xref: /btstack/src/classic/rfcomm.h (revision 457b5cb16b95dcfdb3b5786e4195d8b5b211dd71)

/*
 * 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
 * [email protected]
 *
 */

/*
 *  RFCOMM.h
 */

#ifndef __RFCOMM_H
#define __RFCOMM_H

#include "utils.h"

#include <stdint.h>

#if defined __cplusplus
extern "C" {
#endif

#define UNLIMITED_INCOMING_CREDITS 0xff

#define RFCOMM_TEST_DATA_MAX_LEN 4

#define RFCOMM_RLS_STATUS_INVALID 0xff

// Line Status
#define LINE_STATUS_NO_ERROR       0x00
#define LINE_STATUS_OVERRUN_ERROR  0x03
#define LINE_STATUS_PARITY_ERORR   0x05
#define LINE_STATUS_FRAMING_ERROR  0x09

// Modem Status Flags
#define MODEM_STATUS_FC   0x02
#define MODEM_STATUS_RTC  0x04
#define MODEM_STATUS_RTR  0x08
#define MODEM_STATUS_IC   0x40
#define MODEM_STATUS_DV   0x80

typedef enum rpn_baud {
    RPN_BAUD_2400 = 0,
    RPN_BAUD_4800,
    RPN_BAUD_7200,
    RPN_BAUD_9600,
    RPN_BAUD_19200,
    RPN_BAUD_38400,
    RPN_BAUD_57600,
    RPN_BAUD_115200,
    RPN_BAUD_230400
} rpn_baud_t;

typedef enum rpn_data_bits {
    RPN_DATA_BITS_5 = 0,
    RPN_DATA_BITS_6 = 0,
    RPN_DATA_BITS_7 = 0,
    RPN_DATA_BITS_8 = 0
} rpn_data_bits_t;

typedef enum rpn_stop_bits {
    RPN_STOP_BITS_1_0 = 0,
    RPN_STOP_BITS_1_5
} rpn_stop_bits_t;

typedef enum rpn_parity {
    RPN_PARITY_NONE  = 0,
    RPN_PARITY_ODD   = 1,
    RPN_PARITY_EVEN  = 3,
    RPN_PARITY_MARK  = 5,
    RPN_PARITY_SPACE = 7,
} rpn_parity_t;

typedef enum rpn_flow_control {
    RPN_FLOW_CONTROL_XONXOFF_ON_INPUT  = 1 << 0,
    RPN_FLOW_CONTROL_XONXOFF_ON_OUTPUT = 1 << 1,
    RPN_FLOW_CONTROL_RTR_ON_INPUT  = 1 << 2,
    RPN_FLOW_CONTROL_RTR_ON_OUTPUT = 1 << 3,
    RPN_FLOW_CONTROL_RTC_ON_INPUT  = 1 << 4,
    RPN_FLOW_CONTROL_RTC_ON_OUTPUT = 1 << 5,
} rpn_flow_control_t;

#define RPN_PARAM_MASK_0_BAUD             0x01
#define RPN_PARAM_MASK_0_DATA_BITS        0x02
#define RPN_PARAM_MASK_0_STOP_BITS        0x04
#define RPN_PARAM_MASK_0_PARITY           0x08
#define RPN_PARAM_MASK_0_PARITY_TYPE      0x10
#define RPN_PARAM_MASK_0_XON_CHAR         0x20
#define RPN_PARAM_MASK_0_XOFF_CHAR        0x40
#define RPN_PARAM_MASK_0_RESERVED         0x80

// @note: values are identical to rpn_flow_control_t
#define RPN_PARAM_MASK_1_XONOFF_ON_INPUT  0x01
#define RPN_PARAM_MASK_1_XONOFF_ON_OUTPUT 0x02
#define RPN_PARAM_MASK_1_RTR_ON_INPUT     0x04
#define RPN_PARAM_MASK_1_RTR_ON_OUTPUT    0x08
#define RPN_PARAM_MASK_1_RTC_ON_INPUT     0x10
#define RPN_PARAM_MASK_1_RTC_ON_OUTPUT    0x20
#define RPN_PARAM_MASK_1_RESERVED_0       0x40
#define RPN_PARAM_MASK_1_RESERVED_1       0x80


// private structs
typedef enum {
	RFCOMM_MULTIPLEXER_CLOSED = 1,
	RFCOMM_MULTIPLEXER_W4_CONNECT,  // outgoing
	RFCOMM_MULTIPLEXER_SEND_SABM_0,     //    "
	RFCOMM_MULTIPLEXER_W4_UA_0,     //    "
	RFCOMM_MULTIPLEXER_W4_SABM_0,   // incoming
    RFCOMM_MULTIPLEXER_SEND_UA_0,
	RFCOMM_MULTIPLEXER_OPEN,
    RFCOMM_MULTIPLEXER_SEND_UA_0_AND_DISC
} RFCOMM_MULTIPLEXER_STATE;

typedef enum {
    MULT_EV_READY_TO_SEND = 1,

} RFCOMM_MULTIPLEXER_EVENT;

typedef enum {
	RFCOMM_CHANNEL_CLOSED = 1,
	RFCOMM_CHANNEL_W4_MULTIPLEXER,
	RFCOMM_CHANNEL_SEND_UIH_PN,
    RFCOMM_CHANNEL_W4_PN_RSP,
	RFCOMM_CHANNEL_SEND_SABM_W4_UA,
	RFCOMM_CHANNEL_W4_UA,
    RFCOMM_CHANNEL_INCOMING_SETUP,
    RFCOMM_CHANNEL_DLC_SETUP,
	RFCOMM_CHANNEL_OPEN,
    RFCOMM_CHANNEL_SEND_UA_AFTER_DISC,
    RFCOMM_CHANNEL_SEND_DISC,
    RFCOMM_CHANNEL_W4_UA_AFTER_UA,
    RFCOMM_CHANNEL_SEND_DM,

} RFCOMM_CHANNEL_STATE;

typedef enum {
    RFCOMM_CHANNEL_STATE_VAR_NONE            = 0,
    RFCOMM_CHANNEL_STATE_VAR_CLIENT_ACCEPTED = 1 << 0,
    RFCOMM_CHANNEL_STATE_VAR_RCVD_PN         = 1 << 1,
    RFCOMM_CHANNEL_STATE_VAR_RCVD_RPN        = 1 << 2,
    RFCOMM_CHANNEL_STATE_VAR_RCVD_SABM       = 1 << 3,

    RFCOMM_CHANNEL_STATE_VAR_RCVD_MSC_CMD    = 1 << 4,
    RFCOMM_CHANNEL_STATE_VAR_RCVD_MSC_RSP    = 1 << 5,
    RFCOMM_CHANNEL_STATE_VAR_SEND_PN_RSP     = 1 << 6,
    RFCOMM_CHANNEL_STATE_VAR_SEND_RPN_INFO   = 1 << 7,

    RFCOMM_CHANNEL_STATE_VAR_SEND_RPN_RSP    = 1 << 8,
    RFCOMM_CHANNEL_STATE_VAR_SEND_UA         = 1 << 9,
    RFCOMM_CHANNEL_STATE_VAR_SEND_MSC_CMD    = 1 << 10,
    RFCOMM_CHANNEL_STATE_VAR_SEND_MSC_RSP    = 1 << 11,

    RFCOMM_CHANNEL_STATE_VAR_SEND_CREDITS    = 1 << 12,
    RFCOMM_CHANNEL_STATE_VAR_SENT_MSC_CMD    = 1 << 13,
    RFCOMM_CHANNEL_STATE_VAR_SENT_MSC_RSP    = 1 << 14,
    RFCOMM_CHANNEL_STATE_VAR_SENT_CREDITS    = 1 << 15,
} RFCOMM_CHANNEL_STATE_VAR;

typedef enum {
    CH_EVT_RCVD_SABM = 1,
    CH_EVT_RCVD_UA,
    CH_EVT_RCVD_PN,
    CH_EVT_RCVD_PN_RSP,
    CH_EVT_RCVD_DISC,
    CH_EVT_RCVD_DM,
    CH_EVT_RCVD_MSC_CMD,
    CH_EVT_RCVD_MSC_RSP,
    CH_EVT_RCVD_NSC_RSP,
    CH_EVT_RCVD_RLS_CMD,
    CH_EVT_RCVD_RLS_RSP,
    CH_EVT_RCVD_RPN_CMD,
    CH_EVT_RCVD_RPN_REQ,
    CH_EVT_RCVD_CREDITS,
    CH_EVT_MULTIPLEXER_READY,
    CH_EVT_READY_TO_SEND,
} RFCOMM_CHANNEL_EVENT;

typedef struct rfcomm_channel_event {
    RFCOMM_CHANNEL_EVENT type;
    uint16_t dummy; // force rfcomm_channel_event to be 2-byte aligned -> avoid -Wcast-align warning
} rfcomm_channel_event_t;

typedef struct rfcomm_channel_event_pn {
    rfcomm_channel_event_t super;
    uint16_t max_frame_size;
    uint8_t  priority;
    uint8_t  credits_outgoing;
} rfcomm_channel_event_pn_t;

typedef struct rfcomm_rpn_data {
    uint8_t baud_rate;
    uint8_t flags;
    uint8_t flow_control;
    uint8_t xon;
    uint8_t xoff;
    uint8_t parameter_mask_0;   // first byte
    uint8_t parameter_mask_1;   // second byte
} rfcomm_rpn_data_t;

typedef struct rfcomm_channel_event_rpn {
    rfcomm_channel_event_t super;
    rfcomm_rpn_data_t data;
} rfcomm_channel_event_rpn_t;

typedef struct rfcomm_channel_event_rls {
    rfcomm_channel_event_t super;
    uint8_t line_status;
} rfcomm_channel_event_rls_t;

typedef struct rfcomm_channel_event_msc {
    rfcomm_channel_event_t super;
    uint8_t modem_status;
} rfcomm_channel_event_msc_t;

// info regarding potential connections
typedef struct {
    // linked list - assert: first field
    linked_item_t    item;

    // server channel
    uint8_t server_channel;

    // incoming max frame size
    uint16_t max_frame_size;

    // use incoming flow control
    uint8_t incoming_flow_control;

    // initial incoming credits
    uint8_t incoming_initial_credits;

    // client connection
    void *connection;

    // internal connection
    btstack_packet_handler_t packet_handler;

} rfcomm_service_t;

// info regarding multiplexer
// note: spec mandates single multiplexer per device combination
typedef struct {
    // linked list - assert: first field
    linked_item_t    item;

    timer_source_t   timer;
    int              timer_active;

	RFCOMM_MULTIPLEXER_STATE state;

    uint16_t  l2cap_cid;
    uint8_t   l2cap_credits;

    uint8_t   fcon; // only send if fcon & 1, send rsp if fcon & 0x80

	bd_addr_t remote_addr;
    hci_con_handle_t con_handle;

	uint8_t   outgoing;

    // hack to deal with authentication failure only observed by remote side
    uint8_t at_least_one_connection;

    uint16_t max_frame_size;

    // send DM for DLCI != 0
    uint8_t send_dm_for_dlci;

    // non supported command, 0 if not set
    uint8_t nsc_command;

    // test data - limited to RFCOMM_TEST_DATA_MAX_LEN
    uint8_t test_data_len;
    uint8_t test_data[RFCOMM_TEST_DATA_MAX_LEN];

} rfcomm_multiplexer_t;

// info regarding an actual connection
typedef struct {
    // linked list - assert: first field
    linked_item_t    item;

	rfcomm_multiplexer_t *multiplexer;
	uint16_t rfcomm_cid;
    uint8_t  outgoing;
    uint8_t  dlci;

    // number of packets granted to client
    uint8_t packets_granted;

    // credits for outgoing traffic
    uint8_t credits_outgoing;

    // number of packets remote will be granted
    uint8_t new_credits_incoming;

    // credits for incoming traffic
    uint8_t credits_incoming;

    // use incoming flow control
    uint8_t incoming_flow_control;

    // channel state
    RFCOMM_CHANNEL_STATE state;

    // state variables used in RFCOMM_CHANNEL_INCOMING
    RFCOMM_CHANNEL_STATE_VAR state_var;

    // priority set by incoming side in PN
    uint8_t pn_priority;

	// negotiated frame size
    uint16_t max_frame_size;

    // local rpn data
    rfcomm_rpn_data_t rpn_data;

    // rls line status. RFCOMM_RLS_STATUS_INVALID if not set
    uint8_t rls_line_status;

    // msc modem status.
    uint8_t msc_modem_status;

	// server channel (see rfcomm_service_t) - NULL => outgoing channel
	rfcomm_service_t * service;

    // internal connection
    btstack_packet_handler_t packet_handler;

    // client connection
    void * connection;

} rfcomm_channel_t;

/* API_START */

/**
 * @brief Set up RFCOMM.
 */
void rfcomm_init(void);

/**
 * @brief Set security level required for incoming connections, need to be called before registering services.
 */
void rfcomm_set_required_security_level(gap_security_level_t security_level);

/**
 * @brief Register packet handler.
 */
void rfcomm_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size));

/*
 * @brief Create RFCOMM connection to a given server channel on a remote deivce.
 * This channel will automatically provide enough credits to the remote side.
 * @param addr
 * @param server_channel
 * @param out_cid
 * @result status
 */
uint8_t rfcomm_create_channel(bd_addr_t addr, uint8_t server_channel, uint16_t * out_cid);

/*
 * @brief Create RFCOMM connection to a given server channel on a remote deivce.
 * This channel will use explicit credit management. During channel establishment, an initial  amount of credits is provided.
 * @param addr
 * @param server_channel
 * @param initial_credits
 * @param out_cid
 * @result status
 */
uint8_t rfcomm_create_channel_with_initial_credits(bd_addr_t addr, uint8_t server_channel, uint8_t initial_credits, uint16_t * out_cid);

/**
 * @brief Disconnects RFCOMM channel with given identifier.
 */
void rfcomm_disconnect_internal(uint16_t rfcomm_cid);

/**
 * @brief Registers RFCOMM service for a server channel and a maximum frame size, and assigns a packet handler. On embedded systems, use NULL for connection parameter. This channel provides automatically enough credits to the remote side.
 */
uint8_t rfcomm_register_service(uint8_t channel, uint16_t max_frame_size);

/**
 * @brief Registers RFCOMM service for a server channel and a maximum frame size, and assigns a packet handler. On embedded systems, use NULL for connection parameter. This channel will use explicit credit management. During channel establishment, an initial amount of credits is provided.
 */
uint8_t rfcomm_register_service_with_initial_credits(uint8_t channel, uint16_t max_frame_size, uint8_t initial_credits);

/**
 * @brief Unregister RFCOMM service.
 */
void rfcomm_unregister_service(uint8_t service_channel);

/**
 * @brief Accepts/Deny incoming RFCOMM connection.
 */
void rfcomm_accept_connection_internal(uint16_t rfcomm_cid);
void rfcomm_decline_connection_internal(uint16_t rfcomm_cid);

/**
 * @brief Grant more incoming credits to the remote side for the given RFCOMM channel identifier.
 */
void rfcomm_grant_credits(uint16_t rfcomm_cid, uint8_t credits);

/**
 * @brief Checks if RFCOMM can send packet. Returns yes if packet can be sent.
 */
int rfcomm_can_send_packet_now(uint16_t rfcomm_cid);

/**
 * @brief Sends RFCOMM data packet to the RFCOMM channel with given identifier.
 */
int  rfcomm_send_internal(uint16_t rfcomm_cid, uint8_t *data, uint16_t len);

/**
 * @brief Sends Local Line Status, see LINE_STATUS_..
 */
int rfcomm_send_local_line_status(uint16_t rfcomm_cid, uint8_t line_status);

/**
 * @brief Send local modem status. see MODEM_STAUS_..
 */
int rfcomm_send_modem_status(uint16_t rfcomm_cid, uint8_t modem_status);

/**
 * @brief Configure remote port
 */
int rfcomm_send_port_configuration(uint16_t rfcomm_cid, rpn_baud_t baud_rate, rpn_data_bits_t data_bits, rpn_stop_bits_t stop_bits, rpn_parity_t parity, rpn_flow_control_t flow_control);

/**
 * @brief Query remote port
 */
int rfcomm_query_port_configuration(uint16_t rfcomm_cid);

/**
 * @brief Allow to create RFCOMM packet in outgoing buffer.
 */
int       rfcomm_reserve_packet_buffer(void);
void      rfcomm_release_packet_buffer(void);
uint8_t * rfcomm_get_outgoing_buffer(void);
uint16_t  rfcomm_get_max_frame_size(uint16_t rfcomm_cid);
int       rfcomm_send_prepared(uint16_t rfcomm_cid, uint16_t len);
/* API_END */

#if defined __cplusplus
}
#endif

#endif // __RFCOMM_H