/** * 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 SRSENB_S1AP_H #define SRSENB_S1AP_H #include #include "srsenb/hdr/common/common_enb.h" #include "srsran/adt/circular_map.h" #include "srsran/common/buffer_pool.h" #include "srsran/common/common.h" #include "srsran/common/s1ap_pcap.h" #include "srsran/common/threads.h" #include "srsran/interfaces/enb_interfaces.h" #include "srsran/interfaces/enb_s1ap_interfaces.h" #include "s1ap_metrics.h" #include "srsran/adt/optional.h" #include "srsran/asn1/s1ap.h" #include "srsran/common/network_utils.h" #include "srsran/common/stack_procedure.h" #include "srsran/common/task_scheduler.h" #include "srsran/srslog/srslog.h" #include namespace srsenb { class rrc_interface_s1ap; struct ue_ctxt_t { static const uint32_t invalid_enb_id = std::numeric_limits::max(); uint16_t rnti = SRSRAN_INVALID_RNTI; uint32_t enb_ue_s1ap_id = invalid_enb_id; srsran::optional mme_ue_s1ap_id; uint32_t enb_cc_idx = 0; struct timeval init_timestamp = {}; }; class s1ap : public s1ap_interface_rrc { using s1ap_proc_id_t = asn1::s1ap::s1ap_elem_procs_o::init_msg_c::types_opts::options; public: using erab_id_list = srsran::bounded_vector; using erab_item_list = srsran::bounded_vector; s1ap(srsran::task_sched_handle task_sched_, srslog::basic_logger& logger, srsran::socket_manager_itf* rx_socket_handler); int init(const s1ap_args_t& args_, rrc_interface_s1ap* rrc_); void stop(); void get_metrics(s1ap_metrics_t& m); // RRC interface void initial_ue(uint16_t rnti, uint32_t enb_cc_idx, asn1::s1ap::rrc_establishment_cause_e cause, srsran::unique_byte_buffer_t pdu) override; void initial_ue(uint16_t rnti, uint32_t enb_cc_idx, asn1::s1ap::rrc_establishment_cause_e cause, srsran::unique_byte_buffer_t pdu, uint32_t m_tmsi, uint8_t mmec) override; void write_pdu(uint16_t rnti, srsran::unique_byte_buffer_t pdu) override; bool user_exists(uint16_t rnti) override; void user_mod(uint16_t old_rnti, uint16_t new_rnti) override; bool user_release(uint16_t rnti, asn1::s1ap::cause_radio_network_e cause_radio) override; void notify_rrc_reconf_complete(uint16_t rnti) override; bool is_mme_connected() override; bool send_ho_required(uint16_t rnti, uint32_t target_eci, uint16_t target_tac, srsran::plmn_id_t target_plmn, srsran::span fwd_erabs, srsran::unique_byte_buffer_t rrc_container, bool has_direct_fwd_path) override; bool send_enb_status_transfer_proc(uint16_t rnti, std::vector& bearer_status_list) override; bool send_ho_req_ack(const asn1::s1ap::ho_request_s& msg, uint16_t rnti, uint32_t enb_cc_idx, srsran::unique_byte_buffer_t ho_cmd, srsran::span admitted_bearers, srsran::const_span not_admitted_bearers) override; void send_ho_cancel(uint16_t rnti, const asn1::s1ap::cause_c& cause) override; bool release_erabs(uint16_t rnti, const std::vector& erabs_successfully_released) override; bool send_error_indication(const asn1::s1ap::cause_c& cause, srsran::optional enb_ue_s1ap_id = {}, srsran::optional mme_ue_s1ap_id = {}); bool send_ue_cap_info_indication(uint16_t rnti, srsran::unique_byte_buffer_t ue_radio_cap) override; /// Target eNB Handover /// Section 8.4.2 - Handover Resource Allocation void send_ho_failure(uint32_t mme_ue_s1ap_id, const asn1::s1ap::cause_c& cause); /// Section 8.4.3 - Handover Notification void send_ho_notify(uint16_t rnti, uint64_t target_eci) override; // Stack interface bool handle_mme_rx_msg(srsran::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags); void start_pcap(srsran::s1ap_pcap* pcap_); private: static const int MME_PORT = 36412; static const int ADDR_FAMILY = AF_INET; static const int SOCK_TYPE = SOCK_STREAM; static const int PROTO = IPPROTO_SCTP; static const int PPID = 18; static const int NONUE_STREAM_ID = 0; // args rrc_interface_s1ap* rrc = nullptr; s1ap_args_t args; srslog::basic_logger& logger; srslog::log_channel& alarms_channel; srsran::task_sched_handle task_sched; srsran::task_queue_handle mme_task_queue; srsran::socket_manager_itf* rx_socket_handler; srsran::unique_socket mme_socket; struct sockaddr_in mme_addr = {}; // MME address bool mme_connected = false; bool running = false; uint32_t next_enb_ue_s1ap_id = 1; // Next ENB-side UE identifier uint16_t next_ue_stream_id = 1; // Next UE SCTP stream identifier srsran::unique_timer mme_connect_timer, s1setup_timeout; // Protocol IEs sent with every UL S1AP message asn1::s1ap::tai_s tai; asn1::s1ap::eutran_cgi_s eutran_cgi; // PCAP srsran::s1ap_pcap* pcap = nullptr; asn1::s1ap::s1_setup_resp_s s1setupresponse; void build_tai_cgi(); bool connect_mme(); bool setup_s1(); bool sctp_send_s1ap_pdu(const asn1::s1ap::s1ap_pdu_c& tx_pdu, uint32_t rnti, const char* procedure_name); bool handle_s1ap_rx_pdu(srsran::byte_buffer_t* pdu); bool handle_initiatingmessage(const asn1::s1ap::init_msg_s& msg); bool handle_successfuloutcome(const asn1::s1ap::successful_outcome_s& msg); bool handle_unsuccessfuloutcome(const asn1::s1ap::unsuccessful_outcome_s& msg); bool handle_paging(const asn1::s1ap::paging_s& msg); bool handle_s1setupresponse(const asn1::s1ap::s1_setup_resp_s& msg); bool handle_dlnastransport(const asn1::s1ap::dl_nas_transport_s& msg); bool handle_initialctxtsetuprequest(const asn1::s1ap::init_context_setup_request_s& msg); bool handle_uectxtreleasecommand(const asn1::s1ap::ue_context_release_cmd_s& msg); bool handle_s1setupfailure(const asn1::s1ap::s1_setup_fail_s& msg); bool handle_erabsetuprequest(const asn1::s1ap::erab_setup_request_s& msg); bool handle_erabmodifyrequest(const asn1::s1ap::erab_modify_request_s& msg); bool handle_erabreleasecommand(const asn1::s1ap::erab_release_cmd_s& msg); bool handle_uecontextmodifyrequest(const asn1::s1ap::ue_context_mod_request_s& msg); void ue_ctxt_setup_complete(uint16_t rnti); // handover /** * Source eNB Handler for S1AP "HANDOVER PREPARATION FAILURE" Message * MME ---> Source eNB * @remark TS 36.413, 8.4.1.3 - S1AP Procedures | Handover Signalling | Handover Preparation | Unsuccessful Operation * @param msg HANDOVER COMMAND S1AP PDU * @return true if the HANDOVER COMMAND content is valid. False otherwise */ bool handle_handover_preparation_failure(const asn1::s1ap::ho_prep_fail_s& msg); /** * Source eNB Handler for S1AP "HANDOVER COMMAND" Message * MME ---> Source eNB * @remark TS 36.413, 8.4.1.2 - S1AP Procedures | Handover Signalling | Handover Preparation | Successful Operation * @param msg HANDOVER COMMAND S1AP PDU * @return true if the HANDOVER COMMAND content is valid. False otherwise */ bool handle_handover_command(const asn1::s1ap::ho_cmd_s& msg); /** * Target eNB Handler for S1AP "HANDOVER REQUEST" Message * MME ---> Target eNB * @remark TS 36.413, 8.4.7.2 - S1AP Procedures | Handover Signalling | Handover Resource Allocation * @param msg HANDOVER REQUEST S1AP PDU * @return true if the new user resources were successfully allocated */ bool handle_handover_request(const asn1::s1ap::ho_request_s& msg); /** * Target eNB Handler for S1AP "MME STATUS TRANSFER" Message * MME ---> Target eNB * @remark TS 36.413, 8.4.7.2 - S1AP Procedures | Handover Signalling | MME Status Transfer | Successful Operation * @param msg MME STATUS TRANSFER S1AP PDU * @return true if the msg content is valid. False otherwise */ bool handle_mme_status_transfer(const asn1::s1ap::mme_status_transfer_s& msg); // UE-specific data and procedures struct ue { //! TS 36.413, Section 8.4.1 - Handover Preparation Procedure class ho_prep_proc_t { public: struct ts1_reloc_prep_expired {}; ho_prep_proc_t(s1ap::ue* ue_); srsran::proc_outcome_t init(uint32_t target_eci_, uint16_t target_tac_, srsran::plmn_id_t target_plmn_, srsran::span fwd_erabs, srsran::unique_byte_buffer_t rrc_container, bool has_direct_fwd_path); srsran::proc_outcome_t step() { return srsran::proc_outcome_t::yield; } srsran::proc_outcome_t react(ts1_reloc_prep_expired e); srsran::proc_outcome_t react(const asn1::s1ap::ho_prep_fail_s& msg); srsran::proc_outcome_t react(const asn1::s1ap::ho_cmd_s& msg); void then(const srsran::proc_state_t& result); const char* name() { return "HandoverPreparation"; } private: s1ap::ue* ue_ptr = nullptr; s1ap* s1ap_ptr = nullptr; uint32_t target_eci = 0; uint16_t target_tac = 0; srsran::plmn_id_t target_plmn; srsran::unique_byte_buffer_t rrc_container; const asn1::s1ap::ho_cmd_s* ho_cmd_msg = nullptr; }; explicit ue(s1ap* s1ap_ptr_); bool send_enb_status_transfer_proc(std::vector& bearer_status_list); bool send_ulnastransport(srsran::unique_byte_buffer_t pdu); bool send_uectxtreleaserequest(const asn1::s1ap::cause_c& cause); bool send_uectxtmodifyfailure(const asn1::s1ap::cause_c& cause); bool send_uectxtmodifyresp(); bool send_uectxtreleasecomplete(); bool send_initialuemessage(asn1::s1ap::rrc_establishment_cause_e cause, srsran::unique_byte_buffer_t pdu, bool has_tmsi, uint32_t m_tmsi = 0, uint8_t mmec = 0); void ue_ctxt_setup_complete(); void notify_rrc_reconf_complete(); bool send_erab_setup_response(const erab_id_list& erabs_setup, const erab_item_list& erabs_failed); bool send_erab_release_response(const erab_id_list& erabs_released, const erab_item_list& erabs_failed); bool send_erab_modify_response(const erab_id_list& erabs_modified, const erab_item_list& erabs_failed); bool send_erab_release_indication(const std::vector& erabs_successfully_released); bool send_ue_cap_info_indication(srsran::unique_byte_buffer_t ue_radio_cap); /// TS 36.413 8.4.5 - Handover Cancellation void send_ho_cancel(const asn1::s1ap::cause_c& cause); bool was_uectxtrelease_requested() const { return release_requested; } void set_state(s1ap_proc_id_t state, const erab_id_list& erabs_updated, const erab_item_list& erabs_failed_to_update); s1ap_proc_id_t get_state() const { return current_state; } ue_ctxt_t ctxt = {}; uint16_t stream_id = 1; private: bool send_ho_required(uint32_t target_eci_, uint16_t target_tac_, srsran::plmn_id_t target_plmn_, srsran::span fwd_erabs, srsran::unique_byte_buffer_t rrc_container, bool has_direct_fwd_path); void get_erab_addr(uint16_t erab_id, transp_addr_t& transp_addr, asn1::fixed_octstring<4, true>& gtpu_teid_id); // args s1ap* s1ap_ptr; srslog::basic_logger& logger; // state bool release_requested = false; srsran::unique_timer ts1_reloc_prep; ///< TS1_{RELOCprep} - max time for HO preparation srsran::unique_timer ts1_reloc_overall; ///< TS1_{RELOCOverall} srsran::unique_timer overall_procedure_timeout; // Procedure state s1ap_proc_id_t current_state = s1ap_proc_id_t::nulltype; erab_id_list updated_erabs; srsran::bounded_vector failed_cfg_erabs; public: // user procedures srsran::proc_t ho_prep_proc; }; class user_list { public: using value_type = std::unique_ptr; using iterator = std::unordered_map::iterator; using const_iterator = std::unordered_map::const_iterator; using pair_type = std::unordered_map::value_type; ue* find_ue_rnti(uint16_t rnti); ue* find_ue_enbid(uint32_t enbid); ue* find_ue_mmeid(uint32_t mmeid); ue* add_user(value_type user); void erase(ue* ue_ptr); iterator begin() { return users.begin(); } iterator end() { return users.end(); } const_iterator cbegin() const { return users.begin(); } const_iterator cend() const { return users.end(); } size_t size() const { return users.size(); } private: std::unordered_map > users; // maps ENB_S1AP_ID to user }; user_list users; // procedures class s1_setup_proc_t { public: struct s1setupresult { bool success = false; enum class cause_t { timeout, failure } cause; }; struct s1connectresult { bool success = false; }; explicit s1_setup_proc_t(s1ap* s1ap_) : s1ap_ptr(s1ap_) {} srsran::proc_outcome_t init(); srsran::proc_outcome_t step() { return srsran::proc_outcome_t::yield; } srsran::proc_outcome_t react(const s1connectresult& event); srsran::proc_outcome_t react(const s1setupresult& event); void then(const srsran::proc_state_t& result); const char* name() const { return "MME Connection"; } uint16_t connect_count = 0; private: srsran::proc_outcome_t start_mme_connection(); s1ap* s1ap_ptr = nullptr; }; ue* handle_s1apmsg_ue_id(uint32_t enb_id, uint32_t mme_id); std::string get_cause(const asn1::s1ap::cause_c& c); void log_s1ap_msg(const asn1::s1ap::s1ap_pdu_c& msg, srsran::const_span sdu, bool is_rx); srsran::proc_t s1setup_proc; }; } // namespace srsenb #endif // SRSENB_S1AP_H