conn.h

/** @file
 *  @brief Bluetooth connection handling
 */

/*
 * Copyright (c) 2015-2016 Intel Corporation
 * Copyright (c) 2025 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_BLUETOOTH_CONN_H_
#define ZEPHYR_INCLUDE_BLUETOOTH_CONN_H_

/**
 * @brief Connection management
 * @defgroup bt_conn Connection management
 * @ingroup bluetooth
 * @{
 */

#include <stdbool.h>
#include <stdint.h>

#include <zephyr/bluetooth/addr.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/direction.h>
#include <zephyr/bluetooth/gap.h>
#include <zephyr/bluetooth/hci_types.h>
#include <zephyr/net_buf.h>
#include <zephyr/sys/iterable_sections.h>
#include <zephyr/sys/slist.h>
#include <zephyr/sys/util_macro.h>
#include <zephyr/toolchain.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @struct bt_conn
 * @brief Opaque type representing a connection to a remote device
 */
struct bt_conn;

/** Connection parameters for LE connections */
struct bt_le_conn_param {
	uint16_t interval_min;
	uint16_t interval_max;
	uint16_t latency;
	uint16_t timeout;
};

/** @brief Initialize connection parameters
 *
 *  @param int_min  Minimum Connection Interval (N * 1.25 ms)
 *  @param int_max  Maximum Connection Interval (N * 1.25 ms)
 *  @param lat      Connection Latency
 *  @param to       Supervision Timeout (N * 10 ms)
 */
#define BT_LE_CONN_PARAM_INIT(int_min, int_max, lat, to) \
{ \
	.interval_min = (int_min), \
	.interval_max = (int_max), \
	.latency = (lat), \
	.timeout = (to), \
}

/** Helper to declare connection parameters inline
 *
 *  @param int_min  Minimum Connection Interval (N * 1.25 ms)
 *  @param int_max  Maximum Connection Interval (N * 1.25 ms)
 *  @param lat      Connection Latency
 *  @param to       Supervision Timeout (N * 10 ms)
 */
#define BT_LE_CONN_PARAM(int_min, int_max, lat, to) \
	((struct bt_le_conn_param[]) { \
		BT_LE_CONN_PARAM_INIT(int_min, int_max, lat, to) \
	 })

/** Default LE connection parameters:
 *    Connection Interval: 30-50 ms
 *    Latency: 0
 *    Timeout: 4 s
 */
#define BT_LE_CONN_PARAM_DEFAULT                                                                   \
	BT_LE_CONN_PARAM(BT_GAP_INIT_CONN_INT_MIN, BT_GAP_INIT_CONN_INT_MAX, 0,                    \
			 BT_GAP_MS_TO_CONN_TIMEOUT(4000))

/** Connection PHY information for LE connections */
struct bt_conn_le_phy_info {
	uint8_t tx_phy; /** Connection transmit PHY */
	uint8_t rx_phy; /** Connection receive PHY */
};

/** Connection PHY options */
enum {
	/** Convenience value when no options are specified. */
	BT_CONN_LE_PHY_OPT_NONE = 0,

	/** LE Coded using S=2 coding preferred when transmitting. */
	BT_CONN_LE_PHY_OPT_CODED_S2  = BIT(0),

	/** LE Coded using S=8 coding preferred when transmitting. */
	BT_CONN_LE_PHY_OPT_CODED_S8  = BIT(1),
};

/** Preferred PHY parameters for LE connections */
struct bt_conn_le_phy_param {
	uint16_t options; /**< Connection PHY options. */
	uint8_t  pref_tx_phy; /**< Bitmask of preferred transmit PHYs */
	uint8_t  pref_rx_phy; /**< Bitmask of preferred receive PHYs */
};

/** Initialize PHY parameters
 *
 * @param _pref_tx_phy Bitmask of preferred transmit PHYs.
 * @param _pref_rx_phy Bitmask of preferred receive PHYs.
 */
#define BT_CONN_LE_PHY_PARAM_INIT(_pref_tx_phy, _pref_rx_phy) \
{ \
	.options = BT_CONN_LE_PHY_OPT_NONE, \
	.pref_tx_phy = (_pref_tx_phy), \
	.pref_rx_phy = (_pref_rx_phy), \
}

/** Helper to declare PHY parameters inline
 *
 * @param _pref_tx_phy Bitmask of preferred transmit PHYs.
 * @param _pref_rx_phy Bitmask of preferred receive PHYs.
 */
#define BT_CONN_LE_PHY_PARAM(_pref_tx_phy, _pref_rx_phy) \
	((struct bt_conn_le_phy_param []) { \
		BT_CONN_LE_PHY_PARAM_INIT(_pref_tx_phy, _pref_rx_phy) \
	 })

/** Only LE 1M PHY */
#define BT_CONN_LE_PHY_PARAM_1M BT_CONN_LE_PHY_PARAM(BT_GAP_LE_PHY_1M, \
						     BT_GAP_LE_PHY_1M)

/** Only LE 2M PHY */
#define BT_CONN_LE_PHY_PARAM_2M BT_CONN_LE_PHY_PARAM(BT_GAP_LE_PHY_2M, \
						     BT_GAP_LE_PHY_2M)

/** Only LE Coded PHY. */
#define BT_CONN_LE_PHY_PARAM_CODED BT_CONN_LE_PHY_PARAM(BT_GAP_LE_PHY_CODED, \
							BT_GAP_LE_PHY_CODED)

/** All LE PHYs. */
#define BT_CONN_LE_PHY_PARAM_ALL BT_CONN_LE_PHY_PARAM(BT_GAP_LE_PHY_1M |   \
						      BT_GAP_LE_PHY_2M |   \
						      BT_GAP_LE_PHY_CODED, \
						      BT_GAP_LE_PHY_1M |   \
						      BT_GAP_LE_PHY_2M |   \
						      BT_GAP_LE_PHY_CODED)

/** Connection data length information for LE connections */
struct bt_conn_le_data_len_info {
	/** Maximum Link Layer transmission payload size in bytes. */
	uint16_t tx_max_len;
	/** Maximum Link Layer transmission payload time in us. */
	uint16_t tx_max_time;
	/** Maximum Link Layer reception payload size in bytes. */
	uint16_t rx_max_len;
	/** Maximum Link Layer reception payload time in us. */
	uint16_t rx_max_time;
};

/** Connection data length parameters for LE connections */
struct bt_conn_le_data_len_param {
	/** Maximum Link Layer transmission payload size in bytes. */
	uint16_t tx_max_len;
	/** Maximum Link Layer transmission payload time in us. */
	uint16_t tx_max_time;
};

/** Initialize transmit data length parameters
 *
 * @param  _tx_max_len  Maximum Link Layer transmission payload size in bytes.
 * @param  _tx_max_time Maximum Link Layer transmission payload time in us.
 */
#define BT_CONN_LE_DATA_LEN_PARAM_INIT(_tx_max_len, _tx_max_time) \
{ \
	.tx_max_len = (_tx_max_len), \
	.tx_max_time = (_tx_max_time), \
}

/** Helper to declare transmit data length parameters inline
 *
 * @param  _tx_max_len  Maximum Link Layer transmission payload size in bytes.
 * @param  _tx_max_time Maximum Link Layer transmission payload time in us.
 */
#define BT_CONN_LE_DATA_LEN_PARAM(_tx_max_len, _tx_max_time) \
	((struct bt_conn_le_data_len_param[]) { \
		BT_CONN_LE_DATA_LEN_PARAM_INIT(_tx_max_len, _tx_max_time) \
	 })

/** Default LE data length parameters. */
#define BT_LE_DATA_LEN_PARAM_DEFAULT \
	BT_CONN_LE_DATA_LEN_PARAM(BT_GAP_DATA_LEN_DEFAULT, \
				  BT_GAP_DATA_TIME_DEFAULT)

/** Maximum LE data length parameters. */
#define BT_LE_DATA_LEN_PARAM_MAX \
	BT_CONN_LE_DATA_LEN_PARAM(BT_GAP_DATA_LEN_MAX, \
				  BT_GAP_DATA_TIME_MAX)

/** Connection subrating parameters for LE connections */
struct bt_conn_le_subrate_param {
	/** Minimum subrate factor. */
	uint16_t subrate_min;
	/** Maximum subrate factor. */
	uint16_t subrate_max;
	/** Maximum Peripheral latency in units of subrated connection intervals. */
	uint16_t max_latency;
	/** Minimum number of underlying connection events to remain active
	 *  after a packet containing a Link Layer PDU with a non-zero Length
	 *  field is sent or received.
	 */
	uint16_t continuation_number;
	/** Connection Supervision timeout (N * 10 ms).
	 *  If using @ref bt_conn_le_subrate_set_defaults, this is the
	 *  maximum supervision timeout allowed in requests by a peripheral.
	 */
	uint16_t supervision_timeout;
};

/** Subrating information for LE connections */
struct bt_conn_le_subrating_info {
	/** Connection subrate factor. */
	uint16_t factor;
	/** Number of underlying connection events to remain active after
	 *  a packet containing a Link Layer PDU with a non-zero Length
	 *  field is sent or received.
	 */
	uint16_t continuation_number;
};

/** Updated subrating connection parameters for LE connections */
struct bt_conn_le_subrate_changed {
	/** HCI Status from LE Subrate Changed event.
	 *  The remaining parameters will be unchanged if status is not
	 *  BT_HCI_ERR_SUCCESS.
	 */
	uint8_t status;
	/** Connection subrate factor. */
	uint16_t factor;
	/** Number of underlying connection events to remain active after
	 *  a packet containing a Link Layer PDU with a non-zero Length
	 *  field is sent or received.
	 */
	uint16_t continuation_number;
	/** Peripheral latency in units of subrated connection intervals. */
	uint16_t peripheral_latency;
	/** Connection Supervision timeout (N * 10 ms). */
	uint16_t supervision_timeout;
};

/** @brief Maximum Connection Interval Groups possible
 *
 * The practical maximum is 41 groups based on HCI event size constraints:
 *     (HCI event max size - cmd_complete overhead - response fields) / sizeof(group)
 *     (255 - 4 - 3) / 6 = 41 groups max
 */
#define BT_CONN_LE_MAX_CONN_INTERVAL_GROUPS 41

/** @brief Minimum supported connection interval group
 *
 * Each group represents an arithmetic sequence of supported connection intervals:
 *   min, min + stride, min + 2 * stride, ..., min + n * stride (where min + n * stride <= max)
 *
 * Example: min = 10 (1250 us), max = 60 (7500 us), stride = 5 (625 us)
 *   -> Supported: 1250 us, 1875 us, 2500 us, ..., 6875 us, 7500 us
 */
struct bt_conn_le_min_conn_interval_group {
	/** @brief Lower bound of group interval range
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_INTERVAL_MIN_125US - @ref BT_HCI_LE_SCI_INTERVAL_MAX_125US
	 */
	uint16_t min_125us;
	/** @brief Upper bound of group interval range
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_INTERVAL_MIN_125US - @ref BT_HCI_LE_SCI_INTERVAL_MAX_125US
	 */
	uint16_t max_125us;
	/** @brief Increment between consecutive supported intervals
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_STRIDE_MIN_125US - @ref BT_HCI_LE_SCI_INTERVAL_MAX_125US
	 */
	uint16_t stride_125us;
};

/** Minimum supported connection interval information */
struct bt_conn_le_min_conn_interval_info {
	/** @brief Minimum supported connection interval
	 *
	 * Unit: microseconds
	 *
	 * Range: @ref BT_HCI_LE_MIN_SUPP_CONN_INT_MIN_US - @ref BT_HCI_LE_MIN_SUPP_CONN_INT_MAX_US
	 */
	uint16_t min_supported_conn_interval_us;
	/** @brief Number of interval groups.
	 *
	 * Range: 0 - @ref BT_CONN_LE_MAX_CONN_INTERVAL_GROUPS
	 *
	 * If zero, the controller only supports Rounded ConnInterval Values (RCV).
	 */
	uint8_t num_groups;
	/** @brief Array of supported connection interval groups.
	 *
	 * Multiple groups allow representing non-contiguous or differently-strided ranges.
	 */
	struct bt_conn_le_min_conn_interval_group groups[BT_CONN_LE_MAX_CONN_INTERVAL_GROUPS];
};

/** Connection rate parameters for LE connections */
struct bt_conn_le_conn_rate_param {
	/** @brief Minimum connection interval
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_INTERVAL_MIN_125US - @ref BT_HCI_LE_SCI_INTERVAL_MAX_125US
	 */
	uint16_t interval_min_125us;
	/** @brief Maximum connection interval
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_INTERVAL_MIN_125US - @ref BT_HCI_LE_SCI_INTERVAL_MAX_125US
	 */
	uint16_t interval_max_125us;
	/** @brief Minimum subrate factor
	 *
	 * Range: @ref BT_HCI_LE_SUBRATE_FACTOR_MIN - @ref BT_HCI_LE_SUBRATE_FACTOR_MAX
	 */
	uint16_t subrate_min;
	/** @brief Maximum subrate factor
	 *
	 * Range: @ref BT_HCI_LE_SUBRATE_FACTOR_MIN - @ref BT_HCI_LE_SUBRATE_FACTOR_MAX
	 */
	uint16_t subrate_max;
	/** @brief Maximum Peripheral latency
	 *
	 * Unit: subrated connection intervals @ref bt_conn_le_conn_rate_changed.subrate_factor
	 *
	 * Range: @ref BT_HCI_LE_PERIPHERAL_LATENCY_MIN - @ref BT_HCI_LE_PERIPHERAL_LATENCY_MAX
	 */
	uint16_t max_latency;
	/** @brief Minimum number of underlying connection events to remain active
	 *  after a packet containing a Link Layer PDU with a non-zero Length
	 *  field is sent or received.
	 *
	 * Range: @ref BT_HCI_LE_CONTINUATION_NUM_MIN - @ref BT_HCI_LE_CONTINUATION_NUM_MAX
	 */
	uint16_t continuation_number;
	/** @brief Connection Supervision timeout
	 *
	 * Unit: 10 milliseconds
	 *
	 * Range: @ref BT_HCI_LE_SUPERVISION_TIMEOUT_MIN - @ref BT_HCI_LE_SUPERVISION_TIMEOUT_MAX
	 */
	uint16_t supervision_timeout_10ms;
	/** @brief Minimum length of connection event
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_CE_LEN_MIN_125US - @ref BT_HCI_LE_SCI_CE_LEN_MAX_125US
	 */
	uint16_t min_ce_len_125us;
	/** @brief Maximum length of connection event
	 *
	 * Unit: 125 microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_CE_LEN_MIN_125US - @ref BT_HCI_LE_SCI_CE_LEN_MAX_125US
	 */
	uint16_t max_ce_len_125us;
};

/** Updated connection rate parameters */
struct bt_conn_le_conn_rate_changed {
	/** Connection interval
	 *
	 * Unit: microseconds
	 *
	 * Range: @ref BT_HCI_LE_SCI_INTERVAL_MIN_US - @ref BT_HCI_LE_SCI_INTERVAL_MAX_US
	 */
	uint32_t interval_us;
	/** Connection subrate factor
	 *
	 * Range: @ref BT_HCI_LE_SUBRATE_FACTOR_MIN - @ref BT_HCI_LE_SUBRATE_FACTOR_MAX
	 */
	uint16_t subrate_factor;
	/** Peripheral latency
	 *
	 * Unit: subrated connection intervals @ref bt_conn_le_conn_rate_changed.subrate_factor
	 *
	 * Range: @ref BT_HCI_LE_PERIPHERAL_LATENCY_MIN - @ref BT_HCI_LE_PERIPHERAL_LATENCY_MAX
	 */
	uint16_t peripheral_latency;
	/** Number of underlying connection events to remain active after
	 *  a packet containing a Link Layer PDU with a non-zero Length
	 *  field is sent or received.
	 *
	 * Range: @ref BT_HCI_LE_CONTINUATION_NUM_MIN - @ref BT_HCI_LE_CONTINUATION_NUM_MAX
	 */
	uint16_t continuation_number;
	/** Connection Supervision timeout
	 *
	 * Unit: 10 milliseconds
	 *
	 * Range: @ref BT_HCI_LE_SUPERVISION_TIMEOUT_MIN - @ref BT_HCI_LE_SUPERVISION_TIMEOUT_MAX
	 */
	uint16_t supervision_timeout_10ms;
};

/** Read all remote features complete callback params */
struct bt_conn_le_read_all_remote_feat_complete {
	/** @brief  HCI Status from LE Read All Remote Features Complete event.
	 *
	 *  The remaining parameters will be unchanged if status is not @ref BT_HCI_ERR_SUCCESS.
	 */
	uint8_t status;
	/** Number of pages supported by remote device. */
	uint8_t max_remote_page;
	/** Number of pages fetched from remote device. */
	uint8_t max_valid_page;
	/** @brief Pointer to array of size 248, with feature bits of remote supported features.
	 *
	 *  Page 0 being 8 bytes, with the following 10 pages of 24 bytes.
	 *  Refer to BT_LE_FEAT_BIT_* for values.
	 *  Refer to the BT_FEAT_LE_* macros for value comparison.
	 *  See Bluetooth Core Specification, Vol 6, Part B, Section 4.6.
	 */
	const uint8_t *features;
};

#define BT_CONN_LE_FRAME_SPACE_TYPES_MASK_ACL_IFS                    \
	(BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_IFS_ACL_CP_MASK | \
	 BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_IFS_ACL_PC_MASK)

#define BT_CONN_LE_FRAME_SPACE_TYPES_MASK_ACL                        \
	(BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_IFS_ACL_CP_MASK | \
	 BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_IFS_ACL_PC_MASK | \
	 BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_MCES_MASK)

#define BT_CONN_LE_FRAME_SPACE_TYPES_MASK_CIS                     \
	(BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_IFS_CIS_MASK | \
	 BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_MSS_CIS_MASK)

/** Maximum frame space in microseconds.
 *  As defined in Bluetooth Core Specification, Vol 4, Part E, Section 7.8.151.
 */
#define BT_CONN_LE_FRAME_SPACE_MAX (10000U)

/** Frame space update initiator. */
enum bt_conn_le_frame_space_update_initiator {
	/** Initiated by local host */
	BT_CONN_LE_FRAME_SPACE_UPDATE_INITIATOR_LOCAL_HOST =
		BT_HCI_LE_FRAME_SPACE_UPDATE_INITIATOR_LOCAL_HOST,
	/** Initiated by local controller */
	BT_CONN_LE_FRAME_SPACE_UPDATE_INITIATOR_LOCAL_CONTROLLER =
		BT_HCI_LE_FRAME_SPACE_UPDATE_INITIATOR_LOCAL_CONTROLLER,
	/** Initiated by peer */
	BT_CONN_LE_FRAME_SPACE_UPDATE_INITIATOR_PEER =
		BT_HCI_LE_FRAME_SPACE_UPDATE_INITIATOR_PEER
};

/** Frame space update params */
struct bt_conn_le_frame_space_update_param {
	/** Phy mask of the PHYs to be updated.
	 *  Refer to BT_HCI_LE_FRAME_SPACE_UPDATE_PHY_* for values.
	 */
	uint8_t phys;
	/** Spacing types mask of the spacing types to be updated.
	 *  Refer to BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_* and
	 *  BT_CONN_LE_FRAME_SPACE_TYPES_MASK_* for values.
	 */
	uint16_t spacing_types;
	/** Minimum frame space in microseconds.
	 *  Bluetooth Core Specification, Vol 4, Part E, Section 7.8.151
	 *  allows for a range of frame space from 0 to 10000 microseconds.
	 *  The actual supported frame space values will be dependent on
	 *  the controller's capabilities.
	 */
	uint16_t frame_space_min;
	/** Maximum frame space in microseconds.
	 *  Bluetooth Core Specification, Vol 4, Part E, Section 7.8.151
	 *  allows for a range of frame space from 0 to 10000 microseconds.
	 *  The actual supported frame space values will be dependent on
	 *  the controller's capabilities.
	 */
	uint16_t frame_space_max;
};

/** Frame space updated callback params */
struct bt_conn_le_frame_space_updated {
	/** HCI Status from LE Frame Space Update Complete event.
	 *  The remaining parameters will be invalid if status is not
	 *  @ref BT_HCI_ERR_SUCCESS.
	 */
	uint8_t status;
	/** Initiator of the frame space update. */
	enum bt_conn_le_frame_space_update_initiator initiator;
	/** Updated frame space in microseconds. */
	uint16_t frame_space;
	/** Phy mask of the PHYs updated.
	 *  Refer to BT_HCI_LE_FRAME_SPACE_UPDATE_PHY_* for values.
	 */
	uint8_t phys;
	/** Spacing types mask of the spacing types updated.
	 *  Refer to BT_HCI_LE_FRAME_SPACE_UPDATE_SPACING_TYPE_* and
	 *  BT_CONN_LE_FRAME_SPACE_TYPES_MASK_* for values.
	 */
	uint16_t spacing_types;
};

/** Connection Type */
enum __packed bt_conn_type {
	/** LE Connection Type */
	BT_CONN_TYPE_LE = BIT(0),
	/** BR/EDR Connection Type */
	BT_CONN_TYPE_BR = BIT(1),
	/** SCO Connection Type */
	BT_CONN_TYPE_SCO = BIT(2),
	/** ISO Connection Type */
	BT_CONN_TYPE_ISO = BIT(3),
	/** All Connection Type */
	BT_CONN_TYPE_ALL = BT_CONN_TYPE_LE | BT_CONN_TYPE_BR |
			   BT_CONN_TYPE_SCO | BT_CONN_TYPE_ISO,
};

/** Supported AA-Only RTT precision. */
enum bt_conn_le_cs_capability_rtt_aa_only {
	/** AA-Only RTT variant is not supported. */
	BT_CONN_LE_CS_RTT_AA_ONLY_NOT_SUPP = 0,
	/** 10ns time-of-flight accuracy. */
	BT_CONN_LE_CS_RTT_AA_ONLY_10NS,
	/** 150ns time-of-flight accuracy. */
	BT_CONN_LE_CS_RTT_AA_ONLY_150NS,
};

/** Supported Sounding Sequence RTT precision. */
enum bt_conn_le_cs_capability_rtt_sounding {
	/** Sounding Sequence RTT variant is not supported. */
	BT_CONN_LE_CS_RTT_SOUNDING_NOT_SUPP = 0,
	/** 10ns time-of-flight accuracy. */
	BT_CONN_LE_CS_RTT_SOUNDING_10NS,
	/** 150ns time-of-flight accuracy. */
	BT_CONN_LE_CS_RTT_SOUNDING_150NS,
};

/** Supported Random Payload RTT precision. */
enum bt_conn_le_cs_capability_rtt_random_payload {
	/** Random Payload RTT variant is not supported. */
	BT_CONN_LE_CS_RTT_RANDOM_PAYLOAD_NOT_SUPP = 0,
	/** 10ns time-of-flight accuracy. */
	BT_CONN_LE_CS_RTT_RANDOM_PAYLOAD_10NS,
	/** 150ns time-of-flight accuracy. */
	BT_CONN_LE_CS_RTT_RANDOM_PAYLOAD_150NS,
};

/** Remote channel sounding capabilities for LE connections supporting CS */
struct bt_conn_le_cs_capabilities {
	/** Number of CS configurations */
	uint8_t num_config_supported;
	/** Maximum number of consecutive CS procedures.
	 *
	 * When set to zero, indicates support for both fixed and indefinite
	 * numbers of CS procedures before termination.
	 */
	uint16_t max_consecutive_procedures_supported;
	/** Number of antennas. */
	uint8_t num_antennas_supported;
	/** Maximum number of antenna paths. */
	uint8_t max_antenna_paths_supported;
	/** Initiator role. */
	bool initiator_supported;
	/** Reflector role. */
	bool reflector_supported;
	/** Mode-3 */
	bool mode_3_supported;
	/** RTT AA-Only */
	enum bt_conn_le_cs_capability_rtt_aa_only rtt_aa_only_precision;
	/** RTT Sounding */
	enum bt_conn_le_cs_capability_rtt_sounding rtt_sounding_precision;
	/** RTT Random Payload */
	enum bt_conn_le_cs_capability_rtt_random_payload rtt_random_payload_precision;
	/** Number of CS steps needed to achieve the
	 * accuracy requirements for RTT AA Only.
	 *
	 * Set to 0 if RTT AA Only isn't supported.
	 */
	uint8_t rtt_aa_only_n;
	/** Number of CS steps needed to achieve the
	 * accuracy requirements for RTT Sounding.
	 *
	 * Set to 0 if RTT Sounding isn't supported
	 */
	uint8_t rtt_sounding_n;
	/** Number of CS steps needed to achieve the
	 * accuracy requirements for RTT Random Payload.
	 *
	 * Set to 0 if RTT Random Payload isn't supported.
	 */
	uint8_t rtt_random_payload_n;
	/** Phase-based normalized attack detector metric
	 * when a CS_SYNC with sounding sequence is received.
	 */
	bool phase_based_nadm_sounding_supported;
	/** Phase-based normalized attack detector metric
	 * when a CS_SYNC with random sequence is received.
	 */
	bool phase_based_nadm_random_supported;
	/** CS_SYNC LE 2M PHY. */
	bool cs_sync_2m_phy_supported;
	/** CS_SYNC LE 2M 2BT PHY. */
	bool cs_sync_2m_2bt_phy_supported;
	/** Subfeature: CS with no Frequency Actuation Error. */
	bool cs_without_fae_supported;
	/** Subfeature: Channel Selection Algorithm #3c */
	bool chsel_alg_3c_supported;
	/** Subfeature: Phase-based Ranging from RTT sounding sequence. */
	bool pbr_from_rtt_sounding_seq_supported;
	/** Subfeature: IPT in the CS reflector */
	bool cs_ipt_reflector;
	/** Optional T_IP1 time durations during CS steps.
	 *
	 *  - Bit 0: 10 us
	 *  - Bit 1: 20 us
	 *  - Bit 2: 30 us
	 *  - Bit 3: 40 us
	 *  - Bit 4: 50 us
	 *  - Bit 5: 60 us
	 *  - Bit 6: 80 us
	 */
	uint16_t t_ip1_times_supported;
	/** Optional T_IP2 time durations during CS steps.
	 *
	 *  - Bit 0: 10 us
	 *  - Bit 1: 20 us
	 *  - Bit 2: 30 us
	 *  - Bit 3: 40 us
	 *  - Bit 4: 50 us
	 *  - Bit 5: 60 us
	 *  - Bit 6: 80 us
	 */
	uint16_t t_ip2_times_supported;
	/** Optional T_FCS time durations during CS steps.
	 *
	 *  - Bit 0: 15 us
	 *  - Bit 1: 20 us
	 *  - Bit 2: 30 us
	 *  - Bit 3: 40 us
	 *  - Bit 4: 50 us
	 *  - Bit 5: 60 us
	 *  - Bit 6: 80 us
	 *  - Bit 7: 100 us
	 *  - Bit 8: 120 us
	 */
	uint16_t t_fcs_times_supported;
	/** Optional T_PM time durations during CS steps.
	 *
	 *  - Bit 0: 10 us
	 *  - Bit 1: 20 us
	 */
	uint16_t t_pm_times_supported;
	/** Time in microseconds for the antenna switch period of the CS tones. */
	uint8_t t_sw_time;
	/** Supported SNR levels used in RTT packets.
	 *
	 *  - Bit 0: 18dB
	 *  - Bit 1: 21dB
	 *  - Bit 2: 24dB
	 *  - Bit 3: 27dB
	 *  - Bit 4: 30dB
	 */
	uint8_t tx_snr_capability;
	/** Supported T_IP2_IPT time durations during CS steps.
	 *
	 *  - Bit 0: 10 us
	 *  - Bit 1: 20 us
	 *  - Bit 2: 30 us
	 *  - Bit 3: 40 us
	 *  - Bit 4: 50 us
	 *  - Bit 5: 60 us
	 *  - Bit 6: 80 us
	 */
	uint16_t t_ip2_ipt_times_supported;
	/** Supported time in microseconds for the antenna switch period of the
	 *  CS tones during IPT.
	 *
	 *  0x00, 0x01, 0x02, 0x04, or 0x0A - Time in microseconds for the
	 *  antenna switch period of the CS tones
	 */
	uint8_t t_sw_ipt_time_supported;
};

/** Remote FAE Table for LE connections supporting CS */
struct bt_conn_le_cs_fae_table {
	int8_t *remote_fae_table;
};

/** @brief Extract main mode part from @ref bt_conn_le_cs_mode
 *
 * @private
 *
 * @param x @ref bt_conn_le_cs_mode value
 * @retval 1 Matches @ref BT_HCI_OP_LE_CS_MAIN_MODE_1 (0x01)
 * @retval 2 Matches @ref BT_HCI_OP_LE_CS_MAIN_MODE_2 (0x02)
 * @retval 3 Matches @ref BT_HCI_OP_LE_CS_MAIN_MODE_3 (0x03)
 *
 * @note Returned values match the HCI main mode values.
 */
#define BT_CONN_LE_CS_MODE_MAIN_MODE_PART(x) ((x) & 0x3)

/** @brief Extract sub-mode part from @ref bt_conn_le_cs_mode
 *
 * @private
 *
 * @param x @ref bt_conn_le_cs_mode value
 * @retval 0 Internal encoding for @ref BT_HCI_OP_LE_CS_SUB_MODE_UNUSED (0xFF)
 * @retval 1 Matches @ref BT_HCI_OP_LE_CS_SUB_MODE_1 (0x01)
 * @retval 2 Matches @ref BT_HCI_OP_LE_CS_SUB_MODE_2 (0x02)
 * @retval 3 Matches @ref BT_HCI_OP_LE_CS_SUB_MODE_3 (0x03)
 *
 * @note The value 0 encodes HCI 0xFF. This allows @ref bt_conn_le_cs_mode to
 * fit in one byte. To obtain the HCI sub-mode value, use `(sub_mode == 0 ? 0xFF
 * : sub_mode)`, where `sub_mode` is the value returned by this macro.
 */
#define BT_CONN_LE_CS_MODE_SUB_MODE_PART(x)  (((x) >> 4) & 0x3)

/** @brief Channel sounding mode (main and sub-mode)
 *
 * Represents the combination of Channel Sounding (CS) main mode and sub-mode.
 *
 * @note The underlying numeric values are an internal encoding and are
 * not stable API. Do not assume a direct concatenation of HCI values
 * when inspecting the raw enum value.
 *
 * @sa BT_CONN_LE_CS_MODE_MAIN_MODE_PART
 * @sa BT_CONN_LE_CS_MODE_SUB_MODE_PART
 */
enum bt_conn_le_cs_mode {
	/** Main mode 1 (RTT), sub-mode: unused */
	BT_CONN_LE_CS_MAIN_MODE_1_NO_SUB_MODE = BT_HCI_OP_LE_CS_MAIN_MODE_1,
	/** Main mode 2 (PBR), sub-mode: unused */
	BT_CONN_LE_CS_MAIN_MODE_2_NO_SUB_MODE = BT_HCI_OP_LE_CS_MAIN_MODE_2,
	/** Main mode 3 (RTT and PBR), sub-mode: unused */
	BT_CONN_LE_CS_MAIN_MODE_3_NO_SUB_MODE = BT_HCI_OP_LE_CS_MAIN_MODE_3,
	/** Main mode 2 (PBR), sub-mode 1 (RTT) */
	BT_CONN_LE_CS_MAIN_MODE_2_SUB_MODE_1 = BT_HCI_OP_LE_CS_MAIN_MODE_2 |
					      (BT_HCI_OP_LE_CS_SUB_MODE_1 << 4),
	/** Main mode 2 (PBR), sub-mode 3 (RTT and PBR) */
	BT_CONN_LE_CS_MAIN_MODE_2_SUB_MODE_3 = BT_HCI_OP_LE_CS_MAIN_MODE_2 |
					      (BT_HCI_OP_LE_CS_SUB_MODE_3 << 4),
	/** Main mode 3 (RTT and PBR), sub-mode 2 (PBR) */
	BT_CONN_LE_CS_MAIN_MODE_3_SUB_MODE_2 = BT_HCI_OP_LE_CS_MAIN_MODE_3 |
					      (BT_HCI_OP_LE_CS_SUB_MODE_2 << 4),
};

/** Channel sounding role */
enum bt_conn_le_cs_role {
	/** CS initiator role */
	BT_CONN_LE_CS_ROLE_INITIATOR,
	/** CS reflector role */
	BT_CONN_LE_CS_ROLE_REFLECTOR,
};

/** Channel sounding RTT type */
enum bt_conn_le_cs_rtt_type {
	/** RTT AA only */
	BT_CONN_LE_CS_RTT_TYPE_AA_ONLY = BT_HCI_OP_LE_CS_RTT_TYPE_AA_ONLY,
	/** RTT with 32-bit sounding sequence */
	BT_CONN_LE_CS_RTT_TYPE_32_BIT_SOUNDING = BT_HCI_OP_LE_CS_RTT_TYPE_32BIT_SOUND,
	/** RTT with 96-bit sounding sequence */
	BT_CONN_LE_CS_RTT_TYPE_96_BIT_SOUNDING = BT_HCI_OP_LE_CS_RTT_TYPE_96BIT_SOUND,
	/** RTT with 32-bit random sequence */
	BT_CONN_LE_CS_RTT_TYPE_32_BIT_RANDOM = BT_HCI_OP_LE_CS_RTT_TYPE_32BIT_RAND,
	/** RTT with 64-bit random sequence */
	BT_CONN_LE_CS_RTT_TYPE_64_BIT_RANDOM = BT_HCI_OP_LE_CS_RTT_TYPE_64BIT_RAND,
	/** RTT with 96-bit random sequence */
	BT_CONN_LE_CS_RTT_TYPE_96_BIT_RANDOM = BT_HCI_OP_LE_CS_RTT_TYPE_96BIT_RAND,
	/** RTT with 128-bit random sequence */
	BT_CONN_LE_CS_RTT_TYPE_128_BIT_RANDOM = BT_HCI_OP_LE_CS_RTT_TYPE_128BIT_RAND,
};

/** Channel sounding PHY used for CS sync */
enum bt_conn_le_cs_sync_phy {
	/** LE 1M PHY */
	BT_CONN_LE_CS_SYNC_1M_PHY = BT_HCI_OP_LE_CS_CS_SYNC_1M,
	/** LE 2M PHY */
	BT_CONN_LE_CS_SYNC_2M_PHY = BT_HCI_OP_LE_CS_CS_SYNC_2M,
	/** LE 2M 2BT PHY */
	BT_CONN_LE_CS_SYNC_2M_2BT_PHY = BT_HCI_OP_LE_CS_CS_SYNC_2M_2BT,
};

/** Channel sounding channel selection type */
enum bt_conn_le_cs_chsel_type {
	/** Use Channel Selection Algorithm #3b for non-mode-0 CS steps */
	BT_CONN_LE_CS_CHSEL_TYPE_3B = BT_HCI_OP_LE_CS_TEST_CHSEL_TYPE_3B,
	/** Use Channel Selection Algorithm #3c for non-mode-0 CS steps */
	BT_CONN_LE_CS_CHSEL_TYPE_3C = BT_HCI_OP_LE_CS_TEST_CHSEL_TYPE_3C,
};

/** Channel sounding channel sequence shape */
enum bt_conn_le_cs_ch3c_shape {
	/** Use Hat shape for user-specified channel sequence */
	BT_CONN_LE_CS_CH3C_SHAPE_HAT = BT_HCI_OP_LE_CS_TEST_CH3C_SHAPE_HAT,
	/** Use X shape for user-specified channel sequence */
	BT_CONN_LE_CS_CH3C_SHAPE_X = BT_HCI_OP_LE_CS_TEST_CH3C_SHAPE_X,
};

/** Channel sounding configuration */
struct bt_conn_le_cs_config {
	/** CS configuration ID */
	uint8_t id;
	/** CS main and sub mode */
	enum bt_conn_le_cs_mode mode;
	/** Minimum number of CS main mode steps to be executed before a submode step is executed */
	uint8_t min_main_mode_steps;
	/** Maximum number of CS main mode steps to be executed before a submode step is executed */
	uint8_t max_main_mode_steps;
	/** Number of main mode steps taken from the end of the last CS subevent to be repeated
	 *  at the beginning of the current CS subevent directly after the last mode-0 step of that
	 *  event
	 */
	uint8_t main_mode_repetition;
	/** Number of CS mode-0 steps to be included at the beginning of each CS subevent */
	uint8_t mode_0_steps;
	/** CS role */
	enum bt_conn_le_cs_role role;
	/** RTT type */
	enum bt_conn_le_cs_rtt_type rtt_type;
	/** CS Sync PHY */
	enum bt_conn_le_cs_sync_phy cs_sync_phy;
	/** The number of times the Channel_Map field will be cycled through for non-mode-0 steps
	 *  within a CS procedure
	 */
	uint8_t channel_map_repetition;
	/** Channel selection type */
	enum bt_conn_le_cs_chsel_type channel_selection_type;
	/** User-specified channel sequence shape */
	enum bt_conn_le_cs_ch3c_shape ch3c_shape;
	/** Number of channels skipped in each rising and falling sequence  */
	uint8_t ch3c_jump;
	/** CS enhancements 1
	 *  Bit 0 - IPT is enabled in the CS reflector.
	 *  All other bits are reserved and shall be set to 0.
	 */
	uint8_t cs_enhancements_1;
	/** Interlude time in microseconds between the RTT packets */
	uint8_t t_ip1_time_us;
	/** Interlude time in microseconds between the CS tones */
	uint8_t t_ip2_time_us;
	/** Time in microseconds for frequency changes */
	uint8_t t_fcs_time_us;
	/** Time in microseconds for the phase measurement period of the CS tones */
	uint8_t t_pm_time_us;
	/** Channel map used for CS procedure
	 *  Channels n = 0, 1, 23, 24, 25, 77, and 78 are not allowed and shall be set to zero.
	 *  Channel 79 is reserved for future use and shall be set to zero.
	 *  At least 15 channels shall be enabled.
	 */
	uint8_t channel_map[10];
};

/** Procedure done status */
enum bt_conn_le_cs_procedure_done_status {
	BT_CONN_LE_CS_PROCEDURE_COMPLETE = BT_HCI_LE_CS_PROCEDURE_DONE_STATUS_COMPLETE,
	BT_CONN_LE_CS_PROCEDURE_INCOMPLETE = BT_HCI_LE_CS_PROCEDURE_DONE_STATUS_PARTIAL,
	BT_CONN_LE_CS_PROCEDURE_ABORTED = BT_HCI_LE_CS_PROCEDURE_DONE_STATUS_ABORTED,
};

/** Subevent done status */
enum bt_conn_le_cs_subevent_done_status {
	BT_CONN_LE_CS_SUBEVENT_COMPLETE = BT_HCI_LE_CS_SUBEVENT_DONE_STATUS_COMPLETE,
	BT_CONN_LE_CS_SUBEVENT_ABORTED = BT_HCI_LE_CS_SUBEVENT_DONE_STATUS_ABORTED,
};

/** Procedure abort reason */
enum bt_conn_le_cs_procedure_abort_reason {
	BT_CONN_LE_CS_PROCEDURE_NOT_ABORTED = BT_HCI_LE_CS_PROCEDURE_ABORT_REASON_NO_ABORT,
	BT_CONN_LE_CS_PROCEDURE_ABORT_REQUESTED =
		BT_HCI_LE_CS_PROCEDURE_ABORT_REASON_LOCAL_HOST_OR_REMOTE_REQUEST,
	BT_CONN_LE_CS_PROCEDURE_ABORT_TOO_FEW_CHANNELS =
		BT_HCI_LE_CS_PROCEDURE_ABORT_REASON_TOO_FEW_CHANNELS,
	BT_CONN_LE_CS_PROCEDURE_ABORT_CHMAP_INSTANT_PASSED =
		BT_HCI_LE_CS_PROCEDURE_ABORT_REASON_CHMAP_INSTANT_PASSED,
	BT_CONN_LE_CS_PROCEDURE_ABORT_UNSPECIFIED = BT_HCI_LE_CS_PROCEDURE_ABORT_REASON_UNSPECIFIED,
};

/** Subevent abort reason */
enum bt_conn_le_cs_subevent_abort_reason {
	BT_CONN_LE_CS_SUBEVENT_NOT_ABORTED = BT_HCI_LE_CS_SUBEVENT_ABORT_REASON_NO_ABORT,
	BT_CONN_LE_CS_SUBEVENT_ABORT_REQUESTED =
		BT_HCI_LE_CS_SUBEVENT_ABORT_REASON_LOCAL_HOST_OR_REMOTE_REQUEST,
	BT_CONN_LE_CS_SUBEVENT_ABORT_NO_CS_SYNC =
		BT_HCI_LE_CS_SUBEVENT_ABORT_REASON_NO_CS_SYNC_RECEIVED,
	BT_CONN_LE_CS_SUBEVENT_ABORT_SCHED_CONFLICT =
		BT_HCI_LE_CS_SUBEVENT_ABORT_REASON_SCHED_CONFLICT,
	BT_CONN_LE_CS_SUBEVENT_ABORT_UNSPECIFIED = BT_HCI_LE_CS_SUBEVENT_ABORT_REASON_UNSPECIFIED,
};

/** Subevent data for LE connections supporting CS */
struct bt_conn_le_cs_subevent_result {
	struct {
		/** CS configuration identifier.
		 *
		 *  Range: 0 to 3
		 *
		 *  If these results were generated by a CS Test,
		 *  this value will be set to 0 and has no meaning.
		 */
		uint8_t config_id;
		/** Starting ACL connection event counter.
		 *
		 *  If these results were generated by a CS Test,
		 *  this value will be set to 0 and has no meaning.
		 */
		uint16_t start_acl_conn_event;
		/** CS procedure count associated with these results.
		 *
		 *  This is the CS procedure count since the completion of
		 *  the Channel Sounding Security Start procedure.
		 */
		uint16_t procedure_counter;
		/** Frequency compensation value in units of 0.01 ppm.
		 *
		 *  This is a 15-bit signed integer in the range [-100, 100] ppm.
		 *
		 *  A value of @ref BT_HCI_LE_CS_SUBEVENT_RESULT_FREQ_COMPENSATION_NOT_AVAILABLE
		 *  indicates that the role is not the initiator, or that the
		 *  frequency compensation value is unavailable.
		 */
		uint16_t frequency_compensation;
		/** Reference power level in dBm.
		 *
		 *  Range: -127 to 20
		 *
		 *  A value of @ref BT_HCI_LE_CS_REF_POWER_LEVEL_UNAVAILABLE indicates
		 *  that the reference power level was not available during a subevent.
		 */
		int8_t reference_power_level;
		/** Procedure status. */
		enum bt_conn_le_cs_procedure_done_status procedure_done_status;
		/** Subevent status
		 *
		 *  For aborted subevents, this will be set to @ref BT_CONN_LE_CS_SUBEVENT_ABORTED
		 *  and abort_step will contain the step number on which the subevent was aborted.
		 *  Consider the following example:
		 *
		 *  subevent_done_status = @ref BT_CONN_LE_CS_SUBEVENT_ABORTED
		 *  num_steps_reported = 160
		 *  abort_step = 100
		 *
		 *  this would mean that steps from 0 to 99 are complete and steps from 100 to 159
		 *  are aborted.
		 */
		enum bt_conn_le_cs_subevent_done_status subevent_done_status;
		/** Abort reason.
		 *
		 *  If the procedure status is
		 *  @ref BT_CONN_LE_CS_PROCEDURE_ABORTED, this field will
		 *  specify the reason for the abortion.
		 */
		enum bt_conn_le_cs_procedure_abort_reason procedure_abort_reason;
		/** Abort reason.
		 *
		 *  If the subevent status is
		 *  @ref BT_CONN_LE_CS_SUBEVENT_ABORTED, this field will
		 *  specify the reason for the abortion.
		 */
		enum bt_conn_le_cs_subevent_abort_reason subevent_abort_reason;
		/** Number of antenna paths used during the phase measurement stage.
		 */
		uint8_t num_antenna_paths;
		/** Number of CS steps in the subevent.
		 */
		uint8_t num_steps_reported;
		/** Step number, on which the subevent was aborted
		 *  if subevent_done_status is @ref BT_CONN_LE_CS_SUBEVENT_COMPLETE
		 *  then abort_step will be unused and set to 255
		 */
		uint8_t abort_step;
	} header;
	/** Pointer to buffer containing step data.
	 *  NULL if num_steps_reported is 0.
	 */
	struct net_buf_simple *step_data_buf;
};

/** @brief Increment a connection's reference count.
 *
 *  Increment the reference count of a connection object.
 *
 *  @note Will return NULL if the reference count is zero.
 *
 *  @param conn Connection object.
 *
 *  @return Connection object with incremented reference count, or NULL if the
 *          reference count is zero.
 */
struct bt_conn *bt_conn_ref(struct bt_conn *conn);

/** @brief Decrement a connection's reference count.
 *
 *  Decrement the reference count of a connection object.
 *
 *  @param conn Connection object.
 */
void bt_conn_unref(struct bt_conn *conn);

/** @brief Iterate through all bt_conn objects.
 *
 * Iterates through all bt_conn objects that are alive in the Host allocator.
 *
 * To find established connections, combine this with @ref bt_conn_get_info.
 * Check that @ref bt_conn_info.state is @ref BT_CONN_STATE_CONNECTED.
 *
 * Thread safety: This API is thread safe, but it does not guarantee a
 * sequentially-consistent view for objects allocated during the current
 * invocation of this API. E.g. If preempted while allocations A then B then C
 * happen then results may include A and C but miss B.
 *
 * @param type  Connection Type
 * @param func  Function to call for each connection.
 * @param data  Data to pass to the callback function.
 */
void bt_conn_foreach(enum bt_conn_type type,
		     void (*func)(struct bt_conn *conn, void *data),
		     void *data);

/** @brief Look up an existing connection by address.
 *
 *  Look up an existing connection based on the remote address.
 *
 *  The caller gets a new reference to the connection object which must be
 *  released with bt_conn_unref() once done using the object.
 *
 *  @param id   Local identity (in most cases BT_ID_DEFAULT).
 *  @param peer Remote address.
 *
 *  @return Connection object or NULL if not found.
 */
struct bt_conn *bt_conn_lookup_addr_le(uint8_t id, const bt_addr_le_t *peer);

/** @brief Get destination (peer) address of a connection.
 *
 *  @param conn Connection object.
 *
 *  @return Destination address if @p conn is a valid @ref BT_CONN_TYPE_LE connection
 */
const bt_addr_le_t *bt_conn_get_dst(const struct bt_conn *conn);

/** @brief Get array index of a connection
 *
 *  This function is used to map bt_conn to index of an array of
 *  connections. The array has CONFIG_BT_MAX_CONN elements.
 *
 *  @param conn Connection object.
 *
 *  @return Index of the connection object.
 *          The range of the returned value is 0..CONFIG_BT_MAX_CONN-1
 */
uint8_t bt_conn_index(const struct bt_conn *conn);

/** LE Connection Info Structure */
struct bt_conn_le_info {
	/** Source (Local) Identity Address */
	const bt_addr_le_t *src;
	/** Destination (Remote) Identity Address or remote Resolvable Private
	 *  Address (RPA) before identity has been resolved.
	 */
	const bt_addr_le_t *dst;
	/** Local device address used during connection setup. */
	const bt_addr_le_t *local;
	/** Remote device address used during connection setup. */
	const bt_addr_le_t *remote;
	/** Connection interval in microseconds */
	uint32_t interval_us;
#if !defined(CONFIG_BT_SHORTER_CONNECTION_INTERVALS) || defined(__DOXYGEN__)
	union {
		/** @brief Connection interval in units of 1.25 ms
		 *
		 * @deprecated Use @ref bt_conn_le_info.interval_us instead
		 */
		__deprecated uint16_t interval;
		/** @cond INTERNAL_HIDDEN */
		/** Workaround for setting deprecated @ref bt_conn_le_info.interval */
		uint16_t _interval;
		/** @endcond */
	};
#endif /* !CONFIG_BT_SHORTER_CONNECTION_INTERVALS */

	uint16_t latency; /**< Connection peripheral latency */
	uint16_t timeout; /**< Connection supervision timeout */

#if defined(CONFIG_BT_USER_PHY_UPDATE)
	const struct bt_conn_le_phy_info      *phy;
#endif /* defined(CONFIG_BT_USER_PHY_UPDATE) */

#if defined(CONFIG_BT_USER_DATA_LEN_UPDATE)
	/* Connection maximum single fragment parameters */
	const struct bt_conn_le_data_len_info *data_len;
#endif /* defined(CONFIG_BT_USER_DATA_LEN_UPDATE) */

#if defined(CONFIG_BT_SUBRATING)
	/* Connection subrating parameters */
	const struct bt_conn_le_subrating_info *subrate;
#endif /* defined(CONFIG_BT_SUBRATING) */
};

/** @brief Convert connection interval to milliseconds
 *
 *  Multiply by 1.25 to get milliseconds.
 *
 *  Note that this may be inaccurate, as something like 7.5 ms cannot be
 *  accurately presented with integers.
 */
#define BT_CONN_INTERVAL_TO_MS(interval) ((interval) * 5U / 4U)

/** @brief Convert connection interval to microseconds
 *
 *  Multiply by 1250 to get microseconds.
 */
#define BT_CONN_INTERVAL_TO_US(interval) ((interval) * 1250U)

/** @brief Convert shorter connection interval to microseconds
 *
 *  Multiply by 125 to get microseconds.
 */
#define BT_CONN_SCI_INTERVAL_TO_US(_interval) ((_interval) * BT_HCI_LE_SCI_INTERVAL_UNIT_US)

/** BR/EDR Connection Info Structure */
struct bt_conn_br_info {
	const bt_addr_t *dst; /**< Destination (Remote) BR/EDR address */
};

/** SCO Connection Info Structure */
struct bt_conn_sco_info {
	uint8_t link_type; /**< SCO link type */
	uint8_t air_mode;  /**< SCO air mode (codec type) */
};

enum {
	BT_CONN_ROLE_CENTRAL = 0,
	BT_CONN_ROLE_PERIPHERAL = 1,
};

enum bt_conn_state {
	/** Channel disconnected */
	BT_CONN_STATE_DISCONNECTED,
	/** Channel in connecting state */
	BT_CONN_STATE_CONNECTING,
	/** Channel connected and ready for upper layer traffic on it */
	BT_CONN_STATE_CONNECTED,
	/** Channel in disconnecting state */
	BT_CONN_STATE_DISCONNECTING,
};

/** Security level. */
typedef enum __packed {
	/** Level 0: Only for BR/EDR special cases, like SDP */
	BT_SECURITY_L0,
	/** Level 1: No encryption and no authentication. */
	BT_SECURITY_L1,
	/** Level 2: Encryption and no authentication (no MITM). */
	BT_SECURITY_L2,
	/** Level 3: Encryption and authentication (MITM). */
	BT_SECURITY_L3,
	/** Level 4: Authenticated Secure Connections and 128-bit key. */
	BT_SECURITY_L4,
	/** Bit to force new pairing procedure, bit-wise OR with requested
	 *  security level.
	 */
	BT_SECURITY_FORCE_PAIR = BIT(7),
} bt_security_t;

/** Security Info Flags. */
enum bt_security_flag {
	/** Paired with Secure Connections. */
	BT_SECURITY_FLAG_SC = BIT(0),
	/** Paired with Out of Band method. */
	BT_SECURITY_FLAG_OOB = BIT(1),
};

/** Security Info Structure. */
struct bt_security_info {
	/** Security Level. */
	bt_security_t level;
	/** Encryption Key Size. */
	uint8_t enc_key_size;
	/** Flags. */
	enum bt_security_flag flags;
};

/** Connection Info Structure */
struct bt_conn_info {
	/** Connection Type. */
	enum bt_conn_type type;
	/** Connection Role. */
	uint8_t role;
	/** Which local identity the connection was created with */
	uint8_t id;
	/** Connection Type specific Info.*/
	union {
		/** LE Connection specific Info. */
		struct bt_conn_le_info le;
		/** BR/EDR Connection specific Info. */
		struct bt_conn_br_info br;
		/** SCO Connection specific Info. */
		struct bt_conn_sco_info sco;
	};
	/** Connection state. */
	enum bt_conn_state state;
	/** Security specific info. */
	struct bt_security_info security;
};

/** LE Connection Remote Info Structure */
struct bt_conn_le_remote_info {

	/** Remote LE feature set (bitmask). */
	const uint8_t *features;
};

/** BR/EDR Connection Remote Info structure */
struct bt_conn_br_remote_info {

	/** Remote feature set (pages of bitmasks). */
	const uint8_t *features;

	/** Number of pages in the remote feature set. */
	uint8_t num_pages;
};

/** @brief Connection Remote Info Structure
 *
 *  @note The version, manufacturer and subversion fields will only contain
 *        valid data if @kconfig{CONFIG_BT_REMOTE_VERSION} is enabled.
 */
struct bt_conn_remote_info {
	/** Connection Type */
	uint8_t  type;

	/** Remote Link Layer version */
	uint8_t  version;

	/** Remote manufacturer identifier */
	uint16_t manufacturer;

	/** Per-manufacturer unique revision */
	uint16_t subversion;

	union {
		/** LE connection remote info */
		struct bt_conn_le_remote_info le;

		/** BR/EDR connection remote info */
		struct bt_conn_br_remote_info br;
	};
};

enum bt_conn_le_tx_power_phy {
	/** Convenience macro for when no PHY is set. */
	BT_CONN_LE_TX_POWER_PHY_NONE,
	/** LE 1M PHY */
	BT_CONN_LE_TX_POWER_PHY_1M,
	 /** LE 2M PHY */
	BT_CONN_LE_TX_POWER_PHY_2M,
	/** LE Coded PHY using S=8 coding. */
	BT_CONN_LE_TX_POWER_PHY_CODED_S8,
	/** LE Coded PHY using S=2 coding. */
	BT_CONN_LE_TX_POWER_PHY_CODED_S2,
};

/** LE Transmit Power Level Structure */
struct bt_conn_le_tx_power {

	/** Input: 1M, 2M, Coded S2 or Coded S8 */
	uint8_t phy;

	/** Output: current transmit power level */
	int8_t current_level;

	/** Output: maximum transmit power level */
	int8_t max_level;
};


/** LE Transmit Power Reporting Structure */
struct bt_conn_le_tx_power_report {

	/** Reason for Transmit power reporting,
	 * as documented in Core Spec. Version 5.4 Vol. 4, Part E, 7.7.65.33.
	 */
	uint8_t reason;

	/** Phy of Transmit power reporting. */
	enum bt_conn_le_tx_power_phy phy;

	/** Transmit power level
	 * - 0xXX - Transmit power level
	 *  + Range: -127 to 20
	 *  + Units: dBm
	 *
	 * - 0x7E - Remote device is not managing power levels on this PHY.
	 * - 0x7F - Transmit power level is not available
	 */
	int8_t tx_power_level;

	/** Bit 0: Transmit power level is at minimum level.
	 *  Bit 1: Transmit power level is at maximum level.
	 */
	uint8_t tx_power_level_flag;

	/** Change in transmit power level
	 * - 0xXX - Change in transmit power level (positive indicates increased
	 *   power, negative indicates decreased power, zero indicates unchanged)
	 *   Units: dB
	 * - 0x7F - Change is not available or is out of range.
	 */
	int8_t delta;
};

/** @brief Path Loss zone that has been entered.
 *
 *  The path loss zone that has been entered in the most recent LE Path Loss Monitoring
 *  Threshold Change event as documented in Core Spec. Version 5.4 Vol.4, Part E, 7.7.65.32.
 *
 *  @note BT_CONN_LE_PATH_LOSS_ZONE_UNAVAILABLE has been added to notify when path loss becomes
 *        unavailable.
 */
enum bt_conn_le_path_loss_zone {
	/** Low path loss zone entered. */
	BT_CONN_LE_PATH_LOSS_ZONE_ENTERED_LOW,
	/** Middle path loss zone entered. */
	BT_CONN_LE_PATH_LOSS_ZONE_ENTERED_MIDDLE,
	/** High path loss zone entered. */
	BT_CONN_LE_PATH_LOSS_ZONE_ENTERED_HIGH,
	/** Path loss has become unavailable. */
	BT_CONN_LE_PATH_LOSS_ZONE_UNAVAILABLE,
};

BUILD_ASSERT(BT_CONN_LE_PATH_LOSS_ZONE_ENTERED_LOW == BT_HCI_LE_ZONE_ENTERED_LOW);
BUILD_ASSERT(BT_CONN_LE_PATH_LOSS_ZONE_ENTERED_MIDDLE == BT_HCI_LE_ZONE_ENTERED_MIDDLE);
BUILD_ASSERT(BT_CONN_LE_PATH_LOSS_ZONE_ENTERED_HIGH == BT_HCI_LE_ZONE_ENTERED_HIGH);

/** @brief LE Path Loss Monitoring Threshold Change Report Structure. */
struct bt_conn_le_path_loss_threshold_report {

	/** Path Loss zone as documented in Core Spec. Version 5.4 Vol.4, Part E, 7.7.65.32. */
	enum bt_conn_le_path_loss_zone zone;

	/** Current path loss (dB). */
	uint8_t path_loss;
};

/** @brief LE Path Loss Monitoring Parameters Structure as defined in Core Spec. Version 5.4
 *         Vol.4, Part E, 7.8.119 LE Set Path Loss Reporting Parameters command.
 */
struct bt_conn_le_path_loss_reporting_param {
	/** High threshold for the path loss (dB). */
	uint8_t high_threshold;
	/** Hysteresis value for the high threshold (dB). */
	uint8_t high_hysteresis;
	/** Low threshold for the path loss (dB). */
	uint8_t low_threshold;
	/** Hysteresis value for the low threshold (dB). */
	uint8_t low_hysteresis;
	/** Minimum time in number of connection events to be observed once the
	 *  path loss crosses the threshold before an event is generated.
	 */
	uint16_t min_time_spent;
};

/** @brief Passkey Keypress Notification type
 *
 *  The numeric values are the same as in the Core specification for Pairing
 *  Keypress Notification PDU.
 */
enum bt_conn_auth_keypress {
	BT_CONN_AUTH_KEYPRESS_ENTRY_STARTED = 0x00,
	BT_CONN_AUTH_KEYPRESS_DIGIT_ENTERED = 0x01,
	BT_CONN_AUTH_KEYPRESS_DIGIT_ERASED = 0x02,
	BT_CONN_AUTH_KEYPRESS_CLEARED = 0x03,
	BT_CONN_AUTH_KEYPRESS_ENTRY_COMPLETED = 0x04,
};

/** @brief Get connection info
 *
 *  @param conn Connection object.
 *  @param info Connection info object.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_get_info(const struct bt_conn *conn, struct bt_conn_info *info);

/** @brief Function to determine the type of a connection
 *
 *  @param conn The connection object
 *  @param type The types to check against. It is possible to supply multiple types,
 *              e.g. BT_CONN_TYPE_LE | BT_CONN_TYPE_SCO.
 *
 *  @retval true @p conn is of type @p type
 *  @retval false @p conn is either NULL or not of type @p type
 */
bool bt_conn_is_type(const struct bt_conn *conn, enum bt_conn_type type);

/** @brief Get connection info for the remote device.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *  @param remote_info Connection remote info object.
 *
 *  @note In order to retrieve the remote version (version, manufacturer
 *  and subversion) @kconfig{CONFIG_BT_REMOTE_VERSION} must be enabled
 *
 *  @note The remote information is exchanged directly after the connection has
 *  been established. The application can be notified about when the remote
 *  information is available through the remote_info_available callback.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EBUSY The remote information is not yet available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection.
 */
int bt_conn_get_remote_info(const struct bt_conn *conn, struct bt_conn_remote_info *remote_info);

/** @brief Get connection transmit power level.
 *
 *  @param conn           @ref BT_CONN_TYPE_LE connection object.
 *  @param tx_power_level Transmit power level descriptor.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -ENOBUFS HCI command buffer is not available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_get_tx_power_level(struct bt_conn *conn,
				  struct bt_conn_le_tx_power *tx_power_level);

/** @brief Get local enhanced connection transmit power level.
 *
 *  @param conn           @ref BT_CONN_TYPE_LE connection object.
 *  @param tx_power       Transmit power level descriptor.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @retval -ENOBUFS HCI command buffer is not available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_enhanced_get_tx_power_level(struct bt_conn *conn,
					   struct bt_conn_le_tx_power *tx_power);

/** @brief Get remote (peer) transmit power level.
 *
 *  @param conn           @ref BT_CONN_TYPE_LE connection object.
 *  @param phy            PHY information.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @retval -ENOBUFS HCI command buffer is not available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_get_remote_tx_power_level(struct bt_conn *conn,
					 enum bt_conn_le_tx_power_phy phy);

/** @brief Enable transmit power reporting.
 *
 *  @param conn           @ref BT_CONN_TYPE_LE connection object.
 *  @param local_enable   Enable/disable reporting for local.
 *  @param remote_enable  Enable/disable reporting for remote.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @retval -ENOBUFS HCI command buffer is not available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_set_tx_power_report_enable(struct bt_conn *conn,
					  bool local_enable,
					  bool remote_enable);

/** @brief Set Path Loss Monitoring Parameters.
 *
 *  Change the configuration for path loss threshold change events for a given conn handle.
 *
 *  @note To use this API @kconfig{CONFIG_BT_PATH_LOSS_MONITORING} must be set.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param param Path Loss Monitoring parameters
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_set_path_loss_mon_param(struct bt_conn *conn,
				       const struct bt_conn_le_path_loss_reporting_param *param);

/** @brief Enable or Disable Path Loss Monitoring.
 *
 * Enable or disable Path Loss Monitoring, which will decide whether Path Loss Threshold events
 * are sent from the controller to the host.
 *
 * @note To use this API @kconfig{CONFIG_BT_PATH_LOSS_MONITORING} must be set.
 *
 * @param conn  @ref BT_CONN_TYPE_LE connection object.
 * @param enable Enable/disable path loss reporting.
 *
 * @return Zero on success or (negative) error code on failure.
 * @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_set_path_loss_mon_enable(struct bt_conn *conn, bool enable);

/** @brief Set Default Connection Subrating Parameters.
 *
 *  Change the default subrating parameters for all future
 *  ACL connections where the local device is the central.
 *  This command does not affect any existing connection.
 *  Parameters set for specific connection will always have precedence.
 *
 *  @note To use this API @kconfig{CONFIG_BT_SUBRATING} and
 *        @kconfig{CONFIG_BT_CENTRAL} must be set.
 *
 *  @param params Subrating parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_subrate_set_defaults(const struct bt_conn_le_subrate_param *params);

/** @brief Request New Subrating Parameters.
 *
 *  Request a change to the subrating parameters of a connection.
 *
 *  @note To use this API @kconfig{CONFIG_BT_SUBRATING} must be set.
 *
 *  @param conn   @ref BT_CONN_TYPE_LE connection object.
 *  @param params Subrating parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_subrate_request(struct bt_conn *conn,
			       const struct bt_conn_le_subrate_param *params);

/** @brief Read Minimum Supported Connection Interval Groups.
 *
 *  Read the minimum supported connection interval and supported interval
 *  groups from the local controller. This information describes what the
 *  local controller supports.
 *
 *  @sa bt_conn_le_read_min_conn_interval if only
 *      @ref bt_conn_le_min_conn_interval_info.min_supported_conn_interval_us
 *      is needed.
 *
 *  @kconfig_dep{CONFIG_BT_SHORTER_CONNECTION_INTERVALS}
 *
 *  @param info Pointer to structure to receive the minimum connection interval
 *              information.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_read_min_conn_interval_groups(struct bt_conn_le_min_conn_interval_info *info);

/** @brief Read Minimum Supported Connection Interval.
 *
 *  Read the minimum supported connection interval from the local controller.
 *
 *  @sa bt_conn_le_read_min_conn_interval_groups if groups are needed.
 *
 *  @kconfig_dep{CONFIG_BT_SHORTER_CONNECTION_INTERVALS}
 *
 *  @param min_interval_us Pointer to variable to receive the minimum connection interval
 *                         in microseconds.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_read_min_conn_interval(uint16_t *min_interval_us);

/** @brief Set Default Connection Rate Parameters.
 *
 *  Configure the range of Connection Rate values that this device will
 *  accept from a Peripheral initiating a Connection Rate Update procedure.
 *
 *  The configured bounds:
 *   - Apply only to connections established after this call.
 *   - Are overridden on a given connection by any
 *     @ref bt_conn_le_conn_rate_request on that connection.
 *
 *  @kconfig_dep{CONFIG_BT_SHORTER_CONNECTION_INTERVALS,CONFIG_BT_CENTRAL}
 *
 *  @param params Connection rate parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_conn_rate_set_defaults(const struct bt_conn_le_conn_rate_param *params);

/** @brief Request New Connection Rate Parameters.
 *
 *  Request a change to the connection parameters of a connection. This includes
 *  Subrate parameters. This allows changing the connection interval to below the
 *  Baseline ConnInterval Values (BCV) and with finer granularity, if supported.
 *
 *  Valid intervals of the local and peer controller should be known.
 *  See @ref bt_conn_le_read_min_conn_interval_groups
 *
 *  @kconfig_dep{CONFIG_BT_SHORTER_CONNECTION_INTERVALS}
 *
 *  @param conn   @ref BT_CONN_TYPE_LE connection object.
 *  @param params Connection rate parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_conn_rate_request(struct bt_conn *conn,
				 const struct bt_conn_le_conn_rate_param *params);

/** @brief Read remote feature pages.
 *
 *  Request remote feature pages, from 0 up to pages_requested or the number
 *  of pages supported by the peer. There is a maximum of 10 pages.
 *  This function will trigger the read_all_remote_feat_complete callback
 *  when the procedure is completed.
 *
 *  @kconfig_dep{CONFIG_BT_LE_EXTENDED_FEAT_SET}
 *
 *  @param conn @ref BT_CONN_TYPE_LE connection object.
 *  @param pages_requested Number of feature pages to be requested from peer.
 *                         There is a maximum of 10 pages.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_read_all_remote_features(struct bt_conn *conn, uint8_t pages_requested);

/** @brief Update frame space.
 *
 *  Request a change to the frame space parameters of a connection.
 *  This function will trigger the frame_space_updated callback when the
 *  procedure is completed.
 *
 *  @kconfig_dep{CONFIG_BT_FRAME_SPACE_UPDATE}.
 *
 *  @param conn   @ref BT_CONN_TYPE_LE connection object.
 *  @param params Frame Space Update parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_frame_space_update(struct bt_conn *conn,
				  const struct bt_conn_le_frame_space_update_param *params);

/** @brief Update the connection parameters.
 *
 *  If the local device is in the peripheral role then updating the connection
 *  parameters will be delayed. This delay can be configured by through the
 *  @kconfig{CONFIG_BT_CONN_PARAM_UPDATE_TIMEOUT} option.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param param Updated connection parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_param_update(struct bt_conn *conn,
			    const struct bt_le_conn_param *param);

/** @brief Update the connection transmit data length parameters.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param param Updated data length parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_data_len_update(struct bt_conn *conn,
			       const struct bt_conn_le_data_len_param *param);

/** @brief Update the connection PHY parameters.
 *
 *  Update the preferred transmit and receive PHYs of the connection.
 *  Use @ref BT_GAP_LE_PHY_NONE to indicate no preference.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param param Updated connection parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_conn_le_phy_update(struct bt_conn *conn,
			  const struct bt_conn_le_phy_param *param);

/** @brief Update the default PHY parameters to be used for all subsequent
 * connections over the LE transport.
 *
 *  Update the preferred transmit and receive PHYs of LE transport.
 *  Use @ref BT_GAP_LE_PHY_NONE to indicate no preference.
 *  For possible PHY values see @ref bt_gap_le_phy.
 *
 *  @param pref_tx_phy  Preferred transmitter phy prarameters.
 *  @param pref_rx_phy  Preferred receiver phy prameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_set_default_phy(uint8_t pref_tx_phy, uint8_t pref_rx_phy);

/** @brief Disconnect from a remote device or cancel pending connection.
 *
 *  Disconnect an active connection with the specified reason code or cancel
 *  pending outgoing connection.
 *
 *  The disconnect reason for a normal disconnect should be:
 *  @ref BT_HCI_ERR_REMOTE_USER_TERM_CONN.
 *
 *  The following disconnect reasons are accepted:
 *   - @ref BT_HCI_ERR_AUTH_FAIL
 *   - @ref BT_HCI_ERR_REMOTE_USER_TERM_CONN
 *   - @ref BT_HCI_ERR_REMOTE_LOW_RESOURCES
 *   - @ref BT_HCI_ERR_REMOTE_POWER_OFF
 *   - @ref BT_HCI_ERR_UNSUPP_REMOTE_FEATURE
 *   - @ref BT_HCI_ERR_PAIRING_NOT_SUPPORTED
 *   - @ref BT_HCI_ERR_UNACCEPT_CONN_PARAM
 *
 *  @param conn Connection to disconnect.
 *  @param reason Reason code for the disconnection.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_disconnect(struct bt_conn *conn, uint8_t reason);

enum {
	/** Convenience value when no options are specified. */
	BT_CONN_LE_OPT_NONE = 0,

	/** @brief Enable LE Coded PHY.
	 *
	 *  Enable scanning on the LE Coded PHY.
	 */
	BT_CONN_LE_OPT_CODED = BIT(0),

	/** @brief Disable LE 1M PHY.
	 *
	 *  Disable scanning on the LE 1M PHY.
	 *
	 *  @note Requires @ref BT_CONN_LE_OPT_CODED.
	 */
	BT_CONN_LE_OPT_NO_1M = BIT(1),
};

struct bt_conn_le_create_param {

	/** Bit-field of create connection options. */
	uint32_t options;

	/** Scan interval (N * 0.625 ms)
	 *
	 * @note When @kconfig{CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL} is enabled
	 *       and the application wants to scan and connect in parallel,
	 *       the Bluetooth Controller may require the scan interval used
	 *       for scanning and connection establishment to be equal to
	 *       obtain the best performance.
	 */
	uint16_t interval;

	/** Scan window (N * 0.625 ms)
	 *
	 * @note When @kconfig{CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL} is enabled
	 *       and the application wants to scan and connect in parallel,
	 *       the Bluetooth Controller may require the scan window used
	 *       for scanning and connection establishment to be equal to
	 *       obtain the best performance.
	 */
	uint16_t window;

	/** @brief Scan interval LE Coded PHY (N * 0.625 MS)
	 *
	 *  Set zero to use same as LE 1M PHY scan interval
	 */
	uint16_t interval_coded;

	/** @brief Scan window LE Coded PHY (N * 0.625 MS)
	 *
	 *  Set zero to use same as LE 1M PHY scan window.
	 */
	uint16_t window_coded;

	/** @brief Connection initiation timeout (N * 10 MS)
	 *
	 *  Set zero to use the default @kconfig{CONFIG_BT_CREATE_CONN_TIMEOUT}
	 *  timeout.
	 *
	 *  @note Unused in @ref bt_conn_le_create_auto
	 */
	uint16_t timeout;
};

/** @brief Initialize create connection parameters
 *
 *  @param _options  Create connection options.
 *  @param _interval Create connection scan interval (N * 0.625 ms).
 *  @param _window   Create connection scan window (N * 0.625 ms).
 */
#define BT_CONN_LE_CREATE_PARAM_INIT(_options, _interval, _window) \
{ \
	.options = (_options), \
	.interval = (_interval), \
	.window = (_window), \
	.interval_coded = 0, \
	.window_coded = 0, \
	.timeout = 0, \
}

/** Helper to declare create connection parameters inline
 *
 *  @param _options  Create connection options.
 *  @param _interval Create connection scan interval (N * 0.625 ms).
 *  @param _window   Create connection scan window (N * 0.625 ms).
 */
#define BT_CONN_LE_CREATE_PARAM(_options, _interval, _window) \
	((struct bt_conn_le_create_param[]) { \
		BT_CONN_LE_CREATE_PARAM_INIT(_options, _interval, _window) \
	 })

/** Default LE create connection parameters.
 *  Scan continuously by setting scan interval equal to scan window.
 */
#define BT_CONN_LE_CREATE_CONN \
	BT_CONN_LE_CREATE_PARAM(BT_CONN_LE_OPT_NONE, \
				BT_GAP_SCAN_FAST_INTERVAL, \
				BT_GAP_SCAN_FAST_INTERVAL)

/** Default LE create connection using filter accept list parameters.
 *  Scan window:   30 ms.
 *  Scan interval: 60 ms.
 */
#define BT_CONN_LE_CREATE_CONN_AUTO \
	BT_CONN_LE_CREATE_PARAM(BT_CONN_LE_OPT_NONE, \
				BT_GAP_SCAN_FAST_INTERVAL, \
				BT_GAP_SCAN_FAST_WINDOW)

/** @brief Initiate an LE connection to a remote device.
 *
 *  Allows initiate new LE link to remote peer using its address.
 *
 *  The caller gets a new reference to the connection object which must be
 *  released with bt_conn_unref() once done using the object. If
 *  @kconfig{CONFIG_BT_CONN_CHECK_NULL_BEFORE_CREATE} is enabled, this function
 *  will return -EINVAL if dereferenced @p conn is not NULL.
 *
 *  This uses the General Connection Establishment procedure.
 *
 *  The application must disable explicit scanning before initiating
 *  a new LE connection if @kconfig{CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL}
 *  is not enabled.
 *
 *  @param[in]  peer         Remote address.
 *  @param[in]  create_param Create connection parameters.
 *  @param[in]  conn_param   Initial connection parameters.
 *  @param[out] conn         Valid connection object on success.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_create(const bt_addr_le_t *peer,
		      const struct bt_conn_le_create_param *create_param,
		      const struct bt_le_conn_param *conn_param,
		      struct bt_conn **conn);

struct bt_conn_le_create_synced_param {

	/** @brief Remote address
	 *
	 * The peer must be synchronized to the PAwR train.
	 *
	 */
	const bt_addr_le_t *peer;

	/** The subevent where the connection will be initiated. */
	uint8_t subevent;
};

/** @brief Create a connection to a synced device
 *
 *  Initiate a connection to a synced device from a Periodic Advertising
 *  with Responses (PAwR) train.
 *
 *  The caller gets a new reference to the connection object which must be
 *  released with bt_conn_unref() once done using the object. If
 *  @kconfig{CONFIG_BT_CONN_CHECK_NULL_BEFORE_CREATE} is enabled, this function
 *  will return -EINVAL if dereferenced @p conn is not NULL.
 *
 *  This uses the Periodic Advertising Connection Procedure.
 *
 *  @param[in]  adv          The adverting set the PAwR advertiser belongs to.
 *  @param[in]  synced_param Create connection parameters.
 *  @param[in]  conn_param   Initial connection parameters.
 *  @param[out] conn         Valid connection object on success.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_le_create_synced(const struct bt_le_ext_adv *adv,
			     const struct bt_conn_le_create_synced_param *synced_param,
			     const struct bt_le_conn_param *conn_param, struct bt_conn **conn);

/** @brief Automatically connect to remote devices in the filter accept list.
 *
 *  This uses the Auto Connection Establishment procedure.
 *  The procedure will continue until a single connection is established or the
 *  procedure is stopped through @ref bt_conn_create_auto_stop.
 *  To establish connections to all devices in the filter accept list the
 *  procedure should be started again in the connected callback after a
 *  new connection has been established.
 *
 *  @param create_param Create connection parameters
 *  @param conn_param   Initial connection parameters.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -ENOMEM No free connection object available.
 */
int bt_conn_le_create_auto(const struct bt_conn_le_create_param *create_param,
			   const struct bt_le_conn_param *conn_param);

/** @brief Stop automatic connect creation.
 *
 *  @return Zero on success or (negative) error code on failure.
 */
int bt_conn_create_auto_stop(void);

/** @brief Set security level for a connection.
 *
 *  This function enable security (encryption) for a connection. If the device
 *  has bond information for the peer with sufficiently strong key encryption
 *  will be enabled. If the connection is already encrypted with sufficiently
 *  strong key this function does nothing.
 *
 *  If the device has no bond information for the peer and is not already paired
 *  then the pairing procedure will be initiated. Note that @p sec has no effect
 *  on the security level selected for the pairing process. The selection is
 *  instead controlled by the values of the registered @ref bt_conn_auth_cb. If
 *  the device has bond information or is already paired and the keys are too
 *  weak then the pairing procedure will be initiated.
 *
 *  This function may return an error if the required level of security defined using
 *  @p sec is not possible to achieve due to local or remote device limitation
 *  (e.g., input output capabilities), or if the maximum number of paired devices
 *  has been reached.
 *
 *  This function may return an error if the pairing procedure has already been
 *  initiated by the local device or the peer device.
 *
 *  @note When @kconfig{CONFIG_BT_SMP_SC_ONLY} is enabled then the security
 *        level will always be level 4.
 *
 *  @note When @kconfig{CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY} is enabled then the
 *        security level will always be level 3.
 *
 *  @note When @ref BT_SECURITY_FORCE_PAIR within @p sec is enabled then the pairing
 *        procedure will always be initiated.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *  @param sec Requested minimum security level.
 *
 *  @return 0 on success or negative error
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection.
 */
int bt_conn_set_security(struct bt_conn *conn, bt_security_t sec);

/** @brief Get security level for a connection.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *
 *  @return Connection security level if @kconfig{CONFIG_BT_SMP} or @kconfig{CONFIG_BT_CLASSIC} is
 *          enabled, else @ref BT_SECURITY_L1
 *  @return @ref BT_SECURITY_L0 @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR
 *          connection.
 */
bt_security_t bt_conn_get_security(const struct bt_conn *conn);

/** @brief Get encryption key size.
 *
 *  This function gets encryption key size.
 *  If there is no security (encryption) enabled 0 will be returned.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *
 *  @return Encryption key size.
 *  @return 0 @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection.
 */
uint8_t bt_conn_enc_key_size(const struct bt_conn *conn);

enum bt_security_err {
	/** Security procedure successful. */
	BT_SECURITY_ERR_SUCCESS,

	/** Authentication failed. */
	BT_SECURITY_ERR_AUTH_FAIL,

	/** PIN or encryption key is missing. */
	BT_SECURITY_ERR_PIN_OR_KEY_MISSING,

	/** OOB data is not available.  */
	BT_SECURITY_ERR_OOB_NOT_AVAILABLE,

	/** The requested security level could not be reached. */
	BT_SECURITY_ERR_AUTH_REQUIREMENT,

	/** Pairing is not supported */
	BT_SECURITY_ERR_PAIR_NOT_SUPPORTED,

	/** Pairing is not allowed. */
	BT_SECURITY_ERR_PAIR_NOT_ALLOWED,

	/** Invalid parameters. */
	BT_SECURITY_ERR_INVALID_PARAM,

	/** Distributed Key Rejected */
	BT_SECURITY_ERR_KEY_REJECTED,

	/** Pairing failed but the exact reason could not be specified. */
	BT_SECURITY_ERR_UNSPECIFIED,
};

enum bt_conn_le_cs_procedure_enable_state {
	BT_CONN_LE_CS_PROCEDURES_DISABLED = BT_HCI_OP_LE_CS_PROCEDURES_DISABLED,
	BT_CONN_LE_CS_PROCEDURES_ENABLED = BT_HCI_OP_LE_CS_PROCEDURES_ENABLED,
};

/** CS Test Tone Antenna Config Selection.
 *
 *  These enum values are indices in the following table, where N_AP is the maximum
 *  number of antenna paths (in the range [1, 4]).
 *
 * +--------------+-------------+-------------------+-------------------+--------+
 * | Config Index | Total Paths | Dev A: # Antennas | Dev B: # Antennas | Config |
 * +--------------+-------------+-------------------+-------------------+--------+
 * |            0 |           1 |                 1 |                 1 | 1:1    |
 * |            1 |           2 |                 2 |                 1 | N_AP:1 |
 * |            2 |           3 |                 3 |                 1 | N_AP:1 |
 * |            3 |           4 |                 4 |                 1 | N_AP:1 |
 * |            4 |           2 |                 1 |                 2 | 1:N_AP |
 * |            5 |           3 |                 1 |                 3 | 1:N_AP |
 * |            6 |           4 |                 1 |                 4 | 1:N_AP |
 * |            7 |           4 |                 2 |                 2 | 2:2    |
 * +--------------+-------------+-------------------+-------------------+--------+
 *
 *  There are therefore four groups of possible antenna configurations:
 *
 *  - 1:1 configuration, where both A and B support 1 antenna each
 *  - 1:N_AP configuration, where A supports 1 antenna, B supports N_AP antennas, and
 *    N_AP is a value in the range [2, 4]
 *  - N_AP:1 configuration, where A supports N_AP antennas, B supports 1 antenna, and
 *    N_AP is a value in the range [2, 4]
 *  - 2:2 configuration, where both A and B support 2 antennas and N_AP = 4
 */
enum bt_conn_le_cs_tone_antenna_config_selection {
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A1_B1 = BT_HCI_OP_LE_CS_ACI_0,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A2_B1 = BT_HCI_OP_LE_CS_ACI_1,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A3_B1 = BT_HCI_OP_LE_CS_ACI_2,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A4_B1 = BT_HCI_OP_LE_CS_ACI_3,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A1_B2 = BT_HCI_OP_LE_CS_ACI_4,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A1_B3 = BT_HCI_OP_LE_CS_ACI_5,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A1_B4 = BT_HCI_OP_LE_CS_ACI_6,
	BT_LE_CS_TONE_ANTENNA_CONFIGURATION_A2_B2 = BT_HCI_OP_LE_CS_ACI_7,
};

struct bt_conn_le_cs_procedure_enable_complete {
	/* The ID associated with the desired configuration (0 to 3) */
	uint8_t config_id;

	/* State of the CS procedure */
	enum bt_conn_le_cs_procedure_enable_state state;

	/* Antenna configuration index */
	enum bt_conn_le_cs_tone_antenna_config_selection tone_antenna_config_selection;

	/* Transmit power level used for CS procedures (-127 to 20 dB; 0x7F if unavailable) */
	int8_t selected_tx_power;

	/* Duration of each CS subevent in microseconds (1250 us to 4 s) */
	uint32_t subevent_len;

	/* Number of CS subevents anchored off the same ACL connection event (0x01 to 0x20) */
	uint8_t subevents_per_event;

	/* Time between consecutive CS subevents anchored off the same ACL connection event in
	 * units of 0.625 ms
	 */
	uint16_t subevent_interval;

	/* Number of ACL connection events between consecutive CS event anchor points */
	uint16_t event_interval;

	/* Number of ACL connection events between consecutive CS procedure anchor points */
	uint16_t procedure_interval;

	/* Number of CS procedures to be scheduled (0 if procedures to continue until disabled) */
	uint16_t procedure_count;

	/* Maximum duration for each procedure in units of 0.625 ms (0x0001 to 0xFFFF) */
	uint16_t max_procedure_len;
};

/** @brief Connection callback structure.
 *
 *  This structure is used for tracking the state of a connection.
 *  It is registered with the help of the bt_conn_cb_register() API.
 *  It's permissible to register multiple instances of this @ref bt_conn_cb
 *  type, in case different modules of an application are interested in
 *  tracking the connection state. If a callback is not of interest for
 *  an instance, it may be set to NULL and will as a consequence not be
 *  used for that instance.
 */
struct bt_conn_cb {
	/** @brief A new connection has been established.
	 *
	 *  This callback notifies the application of a new connection.
	 *  In case the err parameter is non-zero it means that the
	 *  connection establishment failed.
	 *
	 *  @note If the connection was established from an advertising set then
	 *        the advertising set cannot be restarted directly from this
	 *        callback. Instead use the connected callback of the
	 *        advertising set.
	 *
	 *  @param conn New connection object.
	 *  @param err HCI error. Zero for success, non-zero otherwise.
	 *
	 *  @p err can mean either of the following:
	 *  - @ref BT_HCI_ERR_UNKNOWN_CONN_ID Creating the connection started by
	 *    @ref bt_conn_le_create was canceled either by the user through
	 *    @ref bt_conn_disconnect or by the timeout in the host through
	 *    @ref bt_conn_le_create_param timeout parameter, which defaults to
	 *    @kconfig{CONFIG_BT_CREATE_CONN_TIMEOUT} seconds.
	 *  - @p BT_HCI_ERR_ADV_TIMEOUT High duty cycle directed connectable
	 *    advertiser started by @ref bt_le_adv_start failed to be connected
	 *    within the timeout.
	 */
	void (*connected)(struct bt_conn *conn, uint8_t err);

	/** @brief A connection has been disconnected.
	 *
	 *  This callback notifies the application that a connection
	 *  has been disconnected.
	 *
	 *  When this callback is called the stack still has one reference to
	 *  the connection object. If the application in this callback tries to
	 *  start either a connectable advertiser or create a new connection
	 *  this might fail because there are no free connection objects
	 *  available.
	 *  To avoid this issue, it's recommended to rely instead on @ref bt_conn_cb.recycled
	 *  which notifies the application when a connection object has actually been freed.
	 *
	 *  @param conn Connection object.
	 *  @param reason BT_HCI_ERR_* reason for the disconnection.
	 */
	void (*disconnected)(struct bt_conn *conn, uint8_t reason);

	/** @brief A connection object has been returned to the pool.
	 *
	 * This callback notifies the application that it might be able to
	 * allocate a connection object. No guarantee, first come, first serve.
	 * Only connections that are configurable by @kconfig{CONFIG_BT_MAX_CONN} trigger this
	 * callback, i.e. connections of type @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR.
	 *
	 * The maximum number of simultaneous connections is configured
	 * by @kconfig{CONFIG_BT_MAX_CONN}.
	 *
	 * This is the event to listen for to start a new connection or connectable advertiser,
	 * both when the intention is to start it after the system is completely
	 * finished with an earlier connection, and when the application wants to start
	 * a connection for any reason but failed and is waiting for the right time to retry.
	 */
	void (*recycled)(void);

	/** @brief LE connection parameter update request.
	 *
	 *  This callback notifies the application that a remote device
	 *  is requesting to update the connection parameters. The
	 *  application accepts the parameters by returning true, or
	 *  rejects them by returning false. Before accepting, the
	 *  application may also adjust the parameters to better suit
	 *  its needs.
	 *
	 *  It is recommended for an application to have just one of these
	 *  callbacks for simplicity. However, if an application registers
	 *  multiple it needs to manage the potentially different
	 *  requirements for each callback. Each callback gets the
	 *  parameters as returned by previous callbacks, i.e. they are not
	 *  necessarily the same ones as the remote originally sent.
	 *
	 *  If the application does not have this callback then the default
	 *  is to accept the parameters.
	 *
	 *  @param conn Connection object.
	 *  @param param Proposed connection parameters.
	 *
	 *  @return true to accept the parameters, or false to reject them.
	 */
	bool (*le_param_req)(struct bt_conn *conn,
			     struct bt_le_conn_param *param);

	/** @brief The parameters for an LE connection have been updated.
	 *
	 *  This callback notifies the application that the connection
	 *  parameters for an LE connection have been updated.
	 *
	 *  @param conn Connection object.
	 *  @param interval Connection interval.
	 *  @param latency Connection latency.
	 *  @param timeout Connection supervision timeout.
	 */
	void (*le_param_updated)(struct bt_conn *conn, uint16_t interval,
				 uint16_t latency, uint16_t timeout);
#if defined(CONFIG_BT_SMP)
	/** @brief Remote Identity Address has been resolved.
	 *
	 *  This callback notifies the application that a remote
	 *  Identity Address has been resolved
	 *
	 *  @param conn Connection object.
	 *  @param rpa Resolvable Private Address.
	 *  @param identity Identity Address.
	 */
	void (*identity_resolved)(struct bt_conn *conn,
				  const bt_addr_le_t *rpa,
				  const bt_addr_le_t *identity);
#endif /* CONFIG_BT_SMP */
#if defined(CONFIG_BT_SMP) || defined(CONFIG_BT_CLASSIC)
	/** @brief The security level of a connection has changed.
	 *
	 *  This callback notifies the application that the security of a
	 *  connection has changed.
	 *
	 *  The security level of the connection can either have been increased
	 *  or remain unchanged. An increased security level means that the
	 *  pairing procedure has been performed or the bond information from
	 *  a previous connection has been applied. If the security level
	 *  remains unchanged this means that the encryption key has been
	 *  refreshed for the connection.
	 *
	 *  @param conn Connection object.
	 *  @param level New security level of the connection.
	 *  @param err Security error. Zero for success, non-zero otherwise.
	 */
	void (*security_changed)(struct bt_conn *conn, bt_security_t level,
				 enum bt_security_err err);
#endif /* defined(CONFIG_BT_SMP) || defined(CONFIG_BT_CLASSIC) */

#if defined(CONFIG_BT_REMOTE_INFO)
	/** @brief Remote information procedures has completed.
	 *
	 *  This callback notifies the application that the remote information
	 *  has been retrieved from the remote peer.
	 *
	 *  @param conn Connection object.
	 *  @param remote_info Connection information of remote device.
	 */
	void (*remote_info_available)(struct bt_conn *conn,
				      struct bt_conn_remote_info *remote_info);
#endif /* defined(CONFIG_BT_REMOTE_INFO) */

#if defined(CONFIG_BT_POWER_MODE_CONTROL)
	/** @brief The connection mode change
	 *
	 *  This callback notifies the application that the sniff mode has changed
	 *
	 *  @param conn Connection object.
	 *  @param mode Active/Sniff mode.
	 *  @param interval Sniff interval.
	 */
	void (*br_mode_changed)(struct bt_conn *conn, uint8_t mode, uint16_t interval);
#endif /* CONFIG_BT_POWER_MODE_CONTROL */

#if defined(CONFIG_BT_USER_PHY_UPDATE)
	/** @brief The PHY of the connection has changed.
	 *
	 *  This callback notifies the application that the PHY of the
	 *  connection has changed.
	 *
	 *  @param conn Connection object.
	 *  @param info Connection LE PHY information.
	 */
	void (*le_phy_updated)(struct bt_conn *conn,
			       struct bt_conn_le_phy_info *param);
#endif /* defined(CONFIG_BT_USER_PHY_UPDATE) */

#if defined(CONFIG_BT_USER_DATA_LEN_UPDATE)
	/** @brief The data length parameters of the connection has changed.
	 *
	 *  This callback notifies the application that the maximum Link Layer
	 *  payload length or transmission time has changed.
	 *
	 *  @param conn Connection object.
	 *  @param info Connection data length information.
	 */
	void (*le_data_len_updated)(struct bt_conn *conn,
				    struct bt_conn_le_data_len_info *info);
#endif /* defined(CONFIG_BT_USER_DATA_LEN_UPDATE) */

#if defined(CONFIG_BT_DF_CONNECTION_CTE_RX)
	/** @brief Callback for IQ samples report collected when sampling
	 *        CTE received by data channel PDU.
	 *
	 * @param conn      The connection object.
	 * @param iq_report Report data for collected IQ samples.
	 */
	void (*cte_report_cb)(struct bt_conn *conn,
			      const struct bt_df_conn_iq_samples_report *iq_report);
#endif /* CONFIG_BT_DF_CONNECTION_CTE_RX */

#if defined(CONFIG_BT_TRANSMIT_POWER_CONTROL)
	/** @brief LE Read Remote Transmit Power Level procedure has completed or LE
	 *  Transmit Power Reporting event.
	 *
	 *  This callback notifies the application that either the remote transmit power level
	 *  has been read from the peer or transmit power level has changed for the local or
	 *  remote controller when transmit power reporting is enabled for the respective side
	 *  using @ref bt_conn_le_set_tx_power_report_enable.
	 *
	 *  @param conn Connection object.
	 *  @param report Transmit power report.
	 */
	void (*tx_power_report)(struct bt_conn *conn,
				const struct bt_conn_le_tx_power_report *report);
#endif /* CONFIG_BT_TRANSMIT_POWER_CONTROL */

#if defined(CONFIG_BT_PATH_LOSS_MONITORING)
	/** @brief LE Path Loss Threshold event.
	 *
	 *  This callback notifies the application that there has been a path loss threshold
	 *  crossing or reporting the initial path loss threshold zone after using
	 *  @ref bt_conn_le_set_path_loss_mon_enable.
	 *
	 *  @param conn Connection object.
	 *  @param report Path loss threshold report.
	 */
	void (*path_loss_threshold_report)(struct bt_conn *conn,
				const struct bt_conn_le_path_loss_threshold_report *report);
#endif /* CONFIG_BT_PATH_LOSS_MONITORING */

#if defined(CONFIG_BT_SUBRATING)
	/** @brief LE Subrate Changed event.
	 *
	 *  This callback notifies the application that the subrating parameters
	 *  of the connection may have changed.
	 *  The connection subrating parameters will be unchanged
	 *  if status is not BT_HCI_ERR_SUCCESS.
	 *
	 *  @param conn   Connection object.
	 *  @param params New subrating parameters.
	 */
	void (*subrate_changed)(struct bt_conn *conn,
				const struct bt_conn_le_subrate_changed *params);
#endif /* CONFIG_BT_SUBRATING */

#if defined(CONFIG_BT_SHORTER_CONNECTION_INTERVALS) || defined(__DOXYGEN__)
	/** @brief LE Connection Rate Changed event.
	 *
	 *  This callback notifies the application that the connection rate
	 *  parameters (including both connection interval and subrating)
	 *  of the connection may have changed.
	 *
	 *  @param conn   Connection object.
	 *  @param status HCI Status from LE Connection Rate Change event.
	 *                Possible Status codes:
	 *                - Success (0x00)
	 *                - Unknown Connection Identifier (0x02)
	 *                - Command Disallowed (0x0C)
	 *                - Unsupported Feature or Parameter Value (0x11)
	 *                - Invalid HCI Command Parameters (0x12)
	 *                - Unsupported Remote Feature (0x1A)
	 *                - Unsupported LL Parameter Value (0x20)
	 *  @param params New connection rate parameters.
	 *                The connection rate parameters will be NULL
	 *                if @p status is not @ref BT_HCI_ERR_SUCCESS.
	 */
	void (*conn_rate_changed)(struct bt_conn *conn, uint8_t status,
				  const struct bt_conn_le_conn_rate_changed *params);
#endif /* CONFIG_BT_SHORTER_CONNECTION_INTERVALS */

#if defined(CONFIG_BT_LE_EXTENDED_FEAT_SET)
	/** @brief Read all remote features complete event.
	 *
	 *  This callback notifies the application that a 'read all remote
	 *  features' procedure of the connection is completed. The other params
	 *  will not be populated if status is not @ref BT_HCI_ERR_SUCCESS.
	 *
	 *  This callback can be triggered by calling @ref
	 *  bt_conn_le_read_all_remote_features or by the procedure running
	 *  autonomously in the controller.
	 *
	 *  @param conn   Connection object.
	 *  @param params Remote features.
	 */
	void (*read_all_remote_feat_complete)(
		struct bt_conn *conn,
		const struct bt_conn_le_read_all_remote_feat_complete *params);
#endif /* CONFIG_BT_LE_EXTENDED_FEAT_SET */

#if defined(CONFIG_BT_FRAME_SPACE_UPDATE)
	/** @brief Frame Space Update Complete event.
	 *
	 *  This callback notifies the application that the frame space of
	 *  the connection may have changed.
	 *  The frame space update parameters will be invalid
	 *  if status is not @ref BT_HCI_ERR_SUCCESS.
	 *
	 *  This callback can be triggered by calling @ref
	 *  bt_conn_le_frame_space_update, by the procedure running
	 *  autonomously in the controller or by the peer.
	 *
	 *  @param conn   Connection object.
	 *  @param params New frame space update parameters.
	 */
	void (*frame_space_updated)(
		struct bt_conn *conn,
		const struct bt_conn_le_frame_space_updated *params);
#endif /* CONFIG_BT_FRAME_SPACE_UPDATE */

#if defined(CONFIG_BT_CHANNEL_SOUNDING)
	/** @brief LE CS Read Remote Supported Capabilities Complete event.
	 *
	 *  This callback notifies the application that a Channel Sounding
	 *  Capabilities Exchange procedure has completed.
	 *
	 *  If status is BT_HCI_ERR_SUCCESS, the remote channel
	 *  sounding capabilities have been received from the peer.
	 *
	 *  @param conn Connection object.
	 *  @param status HCI status of complete event.
	 *  @param remote_cs_capabilities Pointer to CS Capabilities on success or NULL otherwise.
	 */
	void (*le_cs_read_remote_capabilities_complete)(struct bt_conn *conn,
							uint8_t status,
							struct bt_conn_le_cs_capabilities *params);

	/** @brief LE CS Read Remote FAE Table Complete event.
	 *
	 *  This callback notifies the application that a Channel Sounding
	 *  Mode-0 FAE Table Request procedure has completed.
	 *
	 *  If status is BT_HCI_ERR_SUCCESS, the remote mode-0
	 *  FAE Table has been received from the peer.
	 *
	 *  @param conn Connection object.
	 *  @param status HCI status of complete event.
	 *  @param params Pointer to FAE Table on success or NULL otherwise.
	 */
	void (*le_cs_read_remote_fae_table_complete)(struct bt_conn *conn,
						     uint8_t status,
						     struct bt_conn_le_cs_fae_table *params);

	/** @brief LE CS Config created.
	 *
	 *  This callback notifies the application that a Channel Sounding
	 *  Configuration procedure has completed.
	 *
	 *  If status is BT_HCI_ERR_SUCCESS, a new CS config is created.
	 *
	 *  @param conn Connection object.
	 *  @param status HCI status of complete event.
	 *  @param config Pointer to CS configuration on success or NULL otherwise.
	 */
	void (*le_cs_config_complete)(struct bt_conn *conn,
				      uint8_t status,
				      struct bt_conn_le_cs_config *config);

	/** @brief LE CS Config removed.
	 *
	 *  This callback notifies the application that a Channel Sounding
	 *  Configuration procedure has completed and a CS config is removed
	 *
	 *  @param conn Connection object.
	 *  @param config_id ID of the CS configuration that was removed.
	 */
	void (*le_cs_config_removed)(struct bt_conn *conn, uint8_t config_id);

	/** @brief Subevent Results from a CS procedure are available.
	 *
	 * This callback notifies the user that CS subevent results are
	 * available for the given connection object.
	 *
	 * @param conn Connection objects.
	 * @param result Subevent results
	 */
	void (*le_cs_subevent_data_available)(struct bt_conn *conn,
					      struct bt_conn_le_cs_subevent_result *result);

	/** @brief LE CS Security Enabled.
	 *
	 *  This callback notifies the application that a Channel Sounding
	 *  Security Enable procedure has completed.
	 *
	 *  If status is BT_HCI_ERR_SUCCESS, CS Security is enabled.
	 *
	 *  @param conn Connection object.
	 *  @param status HCI status of complete event.
	 */
	void (*le_cs_security_enable_complete)(struct bt_conn *conn, uint8_t status);

	/** @brief LE CS Procedure Enabled.
	 *
	 *  This callback notifies the application that a Channel Sounding
	 *  Procedure Enable procedure has completed.
	 *
	 *  If status is BT_HCI_ERR_SUCCESS, CS procedure is enabled.
	 *
	 *  @param conn Connection object.
	 *  @param status HCI status.
	 *  @param params Pointer to CS Procedure Enable parameters on success or NULL otherwise.
	 */
	void (*le_cs_procedure_enable_complete)(
		struct bt_conn *conn, uint8_t status,
		struct bt_conn_le_cs_procedure_enable_complete *params);

#endif

#if defined(CONFIG_BT_CLASSIC)
	/** @brief The role of the connection has changed.
	 *
	 *  This callback notifies the application that the role switch procedure has completed.
	 *
	 *  @param conn Connection object.
	 *  @param status HCI status of role change event.
	 */
	void (*role_changed)(struct bt_conn *conn, uint8_t status);
#endif

#if defined(CONFIG_BT_CONN_DYNAMIC_CALLBACKS)
	/** @internal Internally used field for list handling */
	sys_snode_t _node;
#endif
};

/** @brief Register connection callbacks.
 *
 *  Register callbacks to monitor the state of connections.
 *
 *  @param cb Callback struct. Must point to memory that remains valid.
 *
 * @retval 0 Success.
 * @retval -EEXIST if @p cb was already registered.
 */
int bt_conn_cb_register(struct bt_conn_cb *cb);

/**
 * @brief Unregister connection callbacks.
 *
 * Unregister the state of connections callbacks.
 *
 * @param cb Callback struct point to memory that remains valid.
 *
 * @retval 0 Success
 * @retval -EINVAL If @p cb is NULL
 * @retval -ENOENT if @p cb was not registered
 */
int bt_conn_cb_unregister(struct bt_conn_cb *cb);

/**
 *  @brief Register a callback structure for connection events.
 *
 *  @param _name Name of callback structure.
 */
#define BT_CONN_CB_DEFINE(_name)					\
	static const STRUCT_SECTION_ITERABLE(bt_conn_cb,		\
						_CONCAT(bt_conn_cb_,	\
							_name))

/** Converts a security error to string.
 *
 * @return The string representation of the security error code.
 *         If @kconfig{CONFIG_BT_SECURITY_ERR_TO_STR} is not enabled,
 *         this just returns the empty string
 */
#if defined(CONFIG_BT_SECURITY_ERR_TO_STR)
const char *bt_security_err_to_str(enum bt_security_err err);
#else
static inline const char *bt_security_err_to_str(enum bt_security_err err)
{
	ARG_UNUSED(err);

	return "";
}
#endif

/** @brief Enable/disable bonding.
 *
 *  Set/clear the Bonding flag in the Authentication Requirements of
 *  SMP Pairing Request/Response data.
 *  The initial value of this flag depends on BT_BONDABLE Kconfig setting.
 *  For the vast majority of applications calling this function shouldn't be
 *  needed.
 *
 *  @param enable Value allowing/disallowing to be bondable.
 */
void bt_set_bondable(bool enable);

/** @brief Get bonding flag.
 *
 *  Get current bonding flag.
 *  The initial value of this flag depends on @kconfig{CONFIG_BT_BONDABLE} Kconfig
 *  setting.
 *  The Bonding flag can be updated using bt_set_bondable().
 *
 *  @return Current bonding flag.
 */
bool bt_get_bondable(void);

/** @brief Set/clear the bonding flag for a given connection.
 *
 *  Set/clear the Bonding flag in the Authentication Requirements of
 *  SMP Pairing Request/Response data for a given connection.
 *
 *  The bonding flag for a given connection cannot be set/cleared if
 *  security procedures in the SMP module have already started.
 *  This function can be called only once per connection.
 *
 *  If the bonding flag is not set/cleared for a given connection,
 *  the value will depend on global configuration which is set using
 *  bt_set_bondable.
 *  The default value of the global configuration is defined using
 *  CONFIG_BT_BONDABLE Kconfig option.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *  @param enable Value allowing/disallowing to be bondable.
 *
 *  @retval 0 Success
 *  @retval -EALREADY Already in the requested state
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection
 *  @return -EINVAL @p conn is a valid @ref BT_CONN_TYPE_LE but could not get SMP context
 */
int bt_conn_set_bondable(struct bt_conn *conn, bool enable);

/** @brief Allow/disallow remote LE SC OOB data to be used for pairing.
 *
 *  Set/clear the OOB data flag for LE SC SMP Pairing Request/Response data.
 *
 *  @param enable Value allowing/disallowing remote LE SC OOB data.
 */
void bt_le_oob_set_sc_flag(bool enable);

/** @brief Allow/disallow remote legacy OOB data to be used for pairing.
 *
 *  Set/clear the OOB data flag for legacy SMP Pairing Request/Response data.
 *
 *  @param enable Value allowing/disallowing remote legacy OOB data.
 */
void bt_le_oob_set_legacy_flag(bool enable);

/** @brief Set OOB Temporary Key to be used for pairing
 *
 *  This function allows to set OOB data for the LE legacy pairing procedure.
 *  The function should only be called in response to the oob_data_request()
 *  callback provided that the legacy method is user pairing.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param tk Pointer to 16 byte long TK array. The TK value should be generated randomly for each
 *            new pairing process.
 *
 *  @retval 0 Success
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 *  @return -EINVAL @p tk is NULL.
 */
int bt_le_oob_set_legacy_tk(struct bt_conn *conn, const uint8_t *tk);

/** @brief Set OOB data during LE Secure Connections (SC) pairing procedure
 *
 *  This function allows to set OOB data during the LE SC pairing procedure.
 *  The function should only be called in response to the oob_data_request()
 *  callback provided that LE SC method is used for pairing.
 *
 *  The user should submit OOB data according to the information received in the
 *  callback. This may yield three different configurations: with only local OOB
 *  data present, with only remote OOB data present or with both local and
 *  remote OOB data present.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param oobd_local Local OOB data or NULL if not present
 *  @param oobd_remote Remote OOB data or NULL if not present
 *
 *  @return Zero on success or error code otherwise, positive in case of
 *          protocol error or negative (POSIX) in case of stack internal error.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_le_oob_set_sc_data(struct bt_conn *conn,
			  const struct bt_le_oob_sc_data *oobd_local,
			  const struct bt_le_oob_sc_data *oobd_remote);

/** @brief Get OOB data used for LE Secure Connections (SC) pairing procedure
 *
 *  This function allows to get OOB data during the LE SC pairing procedure that
 *  were set by the bt_le_oob_set_sc_data() API.
 *
 *  @note The OOB data will only be available as long as the connection object
 *  associated with it is valid.
 *
 *  @param conn  @ref BT_CONN_TYPE_LE connection object.
 *  @param oobd_local Local OOB data or NULL if not set
 *  @param oobd_remote Remote OOB data or NULL if not set
 *
 *  @return Zero on success or error code otherwise, positive in case of
 *          protocol error or negative (POSIX) in case of stack internal error.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection.
 */
int bt_le_oob_get_sc_data(struct bt_conn *conn,
			  const struct bt_le_oob_sc_data **oobd_local,
			  const struct bt_le_oob_sc_data **oobd_remote);

/**
 *  DEPRECATED - use @ref BT_PASSKEY_RAND instead. Special passkey value that can be used to disable
 *  a previously set fixed passkey.
 */
#define BT_PASSKEY_INVALID 0xffffffff

/** @brief Set a fixed passkey to be used for pairing.
 *
 *  This API is only available when the CONFIG_BT_FIXED_PASSKEY
 *  configuration option has been enabled.
 *
 *  Sets a fixed passkey to be used for pairing. If set, the
 *  pairing_confirm() callback will be called for all incoming pairings.
 *
 * @deprecated Use @ref BT_PASSKEY_RAND and the app_passkey callback from @ref bt_conn_auth_cb
 *             instead.
 *
 *  @param passkey A valid passkey (0 - 999999) or BT_PASSKEY_INVALID
 *                 to disable a previously set fixed passkey.
 *
 *  @return 0 on success or a negative error code on failure.
 */
__deprecated int bt_passkey_set(unsigned int passkey);

/** Info Structure for OOB pairing */
struct bt_conn_oob_info {
	/** Type of OOB pairing method */
	enum {
		/** LE legacy pairing */
		BT_CONN_OOB_LE_LEGACY,

		/** LE SC pairing */
		BT_CONN_OOB_LE_SC,
	} type;

	union {
		/** LE Secure Connections OOB pairing parameters */
		struct {
			/** OOB data configuration */
			enum {
				/** Local OOB data requested */
				BT_CONN_OOB_LOCAL_ONLY,

				/** Remote OOB data requested */
				BT_CONN_OOB_REMOTE_ONLY,

				/** Both local and remote OOB data requested */
				BT_CONN_OOB_BOTH_PEERS,

				/** No OOB data requested */
				BT_CONN_OOB_NO_DATA,
			} oob_config;
		} lesc;
	};
};

#if defined(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)
/** @brief Pairing request and pairing response info structure.
 *
 *  This structure is the same for both smp_pairing_req and smp_pairing_rsp
 *  and a subset of the packet data, except for the initial Code octet.
 *  It is documented in Core Spec. Vol. 3, Part H, 3.5.1 and 3.5.2.
 */
struct bt_conn_pairing_feat {
	/** IO Capability, Core Spec. Vol 3, Part H, 3.5.1, Table 3.4 */
	uint8_t io_capability;

	/** OOB data flag, Core Spec. Vol 3, Part H, 3.5.1, Table 3.5 */
	uint8_t oob_data_flag;

	/** AuthReq, Core Spec. Vol 3, Part H, 3.5.1, Fig. 3.3 */
	uint8_t auth_req;

	/** Maximum Encryption Key Size, Core Spec. Vol 3, Part H, 3.5.1 */
	uint8_t max_enc_key_size;

	/** Initiator Key Distribution/Generation, Core Spec. Vol 3, Part H,
	 *  3.6.1, Fig. 3.11
	 */
	uint8_t init_key_dist;

	/** Responder Key Distribution/Generation, Core Spec. Vol 3, Part H
	 *  3.6.1, Fig. 3.11
	 */
	uint8_t resp_key_dist;
};
#endif /* CONFIG_BT_SMP_APP_PAIRING_ACCEPT */

/**
 * Special passkey value that can be used to generate a random passkey when using the
 * app_passkey callback from @ref bt_conn_auth_cb.
 *
 */
#define BT_PASSKEY_RAND 0xffffffff

/** Authenticated pairing callback structure */
struct bt_conn_auth_cb {
#if defined(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)
	/** @brief Query to proceed incoming pairing or not.
	 *
	 *  On any incoming pairing req/rsp this callback will be called for
	 *  the application to decide whether to allow for the pairing to
	 *  continue.
	 *
	 *  The pairing info received from the peer is passed to assist
	 *  making the decision.
	 *
	 *  As this callback is synchronous the application should return
	 *  a response value immediately. Otherwise it may affect the
	 *  timing during pairing. Hence, this information should not be
	 *  conveyed to the user to take action.
	 *
	 *  The remaining callbacks are not affected by this, but do notice
	 *  that other callbacks can be called during the pairing. Eg. if
	 *  pairing_confirm is registered both will be called for Just-Works
	 *  pairings.
	 *
	 *  This callback may be unregistered in which case pairing continues
	 *  as if the Kconfig flag was not set.
	 *
	 *  For BR/EDR Secure Simple Pairing (SSP), this callback is called
	 *  when receiving the BT_HCI_EVT_IO_CAPA_REQ hci event. The feat is
	 *  NULL here.
	 *
	 *  @param conn Connection where pairing is initiated.
	 *  @param feat Pairing req/resp info. It is NULL in BR/EDR SSP.
	 */
	enum bt_security_err (*pairing_accept)(struct bt_conn *conn,
			      const struct bt_conn_pairing_feat *const feat);
#endif /* CONFIG_BT_SMP_APP_PAIRING_ACCEPT */

	/** @brief Display a passkey to the user.
	 *
	 *  When called the application is expected to display the given
	 *  passkey to the user, with the expectation that the passkey will
	 *  then be entered on the peer device. The passkey will be in the
	 *  range of 0 - 999999, and is expected to be padded with zeroes so
	 *  that six digits are always shown. E.g. the value 37 should be
	 *  shown as 000037.
	 *
	 *  This callback may be set to NULL, which means that the local
	 *  device lacks the ability do display a passkey. If set
	 *  to non-NULL the cancel callback must also be provided, since
	 *  this is the only way the application can find out that it should
	 *  stop displaying the passkey.
	 *
	 *  @param conn Connection where pairing is currently active.
	 *  @param passkey Passkey to show to the user.
	 */
	void (*passkey_display)(struct bt_conn *conn, unsigned int passkey);

#if defined(CONFIG_BT_PASSKEY_KEYPRESS)
	/** @brief Receive Passkey Keypress Notification during pairing
	 *
	 *  This allows the remote device to use the local device to give users
	 *  feedback on the progress of entering the passkey over there. This is
	 *  useful when the remote device itself has no display suitable for
	 *  showing the progress.
	 *
	 *  The handler of this callback is expected to keep track of the number
	 *  of digits entered and show a password-field-like feedback to the
	 *  user.
	 *
	 *  This callback is only relevant while the local side does Passkey
	 *  Display.
	 *
	 *  The event type is verified to be in range of the enum. No other
	 *  sanitization has been done. The remote could send a large number of
	 *  events of any type in any order.
	 *
	 *  @param conn The related connection.
	 *  @param type Type of event. Verified in range of the enum.
	 */
	void (*passkey_display_keypress)(struct bt_conn *conn,
					 enum bt_conn_auth_keypress type);
#endif

	/** @brief Request the user to enter a passkey.
	 *
	 *  When called the user is expected to enter a passkey. The passkey
	 *  must be in the range of 0 - 999999, and should be expected to
	 *  be zero-padded, as that's how the peer device will typically be
	 *  showing it (e.g. 37 would be shown as 000037).
	 *
	 *  Once the user has entered the passkey its value should be given
	 *  to the stack using the bt_conn_auth_passkey_entry() API.
	 *
	 *  This callback may be set to NULL, which means that the local
	 *  device lacks the ability to enter a passkey. If set to non-NULL
	 *  the cancel callback must also be provided, since this is the
	 *  only way the application can find out that it should stop
	 *  requesting the user to enter a passkey.
	 *
	 *  @param conn Connection where pairing is currently active.
	 */
	void (*passkey_entry)(struct bt_conn *conn);

	/** @brief Request the user to confirm a passkey.
	 *
	 *  When called the user is expected to confirm that the given
	 *  passkey is also shown on the peer device.. The passkey will
	 *  be in the range of 0 - 999999, and should be zero-padded to
	 *  always be six digits (e.g. 37 would be shown as 000037).
	 *
	 *  Once the user has confirmed the passkey to match, the
	 *  bt_conn_auth_passkey_confirm() API should be called. If the
	 *  user concluded that the passkey doesn't match the
	 *  bt_conn_auth_cancel() API should be called.
	 *
	 *  This callback may be set to NULL, which means that the local
	 *  device lacks the ability to confirm a passkey. If set to non-NULL
	 *  the cancel callback must also be provided, since this is the
	 *  only way the application can find out that it should stop
	 *  requesting the user to confirm a passkey.
	 *
	 *  @param conn Connection where pairing is currently active.
	 *  @param passkey Passkey to be confirmed.
	 */
	void (*passkey_confirm)(struct bt_conn *conn, unsigned int passkey);

	/** @brief Request the user to provide Out of Band (OOB) data.
	 *
	 *  When called the user is expected to provide OOB data. The required
	 *  data are indicated by the information structure.
	 *
	 *  For LE Secure Connections OOB pairing, the user should provide
	 *  local OOB data, remote OOB data or both depending on their
	 *  availability. Their value should be given to the stack using the
	 *  bt_le_oob_set_sc_data() API.
	 *
	 *  This callback must be set to non-NULL in order to support OOB
	 *  pairing.
	 *
	 *  @param conn Connection where pairing is currently active.
	 *  @param info OOB pairing information.
	 */
	void (*oob_data_request)(struct bt_conn *conn,
				 struct bt_conn_oob_info *info);

	/** @brief Cancel the ongoing user request.
	 *
	 *  This callback will be called to notify the application that it
	 *  should cancel any previous user request (passkey display, entry
	 *  or confirmation).
	 *
	 *  This may be set to NULL, but must always be provided whenever the
	 *  passkey_display, passkey_entry passkey_confirm or pairing_confirm
	 *  callback has been provided.
	 *
	 *  @param conn Connection where pairing is currently active.
	 */
	void (*cancel)(struct bt_conn *conn);

	/** @brief Request confirmation for an incoming pairing.
	 *
	 *  This callback will be called to confirm an incoming pairing
	 *  request where none of the other user callbacks is applicable.
	 *
	 *  If the user decides to accept the pairing the
	 *  bt_conn_auth_pairing_confirm() API should be called. If the
	 *  user decides to reject the pairing the bt_conn_auth_cancel() API
	 *  should be called.
	 *
	 *  This callback may be set to NULL, which means that the local
	 *  device lacks the ability to confirm a pairing request. If set
	 *  to non-NULL the cancel callback must also be provided, since
	 *  this is the only way the application can find out that it should
	 *  stop requesting the user to confirm a pairing request.
	 *
	 *  @param conn Connection where pairing is currently active.
	 */
	void (*pairing_confirm)(struct bt_conn *conn);

#if defined(CONFIG_BT_CLASSIC)
	/** @brief Request the user to enter a passkey.
	 *
	 *  This callback will be called for a BR/EDR (Bluetooth Classic)
	 *  connection where pairing is being performed. Once called the
	 *  user is expected to enter a PIN code with a length between
	 *  1 and 16 digits. If the @a highsec parameter is set to true
	 *  the PIN code must be 16 digits long.
	 *
	 *  Once entered, the PIN code should be given to the stack using
	 *  the bt_conn_auth_pincode_entry() API.
	 *
	 *  This callback may be set to NULL, however in that case pairing
	 *  over BR/EDR will not be possible. If provided, the cancel
	 *  callback must be provided as well.
	 *
	 *  @param conn Connection where pairing is currently active.
	 *  @param highsec true if 16 digit PIN is required.
	 */
	void (*pincode_entry)(struct bt_conn *conn, bool highsec);
#endif

#if defined(CONFIG_BT_APP_PASSKEY)
	/** @brief Allow the application to provide a passkey for pairing.
	 *
	 *  If implemented, this callback allows the application to provide passkeys for pairing.
	 *  The valid range of passkeys is 0 - 999999. The application shall return the passkey for
	 *  pairing, or BT_PASSKEY_RAND to generate a random passkey. This callback is invoked only
	 *  for the Passkey Entry method as defined in Core Specification Vol. 3, Part H. Which
	 *  device in the pairing is showing the passkey depends on the IO capabilities of the
	 *  device; see Table 2.8 of the Bluetooth Core Specification V6.0, Vol. 3, Part H for more
	 *  details. For the purposes of this table, the device gains the "display" capability when
	 *  this callback is non-NULL. This is irrespective of whether the callback returns a
	 *  specified key or BT_PASSKEY_RAND.
	 *
	 *
	 *  @note When using this callback, it is the responsibility of the application to use
	 *        random and unique keys.
	 *
	 *  @param conn Connection where pairing is currently active.
	 *  @return Passkey for pairing, or BT_PASSKEY_RAND for the Host to generate a random
	 *          passkey.
	 */
	uint32_t (*app_passkey)(struct bt_conn *conn);
#endif /* CONFIG_BT_APP_PASSKEY */
};

/** Authenticated pairing information callback structure */
struct bt_conn_auth_info_cb {
	/** @brief notify that pairing procedure was complete.
	 *
	 *  This callback notifies the application that the pairing procedure
	 *  has been completed.
	 *
	 *  @param conn Connection object.
	 *  @param bonded Bond information has been distributed during the
	 *                pairing procedure.
	 */
	void (*pairing_complete)(struct bt_conn *conn, bool bonded);

	/** @brief notify that pairing process has failed.
	 *
	 *  @param conn Connection object.
	 *  @param reason Pairing failed reason
	 */
	void (*pairing_failed)(struct bt_conn *conn,
			       enum bt_security_err reason);

	/** @brief Notify that bond has been deleted.
	 *
	 *  This callback notifies the application that the bond information
	 *  for the remote peer has been deleted
	 *
	 *  @param id   Which local identity had the bond.
	 *  @param peer Remote address.
	 */
	void (*bond_deleted)(uint8_t id, const bt_addr_le_t *peer);

#if defined(CONFIG_BT_CLASSIC)
	/** @brief Notify that bond of classic has been deleted.
	 *
	 *  This callback notifies the application that the bond information of classic
	 *  for the remote peer has been deleted
	 *
	 *  @param peer Remote address.
	 */
	void (*br_bond_deleted)(const bt_addr_t *peer);
#endif /* CONFIG_BT_CLASSIC */

	/** Internally used field for list handling */
	sys_snode_t node;
};

/** @brief Register authentication callbacks.
 *
 *  Register callbacks to handle authenticated pairing. Passing NULL
 *  unregisters a previous callbacks structure.
 *
 *  @param cb Callback struct.
 *
 *  @return Zero on success or negative error code otherwise
 */
int bt_conn_auth_cb_register(const struct bt_conn_auth_cb *cb);

/** @brief Overlay authentication callbacks used for a given connection.
 *
 *  This function can be used only for Bluetooth LE connections.
 *  The @kconfig{CONFIG_BT_SMP} must be enabled for this function.
 *
 *  The authentication callbacks for a given connection cannot be overlaid if
 *  security procedures in the SMP module have already started. This function
 *  can be called only once per connection.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *  @param cb	Callback struct.
 *
 *  @return Zero on success or negative error code otherwise
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_auth_cb_overlay(struct bt_conn *conn, const struct bt_conn_auth_cb *cb);

/** @brief Register authentication information callbacks.
 *
 *  Register callbacks to get authenticated pairing information. Multiple
 *  registrations can be done.
 *
 *  @param cb Callback struct.
 *
 *  @return Zero on success or negative error code otherwise
 */
int bt_conn_auth_info_cb_register(struct bt_conn_auth_info_cb *cb);

/** @brief Unregister authentication information callbacks.
 *
 *  Unregister callbacks to stop getting authenticated pairing information.
 *
 *  @param cb Callback struct.
 *
 *  @return Zero on success or negative error code otherwise
 */
int bt_conn_auth_info_cb_unregister(struct bt_conn_auth_info_cb *cb);

/** @brief Reply with entered passkey.
 *
 *  This function should be called only after passkey_entry callback from
 *  bt_conn_auth_cb structure was called.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *  @param passkey Entered passkey.
 *
 *  @return Zero on success or negative error code otherwise
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_auth_passkey_entry(struct bt_conn *conn, unsigned int passkey);

/** @brief Send Passkey Keypress Notification during pairing
 *
 *  This function may be called only after passkey_entry callback from
 *  bt_conn_auth_cb structure was called.
 *
 *  Requires @kconfig{CONFIG_BT_PASSKEY_KEYPRESS}.
 *
 *  @param conn @ref BT_CONN_TYPE_LE destination connection for the notification.
 *  @param type What keypress event type to send. @see bt_conn_auth_keypress.
 *
 *  @retval 0 Success
 *  @retval -EINVAL Improper use of the API.
 *  @retval -ENOMEM Failed to allocate.
 *  @retval -ENOBUFS Failed to allocate.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE connection
 */
int bt_conn_auth_keypress_notify(struct bt_conn *conn, enum bt_conn_auth_keypress type);

/** @brief Cancel ongoing authenticated pairing.
 *
 *  This function allows to cancel ongoing authenticated pairing.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *
 *  @return Zero on success or negative error code otherwise
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_auth_cancel(struct bt_conn *conn);

/** @brief Reply if passkey was confirmed to match by user.
 *
 *  This function should be called only after passkey_confirm callback from
 *  bt_conn_auth_cb structure was called.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *
 *  @return Zero on success or negative error code otherwise
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_auth_passkey_confirm(struct bt_conn *conn);

/** @brief Reply if incoming pairing was confirmed by user.
 *
 *  This function should be called only after pairing_confirm callback from
 *  bt_conn_auth_cb structure was called if user confirmed incoming pairing.
 *
 *  @param conn @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection object.
 *
 *  @return Zero on success or negative error code otherwise
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_LE or @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_auth_pairing_confirm(struct bt_conn *conn);

/** @brief Reply with entered PIN code.
 *
 *  This function should be called only after PIN code callback from
 *  bt_conn_auth_cb structure was called. It's for legacy 2.0 devices.
 *
 *  @param conn @ref BT_CONN_TYPE_BR connection object.
 *  @param pin Entered PIN code.
 *
 *  @return Zero on success or negative error code otherwise
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_auth_pincode_entry(struct bt_conn *conn, const char *pin);

/** Connection parameters for BR/EDR connections */
struct bt_br_conn_param {
	bool allow_role_switch;
};

/** @brief Initialize BR/EDR connection parameters
 *
 *  @param role_switch True if role switch is allowed
 */
#define BT_BR_CONN_PARAM_INIT(role_switch) \
{ \
	.allow_role_switch = (role_switch), \
}

/** Helper to declare BR/EDR connection parameters inline
  *
  * @param role_switch True if role switch is allowed
  */
#define BT_BR_CONN_PARAM(role_switch) \
	((struct bt_br_conn_param[]) { \
		BT_BR_CONN_PARAM_INIT(role_switch) \
	 })

/** Default BR/EDR connection parameters:
 *    Role switch allowed
 */
#define BT_BR_CONN_PARAM_DEFAULT BT_BR_CONN_PARAM(true)


/** @brief Initiate an BR/EDR connection to a remote device.
 *
 *  Allows initiate new BR/EDR link to remote peer using its address.
 *
 *  The caller gets a new reference to the connection object which must be
 *  released with bt_conn_unref() once done using the object.
 *
 *  @param peer  Remote address.
 *  @param param Initial connection parameters.
 *
 *  @return Valid connection object on success or NULL otherwise.
 */
struct bt_conn *bt_conn_create_br(const bt_addr_t *peer,
				  const struct bt_br_conn_param *param);

/** @brief Look up an existing BR connection by address.
 *
 *  Look up an existing BR connection based on the remote address.
 *
 *  The caller gets a new reference to the connection object which must be
 *  released with bt_conn_unref() once done using the object.
 *
 *  @param peer Remote address.
 *
 *  @return Connection object or NULL if not found.
 */
struct bt_conn *bt_conn_lookup_addr_br(const bt_addr_t *peer);

/** @brief Get destination (peer) address of a connection.
 *
 *  @param conn Connection object.
 *
 *  @return Destination address if @p conn is a valid @ref BT_CONN_TYPE_BR connection
 */
const bt_addr_t *bt_conn_get_dst_br(const struct bt_conn *conn);

/** @brief Change the role of the conn.
 *
 *  @param conn Connection object.
 *  @param role The role that want to switch as, the value is @ref BT_HCI_ROLE_CENTRAL and
 *              @ref BT_HCI_ROLE_PERIPHERAL from hci_types.h.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -ENOBUFS HCI command buffer is not available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_BR connection
 */
int bt_conn_br_switch_role(const struct bt_conn *conn, uint8_t role);

/** @brief Enable/disable role switch of the connection by setting the connection's link policy.
 *
 *  @param conn Connection object.
 *  @param enable Value enable/disable role switch of controller.
 *
 *  @return Zero on success or (negative) error code on failure.
 *  @return -ENOBUFS HCI command buffer is not available.
 *  @return -EINVAL @p conn is not a valid @ref BT_CONN_TYPE_BR connection.
 */
int bt_conn_br_set_role_switch_enable(const struct bt_conn *conn, bool enable);

#if defined(CONFIG_BT_POWER_MODE_CONTROL)
/** @brief bluetooth conn check and enter sniff mode
 *
 *  This function is used to identify which ACL link connection is to
 *  be placed in Sniff mode
 *
 *  @param conn bt_conn conn
 *  @param min_interval Minimum sniff interval.
 *  @param max_interval Maxmum sniff interval.
 *  @param attempt Number of Baseband receive slots for sniff attempt.
 *  @param timeout Number of Baseband receive slots for sniff timeout.
 */
int bt_conn_br_enter_sniff_mode(struct bt_conn *conn, uint16_t min_interval,
				 uint16_t max_interval, uint16_t attempt, uint16_t timeout);

/** @brief bluetooth conn check and exit sniff mode
 *
 *  @param conn bt_conn conn
 *
 *  @return  Zero for success, non-zero otherwise.
 */
int bt_conn_br_exit_sniff_mode(struct bt_conn *conn);
#endif /* CONFIG_BT_POWER_MODE_CONTROL */

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif /* ZEPHYR_INCLUDE_BLUETOOTH_CONN_H_ */