CU-UP/E1: mirror CU-CP UE ID in CU-UP, clean up messages

- Use the same CU-UP in E1 as in CU-CP: we don't have a separate entity
  to allocate IDs, and we just use the same as the CU-CP
- Correct gNB CU-UP/CP UE IDs in E1AP message types to 32bit
- Set CU UP UE ID explicitly for clarity
- Remove RNTI from E1 messages, E1 does not know what an RNTI is

openair2/COMMON/e1ap_messages_types.h

@@ -156,7 +156,6 @@ typedef struct pdu_session_to_setup_s {
 typedef struct e1ap_bearer_setup_req_s {
   uint32_t gNB_cu_cp_ue_id;
   uint32_t gNB_cu_up_ue_id;
-  rnti_t   rnti;
   uint64_t cipheringAlgorithm;
   uint64_t integrityProtectionAlgorithm;
   char     encryptionKey[128];
@@ -216,8 +215,8 @@ typedef struct pdu_session_setup_s {
 } pdu_session_setup_t;
 
 typedef struct e1ap_bearer_setup_resp_s {
-  uint64_t gNB_cu_cp_ue_id;
-  uint64_t gNB_cu_up_ue_id;
+  uint32_t gNB_cu_cp_ue_id;
+  uint32_t gNB_cu_up_ue_id;
   int numDRBs;
   drb_setup_t DRBList[E1AP_MAX_NUM_DRBS];
   int numPDUSessions;

openair2/E1AP/e1ap.c

@@ -1095,7 +1095,7 @@ static int fill_BEARER_CONTEXT_MODIFICATION_REQUEST(e1ap_setup_req_t *setupReq,
   ieC2->id                         = E1AP_ProtocolIE_ID_id_gNB_CU_UP_UE_E1AP_ID;
   ieC2->criticality                = E1AP_Criticality_reject;
   ieC2->value.present              = E1AP_BearerContextModificationRequestIEs__value_PR_GNB_CU_UP_UE_E1AP_ID;
-  ieC2->value.choice.GNB_CU_UP_UE_E1AP_ID = bearerCxt->gNB_cu_cp_ue_id;
+  ieC2->value.choice.GNB_CU_UP_UE_E1AP_ID = bearerCxt->gNB_cu_up_ue_id;
   /* optional */
   /*  */
   asn1cSequenceAdd(out->protocolIEs.list, E1AP_BearerContextModificationRequestIEs_t, ieC3);

openair2/E1AP/e1ap_api.c

@@ -30,6 +30,7 @@
 #include "openair2/RRC/LTE/MESSAGES/asn1_msg.h"
 #include "openair3/SECU/key_nas_deriver.h"
 #include "openair3/ocp-gtpu/gtp_itf.h"
+#include "openair2/F1AP/f1ap_ids.h"
 #include "e1ap_asnc.h"
 #include "e1ap_common.h"
 #include "e1ap.h"
@@ -136,6 +137,11 @@ void process_e1_bearer_context_setup_req(instance_t instance, e1ap_bearer_setup_
   AssertFatal(inst, "");
   gtpv1u_gnb_create_tunnel_resp_t create_tunnel_resp_N3={0};
 
+  uint32_t gNB_cu_up_ue_id = req ->gNB_cu_cp_ue_id;
+  LOG_I(E1AP, "adding UE with CU-CP UE ID %d and CU-UP UE ID %d\n", req->gNB_cu_cp_ue_id, gNB_cu_up_ue_id);
+  f1_ue_data_t ue_data = {.secondary_ue = req->gNB_cu_cp_ue_id};
+  cu_add_f1_ue_data(gNB_cu_up_ue_id, &ue_data);
+
   // GTP tunnel for UL
   drb_config_N3gtpu_create(req, &create_tunnel_resp_N3, inst->gtpInstN3);
 
@@ -148,6 +154,7 @@ void process_e1_bearer_context_setup_req(instance_t instance, e1ap_bearer_setup_
   fill_e1ap_bearer_setup_resp(resp, req, inst->gtpInstF1U, req->gNB_cu_cp_ue_id, inst->setupReq.remotePortF1U, my_addr);
 
   resp->gNB_cu_cp_ue_id = req->gNB_cu_cp_ue_id;
+  resp->gNB_cu_up_ue_id = gNB_cu_up_ue_id;
   resp->numPDUSessions = req->numPDUSessions;
   for (int i=0; i < req->numPDUSessions; i++) {
     pdu_session_setup_t *pduSetup = resp->pduSession + i;

openair2/RRC/NR/cucp_cuup_direct.c

@@ -163,7 +163,7 @@ static int drb_config_gtpu_create(const protocol_ctxt_t *const ctxt_p,
 
 static void cucp_cuup_bearer_context_setup_direct(e1ap_bearer_setup_req_t *const req, instance_t instance)
 {
-  rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context_by_rnti(RC.nrrrc[instance], req->rnti);
+  rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(RC.nrrrc[instance], req->gNB_cu_cp_ue_id);
   gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
   protocol_ctxt_t ctxt = {0};
   PROTOCOL_CTXT_SET_BY_MODULE_ID(&ctxt, 0, GNB_FLAG_YES, UE->rrc_ue_id, 0, 0, 0);
@@ -212,7 +212,7 @@ static void cucp_cuup_bearer_context_mod_direct(e1ap_bearer_setup_req_t *const r
   if (!NODE_IS_CU(RC.nrrrc[0]->node_type))
     return;
   instance_t gtpInst = getCxt(CUtype, instance)->gtpInst;
-  CU_update_UP_DL_tunnel(req, gtpInst, req->rnti);
+  CU_update_UP_DL_tunnel(req, gtpInst, req->gNB_cu_cp_ue_id);
 }
 
 void cucp_cuup_message_transfer_direct_init(gNB_RRC_INST *rrc) {

openair2/RRC/NR/rrc_gNB.c

@@ -2375,7 +2375,7 @@ static void rrc_CU_process_ue_context_modification_response(MessageDef *msg_p, i
     e1ap_bearer_setup_req_t req = {0};
     req.numPDUSessionsMod = UE->nb_of_pdusessions;
     req.gNB_cu_cp_ue_id = UE->rrc_ue_id;
-    req.rnti = UE->rnti;
+    req.gNB_cu_up_ue_id = UE->rrc_ue_id;
     for (int i = 0; i < req.numPDUSessionsMod; i++) {
       req.pduSessionMod[i].numDRB2Modify = resp->drbs_to_be_setup_length;
       for (int j = 0; j < resp->drbs_to_be_setup_length; j++) {
@@ -2649,6 +2649,13 @@ void rrc_gNB_process_e1_bearer_context_setup_resp(e1ap_bearer_setup_resp_t *resp
   protocol_ctxt_t ctxt = {0};
   PROTOCOL_CTXT_SET_BY_MODULE_ID(&ctxt, 0, GNB_FLAG_YES, resp->gNB_cu_cp_ue_id, 0, 0, 0);
 
+  // currently: we don't have "infrastructure" to save the CU-UP UE ID, so we
+  // assume (and below check) that CU-UP UE ID == CU-CP UE ID
+  AssertFatal(resp->gNB_cu_cp_ue_id == resp->gNB_cu_up_ue_id,
+              "cannot handle CU-UP UE ID different from CU-CP UE ID (%d vs %d)\n",
+              resp->gNB_cu_cp_ue_id,
+              resp->gNB_cu_up_ue_id);
+
   gtpv1u_gnb_create_tunnel_resp_t create_tunnel_resp={0};
   create_tunnel_resp.num_tunnels = resp->numPDUSessions;
   for (int i=0; i < resp->numPDUSessions; i++) {

openair2/RRC/NR/rrc_gNB_NGAP.c

@@ -760,7 +760,6 @@ void rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ(MessageDef *msg_p, instance_t ins
     session->pdusessionTransfer = msg->pdusession_setup_params[i].pdusessionTransfer;
     decodePDUSessionResourceSetup(session);
     bearer_req.gNB_cu_cp_ue_id = msg->gNB_ue_ngap_id;
-    bearer_req.rnti = UE->rnti;
     bearer_req.cipheringAlgorithm = UE->ciphering_algorithm;
     bearer_req.integrityProtectionAlgorithm = UE->integrity_algorithm;
     nr_derive_key(UP_ENC_ALG, UE->ciphering_algorithm, UE->kgnb, (uint8_t *)bearer_req.encryptionKey);