cu_cp: remove rrc reconfiguration from initial context setup routine if no pdu sessions are setup

Author: FabianEckermann

lib/cu_cp/routines/initial_context_setup_routine.cpp

@@ -134,33 +134,10 @@ void initial_context_setup_routine::operator()(
     if (request.nas_pdu.has_value()) {
       handle_nas_pdu(request.nas_pdu.value().copy());
     }
-
   } else {
-    // prepare RRC Reconfiguration and call RRC UE notifier
-    if (!fill_rrc_reconfig_args(rrc_reconfig_args,
-                                ue_context_setup_request.srbs_to_be_setup_list,
-                                {} /* No DRB to setup */,
-                                {} /* No extra DRB to be removed */,
-                                ue_context_setup_response.du_to_cu_rrc_info,
-                                request.nas_pdu.has_value() ? std::vector<byte_buffer>{request.nas_pdu.value().copy()}
-                                                            : std::vector<byte_buffer>{},
-                                rrc_ue.generate_meas_config(std::nullopt),
-                                false /* No SRBs to reestablish */,
-                                false /* No DRBs to reestablish */,
-                                false /* No keys to update */,
-                                {} /* No SIB1 */,
-                                logger)) {
-      logger.warning("ue={}: \"{}\" Failed to fill RRCReconfiguration", request.ue_index, name());
-      handle_failure();
-      CORO_EARLY_RETURN(make_unexpected(fail_msg));
-    }
-
-    CORO_AWAIT_VALUE(rrc_reconfig_result, rrc_ue.handle_rrc_reconfiguration_request(rrc_reconfig_args));
-    // Handle RRC Reconfiguration result
-    if (not rrc_reconfig_result) {
-      logger.warning("ue={}: \"{}\" RRC Reconfiguration failed", request.ue_index, name());
-      handle_failure();
-      CORO_EARLY_RETURN(make_unexpected(fail_msg));
+    // Handle NAS PDUs from Initial Context Setup Request
+    if (request.nas_pdu.has_value()) {
+      handle_nas_pdu(request.nas_pdu.value().copy());
     }
   }
 

lib/cu_cp/routines/initial_context_setup_routine.h

@@ -60,7 +60,6 @@ class initial_context_setup_routine
   bool                                      ue_capability_transfer_result = false; // to query the UE capabilities
   cu_cp_pdu_session_resource_setup_response pdu_session_setup_response;
   bool                                      security_mode_command_result = false;
-  bool                                      rrc_reconfig_result          = false; // the final UE reconfiguration
   ngap_init_context_setup_failure           fail_msg;
   ngap_init_context_setup_response          resp_msg;
 };

lib/cu_cp/routines/mobility/inter_du_handover_routine.cpp

@@ -133,7 +133,7 @@ void inter_du_handover_routine::operator()(coro_context<async_task<cu_cp_inter_d
 
   // Inform CU-UP about new DL tunnels.
   {
-    // get securtiy context of target UE
+    // get security context of target UE
     if (!target_ue->get_security_manager().is_security_context_initialized()) {
       logger.warning(
           "ue={}: \"{}\" failed. Cause: Security context not initialized", target_ue->get_ue_index(), name());

tests/unittests/cu_cp/mobility/inter_cu_handover_routine_test.cpp

@@ -55,7 +55,7 @@ class inter_cu_handover_routine_test : public mobility_test
         generate_ul_rrc_message_transfer(int_to_gnb_cu_ue_f1ap_id(0),
                                          int_to_gnb_du_ue_f1ap_id(0),
                                          srb_id_t::srb1,
-                                         make_byte_buffer("000900410004015f741fe0804bf183fc980605b7").value());
+                                         make_byte_buffer("000800410004015f741fe0804bf183fcaa6e9699").value());
     test_logger.info("Injecting UL RRC message (RRC Measurement Report)");
     f1c_gw.get_du(source_du_index).on_new_message(ul_rrc_msg);
   }

tests/unittests/cu_cp/mobility/inter_du_handover_routine_test.cpp

@@ -59,7 +59,7 @@ class inter_du_handover_routine_test : public mobility_test
         generate_ul_rrc_message_transfer(int_to_gnb_cu_ue_f1ap_id(0),
                                          int_to_gnb_du_ue_f1ap_id(0),
                                          srb_id_t::srb1,
-                                         make_byte_buffer("000900410004015f741fe0804bf183fc980605b7").value());
+                                         make_byte_buffer("000800410004015f741fe0804bf183fcaa6e9699").value());
     test_logger.info("Injecting UL RRC message (RRC Measurement Report)");
     f1c_gw.get_du(source_du_index).on_new_message(ul_rrc_msg);
   }
@@ -146,7 +146,7 @@ class inter_du_handover_routine_test : public mobility_test
     f1ap_message rrc_recfg_complete = generate_ul_rrc_message_transfer(int_to_gnb_cu_ue_f1ap_id(0),
                                                                        int_to_gnb_du_ue_f1ap_id(0),
                                                                        srb_id_t::srb1,
-                                                                       make_byte_buffer("80000a00ddc7574a").value());
+                                                                       make_byte_buffer("8000080035c41efd").value());
     f1c_gw.get_du(target_du_index).on_new_message(rrc_recfg_complete);
   }