include/bluetooth/rfcomm.h

/** @file
 *  @brief Bluetooth RFCOMM handling
 */

/*
 * Copyright (c) 2015-2016 Intel Corporation
 *
 * 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 Intel Corporation nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT HOLDER 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.
 */
#ifndef __BT_RFCOMM_H
#define __BT_RFCOMM_H

/**
 * @brief RFCOMM
 * @defgroup bt_rfcomm RFCOMM
 * @ingroup bluetooth
 * @{
 */

#ifdef __cplusplus
extern "C" {
#endif

#include <bluetooth/log.h>
#include <bluetooth/buf.h>
#include <bluetooth/conn.h>

/* RFCOMM channels (1-31): pre-allocated for profiles to avoid conflicts */
enum {
	BT_RFCOMM_CHAN_HFP_HF = 1,
	BT_RFCOMM_CHAN_HFP_AG,
	BT_RFCOMM_CHAN_HSP_AG,
	BT_RFCOMM_CHAN_HSP_HS,
};

struct bt_rfcomm_dlc;

/** @brief RFCOMM DLC operations structure. */
struct bt_rfcomm_dlc_ops {
	/** DLC connected callback
	 *
	 *  If this callback is provided it will be called whenever the
	 *  connection completes.
	 *
	 *  @param dlc The dlc that has been connected
	 */
	void (*connected)(struct bt_rfcomm_dlc *dlc);

	/** DLC disconnected callback
	 *
	 *  If this callback is provided it will be called whenever the
	 *  dlc is disconnected, including when a connection gets
	 *  rejected or cancelled (both incoming and outgoing)
	 *
	 *  @param dlc The dlc that has been Disconnected
	 */
	void (*disconnected)(struct bt_rfcomm_dlc *dlc);

	/** DLC recv callback
	 *
	 *  @param dlc The dlc receiving data.
	 *  @param buf Buffer containing incoming data.
	 */
	void (*recv)(struct bt_rfcomm_dlc *dlc, struct net_buf *buf);
};

/** @brief RFCOMM DLC structure. */
struct bt_rfcomm_dlc {
	/* Queue for outgoing data */
	struct nano_fifo           tx_queue;

	/** TX credits */
	struct nano_sem            tx_credits;

	struct bt_rfcomm_session  *session;
	struct bt_rfcomm_dlc_ops  *ops;
	struct bt_rfcomm_dlc      *_next;

	uint16_t                   mtu;
	uint8_t                    dlci;
	uint8_t                    state;
	uint8_t                    rx_credit;
	bool                       initiator;

	/* Stack for TX fiber */
	BT_STACK(stack, 128);
};

struct bt_rfcomm_server {
	/** Server Channel */
	uint8_t channel;

	/** Server accept callback
	 *
	 *  This callback is called whenever a new incoming connection requires
	 *  authorization.
	 *
	 *  @param conn The connection that is requesting authorization
	 *  @param dlc Pointer to received the allocated dlc
	 *
	 *  @return 0 in case of success or negative value in case of error.
	 */
	int (*accept)(struct bt_conn *conn, struct bt_rfcomm_dlc **dlc);

	struct bt_rfcomm_server	*_next;
};

/** @brief Register RFCOMM server
 *
 *  Register RFCOMM server for a channel, each new connection is authorized
 *  using the accept() callback which in case of success shall allocate the dlc
 *  structure to be used by the new connection.
 *
 *  @param server Server structure.
 *
 *  @return 0 in case of success or negative value in case of error.
 */
int bt_rfcomm_server_register(struct bt_rfcomm_server *server);

/** @brief Send data to RFCOMM
 *
 *  Send data from buffer to the dlc. Length should be less than or equal to
 *  mtu.
 *
 *  @param dlc Dlc object.
 *  @param buf Data buffer.
 *
 *  @return Bytes sent in case of success or negative value in case of error.
 */
int bt_rfcomm_dlc_send(struct bt_rfcomm_dlc *dlc, struct net_buf *buf);

/** @brief Get the buffer from fifo after reserving head room for RFCOMM, L2CAP
 *  and ACL headers.
 *
 *  @param fifo Which FIFO to take the buffer from.
 *
 *  @return New buffer.
 */
struct net_buf *bt_rfcomm_create_pdu(struct nano_fifo *fifo);

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif /* __BT_RFCOMM_H */