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srsLTE
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Update COUNT estimation for SRBs in PDCP

This commit is contained in:
Pedro Alvarez 2020-02-06 19:02:29 +00:00 committed by Andre Puschmann
parent 965b0ee99b
commit 6648f7ebca
1 changed files with 15 additions and 4 deletions
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19
lib/src/upper/pdcp_entity_lte.cc
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@ -174,7 +174,7 @@ void pdcp_entity_lte::write_pdu(unique_byte_buffer_t pdu)
* Ref: 3GPP TS 36.323 v10.1.0 Section 5.1.2
***************************************************************************/
// SRBs (5.1.2.2)
// Returns a boolean indicating weather integrity has passed
// Returns a boolean indicating whether integrity has passed
bool pdcp_entity_lte::handle_srb_pdu(const srslte::unique_byte_buffer_t& pdu)
{
@ -182,21 +182,32 @@ bool pdcp_entity_lte::handle_srb_pdu(const srslte::unique_byte_buffer_t& pdu)
uint8_t mac[4];
pdcp_unpack_control_pdu(pdu.get(), &sn, mac);
// TODO Fix count computation
uint32_t count = sn;
// Estimate COUNT for integrity check and decryption
uint32_t count;
if (sn < next_pdcp_rx_sn){
count = COUNT(rx_hfn + 1, sn);
} else {
count = COUNT(rx_hfn, sn);
}
// Perform integrity checks and decription
if (do_encryption) {
cipher_decrypt(pdu->msg, pdu->N_bytes, count, pdu->msg);
log->info_hex(pdu->msg, pdu->N_bytes, "RX %s PDU (decrypted)", rrc->get_rb_name(lcid).c_str());
}
if (do_integrity) {
if (not integrity_verify(pdu->msg, pdu->N_bytes - 4, sn, &(pdu->msg[pdu->N_bytes - 4]))) {
if (not integrity_verify(pdu->msg, pdu->N_bytes, count, mac)) {
log->error_hex(pdu->msg, pdu->N_bytes, "%s Dropping PDU", rrc->get_rb_name(lcid).c_str());
return false;
}
}
// Update state variables
if (sn < next_pdcp_rx_sn) {
rx_hfn++;
}
log->info_hex(pdu->msg, pdu->N_bytes, "RX %s PDU SN: %d", rrc->get_rb_name(lcid).c_str(), sn);
return true;
}