ble_conn_state.h

00001 /*
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00032 
00033 /**
00034  * @file
00035  *
00036  * @defgroup ble_conn_state Connection state
00037  * @ingroup ble_sdk_lib
00038  * @{
00039  * @brief Module for storing data on BLE connections.
00040  *
00041  * @details This module stores certain states for each connection, which can be queried by
00042  *          connection handle. The module uses BLE events to keep the states updated.
00043  *
00044  *          In addition to the preprogrammed states, this module can also keep track of a number of
00045  *          binary user states, or <i>user flags</i>. These are reset to 0 for new connections, but
00046  *          otherwise not touched by this module.
00047  *
00048  *          This module uses the @ref sdk_mapped_flags module, with connection handles as keys and
00049  *          the connection states as flags.
00050  *
00051  * @note A connection handle is not immediately invalidated when it is disconnected. Certain states,
00052  *       such as the role, can still be queried until the next time a new connection is established
00053  *       to any device.
00054  *
00055  *          To function properly, this module must be provided with BLE events from the SoftDevice
00056  *          through the @ref ble_conn_state_on_ble_evt() function. This module should be the first
00057  *          to receive BLE events if they are dispatched to multiple modules.
00058  */
00059 
00060 #ifndef BLE_CONN_STATE_H__
00061 #define BLE_CONN_STATE_H__
00062 
00063 #include <stdbool.h>
00064 #include <stdint.h>
00065 #include "ble.h"
00066 #include "sdk_mapped_flags.h "
00067 
00068 /**@brief Connection handle statuses.
00069  */
00070 typedef enum
00071 {
00072     BLE_CONN_STATUS_INVALID,       /**< The connection handle is invalid. */
00073     BLE_CONN_STATUS_DISCONNECTED,  /**< The connection handle refers to a connection that has been disconnected, but not yet invalidated. */
00074     BLE_CONN_STATUS_CONNECTED,     /**< The connection handle refers to an active connection. */
00075 } ble_conn_state_status_t;
00076 
00077 #define BLE_CONN_STATE_N_USER_FLAGS 16  /**< The number of available user flags. */
00078 
00079 
00080 /**@brief One ID for each user flag collection.
00081  *
00082  * @details These IDs are used to identify user flag collections in the API calls.
00083  */
00084 typedef enum
00085 {
00086     BLE_CONN_STATE_USER_FLAG0 = 0,
00087     BLE_CONN_STATE_USER_FLAG1,
00088     BLE_CONN_STATE_USER_FLAG2,
00089     BLE_CONN_STATE_USER_FLAG3,
00090     BLE_CONN_STATE_USER_FLAG4,
00091     BLE_CONN_STATE_USER_FLAG5,
00092     BLE_CONN_STATE_USER_FLAG6,
00093     BLE_CONN_STATE_USER_FLAG7,
00094     BLE_CONN_STATE_USER_FLAG8,
00095     BLE_CONN_STATE_USER_FLAG9,
00096     BLE_CONN_STATE_USER_FLAG10,
00097     BLE_CONN_STATE_USER_FLAG11,
00098     BLE_CONN_STATE_USER_FLAG12,
00099     BLE_CONN_STATE_USER_FLAG13,
00100     BLE_CONN_STATE_USER_FLAG14,
00101     BLE_CONN_STATE_USER_FLAG15,
00102     BLE_CONN_STATE_USER_FLAG_INVALID,
00103 } ble_conn_state_user_flag_id_t;
00104 
00105 
00106 /**
00107  * @defgroup ble_conn_state_functions BLE connection state functions
00108  * @{
00109  */
00110 
00111 
00112 /**@brief Function for initializing or resetting the module.
00113  *
00114  * @details This function sets all states to their default, removing all records of connection handles.
00115  */
00116 void ble_conn_state_init(void);
00117 
00118 
00119 /**@brief Function for providing BLE SoftDevice events to the connection state module.
00120  *
00121  * @param[in]  p_ble_evt    The SoftDevice event.
00122  */
00123 void ble_conn_state_on_ble_evt(ble_evt_t * p_ble_evt);
00124 
00125 
00126 /**@brief Function for querying whether a connection handle represents a valid connection.
00127  *
00128  * @details A connection might be valid and have a BLE_CONN_STATUS_DISCONNECTED status.
00129  *          Those connections are invalidated after a new connection occurs.
00130  *
00131  * @param[in]  conn_handle  Handle of the connection.
00132  *
00133  * @retval true   If conn_handle represents a valid connection, thus a connection for which
00134                   we have a record.
00135  * @retval false  If conn_handle is @ref BLE_GAP_ROLE_INVALID, or if it has never been recorded.
00136  */
00137 bool ble_conn_state_valid(uint16_t conn_handle);
00138 
00139 
00140 /**@brief Function for querying the role of the local device in a connection.
00141  *
00142  * @param[in]  conn_handle  Handle of the connection to get the role for.
00143  *
00144  * @return  The role of the local device in the connection (see @ref BLE_GAP_ROLES).
00145  *          If conn_handle is not valid, the function returns BLE_GAP_ROLE_INVALID.
00146  */
00147 uint8_t ble_conn_state_role(uint16_t conn_handle);
00148 
00149 
00150 /**@brief Function for querying the status of a connection.
00151  *
00152  * @param[in]  conn_handle  Handle of the connection.
00153  *
00154  * @return  The status of the connection.
00155  *          If conn_handle is not valid, the function returns BLE_CONN_STATE_INVALID.
00156  */
00157 ble_conn_state_status_t ble_conn_state_status(uint16_t conn_handle);
00158 
00159 
00160 /**@brief Function for querying whether a connection is encrypted.
00161  *
00162  * @param[in]  conn_handle  Handle of connection to get the encryption state for.
00163  *
00164  * @retval true   If the connection is encrypted.
00165  * @retval false  If the connection is not encrypted or conn_handle is invalid.
00166  */
00167 bool ble_conn_state_encrypted(uint16_t conn_handle);
00168 
00169 
00170 /**@brief Function for querying whether a connection encryption is protected from Man in the Middle
00171  *        attacks.
00172  *
00173  * @param[in]  conn_handle  Handle of connection to get the MITM state for.
00174  *
00175  * @retval true   If the connection is encrypted with MITM protection.
00176  * @retval false  If the connection is not encrypted, or encryption is not MITM protected, or
00177  *                conn_handle is invalid.
00178  */
00179 bool ble_conn_state_mitm_protected(uint16_t conn_handle);
00180 
00181 
00182 /**@brief Function for querying the total number of connections.
00183  *
00184  * @return  The total number of valid connections for which the module has a record.
00185  */
00186 uint32_t ble_conn_state_n_connections(void);
00187 
00188 
00189 /**@brief Function for querying the total number of connections in which the role of the local
00190  *        device is @ref BLE_GAP_ROLE_CENTRAL.
00191  *
00192  * @return  The number of connections in which the role of the local device is
00193  *          @ref BLE_GAP_ROLE_CENTRAL.
00194  */
00195 uint32_t ble_conn_state_n_centrals(void);
00196 
00197 
00198 /**@brief Function for querying the total number of connections in which the role of the local
00199  *        device is @ref BLE_GAP_ROLE_PERIPH.
00200  *
00201  * @return  The number of connections in which the role of the local device is
00202  *          @ref BLE_GAP_ROLE_PERIPH.
00203  */
00204 uint32_t ble_conn_state_n_peripherals(void);
00205 
00206 
00207 /**@brief Function for obtaining a list of all connection handles for which the module has a record.
00208  *
00209  * @details This function takes into account connections whose state is BLE_CONN_STATUS_DISCONNECTED.
00210  *
00211  * @return  A list of all valid connection handles for which the module has a record.
00212  */
00213 sdk_mapped_flags_key_list_t ble_conn_state_conn_handles(void);
00214 
00215 
00216 /**@brief Function for obtaining a list of connection handles in which the role of the local
00217  *        device is @ref BLE_GAP_ROLE_CENTRAL.
00218  *
00219  * @details This function takes into account connections whose state is BLE_CONN_STATUS_DISCONNECTED.
00220  *
00221  * @return  A list of all valid connection handles for which the module has a record and in which
00222  *          the role of local device is @ref BLE_GAP_ROLE_CENTRAL.
00223  */
00224 sdk_mapped_flags_key_list_t ble_conn_state_central_handles(void);
00225 
00226 
00227 /**@brief Function for obtaining the handle for the connection in which the role of the local device
00228  *        is @ref BLE_GAP_ROLE_PERIPH.
00229  *
00230  * @details This function takes into account connections whose state is BLE_CONN_STATUS_DISCONNECTED.
00231  *
00232  * @return  A list of all valid connection handles for which the module has a record and in which
00233  *          the role of local device is @ref BLE_GAP_ROLE_PERIPH.
00234  */
00235 sdk_mapped_flags_key_list_t ble_conn_state_periph_handles(void);
00236 
00237 
00238 /**@brief Function for obtaining exclusive access to one of the user flag collections.
00239  *
00240  * @details The acquired collection contains one flag for each connection. These flags can be set
00241  *          and read individually for each connection.
00242  *
00243  *          The state of user flags will not be modified by the connection state module, except to
00244  *          set it to 0 for a connection when that connection is invalidated.
00245  *
00246  * @return  The ID of the acquired flag, or BLE_CONN_STATE_USER_FLAG_INVALID if none are available.
00247  */
00248 ble_conn_state_user_flag_id_t ble_conn_state_user_flag_acquire(void);
00249 
00250 
00251 /**@brief Function for reading the value of a user flag.
00252  *
00253  * @param[in]  conn_handle  Handle of connection to get the flag state for.
00254  * @param[in]  flag_id      Which flag to get the state for.
00255  *
00256  * @return  The state of the flag. If conn_handle is invalid, the function returns false.
00257  */
00258 bool ble_conn_state_user_flag_get(uint16_t conn_handle, ble_conn_state_user_flag_id_t flag_id);
00259 
00260 
00261 /**@brief Function for setting the value of a user flag.
00262  *
00263  * @param[in]  conn_handle  Handle of connection to set the flag state for.
00264  * @param[in]  flag_id      Which flag to set the state for.
00265  * @param[in]  value        Value to set the flag state to.
00266  */
00267 void ble_conn_state_user_flag_set(uint16_t                      conn_handle,
00268                                   ble_conn_state_user_flag_id_t flag_id,
00269                                   bool                          value);
00270 
00271 
00272 /**@brief Function for getting the state of a user flag for all connection handles.
00273  *
00274  * @details The returned collection can be used with the @ref sdk_mapped_flags API. The returned
00275  *          collection is a copy, so modifying it has no effect on the conn_state module.
00276  *
00277  * @param[in]  flag_id  Which flag to get states for.
00278  *
00279  * @return  The collection of flag states. The collection is always all zeros when the flag_id is
00280  *          unregistered.
00281  */
00282 sdk_mapped_flags_t ble_conn_state_user_flag_collection(ble_conn_state_user_flag_id_t flag_id);
00283 
00284 /** @} */
00285 /** @} */
00286 
00287 #endif /* BLE_CONN_STATE_H__ */