procedure to indicate the release of the RRC connection to upper layers

executables/nr-uesoftmodem.c

@@ -402,6 +402,7 @@ static void trigger_deregistration(int sig)
 {
   if (!stop_immediately) {
     MessageDef *msg = itti_alloc_new_message(TASK_RRC_UE_SIM, 0, NAS_DEREGISTRATION_REQ);
+    NAS_DEREGISTRATION_REQ(msg).cause = AS_DETACH;
     itti_send_msg_to_task(TASK_NAS_NRUE, 0, msg);
     stop_immediately = true;
     static const char m[] = "Press ^C again to trigger immediate shutdown\n";

openair2/COMMON/as_message.h

@@ -327,15 +327,6 @@ typedef struct nas_establish_req_s {
   as_nas_info_t   initialNasMsg;  /* Initial NAS message to transfer      */
 } nas_establish_req_t;
 
-/*
- * fill me
- */
-typedef struct nas_deregistration_req_s {
-  // This dummy element is to avoid CLANG warning: empty struct has size 0 in C, size 1 in C++
-  // To be removed if the structure is filled
-  uint32_t dummy;
-} nas_deregistration_req_t;
-
 /*
  * AS->NAS - NAS signalling connection establishment indication
  * AS transfers the initial NAS message to the NAS.
@@ -406,6 +397,10 @@ typedef struct nas_release_ind_s {
   release_cause_t cause;      /* Release cause            */
 } nas_release_ind_t;
 
+typedef struct nas_deregistration_req_s {
+  release_cause_t cause;
+} nas_deregistration_req_t;
+
 /*
  * --------------------------------------------------------------------------
  *              NAS information transfer

openair2/COMMON/rrc_messages_def.h

@@ -73,6 +73,7 @@ MESSAGE_DEF(NAS_CELL_SELECTION_IND,     MESSAGE_PRIORITY_MED,       NasCellSelec
 MESSAGE_DEF(NAS_PAGING_IND,             MESSAGE_PRIORITY_MED,       NasPagingInd,               nas_paging_ind)
 MESSAGE_DEF(NAS_CONN_ESTABLI_CNF,       MESSAGE_PRIORITY_MED,       NasConnEstabCnf,            nas_conn_establi_cnf)
 MESSAGE_DEF(NAS_CONN_RELEASE_IND,       MESSAGE_PRIORITY_MED,       NasConnReleaseInd,          nas_conn_release_ind)
+MESSAGE_DEF(NR_NAS_CONN_RELEASE_IND,    MESSAGE_PRIORITY_MED,       NRNasConnReleaseInd,        nr_nas_conn_release_ind)
 MESSAGE_DEF(NAS_UPLINK_DATA_CNF,        MESSAGE_PRIORITY_MED,       NasUlDataCnf,               nas_ul_data_cnf)
 MESSAGE_DEF(NAS_DOWNLINK_DATA_IND,      MESSAGE_PRIORITY_MED,       NasDlDataInd,               nas_dl_data_ind)
 

openair2/COMMON/rrc_messages_types.h

@@ -82,6 +82,7 @@
 #define NAS_PAGING_IND(mSGpTR)          (mSGpTR)->ittiMsg.nas_paging_ind
 #define NAS_CONN_ESTABLI_CNF(mSGpTR)    (mSGpTR)->ittiMsg.nas_conn_establi_cnf
 #define NAS_CONN_RELEASE_IND(mSGpTR)    (mSGpTR)->ittiMsg.nas_conn_release_ind
+#define NR_NAS_CONN_RELEASE_IND(mSGpTR) (mSGpTR)->ittiMsg.nr_nas_conn_release_ind
 #define NAS_UPLINK_DATA_CNF(mSGpTR)     (mSGpTR)->ittiMsg.nas_ul_data_cnf
 #define NAS_DOWNLINK_DATA_IND(mSGpTR)   (mSGpTR)->ittiMsg.nas_dl_data_ind
 
@@ -452,6 +453,16 @@ typedef struct nrrrc_frame_process_s {
   int gnb_id;
 } NRRrcFrameProcess;
 
+typedef enum NR_Release_Cause_e {
+  RRC_CONNECTION_FAILURE,
+  RRC_RESUME_FAILURE,
+  OTHER,
+} NR_Release_Cause_t;
+
+typedef struct nr_nas_conn_release_ind {
+  NR_Release_Cause_t cause;
+} NRNasConnReleaseInd;
+
 // eNB: RLC -> RRC messages
 typedef struct rlc_sdu_indication_s {
   int rnti;

openair2/RRC/NR_UE/rrc_UE.c

@@ -1334,19 +1334,13 @@ static int nr_rrc_ue_decode_dcch(instance_t instance,
         case NR_DL_DCCH_MessageType__c1_PR_rrcResume:
           LOG_I(NR_RRC, "Received rrcResume on DL-DCCH-Message\n");
           break;
-        case NR_DL_DCCH_MessageType__c1_PR_rrcRelease: {
-          struct NR_RRCRelease__criticalExtensions *ext = &c1->choice.rrcRelease->criticalExtensions;
-          LOG_I(NR_RRC, "Received RRC Release (gNB %d)\n", gNB_indexP);
-          MessageDef *msg_p = itti_alloc_new_message(TASK_RRC_NRUE, 0, NAS_CONN_RELEASE_IND);
-          // FixMe: this code do nothing !!!!
-          if (ext->present == NR_RRCRelease__criticalExtensions_PR_rrcRelease) {
-            ext->choice.rrcRelease->deprioritisationReq->deprioritisationTimer =
-                NR_RRCRelease_IEs__deprioritisationReq__deprioritisationTimer_min5;
-            ext->choice.rrcRelease->deprioritisationReq->deprioritisationType =
-                NR_RRCRelease_IEs__deprioritisationReq__deprioritisationType_frequency;
-          }
-          itti_send_msg_to_task(TASK_NAS_NRUE, instance, msg_p);
-        } break;
+        case NR_DL_DCCH_MessageType__c1_PR_rrcRelease:
+          LOG_I(NR_RRC, "[UE %ld] Received RRC Release (gNB %d)\n",
+                instance, gNB_indexP);
+          // TODO properly implement procedures in 5.3.8.3 of 38.331
+          NR_Release_Cause_t cause = OTHER;
+          nr_rrc_going_to_IDLE(instance, cause, dl_dcch_msg->message.choice.c1->choice.rrcRelease);
+          break;
 
         case NR_DL_DCCH_MessageType__c1_PR_ueCapabilityEnquiry:
           LOG_I(NR_RRC, "Received Capability Enquiry (gNB %d)\n", gNB_indexP);
@@ -1847,6 +1841,7 @@ static void process_lte_nsa_msg(NR_UE_RRC_INST_t *rrc, nsa_msg_t *msg, int msg_l
 }
 
 void nr_rrc_going_to_IDLE(instance_t instance,
+                          NR_Release_Cause_t release_cause,
                           NR_RRCRelease_t *RRCRelease)
 {
   NR_UE_RRC_INST_t *rrc = &NR_UE_rrc_inst[instance];
@@ -1867,9 +1862,8 @@ void nr_rrc_going_to_IDLE(instance_t instance,
         // start timer T302 with the value set to the waitTime
         tac->T302_active = true;
         tac->T302_k = *waitTime * 1000; // waitTime is in seconds
-        // inform upper layers that access barring is applicable
+        // TODO inform upper layers that access barring is applicable
         // for all access categories except categories '0' and '2'.
-        // TODO no idea what that means
         LOG_E(NR_RRC,"Go to IDLE. Handling RRCRelease message including a waitTime not implemented\n");
       }
     }
@@ -1995,12 +1989,14 @@ void nr_rrc_going_to_IDLE(instance_t instance,
 
   nr_rrc_mac_config_req_release(instance);
 
-  // TODO indicate the release of the RRC connection to upper layers
-  // together with the release cause
-
   // enter RRC_IDLE
   rrc->nrRrcState = RRC_STATE_IDLE_NR;
   rrc->rnti = 0;
+
+  // Indicate the release of the RRC connection to upper layers
+  MessageDef *msg_p = itti_alloc_new_message(TASK_RRC_NRUE, 0, NR_NAS_CONN_RELEASE_IND);
+  NR_NAS_CONN_RELEASE_IND(msg_p).cause = release_cause;
+  itti_send_msg_to_task(TASK_NAS_NRUE, instance, msg_p);
 }
 
 void nr_ue_rrc_timer_trigger(int instance, int frame, int gnb_id)

openair2/RRC/NR_UE/rrc_proto.h

@@ -92,6 +92,11 @@ int8_t nr_mac_rrc_data_ind_ue(const module_id_t module_id,
 void nr_mac_rrc_sync_ind(const module_id_t module_id,
                          const frame_t frame,
                          const bool in_sync);
+
+void nr_rrc_going_to_IDLE(instance_t instance,
+                          NR_Release_Cause_t release_cause,
+                          NR_RRCRelease_t *RRCRelease);
+
 void nr_mac_rrc_ra_ind(const module_id_t mod_id, int frame, bool success);
 void nr_mac_rrc_msg3_ind(const module_id_t mod_id, int rnti);
 

openair3/NAS/NR_UE/nr_nas_msg_sim.c

@@ -1137,14 +1137,19 @@ void *nas_nrue(void *args_p)
         break;
       }
 
-      case NAS_CONN_RELEASE_IND:
-        LOG_I(NAS, "[UE %ld] Received %s: cause %u\n", instance, ITTI_MSG_NAME(msg_p), NAS_CONN_RELEASE_IND(msg_p).cause);
-        /* the following is not clean, but probably necessary: we need to give
-         * time to RLC to Ack the SRB1 PDU which contained the RRC release
-         * message. Hence, we just below wait some time, before finally
-         * unblocking the nr-uesoftmodem, which will terminate the process. */
-        usleep(100000);
-        itti_wait_tasks_unblock(); /* will unblock ITTI to stop nr-uesoftmodem */
+      case NR_NAS_CONN_RELEASE_IND:
+        LOG_I(NAS, "[UE %ld] Received %s: cause %u\n",
+              instance, ITTI_MSG_NAME (msg_p), NR_NAS_CONN_RELEASE_IND (msg_p).cause);
+        nr_ue_nas_t *nas = get_ue_nas_info(0);
+        // TODO handle connection release
+        if (nas->termination_procedure) {
+          /* the following is not clean, but probably necessary: we need to give
+           * time to RLC to Ack the SRB1 PDU which contained the RRC release
+           * message. Hence, we just below wait some time, before finally
+           * unblocking the nr-uesoftmodem, which will terminate the process. */
+          usleep(100000);
+          itti_wait_tasks_unblock(); /* will unblock ITTI to stop nr-uesoftmodem */
+        }
         break;
 
       case NAS_UPLINK_DATA_CNF:
@@ -1162,6 +1167,8 @@ void *nas_nrue(void *args_p)
         nr_ue_nas_t *nas = get_ue_nas_info(0);
         if (nas->guti) {
           nas_deregistration_req_t *req = &NAS_DEREGISTRATION_REQ(msg_p);
+          if (req->cause == AS_DETACH)
+            nas->termination_procedure = true;
           as_nas_info_t initialNasMsg = {0};
           generateDeregistrationRequest(nas, &initialNasMsg, req);
           send_nas_uplink_data_req(instance, &initialNasMsg);

openair3/NAS/NR_UE/nr_nas_msg_sim.h

@@ -98,6 +98,7 @@ typedef struct {
   uicc_t *uicc;
   ue_sa_security_key_t security;
   Guti5GSMobileIdentity_t *guti;
+  bool termination_procedure;
 } nr_ue_nas_t;
 
 typedef enum fgs_protocol_discriminator_e {