From e991f26ff1575427b45edfb5487926efb492ea68 Mon Sep 17 00:00:00 2001
From: Robert Schmidt <robert.schmidt@openairinterface.org>
Date: Sat, 24 May 2025 12:43:42 +0200
Subject: [PATCH] Factor out NSSAI, to be used in other messages lates

---
 openair2/F1AP/lib/f1ap_interface_management.c | 13 ++--------
 openair2/F1AP/lib/f1ap_lib_common.c           | 24 ++++++++++++++++++-
 openair2/F1AP/lib/f1ap_lib_common.h           |  4 ++++
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/openair2/F1AP/lib/f1ap_interface_management.c b/openair2/F1AP/lib/f1ap_interface_management.c
index 0ac1f8d63a..e6d863f7a3 100644
--- a/openair2/F1AP/lib/f1ap_interface_management.c
+++ b/openair2/F1AP/lib/f1ap_interface_management.c
@@ -394,11 +394,7 @@ static int read_slice_info(const F1AP_ServedPLMNs_Item_t *plmn, nssai_t *nssai,
   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);
+    nssai[s] = decode_nssai(&sl->sNSSAI);
   }
 
   return ssl->list.count;
@@ -418,12 +414,7 @@ static F1AP_ProtocolExtensionContainer_10696P34_t *write_slice_info(int num_ssi,
 
   for (int s = 0; s < num_ssi; s++) {
     asn1cSequenceAdd(slice_support_list->list, F1AP_SliceSupportItem_t, slice);
-    const nssai_t *n = &nssai[s];
-    INT8_TO_OCTET_STRING(n->sst, &slice->sNSSAI.sST);
-    if (n->sd != 0xffffff) {
-      asn1cCalloc(slice->sNSSAI.sD, tmp);
-      INT24_TO_OCTET_STRING(n->sd, tmp);
-    }
+    slice->sNSSAI = encode_nssai(&nssai[s]);
   }
 
   return p;
diff --git a/openair2/F1AP/lib/f1ap_lib_common.c b/openair2/F1AP/lib/f1ap_lib_common.c
index e32f7e6779..0e1d07a71d 100644
--- a/openair2/F1AP/lib/f1ap_lib_common.c
+++ b/openair2/F1AP/lib/f1ap_lib_common.c
@@ -25,7 +25,7 @@
 #include "OCTET_STRING.h"
 #include "common/utils/utils.h"
 #include "common/utils/assertions.h"
-#include "common/utils/utils.h"
+#include "common/utils/oai_asn1.h"
 
 bool eq_f1ap_plmn(const plmn_id_t *a, const plmn_id_t *b)
 {
@@ -115,6 +115,28 @@ uint8_t *cp_octet_string(const OCTET_STRING_t *os, int *len)
   return buf;
 }
 
+F1AP_SNSSAI_t encode_nssai(const nssai_t *nssai)
+{
+  F1AP_SNSSAI_t enc = {0};
+  INT8_TO_OCTET_STRING(nssai->sst, &enc.sST);
+  // see 23.003 sec. 28.4.2: 0xffffff means "no SD"
+  if (nssai->sd != 0xffffff) {
+    asn1cCalloc(enc.sD, tmp);
+    INT24_TO_OCTET_STRING(nssai->sd, tmp);
+  }
+  return enc;
+}
+
+nssai_t decode_nssai(const F1AP_SNSSAI_t *nssai)
+{
+  // see 23.003 sec. 28.4.2: 0xffffff means "no SD"
+  nssai_t dec = { .sd = 0xffffff, };
+  OCTET_STRING_TO_INT8(&nssai->sST, dec.sst);
+  if (nssai->sD != NULL)
+    OCTET_STRING_TO_INT24(nssai->sD, dec.sd);
+  return dec;
+}
+
 F1AP_Cause_t encode_f1ap_cause(f1ap_Cause_t cause, long cause_value)
 {
   F1AP_Cause_t f1_cause = {0};
diff --git a/openair2/F1AP/lib/f1ap_lib_common.h b/openair2/F1AP/lib/f1ap_lib_common.h
index 358a2d5eaf..6a50ba45b2 100644
--- a/openair2/F1AP/lib/f1ap_lib_common.h
+++ b/openair2/F1AP/lib/f1ap_lib_common.h
@@ -30,6 +30,7 @@
 #include "common/utils/ds/byte_array.h"
 
 #include "F1AP_Cause.h"
+#include "F1AP_SNSSAI.h"
 #include "f1ap_messages_types.h"
 
 #ifdef ENABLE_TESTS
@@ -120,6 +121,9 @@ bool eq_f1ap_tx_bandwidth(const struct f1ap_transmission_bandwidth_t *a, const s
 struct OCTET_STRING;
 uint8_t *cp_octet_string(const struct OCTET_STRING *os, int *len);
 
+F1AP_SNSSAI_t encode_nssai(const nssai_t *nssai);
+nssai_t decode_nssai(const F1AP_SNSSAI_t *nssai);
+
 F1AP_Cause_t encode_f1ap_cause(f1ap_Cause_t cause, long cause_value);
 bool decode_f1ap_cause(F1AP_Cause_t f1_cause, f1ap_Cause_t *cause, long *cause_value);