/* * 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/interfaces/ue_interfaces.h" #include "srsue/hdr/stack/upper/nas_common.h" #include "srsue/hdr/stack/upper/nas_metrics.h" using srslte::byte_buffer_t; namespace srsue { class nas : public nas_interface_rrc, public nas_interface_ue, public srslte::timer_callback { public: explicit nas(srslte::task_handler_interface* task_handler_); void init(usim_interface_nas* usim_, rrc_interface_nas* rrc_, gw_interface_nas* gw_, const nas_args_t& args_); void stop(); void run_tti(); void get_metrics(nas_metrics_t* m); emm_state_t get_state(); // RRC interface void left_rrc_connected() 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 is_attached() 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; // UE interface void start_attach_proc(srslte::proc_state_t* result, srslte::establishment_cause_t cause_) final; bool detach_request(const bool switch_off) final; void plmn_search_completed(const rrc_interface_nas::found_plmn_t found_plmns[rrc_interface_nas::MAX_FOUND_PLMNS], int nof_plmns) final; bool connection_request_completed(bool outcome) final; // timer callback void timer_expired(uint32_t timeout_id) override; // PCAP void start_pcap(srslte::nas_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; nas_args_t cfg = {}; emm_state_t state = EMM_STATE_DEREGISTERED; srslte::barring_t current_barring = srslte::barring_t::none; bool plmn_is_selected = false; srslte::plmn_id_t current_plmn; srslte::plmn_id_t home_plmn; std::vector 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 eps_bearer_map_t; typedef std::pair 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_handler_interface* task_handler = nullptr; 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 = {}; // PCAP srslte::nas_pcap* pcap = nullptr; bool running = false; 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); 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(); // Other internal helpers void enter_state(emm_state_t state_); void handle_airplane_mode_sim(); void enter_emm_deregistered(); // 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 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 split_string(const std::string input) { std::vector 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; } class rrc_connect_proc { public: using rrc_connect_complete_ev = srslte::proc_state_t; struct connection_request_completed_t { bool outcome; }; struct attach_timeout { }; explicit rrc_connect_proc(nas* nas_ptr_); srslte::proc_outcome_t init(srslte::establishment_cause_t cause_, srslte::unique_byte_buffer_t pdu); srslte::proc_outcome_t step(); void then(const srslte::proc_state_t& result); srslte::proc_outcome_t react(connection_request_completed_t event); srslte::proc_outcome_t react(attach_timeout event); static const char* name() { return "RRC Connect"; } private: static const uint32_t attach_timeout_ms = 5000; nas* nas_ptr; srslte::timer_handler::unique_timer timeout_timer; enum class state_t { conn_req, wait_attach } state; }; class plmn_search_proc { public: struct plmn_search_complete_t { rrc_interface_nas::found_plmn_t found_plmns[rrc_interface_nas::MAX_FOUND_PLMNS]; int nof_plmns; plmn_search_complete_t(const rrc_interface_nas::found_plmn_t* plmns_, int nof_plmns_) : nof_plmns(nof_plmns_) { if (nof_plmns > 0) { std::copy(&plmns_[0], &plmns_[nof_plmns], found_plmns); } } }; explicit plmn_search_proc(nas* nas_ptr_) : nas_ptr(nas_ptr_) {} srslte::proc_outcome_t init(); srslte::proc_outcome_t step(); void then(const srslte::proc_state_t& result); srslte::proc_outcome_t react(const plmn_search_complete_t& t); srslte::proc_outcome_t react(const rrc_connect_proc::rrc_connect_complete_ev& t); static const char* name() { return "PLMN Search"; } private: nas* nas_ptr; enum class state_t { plmn_search, rrc_connect } state; }; srslte::proc_manager_list_t callbacks; srslte::proc_t plmn_searcher; srslte::proc_t rrc_connector; const std::string gw_setup_failure_str = "Failed to setup/configure GW interface"; }; } // namespace srsue #endif // SRSUE_NAS_H