/****************************************************************************
** **
** Name: _esm_msg_decode_header() **
** **
** Description: Decode header of EPS Mobility Management message. **
** The protocol discriminator and the security header type **
** have already been decoded. **
** **
** Inputs: buffer: Pointer to the buffer containing the ESM **
** message **
** len: Number of bytes that should be decoded **
** Others: None **
** **
** Outputs: header: The ESM message header to be filled **
** Return: The size of the header if data have been **
** successfully decoded; **
** A negative error code otherwise. **
** Others: None **
** **
***************************************************************************/
static int
_esm_msg_decode_header (
esm_msg_header_t * header,
const uint8_t * buffer,
uint32_t len)
{
int size = 0;
/*
* Check the buffer length
*/
if (len < sizeof (esm_msg_header_t)) {
return (TLV_DECODE_BUFFER_TOO_SHORT);
}
/*
* Decode the EPS bearer identity and the protocol discriminator
*/
DECODE_U8 (buffer + size, *(uint8_t *) (header), size);
/*
* Decode the procedure transaction identity
*/
DECODE_U8 (buffer + size, header->procedure_transaction_identity, size);
/*
* Decode the message type
*/
DECODE_U8 (buffer + size, header->message_type, size);
/*
* Check the protocol discriminator
*/
if (header->protocol_discriminator != EPS_SESSION_MANAGEMENT_MESSAGE) {
LOG_TRACE (ERROR, "ESM-MSG - Unexpected protocol discriminator: 0x%x", header->protocol_discriminator);
return (TLV_DECODE_PROTOCOL_NOT_SUPPORTED);
}
return (size);
}
int decode_ue_network_capability(UeNetworkCapability *uenetworkcapability, uint8_t iei, uint8_t *buffer, uint32_t len)
{
int decoded = 0;
uint8_t ielen = 0;
if (iei > 0)
{
CHECK_IEI_DECODER(iei, *buffer);
decoded++;
}
DECODE_U8(buffer + decoded, ielen, decoded);
memset(uenetworkcapability, 0, sizeof(UeNetworkCapability));
LOG_TRACE(INFO, "decode_ue_network_capability len = %d",ielen);
CHECK_LENGTH_DECODER(len - decoded, ielen);
uenetworkcapability->eea = *(buffer + decoded);
decoded++;
uenetworkcapability->eia = *(buffer + decoded);
decoded++;
/* Parts below not mandatory and may not be present */
if (ielen > 2) {
uenetworkcapability->uea = *(buffer + decoded);
decoded++;
if (ielen > 3) {
uenetworkcapability->ucs2 = (*(buffer + decoded) >> 7) & 0x1;
uenetworkcapability->uia = *(buffer + decoded) & 0x7f;
decoded++;
uenetworkcapability->umts_present =1;
LOG_TRACE(INFO, "uenetworkcapability decoded UMTS\n");
if (ielen > 4) {
uenetworkcapability->spare = (*(buffer + decoded) >> 5) & 0x7;
uenetworkcapability->csfb = (*(buffer + decoded) >> 4) & 0x1;
uenetworkcapability->lpp = (*(buffer + decoded) >> 3) & 0x1;
uenetworkcapability->lcs = (*(buffer + decoded) >> 2) & 0x1;
uenetworkcapability->srvcc = (*(buffer + decoded) >> 1) & 0x1;
uenetworkcapability->nf = *(buffer + decoded) & 0x1;
decoded++;
uenetworkcapability->gprs_present =1;
LOG_TRACE(INFO, "uenetworkcapability decoded GPRS\n");
}