find_or_next_pdu_session for E1 Bearer Context Modification Request

- this function refers to the E1 Bearer Context Modification Request
- therefore it has to return pdu_session_to_mod_t*
- and takes in input e1ap_bearer_mod_req_t *

openair2/RRC/NR/cucp_cuup_direct.c

@@ -31,7 +31,7 @@ static void cucp_cuup_bearer_context_setup_direct(sctp_assoc_t assoc_id, const e
   e1_bearer_context_setup(req);
 }
 
-static void cucp_cuup_bearer_context_modif_direct(sctp_assoc_t assoc_id, const e1ap_bearer_setup_req_t *req)
+static void cucp_cuup_bearer_context_modif_direct(sctp_assoc_t assoc_id, const e1ap_bearer_mod_req_t *req)
 {
   AssertFatal(assoc_id == -1, "illegal assoc_id %d, impossible for integrated CU\n", assoc_id);
   e1_bearer_context_modif(req);

openair2/RRC/NR/rrc_gNB.c

@@ -910,6 +910,24 @@ rrc_gNB_generate_dedicatedRRCReconfiguration_release(
   nr_rrc_transfer_protected_rrc_message(rrc, ue_p, DCCH, buffer, size);
 }
 
+/* \brief find existing PDU session inside E1AP Bearer Modif message, or
+ * point to new one.
+ * \param bearer_modif E1AP Bearer Modification Message
+ * \param pdu_id PDU session ID
+ * \return pointer to existing PDU session, or to new/unused one. */
+static pdu_session_to_mod_t *find_or_next_pdu_session(e1ap_bearer_mod_req_t *bearer_modif, int pdu_id)
+{
+  for (int i = 0; i < bearer_modif->numPDUSessionsMod; ++i) {
+    if (bearer_modif->pduSessionMod[i].sessionId == pdu_id)
+      return &bearer_modif->pduSessionMod[i];
+  }
+  /* E1AP Bearer Modification has no PDU session to modify with that ID, create
+   * new entry */
+  DevAssert(bearer_modif->numPDUSessionsMod < E1AP_MAX_NUM_PDU_SESSIONS - 1);
+  bearer_modif->numPDUSessionsMod += 1;
+  return &bearer_modif->pduSessionMod[bearer_modif->numPDUSessionsMod - 1];
+}
+
 static void cuup_notify_reestablishment(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p)
 {
   e1ap_bearer_mod_req_t req = {0};
@@ -1820,7 +1838,7 @@ static void f1u_gtp_update(rrc_pdu_session_param_t *pdu_ue, const f1ap_drb_to_be
 static void e1_send_bearer_updates(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, int n, f1ap_drb_to_be_setup_t *drbs)
 {
   // we assume the same UE ID in CU-UP and CU-CP
-  e1ap_bearer_setup_req_t req = {
+  e1ap_bearer_mod_req_t req = {
     .gNB_cu_cp_ue_id = UE->rrc_ue_id,
     .gNB_cu_up_ue_id = UE->rrc_ue_id,
   };
@@ -1832,7 +1850,7 @@ static void e1_send_bearer_updates(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, int n, f
       LOG_E(RRC, "UE %d: UE Context Modif Response: no PDU session for DRB ID %ld\n", UE->rrc_ue_id, drb_f1->drb_id);
       continue;
     }
-    pdu_session_to_setup_t *pdu_e1 = find_or_next_pdu_session(&req, pdu_ue->param.pdusession_id);
+    pdu_session_to_mod_t *pdu_e1 = find_or_next_pdu_session(&req, pdu_ue->param.pdusession_id);
     DevAssert(pdu_e1 != NULL);
     pdu_e1->sessionId = pdu_ue->param.pdusession_id;
     DRB_nGRAN_to_setup_t *drb_e1 = &pdu_e1->DRBnGRanModList[pdu_e1->numDRB2Modify];