Error in decoding of the X2AP "Handover Request" message

[sandeep2501]

Hello mouse07410

I have downloaded the latest asn1c code from your branch. I am decoding the X2AP "Handover Request" message but it is giving error in its decoding. Buffer is "00000081EF000008000A00020D6D000540020000000B00080004F413E133D010001700070004F41383F158000E0081A2660841852718000C0000F6899974B8E1CCADC61FEB2C40D6AF053F53C0914DA80831B2D221A902FF6FDF030BEBC20060017D784000000004400E4500070501F00ACEFA05803E22C681440B305CC9980070938650002074A1E3FF8DFE3FF8DFE3FF8DFE3FF8DFE3FF8DFE3FF8DFE3FF8DFE3FF8DFDFF3FFA7A204021C329D2A4A91C5FB00000001C07FCFFEBEC0000000709FF3FFA7B000000002A8008000161100100000880080000020F33035758A6601404E28810F121E5003211B93432B2596621E4000D8000378718CC43C8001B0000690CB19887900036000089500000402AB22906320108B841068D00E2101C553C0D3A81D3AE44F9C9273840050870A401025228420113DB8800004011004D6C052EE910C1E0E052EE910C9C00FA89A00A5DD22072333E8013A229AFC5D83211F0CAA20DC3205402EC0260DF99434000240A14088CCC910000205010630024E23450382350860272300448632140514185E70D85FE324E03410A20180CC020480CEDA6A20500781E6E86974C81C204060105560501204ABC0024FEC8A214004F4134004F40104F42904F51504F46104F565000F400C000004F413E23450310000000024400100FFFA400900E234503619006C39"

If I use any online tool to decode the same message, it get decode perfectly.

Can you please check, what is the problem.

Regards Sandeep

[brchiu]

@sandeep2501 , please also try this branch

https://github.com/brchiu/asn1c/tree/velichkov_s1ap_plus_option_group_plus_adding_trailing_ull

[sandeep2501]

@brchiu Same error with code branch also.

Sandeep

[brchiu]

@sandeep2501 , I use ASN.1 playground to decode it and the last Information Object is of id 65530 which is not defined in current X2AP ASN.1. And that's why asn1c verdict decoding failed.

rec1value X2AP-PDU ::= initiatingMessage : {
  procedureCode 0,
  criticality reject,
  value HandoverRequest : {
    protocolIEs {
      {
        id 10,
        criticality reject,
        value UE-X2AP-ID : 3437
      },
      {
        id 5,
        criticality ignore,
        value Cause : radioNetwork : handover-desirable-for-radio-reasons
      },
      {
        id 11,
        criticality reject,
        value ECGI : {
          pLMN-Identity '04F413'H,
          eUTRANcellIdentifier '1110000100110011110100000001'B
        }
      },
      {
        id 23,
        criticality reject,
        value GUMMEI : {
          gU-Group-ID {
            pLMN-Identity '04F413'H,
            mME-Group-ID '83F1'H
          },
          mME-Code '58'H
        }
      },
      {
        id 14,
        criticality reject,
        value UE-ContextInformation : {
          mME-UE-S1AP-ID 138511655,
          uESecurityCapabilities {
            encryptionAlgorithms '1100000000000000'B,
            integrityProtectionAlgorithms '1100000000000000'B
          },
          aS-SecurityInformation {
            key-eNodeB-star '1111011010001001100110010111010010111000111000011100110010101101110001100001111111101011001011000100000011010110101011110000010100111111010100111100000010010001010011011010100000001000001100011011001011010010001000011010100100000010111111110110111111011111'B,
            nextHopChainingCount 0
          },
          uEaggregateMaximumBitRate {
            uEaggregateMaximumBitRateDownlink 200000000,
            uEaggregateMaximumBitRateUplink 25000000
          },
          subscriberProfileIDforRFP 1,
          e-RABs-ToBeSetup-List {
            {
              id 4,
              criticality ignore,
              value E-RABs-ToBeSetup-Item : {
                e-RAB-ID 5,
                e-RAB-Level-QoS-Parameters {
                  qCI 7,
                  allocationAndRetentionPriority {
                    priorityLevel highest,
                    pre-emptionCapability shall-not-trigger-pre-emption,
                    pre-emptionVulnerability pre-emptable
                  }
                },
                dL-Forwarding dL-forwardingProposed,
                uL-GTPtunnelEndpoint {
                  transportLayerAddress '00001010110011101111101000000101'B,
                  gTP-TEID '803E22C6'H
                }
              }
            }
          },
          rRC-Context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
          handoverRestrictionList {
            servingPLMN '04F413'H,
            equivalentPLMNs {
              '04F401'H,
              '04F429'H,
              '04F515'H,
              '04F461'H,
              '04F565'H
            }
          }
        }
      },
      {
        id 15,
        criticality ignore,
        value UE-HistoryInformation : {
          e-UTRAN-Cell : {
            global-Cell-ID {
              pLMN-Identity '04F413'H,
              eUTRANcellIdentifier '1110001000110100010100000011'B
            },
            cellType {
              cell-Size medium
            },
            time-UE-StayedInCell 0
          }
        }
      },
      {
        id 36,
        criticality ignore,
        value SRVCCOperationPossible : possible
      },
      {
        id 65530,
        criticality ignore,
        value OCTET STRING : '00E234503619006C39'H
      }
    }
  }
}

[sandeep2501]

@brchiu , is there any solution to this problem Can we decode it and get the output like "ASN.1 playground".