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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/.
*
*/
#ifndef SRSUE_NAS_H
#define SRSUE_NAS_H
#include "srslte/asn1/liblte_mme.h"
#include "srslte/common/buffer_pool.h"
#include "srslte/common/common.h"
#include "srslte/common/logmap.h"
#include "srslte/common/nas_pcap.h"
#include "srslte/common/security.h"
#include "srslte/common/stack_procedure.h"
#include "srslte/common/task_scheduler.h"
#include "srslte/interfaces/ue_interfaces.h"
#include "srsue/hdr/stack/upper/nas_config.h"
#include "srsue/hdr/stack/upper/nas_emm_state.h"
#include "srsue/hdr/stack/upper/nas_metrics.h"
using srslte::byte_buffer_t;
namespace srsue {
class nas : public nas_interface_rrc, public srslte::timer_callback
{
public:
explicit nas(srslte::task_sched_handle task_sched_);
virtual ~nas();
void init(usim_interface_nas* usim_, rrc_interface_nas* rrc_, gw_interface_nas* gw_, const nas_args_t& args_);
void stop();
void run_tti();
// Metrics getter
void get_metrics(nas_metrics_t* m);
// RRC interface
void left_rrc_connected() override;
bool connection_request_completed(bool outcome) override;
bool paging(srslte::s_tmsi_t* ue_identity) override;
void set_barring(srslte::barring_t barring) override;
void write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu) override;
uint32_t get_k_enb_count() override;
bool get_k_asme(uint8_t* k_asme_, uint32_t n) override;
uint32_t get_ipv4_addr() override;
bool get_ipv6_addr(uint8_t* ipv6_addr) override;
void plmn_search_completed(const rrc_interface_nas::found_plmn_t found_plmns[rrc_interface_nas::MAX_FOUND_PLMNS],
int nof_plmns) final;
// Stack interface
bool switch_on();
bool switch_off();
bool enable_data();
bool disable_data();
void start_service_request(srslte::establishment_cause_t cause_);
// Stack+RRC interface
bool is_registered() override;
// timer callback
void timer_expired(uint32_t timeout_id) override;
// PCAP
void start_pcap(srslte::nas_pcap* pcap_) { pcap = pcap_; }
private:
srslte::byte_buffer_pool* pool = nullptr;
srslte::log_ref nas_log;
rrc_interface_nas* rrc = nullptr;
usim_interface_nas* usim = nullptr;
gw_interface_nas* gw = nullptr;
bool running = false;
nas_args_t cfg = {};
emm_state_t state = {};
srslte::barring_t current_barring = srslte::barring_t::none;
srslte::plmn_id_t current_plmn;
srslte::plmn_id_t home_plmn;
std::vector<srslte::plmn_id_t> known_plmns;
// Security context
struct nas_sec_ctxt {
uint8_t ksi;
uint8_t k_asme[32];
uint32_t tx_count;
uint32_t rx_count;
uint32_t k_enb_count;
srslte::CIPHERING_ALGORITHM_ID_ENUM cipher_algo;
srslte::INTEGRITY_ALGORITHM_ID_ENUM integ_algo;
LIBLTE_MME_EPS_MOBILE_ID_GUTI_STRUCT guti;
};
typedef enum { DEFAULT_EPS_BEARER = 0, DEDICATED_EPS_BEARER } eps_bearer_type_t;
typedef struct {
eps_bearer_type_t type;
uint8_t eps_bearer_id;
uint8_t linked_eps_bearer_id;
} eps_bearer_t;
typedef std::map<uint8_t, eps_bearer_t> eps_bearer_map_t;
typedef std::pair<uint8_t, eps_bearer_t> eps_bearer_map_pair_t;
eps_bearer_map_t eps_bearer;
bool have_guti = false;
bool have_ctxt = false;
nas_sec_ctxt ctxt = {};
bool auth_request = false;
uint8_t current_sec_hdr = LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS;
const uint32_t max_attach_attempts = 5; // Sec. 5.5.1.2.6
uint32_t attach_attempt_counter = 0;
uint32_t ip_addr = 0;
uint8_t ipv6_if_id[8] = {};
uint8_t chap_id = 0;
uint8_t transaction_id = 0;
// timers
srslte::task_sched_handle task_sched;
srslte::timer_handler::unique_timer t3402; // started when attach attempt counter reached 5
srslte::timer_handler::unique_timer t3410; // started when attach request is sent, on expiry, start t3411
srslte::timer_handler::unique_timer t3411; // started when attach failed
srslte::timer_handler::unique_timer t3421; // started when detach request is sent
srslte::timer_handler::unique_timer reattach_timer; // started to trigger delayed re-attach
// Values according to TS 24.301 Sec 10.2
const uint32_t t3402_duration_ms = 12 * 60 * 1000; // 12m
const uint32_t t3410_duration_ms = 15 * 1000; // 15s
const uint32_t t3411_duration_ms = 10 * 1000; // 10s
const uint32_t t3421_duration_ms = 15 * 1000; // 15s
const uint32_t reattach_timer_duration_ms = 2 * 1000; // 2s (arbitrarily chosen to delay re-attach)
// TS 23.003 Sec. 6.2.2 IMEISV's last two octets are Software Version Number (SVN)
// which identifies the software version number of the mobile equipment
const uint8_t ue_svn_oct1 = 0x5;
const uint8_t ue_svn_oct2 = 0x3;
// Security
bool eia_caps[8] = {};
bool eea_caps[8] = {};
uint8_t k_nas_enc[32] = {};
uint8_t k_nas_int[32] = {};
// Airplane mode simulation
typedef enum { DISABLED = 0, ENABLED } airplane_mode_state_t;
airplane_mode_state_t airplane_mode_state = {};
srslte::timer_handler::unique_timer airplane_mode_sim_timer;
// PCAP
srslte::nas_pcap* pcap = nullptr;
// Security
void
integrity_generate(uint8_t* key_128, uint32_t count, uint8_t direction, uint8_t* msg, uint32_t msg_len, uint8_t* mac);
bool integrity_check(srslte::byte_buffer_t* pdu);
void cipher_encrypt(srslte::byte_buffer_t* pdu);
void cipher_decrypt(srslte::byte_buffer_t* pdu);
int apply_security_config(srslte::unique_byte_buffer_t& pdu, uint8_t sec_hdr_type);
void reset_security_context();
void set_k_enb_count(uint32_t count);
bool check_cap_replay(LIBLTE_MME_UE_SECURITY_CAPABILITIES_STRUCT* caps);
// NAS Connection Initiation/Termination
void start_attach_request(srslte::establishment_cause_t cause_);
bool detach_request(const bool switch_off);
// PLMN Selection Helpers
void start_plmn_selection_proc();
void select_plmn();
// Parsers
void parse_attach_accept(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_attach_reject(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_authentication_request(uint32_t lcid, srslte::unique_byte_buffer_t pdu, const uint8_t sec_hdr_type);
void parse_authentication_reject(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_identity_request(srslte::unique_byte_buffer_t pdu, const uint8_t sec_hdr_type);
void parse_security_mode_command(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_service_reject(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_esm_information_request(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_emm_information(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_detach_request(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_emm_status(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_activate_dedicated_eps_bearer_context_request(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_deactivate_eps_bearer_context_request(srslte::unique_byte_buffer_t pdu);
void parse_activate_test_mode(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_close_ue_test_loop(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
void parse_modify_eps_bearer_context_request(srslte::unique_byte_buffer_t pdu);
// Packet generators
void gen_attach_request(srslte::unique_byte_buffer_t& msg);
void gen_service_request(srslte::unique_byte_buffer_t& msg);
// Senders
void send_attach_complete(const uint8_t& transaction_id, const uint8_t& eps_bearer_id);
void send_identity_response(uint8 id_type);
void send_service_request();
void send_esm_information_response(const uint8 proc_transaction_id);
void send_authentication_response(const uint8_t* res, const size_t res_len);
void send_authentication_failure(const uint8_t cause, const uint8_t* auth_fail_param);
void gen_pdn_connectivity_request(LIBLTE_BYTE_MSG_STRUCT* msg);
void send_security_mode_reject(uint8_t cause);
void send_attach_request();
void send_detach_request(bool switch_off);
void send_detach_accept();
void send_activate_dedicated_eps_bearer_context_accept(const uint8_t& proc_transaction_id,
const uint8_t& eps_bearer_id);
void send_deactivate_eps_bearer_context_accept(const uint8_t& proc_transaction_id, const uint8_t& eps_bearer_id);
void send_modify_eps_bearer_context_accept(const uint8_t& proc_transaction_id, const uint8_t& eps_bearer_id);
void send_activate_test_mode_complete();
void send_close_ue_test_loop_complete();
// Airplane mode simulator helpers
void start_airplane_mode_sim();
void airplane_mode_sim_switch_off();
void airplane_mode_sim_switch_on();
// FSM Helpers
void enter_state(emm_state_t state_);
void enter_emm_null();
void enter_emm_deregistered(emm_state_t::deregistered_substate_t substate);
void enter_emm_deregistered_initiated();
// security context persistence file
bool read_ctxt_file(nas_sec_ctxt* ctxt);
bool write_ctxt_file(nas_sec_ctxt ctxt_);
// ctxt file helpers
std::string hex_to_string(uint8_t* hex, int size);
bool string_to_hex(std::string hex_str, uint8_t* hex, uint32_t len);
std::string emm_info_str(LIBLTE_MME_EMM_INFORMATION_MSG_STRUCT* info);
template <class T>
bool readvar(std::istream& file, const char* key, T* var)
{
std::string line;
size_t len = strlen(key);
std::getline(file, line);
if (line.substr(0, len).compare(key)) {
return false;
}
*var = (T)strtol(line.substr(len).c_str(), NULL, 10);
return true;
}
bool readvar(std::istream& file, const char* key, uint8_t* var, int varlen)
{
std::string line;
size_t len = strlen(key);
std::getline(file, line);
if (line.substr(0, len).compare(key)) {
return false;
}
std::string tmp = line.substr(len);
if (!string_to_hex(tmp, var, varlen)) {
return false;
}
return true;
}
std::vector<uint8_t> split_string(const std::string input)
{
std::vector<uint8_t> list;
std::stringstream ss(input);
while (ss.good()) {
std::string substr;
getline(ss, substr, ',');
if (not substr.empty()) {
list.push_back(strtol(substr.c_str(), nullptr, 10));
}
}
return list;
}
// NAS Idle procedures
class plmn_search_proc; // PLMN selection proc (fwd declared)
srslte::proc_manager_list_t callbacks;
srslte::proc_t<plmn_search_proc> plmn_searcher;
const std::string gw_setup_failure_str = "Failed to setup/configure GW interface";
};
} // namespace srsue
#endif // SRSUE_NAS_H