text: /*
   * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The OpenAirInterface Software Alliance licenses this file to You under
   * the terms found in the LICENSE file in the root of this source tree.
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *-------------------------------------------------------------------------------
   * For more information about the OpenAirInterface (OAI) Software Alliance:
   *      contact@openairinterface.org
   */
  
  #include <stdint.h>
  
  #include "lte/gateway/c/core/oai/common/TLVEncoder.h"
  #include "lte/gateway/c/core/oai/common/TLVDecoder.h"
  #include "lte/gateway/c/core/oai/tasks/nas/emm/msg/NASSecurityModeComplete.h"
  #include "lte/gateway/c/core/oai/lib/3gpp/3gpp_24.008.h"
  #include "lte/gateway/c/core/oai/common/common_defs.h"
  
  int decode_security_mode_complete(
      security_mode_complete_msg* security_mode_complete, uint8_t* buffer,
      uint32_t len) {
    uint32_t decoded = 0;
    int decoded_result = 0;
  
    // Check if we got a NULL pointer and if buffer length is >= minimum length
    // expected for the message.
    CHECK_PDU_POINTER_AND_LENGTH_DECODER(
        buffer, SECURITY_MODE_COMPLETE_MINIMUM_LENGTH, len);
  
    /*
     * Decoding mandatory fields
     */
    /*
     * Decoding optional fields
     */
    while (len > decoded) {
      uint8_t ieiDecoded = *(buffer + decoded);
  
      /*
       * Type | value iei are below 0x80 so just return the first 4 bits
       */
      if (ieiDecoded >= 0x80) ieiDecoded = ieiDecoded & 0xf0;
  
      switch (ieiDecoded) {
        case SECURITY_MODE_COMPLETE_IMEISV_IEI:
          if ((decoded_result = decode_mobile_identity_ie(
                   &security_mode_complete->imeisv,
                   SECURITY_MODE_COMPLETE_IMEISV_IEI, buffer + decoded,
                   len - decoded)) <= 0)
            return decoded_result;
  
          decoded += decoded_result;
          /*
           * Set corresponding mask to 1 in presencemask
           */
          security_mode_complete->presencemask |=
              SECURITY_MODE_COMPLETE_IMEISV_PRESENT;
          break;
  
        default:
          errorCodeDecoder = TLV_UNEXPECTED_IEI;
          return TLV_UNEXPECTED_IEI;
      }
    }
  
    return decoded;
  }
  
  int encode_security_mode_complete(
      security_mode_complete_msg* security_mode_complete, uint8_t* buffer,
      uint32_t len) {
    int encoded = 0;
    int encode_result = 0;
  
    /*
     * Checking IEI and pointer
     */
    CHECK_PDU_POINTER_AND_LENGTH_ENCODER(
        buffer, SECURITY_MODE_COMPLETE_MINIMUM_LENGTH, len);
  
    if ((security_mode_complete->presencemask &
         SECURITY_MODE_COMPLETE_IMEISV_PRESENT) ==
        SECURITY_MODE_COMPLETE_IMEISV_PRESENT) {
      if ((encode_result = encode_mobile_identity_ie(
               &security_mode_complete->imeisv, SECURITY_MODE_COMPLETE_IMEISV_IEI,
               buffer + encoded, len - encoded)) < 0)
        // Return in case of error
        return encode_result;
      else
        encoded += encode_result;
    }
  
    return encoded;
  }
  