Refactor F1 Setup Req/DU config update: transport slices via F1 and read config

In the DU, read slice information from the DU config file. Handle
multiple slices within the F1 Setup Request structure representation,
and forward it via F1 to CU. The DU slice information is stored in the
setup request structure.

openair2/COMMON/f1ap_messages_types.h

@@ -129,10 +129,9 @@ typedef struct f1ap_served_cell_info_t {
   /* Tracking area code */
   uint32_t *tac;
 
-  // Number of slide support items (max 16, could be increased to as much as 1024)
+  // Number of slice support items (max 16, could be increased to as much as 1024)
   uint16_t num_ssi;
-  uint8_t sst;
-  uint8_t sd;
+  nssai_t nssai[16];
 
   f1ap_mode_t mode;
   union {

openair2/F1AP/f1ap_cu_interface_management.c

@@ -76,6 +76,32 @@ static uint8_t *cp_octet_string(const OCTET_STRING_t *os, int *len)
   return buf;
 }
 
+static int read_slice_info(const F1AP_ServedPLMNs_Item_t *plmn, nssai_t *nssai, int max_nssai)
+{
+  if (plmn->iE_Extensions == NULL)
+    return 0;
+
+  const F1AP_ProtocolExtensionContainer_10696P34_t *p = (F1AP_ProtocolExtensionContainer_10696P34_t *)plmn->iE_Extensions;
+  if (p->list.count == 0)
+    return 0;
+
+  const F1AP_ServedPLMNs_ItemExtIEs_t *splmn = p->list.array[0];
+  DevAssert(splmn->id == F1AP_ProtocolIE_ID_id_TAISliceSupportList);
+  DevAssert(splmn->extensionValue.present == F1AP_ServedPLMNs_ItemExtIEs__extensionValue_PR_SliceSupportList);
+  const F1AP_SliceSupportList_t *ssl = &splmn->extensionValue.choice.SliceSupportList;
+  AssertFatal(ssl->list.count <= max_nssai, "cannot handle more than 16 slices\n");
+  for (int s = 0; s < ssl->list.count; ++s) {
+    const F1AP_SliceSupportItem_t *sl = ssl->list.array[s];
+    nssai_t *n = &nssai[s];
+    OCTET_STRING_TO_INT8(&sl->sNSSAI.sST, n->sst);
+    n->sd = 0xffffff;
+    if (sl->sNSSAI.sD != NULL)
+      OCTET_STRING_TO_INT24(sl->sNSSAI.sD, n->sd);
+  }
+
+  return ssl->list.count;
+}
+
 /*
     F1 Setup
 */
@@ -152,6 +178,9 @@ int CU_handle_F1_SETUP_REQUEST(instance_t instance, sctp_assoc_t assoc_id, uint3
     req->cell[i].info.nr_pci = servedCellInformation->nRPCI;
     LOG_D(F1AP, "req->nr_pci[%d] %d \n", i, req->cell[i].info.nr_pci);
 
+    AssertFatal(servedCellInformation->servedPLMNs.list.count == 1, "only one PLMN handled\n");
+    req->cell[i].info.num_ssi = read_slice_info(servedCellInformation->servedPLMNs.list.array[0], req->cell[i].info.nssai, 16);
+
     // FDD Cells
     if (servedCellInformation->nR_Mode_Info.present==F1AP_NR_Mode_Info_PR_fDD) {
       req->cell[i].info.mode = F1AP_MODE_FDD;
@@ -507,6 +536,10 @@ int CU_handle_gNB_DU_CONFIGURATION_UPDATE(instance_t instance, sctp_assoc_t asso
       req->cell_to_add[i].info.nr_pci = servedCellInformation->nRPCI;
       LOG_D(F1AP, "req->nr_pci[%d] %d \n", i, req->cell_to_add[i].info.nr_pci);
 
+      AssertFatal(servedCellInformation->servedPLMNs.list.count == 1, "only one PLMN handled\n");
+      req->cell_to_add[i].info.num_ssi =
+          read_slice_info(servedCellInformation->servedPLMNs.list.array[0], req->cell_to_add[i].info.nssai, 16);
+
       // FDD Cells
       if (servedCellInformation->nR_Mode_Info.present == F1AP_NR_Mode_Info_PR_fDD) {
         req->cell_to_add[i].info.mode = F1AP_MODE_FDD;

openair2/F1AP/f1ap_du_interface_management.c

@@ -119,13 +119,13 @@ static F1AP_Served_Cell_Information_t encode_served_cell_info(const f1ap_served_
     served_plmns_itemExtIEs->extensionValue.present = F1AP_ServedPLMNs_ItemExtIEs__extensionValue_PR_SliceSupportList;
     F1AP_SliceSupportList_t *slice_support_list = &served_plmns_itemExtIEs->extensionValue.choice.SliceSupportList;
 
-    AssertFatal(c->num_ssi == 1, "can only encode one slice\n");
     for (int s = 0; s < c->num_ssi; s++) {
       asn1cSequenceAdd(slice_support_list->list, F1AP_SliceSupportItem_t, slice);
-      INT8_TO_OCTET_STRING(c->sst, &slice->sNSSAI.sST);
-      if (c->sd != 0xffffff) {
+      const nssai_t *nssai = &c->nssai[s];
+      INT8_TO_OCTET_STRING(nssai->sst, &slice->sNSSAI.sST);
+      if (nssai->sd != 0xffffff) {
         asn1cCalloc(slice->sNSSAI.sD, tmp);
-        INT24_TO_OCTET_STRING(c->sd, tmp);
+        INT24_TO_OCTET_STRING(nssai->sd, tmp);
       }
     }
   }

openair2/GNB_APP/gnb_config.c

@@ -1075,6 +1075,8 @@ static int read_du_cell_info(configmodule_interface_t *cfg,
     PLMNParams[I].chkPptr = &(config_check_PLMNParams[I]);
   paramlist_def_t PLMNParamList = {GNB_CONFIG_STRING_PLMN_LIST, NULL, 0};
   config_getlist(cfg, &PLMNParamList, PLMNParams, sizeof(PLMNParams) / sizeof(paramdef_t), aprefix);
+  AssertFatal(PLMNParamList.numelt > 0, "need to have a PLMN in PLMN section\n");
+  AssertFatal(PLMNParamList.numelt == 1, "cannot have more than one PLMN\n");
 
   // if fronthaul is F1, require gNB_DU_ID, else use gNB_ID
   if (separate_du) {
@@ -1099,8 +1101,20 @@ static int read_du_cell_info(configmodule_interface_t *cfg,
               info->plmn.mnc_digit_length);
   info->nr_cellid = (uint64_t) * (GNBParamList.paramarray[0][GNB_NRCELLID_IDX].u64ptr);
 
-  LOG_W(GNB_APP, "no slices transported via F1 Setup Request!\n");
-  info->num_ssi = 0;
+  paramdef_t SNSSAIParams[] = GNBSNSSAIPARAMS_DESC;
+  paramlist_def_t SNSSAIParamList = {GNB_CONFIG_STRING_SNSSAI_LIST, NULL, 0};
+  checkedparam_t config_check_SNSSAIParams[] = SNSSAIPARAMS_CHECK;
+  for (int J = 0; J < sizeofArray(SNSSAIParams); ++J)
+    SNSSAIParams[J].chkPptr = &(config_check_SNSSAIParams[J]);
+  char snssaistr[MAX_OPTNAME_SIZE * 2 + 8];
+  sprintf(snssaistr, "%s.[0].%s.[0]", GNB_CONFIG_STRING_GNB_LIST, GNB_CONFIG_STRING_PLMN_LIST);
+  config_getlist(config_get_if(), &SNSSAIParamList, SNSSAIParams, sizeofArray(SNSSAIParams), snssaistr);
+  info->num_ssi = SNSSAIParamList.numelt;
+  for (int s = 0; s < info->num_ssi; ++s) {
+    info->nssai[s].sst = *SNSSAIParamList.paramarray[s][GNB_SLICE_SERVICE_TYPE_IDX].uptr;
+    info->nssai[s].sd = *SNSSAIParamList.paramarray[s][GNB_SLICE_DIFFERENTIATOR_IDX].uptr;
+    AssertFatal(info->nssai[s].sd <= 0xffffff, "SD cannot be bigger than 0xffffff, but is %d\n", info->nssai[s].sd);
+  }
 
   return 1;
 }

openair2/RRC/NR/rrc_gNB_du.c

@@ -258,8 +258,8 @@ static void update_cell_info(nr_rrc_du_container_t *du, const f1ap_served_cell_i
   if (new_ci->tac != NULL)
     *ci->tac = *new_ci->tac;
   ci->num_ssi = new_ci->num_ssi;
-  ci->sst = new_ci->sst;
-  ci->sd = new_ci->sd;
+  for (int s = 0; s < new_ci->num_ssi; ++s)
+    ci->nssai[s] = new_ci->nssai[s];
   ci->mode = new_ci->mode;
   if (ci->mode == F1AP_MODE_TDD)
     ci->tdd = new_ci->tdd;