Mbed OS Reference | Gap.h Source File

 /* mbed Microcontroller Library
  * Copyright (c) 2006-2020 ARM Limited
  *
  * SPDX-License-Identifier: Apache-2.0
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 #ifndef BLE_GAP_GAP_H
 #define BLE_GAP_GAP_H
 
 #include "ble/common/CallChainOfFunctionPointersWithContext.h"
 
 #include "ble/common/BLERoles.h"
 #include "ble/common/BLETypes.h"
 #include "ble/gap/AdvertisingDataBuilder.h"
 #include "ble/gap/AdvertisingDataParser.h"
 #include "ble/gap/AdvertisingDataSimpleBuilder.h"
 #include "ble/gap/AdvertisingDataTypes.h"
 #include "ble/gap/AdvertisingParameters.h"
 #include "ble/gap/ConnectionParameters.h"
 #include "ble/gap/ScanParameters.h"
 #include "ble/gap/Events.h"
 #include "ble/gap/Types.h"
 
 namespace ble {
 
 #if !defined(DOXYGEN_ONLY)
 namespace impl {
 class Gap;
 }
 #endif // !defined(DOXYGEN_ONLY)
 
 /**
  * @addtogroup ble
  * @{
  * @addtogroup gap
  * @{
  */
 
 /**
  * Define device discovery, connection and link management procedures.
  *
  * - Device discovery: A device can advertise to nearby peers its existence,
  * identity and capabilities. Similarly, a device can scan its environment to
  * find advertising peers. The information acquired during the scan helps to
  * identify peers and understand their use. A scanner may acquire more information
  * about an advertising peer by sending a scan request. If the peer accepts scan
  * requests, it may reply with additional information about its state.
  *
  * - Connection: A bluetooth device can establish a connection to a connectable
  * advertising peer. Once the connection is established, both devices can
  * communicate using the GATT protocol. The GATT protocol allows connected
  * devices to expose a set of states that the other peer can discover, read and write.
  *
  * - Link Management: Connected devices may drop the connection and may adjust
  * connection parameters according to the power envelop needed for their
  * application.
  *
  * @par Accessing gap
  *
  * Instance of a Gap class for a given BLE device should be accessed using
  * BLE::gap(). The reference returned remains valid until the BLE instance
  * shut down (see BLE::shutdown()).
  *
  * @code
  * // assuming ble_device has been initialized
  * BLE& ble_device;
  *
  * ble::Gap& gap = ble_device.gap();
  * @endcode
  *
  * @par Advertising
  *
  * Advertising consists of broadcasting at a regular interval a small amount of
  * data containing valuable information about the device. These packets may be
  * scanned by peer devices listening on BLE advertising channels.
  *
  * Scanners may also request additional information from a device advertising by
  * sending a scan request. If the broadcaster accepts scan requests, it can reply
  * with a scan response packet containing additional information.
  *
  * Advertising parameters are updated using setAdvertisingParams(). The main
  * advertising payload is updated using setAdvertisingPayload(), and the scan response
  * is updated using setAdvertisingScanResponse(). If the advertising is already
  * updated, the data will take effect from the next advertising event.
  *
  * To create a valid advertising payload and scan response, you may use
  * AdvertisingDataBuilder. You must first allocate memory and create an mbed::Span and
  * pass that into the AdvertisingDataBuilder, which will only be able to add as much
  * data as fits in the provided buffer. The builder accepts any size of the buffer,
  * but for the created data to be usable, it must be smaller than the maximum data
  * length returned from getMaxAdvertisingDataLength().
  *
  * Another option is to use AdvertisingDataSimpleBuilder, which allocates memory
  * on the stack and offers a fluent interface at the expense of a reduced set of
  * APIs and error management options.
  *
  * @note Prior to Bluetooth 5, advertising and scanning payload size were limited
  * to LEGACY_ADVERTISING_MAX_SIZE. It changed with Bluetooth 5, and now the maximum
  * size of data that can be advertised depends on the controller. If  you wish
  * to be compatible with older devices, you may wish to advertise with the
  * LEGACY_ADVERTISING_HANDLE. This uses payloads no larger than LEGACY_ADVERTISING_MAX_SIZE
  * with that advertising set.
  *
  * @par Extended advertising
  *
  * Extended advertising allows for a wider choice of options than legacy advertising.
  * You can send bigger payloads and use different PHYs. This allows for bigger throughput
  * or longer range.
  *
  * Extended advertising may be split across many packets and takes place on both the
  * regular advertising channels and the rest of the 37 channels normally used by
  * connected devices.
  *
  * The 3 channels used in legacy advertising are called primary advertisement channels.
  * The remaining 37 channels are used for secondary advertising. Unlike sending data
  * during a connection, this allows the device to broadcast data to multiple devices.
  *
  * The advertising starts on the primary channels (which you may select) and continues
  * on the secondary channels as indicated in the packet sent on the primary channel.
  * This way, the advertising can send large payloads without saturating the advertising
  * channels. Primary channels are limited to 1M and coded PHYs, but secondary channels
  * may use the increased throughput 2M PHY.
  *
  * @par Periodic advertising
  *
  * Similarly, you can use periodic advertising to transfer regular data to multiple
  * devices.
  *
  * The advertiser uses primary channels to advertise the information needed to
  * listen to the periodic advertisements on secondary channels. This sync information
  * will be used by the scanner who can now optimize for power consumption and only
  * listen for the periodic advertisements at specified times.
  *
  * Like extended advertising, periodic advertising offers extra PHY options of 2M
  * and coded. The payload may be updated at any time and will be updated on the next
  * advertisement event when the periodic advertising is active.
  *
  * @par Advertising sets
  *
  * Advertisers may advertise multiple payloads at the same time. The configuration
  * and identification of these is done through advertising sets. Use a handle
  * obtained from createAvertisingSet() for advertising operations. After ending
  * all advertising operations, remove the handle from the system using
  * destroyAdvertisingHandle().
  *
  * Extended advertising and periodic advertising is an optional feature, and not all
  * devices support it. Some will only be able to see the now-called legacy advertising.
  *
  * Legacy advertising is available through a special handle, LEGACY_ADVERTISING_HANDLE.
  * This handle is always available, doesn't need to be created and can't be
  * destroyed.
  *
  * There is a limited number of advertising sets available because they require support
  * from the controller. Their availability is dynamic and may be queried at any time
  * using getMaxAdvertisingSetNumber(). Advertising sets take up resources even if
  * they are not actively advertising right now, so it's important to destroy the set
  * when you're done with it (or reuse it in the next advertisement).
  *
  * Periodic advertising and extended advertising share the same set but not the same
  * data. Extended advertising carries out periodic advertising synchronization
  * information. Therefore, to let other devices be aware that your device
  * exposes periodic advertising, you should start extended advertising of the set.
  * Subsequently, you may disable extended advertising, and the periodic advertising
  * will continue. If you start periodic advertising while extended advertising is
  * inactive, periodic advertising won't start until you start extended advertising
  * at a later time.
  *
  * @par Privacy
  *
  * Privacy is a feature that allows a device to avoid being tracked by other
  * (untrusted) devices. The device achieves it by periodically generating a
  * new random address. The random address may be a resolvable random address,
  * enabling trusted devices to recognize it as belonging to the same
  * device. These trusted devices receive an Identity Resolution Key (IRK)
  * during pairing. This is handled by the SecurityManager and relies on the
  * other device accepting and storing the IRK.
  *
  * You need to enable privacy by calling enablePrivacy() after having
  * initialized the SecurityManager because privacy requires SecurityManager
  * to handle IRKs. The behavior of privacy enabled devices is set by
  * using setCentralPrivacyConfiguration(), which specifies what the device
  * should be with devices using random addresses. Random addresses
  * generated by privacy enabled devices can be of two types: resolvable
  * (by devices who have the IRK) and unresolvable. Unresolvable addresses
  * can't be used for connecting and connectable advertising. Therefore, a
  * resolvable one will be used for these regardless of the privacy
  * configuration.
  *
  * @par Scanning
  *
  * Scanning consists of listening for peer advertising packets. From a scan, a
  * device can identify devices available in its environment.
  *
  * If the device scans actively, then it will send scan request to scannable
  * advertisers and collect their scan responses.
  *
  * Scanning is done by creating ScanParameters and applying them with
  * setScanParameters(). One configured, you may call startScan().
  *
  * When a scanning device receives an advertising packet, it will call
  * onAdvertisingReport() in the registered event handler. A whitelist may be used
  * to limit the advertising reports by setting the correct policy in the scan
  * parameters.
  *
  * @par Connection event handling
  *
  * A peer may connect device advertising connectable packets. The advertising
  * procedure ends as soon as the device is connected. If an advertising timeout
  * has been set in the advertising parameters then onAdvertisingEnd will be called
  * in the registered eventHandler when it runs out.
  *
  * A device accepting a connection request from a peer is named a peripheral,
  * and the device initiating the connection is named a central.
  *
  * Connection is initiated by central devices. A call to connect() will result in
  * the device scanning on any PHYs set in ConectionParamters passed in.
  *
  * Peripheral and central receive a connection event when the connection is
  * effective. If successful will result in a call to onConnectionComplete in the
  * EventHandler registered with the Gap.
  *
  * It the connection attempt fails it will result in onConnectionComplete called
  * on the central device with the event carrying the error flag.
  *
  * @par Changing the PHYsical transport of a connection
  *
  * Once a connection has been established, it is possible to change the physical
  * transport used between the local and the distant device. Changing the transport
  * can either increase the bandwidth or increase the communication range.
  * An increased bandwidth equals a better power consumption but also a loss in
  * sensibility and therefore a degraded range.
  *
  * Symmetrically an increased range means a lowered bandwidth and a degraded power
  * consumption.
  *
  * Applications can change the PHY used by calling the function setPhy. Once the
  * update has been made the result is forwarded to the application by calling the
  * function onPhyUpdateComplete of the event handler registered.
  *
  * @par disconnection
  *
  * The application code initiates a disconnection when it calls the
  * disconnect(Handle_t, DisconnectionReason_t) function.
  *
  * Disconnection may also be initiated by the remote peer or the local
  * controller/stack. To catch all disconnection events, application code may
  * set up an handler taking care of disconnection events by calling
  * onDisconnection().
  *
  * @par Modulation Schemes
  *
  * When supported by the host and controller you can select different modulation
  * schemes (@see BLUETOOTH SPECIFICATION Version 5.0 | Vol 1, Part A - 1.2):
  * - LE 1M PHY
  * - LE 2M PHY
  * - LE coded PHY
  *
  * You may set preferred PHYs (separately for RX and TX) using setPreferredPhys().
  * You may also set the currently used PHYs on a selected connection using setPhy().
  * Both of these settings are only advisory and the controller is allowed to make
  * its own decision on the best PHY to use based on your request, the peer's
  * supported features and the connection's physical conditions.
  *
  * You may query the currently used PHY using readPhy() which will return the
  * result through a call to the registered event handler. You may register the
  * handler with setEventHandler(). The events inform about the currently used
  * PHY and of any changes to PHYs which may be triggered autonomously by the
  * controller or by the peer.
  */
 class Gap {
 public:
     /**
      * Gap shutdown event handler.
      *
      * @see Gap::onShutdown().
      */
     typedef FunctionPointerWithContext<const Gap *> GapShutdownCallback_t;
 
     /**
      * Callchain of gap shutdown event handler.
      *
      * @see Gap::onShutdown().
      */
     typedef CallChainOfFunctionPointersWithContext<const Gap *>
         GapShutdownCallbackChain_t;
 
 public:
     /**
      * Definition of the general handler of Gap related events.
      */
     struct EventHandler {
         /**
          * Called when an advertising device receive a scan response.
          *
          * @param event Scan request event.
          *
          * @version: 5+.
          *
          * @see AdvertisingParameters::setScanRequestNotification().
          */
         virtual void onScanRequestReceived(const ScanRequestEvent &event)
         {
         }
 
         /**
          * Called when advertising starts.
          *
          * @param event Advertising start event.
          *
          * @see startAdvertising()
          */
         virtual void onAdvertisingStart(const AdvertisingStartEvent &event)
         {
         }
 
         /**
          * Called when advertising ends.
          *
          * Advertising ends when the process timeout or if it is stopped by the
          * application or if the local device accepts a connection request.
          *
          * @param event Advertising end event.
          *
          * @see startAdvertising()
          * @see stopAdvertising()
          * @see onConnectionComplete()
          */
         virtual void onAdvertisingEnd(const AdvertisingEndEvent &event)
         {
         }
 
         /**
          * Called when a scanner receives an advertising or a scan response packet.
          *
          * @param event Advertising report.
          *
          * @see startScan()
          */
         virtual void onAdvertisingReport(const AdvertisingReportEvent &event)
         {
         }
 
         /**
          * Called when scan times out.
          *
          * @param event Associated event.
          *
          * @see startScan()
          */
         virtual void onScanTimeout(const ScanTimeoutEvent &event)
         {
         }
 
         /**
          * Called when first advertising packet in periodic advertising is received.
          *
          * @param event Periodic advertising sync event.
          *
          * @version: 5+.
          *
          * @see createSync()
          */
         virtual void onPeriodicAdvertisingSyncEstablished(
             const PeriodicAdvertisingSyncEstablishedEvent &event
         )
         {
         }
 
         /**
          * Called when a periodic advertising packet is received.
          *
          * @param event Periodic advertisement event.
          *
          * @version: 5+.
          *
          * @see createSync()
          */
         virtual void onPeriodicAdvertisingReport(
             const PeriodicAdvertisingReportEvent &event
         )
         {
         }
 
         /**
          * Called when a periodic advertising sync has been lost.
          *
          * @param event Details of the event.
          *
          * @version: 5+.
          *
          * @see createSync()
          */
         virtual void onPeriodicAdvertisingSyncLoss(
             const PeriodicAdvertisingSyncLoss &event
         )
         {
         }
 
         /**
          * Called when connection attempt ends or an advertising device has been
          * connected.
          *
          * @see startAdvertising()
          * @see connect()
          *
          * @param event Connection event.
          */
         virtual void onConnectionComplete(const ConnectionCompleteEvent &event)
         {
         }
 
         /**
          * Called when the peer request connection parameters updates.
          *
          * Application must accept the update with acceptConnectionParametersUpdate()
          * or reject it with rejectConnectionParametersUpdate().
          *
          * @param event The connection parameters requested by the peer.
          *
          * @version 4.1+.
          *
          * @note This event is not generated if connection parameters update
          * is managed by the middleware.
          *
          * @see manageConnectionParametersUpdateRequest()
          * @see acceptConnectionParametersUpdate()
          * @see rejectConnectionParametersUpdate()
          */
         virtual void onUpdateConnectionParametersRequest(
             const UpdateConnectionParametersRequestEvent &event
         )
         {
         }
 
         /**
          * Called when connection parameters have been updated.
          *
          * @param event The new connection parameters.
          *
          * @see updateConnectionParameters()
          * @see acceptConnectionParametersUpdate()
          */
         virtual void onConnectionParametersUpdateComplete(
             const ConnectionParametersUpdateCompleteEvent &event
         )
         {
         }
 
         /**
          * Called when a connection has been disconnected.
          *
          * @param event Details of the event.
          *
          * @see disconnect()
          */
         virtual void onDisconnectionComplete(const DisconnectionCompleteEvent &event)
         {
         }
 
         /**
          * Function invoked when the current transmitter and receiver PHY have
          * been read for a given connection.
          *
          * @param status Status of the operation: BLE_ERROR_NONE in case of
          * success or an appropriate error code.
          *
          * @param connectionHandle: The handle of the connection for which the
          * PHYs have been read.
          *
          * @param txPhy PHY used by the transmitter.
          *
          * @param rxPhy PHY used by the receiver.
          *
          * @see readPhy().
          *
          * @version: 5+.
          */
         virtual void onReadPhy(
             ble_error_t status,
             connection_handle_t connectionHandle,
             phy_t txPhy,
             phy_t rxPhy
         )
         {
         }
 
         /**
          * Function invoked when the update process of the PHY has been completed.
          *
          * The process can be initiated by a call to the function setPhy, the
          * local bluetooth subsystem or the peer.
          *
          * @param status Status of the operation: BLE_ERROR_NONE in case of
          * success or an appropriate error code.
          *
          * @param connectionHandle: The handle of the connection on which the
          * operation was made.
          *
          * @param txPhy PHY used by the transmitter.
          *
          * @param rxPhy PHY used by the receiver.
          *
          * @note Success doesn't mean the PHY has been updated it means both
          * ends have negotiated the best PHY according to their configuration and
          * capabilities. The PHY currently used are present in the txPhy and
          * rxPhy parameters.
          *
          * @see setPhy()
          *
          * @version: 5+.
          */
         virtual void onPhyUpdateComplete(
             ble_error_t status,
             connection_handle_t connectionHandle,
             phy_t txPhy,
             phy_t rxPhy
         )
         {
         }
 
         /**
          * Function invoked when the connections changes the maximum number of octets
          * that can be sent or received by the controller in a single packet. A single
          * L2CAP packet can be fragmented across many such packets.
          *
          * @note This only triggers if controller supports data length extension and
          * negotiated data length is longer than the default 23.
          *
          * @param connectionHandle The handle of the connection that changed the size.
          * @param txSize Number of octets we can send on this connection in a single packet.
          * @param rxSize Number of octets we can receive on this connection in a single packet.
          */
         virtual void onDataLengthChange(
             connection_handle_t connectionHandle,
             uint16_t txSize,
             uint16_t rxSize
         )
         {
         }
 
         /**
          * Function invoked when the privacy subsystem has been enabled and is
          * ready to be used.
          */
         virtual void onPrivacyEnabled()
         {
         }
     protected:
         /**
          * Prevent polymorphic deletion and avoid unnecessary virtual destructor
          * as the Gap class will never delete the instance it contains.
          */
         ~EventHandler() = default;
     };
 
     /**
      * Preferred connection parameter display in Generic Access Service.
      */
     typedef struct {
         /**
          * Minimum interval between two connection events allowed for a
          * connection.
          *
          * It shall be less than or equal to maxConnectionInterval. This value,
          * in units of 1.25ms, is included in the range [0x0006 : 0x0C80].
          */
         uint16_t minConnectionInterval;
 
         /**
          * Maximum interval between two connection events allowed for a
          * connection.
          *
          * It shall be greater than or equal to minConnectionInterval. This
          * value is in unit of 1.25ms and is in the range [0x0006 : 0x0C80].
          */
         uint16_t maxConnectionInterval;
 
         /**
          * Number of connection events the slave can drop if it has nothing to
          * communicate to the master.
          *
          * This value shall be in the range [0x0000 : 0x01F3].
          */
         uint16_t slaveLatency;
 
         /**
          * Link supervision timeout for the connection.
          *
          * Time after which the connection is considered lost if the device
          * didn't receive a packet from its peer.
          *
          * It is larger than:
          *        (1 + slaveLatency) * maxConnectionInterval * 2
          *
          * This value is in the range [0x000A : 0x0C80] and is in unit of
          * 10 ms.
          *
          * @note maxConnectionInterval is in ms in the formulae above.
          */
         uint16_t connectionSupervisionTimeout;
     } PreferredConnectionParams_t;
 
     /**
      * Assign the event handler implementation that will be used by the gap
      * module to signal events back to the application.
      *
      * @param handler Application implementation of an EventHandler.
      *
      * @note Multiple discrete EventHandler instances may be used by adding them
      * to a ChainableGapEventHandler and then setting the chain as the primary
      * Gap EventHandler using this function.
      *
      * @see ChainableGapEventHandler
      */
     void setEventHandler(EventHandler *handler);
 
     /** Check controller support for a specific feature.
      *
      * @param feature Feature to check.
      * @return True if feature is supported.
      */
     bool isFeatureSupported(controller_supported_features_t feature);
 
     /*                                     advertising                                           */
 #if BLE_ROLE_BROADCASTER
     /** Return currently available number of supported advertising sets.
      *  This may change at runtime.
      *
      * @note Devices that do not support Bluetooth 5 still offers one advertising
      * set that has the handle LEGACY_ADVERTISING_HANDLE.
      *
      * @return Number of advertising sets that may be created at the same time.
      */
     uint8_t getMaxAdvertisingSetNumber();
 
     /** Return maximum advertising data length supported.
      *
      * @return Maximum advertising data length supported.
      */
     uint16_t getMaxAdvertisingDataLength();
 
     /** Return maximum advertising data length supported for connectable advertising.
      *
      * @return Maximum advertising data length supported for connectable advertising.
      */
     uint16_t getMaxConnectableAdvertisingDataLength();
 
     /** Return maximum advertising data length you may set if advertising set is active.
      *
      * @return Maximum advertising data length you may set if advertising set is active.
      */
     uint16_t getMaxActiveSetAdvertisingDataLength();
 
 #if BLE_FEATURE_EXTENDED_ADVERTISING
     /** Create an advertising set and apply the passed in parameters. The handle returned
      *  by this function must be used for all other calls that accept an advertising handle.
      *  When done with advertising, remove from the system using destroyAdvertisingSet().
      *
      * @note The exception is the LEGACY_ADVERTISING_HANDLE which may be used at any time.
      *
      * @param[out] handle Advertising handle returned, valid only if function returned success.
      * @param parameters Advertising parameters for the newly created set.
      * @return BLE_ERROR_NONE on success.
      *
      * @version 5+
      */
     ble_error_t createAdvertisingSet(
         advertising_handle_t *handle,
         const AdvertisingParameters &parameters
     );
 
     /** Remove the advertising set (resets its set parameters). The advertising set must not
      *  be active.
      *
      * @note LEGACY_ADVERTISING_HANDLE may not be destroyed.
      *
      * @param handle Advertising set handle.
      * @return BLE_ERROR_NONE on success.
      *
      * @version 5+
      */
     ble_error_t destroyAdvertisingSet(advertising_handle_t handle);
 #endif // BLE_FEATURE_EXTENDED_ADVERTISING
 
     /** Set advertising parameters of an existing set.
      *
      * @param handle Advertising set handle.
      * @param params New advertising parameters.
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t setAdvertisingParameters(
         advertising_handle_t handle,
         const AdvertisingParameters &params
     );
 
     /** Set new advertising payload for a given advertising set.
      *
      * @param handle Advertising set handle.
      * @param payload Advertising payload.
      *
      * @note If advertising set is active you may only set payload of length equal or less
      * than getMaxActiveSetAdvertisingDataLength(). If you require a longer payload you must
      * stop the advertising set, set the payload and restart the set.
      *
      * @return BLE_ERROR_NONE on success.
      *
      * @see ble::AdvertisingDataBuilder to build a payload.
      */
     ble_error_t setAdvertisingPayload(
         advertising_handle_t handle,
         mbed::Span<const uint8_t> payload
     );
 
     /** Set new advertising scan response for a given advertising set. This will be sent to
      *  device who perform active scanning.
      *
      * @param handle Advertising set handle.
      * @param response Advertising scan response.
      *
      * @note If advertising set is active you may only set payload of length equal or less
      * than getMaxActiveSetAdvertisingDataLength(). If you require a longer payload you must
      * stop the advertising set, set the payload and restart the set.
      *
      * @return BLE_ERROR_NONE on success.
      *
      * @see ble::AdvertisingDataBuilder to build a payload.
      */
     ble_error_t setAdvertisingScanResponse(
         advertising_handle_t handle,
         mbed::Span<const uint8_t> response
     );
 
     /** Start advertising using the given advertising set.
      *
      * @param handle Advertising set handle.
      * @param maxDuration Max duration for advertising (in units of 10ms) - 0 means no limit.
      * @param maxEvents Max number of events produced during advertising - 0 means no limit.
      * @return BLE_ERROR_NONE on success.
      *
      * @see EventHandler::onAdvertisingStart when the advertising starts.
      * @see EventHandler::onScanRequestReceived when a scan request is received.
      * @see EventHandler::onAdvertisingEnd when the advertising ends.
      * @see EventHandler::onConnectionComplete when the device gets connected
      * by a peer.
      */
     ble_error_t startAdvertising(
         advertising_handle_t handle,
         adv_duration_t maxDuration = adv_duration_t::forever(),
         uint8_t maxEvents = 0
     );
 
     /** Stop advertising given advertising set. This is separate from periodic advertising
      *  which will not be affected.
      *
      * @param handle Advertising set handle.
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t stopAdvertising(advertising_handle_t handle);
 
     /** Check if advertising is active for a given advertising set.
      *
      * @param handle Advertising set handle.
      * @return True if advertising is active on this set.
      */
     bool isAdvertisingActive(advertising_handle_t handle);
 #endif // BLE_ROLE_BROADCASTER
 
 #if BLE_ROLE_BROADCASTER
 #if BLE_FEATURE_PERIODIC_ADVERTISING
     /** Set periodic advertising parameters for a given advertising set.
      *
      * @param handle Advertising set handle.
      * @param periodicAdvertisingIntervalMin Minimum interval for periodic advertising.
      * @param periodicAdvertisingIntervalMax Maximum interval for periodic advertising.
      * @param advertiseTxPower Include transmission power in the advertisements.
      * @return BLE_ERROR_NONE on success.
      *
      * @version 5+
      */
     ble_error_t setPeriodicAdvertisingParameters(
         advertising_handle_t handle,
         periodic_interval_t periodicAdvertisingIntervalMin,
         periodic_interval_t periodicAdvertisingIntervalMax,
         bool advertiseTxPower = true
     );
 
     /** Set new periodic advertising payload for a given advertising set.
      *
      * @param handle Advertising set handle.
      * @param payload Advertising payload.
      * @return BLE_ERROR_NONE on success.
      *
      * @note If advertising set is active you may only set payload of length equal or less
      * than getMaxActiveSetAdvertisingDataLength(). If you require a longer payload you must
      * stop the advertising set, set the payload and restart the set. Stopping the set will
      * cause peers to lose sync on the periodic set.
      *
      * @see ble::AdvertisingDataBuilder to build a payload.
      *
      * @version 5+
      */
     ble_error_t setPeriodicAdvertisingPayload(
         advertising_handle_t handle,
         mbed::Span<const uint8_t> payload
     );
 
     /** Start periodic advertising for a given set. Periodic advertising will not start until
      *  normal advertising is running but will continue to run after normal advertising has stopped.
      *
      * @param handle Advertising set handle.
      * @return BLE_ERROR_NONE on success.
      *
      * @version 5+
      */
     ble_error_t startPeriodicAdvertising(advertising_handle_t handle);
 
     /** Stop periodic advertising for a given set.
      *
      * @param handle Advertising set handle.
      * @return BLE_ERROR_NONE on success.
      *
      * @version 5+
      */
     ble_error_t stopPeriodicAdvertising(advertising_handle_t handle);
 
     /** Check if periodic advertising is active for a given advertising set.
      *
      * @param handle Advertising set handle.
      * @return True if periodic advertising is active on this set.
      *
      * @version 5+
      */
     bool isPeriodicAdvertisingActive(advertising_handle_t handle);
 #endif // BLE_ROLE_BROADCASTER
 #endif // BLE_FEATURE_PERIODIC_ADVERTISING
 
     /*                                     scanning                                              */
 #if BLE_ROLE_OBSERVER
     /** Set new scan parameters.
      *
      * @param params Scan parameters, @see GapScanParameters for details.
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t setScanParameters(const ScanParameters &params);
 
     /** Start scanning.
      *
      * @param duration How long to scan for. Special value 0 means scan forever.
      * @param filtering Filtering policy.
      * @param period How long to scan for in single period. If the period is 0 and duration
      *               is nonzero the scan will last for single duration.
      *
      * @note When the duration and period parameters are non-zero scanning will last for
      * the duration within the period. After the scan period has expired a new scan period
      * will begin and scanning. This will repeat until stopScan() is called.
      *
      * @return BLE_ERROR_NONE on success.
      *
      * @see EventHandler::onAdvertisingReport to collect advertising reports.
      * @see EventHandler::onScanTimeout when scanning timeout.
      */
     ble_error_t startScan(
         scan_duration_t duration = scan_duration_t::forever(),
         duplicates_filter_t filtering = duplicates_filter_t::DISABLE,
         scan_period_t period = scan_period_t(0)
     );
 
     /**
      * Stop the ongoing scanning procedure.
      *
      * The current scanning parameters remain in effect.
      *
      * @retval BLE_ERROR_NONE if successfully stopped scanning procedure.
      */
     ble_error_t stopScan();
 #endif // BLE_ROLE_OBSERVER
 
 #if BLE_ROLE_OBSERVER
 #if BLE_FEATURE_PERIODIC_ADVERTISING
     /** Synchronize with periodic advertising from an advertiser and begin receiving periodic
      *  advertising packets.
      *
      * @param peerAddressType Peer address type.
      * @param peerAddress Peer address.
      * @param sid Advertiser set identifier.
      * @param maxPacketSkip Number of consecutive periodic advertising packets that the receiver
      *                      may skip after successfully receiving a periodic advertising packet.
      * @param timeout Maximum permitted time between successful receptions. If this time is
      *                exceeded, synchronisation is lost.
      * @return BLE_ERROR_NONE on success.
      *
      * @see EventHandler::onPeriodicAdvertisingSyncEstablished when the sync is
      * effective.
      * @see EventHandler::onPeriodicAdvertisingReport when data are issued by the
      * peer.
      * @see EventHandler::onPeriodicAdvertisingSyncLoss when the sync has been
      * loss.
      *
      * @version 5+
      */
     ble_error_t createSync(
         peer_address_type_t peerAddressType,
         const address_t &peerAddress,
         uint8_t sid,
         slave_latency_t maxPacketSkip,
         sync_timeout_t timeout
     );
 
     /** Synchronize with periodic advertising from an advertiser and begin receiving periodic
      *  advertising packets. Use periodic advertising sync list to determine who to sync with.
      *
      * @param maxPacketSkip Number of consecutive periodic advertising packets that the receiver
      *                      may skip after successfully receiving a periodic advertising packet.
      * @param timeout Maximum permitted time between successful receives.
      *                If this time is exceeded, synchronisation is lost.
      * @return BLE_ERROR_NONE on success.
      *
      * @see EventHandler::onPeriodicAdvertisingSyncEstablished when the sync is
      * effective.
      * @see EventHandler::onPeriodicAdvertisingReport when data are issued by the
      * peer.
      * @see EventHandler::onPeriodicAdvertisingSyncLoss when the sync has been
      * loss.
      *
      * @version 5+
      */
     ble_error_t createSync(
         slave_latency_t maxPacketSkip,
         sync_timeout_t timeout
     );
 
     /** Cancel sync attempt.
      *
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t cancelCreateSync();
 
     /** Stop reception of the periodic advertising identified by the handle.
      *
      * @param handle Periodic advertising synchronisation handle.
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t terminateSync(periodic_sync_handle_t handle);
 
     /** Add device to the periodic advertiser list. Cannot be called when sync is ongoing.
      *
      * @param peerAddressType Peer address type.
      * @param peerAddress Peer address.
      * @param sid Advertiser set identifier.
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t addDeviceToPeriodicAdvertiserList(
         peer_address_type_t peerAddressType,
         const address_t &peerAddress,
         advertising_sid_t sid
     );
 
     /** Remove device from the periodic advertiser list. Cannot be called when sync is ongoing.
      *
      * @param peerAddressType Peer address type.
      * @param peerAddress Peer address.
      * @param sid Advertiser set identifier.
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t removeDeviceFromPeriodicAdvertiserList(
         peer_address_type_t peerAddressType,
         const address_t &peerAddress,
         advertising_sid_t sid
     );
 
     /** Remove all devices from periodic advertiser list.
      *
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t clearPeriodicAdvertiserList();
 
     /** Get number of devices that can be added to the periodic advertiser list.
      * @return Number of devices that can be added to the periodic advertiser list.
      */
     uint8_t getMaxPeriodicAdvertiserListSize();
 #endif // BLE_ROLE_OBSERVER
 #endif // BLE_FEATURE_PERIODIC_ADVERTISING
 
 #if BLE_ROLE_CENTRAL
     /**
      * Initiate a connection to a peer.
      *
      * Once the connection is established an onConnectionComplete in the event handler
      * will be called.
      *
      * @param peerAddressType
      * @param peerAddress
      * @param connectionParams
      *
      * @return BLE_ERROR_NONE if connection establishment procedure is started
      * successfully. The connectionCallChain (if set) is invoked upon
      * a connection event.
      *
      * @see EventHandler::onConnectionComplete will be called whether the
      * connection process succeed or fail.
      * @see EventHandler::onDisconnectionComplete is called when the connection
      * ends.
      */
     ble_error_t connect(
         peer_address_type_t peerAddressType,
         const address_t &peerAddress,
         const ConnectionParameters &connectionParams
     );
 
     /** Cancel the connection attempt. This is not guaranteed to succeed. As a result
      *  onConnectionComplete in the event handler will be called. Check the success parameter
      *  to see if the connection was created.
      *
      * @return BLE_ERROR_NONE if the connection attempt has been requested to be cancelled.
      * Returns BLE_ERROR_OPERATION_NOT_PERMITTED if no ongoing connection for last used address found.
      */
     ble_error_t cancelConnect();
 #endif // BLE_ROLE_CENTRAL
 
 #if BLE_FEATURE_CONNECTABLE
     /**
      * Update connection parameters of an existing connection.
      *
      * In the central role, this initiates a Link Layer connection parameter
      * update procedure. In the peripheral role, this sends the corresponding
      * L2CAP request and waits for the central to accept or reject the requested
      * connection parameters.
      *
      * @param connectionHandle The handle of the connection to update.
      * @param minConnectionInterval The minimum connection interval requested.
      * @param maxConnectionInterval The maximum connection interval requested.
      * @param slaveLatency The slave latency requested.
      * @param supervision_timeout The supervision timeout requested.
      * @param minConnectionEventLength The minimum connection event length requested.
      * @param maxConnectionEventLength The maximum connection event length requested.
      *
      * @return BLE_ERROR_NONE if the request has been sent and false otherwise.
      *
      * @see EventHandler::onUpdateConnectionParametersRequest when a central
      * receives a request to update the connection parameters.
      * @see EventHandler::onConnectionParametersUpdateComplete when connection
      * parameters have been updated.
      *
      * @version 4.0+ for central
      * @version 4.1+ for peripheral
      */
     ble_error_t updateConnectionParameters(
         connection_handle_t connectionHandle,
         conn_interval_t minConnectionInterval,
         conn_interval_t maxConnectionInterval,
         slave_latency_t slaveLatency,
         supervision_timeout_t supervision_timeout,
         conn_event_length_t minConnectionEventLength = conn_event_length_t(0),
         conn_event_length_t maxConnectionEventLength = conn_event_length_t(0)
     );
 
     /**
      * Allows the application to accept or reject a connection parameters update
      * request.
      *
      * If this process is managed by the middleware; new connection parameters
      * from a slave are always accepted.
      *
      * @param userManageConnectionUpdateRequest true to let the application
      * manage the process and false to let the middleware manage it.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      *
      * @version 4.1+
      *
      * @see EventHandler::onUpdateConnectionParametersRequest when a central
      * receives a request to update the connection parameters.
      *
      * @see acceptConnectionParametersUpdate to accept the request.
      * @see rejectConnectionParametersUpdate to reject the request.
      */
     ble_error_t manageConnectionParametersUpdateRequest(
         bool userManageConnectionUpdateRequest
     );
 
     /**
      * Accept update of the connection parameters.
      *
      * The central can adjust the new connection parameters.
      *
      * @param connectionHandle The handle of the connection that has initiated
      * the request.
      * @param minConnectionInterval The minimum connection interval to be applied.
      * @param maxConnectionInterval The maximum connection interval to be applied.
      * @param slaveLatency The slave latency to be applied.
      * @param supervision_timeout The supervision timeout to be applied.
      * @param minConnectionEventLength The minimum connection event length to be
      * applied.
      * @param maxConnectionEventLength The maximum connection event length to be
      * applied.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      *
      * @version 4.1+
      *
      * @see manageConnectionParametersUpdateRequest To let the application
      * manage the process.
      *
      * @see EventHandler::onUpdateConnectionParametersRequest Called when a
      * request to update the connection parameters is received.
      *
      * @see EventHandler::onConnectionParametersUpdateComplete Called when the
      * new connection parameters are effective.
      */
     ble_error_t acceptConnectionParametersUpdate(
         connection_handle_t connectionHandle,
         conn_interval_t minConnectionInterval,
         conn_interval_t maxConnectionInterval,
         slave_latency_t slaveLatency,
         supervision_timeout_t supervision_timeout,
         conn_event_length_t minConnectionEventLength = conn_event_length_t(0),
         conn_event_length_t maxConnectionEventLength = conn_event_length_t(0)
     );
 
     /**
      * Reject a request to change the connection parameters.
      *
      * @param connectionHandle The handle of the connection that has initiated
      * the request.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      *
      * @version 4.1+
      *
      * @see manageConnectionParametersUpdateRequest To let the application
      * manage the process.
      *
      * @see EventHandler::onUpdateConnectionParametersRequest Called when a
      * request to update the connection parameters is received.
      */
     ble_error_t rejectConnectionParametersUpdate(
         connection_handle_t connectionHandle
     );
 
     /**
      * Initiate a disconnection procedure.
      *
      * Once the disconnection procedure has completed a
      * DisconnectionCallbackParams_t, the event is emitted to handlers that
      * have been registered with onDisconnection().
      *
      * @param[in] reason Reason of the disconnection transmitted to the peer.
      * @param[in] connectionHandle Handle of the connection to end.
      *
      * @return  BLE_ERROR_NONE if the disconnection procedure successfully
      * started.
      *
      * @see EventHandler::onDisconnectionComplete when the disconnection is
      * effective.
      */
     ble_error_t disconnect(
         connection_handle_t connectionHandle,
         local_disconnection_reason_t reason
     );
 #endif // BLE_FEATURE_CONNECTABLE
 #if BLE_FEATURE_PHY_MANAGEMENT
     /**
      * Read the PHY used by the transmitter and the receiver on a connection.
      *
      * Once the PHY has been read, it is reported back via the function onPhyRead
      * of the event handler registered by the application.
      *
      * @param connection Handle of the connection for which the PHY being used is
      * queried.
      *
      * @return BLE_ERROR_NONE if the read PHY procedure has been started or an
      * appropriate error code.
      *
      * @version 5+
      *
      * @see EventHandler::onReadPhy is called when the phy has been read.
      */
     ble_error_t readPhy(connection_handle_t connection);
 
     /**
      * Set the preferred PHYs to use in a connection.
      *
      * @param txPhys: Set of PHYs preferred for tx operations. If NULL then no
      * preferred PHYs are set and the default value of the subsystem is used.
      *
      * @param rxPhys: Set of PHYs preferred for rx operations. If NULL then no
      * preferred PHYs are set and the default value of the subsystem is used.
      *
      * @return BLE_ERROR_NONE if the preferences have been set or an appropriate
      * error code.
      *
      * @version 5+
      */
     ble_error_t setPreferredPhys(
         const phy_set_t *txPhys,
         const phy_set_t *rxPhys
     );
 
     /**
      * Update the PHY used by a connection.
      *
      * Once the update process has been completed, it is reported back to the
      * application via the function onPhyUpdateComplete of the event handler
      * registered by the application.
      *
      * @param connection Handle of the connection to update.
      *
      * @param txPhys Set of PHYs preferred for tx operations. If NULL then the
      * choice is up to the Bluetooth subsystem.
      *
      * @param rxPhys Set of PHYs preferred for rx operations. If NULL then the
      * choice is up to the Bluetooth subsystem.
      *
      * @param codedSymbol Number of symbols used to code a bit when le coded is
      * used. If the value is UNDEFINED then the choice is up to the Bluetooth
      * subsystem.
      *
      * @return BLE_ERROR_NONE if the update PHY procedure has been successfully
      * started or an error code.
      *
      * @see EventHandler::onPhyUpdateComplete is called when the phy used by the
      * connection has been updated.
      */
     ble_error_t setPhy(
         connection_handle_t connection,
         const phy_set_t *txPhys,
         const phy_set_t *rxPhys,
         coded_symbol_per_bit_t codedSymbol
     );
 #endif // BLE_FEATURE_PHY_MANAGEMENT
 
 #if BLE_FEATURE_PRIVACY
     /**
      * Enable or disable privacy mode of the local device.
      *
      * When privacy is enabled, the system use private addresses while it scans,
      * advertises or initiate a connection. The device private address is
      * renewed every 15 minutes.
      *
      * @par Configuration
      *
      * The privacy feature can be configured with the help of the functions
      * setPeripheralPrivacyConfiguration and setCentralPrivacyConfiguration
      * which respectively set the privacy configuration of the peripheral and
      * central role.
      *
      * @par Default configuration of peripheral role
      *
      * By default private resolvable addresses are used for all procedures;
      * including advertisement of nonconnectable packets. Connection request
      * from an unknown initiator with a private resolvable address triggers the
      * pairing procedure.
      *
      * @par Default configuration of central role
      *
      * By default private resolvable addresses are used for all procedures;
      * including active scanning. Addresses present in advertisement packet are
      * resolved and advertisement packets are forwarded to the application
      * even if the advertiser private address is unknown.
      *
      * @par Initialization of the privacy subsystem
      *
      * When privacy is enabled, the system generates new resolvable and non
      * resolvable private addresses. Scan, Advertising and Connecting to a peer
      * won't be available until the generation process completes. When addresses
      * have been generated, the application is notified that privacy
      * initialisation as completed with a call to EventHandler::onPrivacyEnabled .
      *
      * @param[in] enable Should be set to true to enable the privacy mode and
      * false to disable it.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      */
     ble_error_t enablePrivacy(bool enable);
 
 #if BLE_ROLE_BROADCASTER
     /**
      * Set the privacy configuration used by the peripheral role.
      *
      * @param[in] configuration The configuration to set.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      */
     ble_error_t setPeripheralPrivacyConfiguration(
         const peripheral_privacy_configuration_t *configuration
     );
 
     /**
      * Get the privacy configuration used by the peripheral role.
      *
      * @param[out] configuration The variable filled with the current
      * configuration.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      */
     ble_error_t getPeripheralPrivacyConfiguration(
         peripheral_privacy_configuration_t *configuration
     );
 #endif // BLE_ROLE_BROADCASTER
 
 #if BLE_ROLE_OBSERVER
     /**
      * Set the privacy configuration used by the central role.
      *
      * @param[in] configuration The configuration to set.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      */
     ble_error_t setCentralPrivacyConfiguration(
         const central_privacy_configuration_t *configuration
     );
 
     /**
      * Get the privacy configuration used by the central role.
      *
      * @param[out] configuration The variable filled with the current
      * configuration.
      *
      * @return BLE_ERROR_NONE in case of success or an appropriate error code.
      */
     ble_error_t getCentralPrivacyConfiguration(
         central_privacy_configuration_t *configuration
     );
 #endif // BLE_ROLE_OBSERVER
 #endif // BLE_FEATURE_PRIVACY
 
 #if BLE_FEATURE_WHITELIST
     /**
      * Get the maximum size of the whitelist.
      *
      * @return Maximum size of the whitelist.
      */
     uint8_t getMaxWhitelistSize() const;
 
     /**
      * Get the Link Layer to use the internal whitelist when scanning,
      * advertising or initiating a connection depending on the filter policies.
      *
      * @param[in,out] whitelist Define the whitelist instance which is used
      * to store the whitelist requested. In input, the caller provisions memory.
      *
      * @return BLE_ERROR_NONE if the implementation's whitelist was successfully
      * copied into the supplied reference.
      */
     ble_error_t getWhitelist(whitelist_t &whitelist) const;
 
     /**
      * Set the value of the whitelist to be used during GAP procedures.
      *
      * @param[in] whitelist A reference to a whitelist containing the addresses
      * to be copied to the internal whitelist.
      *
      * @return BLE_ERROR_NONE if the implementation's whitelist was successfully
      * populated with the addresses in the given whitelist.
      *
      * @note The whitelist must not contain non-resolvable addresses. This
      * results in a @ref BLE_ERROR_INVALID_PARAM because the remote peer might
      * change its private address at any time, and it is not possible to resolve
      * it.
      *
      * @note If the input whitelist is larger than @ref getMaxWhitelistSize(),
      * then @ref BLE_ERROR_PARAM_OUT_OF_RANGE is returned.
      */
     ble_error_t setWhitelist(const whitelist_t &whitelist);
 
 #endif // BLE_FEATURE_WHITELIST
 
     /**
      * Fetch the current address and its type.
      *
      * @param[out] typeP Type of the current address set.
      * @param[out] address Value of the current address.
      *
      * @note If privacy is enabled the device address may be unavailable to
      * application code.
      *
      * @return BLE_ERROR_NONE on success.
      */
     ble_error_t getAddress(
         own_address_type_t &typeP,
         address_t &address
     );
 
     /**
      * Return the type of a random address.
      *
      * @param[in] address The random address to retrieve the type from. The
      * address must be ordered in little endian.
      *
      * @param[out] addressType Type of the address to fill.
      *
      * @return BLE_ERROR_NONE in case of success or BLE_ERROR_INVALID_PARAM if
      * the address in input was not identifiable as a random address.
      */
     static ble_error_t getRandomAddressType(
         ble::address_t address,
         ble::random_address_type_t *addressType
     );
 
     /**
      * Reset the Gap instance.
      *
      * Reset process starts by notifying all registered shutdown event handlers
      * that the Gap instance is about to be shut down. Then, it clears all Gap state
      * of the associated object and then cleans the state present in the vendor
      * implementation.
      *
      * This function is meant to be overridden in the platform-specific
      * subclass. Nevertheless, the subclass only resets its
      * state and not the data held in Gap members. This is achieved by a
      * call to Gap::reset() from the subclass' reset() implementation.
      *
      * @return BLE_ERROR_NONE on success.
      *
      * @note Currently, a call to reset() does not reset the advertising and
      * scan parameters to default values.
      */
     ble_error_t reset();
 
         /**
      * Register a Gap shutdown event handler.
      *
      * The handler is called when the Gap instance is about to shut down.
      * It is usually issued after a call to BLE::shutdown().
      *
      * @param[in] callback Shutdown event handler to register.
      *
      * @note To unregister a shutdown event handler, use
      * onShutdown().detach(callback).
      */
     void onShutdown(const GapShutdownCallback_t &callback);
 
     /**
      * Register a Gap shutdown event handler.
      *
      * @param[in] objPtr Instance used to invoke @p memberPtr.
      * @param[in] memberPtr Shutdown event handler to register.
      */
     template<typename T>
     void onShutdown(T *objPtr, void (T::*memberPtr)(const Gap *)) {
         onShutdown(GapShutdownCallback_t(objPtr, memberPtr));
     }
 
     /**
      * Access the callchain of shutdown event handler.
      *
      * @note To register callbacks, use onShutdown().add(callback).
      *
      * @note To unregister callbacks, use onShutdown().detach(callback).
      *
      * @return A reference to the shutdown event callback chain.
      */
     GapShutdownCallbackChain_t &onShutdown();
 
 #if !defined(DOXYGEN_ONLY)
     /*
      * Constructor from the private implementation.
      */
     Gap(impl::Gap* impl) : impl(impl) {}
 
     /*
      * Restrict copy and move.
      */
     Gap(const Gap&) = delete;
     Gap& operator=(const Gap&) = delete;
 
     /*
      * API reserved for the controller driver to set the random static address.
      * Setting a new random static address while the controller is operating is
      * forbidden by the Bluetooth specification.
      */
     ble_error_t setRandomStaticAddress(const ble::address_t& address);
 
     ble::address_t getRandomStaticAddress();
 #endif // !defined(DOXYGEN_ONLY)
 
 private:
     impl::Gap* impl;
 };
 
 /**
  * @}
  * @}
  */
 
 } // namespace ble
 
 /** @deprecated Use the namespaced ble::Gap instead of the global Gap. */
 using ble::Gap;
 
 #endif // BLE_GAP_GAP_H
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