bluetooth: services: hrs: Role fix

Only run ble evt when peripheral role is connected.

Signed-off-by: Sondre Pettersen <sondre.pettersen@nordicsemi.no>
Co-authored-by: Asil Zogby <asil.zogby@nordicsemi.no>

Author: sondrep

doc/nrf-bm/release_notes/release_notes_changelog.rst

@@ -76,7 +76,9 @@ No changes since the latest nRF Connect SDK Bare Metal release.
 Bluetooth LE Services
 ---------------------
 
-No changes since the latest nRF Connect SDK Bare Metal release.
+* :ref:`lib_ble_service_hrs`
+
+   * Changed the :c:func:`ble_hrs_on_ble_evt` function to only handle peripheral-role GAP events.
 
 Libraries for NFC
 -----------------

subsys/bluetooth/services/ble_hrs/hrs.c

@@ -193,6 +193,18 @@ void ble_hrs_on_ble_evt(const ble_evt_t *ble_evt, void *hrs_instance)
 	__ASSERT(ble_evt, "BLE event is NULL");
 	__ASSERT(hrs_instance, "BLE instance is NULL");
 
+	/* Filter:
+	 * Only handle peripheral-role GAP events.
+	 * Central-role events would otherwise overwrite hrs->conn_handle and break notifications
+	 * to the real peer.
+	 */
+	if (ble_evt->header.evt_id >= BLE_GAP_EVT_BASE &&
+	    ble_evt->header.evt_id <= BLE_GAP_EVT_LAST &&
+	    ble_evt->evt.gap_evt.params.connected.role != BLE_GAP_ROLE_PERIPH &&
+	    ble_evt->evt.gap_evt.params.connected.role != BLE_GAP_ROLE_INVALID) {
+		return;
+	}
+
 	switch (ble_evt->header.evt_id) {
 	case BLE_GAP_EVT_CONNECTED:
 		on_connect(hrs_instance, &ble_evt->evt.gap_evt);