Merge pull request #9399 from paul-szczepanek-arm/fix-null-check

BLE: fix missing null checks on Gap event handler

Author: 0xc0170

features/FEATURE_BLE/source/generic/GenericGap.cpp

@@ -64,6 +64,10 @@ static const GapScanningParams default_scan_params;
 static const mbed_error_status_t mixed_scan_api_error =
     MBED_MAKE_ERROR(MBED_MODULE_BLE, MBED_ERROR_CODE_BLE_USE_INCOMPATIBLE_API);
 
+static const mbed_error_status_t illegal_state_error =
+    MBED_MAKE_ERROR(MBED_MODULE_BLE, MBED_ERROR_CODE_BLE_ILLEGAL_STATE);
+
+
 /*
  * Return true if value is included in the range [lower_bound : higher_bound]
  */
@@ -1784,7 +1788,8 @@ void GenericGap::on_disconnection_complete(const pal::GapDisconnectionCompleteEv
 void GenericGap::on_connection_parameter_request(const pal::GapRemoteConnectionParameterRequestEvent &e)
 {
     if (_user_manage_connection_parameter_requests) {
-        _eventHandler->onUpdateConnectionParametersRequest(
+        if (_eventHandler) {
+            _eventHandler->onUpdateConnectionParametersRequest(
                 UpdateConnectionParametersRequestEvent(
                     e.connection_handle,
                     conn_interval_t(e.min_connection_interval),
@@ -1793,6 +1798,9 @@ void GenericGap::on_connection_parameter_request(const pal::GapRemoteConnectionP
                     supervision_timeout_t(e.supervision_timeout)
                 )
             );
+        } else {
+            MBED_ERROR(illegal_state_error, "Event handler required if connection params are user handled");
+        }
     } else {
         _pal_gap.accept_connection_parameter_request(
             e.connection_handle,
@@ -1808,6 +1816,10 @@ void GenericGap::on_connection_parameter_request(const pal::GapRemoteConnectionP
 
 void GenericGap::on_connection_update(const pal::GapConnectionUpdateEvent &e)
 {
+    if (!_eventHandler) {
+        return;
+    }
+
     _eventHandler->onConnectionParametersUpdateComplete(
         ConnectionParametersUpdateCompleteEvent(
             e.status == pal::hci_error_code_t::SUCCESS ? BLE_ERROR_NONE : BLE_ERROR_UNSPECIFIED,

platform/mbed_error.h

@@ -792,6 +792,7 @@ typedef enum _mbed_error_code {
     MBED_DEFINE_SYSTEM_ERROR(AUTHENTICATION_FAILED, 69),                /* 325      Authentication Failed */
     MBED_DEFINE_SYSTEM_ERROR(RBP_AUTHENTICATION_FAILED, 70),            /* 326      Rollback Protection Authentication Failed */
     MBED_DEFINE_SYSTEM_ERROR(BLE_USE_INCOMPATIBLE_API, 71),             /* 327      Concurrent use of incompatible versions of a BLE API */
+    MBED_DEFINE_SYSTEM_ERROR(BLE_ILLEGAL_STATE, 72),                    /* 328      BLE stack entered illegal state */
 
     //Everytime you add a new system error code, you must update
     //Error documentation under Handbook to capture the info on