/** * Copyright 2013-2022 Software Radio Systems Limited * * This file is part of srsRAN. * * srsRAN 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. * * srsRAN 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 SRSEPC_NAS_H #define SRSEPC_NAS_H #include "srsran/asn1/gtpc_ies.h" #include "srsran/asn1/liblte_mme.h" #include "srsran/common/buffer_pool.h" #include "srsran/common/security.h" #include "srsran/interfaces/epc_interfaces.h" #include "srsran/srslog/srslog.h" #include namespace srsepc { static const uint8_t MAX_ERABS_PER_UE = 16; // MME EMM states (3GPP 24.301 v10.0.0, section 5.1.3.4) typedef enum { EMM_STATE_DEREGISTERED = 0, EMM_STATE_COMMON_PROCEDURE_INITIATED, EMM_STATE_REGISTERED, EMM_STATE_DEREGISTERED_INITIATED, EMM_STATE_N_ITEMS, } emm_state_t; static const char emm_state_text[EMM_STATE_N_ITEMS][100] = {"DEREGISTERED", "COMMON PROCEDURE INITIATED", "REGISTERED", "DEREGISTERED INITIATED"}; // MME ECM states (3GPP 23.401 v10.0.0, section 4.6.3) typedef enum { ECM_STATE_IDLE = 0, ECM_STATE_CONNECTED, ECM_STATE_N_ITEMS, } ecm_state_t; static const char ecm_state_text[ECM_STATE_N_ITEMS][100] = {"IDLE", "CONNECTED"}; /* // MME ESM states (3GPP 23.401 v10.0.0, section 4.6.3) typedef enum { ESM_BEARER_CONTEXT_INACTIVE = 0, ESM_BEARER_CONTEXT_ACTIVE_PENDING, ESM_BEARER_CONTEXT_ACTIVE, ESM_BEARER_CONTEXT_INACTIVE_PENDING, ESM_BEARER_CONTEXT_MODIFY_PENDING, ESM_BEARER_PROCEDURE_TRANSACTION_INACTIVE, ESM_BEARER_PROCEDURE_TRANSACTION_PENDING, ESM_STATE_N_ITEMS, } esm_state_t; static const char esm_state_text[ESM_STATE_N_ITEMS][100] = {"CONTEXT INACTIVE", "CONTEXT ACTIVE PENDING", "CONTEXT ACTIVE", "CONTEXT_INACTIVE_PENDING", "CONTEXT_MODIFY_PENDING", "PROCEDURE_TRANSACTION_INACTIVE" "PROCEDURE_TRANSACTION_PENDING"}; */ typedef enum { ERAB_DEACTIVATED, ERAB_CTX_REQUESTED, ERAB_CTX_SETUP, ERAB_ACTIVE } esm_state_t; /* * EMM, ECM, ESM and EPS Security context definitions */ typedef struct { uint64_t imsi; emm_state_t state; uint8_t procedure_transaction_id; uint8_t attach_type; struct in_addr ue_ip; srsran::gtpc_f_teid_ie sgw_ctrl_fteid; } emm_ctx_t; typedef struct { ecm_state_t state; uint32_t enb_ue_s1ap_id; uint32_t mme_ue_s1ap_id; struct sctp_sndrcvinfo enb_sri; bool eit; } ecm_ctx_t; typedef struct { uint8_t erab_id; esm_state_t state; uint8_t qci; srsran::gtpc_f_teid_ie enb_fteid; srsran::gtpc_f_teid_ie sgw_s1u_fteid; srsran::gtpc_pdn_address_allocation_ie pdn_addr_alloc; } esm_ctx_t; typedef struct { uint8_t eksi; uint8_t k_asme[32]; uint8_t autn[16]; uint8_t rand[16]; uint8_t xres[16]; // minimum 6, maximum 16 uint32_t dl_nas_count; uint32_t ul_nas_count; srsran::CIPHERING_ALGORITHM_ID_ENUM cipher_algo; srsran::INTEGRITY_ALGORITHM_ID_ENUM integ_algo; uint8_t k_nas_enc[32]; uint8_t k_nas_int[32]; uint8_t k_enb[32]; LIBLTE_MME_UE_NETWORK_CAPABILITY_STRUCT ue_network_cap; bool ms_network_cap_present; LIBLTE_MME_MS_NETWORK_CAPABILITY_STRUCT ms_network_cap; LIBLTE_MME_EPS_MOBILE_ID_GUTI_STRUCT guti; } sec_ctx_t; /* * NAS Initialization Arguments */ typedef struct { uint16_t mcc; uint16_t mnc; uint8_t mme_code; uint16_t mme_group; uint16_t tac; uint16_t paging_timer; std::string apn; std::string dns; std::string full_net_name; std::string short_net_name; srsran::CIPHERING_ALGORITHM_ID_ENUM cipher_algo; srsran::INTEGRITY_ALGORITHM_ID_ENUM integ_algo; bool request_imeisv; uint16_t lac; } nas_init_t; typedef struct { s1ap_interface_nas* s1ap; gtpc_interface_nas* gtpc; hss_interface_nas* hss; mme_interface_nas* mme; } nas_if_t; class nas { public: nas(const nas_init_t& args, const nas_if_t& itf); void reset(); /*********************** * Initial UE messages * ***********************/ // Attach request messages static bool handle_attach_request(uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, srsran::byte_buffer_t* nas_rx, const nas_init_t& args, const nas_if_t& itf); static bool handle_imsi_attach_request_unknown_ue(uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT& attach_req, const LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT& pdn_con_req, const nas_init_t& args, const nas_if_t& itf); static bool handle_imsi_attach_request_known_ue(nas* nas_ctx, uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT& attach_req, const LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT& pdn_con_req, srsran::byte_buffer_t* nas_rx, const nas_init_t& args, const nas_if_t& itf); static bool handle_guti_attach_request_unknown_ue(uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT& attach_req, const LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT& pdn_con_req, const nas_init_t& args, const nas_if_t& itf); static bool handle_guti_attach_request_known_ue(nas* nas_ctx, uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT& attach_req, const LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT& pdn_con_req, srsran::byte_buffer_t* nas_rx, const nas_init_t& args, const nas_if_t& itf); // Service request messages static bool handle_service_request(uint32_t m_tmsi, uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, srsran::byte_buffer_t* nas_rx, const nas_init_t& args, const nas_if_t& itf); // Dettach request messages static bool handle_detach_request(uint32_t m_tmsi, uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, srsran::byte_buffer_t* nas_rx, const nas_init_t& args, const nas_if_t& itf); // Tracking area update request messages static bool handle_tracking_area_update_request(uint32_t m_tmsi, uint32_t enb_ue_s1ap_id, struct sctp_sndrcvinfo* enb_sri, srsran::byte_buffer_t* nas_rx, const nas_init_t& args, const nas_if_t& itf); /* Uplink NAS messages handling */ bool handle_attach_request(srsran::byte_buffer_t* nas_rx); bool handle_pdn_connectivity_request(srsran::byte_buffer_t* nas_rx); bool handle_authentication_response(srsran::byte_buffer_t* nas_rx); bool handle_security_mode_complete(srsran::byte_buffer_t* nas_rx); bool handle_attach_complete(srsran::byte_buffer_t* nas_rx); bool handle_esm_information_response(srsran::byte_buffer_t* nas_rx); bool handle_identity_response(srsran::byte_buffer_t* nas_rx); bool handle_tracking_area_update_request(srsran::byte_buffer_t* nas_rx); bool handle_authentication_failure(srsran::byte_buffer_t* nas_rx); bool handle_detach_request(srsran::byte_buffer_t* nas_rx); /* Downlink NAS messages packing */ bool pack_authentication_request(srsran::byte_buffer_t* nas_buffer); bool pack_authentication_reject(srsran::byte_buffer_t* nas_buffer); bool pack_security_mode_command(srsran::byte_buffer_t* nas_buffer); bool pack_esm_information_request(srsran::byte_buffer_t* nas_buffer); bool pack_identity_request(srsran::byte_buffer_t* nas_buffer); bool pack_emm_information(srsran::byte_buffer_t* nas_buffer); bool pack_service_reject(srsran::byte_buffer_t* nas_buffer, uint8_t emm_cause); bool pack_tracking_area_update_reject(srsran::byte_buffer_t* nas_buffer, uint8_t emm_cause); bool pack_attach_accept(srsran::byte_buffer_t* nas_buffer); /* Security functions */ bool integrity_check(srsran::byte_buffer_t* pdu, bool warn_failure = true); bool short_integrity_check(srsran::byte_buffer_t* pdu); void integrity_generate(srsran::byte_buffer_t* pdu, uint8_t* mac); void cipher_decrypt(srsran::byte_buffer_t* pdu); void cipher_encrypt(srsran::byte_buffer_t* pdu); /*Timer functions*/ bool start_timer(enum nas_timer_type type); bool expire_timer(enum nas_timer_type type); /* UE Context */ emm_ctx_t m_emm_ctx = {}; ecm_ctx_t m_ecm_ctx = {}; esm_ctx_t m_esm_ctx[MAX_ERABS_PER_UE] = {}; sec_ctx_t m_sec_ctx = {}; private: srslog::basic_logger& m_logger = srslog::fetch_basic_logger("NAS"); gtpc_interface_nas* m_gtpc = nullptr; s1ap_interface_nas* m_s1ap = nullptr; hss_interface_nas* m_hss = nullptr; mme_interface_nas* m_mme = nullptr; uint16_t m_mcc = 0; uint16_t m_mnc = 0; uint16_t m_mme_group = 0; uint16_t m_mme_code = 0; uint16_t m_tac = 0; std::string m_apn; std::string m_dns; std::string m_full_net_name; std::string m_short_net_name; bool m_request_imeisv = false; uint16_t m_lac = 0; // Timers timeout values uint16_t m_t3413 = 0; // Timer functions bool start_t3413(); bool expire_t3413(); }; } // namespace srsepc #endif // SRSEPC_NAS_H