Do not require F1 System Information when handling new DU

gNB-DU System Information may be sent after setup to update the system
information, and the RRC can "do without". See next commit.

openair2/F1AP/f1ap_cu_interface_management.c

@@ -182,6 +182,7 @@ int CU_handle_F1_SETUP_REQUEST(instance_t instance, sctp_assoc_t assoc_id, uint3
     }
 
     struct F1AP_GNB_DU_System_Information * DUsi=served_cells_item->gNB_DU_System_Information;
+    if (DUsi != NULL) {
       // System Information
       req->cell[i].sys_info = calloc(1, sizeof(*req->cell[i].sys_info));
       AssertFatal(req->cell[i].sys_info != NULL, "out of memory\n");
@@ -194,6 +195,9 @@ int CU_handle_F1_SETUP_REQUEST(instance_t instance, sctp_assoc_t assoc_id, uint3
       sys_info->sib1 = calloc(DUsi->sIB1_message.size, sizeof(char));
       memcpy(sys_info->sib1, DUsi->sIB1_message.buf, DUsi->sIB1_message.size);
       sys_info->sib1_length = DUsi->sIB1_message.size;
+    } else {
+      LOG_D(F1AP, "No SysInfo in F1SetupReq, expecting GNB DU Config Update\n");
+    }
   }
 
   itti_send_msg_to_task(TASK_RRC_GNB, GNB_MODULE_ID_TO_INSTANCE(instance), message_p);

openair2/RRC/NR/rrc_gNB_du.c

@@ -112,15 +112,10 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
 
   // if there is no system info or no SIB1 and we run in SA mode, we cannot handle it
   const f1ap_gnb_du_system_info_t *sys_info = req->cell[0].sys_info;
-  if (sys_info == NULL || sys_info->mib == NULL || (sys_info->sib1 == NULL && get_softmodem_params()->sa)) {
-    LOG_E(NR_RRC, "no system information provided by DU, rejecting\n");
-    f1ap_setup_failure_t fail = {.cause = F1AP_CauseProtocol_semantic_error};
-    rrc->mac_rrc.f1_setup_failure(assoc_id, &fail);
-    return;
-  }
-
-  /* do we need the MIB? for the moment, just check it is valid, then drop it */
   NR_BCCH_BCH_Message_t *mib = NULL;
+  NR_SIB1_t *sib1 = NULL;
+
+  if (sys_info != NULL && sys_info->mib != NULL && !(sys_info->sib1 == NULL && get_softmodem_params()->sa)) {
     asn_dec_rval_t dec_rval =
         uper_decode_complete(NULL, &asn_DEF_NR_BCCH_BCH_Message, (void **)&mib, sys_info->mib, sys_info->mib_length);
     if (dec_rval.code != RC_OK || mib->message.present != NR_BCCH_BCH_MessageType_PR_mib
@@ -132,7 +127,6 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
       return;
     }
 
-  NR_SIB1_t *sib1 = NULL;
     if (sys_info->sib1) {
       dec_rval = uper_decode_complete(NULL, &asn_DEF_NR_SIB1, (void **)&sib1, sys_info->sib1, sys_info->sib1_length);
       if (dec_rval.code != RC_OK) {
@@ -145,7 +139,7 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
       if (LOG_DEBUGFLAG(DEBUG_ASN1))
         xer_fprint(stdout, &asn_DEF_NR_SIB1, sib1);
     }
-
+  }
   LOG_I(RRC, "Accepting DU %ld (%s), sending F1 Setup Response\n", req->gNB_DU_id, req->gNB_DU_name);
 
   // we accept the DU
@@ -159,10 +153,12 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
   du->setup_req = malloc(sizeof(*du->setup_req));
   AssertFatal(du->setup_req != NULL, "out of memory\n");
   *du->setup_req = *req;
+  if (mib != NULL && sib1 != NULL) {
     du->mib = mib->message.choice.mib;
     mib->message.choice.mib = NULL;
     ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_MessageType, mib);
     du->sib1 = sib1;
+  }
   RB_INSERT(rrc_du_tree, &rrc->dus, du);
   rrc->num_dus++;