517 lines
15 KiB
C
517 lines
15 KiB
C
/** @file
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* @brief Bluetooth connection handling
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*/
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/*
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* Copyright (c) 2015-2016 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef __BT_CONN_H
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#define __BT_CONN_H
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/**
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* @brief Connection management
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* @defgroup bt_conn Connection management
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* @ingroup bluetooth
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* @{
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <stdbool.h>
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#include <bluetooth/bluetooth.h>
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#include <bluetooth/hci.h>
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/** Opaque type representing a connection to a remote device */
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struct bt_conn;
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/** Connection parameters for LE connections */
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struct bt_le_conn_param {
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u16_t interval_min;
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u16_t interval_max;
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u16_t latency;
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u16_t timeout;
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};
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/** Helper to declare connection parameters inline
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*
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* @param int_min Minimum Connection Interval (N * 1.25 ms)
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* @param int_max Maximum Connection Interval (N * 1.25 ms)
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* @param lat Connection Latency
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* @param to Supervision Timeout (N * 10 ms)
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*/
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#define BT_LE_CONN_PARAM(int_min, int_max, lat, to) \
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(&(struct bt_le_conn_param) { \
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.interval_min = (int_min), \
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.interval_max = (int_max), \
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.latency = (lat), \
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.timeout = (to), \
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})
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/** Default LE connection parameters:
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* Connection Interval: 30-50 ms
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* Latency: 0
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* Timeout: 4 s
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*/
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#define BT_LE_CONN_PARAM_DEFAULT BT_LE_CONN_PARAM(BT_GAP_INIT_CONN_INT_MIN, \
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BT_GAP_INIT_CONN_INT_MAX, \
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0, 400)
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/** @brief Increment a connection's reference count.
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*
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* Increment the reference count of a connection object.
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*
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* @param conn Connection object.
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*
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* @return Connection object with incremented reference count.
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*/
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struct bt_conn *bt_conn_ref(struct bt_conn *conn);
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/** @brief Decrement a connection's reference count.
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*
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* Decrement the reference count of a connection object.
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*
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* @param conn Connection object.
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*/
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void bt_conn_unref(struct bt_conn *conn);
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/** @brief Look up an existing connection by address.
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*
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* Look up an existing connection based on the remote address.
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*
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* @param peer Remote address.
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*
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* @return Connection object or NULL if not found. The caller gets a
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* new reference to the connection object which must be released with
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* bt_conn_unref() once done using the object.
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*/
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struct bt_conn *bt_conn_lookup_addr_le(const bt_addr_le_t *peer);
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/** @brief Get destination (peer) address of a connection.
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*
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* @param conn Connection object.
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*
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* @return Destination address.
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*/
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const bt_addr_le_t *bt_conn_get_dst(const struct bt_conn *conn);
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/** Connection Type */
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enum {
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/** LE Connection Type */
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BT_CONN_TYPE_LE,
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/** BR/EDR Connection Type */
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BT_CONN_TYPE_BR,
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/** SCO Connection Type */
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BT_CONN_TYPE_SCO,
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};
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/** LE Connection Info Structure */
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struct bt_conn_le_info {
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const bt_addr_le_t *src; /** Source Address */
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const bt_addr_le_t *dst; /** Destination Address */
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u16_t interval; /** Connection interval */
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u16_t latency; /** Connection slave latency */
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u16_t timeout; /** Connection supervision timeout */
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};
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/** BR/EDR Connection Info Structure */
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struct bt_conn_br_info {
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const bt_addr_t *dst; /** Destination BR/EDR address */
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};
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/** Connection role (master or slave) */
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enum {
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BT_CONN_ROLE_MASTER,
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BT_CONN_ROLE_SLAVE,
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};
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/** @brief Connection Info Structure
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*
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*
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* @param type Connection Type
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* @param role Connection Role
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* @param le LE Connection specific Info
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* @param br BR/EDR Connection specific Info
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*/
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struct bt_conn_info {
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u8_t type;
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u8_t role;
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union {
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struct bt_conn_le_info le;
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struct bt_conn_br_info br;
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};
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};
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/** @brief Get connection info
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*
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* @param conn Connection object.
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* @param info Connection info object.
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*
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* @return Zero on success or (negative) error code on failure.
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*/
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int bt_conn_get_info(const struct bt_conn *conn, struct bt_conn_info *info);
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/** @brief Update the connection parameters.
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*
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* @param conn Connection object.
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* @param param Updated connection parameters.
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*
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* @return Zero on success or (negative) error code on failure.
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*/
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int bt_conn_le_param_update(struct bt_conn *conn,
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const struct bt_le_conn_param *param);
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/** @brief Disconnect from a remote device or cancel pending connection.
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*
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* Disconnect an active connection with the specified reason code or cancel
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* pending outgoing connection.
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*
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* @param conn Connection to disconnect.
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* @param reason Reason code for the disconnection.
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*
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* @return Zero on success or (negative) error code on failure.
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*/
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int bt_conn_disconnect(struct bt_conn *conn, u8_t reason);
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/** @brief Initiate an LE connection to a remote device.
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*
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* Allows initiate new LE link to remote peer using its address.
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* Returns a new reference that the the caller is responsible for managing.
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*
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* @param peer Remote address.
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* @param param Initial connection parameters.
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*
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* @return Valid connection object on success or NULL otherwise.
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*/
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struct bt_conn *bt_conn_create_le(const bt_addr_le_t *peer,
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const struct bt_le_conn_param *param);
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/** @brief Automatically connect to remote device if it's in range.
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*
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* This function enables/disables automatic connection initiation.
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* Every time the device loses the connection with peer, this connection
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* will be re-established if connectable advertisement from peer is received.
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*
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* @param addr Remote Bluetooth address.
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* @param param If non-NULL, auto connect is enabled with the given
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* parameters. If NULL, auto connect is disabled.
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*
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* @return Zero on success or error code otherwise.
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*/
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int bt_le_set_auto_conn(bt_addr_le_t *addr,
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const struct bt_le_conn_param *param);
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/** @brief Initiate directed advertising to a remote device
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*
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* Allows initiating a new LE connection to remote peer with the remote
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* acting in central role and the local device in peripheral role.
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*
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* The advertising type must be either BT_LE_ADV_DIRECT_IND or
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* BT_LE_ADV_DIRECT_IND_LOW_DUTY.
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*
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* In case of high duty cycle this will result in a callback with
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* connected() with a new connection or with an error.
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*
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* The advertising may be canceled with bt_conn_disconnect().
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*
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* Returns a new reference that the the caller is responsible for managing.
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*
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* @param peer Remote address.
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* @param param Directed advertising parameters.
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*
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* @return Valid connection object on success or NULL otherwise.
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*/
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struct bt_conn *bt_conn_create_slave_le(const bt_addr_le_t *peer,
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const struct bt_le_adv_param *param);
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/** Security level. */
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typedef enum __packed {
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/** Only for BR/EDR special cases, like SDP */
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BT_SECURITY_NONE,
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/** No encryption and no authentication. */
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BT_SECURITY_LOW,
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/** Encryption and no authentication (no MITM). */
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BT_SECURITY_MEDIUM,
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/** Encryption and authentication (MITM). */
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BT_SECURITY_HIGH,
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/** Authenticated Secure Connections */
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BT_SECURITY_FIPS,
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} bt_security_t;
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/** @brief Set security level for a connection.
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*
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* This function enable security (encryption) for a connection. If device is
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* already paired with sufficiently strong key encryption will be enabled. If
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* link is already encrypted with sufficiently strong key this function does
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* nothing.
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*
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* If device is not paired pairing will be initiated. If device is paired and
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* keys are too weak but input output capabilities allow for strong enough keys
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* pairing will be initiated.
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*
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* This function may return error if required level of security is not possible
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* to achieve due to local or remote device limitation (eg input output
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* capabilities).
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*
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* @param conn Connection object.
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* @param sec Requested security level.
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*
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* @return 0 on success or negative error
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*/
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int bt_conn_security(struct bt_conn *conn, bt_security_t sec);
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/** @brief Get encryption key size.
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*
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* This function gets encryption key size.
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* If there is no security (encryption) enabled 0 will be returned.
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*
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* @param conn Existing connection object.
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*
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* @return Encryption key size.
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*/
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u8_t bt_conn_enc_key_size(struct bt_conn *conn);
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/** @brief Connection callback structure.
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*
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* This structure is used for tracking the state of a connection.
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* It is registered with the help of the bt_conn_cb_register() API.
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* It's permissible to register multiple instances of this @ref bt_conn_cb
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* type, in case different modules of an application are interested in
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* tracking the connection state. If a callback is not of interest for
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* an instance, it may be set to NULL and will as a consequence not be
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* used for that instance.
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*/
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struct bt_conn_cb {
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/** @brief A new connection has been established.
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*
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* This callback notifies the application of a new connection.
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* In case the err parameter is non-zero it means that the
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* connection establishment failed.
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*
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* @param conn New connection object.
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* @param err HCI error. Zero for success, non-zero otherwise.
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*/
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void (*connected)(struct bt_conn *conn, u8_t err);
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/** @brief A connection has been disconnected.
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*
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* This callback notifies the application that a connection
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* has been disconnected.
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*
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* @param conn Connection object.
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* @param reason HCI reason for the disconnection.
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*/
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void (*disconnected)(struct bt_conn *conn, u8_t reason);
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/** @brief LE connection parameter update request.
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*
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* This callback notifies the application that a remote device
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* is requesting to update the connection parameters. The
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* application accepts the parameters by returning true, or
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* rejects them by returning false. Before accepting, the
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* application may also adjust the parameters to better suit
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* its needs.
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*
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* It is recommended for an application to have just one of these
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* callbacks for simplicity. However, if an application registers
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* multiple it needs to manage the potentially different
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* requirements for each callback. Each callback gets the
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* parameters as returned by previous callbacks, i.e. they are not
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* necessarily the same ones as the remote originally sent.
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*
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* @param conn Connection object.
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* @param param Proposed connection parameters.
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*
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* @return true to accept the parameters, or false to reject them.
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*/
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bool (*le_param_req)(struct bt_conn *conn,
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struct bt_le_conn_param *param);
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/** @brief The parameters for an LE connection have been updated.
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*
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* This callback notifies the application that the connection
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* parameters for an LE connection have been updated.
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*
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* @param conn Connection object.
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* @param interval Connection interval.
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* @param latency Connection latency.
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* @param timeout Connection supervision timeout.
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*/
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void (*le_param_updated)(struct bt_conn *conn, u16_t interval,
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u16_t latency, u16_t timeout);
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#if defined(CONFIG_BLUETOOTH_SMP)
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/** @brief Remote Identity Address has been resolved.
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*
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* This callback notifies the application that a remote
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* Identity Address has been resolved
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*
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* @param conn Connection object.
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* @param rpa Resolvable Private Address.
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* @param identity Identity Address.
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*/
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void (*identity_resolved)(struct bt_conn *conn,
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const bt_addr_le_t *rpa,
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const bt_addr_le_t *identity);
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#endif /* CONFIG_BLUETOOTH_SMP */
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#if defined(CONFIG_BLUETOOTH_SMP) || defined(CONFIG_BLUETOOTH_BREDR)
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/** @brief The security level of a connection has changed.
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*
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* This callback notifies the application that the security level
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* of a connection has changed.
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*
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* @param conn Connection object.
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* @param level New security level of the connection.
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*/
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void (*security_changed)(struct bt_conn *conn, bt_security_t level);
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#endif /* defined(CONFIG_BLUETOOTH_SMP) || defined(CONFIG_BLUETOOTH_BREDR) */
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struct bt_conn_cb *_next;
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};
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/** @brief Register connection callbacks.
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*
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* Register callbacks to monitor the state of connections.
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*
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* @param cb Callback struct.
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*/
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void bt_conn_cb_register(struct bt_conn_cb *cb);
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/** Authenticated pairing callback structure */
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struct bt_conn_auth_cb {
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void (*passkey_display)(struct bt_conn *conn, unsigned int passkey);
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void (*passkey_entry)(struct bt_conn *conn);
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void (*passkey_confirm)(struct bt_conn *conn, unsigned int passkey);
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void (*cancel)(struct bt_conn *conn);
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void (*pairing_confirm)(struct bt_conn *conn);
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#if defined(CONFIG_BLUETOOTH_BREDR)
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void (*pincode_entry)(struct bt_conn *conn, bool highsec);
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#endif
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};
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/** @brief Register authentication callbacks.
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*
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* Register callbacks to handle authenticated pairing. Passing NULL unregisters
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* previous callbacks structure.
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*
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* @param cb Callback struct.
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*
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* @return Zero on success or negative error code otherwise
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*/
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int bt_conn_auth_cb_register(const struct bt_conn_auth_cb *cb);
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/** @brief Reply with entered passkey.
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*
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* This function should be called only after passkey_entry callback from
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* bt_conn_auth_cb structure was called.
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*
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* @param conn Connection object.
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* @param passkey Entered passkey.
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*
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* @return Zero on success or negative error code otherwise
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*/
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int bt_conn_auth_passkey_entry(struct bt_conn *conn, unsigned int passkey);
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/** @brief Cancel ongoing authenticated pairing.
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*
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* This function allows to cancel ongoing authenticated pairing.
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*
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* @param conn Connection object.
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*
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* @return Zero on success or negative error code otherwise
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*/
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int bt_conn_auth_cancel(struct bt_conn *conn);
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/** @brief Reply if passkey was confirmed to match by user.
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*
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* This function should be called only after passkey_confirm callback from
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* bt_conn_auth_cb structure was called.
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*
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* @param conn Connection object.
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*
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* @return Zero on success or negative error code otherwise
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*/
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int bt_conn_auth_passkey_confirm(struct bt_conn *conn);
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/** @brief Reply if incoming pairing was confirmed by user.
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*
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* This function should be called only after pairing_confirm callback from
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* bt_conn_auth_cb structure was called if user confirmed incoming pairing.
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*
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* @param conn Connection object.
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*
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* @return Zero on success or negative error code otherwise
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*/
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int bt_conn_auth_pairing_confirm(struct bt_conn *conn);
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/** @brief Reply with entered PIN code.
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*
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* This function should be called only after PIN code callback from
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* bt_conn_auth_cb structure was called. It's for legacy 2.0 devices.
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*
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* @param conn Connection object.
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* @param pin Entered PIN code.
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*
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* @return Zero on success or negative error code otherwise
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*/
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int bt_conn_auth_pincode_entry(struct bt_conn *conn, const char *pin);
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/** Connection parameters for BR/EDR connections */
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struct bt_br_conn_param {
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bool allow_role_switch;
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};
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/** Helper to declare BR/EDR connection parameters inline
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*
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* @param role_switch True if role switch is allowed
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*/
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#define BT_BR_CONN_PARAM(role_switch) \
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(&(struct bt_br_conn_param) { \
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.allow_role_switch = (role_switch), \
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})
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/** Default BR/EDR connection parameters:
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* Role switch allowed
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*/
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#define BT_BR_CONN_PARAM_DEFAULT BT_BR_CONN_PARAM(true)
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/** @brief Initiate an BR/EDR connection to a remote device.
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*
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* Allows initiate new BR/EDR link to remote peer using its address.
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* Returns a new reference that the the caller is responsible for managing.
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*
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* @param peer Remote address.
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* @param param Initial connection parameters.
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*
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* @return Valid connection object on success or NULL otherwise.
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*/
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struct bt_conn *bt_conn_create_br(const bt_addr_t *peer,
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const struct bt_br_conn_param *param);
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/** @brief Initiate an SCO connection to a remote device.
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*
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* Allows initiate new SCO link to remote peer using its address.
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* Returns a new reference that the the caller is responsible for managing.
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*
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* @param peer Remote address.
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*
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* @return Valid connection object on success or NULL otherwise.
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*/
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struct bt_conn *bt_conn_create_sco(const bt_addr_t *peer);
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#ifdef __cplusplus
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}
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#endif
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/**
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* @}
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*/
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#endif /* __BT_CONN_H */
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