ue,nr,mac: fix race-condition when accesing temp RNTIs during RA procedure

the race was in the prach_nr that stored the temp crnti without proper protection.
the fix moves the logic to store the value to the MAC that uses the thread-safe
RNTI object for this.
This commit is contained in:
Andre Puschmann 2022-04-19 08:51:59 +02:00
parent 87f22bb294
commit b157490cb3
6 changed files with 50 additions and 39 deletions

View File

@ -92,6 +92,8 @@ public:
uint16_t get_crnti();
uint16_t get_temp_crnti();
uint16_t get_csrnti() { return SRSRAN_INVALID_RNTI; }; // SPS not supported
void set_temp_crnti(uint16_t temp_crnti);
void set_crnti_to_temp();
/// procedure sr nr interface
void start_ra() { proc_ra.start_by_mac(); }
@ -130,6 +132,7 @@ private:
bool is_paging_opportunity();
bool has_crnti();
bool has_temp_crnti();
bool is_valid_crnti(const uint16_t crnti);
std::vector<srsran::logical_channel_config_t> logical_channels; // stores the raw configs provide by upper layers

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@ -26,6 +26,8 @@ public:
// Functions for identity handling, e.g., contention id and c-rnti
virtual uint16_t get_crnti() = 0;
virtual bool set_crnti(uint16_t c_rnti) = 0;
virtual void set_temp_crnti(uint16_t c_rnti) = 0;
virtual void set_crnti_to_temp() = 0;
// Functions for msg3 manipulation which shall be transparent to the procedure
virtual bool msg3_is_transmitted() = 0;

View File

@ -40,6 +40,7 @@ public:
uint16_t get_rar_rnti();
bool has_temp_crnti();
uint16_t get_temp_crnti();
void set_crnti_to_temp();
void received_contention_resolution(bool is_successful);
// PHY interfaces
@ -64,8 +65,6 @@ private:
int ra_window_length = -1, ra_window_start = -1;
uint16_t rar_rnti = SRSRAN_INVALID_RNTI;
uint16_t temp_crnti = SRSRAN_INVALID_RNTI;
uint16_t transmitted_crnti = SRSRAN_INVALID_RNTI;
std::mutex mutex;
srsran::rach_cfg_nr_t rach_cfg = {};

View File

@ -163,9 +163,9 @@ void mac_nr::update_buffer_states()
mac_interface_phy_nr::sched_rnti_t mac_nr::get_ul_sched_rnti_nr(const uint32_t tti)
{
if (proc_ra.has_temp_crnti() && has_crnti() == false) {
logger.debug("SCHED: Searching temp C-RNTI=0x%x (proc_ra)", proc_ra.get_temp_crnti());
return {proc_ra.get_temp_crnti(), srsran_rnti_type_c};
if (has_temp_crnti() && has_crnti() == false) {
logger.debug("SCHED: Searching temp C-RNTI=0x%x (proc_ra)", rntis.get_temp_rnti());
return {rntis.get_temp_rnti(), srsran_rnti_type_c};
}
return {rntis.get_crnti(), srsran_rnti_type_c};
}
@ -195,9 +195,9 @@ mac_interface_phy_nr::sched_rnti_t mac_nr::get_dl_sched_rnti_nr(const uint32_t t
return {proc_ra.get_rar_rnti(), srsran_rnti_type_ra};
}
if (proc_ra.has_temp_crnti() && has_crnti() == false) {
logger.debug("SCHED: Searching temp C-RNTI=0x%x (proc_ra)", proc_ra.get_temp_crnti());
return {proc_ra.get_temp_crnti(), srsran_rnti_type_c};
if (has_temp_crnti() && has_crnti() == false) {
logger.debug("SCHED: Searching temp C-RNTI=0x%x (proc_ra)", rntis.get_temp_rnti());
return {rntis.get_temp_rnti(), srsran_rnti_type_c};
}
if (has_crnti()) {
@ -209,6 +209,26 @@ mac_interface_phy_nr::sched_rnti_t mac_nr::get_dl_sched_rnti_nr(const uint32_t t
return {SRSRAN_INVALID_RNTI, srsran_rnti_type_c};
}
bool mac_nr::has_temp_crnti()
{
return rntis.get_temp_rnti() != SRSRAN_INVALID_RNTI;
}
uint16_t mac_nr::get_temp_crnti()
{
return rntis.get_temp_rnti();
}
void mac_nr::set_temp_crnti(uint16_t temp_crnti)
{
rntis.set_temp_rnti(temp_crnti);
}
void mac_nr::set_crnti_to_temp()
{
rntis.set_crnti_to_temp();
}
bool mac_nr::has_crnti()
{
return rntis.get_crnti() != SRSRAN_INVALID_RNTI;
@ -219,11 +239,6 @@ uint16_t mac_nr::get_crnti()
return rntis.get_crnti();
}
uint16_t mac_nr::get_temp_crnti()
{
return proc_ra.get_temp_crnti();
}
srsran::mac_sch_subpdu_nr::lcg_bsr_t mac_nr::generate_sbsr()
{
return proc_bsr.generate_sbsr();
@ -309,7 +324,7 @@ void mac_nr::new_grant_dl(const uint32_t cc_idx, const mac_nr_grant_dl_t& grant,
void mac_nr::tb_decoded(const uint32_t cc_idx, const mac_nr_grant_dl_t& grant, tb_action_dl_result_t result)
{
logger.debug("tb_decoded(): cc_idx=%d, tti=%d, rnti=%d, pid=%d, tbs=%d, ndi=%d, rv=%d, result=%s",
logger.debug("tb_decoded(): cc_idx=%d, tti=%d, rnti=0x%X, pid=%d, tbs=%d, ndi=%d, rv=%d, result=%s",
cc_idx,
grant.tti,
grant.rnti,
@ -336,14 +351,14 @@ void mac_nr::tb_decoded(const uint32_t cc_idx, const mac_nr_grant_dl_t& grant, t
}
// If proc ra is in contention resolution (RA connection request procedure)
if (proc_ra.is_contention_resolution() && grant.rnti == get_temp_crnti()) {
if (proc_ra.is_contention_resolution() && grant.rnti == rntis.get_temp_rnti()) {
proc_ra.received_contention_resolution(contention_res_successful);
}
}
void mac_nr::new_grant_ul(const uint32_t cc_idx, const mac_nr_grant_ul_t& grant, tb_action_ul_t* action)
{
logger.debug("new_grant_ul(): cc_idx=%d, tti=%d, rnti=%d, pid=%d, tbs=%d, ndi=%d, rv=%d, is_rar=%d",
logger.debug("new_grant_ul(): cc_idx=%d, tti=%d, rnti=0x%X, pid=%d, tbs=%d, ndi=%d, rv=%d, is_rar=%d",
cc_idx,
grant.tti,
grant.rnti,

View File

@ -115,18 +115,6 @@ bool proc_ra_nr::has_rar_rnti()
return false;
}
bool proc_ra_nr::has_temp_crnti()
{
std::lock_guard<std::mutex> lock(mutex);
return temp_crnti != SRSRAN_INVALID_RNTI;
}
uint16_t proc_ra_nr::get_temp_crnti()
{
std::lock_guard<std::mutex> lock(mutex);
return temp_crnti;
}
void proc_ra_nr::received_contention_resolution(bool is_successful)
{
std::lock_guard<std::mutex> lock(mutex);
@ -216,13 +204,10 @@ void proc_ra_nr::ra_response_reception(const mac_interface_phy_nr::tb_action_dl_
for (auto& subpdu : pdu.get_subpdus()) {
if (subpdu.has_rapid() && subpdu.get_rapid() == preamble_index) {
logger.debug("PROC RA NR: Setting UL grant and prepare Msg3");
temp_crnti = subpdu.get_temp_crnti();
// Save transmitted C-RNTI (if any)
transmitted_crnti = mac.get_crnti();
mac.set_temp_crnti(subpdu.get_temp_crnti());
// Set Temporary-C-RNTI if provided, otherwise C-RNTI is ok
phy->set_rar_grant(tb.rx_slot_idx, subpdu.get_ul_grant(), temp_crnti, srsran_rnti_type_ra);
phy->set_rar_grant(tb.rx_slot_idx, subpdu.get_ul_grant(), subpdu.get_temp_crnti(), srsran_rnti_type_ra);
// Apply TA CMD
current_ta = subpdu.get_ta();
@ -280,12 +265,17 @@ void proc_ra_nr::ra_completion()
srsran::enum_to_text(state_str_nr, (uint32_t)ra_state_t::MAX_RA_STATES, WAITING_FOR_COMPLETION));
return;
}
// Start looking for PDCCH CRNTI
if (!mac.get_crnti()) {
// promote temp RNTI to new C-RNTI
mac.set_crnti_to_temp();
mac.set_temp_crnti(SRSRAN_INVALID_RNTI);
}
srsran::console("Random Access Complete. c-rnti=0x%x, ta=%d\n", mac.get_crnti(), current_ta);
logger.info("Random Access Complete. c-rnti=0x%x, ta=%d", mac.get_crnti(), current_ta);
if (!transmitted_crnti) {
mac.set_crnti(temp_crnti);
}
temp_crnti = SRSRAN_INVALID_RNTI;
mac.rrc_ra_completed();
reset();
}
@ -293,9 +283,9 @@ void proc_ra_nr::ra_completion()
void proc_ra_nr::ra_error()
{
std::lock_guard<std::mutex> lock(mutex);
temp_crnti = SRSRAN_INVALID_RNTI;
preamble_transmission_counter++;
contention_resolution_timer.stop();
mac.set_temp_crnti(SRSRAN_INVALID_RNTI);
uint32_t backoff_wait;
bool ra_procedure_completed = false; // true = (unsuccessfully) completed, false = uncompleted
@ -389,10 +379,10 @@ void proc_ra_nr::reset()
{
state = IDLE;
started_by = initiators_t::initiators_t_NULLTYPE;
mac.set_temp_crnti(SRSRAN_INVALID_RNTI);
prach_send_timer.stop();
rar_timeout_timer.stop();
contention_resolution_timer.stop();
transmitted_crnti = SRSRAN_INVALID_RNTI;
}
} // namespace srsue

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@ -66,6 +66,8 @@ public:
crnti = c_rnti;
return true;
}
void set_temp_crnti(uint16_t c_rnti) {}
void set_crnti_to_temp() {}
bool msg3_is_transmitted() { return true; }
void msg3_flush() {}