // check L2CAP MTU #ifdef ENABLE_CLASSIC #if (L2CAP_HEADER_SIZE + L2CAP_MINIMAL_MTU) > HCI_ACL_PAYLOAD_SIZE #error "HCI_ACL_PAYLOAD_SIZE too small for minimal L2CAP MTU of 48 bytes" #endif #endif #ifdef ENABLE_BLE #if (L2CAP_HEADER_SIZE + L2CAP_LE_DEFAULT_MTU) > HCI_ACL_PAYLOAD_SIZE #error "HCI_ACL_PAYLOAD_SIZE too small for minimal L2CAP LE MTU of 23 bytes" #endif #endif #define L2CAP_LE_AUTOMATIC_CREDITS 0xffff // private structs typedef enum { L2CAP_STATE_CLOSED = 1, // no baseband L2CAP_STATE_WILL_SEND_CREATE_CONNECTION, L2CAP_STATE_WAIT_CONNECTION_COMPLETE, L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES, L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE, L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE, L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES, // only for Enhanced Retransmission Mode L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES, // only for Enhanced Retransmission Mode L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT, L2CAP_STATE_WAIT_CONNECT_RSP, // from peer L2CAP_STATE_CONFIG, L2CAP_STATE_OPEN, L2CAP_STATE_WAIT_DISCONNECT, // from application L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST, L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY, L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE, L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT, L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST, L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE, L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST, L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE, L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT, L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE, L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD, L2CAP_STATE_INVALID, } L2CAP_STATE; typedef enum { L2CAP_CHANNEL_STATE_VAR_NONE = 0, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ = 1 << 0, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP = 1 << 1, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ = 1 << 2, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP = 1 << 3, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ = 1 << 4, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP = 1 << 5, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU = 1 << 6, // in CONF RSP, add MTU field L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT = 1 << 7, // in CONF RSP, set CONTINUE flag L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID = 1 << 8, // in CONF RSP, send UNKNOWN OPTIONS L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED = 1 << 9, // in CONF RSP, send Unacceptable Parameters (ERTM) L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED = 1 << 10, // set when ERTM was requested but we want only Basic mode (ERM) L2CAP_CHANNEL_STATE_VAR_SEND_CMD_REJ_UNKNOWN = 1 << 11, // send CMD_REJ with reason unknown L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND = 1 << 12, // send Connection Respond with pending L2CAP_CHANNEL_STATE_VAR_INCOMING = 1 << 15, // channel is incoming } L2CAP_CHANNEL_STATE_VAR; typedef enum { L2CAP_CHANNEL_TYPE_CLASSIC, // Classic Basic or ERTM L2CAP_CHANNEL_TYPE_CONNECTIONLESS, // Classic Connectionless L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL, // LE L2CAP_CHANNEL_TYPE_LE_FIXED, // LE ATT + SM } l2cap_channel_type_t; typedef struct { l2cap_segmentation_and_reassembly_t sar; uint16_t len; uint8_t valid; } l2cap_ertm_rx_packet_state_t; typedef struct { l2cap_segmentation_and_reassembly_t sar; uint16_t len; uint8_t tx_seq; uint8_t retry_count; uint8_t retransmission_requested; } l2cap_ertm_tx_packet_state_t; typedef struct { // If not mandatory, the use of ERTM can be decided by the remote uint8_t ertm_mandatory; // Number of retransmissions that L2CAP is allowed to try before accepting that a packet and the channel is lost. uint8_t max_transmit; // time before retransmission of i-frame / Recommended : 2000 ms (ACL Flush timeout not used) uint16_t retransmission_timeout_ms; // time after withc s-frames are sent / Recommended: 12000 ms (ACL Flush timeout not used) uint16_t monitor_timeout_ms; // MTU for incoming SDUs uint16_t local_mtu; // Number of buffers for outgoing data uint8_t num_tx_buffers; // Number of packets that can be received out of order (-> our tx_window size) uint8_t num_rx_buffers; } l2cap_ertm_config_t; // info regarding an actual channel // note: l2cap_fixed_channel and l2cap_channel_t share commmon fields typedef struct l2cap_fixed_channel { // linked list - assert: first field btstack_linked_item_t item; // channel type l2cap_channel_type_t channel_type; // local cid, primary key for channel lookup uint16_t local_cid; // packet handler btstack_packet_handler_t packet_handler; // send request uint8_t waiting_for_can_send_now; // -- end of shared prefix } l2cap_fixed_channel_t; typedef struct { // linked list - assert: first field btstack_linked_item_t item; // channel type l2cap_channel_type_t channel_type; // local cid, primary key for channel lookup uint16_t local_cid; // packet handler btstack_packet_handler_t packet_handler; // send request uint8_t waiting_for_can_send_now; // -- end of shared prefix // timer btstack_timer_source_t rtx; // also used for ertx L2CAP_STATE state; L2CAP_CHANNEL_STATE_VAR state_var; // info hci_con_handle_t con_handle; bd_addr_t address; bd_addr_type_t address_type; uint8_t remote_sig_id; // used by other side, needed for delayed response uint8_t local_sig_id; // own signaling identifier uint16_t remote_cid; uint16_t local_mtu; uint16_t remote_mtu; uint16_t flush_timeout; // default 0xffff uint16_t psm; gap_security_level_t required_security_level; uint8_t reason; // used in decline internal // LE Data Channels // incoming SDU uint8_t * receive_sdu_buffer; uint16_t receive_sdu_len; uint16_t receive_sdu_pos; // outgoing SDU uint8_t * send_sdu_buffer; uint16_t send_sdu_len; uint16_t send_sdu_pos; // max PDU size uint16_t remote_mps; // credits for outgoing traffic uint16_t credits_outgoing; // number of packets remote will be granted uint16_t new_credits_incoming; // credits for incoming traffic uint16_t credits_incoming; // automatic credits incoming uint16_t automatic_credits; #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE // l2cap channel mode: basic or enhanced retransmission mode l2cap_channel_mode_t mode; // local mps = size of rx/tx buffers uint16_t local_mps; // retransmission timer btstack_timer_source_t retransmission_timer; // monitor timer btstack_timer_source_t monitor_timer; // local/remote config options uint16_t local_retransmission_timeout_ms; uint16_t local_monitor_timeout_ms; uint16_t remote_retransmission_timeout_ms; uint16_t remote_monitor_timeout_ms; uint8_t remote_tx_window_size; uint8_t local_max_transmit; uint8_t remote_max_transmit; // if ertm is not mandatory, allow fallback to L2CAP Basic Mode - flag uint8_t ertm_mandatory; // Frame Chech Sequence (crc16) is present in both directions uint8_t fcs_option; // sender: max num of stored outgoing frames uint8_t num_tx_buffers; // sender: number of unacknowledeged I-Frames - frames have been sent, but not acknowledged yet uint8_t unacked_frames; // sender: buffer index of oldest packet uint8_t tx_read_index; // sender: buffer index to store next tx packet uint8_t tx_write_index; // sender: buffer index of packet to send next uint8_t tx_send_index; // sender: next seq nr used for sending uint8_t next_tx_seq; // sender: selective retransmission requested uint8_t srej_active; // receiver: max num out-of-order packets // tx_window uint8_t num_rx_buffers; // receiver: buffer index of to store packet with delta = 1 uint8_t rx_store_index; // receiver: value of tx_seq in next expected i-frame uint8_t expected_tx_seq; // receiver: request transmission with tx_seq = req_seq and ack up to and including req_seq uint8_t req_seq; // receiver: local busy condition uint8_t local_busy; // receiver: send RR frame with optional final flag set - flag uint8_t send_supervisor_frame_receiver_ready; // receiver: send RR frame with poll bit set uint8_t send_supervisor_frame_receiver_ready_poll; // receiver: send RNR frame - flag uint8_t send_supervisor_frame_receiver_not_ready; // receiver: send REJ frame - flag uint8_t send_supervisor_frame_reject; // receiver: send SREJ frame - flag uint8_t send_supervisor_frame_selective_reject; // set final bit after poll packet with poll bit was received uint8_t set_final_bit_after_packet_with_poll_bit_set; // receiver: meta data for out-of-order frames l2cap_ertm_rx_packet_state_t * rx_packets_state; // sender: retransmission state l2cap_ertm_tx_packet_state_t * tx_packets_state; // receiver: reassemly pos uint16_t reassembly_pos; // receiver: reassemly sdu length uint16_t reassembly_sdu_length; // receiver: eassembly buffer uint8_t * reassembly_buffer; // receiver: num_rx_buffers of size local_mps uint8_t * rx_packets_data; // sender: num_tx_buffers of size local_mps uint8_t * tx_packets_data; #endif } l2cap_channel_t; // info regarding potential connections typedef struct { // linked list - assert: first field btstack_linked_item_t item; // service id uint16_t psm; // incoming MTU uint16_t mtu; // internal connection btstack_packet_handler_t packet_handler; // required security level gap_security_level_t required_security_level; } l2cap_service_t; typedef struct l2cap_signaling_response { hci_con_handle_t handle; uint8_t sig_id; uint8_t code; uint16_t cid; // source cid for CONNECTION REQUEST uint16_t data; // infoType for INFORMATION REQUEST, result for CONNECTION REQUEST and COMMAND UNKNOWN } l2cap_signaling_response_t; void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id); int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id); void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id); int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len); int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len); // PTS Testing int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len); void l2cap_require_security_level_2_for_outgoing_sdp(void); // Used by RFCOMM - similar to l2cap_can-send_packet_now but does not check if outgoing buffer is reserved int l2cap_can_send_prepared_packet_now(uint16_t local_cid); /* API_START */ /** * @brief Set up L2CAP and register L2CAP with HCI layer. */ void l2cap_init(void); /** * @brief Registers packet handler for LE Connection Parameter Update events */ void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)); /** * @brief Get max MTU for Classic connections based on btstack configuration */ uint16_t l2cap_max_mtu(void); /** * @brief Get max MTU for LE connections based on btstack configuration */ uint16_t l2cap_max_le_mtu(void); /** * @brief Set the max MTU for LE connections, if not set l2cap_max_mtu() will be used. */ void l2cap_set_max_le_mtu(uint16_t max_mtu); /** * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. * @param packet_handler * @param address * @param psm * @param mtu * @param local_cid * @return status */ uint8_t l2cap_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid); /** * @brief Creates L2CAP channel to the PSM of a remote device with baseband address using Enhanced Retransmission Mode. * A new baseband connection will be initiated if necessary. * @param packet_handler * @param address * @param psm * @param ertm_config * @param buffer to store reassembled rx packet, out-of-order packets and unacknowledged outgoing packets with their tretransmission timers * @param size of buffer * @param local_cid * @return status */ uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, l2cap_ertm_config_t * ertm_contig, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid); /** * @brief Disconnects L2CAP channel with given identifier. */ void l2cap_disconnect(uint16_t local_cid, uint8_t reason); /** * @brief Queries the maximal transfer unit (MTU) for L2CAP channel with given identifier. */ uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid); /** * @brief Sends L2CAP data packet to the channel with given identifier. */ int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len); /** * @brief Registers L2CAP service with given PSM and MTU, and assigns a packet handler. */ uint8_t l2cap_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level); /** * @brief Unregisters L2CAP service with given PSM. */ uint8_t l2cap_unregister_service(uint16_t psm); /** * @brief Accepts incoming L2CAP connection. */ void l2cap_accept_connection(uint16_t local_cid); /** * @brief Accepts incoming L2CAP connection for Enhanced Retransmission Mode * @param local_cid * @param ertm_config * @param buffer to store reassembled rx packet, out-of-order packets and unacknowledged outgoing packets with their tretransmission timers * @param size of buffer * @return status */ uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_contig, uint8_t * buffer, uint32_t size); /** * @brief Deny incoming L2CAP connection. */ void l2cap_decline_connection(uint16_t local_cid); /** * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module */ int l2cap_can_send_packet_now(uint16_t local_cid); /** * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function * so packet handler should be ready to handle it * @param local_cid */ void l2cap_request_can_send_now_event(uint16_t local_cid); /** * @brief Reserve outgoing buffer */ int l2cap_reserve_packet_buffer(void); /** * @brief Get outgoing buffer and prepare data. */ uint8_t *l2cap_get_outgoing_buffer(void); /** * @brief Send L2CAP packet prepared in outgoing buffer to channel */ int l2cap_send_prepared(uint16_t local_cid, uint16_t len); /** * @brief Release outgoing buffer (only needed if l2cap_send_prepared is not called) */ void l2cap_release_packet_buffer(void); // // LE Connection Oriented Channels feature with the LE Credit Based Flow Control Mode == LE Data Channel // /** * @brief Register L2CAP LE Data Channel service * @note MTU and initial credits are specified in l2cap_le_accept_connection(..) call * @param packet_handler * @param psm * @param security_level */ uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level); /** * @brief Unregister L2CAP LE Data Channel service * @param psm */ uint8_t l2cap_le_unregister_service(uint16_t psm); /* * @brief Accept incoming LE Data Channel connection * @param local_cid L2CAP LE Data Channel Identifier * @param receive_buffer buffer used for reassembly of L2CAP LE Information Frames into service data unit (SDU) with given MTU * @param receive_buffer_size buffer size equals MTU * @param initial_credits Number of initial credits provided to peer or L2CAP_LE_AUTOMATIC_CREDITS to enable automatic credits */ uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits); /** * @brief Deny incoming LE Data Channel connection due to resource constraints * @param local_cid L2CAP LE Data Channel Identifier */ uint8_t l2cap_le_decline_connection(uint16_t local_cid); /** * @brief Create LE Data Channel * @param packet_handler Packet handler for this connection * @param con_handle ACL-LE HCI Connction Handle * @param psm Service PSM to connect to * @param receive_buffer buffer used for reassembly of L2CAP LE Information Frames into service data unit (SDU) with given MTU * @param receive_buffer_size buffer size equals MTU * @param initial_credits Number of initial credits provided to peer or L2CAP_LE_AUTOMATIC_CREDITS to enable automatic credits * @param security_level Minimum required security level * @param out_local_cid L2CAP LE Channel Identifier is stored here */ uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, uint16_t * out_local_cid); /** * @brief Provide credtis for LE Data Channel * @param local_cid L2CAP LE Data Channel Identifier * @param credits Number additional credits for peer */ uint8_t l2cap_le_provide_credits(uint16_t cid, uint16_t credits); /** * @brief Check if packet can be scheduled for transmission * @param local_cid L2CAP LE Data Channel Identifier */ int l2cap_le_can_send_now(uint16_t cid); /** * @brief Request emission of L2CAP_EVENT_LE_CAN_SEND_NOW as soon as possible * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function * so packet handler should be ready to handle it * @param local_cid L2CAP LE Data Channel Identifier */ uint8_t l2cap_le_request_can_send_now_event(uint16_t cid); /** * @brief Send data via LE Data Channel * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event * @param local_cid L2CAP LE Data Channel Identifier * @param data data to send * @param size data size */ uint8_t l2cap_le_send_data(uint16_t cid, uint8_t * data, uint16_t size); /** * @brief Disconnect from LE Data Channel * @param local_cid L2CAP LE Data Channel Identifier */ uint8_t l2cap_le_disconnect(uint16_t cid); /* API_END */ /** * @brief ERTM Set channel as busy. * @note Can be cleared by l2cap_ertm_set_ready * @param local_cid */ uint8_t l2cap_ertm_set_busy(uint16_t local_cid); /** * @brief ERTM Set channel as ready * @note Used after l2cap_ertm_set_busy * @param local_cid */ uint8_t l2cap_ertm_set_ready(uint16_t local_cid); #if defined __cplusplus } #endif #endif // __L2CAP_H