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/*
* 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_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_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_CMD_REJ_UNKNOWN = 1 << 9, // send CMD_REJ with reason unknown
L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND = 1 << 10, // send Connection Respond with pending
L2CAP_CHANNEL_STATE_VAR_INCOMING = 1 << 15, // channel is incoming
} L2CAP_CHANNEL_STATE_VAR;
// info regarding an actual connection
typedef struct {
// linked list - assert: first field
btstack_linked_item_t item;
// packet handler
btstack_packet_handler_t packet_handler;
// 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 local_cid;
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
uint8_t waiting_for_can_send_now;
// 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;
} 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 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 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. On embedded systems, use NULL for connection parameter.
*/
uint8_t l2cap_unregister_service(uint16_t psm);
/**
* @brief Accepts incoming L2CAP connection.
*/
void l2cap_accept_connection(uint16_t local_cid);
/**
* @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 */
#if defined __cplusplus
}
#endif
#endif // __L2CAP_H
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