Trigger UE context setup req after E1 bearer setup resp

As of this commit, since we now send the UE security command as a DL NAS
message, there is no F1 UE Context setup request. Hence, instead of
sending a UE context modif request, send the UE context setup request
after the E1 bearer setup response (which logically also makes more
sense, as the E1 setup procedure comes before the F1 setup procedure).

openair2/RRC/NR/rrc_gNB.c

@@ -1725,6 +1725,7 @@ static void rrc_CU_process_ue_context_setup_response(MessageDef *msg_p, instance
     return;
   }
   gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
+  UE->f1_ue_context_active = true;
 
   NR_CellGroupConfig_t *cellGroupConfig = NULL;
   asn_dec_rval_t dec_rval = uper_decode_complete(NULL,
@@ -1743,13 +1744,14 @@ static void rrc_CU_process_ue_context_setup_response(MessageDef *msg_p, instance
     xer_fprint(stdout, &asn_DEF_NR_CellGroupConfig, UE->masterCellGroup);
 
   if (resp->drbs_to_be_setup_length > 0) {
-    AssertFatal(resp->srbs_to_be_setup_length > 0 && resp->srbs_to_be_setup[0].srb_id == 2, "logic bug: we set up DRBs, so need to have both SRB1&SRB2\n");
+    /* Note: we would ideally check that SRB2 is acked, but at least LiteOn DU
+     * seems buggy and does not ack, so simply check that locally we activated */
+    AssertFatal(UE->Srb[1].Active && UE->Srb[2].Active, "SRBs 1 and 2 must be active during DRB Establishment");
     e1_send_bearer_updates(rrc, UE, resp->drbs_to_be_setup_length, resp->drbs_to_be_setup);
   }
 
-  /* at this point, we don't have to do anything: the UE context setup request
-   * includes the Security Command, whose response will trigger the following
-   * messages (UE capability, to be specific) */
+  protocol_ctxt_t ctxt = {.rntiMaybeUEid = resp->gNB_CU_ue_id, .module_id = instance};
+  rrc_gNB_generate_dedicatedRRCReconfiguration(&ctxt, ue_context_p);
 }
 
 static void rrc_CU_process_ue_context_release_request(MessageDef *msg_p)
@@ -1996,48 +1998,12 @@ void rrc_gNB_process_e1_bearer_context_setup_resp(e1ap_bearer_setup_resp_t *resp
     }
   }
 
-  /* Instruction towards the DU for SRB2 configuration */
-  int nb_srb = 0;
-  f1ap_srb_to_be_setup_t srbs[1] = {0};
-  if (UE->Srb[2].Active == 0) {
-    activate_srb(UE, 2);
-    nb_srb = 1;
-    srbs[0].srb_id = 2;
-    srbs[0].lcid = 2;
-  }
-
-  if (!UE->as_security_active) {
-    /* no AS security active, need to activate security before data*/
-    protocol_ctxt_t ctxt = {.rntiMaybeUEid = UE->rrc_ue_id};
-    rrc_gNB_generate_SecurityModeCommand(&ctxt, ue_context_p);
-  }
-
-  /* Gather UE capability if present */
-  cu_to_du_rrc_information_t cu2du = {0};
-  cu_to_du_rrc_information_t *cu2du_p = NULL;
-  if (UE->ue_cap_buffer.len > 0 && UE->ue_cap_buffer.buf != NULL) {
-    cu2du_p = &cu2du;
-    cu2du.uE_CapabilityRAT_ContainerList = UE->ue_cap_buffer.buf;
-    cu2du.uE_CapabilityRAT_ContainerList_length = UE->ue_cap_buffer.len;
-  }
+  AssertFatal(UE->as_security_active, "logic bug: security should be active when activating DRBs\n");
 
-  f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
-  RETURN_IF_INVALID_ASSOC_ID(ue_data);
-  f1ap_ue_context_modif_req_t ue_context_modif_req = {
-      .gNB_CU_ue_id = UE->rrc_ue_id,
-      .gNB_DU_ue_id = ue_data.secondary_ue,
-      .plmn.mcc = rrc->configuration.mcc[0],
-      .plmn.mnc = rrc->configuration.mnc[0],
-      .plmn.mnc_digit_length = rrc->configuration.mnc_digit_length[0],
-      .nr_cellid = rrc->nr_cellid,
-      .servCellId = 0, /* TODO: correct value? */
-      .srbs_to_be_setup_length = nb_srb,
-      .srbs_to_be_setup = srbs,
-      .drbs_to_be_setup_length = nb_drb,
-      .drbs_to_be_setup = drbs,
-      .cu_to_du_rrc_information = cu2du_p,
-  };
-  rrc->mac_rrc.ue_context_modification_request(ue_data.du_assoc_id, &ue_context_modif_req);
+  if (!UE->f1_ue_context_active)
+    rrc_gNB_generate_UeContextSetupRequest(rrc, ue_context_p, nb_drb, drbs);
+  else
+    rrc_gNB_generate_UeContextModificationRequest(rrc, ue_context_p, nb_drb, drbs, 0, NULL);
 }
 
 /**