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srsRAN/srsue/src/stack/upper/nas.cc

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/*
* Copyright 2013-2020 Software Radio Systems Limited
*
* This file is part of srsLTE.
*
* srsLTE is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* srsLTE is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* A copy of the GNU Affero General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
*
*/
#include "srsue/hdr/stack/upper/nas.h"
#include "srslte/common/bcd_helpers.h"
#include "srslte/common/security.h"
#include "srslte/common/string_helpers.h"
#include <fstream>
#include <iomanip>
#include <iostream>
#include <srslte/asn1/liblte_mme.h>
#include <sstream>
#include <unistd.h>
#include "srslte/asn1/liblte_mme.h"
#include "srslte/common/bcd_helpers.h"
#include "srslte/common/logmap.h"
#include "srslte/common/security.h"
#include "srsue/hdr/stack/upper/nas.h"
using namespace srslte;
#define ProcError(fmt, ...) nas_ptr->nas_log->error("Proc \"%s\" - " fmt, name(), ##__VA_ARGS__)
#define ProcWarning(fmt, ...) nas_ptr->nas_log->warning("Proc \"%s\" - " fmt, name(), ##__VA_ARGS__)
#define ProcInfo(fmt, ...) nas_ptr->nas_log->info("Proc \"%s\" - " fmt, name(), ##__VA_ARGS__)
namespace srsue {
using srslte::proc_outcome_t;
proc_outcome_t nas::plmn_search_proc::init()
{
// start RRC
state = state_t::plmn_search;
if (not nas_ptr->rrc->plmn_search()) {
ProcError("ProcError while searching for PLMNs\n");
return proc_outcome_t::error;
}
ProcInfo("Starting...\n");
return proc_outcome_t::yield;
}
proc_outcome_t nas::plmn_search_proc::step()
{
return proc_outcome_t::yield;
}
void nas::plmn_search_proc::then(const srslte::proc_state_t& result)
{
ProcInfo("Completed with %s\n", result.is_success() ? "success" : "failure");
if (result.is_error()) {
nas_ptr->enter_emm_deregistered();
}
}
proc_outcome_t nas::plmn_search_proc::react(const rrc_connect_proc::rrc_connect_complete_ev& t)
{
if (state != state_t::rrc_connect) {
// not expecting a rrc connection result
ProcWarning("Received unexpected RRC Connection Result event\n");
return proc_outcome_t::yield;
}
return t.is_success() ? proc_outcome_t::success : proc_outcome_t::error;
}
proc_outcome_t nas::plmn_search_proc::react(const plmn_search_complete_t& t)
{
if (state != state_t::plmn_search) {
ProcWarning("PLMN Search Complete was received but PLMN Search is not running.\n");
return proc_outcome_t::yield; // ignore
}
// check whether the state hasn't changed
if (nas_ptr->state != EMM_STATE_DEREGISTERED or nas_ptr->plmn_is_selected) {
ProcError("ProcError while searching for PLMNs\n");
return proc_outcome_t::error;
}
if (t.nof_plmns < 0) {
ProcError("Error while searching for PLMNs\n");
return proc_outcome_t::error;
}
if (t.nof_plmns == 0) {
ProcWarning("Did not find any PLMN in the set of frequencies.\n");
return proc_outcome_t::error;
}
// Save PLMNs
nas_ptr->known_plmns.clear();
for (int i = 0; i < t.nof_plmns; i++) {
nas_ptr->known_plmns.push_back(t.found_plmns[i].plmn_id);
nas_ptr->nas_log->info(
"Found PLMN: Id=%s, TAC=%d\n", t.found_plmns[i].plmn_id.to_string().c_str(), t.found_plmns[i].tac);
srslte::console(
"Found PLMN: Id=%s, TAC=%d\n", t.found_plmns[i].plmn_id.to_string().c_str(), t.found_plmns[i].tac);
}
nas_ptr->select_plmn();
// Select PLMN in request establishment of RRC connection
if (not nas_ptr->plmn_is_selected) {
ProcError("PLMN is not selected because no suitable PLMN was found\n");
return proc_outcome_t::error;
}
nas_ptr->rrc->plmn_select(nas_ptr->current_plmn);
state = state_t::rrc_connect;
if (not nas_ptr->rrc_connector.launch(srslte::establishment_cause_t::mo_sig, nullptr)) {
ProcError("Unable to initiate RRC connection.\n");
return proc_outcome_t::error;
}
nas_ptr->callbacks.add_proc(nas_ptr->rrc_connector);
return proc_outcome_t::yield;
}
nas::rrc_connect_proc::rrc_connect_proc(nas* nas_ptr_) : nas_ptr(nas_ptr_)
{
timeout_timer = nas_ptr->task_sched.get_unique_timer();
timeout_timer.set(attach_timeout_ms,
[this](uint32_t tid) { nas_ptr->rrc_connector.trigger(nas::rrc_connect_proc::attach_timeout{}); });
}
proc_outcome_t nas::rrc_connect_proc::init(srslte::establishment_cause_t cause_, srslte::unique_byte_buffer_t pdu)
{
if (nas_ptr->rrc->is_connected()) {
ProcInfo("Stopping. Reason: Already connected\n");
return proc_outcome_t::success;
}
if (pdu == nullptr) {
// Generate service request or attach request message
pdu = srslte::allocate_unique_buffer(*nas_ptr->pool, true);
if (!pdu) {
ProcError("Fatal Error: Couldn't allocate PDU.\n");
return proc_outcome_t::error;
}
if (nas_ptr->state == EMM_STATE_REGISTERED) {
nas_ptr->gen_service_request(pdu);
} else {
nas_ptr->gen_attach_request(pdu);
}
}
// Provide UE-Identity to RRC if have one
if (nas_ptr->have_guti) {
srslte::s_tmsi_t s_tmsi;
s_tmsi.mmec = nas_ptr->ctxt.guti.mme_code;
s_tmsi.m_tmsi = nas_ptr->ctxt.guti.m_tmsi;
nas_ptr->rrc->set_ue_identity(s_tmsi);
}
ProcInfo("Starting...\n");
state = state_t::conn_req;
if (not nas_ptr->rrc->connection_request(cause_, std::move(pdu))) {
ProcError("Failed to initiate a connection request procedure\n");
return proc_outcome_t::error;
}
return proc_outcome_t::yield;
}
proc_outcome_t nas::rrc_connect_proc::step()
{
if (state != state_t::wait_attach) {
return proc_outcome_t::yield;
}
// Wait until attachment. If doing a service request is already attached
if (not nas_ptr->running) {
ProcError("NAS stopped running\n");
return proc_outcome_t::error;
} else if (not nas_ptr->rrc->is_connected()) {
ProcError("Was disconnected while attaching\n");
return proc_outcome_t::error;
} else if (nas_ptr->state == EMM_STATE_REGISTERED) {
ProcInfo("Success: EMM Registered correctly.\n");
return proc_outcome_t::success;
}
// still expecting attach finish
return proc_outcome_t::yield;
}
srslte::proc_outcome_t nas::rrc_connect_proc::react(attach_timeout event)
{
if (state != state_t::wait_attach) {
return proc_outcome_t::yield;
}
if (nas_ptr->state == EMM_STATE_DEREGISTERED) {
ProcError("Timeout or received attach reject while trying to attach\n");
}
return proc_outcome_t::error;
}
void nas::rrc_connect_proc::then(const srslte::proc_state_t& result)
{
timeout_timer.stop();
nas_ptr->plmn_searcher.trigger(result);
}
proc_outcome_t nas::rrc_connect_proc::react(nas::rrc_connect_proc::connection_request_completed_t event)
{
if (state == state_t::conn_req and event.outcome) {
ProcInfo("Connection established correctly. Waiting for Attach\n");
// Wait until attachment. If doing a service request is already attached
state = state_t::wait_attach;
timeout_timer.run();
return proc_outcome_t::yield;
} else {
ProcError("Could not establish RRC connection\n");
return proc_outcome_t::error;
}
}
/*********************************************************************
* NAS
********************************************************************/
nas_base::nas_base(srslte::task_sched_handle task_sched_, const char *log_name_) :
pool(byte_buffer_pool::get_instance()),
task_sched(task_sched_),
nas_log{log_name_}
{}
nas::nas(srslte::task_sched_handle task_sched_, const nas_args_t& cfg_) :
nas_base::nas_base(task_sched_, "NAS"),
cfg(cfg_),
plmn_searcher(this),
rrc_connector(this),
t3402(task_sched_.get_unique_timer()),
t3410(task_sched_.get_unique_timer()),
t3411(task_sched_.get_unique_timer()),
t3421(task_sched_.get_unique_timer()),
reattach_timer(task_sched_.get_unique_timer())
{}
void nas::init(usim_interface_nas* usim_, rrc_interface_nas* rrc_, gw_interface_nas* gw_)
{
usim = usim_;
rrc = rrc_;
gw = gw_;
enter_state(EMM_STATE_DEREGISTERED);
if (!usim->get_home_plmn_id(&home_plmn)) {
nas_log->error("Getting Home PLMN Id from USIM. Defaulting to 001-01\n");
home_plmn.from_number(61441, 65281); // This is 001 01
}
// parse and sanity check EIA list
std::vector<uint8_t> cap_list;
srslte::string_parse_list(cfg.eia, ',', cap_list);
if (cap_list.empty()) {
nas_log->error("Empty EIA list. Select at least one EIA algorithm.\n");
}
for (std::vector<uint8_t>::const_iterator it = cap_list.begin(); it != cap_list.end(); ++it) {
if (*it != 0 && *it < 4) {
eia_caps[*it] = true;
} else {
nas_log->error("EIA%d is not a valid EIA algorithm.\n", *it);
}
}
// parse and sanity check EEA list
srslte::string_parse_list(cfg.eea, ',', cap_list);
if (cap_list.empty()) {
nas_log->error("Empty EEA list. Select at least one EEA algorithm.\n");
}
for (std::vector<uint8_t>::const_iterator it = cap_list.begin(); it != cap_list.end(); ++it) {
if (*it < 4) {
eea_caps[*it] = true;
} else {
nas_log->error("EEA%d is not a valid EEA algorithm.\n", *it);
}
}
if ((read_ctxt_file(&ctxt))) {
usim->generate_nas_keys(ctxt.k_asme, k_nas_enc, k_nas_int, ctxt.cipher_algo, ctxt.integ_algo);
nas_log->debug_hex(k_nas_enc, 32, "NAS encryption key - k_nas_enc");
nas_log->debug_hex(k_nas_int, 32, "NAS integrity key - k_nas_int");
}
// Configure timers
t3402.set(t3402_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
t3410.set(t3410_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
t3411.set(t3411_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
t3421.set(t3421_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
reattach_timer.set(reattach_timer_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
handle_airplane_mode_sim();
running = true;
}
void nas::stop()
{
running = false;
write_ctxt_file(ctxt);
}
void nas::get_metrics(nas_metrics_t* m)
{
nas_metrics_t metrics = {};
metrics.state = state;
metrics.nof_active_eps_bearer = eps_bearer.size();
*m = metrics;
}
emm_state_t nas::get_state()
{
return state;
}
void nas_base::run_tti()
{
callbacks.run();
}
void nas::timer_expired(uint32_t timeout_id)
{
if (timeout_id == t3402.id()) {
nas_log->info("Timer T3402 expired: trying to attach again\n");
attach_attempt_counter = 0; // Sec. 5.5.1.1
start_attach_proc(nullptr, srslte::establishment_cause_t::mo_sig);
} else if (timeout_id == t3410.id()) {
// Section 5.5.1.2.6 case c)
attach_attempt_counter++;
srslte::console("Attach failed (attempt %d/%d)\n", attach_attempt_counter, max_attach_attempts);
if (attach_attempt_counter < max_attach_attempts) {
nas_log->info("Timer T3410 expired after attach attempt %d/%d: starting T3411\n",
attach_attempt_counter,
max_attach_attempts);
// start T3411, ToDo: EMM-DEREGISTERED.ATTEMPTING-TO-ATTACH isn't fully implemented yet
t3411.run();
} else {
// maximum attach attempts reached
nas_log->info("Timer T3410 expired. Maximum attempts reached. Starting T3402\n");
t3402.run();
reset_security_context();
}
} else if (timeout_id == t3411.id()) {
nas_log->info("Timer T3411 expired: trying to attach again\n");
if (rrc->is_connected()) {
// send attach request through established RRC connection
send_attach_request();
} else {
// start attach procedure
start_attach_proc(nullptr, srslte::establishment_cause_t::mo_sig);
}
} else if (timeout_id == t3421.id()) {
nas_log->info("Timer T3421 expired: entering EMM_STATE_DEREGISTERED\n");
// TODO: TS 24.301 says to resend detach request but doesn't say how often before entering EMM_STATE_DEREGISTERED
// In order to allow reattaching the UE, we switch into EMM_STATE_DEREGISTERED straight
enter_emm_deregistered();
} else if (timeout_id == reattach_timer.id()) {
nas_log->info("Reattach timer expired: trying to attach again\n");
start_attach_proc(nullptr, srslte::establishment_cause_t::mo_sig);
} else {
nas_log->error("Timeout from unknown timer id %d\n", timeout_id);
}
}
/*******************************************************************************
* UE interface
******************************************************************************/
/** Blocking function to Attach to the network and establish RRC connection if not established.
* The function returns true if the UE could attach correctly or false in case of error or timeout during attachment.
*
*/
void nas::start_attach_proc(srslte::proc_state_t* result, srslte::establishment_cause_t cause_)
{
nas_log->info("Attach Request with cause %s.\n", to_string(cause_).c_str());
switch (state) {
case EMM_STATE_DEREGISTERED:
// Search PLMN is not selected
if (!plmn_is_selected) {
nas_log->info("No PLMN selected. Starting PLMN Search...\n");
if (not plmn_searcher.launch()) {
if (result != nullptr) {
result->set_error();
}
return;
}
plmn_searcher.then([this, result, cause_](const proc_state_t& res) {
nas_log->info("Attach Request from PLMN Search %s\n", res.is_success() ? "finished successfully" : "failed");
if (result != nullptr) {
*result = res;
}
if (!res.is_success()) {
// try again ..
task_sched.defer_callback(reattach_timer_duration_ms, [&]() { start_attach_proc(nullptr, cause_); });
}
});
} else {
nas_log->info("PLMN selected in state %s\n", emm_state_text[state]);
if (not rrc_connector.launch(cause_, nullptr)) {
nas_log->error("Cannot initiate concurrent rrc connection procedures\n");
if (result != nullptr) {
result->set_error();
}
return;
}
rrc_connector.then([this, result](const proc_state_t& res) {
if (res.is_success()) {
nas_log->info("NAS attached successfully\n");
} else {
nas_log->error("Could not attach from attach_request\n");
}
if (result != nullptr) {
*result = res;
}
});
callbacks.add_proc(rrc_connector);
}
break;
case EMM_STATE_REGISTERED:
if (rrc->is_connected()) {
nas_log->info("NAS is already registered and RRC connected\n");
if (result != nullptr) {
result->set_val();
}
} else {
nas_log->info("NAS is already registered but RRC disconnected. Connecting now...\n");
if (not rrc_connector.launch(cause_, nullptr)) {
nas_log->error("Cannot initiate concurrent rrc connection procedures\n");
if (result != nullptr) {
result->set_error();
}
return;
}
rrc_connector.then([this, result](const proc_state_t& res) {
if (res.is_success()) {
nas_log->info("NAS attached successfully\n");
} else {
nas_log->error("Could not attach from attach_request\n");
}
if (result != nullptr) {
*result = res;
}
});
callbacks.add_proc(rrc_connector);
}
break;
default:
nas_log->info("Attach request ignored. State = %s\n", emm_state_text[state]);
if (result != nullptr) {
result->set_error();
}
}
}
void nas::plmn_search_completed(const rrc_interface_nas::found_plmn_t found_plmns[rrc_interface_nas::MAX_FOUND_PLMNS],
int nof_plmns)
{
plmn_searcher.trigger(plmn_search_proc::plmn_search_complete_t(found_plmns, nof_plmns));
}
bool nas::detach_request(const bool switch_off)
{
switch (state) {
case EMM_STATE_REGISTERED:
// send detach request
send_detach_request(switch_off);
break;
case EMM_STATE_DEREGISTERED:
case EMM_STATE_DEREGISTERED_INITIATED:
default:
nas_log->debug("Received request to detach in state %s\n", emm_state_text[state]);
break;
}
return false;
}
void nas::enter_emm_deregistered()
{
// Deactivate EPS bearer according to Sec. 5.5.2.2.2
nas_log->debug("Clearing EPS bearer context\n");
eps_bearer.clear();
plmn_is_selected = false;
enter_state(EMM_STATE_DEREGISTERED);
}
void nas::enter_state(emm_state_t state_)
{
state = state_;
nas_log->info("New state %s\n", emm_state_text[state]);
}
void nas::left_rrc_connected() {}
bool nas::is_attached()
{
return state == EMM_STATE_REGISTERED;
}
bool nas::paging(s_tmsi_t* ue_identity)
{
if (state == EMM_STATE_REGISTERED) {
nas_log->info("Received paging: requesting RRC connection establishment\n");
if (not rrc_connector.launch(srslte::establishment_cause_t::mt_access, nullptr)) {
nas_log->error("Could not launch RRC Connect()\n");
return false;
}
// once completed, call paging complete
rrc_connector.then([this](proc_state_t outcome) { rrc->paging_completed(outcome.is_success()); });
callbacks.add_proc(rrc_connector);
} else {
nas_log->warning("Received paging while in state %s\n", emm_state_text[state]);
return false;
}
return true;
}
void nas::set_barring(barring_t barring)
{
current_barring = barring;
}
// Signal from RRC that connection request proc completed
bool nas::connection_request_completed(bool outcome)
{
rrc_connector.trigger(rrc_connect_proc::connection_request_completed_t{outcome});
return true;
}
void nas::select_plmn()
{
plmn_is_selected = false;
// First find if Home PLMN is available
for (const srslte::plmn_id_t& known_plmn : known_plmns) {
if (known_plmn == home_plmn) {
nas_log->info("Selecting Home PLMN Id=%s\n", known_plmn.to_string().c_str());
plmn_is_selected = true;
current_plmn = known_plmn;
return;
}
}
// If not, select the first available PLMN
if (not known_plmns.empty()) {
nas_log->info("Could not find Home PLMN Id=%s, trying to connect to PLMN Id=%s\n",
home_plmn.to_string().c_str(),
known_plmns[0].to_string().c_str());
srslte::console("Could not find Home PLMN Id=%s, trying to connect to PLMN Id=%s\n",
home_plmn.to_string().c_str(),
known_plmns[0].to_string().c_str());
plmn_is_selected = true;
current_plmn = known_plmns[0];
}
// reset attach attempt counter (Sec. 5.2.2.3.4)
if (plmn_is_selected) {
attach_attempt_counter = 0;
}
}
void nas::write_pdu(uint32_t lcid, unique_byte_buffer_t pdu)
{
uint8 pd = 0;
uint8 msg_type = 0;
uint8 sec_hdr_type = 0;
nas_log->info_hex(pdu->msg, pdu->N_bytes, "DL %s PDU", rrc->get_rb_name(lcid).c_str());
// Parse the message security header
liblte_mme_parse_msg_sec_header((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &pd, &sec_hdr_type);
switch (sec_hdr_type) {
case LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS:
case LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_WITH_NEW_EPS_SECURITY_CONTEXT:
case LIBLTE_MME_SECURITY_HDR_TYPE_SERVICE_REQUEST:
break;
case LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY:
case LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED:
if ((integrity_check(pdu.get()))) {
if (sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED) {
cipher_decrypt(pdu.get());
}
break;
} else {
nas_log->error("Not handling NAS message with integrity check error\n");
return;
}
case LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED_WITH_NEW_EPS_SECURITY_CONTEXT:
break;
default:
nas_log->error("Not handling NAS message with SEC_HDR_TYPE=%02X\n", sec_hdr_type);
return;
}
// Write NAS pcap
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
// Parse the message header
liblte_mme_parse_msg_header((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &pd, &msg_type);
nas_log->info_hex(pdu->msg, pdu->N_bytes, "DL %s Decrypted PDU", rrc->get_rb_name(lcid).c_str());
// drop messages if integrity protection isn't applied (see TS 24.301 Sec. 4.4.4.2)
if (sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS) {
switch (msg_type) {
case LIBLTE_MME_MSG_TYPE_IDENTITY_REQUEST: // special case for IMSI is checked in parse_identity_request()
case LIBLTE_MME_MSG_TYPE_EMM_INFORMATION:
case LIBLTE_MME_MSG_TYPE_EMM_STATUS:
case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_REQUEST:
case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_REJECT:
case LIBLTE_MME_MSG_TYPE_ATTACH_REJECT:
case LIBLTE_MME_MSG_TYPE_DETACH_REQUEST:
case LIBLTE_MME_MSG_TYPE_DETACH_ACCEPT:
case LIBLTE_MME_MSG_TYPE_TRACKING_AREA_UPDATE_REJECT:
case LIBLTE_MME_MSG_TYPE_SERVICE_REJECT:
break;
default:
nas_log->error("Not handling NAS message MSG_TYPE=%02X with SEC_HDR_TYPE=%02X without integrity protection!\n",
msg_type,
sec_hdr_type);
return;
}
}
// Reserved for Security Mode Command (Sec 9.3.1)
if (sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_WITH_NEW_EPS_SECURITY_CONTEXT &&
msg_type != LIBLTE_MME_MSG_TYPE_SECURITY_MODE_COMMAND) {
nas_log->error("Not handling NAS message MSG_TYPE=%02X with SEC_HDR_TYPE=%02X. Security header type reserved!\n",
msg_type,
sec_hdr_type);
return;
}
switch (msg_type) {
case LIBLTE_MME_MSG_TYPE_ATTACH_ACCEPT:
parse_attach_accept(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_ATTACH_REJECT:
parse_attach_reject(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_REQUEST:
parse_authentication_request(lcid, std::move(pdu), sec_hdr_type);
break;
case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_REJECT:
parse_authentication_reject(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_IDENTITY_REQUEST:
parse_identity_request(std::move(pdu), sec_hdr_type);
break;
case LIBLTE_MME_MSG_TYPE_SECURITY_MODE_COMMAND:
parse_security_mode_command(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_SERVICE_REJECT:
parse_service_reject(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_ESM_INFORMATION_REQUEST:
parse_esm_information_request(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_EMM_INFORMATION:
parse_emm_information(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_EMM_STATUS:
parse_emm_status(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_DETACH_REQUEST:
parse_detach_request(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_REQUEST:
parse_activate_dedicated_eps_bearer_context_request(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_DEACTIVATE_EPS_BEARER_CONTEXT_REQUEST:
parse_deactivate_eps_bearer_context_request(std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_MODIFY_EPS_BEARER_CONTEXT_REQUEST:
parse_modify_eps_bearer_context_request(std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_ACTIVATE_TEST_MODE:
parse_activate_test_mode(lcid, std::move(pdu));
break;
case LIBLTE_MME_MSG_TYPE_CLOSE_UE_TEST_LOOP:
parse_close_ue_test_loop(lcid, std::move(pdu));
break;
// TODO: Handle deactivate test mode and ue open test loop
case LIBLTE_MME_MSG_TYPE_OPEN_UE_TEST_LOOP:
case LIBLTE_MME_MSG_TYPE_DEACTIVATE_TEST_MODE:
gw->set_test_loop_mode(gw_interface_nas::TEST_LOOP_INACTIVE);
break;
default:
nas_log->error("Not handling NAS message with MSG_TYPE=%02X\n", msg_type);
return;
}
}
void nas_base::set_k_enb_count(uint32_t count)
{
// UL count for RRC key derivation depends on UL Count of the Attach Request or Service Request.
// On the case of an Authentication Request, the UL count used to generate K_enb must be reset to zero.
ctxt.k_enb_count = count;
}
uint32_t nas_base::get_k_enb_count()
{
return ctxt.k_enb_count;
}
bool nas::get_k_asme(uint8_t* k_asme_, uint32_t n)
{
if (!have_ctxt) {
nas_log->error("K_asme requested before security context established\n");
return false;
}
if (nullptr == k_asme_ || n < 32) {
nas_log->error("Invalid parameters to get_k_asme");
return false;
}
memcpy(k_asme_, ctxt.k_asme, 32);
return true;
}
uint32_t nas::get_ipv4_addr()
{
return ip_addr;
}
bool nas::get_ipv6_addr(uint8_t* ipv6_addr)
{
uint8_t null_addr[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
if (memcmp(ipv6_addr, null_addr, 8) != 0) {
memcpy(ipv6_addr, ipv6_if_id, 8);
return true;
}
return false;
}
/*******************************************************************************
PCAP
*******************************************************************************/
void nas_base::start_pcap(srslte::nas_pcap* pcap_)
{
pcap = pcap_;
}
/*******************************************************************************
* Security
******************************************************************************/
void nas_base::integrity_generate(uint8_t* key_128,
uint32_t count,
uint8_t direction,
uint8_t* msg,
uint32_t msg_len,
uint8_t* mac)
{
switch (ctxt.integ_algo) {
case INTEGRITY_ALGORITHM_ID_EIA0:
break;
case INTEGRITY_ALGORITHM_ID_128_EIA1:
security_128_eia1(key_128,
count,
0, // Bearer always 0 for NAS
direction,
msg,
msg_len,
mac);
break;
case INTEGRITY_ALGORITHM_ID_128_EIA2:
security_128_eia2(key_128,
count,
0, // Bearer always 0 for NAS
direction,
msg,
msg_len,
mac);
break;
case INTEGRITY_ALGORITHM_ID_128_EIA3:
security_128_eia3(key_128,
count,
0, // Bearer always 0 for NAS
direction,
msg,
msg_len,
mac);
break;
default:
break;
}
}
// This function depends to a valid k_nas_int.
// This key is generated in the security mode command.
bool nas_base::integrity_check(byte_buffer_t* pdu)
{
if (pdu == nullptr) {
nas_log->error("Invalid PDU\n");
return false;
}
if (pdu->N_bytes > 5) {
uint8_t exp_mac[4] = {0};
uint8_t* mac = &pdu->msg[1];
// generate expected MAC
uint32_t count_est = (ctxt.rx_count & 0x00FFFF00u) | pdu->msg[5];
integrity_generate(
&k_nas_int[16], count_est, SECURITY_DIRECTION_DOWNLINK, &pdu->msg[5], pdu->N_bytes - 5, &exp_mac[0]);
// Check if expected mac equals the sent mac
for (int i = 0; i < 4; i++) {
if (exp_mac[i] != mac[i]) {
nas_log->warning("Integrity check failure. Local: count=%d, [%02x %02x %02x %02x], "
"Received: count=%d, [%02x %02x %02x %02x]\n",
count_est,
exp_mac[0],
exp_mac[1],
exp_mac[2],
exp_mac[3],
pdu->msg[5],
mac[0],
mac[1],
mac[2],
mac[3]);
return false;
}
}
nas_log->info("Integrity check ok. Local: count=%d, Received: count=%d [%02x %02x %02x %02x]\n",
count_est,
pdu->msg[5],
mac[0],
mac[1],
mac[2],
mac[3]);
// Updated local count (according to TS 24.301 Sec. 4.4.3.3)
if (pdu->msg[5] != ctxt.rx_count) {
nas_log->info("Update local count to received value %d\n", pdu->msg[5]);
ctxt.rx_count = count_est;
}
return true;
} else {
nas_log->error("Invalid integrity check PDU size (%d)\n", pdu->N_bytes);
return false;
}
}
void nas_base::cipher_encrypt(byte_buffer_t* pdu)
{
byte_buffer_t pdu_tmp;
switch (ctxt.cipher_algo) {
case CIPHERING_ALGORITHM_ID_EEA0:
break;
case CIPHERING_ALGORITHM_ID_128_EEA1:
security_128_eea1(&k_nas_enc[16],
pdu->msg[5],
0, // Bearer always 0 for NAS
SECURITY_DIRECTION_UPLINK,
&pdu->msg[6],
pdu->N_bytes - 6,
&pdu_tmp.msg[6]);
memcpy(&pdu->msg[6], &pdu_tmp.msg[6], pdu->N_bytes - 6);
break;
case CIPHERING_ALGORITHM_ID_128_EEA2:
security_128_eea2(&k_nas_enc[16],
pdu->msg[5],
0, // Bearer always 0 for NAS
SECURITY_DIRECTION_UPLINK,
&pdu->msg[6],
pdu->N_bytes - 6,
&pdu_tmp.msg[6]);
memcpy(&pdu->msg[6], &pdu_tmp.msg[6], pdu->N_bytes - 6);
break;
case CIPHERING_ALGORITHM_ID_128_EEA3:
security_128_eea3(&k_nas_enc[16],
pdu->msg[5],
0, // Bearer always 0 for NAS
SECURITY_DIRECTION_UPLINK,
&pdu->msg[6],
pdu->N_bytes - 6,
&pdu_tmp.msg[6]);
memcpy(&pdu->msg[6], &pdu_tmp.msg[6], pdu->N_bytes - 6);
break;
default:
nas_log->error("Ciphering algorithm not known\n");
break;
}
}
void nas_base::cipher_decrypt(byte_buffer_t* pdu)
{
byte_buffer_t tmp_pdu;
switch (ctxt.cipher_algo) {
case CIPHERING_ALGORITHM_ID_EEA0:
break;
case CIPHERING_ALGORITHM_ID_128_EEA1:
security_128_eea1(&k_nas_enc[16],
pdu->msg[5],
0, // Bearer always 0 for NAS
SECURITY_DIRECTION_DOWNLINK,
&pdu->msg[6],
pdu->N_bytes - 6,
&tmp_pdu.msg[6]);
memcpy(&pdu->msg[6], &tmp_pdu.msg[6], pdu->N_bytes - 6);
break;
case CIPHERING_ALGORITHM_ID_128_EEA2:
security_128_eea2(&k_nas_enc[16],
pdu->msg[5],
0, // Bearer always 0 for NAS
SECURITY_DIRECTION_DOWNLINK,
&pdu->msg[6],
pdu->N_bytes - 6,
&tmp_pdu.msg[6]);
nas_log->debug_hex(tmp_pdu.msg, pdu->N_bytes, "Decrypted");
memcpy(&pdu->msg[6], &tmp_pdu.msg[6], pdu->N_bytes - 6);
break;
case CIPHERING_ALGORITHM_ID_128_EEA3:
security_128_eea3(&k_nas_enc[16],
pdu->msg[5],
0, // Bearer always 0 for NAS
SECURITY_DIRECTION_DOWNLINK,
&pdu->msg[6],
pdu->N_bytes - 6,
&tmp_pdu.msg[6]);
nas_log->debug_hex(tmp_pdu.msg, pdu->N_bytes, "Decrypted");
memcpy(&pdu->msg[6], &tmp_pdu.msg[6], pdu->N_bytes - 6);
break;
default:
nas_log->error("Ciphering algorithms not known\n");
break;
}
}
bool nas::check_cap_replay(LIBLTE_MME_UE_SECURITY_CAPABILITIES_STRUCT* caps)
{
for (uint32_t i = 0; i < 8; i++) {
if (caps->eea[i] != eea_caps[i] || caps->eia[i] != eia_caps[i]) {
return false;
}
}
return true;
}
/**
* Applies the current security config on a packed NAS PDU
*
* The PDU is ciphered and integrity protected if NAS security is configured,
* the header type requires security protection and the current security context is valid.
* The function also performs a length check.
*
* @param pdu The NAS PDU already packed inside a byte_buffer
* @param sec_hdr_type Security header type of the message
* @return True if successful, false otherwise
*/
int nas::apply_security_config(srslte::unique_byte_buffer_t& pdu, uint8_t sec_hdr_type)
{
if (have_ctxt) {
if (pdu->N_bytes > 5) {
if (sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED ||
sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED_WITH_NEW_EPS_SECURITY_CONTEXT) {
cipher_encrypt(pdu.get());
}
if (sec_hdr_type >= LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY) {
integrity_generate(
&k_nas_int[16], ctxt.tx_count, SECURITY_DIRECTION_UPLINK, &pdu->msg[5], pdu->N_bytes - 5, &pdu->msg[1]);
}
} else {
nas_log->error("Invalid PDU size %d\n", pdu->N_bytes);
return SRSLTE_ERROR;
}
} else {
nas_log->debug("Not applying security for PDU. No context configured.\n");
}
return SRSLTE_SUCCESS;
}
/**
* Reset and delete any GUTI, TAI list, last visited registered TAI, list of equivalent PLMNs and KSI
*/
void nas::reset_security_context()
{
have_guti = false;
have_ctxt = false;
current_sec_hdr = LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS;
ctxt = {};
ctxt.ksi = LIBLTE_MME_NAS_KEY_SET_IDENTIFIER_NO_KEY_AVAILABLE;
}
/*******************************************************************************
* Parsers
******************************************************************************/
void nas::parse_attach_accept(uint32_t lcid, unique_byte_buffer_t pdu)
{
if (!pdu) {
nas_log->error("Invalid PDU\n");
return;
}
if (pdu->N_bytes <= 5) {
nas_log->error("Invalid attach accept PDU size (%d)\n", pdu->N_bytes);
return;
}
nas_log->info("Received Attach Accept\n");
// stop T3410
if (t3410.is_running()) {
nas_log->debug("Stopping T3410\n");
t3410.stop();
}
LIBLTE_MME_ATTACH_ACCEPT_MSG_STRUCT attach_accept = {};
liblte_mme_unpack_attach_accept_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &attach_accept);
if (attach_accept.eps_attach_result == LIBLTE_MME_EPS_ATTACH_RESULT_EPS_ONLY) {
// TODO: Handle t3412.unit
// TODO: Handle tai_list
if (attach_accept.guti_present) {
memcpy(&ctxt.guti, &attach_accept.guti.guti, sizeof(LIBLTE_MME_EPS_MOBILE_ID_GUTI_STRUCT));
have_guti = true;
// Update RRC UE-Idenity
s_tmsi_t s_tmsi;
s_tmsi.mmec = ctxt.guti.mme_code;
s_tmsi.m_tmsi = ctxt.guti.m_tmsi;
rrc->set_ue_identity(s_tmsi);
}
if (attach_accept.lai_present) {
; // Do nothing;
}
if (attach_accept.ms_id_present) {
; // Do nothing;
}
if (attach_accept.emm_cause_present) {
; // Do nothing;
}
if (attach_accept.t3402_present) {
; // Do nothing;
}
if (attach_accept.t3412_ext_present) {
; // Do nothing;
}
if (attach_accept.t3423_present) {
; // Do nothing;
}
if (attach_accept.equivalent_plmns_present) {
; // Do nothing;
}
if (attach_accept.emerg_num_list_present) {
; // Do nothing;
}
if (attach_accept.eps_network_feature_support_present) {
; // Do nothing;
}
if (attach_accept.additional_update_result_present) {
; // Do nothing;
}
LIBLTE_MME_ACTIVATE_DEFAULT_EPS_BEARER_CONTEXT_REQUEST_MSG_STRUCT act_def_eps_bearer_context_req = {};
liblte_mme_unpack_activate_default_eps_bearer_context_request_msg(&attach_accept.esm_msg,
&act_def_eps_bearer_context_req);
if ((cfg.apn_protocol == "ipv4" && LIBLTE_MME_PDN_TYPE_IPV6 == act_def_eps_bearer_context_req.pdn_addr.pdn_type) ||
(cfg.apn_protocol == "ipv6" && LIBLTE_MME_PDN_TYPE_IPV4 == act_def_eps_bearer_context_req.pdn_addr.pdn_type)) {
nas_log->error("Failed to attach -- Mismatch between PDN protocol and PDN type in attach accept.\n");
return;
}
if (("ipv4v6" == cfg.apn_protocol &&
LIBLTE_MME_PDN_TYPE_IPV4 == act_def_eps_bearer_context_req.pdn_addr.pdn_type) ||
("ipv4v6" == cfg.apn_protocol &&
LIBLTE_MME_PDN_TYPE_IPV6 == act_def_eps_bearer_context_req.pdn_addr.pdn_type)) {
nas_log->warning("Requested IPv4v6, but only received a single PDN address.\n");
nas_log->warning("EMM Cause: %d\n", attach_accept.emm_cause);
}
if (LIBLTE_MME_PDN_TYPE_IPV4 == act_def_eps_bearer_context_req.pdn_addr.pdn_type) {
ip_addr = 0;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[0] << 24u;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[1] << 16u;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[2] << 8u;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[3];
nas_log->info("Network attach successful. APN: %s, IP: %u.%u.%u.%u\n",
act_def_eps_bearer_context_req.apn.apn,
act_def_eps_bearer_context_req.pdn_addr.addr[0],
act_def_eps_bearer_context_req.pdn_addr.addr[1],
act_def_eps_bearer_context_req.pdn_addr.addr[2],
act_def_eps_bearer_context_req.pdn_addr.addr[3]);
srslte::console("Network attach successful. IP: %u.%u.%u.%u\n",
act_def_eps_bearer_context_req.pdn_addr.addr[0],
act_def_eps_bearer_context_req.pdn_addr.addr[1],
act_def_eps_bearer_context_req.pdn_addr.addr[2],
act_def_eps_bearer_context_req.pdn_addr.addr[3]);
// Setup GW
char* err_str = nullptr;
if (gw->setup_if_addr(rrc->get_lcid_for_eps_bearer(act_def_eps_bearer_context_req.eps_bearer_id),
LIBLTE_MME_PDN_TYPE_IPV4,
ip_addr,
nullptr,
err_str)) {
nas_log->error("%s - %s\n", gw_setup_failure_str.c_str(), err_str);
srslte::console("%s\n", gw_setup_failure_str.c_str());
}
} else if (LIBLTE_MME_PDN_TYPE_IPV6 == act_def_eps_bearer_context_req.pdn_addr.pdn_type) {
memcpy(ipv6_if_id, act_def_eps_bearer_context_req.pdn_addr.addr, 8);
nas_log->info("Network attach successful. APN: %s, IPv6 interface id: %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
act_def_eps_bearer_context_req.apn.apn,
act_def_eps_bearer_context_req.pdn_addr.addr[0],
act_def_eps_bearer_context_req.pdn_addr.addr[1],
act_def_eps_bearer_context_req.pdn_addr.addr[2],
act_def_eps_bearer_context_req.pdn_addr.addr[3],
act_def_eps_bearer_context_req.pdn_addr.addr[4],
act_def_eps_bearer_context_req.pdn_addr.addr[5],
act_def_eps_bearer_context_req.pdn_addr.addr[6],
act_def_eps_bearer_context_req.pdn_addr.addr[7]);
srslte::console("Network attach successful. IPv6 interface Id: %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
act_def_eps_bearer_context_req.pdn_addr.addr[0],
act_def_eps_bearer_context_req.pdn_addr.addr[1],
act_def_eps_bearer_context_req.pdn_addr.addr[2],
act_def_eps_bearer_context_req.pdn_addr.addr[3],
act_def_eps_bearer_context_req.pdn_addr.addr[4],
act_def_eps_bearer_context_req.pdn_addr.addr[5],
act_def_eps_bearer_context_req.pdn_addr.addr[6],
act_def_eps_bearer_context_req.pdn_addr.addr[7]);
// Setup GW
char* err_str = nullptr;
if (gw->setup_if_addr(rrc->get_lcid_for_eps_bearer(act_def_eps_bearer_context_req.eps_bearer_id),
LIBLTE_MME_PDN_TYPE_IPV6,
0,
ipv6_if_id,
err_str)) {
nas_log->error("%s - %s\n", gw_setup_failure_str.c_str(), err_str);
srslte::console("%s\n", gw_setup_failure_str.c_str());
}
} else if (LIBLTE_MME_PDN_TYPE_IPV4V6 == act_def_eps_bearer_context_req.pdn_addr.pdn_type) {
memcpy(ipv6_if_id, act_def_eps_bearer_context_req.pdn_addr.addr, 8);
// IPv6
nas_log->info("Network attach successful. APN: %s, IPv6 interface id: %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
act_def_eps_bearer_context_req.apn.apn,
act_def_eps_bearer_context_req.pdn_addr.addr[0],
act_def_eps_bearer_context_req.pdn_addr.addr[1],
act_def_eps_bearer_context_req.pdn_addr.addr[2],
act_def_eps_bearer_context_req.pdn_addr.addr[3],
act_def_eps_bearer_context_req.pdn_addr.addr[4],
act_def_eps_bearer_context_req.pdn_addr.addr[5],
act_def_eps_bearer_context_req.pdn_addr.addr[6],
act_def_eps_bearer_context_req.pdn_addr.addr[7]);
srslte::console("Network attach successful. IPv6 interface Id: %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
act_def_eps_bearer_context_req.pdn_addr.addr[0],
act_def_eps_bearer_context_req.pdn_addr.addr[1],
act_def_eps_bearer_context_req.pdn_addr.addr[2],
act_def_eps_bearer_context_req.pdn_addr.addr[3],
act_def_eps_bearer_context_req.pdn_addr.addr[4],
act_def_eps_bearer_context_req.pdn_addr.addr[5],
act_def_eps_bearer_context_req.pdn_addr.addr[6],
act_def_eps_bearer_context_req.pdn_addr.addr[7]);
// IPv4
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[8] << 24u;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[9] << 16u;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[10] << 8u;
ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[11];
nas_log->info("Network attach successful. APN: %s, IP: %u.%u.%u.%u\n",
act_def_eps_bearer_context_req.apn.apn,
act_def_eps_bearer_context_req.pdn_addr.addr[8],
act_def_eps_bearer_context_req.pdn_addr.addr[9],
act_def_eps_bearer_context_req.pdn_addr.addr[10],
act_def_eps_bearer_context_req.pdn_addr.addr[11]);
srslte::console("Network attach successful. IP: %u.%u.%u.%u\n",
act_def_eps_bearer_context_req.pdn_addr.addr[8],
act_def_eps_bearer_context_req.pdn_addr.addr[9],
act_def_eps_bearer_context_req.pdn_addr.addr[10],
act_def_eps_bearer_context_req.pdn_addr.addr[11]);
char* err_str = nullptr;
if (gw->setup_if_addr(rrc->get_lcid_for_eps_bearer(act_def_eps_bearer_context_req.eps_bearer_id),
LIBLTE_MME_PDN_TYPE_IPV4V6,
ip_addr,
ipv6_if_id,
err_str)) {
nas_log->error("%s - %s\n", gw_setup_failure_str.c_str(), err_str);
srslte::console("%s\n", gw_setup_failure_str.c_str());
}
} else {
nas_log->error("PDN type not IPv4, IPv6 nor IPv4v6\n");
return;
}
if (act_def_eps_bearer_context_req.transaction_id_present) {
transaction_id = act_def_eps_bearer_context_req.proc_transaction_id;
}
// Search for DNS entry in protocol config options
if (act_def_eps_bearer_context_req.protocol_cnfg_opts_present) {
for (uint32_t i = 0; i < act_def_eps_bearer_context_req.protocol_cnfg_opts.N_opts; i++) {
if (act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].id ==
LIBLTE_MME_ADDITIONAL_PARAMETERS_DL_DNS_SERVER_IPV4_ADDRESS) {
uint32_t dns_addr = 0;
dns_addr |= act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[0] << 24u;
dns_addr |= act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[1] << 16u;
dns_addr |= act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[2] << 8u;
dns_addr |= act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[3];
nas_log->info("DNS: %u.%u.%u.%u\n",
act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[0],
act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[1],
act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[2],
act_def_eps_bearer_context_req.protocol_cnfg_opts.opt[i].contents[3]);
}
}
}
// TODO: Handle the following parameters
// act_def_eps_bearer_context_req.eps_qos.qci
// act_def_eps_bearer_context_req.eps_qos.br_present
// act_def_eps_bearer_context_req.eps_qos.br_ext_present
// act_def_eps_bearer_context_req.apn.apn
// act_def_eps_bearer_context_req.negotiated_qos_present
// act_def_eps_bearer_context_req.llc_sapi_present
// act_def_eps_bearer_context_req.radio_prio_present
// act_def_eps_bearer_context_req.packet_flow_id_present
// act_def_eps_bearer_context_req.apn_ambr_present
// act_def_eps_bearer_context_req.protocol_cnfg_opts_present
// act_def_eps_bearer_context_req.connectivity_type_present
// TODO: Setup the default EPS bearer context
eps_bearer_t bearer = {};
bearer.type = DEFAULT_EPS_BEARER;
bearer.eps_bearer_id = act_def_eps_bearer_context_req.eps_bearer_id;
if (eps_bearer.insert(eps_bearer_map_pair_t(bearer.eps_bearer_id, bearer)).second) {
// bearer added successfully
enter_state(EMM_STATE_REGISTERED);
attach_attempt_counter = 0; // reset according to 5.5.1.1
// send attach complete
send_attach_complete(transaction_id, bearer.eps_bearer_id);
} else {
// bearer already exists (perhaps the attach complete got lost and this is a retx?)
// TODO: what are we supposed to do in this case?
nas_log->error("Error adding EPS bearer.\n");
}
} else {
nas_log->info("Not handling attach type %u\n", attach_accept.eps_attach_result);
enter_emm_deregistered();
}
ctxt.rx_count++;
}
void nas::parse_attach_reject(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_ATTACH_REJECT_MSG_STRUCT attach_rej;
ZERO_OBJECT(attach_rej);
liblte_mme_unpack_attach_reject_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &attach_rej);
nas_log->warning("Received Attach Reject. Cause= %02X\n", attach_rej.emm_cause);
srslte::console("Received Attach Reject. Cause= %02X\n", attach_rej.emm_cause);
// stop T3410
if (t3410.is_running()) {
nas_log->debug("Stopping T3410\n");
t3410.stop();
}
// Reset attach attempt counter according to 5.5.1.1
if (attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_PLMN_NOT_ALLOWED ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_TRACKING_AREA_NOT_ALLOWED ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_ROAMING_NOT_ALLOWED_IN_THIS_TRACKING_AREA ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_EPS_SERVICES_NOT_ALLOWED_IN_THIS_PLMN ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_NO_SUITABLE_CELLS_IN_TRACKING_AREA ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_NOT_AUTHORIZED_FOR_THIS_CSG) {
attach_attempt_counter = 0;
}
// 5.5.1.2.5
if (attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_ILLEGAL_UE ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_ILLEGAL_ME ||
attach_rej.emm_cause == LIBLTE_MME_EMM_CAUSE_REQUESTED_SERVICE_OPTION_NOT_AUTHORIZED) {
// delete security context
reset_security_context();
}
// TODO: handle other relevant reject causes
enter_emm_deregistered();
}
void nas::parse_authentication_request(uint32_t lcid, unique_byte_buffer_t pdu, const uint8_t sec_hdr_type)
{
LIBLTE_MME_AUTHENTICATION_REQUEST_MSG_STRUCT auth_req = {};
nas_log->info("Received Authentication Request\n");
liblte_mme_unpack_authentication_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &auth_req);
ctxt.rx_count++;
// Generate authentication response using RAND, AUTN & KSI-ASME
uint16 mcc, mnc;
mcc = rrc->get_mcc();
mnc = rrc->get_mnc();
nas_log->info("MCC=%d, MNC=%d\n", mcc, mnc);
uint8_t res[16];
int res_len = 0;
nas_log->debug_hex(auth_req.rand, 16, "Authentication request RAND\n");
nas_log->debug_hex(auth_req.autn, 16, "Authentication request AUTN\n");
auth_result_t auth_result =
usim->generate_authentication_response(auth_req.rand, auth_req.autn, mcc, mnc, res, &res_len, ctxt.k_asme);
if (LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE == auth_req.nas_ksi.tsc_flag) {
ctxt.ksi = auth_req.nas_ksi.nas_ksi;
} else {
nas_log->error("NAS mapped security context not currently supported\n");
srslte::console("Warning: NAS mapped security context not currently supported\n");
}
if (auth_result == AUTH_OK) {
nas_log->info("Network authentication successful\n");
// MME wants to re-establish security context, use provided protection level until security (re-)activation
current_sec_hdr = sec_hdr_type;
send_authentication_response(res, res_len);
nas_log->info_hex(ctxt.k_asme, 32, "Generated k_asme:\n");
set_k_enb_count(0);
auth_request = true;
} else if (auth_result == AUTH_SYNCH_FAILURE) {
nas_log->error("Network authentication synchronization failure.\n");
send_authentication_failure(LIBLTE_MME_EMM_CAUSE_SYNCH_FAILURE, res);
} else {
nas_log->warning("Network authentication failure\n");
srslte::console("Warning: Network authentication failure\n");
send_authentication_failure(LIBLTE_MME_EMM_CAUSE_MAC_FAILURE, nullptr);
}
}
void nas::parse_authentication_reject(uint32_t lcid, unique_byte_buffer_t pdu)
{
nas_log->warning("Received Authentication Reject\n");
enter_emm_deregistered();
// TODO: Command RRC to release?
}
void nas::parse_identity_request(unique_byte_buffer_t pdu, const uint8_t sec_hdr_type)
{
LIBLTE_MME_ID_REQUEST_MSG_STRUCT id_req = {};
liblte_mme_unpack_identity_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &id_req);
nas_log->info("Received Identity Request. ID type: %d\n", id_req.id_type);
ctxt.rx_count++;
// do not respond if request is not protected (TS 24.301 Sec. 4.4.4.2)
if (sec_hdr_type >= LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY ||
(sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS && id_req.id_type == LIBLTE_MME_MOBILE_ID_TYPE_IMSI)) {
current_sec_hdr = sec_hdr_type; // use MME protection level until security (re-)activation
send_identity_response(id_req.id_type);
} else {
nas_log->info("Not sending identity response due to missing integrity protection.\n");
}
}
void nas::parse_security_mode_command(uint32_t lcid, unique_byte_buffer_t pdu)
{
if (!pdu) {
nas_log->error("Invalid PDU\n");
return;
}
if (pdu->N_bytes <= 5) {
nas_log->error("Invalid security mode command PDU size (%d)\n", pdu->N_bytes);
return;
}
LIBLTE_MME_SECURITY_MODE_COMMAND_MSG_STRUCT sec_mode_cmd = {};
liblte_mme_unpack_security_mode_command_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &sec_mode_cmd);
nas_log->info("Received Security Mode Command ksi: %d, eea: %s, eia: %s\n",
sec_mode_cmd.nas_ksi.nas_ksi,
ciphering_algorithm_id_text[sec_mode_cmd.selected_nas_sec_algs.type_of_eea],
integrity_algorithm_id_text[sec_mode_cmd.selected_nas_sec_algs.type_of_eia]);
if (sec_mode_cmd.nas_ksi.tsc_flag != LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE) {
nas_log->error("Mapped security context not supported\n");
return;
}
if (have_ctxt) {
if (sec_mode_cmd.nas_ksi.nas_ksi != ctxt.ksi) {
nas_log->warning("Sending Security Mode Reject due to key set ID mismatch\n");
send_security_mode_reject(LIBLTE_MME_EMM_CAUSE_SECURITY_MODE_REJECTED_UNSPECIFIED);
return;
}
}
// MME is setting up security context
// TODO: check nonce (not sent by Amari)
// Check capabilities replay
if (!check_cap_replay(&sec_mode_cmd.ue_security_cap)) {
nas_log->warning("Sending Security Mode Reject due to security capabilities replay mismatch\n");
send_security_mode_reject(LIBLTE_MME_EMM_CAUSE_UE_SECURITY_CAPABILITIES_MISMATCH);
return;
}
// Reset counters (as per 24.301 5.4.3.2), only needed for initial security mode command
if (auth_request) {
ctxt.rx_count = 0;
ctxt.tx_count = 0;
auth_request = false;
}
ctxt.cipher_algo = (CIPHERING_ALGORITHM_ID_ENUM)sec_mode_cmd.selected_nas_sec_algs.type_of_eea;
ctxt.integ_algo = (INTEGRITY_ALGORITHM_ID_ENUM)sec_mode_cmd.selected_nas_sec_algs.type_of_eia;
// Check capabilities
if (!eea_caps[ctxt.cipher_algo] || !eia_caps[ctxt.integ_algo]) {
nas_log->warning("Sending Security Mode Reject due to security capabilities mismatch\n");
send_security_mode_reject(LIBLTE_MME_EMM_CAUSE_UE_SECURITY_CAPABILITIES_MISMATCH);
return;
}
// Generate NAS keys
usim->generate_nas_keys(ctxt.k_asme, k_nas_enc, k_nas_int, ctxt.cipher_algo, ctxt.integ_algo);
nas_log->info_hex(k_nas_enc, 32, "NAS encryption key - k_nas_enc");
nas_log->info_hex(k_nas_int, 32, "NAS integrity key - k_nas_int");
nas_log->debug(
"Generating integrity check. integ_algo:%d, count_dl:%d, lcid:%d\n", ctxt.integ_algo, ctxt.rx_count, lcid);
if (not integrity_check(pdu.get())) {
nas_log->warning("Sending Security Mode Reject due to integrity check failure\n");
send_security_mode_reject(LIBLTE_MME_EMM_CAUSE_MAC_FAILURE);
return;
}
ctxt.rx_count++;
LIBLTE_MME_SECURITY_MODE_COMPLETE_MSG_STRUCT sec_mode_comp = {};
if (sec_mode_cmd.imeisv_req_present && LIBLTE_MME_IMEISV_REQUESTED == sec_mode_cmd.imeisv_req) {
sec_mode_comp.imeisv_present = true;
sec_mode_comp.imeisv.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMEISV;
usim->get_imei_vec(sec_mode_comp.imeisv.imeisv, 15);
sec_mode_comp.imeisv.imeisv[14] = ue_svn_oct1;
sec_mode_comp.imeisv.imeisv[15] = ue_svn_oct2;
} else {
sec_mode_comp.imeisv_present = false;
}
// Take security context into use and use new security header
have_ctxt = true;
current_sec_hdr = LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED_WITH_NEW_EPS_SECURITY_CONTEXT;
// Pack and send response
pdu->clear();
liblte_mme_pack_security_mode_complete_msg(
&sec_mode_comp, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info("Sending Security Mode Complete nas_current_ctxt.tx_count=%d, RB=%s\n",
ctxt.tx_count,
rrc->get_rb_name(lcid).c_str());
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
// switch security header for all following messages
current_sec_hdr = LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED;
}
void nas::parse_service_reject(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_SERVICE_REJECT_MSG_STRUCT service_reject;
if (liblte_mme_unpack_service_reject_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &service_reject)) {
nas_log->error("Error unpacking service reject.\n");
return;
}
srslte::console("Received service reject with EMM cause=0x%x.\n", service_reject.emm_cause);
if (service_reject.t3446_present) {
nas_log->info(
"Received service reject with EMM cause=0x%x and t3446=%d\n", service_reject.emm_cause, service_reject.t3446);
}
// TODO: handle NAS backoff-timers correctly
enter_emm_deregistered();
reset_security_context();
// Send attach request after receiving service reject
pdu->clear();
gen_attach_request(pdu);
rrc->write_sdu(std::move(pdu));
}
void nas::parse_esm_information_request(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_ESM_INFORMATION_REQUEST_MSG_STRUCT esm_info_req;
liblte_mme_unpack_esm_information_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &esm_info_req);
nas_log->info("ESM information request received for beaser=%d, transaction_id=%d\n",
esm_info_req.eps_bearer_id,
esm_info_req.proc_transaction_id);
ctxt.rx_count++;
// send response
send_esm_information_response(esm_info_req.proc_transaction_id);
}
void nas::parse_emm_information(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_EMM_INFORMATION_MSG_STRUCT emm_info = {};
liblte_mme_unpack_emm_information_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &emm_info);
std::string str = emm_info_str(&emm_info);
nas_log->info("Received EMM Information: %s\n", str.c_str());
srslte::console("%s\n", str.c_str());
ctxt.rx_count++;
}
void nas::parse_detach_request(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_DETACH_REQUEST_MSG_STRUCT detach_request;
liblte_mme_unpack_detach_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &detach_request);
ctxt.rx_count++;
nas_log->info("Received detach request (type=%d)\n", detach_request.detach_type.type_of_detach);
switch (state) {
case EMM_STATE_DEREGISTERED_INITIATED:
nas_log->info("Received detach from network while performing UE initiated detach. Aborting UE detach.\n");
// intentional fall-through to complete detach procedure
case EMM_STATE_REGISTERED:
// send accept and leave state
send_detach_accept();
enter_emm_deregistered();
// schedule reattach if required
if (detach_request.detach_type.type_of_detach == LIBLTE_MME_TOD_DL_REATTACH_REQUIRED) {
// Section 5.5.2.3.2
// delay re-attach to allow RRC to release
nas_log->debug("Starting reattach timer\n");
reattach_timer.run();
}
break;
default:
nas_log->warning("Received detach request in invalid state (%s)\n", emm_state_text[state]);
break;
}
}
void nas::parse_activate_dedicated_eps_bearer_context_request(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_REQUEST_MSG_STRUCT request;
liblte_mme_unpack_activate_dedicated_eps_bearer_context_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &request);
nas_log->info(
"Received Activate Dedicated EPS bearer context request (eps_bearer_id=%d, linked_bearer_id=%d, proc_id=%d)\n",
request.eps_bearer_id,
request.linked_eps_bearer_id,
request.proc_transaction_id);
ctxt.rx_count++;
LIBLTE_MME_TRAFFIC_FLOW_TEMPLATE_STRUCT* tft = &request.tft;
nas_log->info("Traffic Flow Template: TFT OP code 0x%x, Filter list size %d, Parameter list size %d\n",
tft->tft_op_code,
tft->packet_filter_list_size,
tft->parameter_list_size);
// check the a linked default bearer exists
if (eps_bearer.find(request.linked_eps_bearer_id) == eps_bearer.end()) {
nas_log->error("No linked default EPS bearer found (%d).\n", request.linked_eps_bearer_id);
// TODO: send reject according to 24.301 Sec 6.4.2.5 paragraph c
return;
}
// check if the dedicated EPS bearer already exists
if (eps_bearer.find(request.eps_bearer_id) != eps_bearer.end()) {
// according to 24.301 Sec 6.4.2.5 paragraph b) the existing bearer shall be deactived before proceeding
nas_log->error("EPS bearer already exists (%d). Removing it.\n", request.eps_bearer_id);
// remove bearer
eps_bearer_map_t::iterator it = eps_bearer.find(request.eps_bearer_id);
eps_bearer.erase(it);
}
// create new bearer
eps_bearer_t bearer = {};
bearer.type = DEDICATED_EPS_BEARER;
bearer.eps_bearer_id = request.eps_bearer_id;
bearer.linked_eps_bearer_id = request.linked_eps_bearer_id;
if (not eps_bearer.insert(eps_bearer_map_pair_t(bearer.eps_bearer_id, bearer)).second) {
nas_log->error("Error adding EPS bearer.\n");
return;
}
// apply packet filters to GW
gw->apply_traffic_flow_template(request.eps_bearer_id, rrc->get_lcid_for_eps_bearer(request.eps_bearer_id), tft);
send_activate_dedicated_eps_bearer_context_accept(request.proc_transaction_id, request.eps_bearer_id);
}
void nas::parse_deactivate_eps_bearer_context_request(unique_byte_buffer_t pdu)
{
LIBLTE_MME_DEACTIVATE_EPS_BEARER_CONTEXT_REQUEST_MSG_STRUCT request;
liblte_mme_unpack_deactivate_eps_bearer_context_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &request);
nas_log->info("Received Deactivate EPS bearer context request (eps_bearer_id=%d, proc_id=%d, cause=0x%X)\n",
request.eps_bearer_id,
request.proc_transaction_id,
request.esm_cause);
ctxt.rx_count++;
// check if bearer exists
if (eps_bearer.find(request.eps_bearer_id) == eps_bearer.end()) {
nas_log->error("EPS bearer doesn't exist (eps_bearer_id=%d)\n", request.eps_bearer_id);
// fixme: send proper response
return;
}
// remove bearer
eps_bearer_map_t::iterator it = eps_bearer.find(request.eps_bearer_id);
eps_bearer.erase(it);
nas_log->info("Removed EPS bearer context (eps_bearer_id=%d)\n", request.eps_bearer_id);
send_deactivate_eps_bearer_context_accept(request.proc_transaction_id, request.eps_bearer_id);
}
void nas::parse_modify_eps_bearer_context_request(srslte::unique_byte_buffer_t pdu)
{
LIBLTE_MME_MODIFY_EPS_BEARER_CONTEXT_REQUEST_MSG_STRUCT request;
liblte_mme_unpack_modify_eps_bearer_context_request_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &request);
nas_log->info("Received Modify EPS bearer context request (eps_bearer_id=%d, proc_id=%d)\n",
request.eps_bearer_id,
request.proc_transaction_id);
ctxt.rx_count++;
// check if bearer exists
if (eps_bearer.find(request.eps_bearer_id) == eps_bearer.end()) {
nas_log->error("EPS bearer doesn't exist (eps_bearer_id=%d)\n", request.eps_bearer_id);
// fixme: send proper response
return;
}
// fixme: carry out modification
nas_log->info("Modified EPS bearer context (eps_bearer_id=%d)\n", request.eps_bearer_id);
send_modify_eps_bearer_context_accept(request.proc_transaction_id, request.eps_bearer_id);
}
void nas::parse_activate_test_mode(uint32_t lcid, unique_byte_buffer_t pdu)
{
nas_log->info("Received Activate test mode\n");
ctxt.rx_count++;
send_activate_test_mode_complete();
}
void nas::parse_close_ue_test_loop(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_UE_TEST_LOOP_MODE_ENUM mode = static_cast<LIBLTE_MME_UE_TEST_LOOP_MODE_ENUM>(pdu->msg[8]);
nas_log->info("Received Close UE test loop for %s\n", liblte_ue_test_loop_mode_text[mode]);
switch (mode) {
case LIBLTE_MME_UE_TEST_LOOP_MODE_A:
gw->set_test_loop_mode(gw_interface_nas::TEST_LOOP_MODE_A_ACTIVE);
break;
case LIBLTE_MME_UE_TEST_LOOP_MODE_B:
gw->set_test_loop_mode(gw_interface_nas::TEST_LOOP_MODE_B_ACTIVE, pdu->msg[9] * 1000);
break;
case LIBLTE_MME_UE_TEST_LOOP_MODE_C:
gw->set_test_loop_mode(gw_interface_nas::TEST_LOOP_MODE_C_ACTIVE);
break;
default:
break;
}
ctxt.rx_count++;
send_close_ue_test_loop_complete();
}
void nas::parse_emm_status(uint32_t lcid, unique_byte_buffer_t pdu)
{
LIBLTE_MME_EMM_STATUS_MSG_STRUCT emm_status;
liblte_mme_unpack_emm_status_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &emm_status);
ctxt.rx_count++;
switch (emm_status.emm_cause) {
case LIBLTE_MME_ESM_CAUSE_INVALID_EPS_BEARER_IDENTITY:
nas_log->info("Received EMM status: Invalid EPS bearer identity\n");
// TODO: abort any ongoing procedure (see Sec. 6.7 in TS 24.301)
break;
case LIBLTE_MME_ESM_CAUSE_INVALID_PTI_VALUE:
nas_log->info("Received EMM status: Invalid PTI value\n");
// TODO: abort any ongoing procedure (see Sec. 6.7 in TS 24.301)
break;
case LIBLTE_MME_ESM_CAUSE_MESSAGE_TYPE_NON_EXISTENT_OR_NOT_IMPLEMENTED:
nas_log->info("Received EMM status: Invalid PTI value\n");
// TODO: see Sec. 6.7 in TS 24.301
break;
default:
nas_log->info("Received unknown EMM status (cause=%d)\n", emm_status.emm_cause);
break;
}
}
/*******************************************************************************
* Senders
******************************************************************************/
void nas::gen_attach_request(srslte::unique_byte_buffer_t& msg)
{
if (msg == nullptr) {
nas_log->error("Fatal Error: Couldn't allocate PDU in gen_attach_request().\n");
return;
}
LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT attach_req;
bzero(&attach_req, sizeof(LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT));
nas_log->info("Generating attach request\n");
attach_req.eps_attach_type = LIBLTE_MME_EPS_ATTACH_TYPE_EPS_ATTACH;
for (u_int32_t i = 0; i < 8; i++) {
attach_req.ue_network_cap.eea[i] = eea_caps[i];
attach_req.ue_network_cap.eia[i] = eia_caps[i];
}
attach_req.ue_network_cap.uea_present = false; // UMTS encryption algos
attach_req.ue_network_cap.uia_present = false; // UMTS integrity algos
attach_req.ue_network_cap.ucs2_present = false;
attach_req.ms_network_cap_present = false; // A/Gb mode (2G) or Iu mode (3G)
attach_req.ue_network_cap.lpp_present = false;
attach_req.ue_network_cap.lcs_present = false;
attach_req.ue_network_cap.onexsrvcc_present = false;
attach_req.ue_network_cap.nf_present = false;
attach_req.old_p_tmsi_signature_present = false;
attach_req.additional_guti_present = false;
attach_req.last_visited_registered_tai_present = false;
attach_req.drx_param_present = false;
attach_req.old_lai_present = false;
attach_req.tmsi_status_present = false;
attach_req.ms_cm2_present = false;
attach_req.ms_cm3_present = false;
attach_req.supported_codecs_present = false;
attach_req.additional_update_type_present = false;
attach_req.voice_domain_pref_and_ue_usage_setting_present = false;
attach_req.device_properties_present = false;
attach_req.old_guti_type_present = false;
// ESM message (PDN connectivity request) for first default bearer
gen_pdn_connectivity_request(&attach_req.esm_msg);
// GUTI or IMSI attach
if (have_guti && have_ctxt) {
attach_req.tmsi_status_present = true;
attach_req.tmsi_status = LIBLTE_MME_TMSI_STATUS_VALID_TMSI;
attach_req.eps_mobile_id.type_of_id = LIBLTE_MME_EPS_MOBILE_ID_TYPE_GUTI;
memcpy(&attach_req.eps_mobile_id.guti, &ctxt.guti, sizeof(LIBLTE_MME_EPS_MOBILE_ID_GUTI_STRUCT));
attach_req.old_guti_type = LIBLTE_MME_GUTI_TYPE_NATIVE;
attach_req.old_guti_type_present = true;
attach_req.nas_ksi.tsc_flag = LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE;
attach_req.nas_ksi.nas_ksi = ctxt.ksi;
nas_log->info("Requesting GUTI attach. "
"m_tmsi: %x, mcc: %x, mnc: %x, mme_group_id: %x, mme_code: %x\n",
ctxt.guti.m_tmsi,
ctxt.guti.mcc,
ctxt.guti.mnc,
ctxt.guti.mme_group_id,
ctxt.guti.mme_code);
// According to Sec 4.4.5, the attach request is always unciphered, even if a context exists
liblte_mme_pack_attach_request_msg(
&attach_req, LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)msg.get());
if (apply_security_config(msg, LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY)) {
nas_log->error("Error applying NAS security.\n");
return;
}
} else {
attach_req.eps_mobile_id.type_of_id = LIBLTE_MME_EPS_MOBILE_ID_TYPE_IMSI;
attach_req.nas_ksi.tsc_flag = LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE;
attach_req.nas_ksi.nas_ksi = LIBLTE_MME_NAS_KEY_SET_IDENTIFIER_NO_KEY_AVAILABLE;
usim->get_imsi_vec(attach_req.eps_mobile_id.imsi, 15);
nas_log->info("Requesting IMSI attach (IMSI=%s)\n", usim->get_imsi_str().c_str());
liblte_mme_pack_attach_request_msg(&attach_req, (LIBLTE_BYTE_MSG_STRUCT*)msg.get());
}
if (pcap != nullptr) {
pcap->write_nas(msg->msg, msg->N_bytes);
}
if (have_ctxt) {
set_k_enb_count(ctxt.tx_count);
ctxt.tx_count++;
}
// stop T3411 and T3402
if (t3411.is_running()) {
nas_log->debug("Stopping T3411\n");
t3411.stop();
}
if (t3402.is_running()) {
nas_log->debug("Stopping T3402\n");
t3402.stop();
}
// start T3410
nas_log->debug("Starting T3410\n");
t3410.run();
}
void nas::gen_service_request(srslte::unique_byte_buffer_t& msg)
{
if (msg == nullptr) {
nas_log->error("Fatal Error: Couldn't allocate PDU in gen_service_request().\n");
return;
}
nas_log->info("Generating service request\n");
// Pack the service request message directly
msg->msg[0] = (LIBLTE_MME_SECURITY_HDR_TYPE_SERVICE_REQUEST << 4u) | (LIBLTE_MME_PD_EPS_MOBILITY_MANAGEMENT);
msg->N_bytes++;
msg->msg[1] = (ctxt.ksi & 0x07u) << 5u;
msg->msg[1] |= ctxt.tx_count & 0x1Fu;
msg->N_bytes++;
uint8_t mac[4];
integrity_generate(&k_nas_int[16], ctxt.tx_count, SECURITY_DIRECTION_UPLINK, &msg->msg[0], 2, &mac[0]);
// Set the short MAC
msg->msg[2] = mac[2];
msg->N_bytes++;
msg->msg[3] = mac[3];
msg->N_bytes++;
if (pcap != nullptr) {
pcap->write_nas(msg->msg, msg->N_bytes);
}
set_k_enb_count(ctxt.tx_count);
ctxt.tx_count++;
}
void nas::gen_pdn_connectivity_request(LIBLTE_BYTE_MSG_STRUCT* msg)
{
LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT pdn_con_req = {};
nas_log->info("Generating PDN Connectivity Request\n");
// Set the PDN con req parameters
pdn_con_req.eps_bearer_id = 0x00; // Unassigned bearer ID
pdn_con_req.proc_transaction_id = 0x01; // First transaction ID
pdn_con_req.request_type = LIBLTE_MME_REQUEST_TYPE_INITIAL_REQUEST;
pdn_con_req.apn_present = false;
// Set PDN protocol type
if (cfg.apn_protocol == "ipv4" || cfg.apn_protocol.empty()) {
nas_log->debug("Requesting IPv4 PDN protocol\n");
pdn_con_req.pdn_type = LIBLTE_MME_PDN_TYPE_IPV4;
} else if (cfg.apn_protocol == "ipv6") {
nas_log->debug("Requesting IPv6 PDN protocol\n");
pdn_con_req.pdn_type = LIBLTE_MME_PDN_TYPE_IPV6;
} else if (cfg.apn_protocol == "ipv4v6") {
nas_log->debug("Requesting IPv4v6 PDN protocol\n");
pdn_con_req.pdn_type = LIBLTE_MME_PDN_TYPE_IPV4V6;
} else {
nas_log->warning("Unsupported PDN prtocol. Defaulting to IPv4\n");
srslte::console("Unsupported PDN prtocol: %s. Defaulting to IPv4\n", cfg.apn_protocol.c_str());
pdn_con_req.pdn_type = LIBLTE_MME_PDN_TYPE_IPV4;
}
// Set the optional flags
if (cfg.apn_name.empty()) {
pdn_con_req.esm_info_transfer_flag_present = false;
} else {
// request ESM info transfer is APN is specified
pdn_con_req.esm_info_transfer_flag_present = true;
pdn_con_req.esm_info_transfer_flag = LIBLTE_MME_ESM_INFO_TRANSFER_FLAG_REQUIRED;
}
pdn_con_req.protocol_cnfg_opts_present = false;
pdn_con_req.device_properties_present = false;
// Pack the message
liblte_mme_pack_pdn_connectivity_request_msg(&pdn_con_req, msg);
}
void nas::send_security_mode_reject(uint8_t cause)
{
unique_byte_buffer_t msg = srslte::allocate_unique_buffer(*pool, true);
if (!msg) {
nas_log->error("Fatal Error: Couldn't allocate PDU in send_security_mode_reject().\n");
return;
}
LIBLTE_MME_SECURITY_MODE_REJECT_MSG_STRUCT sec_mode_rej = {0};
sec_mode_rej.emm_cause = cause;
liblte_mme_pack_security_mode_reject_msg(&sec_mode_rej, (LIBLTE_BYTE_MSG_STRUCT*)msg.get());
if (pcap != nullptr) {
pcap->write_nas(msg->msg, msg->N_bytes);
}
nas_log->info("Sending security mode reject\n");
rrc->write_sdu(std::move(msg));
}
/**
* Pack attach request message and send to RRC for transmission.
*/
void nas::send_attach_request()
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (!pdu) {
nas_log->error("Fatal Error: Couldn't allocate PDU in %s().\n", __FUNCTION__);
return;
}
gen_attach_request(pdu);
rrc->write_sdu(std::move(pdu));
}
void nas::send_detach_request(bool switch_off)
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (!pdu) {
nas_log->error("Fatal Error: Couldn't allocate PDU in %s().\n", __FUNCTION__);
return;
}
LIBLTE_MME_DETACH_REQUEST_MSG_STRUCT detach_request = {};
if (switch_off) {
detach_request.detach_type.switch_off = 1;
detach_request.detach_type.type_of_detach = LIBLTE_MME_SO_FLAG_SWITCH_OFF;
} else {
detach_request.detach_type.switch_off = 0;
detach_request.detach_type.type_of_detach = LIBLTE_MME_TOD_UL_EPS_DETACH;
}
// GUTI or IMSI detach
if (have_guti && have_ctxt) {
detach_request.eps_mobile_id.type_of_id = LIBLTE_MME_EPS_MOBILE_ID_TYPE_GUTI;
memcpy(&detach_request.eps_mobile_id.guti, &ctxt.guti, sizeof(LIBLTE_MME_EPS_MOBILE_ID_GUTI_STRUCT));
detach_request.nas_ksi.tsc_flag = LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE;
detach_request.nas_ksi.nas_ksi = ctxt.ksi;
nas_log->info("Sending detach request with GUTI\n"); // If sent as an Initial UE message, it cannot be ciphered
liblte_mme_pack_detach_request_msg(
&detach_request, LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY)) {
nas_log->error("Error applying NAS security.\n");
return;
}
} else {
detach_request.eps_mobile_id.type_of_id = LIBLTE_MME_EPS_MOBILE_ID_TYPE_IMSI;
detach_request.nas_ksi.tsc_flag = LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE;
detach_request.nas_ksi.nas_ksi = 0;
usim->get_imsi_vec(detach_request.eps_mobile_id.imsi, 15);
nas_log->info("Sending detach request with IMSI\n");
liblte_mme_pack_detach_request_msg(
&detach_request, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
}
if (switch_off) {
enter_emm_deregistered();
} else {
// we are expecting a response from the core
enter_state(EMM_STATE_DEREGISTERED_INITIATED);
// start T3421
nas_log->info("Starting T3421\n");
t3421.run();
}
if (rrc->is_connected()) {
rrc->write_sdu(std::move(pdu));
} else {
if (not rrc_connector.launch(establishment_cause_t::mo_sig, std::move(pdu))) {
nas_log->error("Failed to initiate RRC Connection Request\n");
}
callbacks.add_proc(rrc_connector);
}
ctxt.tx_count++;
}
void nas::send_attach_complete(const uint8_t& transaction_id_, const uint8_t& eps_bearer_id)
{
// Send EPS bearer context accept and attach complete
LIBLTE_MME_ATTACH_COMPLETE_MSG_STRUCT attach_complete = {};
LIBLTE_MME_ACTIVATE_DEFAULT_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT act_def_eps_bearer_context_accept = {};
act_def_eps_bearer_context_accept.eps_bearer_id = eps_bearer_id;
act_def_eps_bearer_context_accept.proc_transaction_id = transaction_id_;
act_def_eps_bearer_context_accept.protocol_cnfg_opts_present = false;
liblte_mme_pack_activate_default_eps_bearer_context_accept_msg(&act_def_eps_bearer_context_accept,
&attach_complete.esm_msg);
// Pack entire message
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
liblte_mme_pack_attach_complete_msg(
&attach_complete, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
// Write NAS pcap
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
// Instruct RRC to enable capabilities
rrc->enable_capabilities();
nas_log->info("Sending Attach Complete\n");
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_detach_accept()
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (!pdu) {
nas_log->error("Fatal Error: Couldn't allocate PDU in %s().\n", __FUNCTION__);
return;
}
LIBLTE_MME_DETACH_ACCEPT_MSG_STRUCT detach_accept;
bzero(&detach_accept, sizeof(detach_accept));
liblte_mme_pack_detach_accept_msg(&detach_accept, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info("Sending detach accept\n");
rrc->write_sdu(std::move(pdu));
}
void nas::send_authentication_response(const uint8_t* res, const size_t res_len)
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (!pdu) {
nas_log->error("Fatal Error: Couldn't allocate PDU in send_authentication_response().\n");
return;
}
LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT auth_res = {};
for (uint32_t i = 0; i < res_len; i++) {
auth_res.res[i] = res[i];
}
auth_res.res_len = res_len;
liblte_mme_pack_authentication_response_msg(
&auth_res, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info("Sending Authentication Response\n");
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_authentication_failure(const uint8_t cause, const uint8_t* auth_fail_param)
{
unique_byte_buffer_t msg = srslte::allocate_unique_buffer(*pool, true);
if (!msg) {
nas_log->error("Fatal Error: Couldn't allocate PDU in send_authentication_failure().\n");
return;
}
LIBLTE_MME_AUTHENTICATION_FAILURE_MSG_STRUCT auth_failure;
auth_failure.emm_cause = cause;
if (auth_fail_param != nullptr) {
memcpy(auth_failure.auth_fail_param, auth_fail_param, 14);
nas_log->debug_hex(auth_failure.auth_fail_param, 14, "auth_failure.auth_fail_param\n");
auth_failure.auth_fail_param_present = true;
} else {
auth_failure.auth_fail_param_present = false;
}
liblte_mme_pack_authentication_failure_msg(&auth_failure, (LIBLTE_BYTE_MSG_STRUCT*)msg.get());
if (pcap != nullptr) {
pcap->write_nas(msg->msg, msg->N_bytes);
}
nas_log->info("Sending authentication failure.\n");
rrc->write_sdu(std::move(msg));
}
void nas::send_identity_response(const uint8 id_type)
{
LIBLTE_MME_ID_RESPONSE_MSG_STRUCT id_resp = {};
switch (id_type) {
case LIBLTE_MME_MOBILE_ID_TYPE_IMSI:
id_resp.mobile_id.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMSI;
usim->get_imsi_vec(id_resp.mobile_id.imsi, 15);
break;
case LIBLTE_MME_MOBILE_ID_TYPE_IMEI:
id_resp.mobile_id.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMEI;
usim->get_imei_vec(id_resp.mobile_id.imei, 15);
break;
case LIBLTE_MME_MOBILE_ID_TYPE_IMEISV:
id_resp.mobile_id.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMEISV;
usim->get_imei_vec(id_resp.mobile_id.imeisv, 15);
id_resp.mobile_id.imeisv[14] = ue_svn_oct1;
id_resp.mobile_id.imeisv[15] = ue_svn_oct2;
break;
default:
nas_log->error("Unhandled ID type: %d\n", id_type);
return;
}
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (!pdu) {
nas_log->error("Fatal Error: Couldn't allocate PDU in send_identity_response().\n");
return;
}
liblte_mme_pack_identity_response_msg(&id_resp, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get());
// add security if needed
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_service_request()
{
unique_byte_buffer_t msg = srslte::allocate_unique_buffer(*pool, true);
if (!msg) {
nas_log->error("Fatal Error: Couldn't allocate PDU in send_service_request().\n");
return;
}
// Pack the service request message directly
msg->msg[0] = (LIBLTE_MME_SECURITY_HDR_TYPE_SERVICE_REQUEST << 4u) | (LIBLTE_MME_PD_EPS_MOBILITY_MANAGEMENT);
msg->N_bytes++;
msg->msg[1] = (ctxt.ksi & 0x07u) << 5u;
msg->msg[1] |= ctxt.tx_count & 0x1Fu;
msg->N_bytes++;
uint8_t mac[4];
integrity_generate(&k_nas_int[16], ctxt.tx_count, SECURITY_DIRECTION_UPLINK, &msg->msg[0], 2, &mac[0]);
// Set the short MAC
msg->msg[2] = mac[2];
msg->N_bytes++;
msg->msg[3] = mac[3];
msg->N_bytes++;
if (pcap != nullptr) {
pcap->write_nas(msg->msg, msg->N_bytes);
}
nas_log->info("Sending service request\n");
rrc->write_sdu(std::move(msg));
ctxt.tx_count++;
}
void nas::send_esm_information_response(const uint8 proc_transaction_id)
{
LIBLTE_MME_ESM_INFORMATION_RESPONSE_MSG_STRUCT esm_info_resp;
esm_info_resp.proc_transaction_id = proc_transaction_id;
esm_info_resp.eps_bearer_id = 0; // respone shall always have no bearer assigned
if (cfg.apn_name == "") {
esm_info_resp.apn_present = false;
} else {
nas_log->debug("Including APN %s in ESM info response\n", cfg.apn_name.c_str());
esm_info_resp.apn_present = true;
int len = std::min((int)cfg.apn_name.length(), LIBLTE_STRING_LEN - 1);
strncpy(esm_info_resp.apn.apn, cfg.apn_name.c_str(), len);
esm_info_resp.apn.apn[len] = '\0';
}
if (cfg.apn_user != "" && cfg.apn_user.length() < LIBLTE_STRING_LEN && cfg.apn_pass != "" &&
cfg.apn_pass.length() < LIBLTE_STRING_LEN) {
nas_log->debug("Including CHAP authentication for user %s in ESM info response\n", cfg.apn_user.c_str());
// Generate CHAP challenge
uint16_t len = 1 /* CHAP code */ + 1 /* ID */ + 2 /* complete length */ + 1 /* data value size */ +
16 /* data value */ + cfg.apn_user.length();
uint8_t challenge[len];
bzero(challenge, len * sizeof(uint8_t));
challenge[0] = 0x01; // challenge code
challenge[1] = chap_id; // ID
challenge[2] = (len >> 8u) & 0xffu;
challenge[3] = len & 0xffu;
challenge[4] = 16;
// Append random challenge value
for (int i = 0; i < 16; i++) {
challenge[5 + i] = rand() & 0xFFu;
}
// add user as name field
for (size_t i = 0; i < cfg.apn_user.length(); i++) {
const char* name = cfg.apn_user.c_str();
challenge[21 + i] = name[i];
}
// Generate response
uint8_t response[len];
bzero(response, len * sizeof(uint8_t));
response[0] = 0x02; // response code
response[1] = chap_id;
response[2] = (len >> 8u) & 0xffu;
response[3] = len & 0xffu;
response[4] = 16;
// Generate response value
uint16_t resp_val_len = 16 /* MD5 len */ + 1 /* ID */ + cfg.apn_pass.length();
uint8_t resp_val[resp_val_len];
resp_val[0] = chap_id;
// add secret
for (size_t i = 0; i < cfg.apn_pass.length(); i++) {
const char* pass = cfg.apn_pass.c_str();
resp_val[1 + i] = pass[i];
}
// copy original challenge behind secret
uint8_t* chal_val = &challenge[5];
memcpy(&resp_val[1 + cfg.apn_pass.length()], chal_val, 16);
// Compute MD5 of resp_val and add to response
security_md5(resp_val, resp_val_len, &response[5]);
// add user as name field again
for (size_t i = 0; i < cfg.apn_user.length(); i++) {
const char* name = cfg.apn_user.c_str();
response[21 + i] = name[i];
}
// Add challenge and response to ESM info response
esm_info_resp.protocol_cnfg_opts_present = true;
esm_info_resp.protocol_cnfg_opts.opt[0].id = LIBLTE_MME_CONFIGURATION_PROTOCOL_OPTIONS_CHAP;
memcpy(esm_info_resp.protocol_cnfg_opts.opt[0].contents, challenge, sizeof(challenge));
esm_info_resp.protocol_cnfg_opts.opt[0].len = sizeof(challenge);
esm_info_resp.protocol_cnfg_opts.opt[1].id = LIBLTE_MME_CONFIGURATION_PROTOCOL_OPTIONS_CHAP;
memcpy(esm_info_resp.protocol_cnfg_opts.opt[1].contents, response, sizeof(response));
esm_info_resp.protocol_cnfg_opts.opt[1].len = sizeof(response);
esm_info_resp.protocol_cnfg_opts.N_opts = 2;
} else {
esm_info_resp.protocol_cnfg_opts_present = false;
}
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (!pdu) {
nas_log->error("Fatal Error: Couldn't allocate PDU in %s.\n", __FUNCTION__);
return;
}
if (liblte_mme_pack_esm_information_response_msg(
&esm_info_resp, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get()) != LIBLTE_SUCCESS) {
nas_log->error("Error packing ESM information response.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info_hex(pdu->msg, pdu->N_bytes, "Sending ESM information response\n");
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
chap_id++;
}
void nas::send_activate_dedicated_eps_bearer_context_accept(const uint8_t& proc_transaction_id,
const uint8_t& eps_bearer_id)
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
LIBLTE_MME_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT accept = {};
accept.eps_bearer_id = eps_bearer_id;
accept.proc_transaction_id = proc_transaction_id;
if (liblte_mme_pack_activate_dedicated_eps_bearer_context_accept_msg(
&accept, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get()) != LIBLTE_SUCCESS) {
nas_log->error("Error packing Activate Dedicated EPS Bearer context accept.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info_hex(pdu->msg,
pdu->N_bytes,
"Sending Activate Dedicated EPS Bearer context accept (eps_bearer_id=%d, proc_id=%d)\n",
accept.eps_bearer_id,
accept.proc_transaction_id);
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_deactivate_eps_bearer_context_accept(const uint8_t& proc_transaction_id, const uint8_t& eps_bearer_id)
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
LIBLTE_MME_DEACTIVATE_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT accept = {};
accept.eps_bearer_id = eps_bearer_id;
accept.proc_transaction_id = proc_transaction_id;
if (liblte_mme_pack_deactivate_eps_bearer_context_accept_msg(
&accept, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get()) != LIBLTE_SUCCESS) {
nas_log->error("Error packing Activate EPS Bearer context accept.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info_hex(pdu->msg,
pdu->N_bytes,
"Sending Deactivate EPS Bearer context accept (eps_bearer_id=%d, proc_id=%d)\n",
accept.eps_bearer_id,
accept.proc_transaction_id);
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_modify_eps_bearer_context_accept(const uint8_t& proc_transaction_id, const uint8_t& eps_bearer_id)
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
LIBLTE_MME_MODIFY_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT accept = {};
accept.eps_bearer_id = eps_bearer_id;
accept.proc_transaction_id = proc_transaction_id;
if (liblte_mme_pack_modify_eps_bearer_context_accept_msg(
&accept, current_sec_hdr, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)pdu.get()) != LIBLTE_SUCCESS) {
nas_log->error("Error packing Modify EPS Bearer context accept.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info_hex(pdu->msg,
pdu->N_bytes,
"Sending Modify EPS Bearer context accept (eps_bearer_id=%d, proc_id=%d)\n",
accept.eps_bearer_id,
accept.proc_transaction_id);
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_activate_test_mode_complete()
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (liblte_mme_pack_activate_test_mode_complete_msg(
(LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), current_sec_hdr, ctxt.tx_count)) {
nas_log->error("Error packing activate test mode complete.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info_hex(pdu->msg, pdu->N_bytes, "Sending Activate test mode complete\n");
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
void nas::send_close_ue_test_loop_complete()
{
unique_byte_buffer_t pdu = srslte::allocate_unique_buffer(*pool, true);
if (liblte_mme_pack_close_ue_test_loop_complete_msg(
(LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), current_sec_hdr, ctxt.tx_count)) {
nas_log->error("Error packing close UE test loop complete.\n");
return;
}
if (pcap != nullptr) {
pcap->write_nas(pdu->msg, pdu->N_bytes);
}
if (apply_security_config(pdu, current_sec_hdr)) {
nas_log->error("Error applying NAS security.\n");
return;
}
nas_log->info_hex(pdu->msg, pdu->N_bytes, "Sending Close UE test loop complete\n");
rrc->write_sdu(std::move(pdu));
ctxt.tx_count++;
}
/*
* Handles the airplane mode simulation by triggering a UE switch off/on
* in user-definable time intervals
*/
void nas::handle_airplane_mode_sim()
{
if (cfg.sim.airplane_t_on_ms > 0 && airplane_mode_state == DISABLED) {
// check if we're already attached, if so, schedule airplane mode command
if (state == EMM_STATE_REGISTERED) {
// NAS is attached
task_sched.defer_callback(cfg.sim.airplane_t_on_ms, [&]() {
// Enabling air-plane mode
send_detach_request(true);
airplane_mode_state = ENABLED;
});
}
} else if (cfg.sim.airplane_t_off_ms > 0 && airplane_mode_state == ENABLED) {
// check if we are already deregistered, if so, schedule command to turn off airplone mode again
if (state == EMM_STATE_DEREGISTERED) {
// NAS is deregistered
task_sched.defer_callback(cfg.sim.airplane_t_off_ms, [&]() {
// Disabling airplane mode again
start_attach_proc(nullptr, srslte::establishment_cause_t::mo_sig);
airplane_mode_state = DISABLED;
});
}
}
// schedule another call
if (cfg.sim.airplane_t_on_ms > 0 || cfg.sim.airplane_t_off_ms > 0) {
task_sched.defer_callback(1000, [&]() { handle_airplane_mode_sim(); });
}
}
/*******************************************************************************
* Security context persistence file
******************************************************************************/
bool nas::read_ctxt_file(nas_sec_ctxt* ctxt_)
{
std::ifstream file;
if (ctxt_ == nullptr) {
return false;
}
if (cfg.force_imsi_attach) {
nas_log->info("Skip reading context from file.\n");
return false;
}
file.open(".ctxt", std::ios::in);
if (file.is_open()) {
if (!readvar(file, "m_tmsi=", &ctxt_->guti.m_tmsi)) {
return false;
}
if (!readvar(file, "mcc=", &ctxt_->guti.mcc)) {
return false;
}
if (!readvar(file, "mnc=", &ctxt_->guti.mnc)) {
return false;
}
if (!readvar(file, "mme_group_id=", &ctxt_->guti.mme_group_id)) {
return false;
}
if (!readvar(file, "mme_code=", &ctxt_->guti.mme_code)) {
return false;
}
if (!readvar(file, "tx_count=", &ctxt_->tx_count)) {
return false;
}
if (!readvar(file, "rx_count=", &ctxt_->rx_count)) {
return false;
}
if (!readvar(file, "int_alg=", &ctxt_->integ_algo)) {
return false;
}
if (!readvar(file, "enc_alg=", &ctxt_->cipher_algo)) {
return false;
}
if (!readvar(file, "ksi=", &ctxt_->ksi)) {
return false;
}
if (!readvar(file, "k_asme=", ctxt_->k_asme, 32)) {
return false;
}
file.close();
nas_log->info("Read GUTI from file "
"m_tmsi: %x, mcc: %x, mnc: %x, mme_group_id: %x, mme_code: %x\n",
ctxt_->guti.m_tmsi,
ctxt_->guti.mcc,
ctxt_->guti.mnc,
ctxt_->guti.mme_group_id,
ctxt_->guti.mme_code);
nas_log->info("Read security ctxt from file .ctxt. "
"ksi: %x, k_asme: %s, tx_count: %x, rx_count: %x, int_alg: %d, enc_alg: %d\n",
ctxt_->ksi,
hex_to_string(ctxt_->k_asme, 32).c_str(),
ctxt_->tx_count,
ctxt_->rx_count,
ctxt_->integ_algo,
ctxt_->cipher_algo);
have_guti = true;
have_ctxt = true;
current_sec_hdr = LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED;
return true;
}
return false;
}
bool nas::write_ctxt_file(nas_sec_ctxt ctxt_)
{
if (!have_guti || !have_ctxt) {
return false;
}
std::ofstream file;
file.open(".ctxt", std::ios::out | std::ios::trunc);
if (file.is_open()) {
file << "m_tmsi=" << (int)ctxt_.guti.m_tmsi << std::endl;
file << "mcc=" << (int)ctxt_.guti.mcc << std::endl;
file << "mnc=" << (int)ctxt_.guti.mnc << std::endl;
file << "mme_group_id=" << (int)ctxt_.guti.mme_group_id << std::endl;
file << "mme_code=" << (int)ctxt_.guti.mme_code << std::endl;
file << "tx_count=" << (int)ctxt_.tx_count << std::endl;
file << "rx_count=" << (int)ctxt_.rx_count << std::endl;
file << "int_alg=" << (int)ctxt_.integ_algo << std::endl;
file << "enc_alg=" << (int)ctxt_.cipher_algo << std::endl;
file << "ksi=" << (int)ctxt_.ksi << std::endl;
file << "k_asme=" << hex_to_string(ctxt_.k_asme, 32) << std::endl;
nas_log->info("Saved GUTI to file "
"m_tmsi: %x, mcc: %x, mnc: %x, mme_group_id: %x, mme_code: %x\n",
ctxt_.guti.m_tmsi,
ctxt_.guti.mcc,
ctxt_.guti.mnc,
ctxt_.guti.mme_group_id,
ctxt_.guti.mme_code);
nas_log->info("Saved security ctxt to file .ctxt. "
"ksi: %x, k_asme: %s, tx_count: %x, rx_count: %x, int_alg: %d, enc_alg: %d\n",
ctxt_.ksi,
hex_to_string(ctxt_.k_asme, 32).c_str(),
ctxt_.tx_count,
ctxt_.rx_count,
ctxt_.integ_algo,
ctxt_.cipher_algo);
file.close();
return true;
}
return false;
}
/*********************************************************************
* Conversion helpers
********************************************************************/
std::string nas::hex_to_string(uint8_t* hex, int size)
{
std::stringstream ss;
ss << std::hex << std::setfill('0');
for (int i = 0; i < size; i++) {
ss << std::setw(2) << static_cast<unsigned>(hex[i]);
}
return ss.str();
}
bool nas::string_to_hex(std::string hex_str, uint8_t* hex, uint32_t len)
{
static const char* const lut = "0123456789abcdef";
uint32_t str_len = hex_str.length();
if (str_len & 1) {
return false; // uneven hex_str length
}
if (str_len > len * 2) {
return false; // not enough space in hex buffer
}
for (uint32_t i = 0; i < str_len; i += 2) {
char a = hex_str[i];
const char* p = std::lower_bound(lut, lut + 16, a);
if (*p != a) {
return false; // invalid char
}
char b = hex_str[i + 1];
const char* q = std::lower_bound(lut, lut + 16, b);
if (*q != b) {
return false; // invalid char
}
hex[i / 2] = ((p - lut) << 4u) | (q - lut);
}
return true;
}
std::string nas::emm_info_str(LIBLTE_MME_EMM_INFORMATION_MSG_STRUCT* info)
{
std::stringstream ss;
if (info->full_net_name_present) {
ss << info->full_net_name.name;
}
if (info->short_net_name_present) {
ss << " (" << info->short_net_name.name << ")";
}
if (info->utc_and_local_time_zone_present) {
ss << " " << (int)info->utc_and_local_time_zone.day;
ss << "/" << (int)info->utc_and_local_time_zone.month;
ss << "/" << (int)info->utc_and_local_time_zone.year;
ss << " " << (int)info->utc_and_local_time_zone.hour;
ss << ":" << (int)info->utc_and_local_time_zone.minute;
ss << ":" << (int)info->utc_and_local_time_zone.second;
ss << " TZ:" << (int)info->utc_and_local_time_zone.tz;
}
return ss.str();
}
} // namespace srsue
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