Merge remote-tracking branch 'origin/fix-pdu-session-release-transfer' into...

Merge remote-tracking branch 'origin/fix-pdu-session-release-transfer' into integration_2025_w49 (!3780)

NGAP: fix PDU Session Release Response

1. Refactor NG UE Context Release Request

  - Removed incorrect UE Context Release Response code (not in 3GPP TS
    38.413)
  - Fixed UE Context Release Request to use correct PDU Session Resource
    List structure
  - Removed incorrect use of pdusession_release_t type

2. Fix PDU Session Release Response

  - Added missing mandatory PDUSessionResourceReleaseResponseTransfer IE
  - Implemented encode_ngap_pdusession_release_response_transfer()
    function
  - Fixed Release Command handler to correctly decode Cause from command
    transfer
  - Split Command/Response struct type definitions to prevent mixing

common/utils/telnetsrv/telnetsrv_ci.c

@@ -348,7 +348,7 @@ static int trigger_ngap_pdu_session_release(char *buf, int debug, telnet_printfu
     if (sid < 1 || sid > 255) {
       ERROR_MSG_RET("Invalid pdusession_id(int): %s (must be between 1 and 255)\n", tokens[i]);
     }
-    msg->pdusession_release_params[nb_sessions++].pdusession_id = sid;
+    msg->pdusession_ids[nb_sessions++] = sid;
   }
 
   msg->nb_pdusessions_torelease = nb_sessions;
@@ -356,7 +356,7 @@ static int trigger_ngap_pdu_session_release(char *buf, int debug, telnet_printfu
   if (prnt) {
     prnt("Triggering NGAP PDU Session Release for gNB_ue_ngap_id=%d: releasing pdusession_id=%d", gNB_ue_ngap_id);
     for (int i = 0; i < nb_sessions; ++i) {
-      prnt(" %d,", msg->pdusession_release_params[i].pdusession_id);
+      prnt(" %d,", msg->pdusession_ids[i]);
     }
     prnt("\n");
   }

openair2/COMMON/ngap_messages_def.h

@@ -64,7 +64,6 @@ MESSAGE_DEF(NGAP_UE_CAPABILITIES_IND       , MESSAGE_PRIORITY_MED, ngap_ue_cap_i
 MESSAGE_DEF(NGAP_INITIAL_CONTEXT_SETUP_RESP, MESSAGE_PRIORITY_MED, ngap_initial_context_setup_resp_t, ngap_initial_context_setup_resp)
 MESSAGE_DEF(NGAP_INITIAL_CONTEXT_SETUP_FAIL, MESSAGE_PRIORITY_MED, ngap_initial_context_setup_fail_t, ngap_initial_context_setup_fail)
 MESSAGE_DEF(NGAP_NAS_NON_DELIVERY_IND      , MESSAGE_PRIORITY_MED, ngap_nas_non_delivery_ind_t      , ngap_nas_non_delivery_ind)
-MESSAGE_DEF(NGAP_UE_CONTEXT_RELEASE_RESP   , MESSAGE_PRIORITY_MED, ngap_ue_release_resp_t           , ngap_ue_release_resp)
 MESSAGE_DEF(NGAP_UE_CONTEXT_RELEASE_COMPLETE, MESSAGE_PRIORITY_MED, ngap_ue_release_complete_t      , ngap_ue_release_complete)
 MESSAGE_DEF(NGAP_UE_CTXT_MODIFICATION_RESP , MESSAGE_PRIORITY_MED, ngap_ue_ctxt_modification_resp_t , ngap_ue_ctxt_modification_resp)
 MESSAGE_DEF(NGAP_UE_CTXT_MODIFICATION_FAIL , MESSAGE_PRIORITY_MED, ngap_ue_ctxt_modification_fail_t , ngap_ue_ctxt_modification_fail)

openair2/COMMON/ngap_messages_types.h

@@ -47,7 +47,6 @@
 #define NGAP_UE_CAPABILITIES_IND(mSGpTR)        (mSGpTR)->ittiMsg.ngap_ue_cap_info_ind
 #define NGAP_INITIAL_CONTEXT_SETUP_RESP(mSGpTR) (mSGpTR)->ittiMsg.ngap_initial_context_setup_resp
 #define NGAP_INITIAL_CONTEXT_SETUP_FAIL(mSGpTR) (mSGpTR)->ittiMsg.ngap_initial_context_setup_fail
-#define NGAP_UE_CONTEXT_RELEASE_RESP(mSGpTR)    (mSGpTR)->ittiMsg.ngap_ue_release_resp
 #define NGAP_NAS_NON_DELIVERY_IND(mSGpTR)       (mSGpTR)->ittiMsg.ngap_nas_non_delivery_ind
 #define NGAP_UE_CTXT_MODIFICATION_RESP(mSGpTR)  (mSGpTR)->ittiMsg.ngap_ue_ctxt_modification_resp
 #define NGAP_UE_CTXT_MODIFICATION_FAIL(mSGpTR)  (mSGpTR)->ittiMsg.ngap_ue_ctxt_modification_fail
@@ -733,12 +732,6 @@ typedef struct ngap_ue_ctxt_modification_resp_s {
   uint32_t  gNB_ue_ngap_id;
 } ngap_ue_ctxt_modification_resp_t;
 
-typedef struct ngap_ue_release_complete_s {
-  uint32_t gNB_ue_ngap_id;
-  int num_pdu_sessions;
-  uint32_t pdu_session_id[256];
-} ngap_ue_release_complete_t;
-
 //-------------------------------------------------------------------------------------------//
 // NGAP -> RRC messages
 typedef struct ngap_downlink_nas_s {
@@ -862,20 +855,24 @@ typedef struct ngap_ue_release_command_s {
 
 //-------------------------------------------------------------------------------------------//
 // NGAP <-- RRC messages
-typedef struct pdusession_release_s {
-  /* Unique pdusession_id for the UE. */
-  uint8_t                     pdusession_id;
-  byte_array_t data;
-} pdusession_release_t;
-
 typedef struct ngap_ue_release_req_s {
-  uint32_t             gNB_ue_ngap_id;
-  /* Number of pdusession resource in the list */
+  // RAN UE NGAP ID (mandatory)
+  uint32_t gNB_ue_ngap_id;
+  // PDU Session Resource List (optional)
   uint16_t nb_of_pdusessions;
-  /* list of pdusession resource by RRC layers */
-  pdusession_release_t pdusessions[NGAP_MAX_PDU_SESSION];
+  uint8_t pdusession_ids[NGAP_MAX_PDU_SESSION];
+  // Cause (mandatory)
   ngap_cause_t cause;
-} ngap_ue_release_req_t, ngap_ue_release_resp_t;
+} ngap_ue_release_req_t;
+
+typedef struct {
+  // RAN UE NGAP ID (mandatory)
+  uint32_t gNB_ue_ngap_id;
+  // PDU Session Resource List (optional)
+  uint16_t num_pdu_sessions;
+  // PDU Session ID (mandatory)
+  uint8_t pdu_session_id[NGAP_MAX_PDU_SESSION];
+} ngap_ue_release_complete_t;
 
 typedef struct ngap_pdusession_modify_req_s {
   /* AMF UE id  */
@@ -915,14 +912,19 @@ typedef struct ngap_pdusession_release_command_s {
   /* The NAS PDU should be forwarded by the RRC layer to the NAS layer */
   byte_array_t nas_pdu;
 
-  /* Number of pdusession to be released in the list */
+  // PDU Session Resource to Release List (mandatory)
   uint16_t nb_pdusessions_torelease;
-
-  /* PDUSession release command */
-  pdusession_release_t pdusession_release_params[NGAP_MAX_PDU_SESSION];
+  uint16_t pdusession_ids[NGAP_MAX_PDU_SESSION];
 
 } ngap_pdusession_release_command_t;
 
+typedef struct pdusession_release_s {
+  // PDU Session ID (mandatory)
+  uint8_t pdusession_id;
+  // PDU Session Resource Release Response Transfer (mandatory)
+  byte_array_t pdusession_release_response_transfer;
+} pdusession_release_t;
+
 typedef struct ngap_pdusession_release_resp_s {
   // AMF UE NGAP ID
   uint64_t amf_ue_ngap_id;

openair2/RRC/NR/rrc_gNB.c

@@ -3182,10 +3182,6 @@ void *rrc_gnb_task(void *args_p) {
         rrc_gNB_process_dc_overall_timeout(instance, &X2AP_ENDC_DC_OVERALL_TIMEOUT(msg_p));
         break;
 
-      case NGAP_UE_CONTEXT_RELEASE_REQ:
-        rrc_gNB_process_NGAP_UE_CONTEXT_RELEASE_REQ(msg_p, instance);
-        break;
-
       case NGAP_UE_CONTEXT_RELEASE_COMMAND:
         rrc_gNB_process_NGAP_UE_CONTEXT_RELEASE_COMMAND(msg_p, instance);
         break;

openair2/RRC/NR/rrc_gNB_NGAP.c

@@ -1049,7 +1049,8 @@ int rrc_gNB_send_NGAP_PDUSESSION_MODIFY_RESP(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE
   return 0;
 }
 
-//------------------------------------------------------------------------------
+/** @brief Send UE Context Release Request (NG-RAN node initiated)
+ * Direction: NG-RAN node -> AMF (8.3.2.2 3GPP TS 38.413) */
 void rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_REQ(const module_id_t gnb_mod_idP,
                                               const rrc_gNB_ue_context_t *const ue_context_pP,
                                               const ngap_cause_t causeP)
@@ -1068,40 +1069,12 @@ void rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_REQ(const module_id_t gnb_mod_idP,
     // PDU Session Resource List (optional)
     FOR_EACH_SEQ_ARR(rrc_pdu_session_param_t *, session, &UE->pduSessions) {
       DevAssert(req->nb_of_pdusessions < NGAP_MAX_PDU_SESSION);
-      req->pdusessions[req->nb_of_pdusessions].pdusession_id = session->param.pdusession_id;
+      req->pdusession_ids[req->nb_of_pdusessions] = session->param.pdusession_id;
       req->nb_of_pdusessions++;
     }
     itti_send_msg_to_task(TASK_NGAP, GNB_MODULE_ID_TO_INSTANCE(gnb_mod_idP), msg);
   }
 }
-/*------------------------------------------------------------------------------*/
-int rrc_gNB_process_NGAP_UE_CONTEXT_RELEASE_REQ(MessageDef *msg_p, instance_t instance)
-{
-  uint32_t gNB_ue_ngap_id;
-  gNB_ue_ngap_id = NGAP_UE_CONTEXT_RELEASE_REQ(msg_p).gNB_ue_ngap_id;
-  rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(RC.nrrrc[instance], gNB_ue_ngap_id);
-
-  if (ue_context_p == NULL) {
-    /* Can not associate this message to an UE index, send a failure to ngAP and discard it! */
-    MessageDef *msg_fail_p;
-    LOG_W(RRC, "[gNB %ld] In NGAP_UE_CONTEXT_RELEASE_REQ: unknown UE from gNB_ue_ngap_id (%u)\n",
-          instance,
-          gNB_ue_ngap_id);
-    msg_fail_p = itti_alloc_new_message(TASK_RRC_GNB, 0, NGAP_UE_CONTEXT_RELEASE_RESP); /* TODO change message ID. */
-    NGAP_UE_CONTEXT_RELEASE_RESP(msg_fail_p).gNB_ue_ngap_id = gNB_ue_ngap_id;
-    // TODO add failure cause when defined!
-    itti_send_msg_to_task(TASK_NGAP, instance, msg_fail_p);
-    return (-1);
-  } else {
-
-    /* Send the response */
-    MessageDef *msg_resp_p;
-    msg_resp_p = itti_alloc_new_message(TASK_RRC_GNB, 0, NGAP_UE_CONTEXT_RELEASE_RESP);
-    NGAP_UE_CONTEXT_RELEASE_RESP(msg_resp_p).gNB_ue_ngap_id = gNB_ue_ngap_id;
-    itti_send_msg_to_task(TASK_NGAP, instance, msg_resp_p);
-    return (0);
-  }
-}
 
 /** @brief Sends the NG Handover Failure from the Target NG-RAN to the AMF */
 void rrc_gNB_send_NGAP_HANDOVER_FAILURE(gNB_RRC_INST *rrc, ngap_handover_failure_t *msg)
@@ -1557,9 +1530,9 @@ int rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(ngap_pdusession_release_comm
         cmd->nb_pdusessions_torelease);
   e1ap_bearer_mod_req_t req = {0};
   for (int pdusession = 0; pdusession < cmd->nb_pdusessions_torelease; pdusession++) {
-    rrc_pdu_session_param_t *pduSession = find_pduSession(&UE->pduSessions, cmd->pdusession_release_params[pdusession].pdusession_id);
+    rrc_pdu_session_param_t *pduSession = find_pduSession(&UE->pduSessions, cmd->pdusession_ids[pdusession]);
     if (!pduSession) {
-      LOG_E(NR_RRC, "Failed to release non-existing PDU Session %d\n", cmd->pdusession_release_params[pdusession].pdusession_id);
+      LOG_E(NR_RRC, "Failed to release non-existing PDU Session %d\n", cmd->pdusession_ids[pdusession]);
       continue;
     }
     if (pduSession->status == PDU_SESSION_STATUS_TORELEASE) {

openair3/NGAP/ngap_gNB_context_management_procedures.c

@@ -191,7 +191,7 @@ int ngap_ue_context_release_req(instance_t instance,
     for (int i = 0; i < ue_release_req_p->nb_of_pdusessions; i++) {
       NGAP_PDUSessionResourceItemCxtRelReq_t     *item;
       item = (NGAP_PDUSessionResourceItemCxtRelReq_t *)calloc(1,sizeof(NGAP_PDUSessionResourceItemCxtRelReq_t));
-      item->pDUSessionID = ue_release_req_p->pdusessions[i].pdusession_id;
+      item->pDUSessionID = ue_release_req_p->pdusession_ids[i];
       asn1cSeqAdd(&ie->value.choice.PDUSessionResourceListCxtRelReq.list, item);
     }
   }

openair3/NGAP/ngap_gNB_handlers.c

@@ -1390,9 +1390,20 @@ static int ngap_gNB_handle_pdusession_release_command(sctp_assoc_t assoc_id, uin
   for (i = 0; i < ie->value.choice.PDUSessionResourceToReleaseListRelCmd.list.count; i++) {
     NGAP_PDUSessionResourceToReleaseItemRelCmd_t *item_p;
     item_p = ie->value.choice.PDUSessionResourceToReleaseListRelCmd.list.array[i];
-    pdusession_release_t *r = &msg->pdusession_release_params[i];
-    r->pdusession_id = item_p->pDUSessionID;
-    r->data = create_byte_array(item_p->pDUSessionResourceReleaseCommandTransfer.size, item_p->pDUSessionResourceReleaseCommandTransfer.buf);
+    msg->pdusession_ids[i] = item_p->pDUSessionID;
+
+    /* PDUSessionResourceReleaseCommandTransfer (Mandatory) */
+    void *decoded = decode_pdusession_transfer(&asn_DEF_NGAP_PDUSessionResourceReleaseCommandTransfer,
+                                               item_p->pDUSessionResourceReleaseCommandTransfer);
+    if (!decoded) {
+      NGAP_ERROR("Failed to decode PDUSessionResourceReleaseCommandTransfer for PDU Session %d\n", msg->pdusession_ids[i]);
+      return -1;
+    }
+    NGAP_PDUSessionResourceReleaseCommandTransfer_t *transfer = decoded;
+    ngap_cause_t cause = decode_ngap_cause(&transfer->cause);
+    NGAP_INFO("PDU Session %d release command: Cause type=%d value=%d\n", msg->pdusession_ids[i], cause.type, cause.value);
+    ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_NGAP_PDUSessionResourceReleaseCommandTransfer, transfer);
+    free(transfer);
   }
 
   itti_send_msg_to_task(TASK_RRC_GNB, ue_desc_p->gNB_instance->instance, message_p);

openair3/NGAP/ngap_gNB_nas_procedures.c

@@ -594,6 +594,24 @@ static byte_array_t encode_ngap_pdusession_setup_response_transfer(const pdusess
   return out;
 }
 
+/** @brief PDU Session Resource Release Response Transfer encoding (9.3.4.21 3GPP TS 38.413)
+ *  The transfer structure contains only an optional Secondary RAT Usage Information IE.
+ *  Since we don't use secondary RAT (MR-DC), we encode an empty structure. */
+static byte_array_t encode_ngap_pdusession_release_response_transfer(void)
+{
+  NGAP_PDUSessionResourceReleaseResponseTransfer_t pdusessionTransfer = {0};
+
+  // Encode
+  asn_encode_to_new_buffer_result_t res = asn_encode_to_new_buffer(NULL,
+                                                                   ATS_ALIGNED_CANONICAL_PER,
+                                                                   &asn_DEF_NGAP_PDUSessionResourceReleaseResponseTransfer,
+                                                                   &pdusessionTransfer);
+  AssertFatal(res.buffer, "ASN1 message encoding failed (%s, %lu)!\n", res.result.failed_type->name, res.result.encoded);
+  ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_NGAP_PDUSessionResourceReleaseResponseTransfer, &pdusessionTransfer);
+  byte_array_t out = {.buf = res.buffer, .len = res.result.encoded};
+  return out;
+}
+
 //------------------------------------------------------------------------------
 int ngap_gNB_initial_ctxt_resp(instance_t instance, ngap_initial_context_setup_resp_t *initial_ctxt_resp_p)
 //------------------------------------------------------------------------------
@@ -1200,22 +1218,28 @@ int ngap_gNB_pdusession_release_resp(instance_t instance, ngap_pdusession_releas
     ie->value.choice.RAN_UE_NGAP_ID = pdusession_release_resp_p->gNB_ue_ngap_id;
   }
 
-  /* optional */
-  if (pdusession_release_resp_p->nb_of_pdusessions_released > 0) {
+  /* PDU Session Resource Released List (mandatory) */
+  {
     asn1cSequenceAdd(out->protocolIEs.list, NGAP_PDUSessionResourceReleaseResponseIEs_t, ie);
     ie->id = NGAP_ProtocolIE_ID_id_PDUSessionResourceReleasedListRelRes;
     ie->criticality = NGAP_Criticality_ignore;
     ie->value.present = NGAP_PDUSessionResourceReleaseResponseIEs__value_PR_PDUSessionResourceReleasedListRelRes;
-    
+
     for (i = 0; i < pdusession_release_resp_p->nb_of_pdusessions_released; i++) {
-      asn1cSequenceAdd(ie->value.choice.PDUSessionResourceReleasedListRelRes.list, NGAP_PDUSessionResourceReleasedItemRelRes_t, item);
+      NGAP_PDUSessionResourceReleasedListRelRes_t *list = &ie->value.choice.PDUSessionResourceReleasedListRelRes;
+      asn1cSequenceAdd(list->list, NGAP_PDUSessionResourceReleasedItemRelRes_t, item);
       pdusession_release_t *r = &pdusession_release_resp_p->pdusession_release[i];
+      /* PDU Session ID (mandatory) */
       item->pDUSessionID = r->pdusession_id;
-      OCTET_STRING_fromBuf(&item->pDUSessionResourceReleaseResponseTransfer, (const char *)r->data.buf, r->data.len);
-      NGAP_DEBUG("pdusession_release_resp: pdusession ID %ld\n", item->pDUSessionID);
+      /* PDU Session Resource Release Response Transfer (mandatory) */
+      // Empty transfer is valid since Secondary RAT Usage Information is optional and not used
+      byte_array_t transfer = encode_ngap_pdusession_release_response_transfer();
+      OCTET_STRING_fromBuf(&item->pDUSessionResourceReleaseResponseTransfer, (const char *)transfer.buf, transfer.len);
+      free_byte_array(transfer);
+      NGAP_DEBUG("PDU Session Resource Release Response: pdusession ID %ld\n", item->pDUSessionID);
     }
   }
-  
+
   if (ngap_gNB_encode_pdu(&pdu, &buffer, &length) < 0) {
     NGAP_ERROR("Failed to encode release response\n");
     /* Encode procedure has failed... */

openair3/NGAP/ngap_msg_includes.h

@@ -58,6 +58,8 @@
 #include "NGAP_PDUSessionResourceSetupResponseTransfer.h"
 #include "NGAP_PDUSessionResourceSetupUnsuccessfulTransfer.h"
 #include "NGAP_PDUSessionResourceToReleaseItemRelCmd.h"
+#include "NGAP_PDUSessionResourceReleaseCommandTransfer.h"
+#include "NGAP_PDUSessionResourceReleaseResponseTransfer.h"
 #include "NGAP_PLMNSupportItem.h"
 #include "NGAP_ProtocolIE-Field.h"
 #include "NGAP_QosFlowAddOrModifyResponseItem.h"