E1AP: add DRB To Remove list to E1 Bearer Context Modification lib

Add DRB To Remove List IE to PDU Session To Modify list, which is sent
in the Bearer Context Modification request. This allows the CUCP to
inform the CUUP about DRBs to be released in a specific PDU session
during a MODIFY procedure.

Changes:

* Add struct definition
* Add enc/dec/eq/cp func
* Add test

openair2/E1AP/lib/e1ap_bearer_context_management.c

@@ -1465,6 +1465,14 @@ static E1AP_PDU_Session_Resource_To_Modify_Item_t e1_encode_pdu_session_to_mod_i
       *ie1_2 = e1_encode_qos_flow_to_setup(k);
     }
   }
+  // DRB To Remove List (O)
+  if (in->n_drb_to_remove > 0) {
+    asn1cCalloc(out.dRB_To_Remove_List_NG_RAN, drb2Remove_List);
+    for (int r = 0; r < in->n_drb_to_remove; r++) {
+      asn1cSequenceAdd(drb2Remove_List->list, E1AP_DRB_To_Remove_Item_NG_RAN_t, drb2Rem);
+      drb2Rem->dRB_ID = in->drbs_to_remove[r].id;
+    }
+  }
   return out;
 }
 
@@ -1746,6 +1754,15 @@ static bool e1_decode_pdu_session_to_mod_item(pdu_session_to_mod_t *out, const E
       }
     }
   }
+  // DRB To Remove List (O)
+  if (in->dRB_To_Remove_List_NG_RAN) {
+    E1AP_DRB_To_Remove_List_NG_RAN_t *rm = in->dRB_To_Remove_List_NG_RAN;
+    out->n_drb_to_remove = rm->list.count;
+    for (int r = 0; r < rm->list.count; r++) {
+      E1AP_DRB_To_Remove_Item_NG_RAN_t *item = rm->list.array[r];
+      out->drbs_to_remove[r].id = item->dRB_ID;
+    }
+  }
   return true;
 }
 
@@ -1931,6 +1948,9 @@ static pdu_session_to_mod_t cp_pdu_session_to_mod_item(const pdu_session_to_mod_
   // DRB to modify list
   for (int j = 0; j < msg->numDRB2Modify; j++)
     cp.DRBnGRanModList[j] = cp_drb_to_mod_item(&msg->DRBnGRanModList[j]);
+  // DRB to remove list
+  for (int r = 0; r < msg->n_drb_to_remove; r++)
+    cp.drbs_to_remove[r] = msg->drbs_to_remove[r];
   _E1_CP_OPTIONAL_IE(&cp, msg, securityIndication);
   _E1_CP_OPTIONAL_IE(&cp, msg, UP_TL_information);
   return cp;
@@ -2021,6 +2041,10 @@ static bool eq_pdu_session_to_mod_item(const pdu_session_to_mod_t *a, const pdu_
       return false;
   }
   _E1_EQ_CHECK_OPTIONAL_PTR(a, b, securityIndication);
+  _E1_EQ_CHECK_INT(a->n_drb_to_remove, b->n_drb_to_remove);
+  for (int r = 0; r < a->n_drb_to_remove; r++) {
+    _E1_EQ_CHECK_LONG(a->drbs_to_remove[r].id, b->drbs_to_remove[r].id);
+  }
   if (a->securityIndication && b->securityIndication) {
     if (!eq_security_ind(a->securityIndication, b->securityIndication))
       return false;

openair2/E1AP/lib/e1ap_lib_includes.h

@@ -76,6 +76,8 @@
 #include "E1AP_PDU-Session-Resource-To-Modify-Item.h"
 #include "E1AP_DRB-To-Modify-List-NG-RAN.h"
 #include "E1AP_DRB-To-Modify-Item-NG-RAN.h"
+#include "E1AP_DRB-To-Remove-List-NG-RAN.h"
+#include "E1AP_DRB-To-Remove-Item-NG-RAN.h"
 #include "E1AP_PDU-Session-Resource-To-Setup-Mod-Item.h"
 #include "E1AP_DRB-To-Setup-Mod-Item-NG-RAN.h"
 #include "E1AP_PDU-Session-Resource-To-Remove-Item.h"