F1 UE Context Modif Req: Implement DRB Release

- Add necessary fields to F1 message
- Add F1AP encoding/decoding of UE Ctxt Modif Req DRB Release

openair2/COMMON/f1ap_messages_types.h

@@ -301,6 +301,10 @@ typedef struct f1ap_rb_failed_to_be_setup_s {
   long           rb_id;
 } f1ap_rb_failed_to_be_setup_t;
 
+typedef struct f1ap_drb_to_be_released_t {
+  long rb_id;
+} f1ap_drb_to_be_released_t;
+
 typedef struct cu_to_du_rrc_information_s {
   uint8_t * cG_ConfigInfo;
   uint32_t   cG_ConfigInfo_length;
@@ -354,6 +358,8 @@ typedef struct f1ap_ue_context_setup_s {
   f1ap_srb_to_be_setup_t *srbs_to_be_setup;
   uint8_t  srbs_to_be_setup_length;
   uint8_t  srbs_failed_to_be_setup_length;
+  uint8_t drbs_to_be_released_length;
+  f1ap_drb_to_be_released_t *drbs_to_be_released;
   f1ap_rb_failed_to_be_setup_t *srbs_failed_to_be_setup;
   ReconfigurationCompl_t ReconfigComplOutcome;
   uint8_t *rrc_container;

openair2/F1AP/f1ap_cu_ue_context_management.c

@@ -1531,14 +1531,14 @@ int CU_send_UE_CONTEXT_MODIFICATION_REQUEST(instance_t instance, f1ap_ue_context
   }
 
   /* optional */
-  if(0){
+  if (f1ap_ue_context_modification_req->drbs_to_be_released_length > 0) {
     /* c15. DRBs_ToBeReleased_List */
     asn1cSequenceAdd(out->protocolIEs.list, F1AP_UEContextModificationRequestIEs_t, ie15);
     ie15->id                             = F1AP_ProtocolIE_ID_id_DRBs_ToBeReleased_List;
     ie15->criticality                    = F1AP_Criticality_reject;
     ie15->value.present                  = F1AP_UEContextModificationRequestIEs__value_PR_DRBs_ToBeReleased_List;
 
-    for (int i=0; i<1;  i++) {
+    for (int i = 0; i < f1ap_ue_context_modification_req->drbs_to_be_released_length; i++) {
       //
       asn1cSequenceAdd(ie15->value.choice.DRBs_ToBeReleased_List.list,
                      F1AP_DRBs_ToBeReleased_ItemIEs_t, drbs_toBeReleased_item_ies);
@@ -1549,7 +1549,7 @@ int CU_send_UE_CONTEXT_MODIFICATION_REQUEST(instance_t instance, f1ap_ue_context
       F1AP_DRBs_ToBeReleased_Item_t *drbs_toBeReleased_item=
           &drbs_toBeReleased_item_ies->value.choice.DRBs_ToBeReleased_Item;
       /* dRBID */
-      drbs_toBeReleased_item->dRBID = 30L;
+      drbs_toBeReleased_item->dRBID = f1ap_ue_context_modification_req->drbs_to_be_released[i].rb_id;
     }
   }
 

openair2/F1AP/f1ap_du_ue_context_management.c

@@ -881,6 +881,23 @@ int DU_handle_UE_CONTEXT_MODIFICATION_REQUEST(instance_t instance, sctp_assoc_t
       }
     }
   }
+
+  F1AP_FIND_PROTOCOLIE_BY_ID(F1AP_UEContextModificationRequestIEs_t, ieDrb, container,
+                   F1AP_ProtocolIE_ID_id_DRBs_ToBeReleased_List, false);
+  if (ieDrb != NULL) {
+    f1ap_ue_context_modification_req->drbs_to_be_released_length = ieDrb->value.choice.DRBs_ToBeReleased_List.list.count;
+    f1ap_ue_context_modification_req->drbs_to_be_released =
+        calloc(f1ap_ue_context_modification_req->drbs_to_be_released_length, sizeof(f1ap_drb_to_be_released_t));
+    AssertFatal(f1ap_ue_context_modification_req->drbs_to_be_released,
+                "could not allocate memory for f1ap_ue_context_released_req->drbs_to_be_released\n");
+    for (i = 0; i < f1ap_ue_context_modification_req->drbs_to_be_released_length; ++i) {
+      F1AP_DRBs_ToBeReleased_ItemIEs_t *tbrel = (F1AP_DRBs_ToBeReleased_ItemIEs_t *)ieDrb->value.choice.DRBs_ToBeReleased_List.list.array[i];
+      DevAssert(tbrel->id == F1AP_ProtocolIE_ID_id_DRBs_ToBeReleased_Item);
+      DevAssert(tbrel->value.present == F1AP_DRBs_ToBeReleased_ItemIEs__value_PR_DRBs_ToBeReleased_Item);
+      f1ap_ue_context_modification_req->drbs_to_be_released[i].rb_id = tbrel->value.choice.DRBs_ToBeReleased_Item.dRBID;
+    }
+  }
+
   /* RRC Reconfiguration Complete indicator */
   F1AP_UEContextModificationRequestIEs_t *ieReconf;
   F1AP_FIND_PROTOCOLIE_BY_ID(F1AP_UEContextModificationRequestIEs_t, ieReconf, container,

openair2/RRC/NR/mac_rrc_dl_f1ap.c

@@ -94,6 +94,13 @@ static void ue_context_modification_request_f1ap(const f1ap_ue_context_modif_req
     AssertFatal(f1ap_msg->srbs_to_be_setup != NULL, "out of memory\n");
     memcpy(f1ap_msg->srbs_to_be_setup, req->srbs_to_be_setup, n * sizeof(*f1ap_msg->srbs_to_be_setup));
   }
+  if (req->drbs_to_be_released_length > 0) {
+    int n = req->drbs_to_be_released_length;
+    f1ap_msg->drbs_to_be_released_length = n;
+    f1ap_msg->drbs_to_be_released = calloc(n, sizeof(*f1ap_msg->drbs_to_be_released));
+    AssertFatal(f1ap_msg->drbs_to_be_released != NULL, "out of memory\n");
+    memcpy(f1ap_msg->drbs_to_be_released, req->drbs_to_be_released, n * sizeof(*f1ap_msg->drbs_to_be_released));
+  }
   if (req->rrc_container_length > 0) {
     f1ap_msg->rrc_container = calloc(req->rrc_container_length, sizeof(*f1ap_msg->rrc_container));
     AssertFatal(f1ap_msg->rrc_container != NULL, "out of memory\n");