Added deregistration (UE terminating)

lib/include/srsran/interfaces/gnb_rrc_nr_interfaces.h

@@ -29,6 +29,7 @@ public:
   virtual int
   establish_rrc_bearer(uint16_t rnti, uint16_t pdu_session_id, srsran::const_byte_span nas_pdu, uint32_t lcid) = 0;
   virtual int  allocate_lcid(uint16_t rnti)                                                                    = 0;
+  virtual int  release_bearers(uint16_t rnti)                                                                  = 0;
   virtual void write_dl_info(uint16_t rnti, srsran::unique_byte_buffer_t sdu)                                  = 0;
 };
 

srsenb/hdr/stack/ngap/ngap_interfaces.h

@@ -24,6 +24,7 @@ public:
                send_pdu_session_resource_setup_response(uint16_t                                    pdu_session_id,
                                                         uint32_t                                    teid_out,
                                                         asn1::bounded_bitstring<1, 160, true, true> transport_layer_address) = 0;
+  virtual bool send_ue_ctxt_release_complete() = 0;
 };
 } // namespace srsenb
 

srsenb/hdr/stack/ngap/ngap_ue.h

@@ -44,6 +44,8 @@ public:
   bool send_pdu_session_resource_setup_response(uint16_t                                    pdu_session_id,
                                                 uint32_t                                    teid_in,
                                                 asn1::bounded_bitstring<1, 160, true, true> addr_in);
+  // TS 38.413 - Section 9.2.1.2 - UE Context Release Complete
+  bool send_ue_ctxt_release_complete();
   // TS 38.413 - Section 9.2.2.1 - Initial Context Setup Request
   bool handle_initial_ctxt_setup_request(const asn1::ngap_nr::init_context_setup_request_s& msg);
   // TS 38.413 - Section 9.2.2.5 - UE Context Release Command

srsenb/hdr/stack/ngap/ngap_ue_bearer_manager.h

@@ -54,6 +54,8 @@ public:
                       uint32_t&                                          teid_in,
                       asn1::ngap_nr::cause_c&                            cause);
 
+  int reset_pdu_sessions(uint16_t rnti);
+
 private:
   gtpu_interface_rrc*              gtpu = nullptr;
   rrc_interface_ngap_nr*           rrc  = nullptr;

srsenb/hdr/stack/ngap/ngap_ue_proc.h

@@ -16,12 +16,12 @@
 #include "ngap_interfaces.h"
 #include "ngap_ue_utils.h"
 
+#include "srsenb/hdr/stack/ngap/ngap_ue_bearer_manager.h"
 #include "srsran/asn1/asn1_utils.h"
 #include "srsran/asn1/ngap.h"
 #include "srsran/common/buffer_pool.h"
 #include "srsran/common/stack_procedure.h"
 #include "srsran/interfaces/gnb_rrc_nr_interfaces.h"
-#include "srsenb/hdr/stack/ngap/ngap_ue_bearer_manager.h"
 
 #include <map>
 #include <string>
@@ -57,6 +57,7 @@ public:
   explicit ngap_ue_ue_context_release_proc(ngap_interface_ngap_proc* parent_,
                                            rrc_interface_ngap_nr*    rrc_,
                                            ngap_ue_ctxt_t*           ue_ctxt,
+                                           ngap_ue_bearer_manager*   bearer_manager,
                                            srslog::basic_logger&     logger_);
   srsran::proc_outcome_t init(const asn1::ngap_nr::ue_context_release_cmd_s& msg);
   srsran::proc_outcome_t step();
@@ -66,6 +67,7 @@ private:
   ngap_ue_ctxt_t*           ue_ctxt;
   ngap_interface_ngap_proc* parent         = nullptr;
   rrc_interface_ngap_nr*    rrc            = nullptr;
+  ngap_ue_bearer_manager*   bearer_manager = nullptr;
   srslog::basic_logger&     logger;
 };
 

srsenb/hdr/stack/rrc/rrc_nr.h

@@ -95,6 +95,7 @@ public:
   int  ue_set_security_cfg_capabilities(uint16_t rnti, const asn1::ngap_nr::ue_security_cap_s& caps);
   int  start_security_mode_procedure(uint16_t rnti);
   int  establish_rrc_bearer(uint16_t rnti, uint16_t pdu_session_id, srsran::const_byte_span nas_pdu, uint32_t lcid);
+  int  release_bearers(uint16_t rnti);
   void write_dl_info(uint16_t rnti, srsran::unique_byte_buffer_t sdu);
   int  set_aggregate_max_bitrate(uint16_t rnti, const asn1::ngap_nr::ue_aggregate_maximum_bit_rate_s& rates);
   int  allocate_lcid(uint16_t rnti);

srsenb/src/stack/ngap/ngap.cc

@@ -537,14 +537,21 @@ bool ngap::handle_initial_ctxt_setup_request(const asn1::ngap_nr::init_context_s
 
 bool ngap::handle_ue_ctxt_release_cmd(const asn1::ngap_nr::ue_context_release_cmd_s& msg)
 {
-  // TODO: UE Context Release Command contains a list of ue_ngap_ids
+  const asn1::ngap_nr::ue_ngap_id_pair_s& ue_ngap_id_pair = msg.protocol_ies.ue_ngap_ids.value.ue_ngap_id_pair();
+
+  ue* u = handle_ngapmsg_ue_id(ue_ngap_id_pair.ran_ue_ngap_id, ue_ngap_id_pair.amf_ue_ngap_id);
+  if (u == nullptr) {
+    logger.warning("Can not find UE");
+    return false;
+  }
+
+  u->handle_ue_ctxt_release_cmd(msg);
 
   return true;
 }
 
 bool ngap::handle_ue_pdu_session_res_setup_request(const asn1::ngap_nr::pdu_session_res_setup_request_s& msg)
 {
-  
   ue* u =
       handle_ngapmsg_ue_id(msg.protocol_ies.ran_ue_ngap_id.value.value, msg.protocol_ies.amf_ue_ngap_id.value.value);
   if (u == nullptr) {

srsenb/src/stack/ngap/ngap_ue.cc

@@ -31,7 +31,7 @@ ngap::ue::ue(ngap*                  ngap_ptr_,
   ngap_ptr(ngap_ptr_),
   bearer_manager(rrc_ptr_, gtpu_ptr_, logger_),
   initial_context_setup_proc(this, rrc_ptr_, &ctxt, logger_),
-  ue_context_release_proc(this, rrc_ptr_, &ctxt, logger_),
+  ue_context_release_proc(this, rrc_ptr_, &ctxt, &bearer_manager, logger_),
   ue_pdu_session_res_setup_proc(this, rrc_ptr_, &ctxt, &bearer_manager, logger_)
 {
   ctxt.ran_ue_ngap_id = ngap_ptr->next_gnb_ue_ngap_id++;
@@ -223,6 +223,30 @@ bool ngap::ue::send_pdu_session_resource_setup_response(uint16_t
   return ngap_ptr->sctp_send_ngap_pdu(tx_pdu, ctxt.rnti, "PDUSessionResourceSetupResponse");
 }
 
+bool ngap::ue::send_ue_ctxt_release_complete()
+{
+  if (not ngap_ptr->amf_connected) {
+    logger.warning("AMF not connected");
+    return false;
+  }
+
+  ngap_pdu_c tx_pdu;
+  tx_pdu.set_successful_outcome().load_info_obj(ASN1_NGAP_NR_ID_UE_CONTEXT_RELEASE);
+  ue_context_release_complete_s& container = tx_pdu.successful_outcome().value.ue_context_release_complete();
+
+  // userLocationInformationNR
+  container.protocol_ies.user_location_info.value.set_user_location_info_nr();
+  container.protocol_ies.user_location_info.value.user_location_info_nr().nr_cgi.nrcell_id = ngap_ptr->nr_cgi.nrcell_id;
+  container.protocol_ies.user_location_info.value.user_location_info_nr().nr_cgi.plmn_id   = ngap_ptr->nr_cgi.plmn_id;
+  container.protocol_ies.user_location_info.value.user_location_info_nr().tai.plmn_id      = ngap_ptr->tai.plmn_id;
+  container.protocol_ies.user_location_info.value.user_location_info_nr().tai.tac          = ngap_ptr->tai.tac;
+
+  container.protocol_ies.ran_ue_ngap_id.value = ctxt.ran_ue_ngap_id;
+  container.protocol_ies.amf_ue_ngap_id.value = ctxt.amf_ue_ngap_id.value();
+
+  return ngap_ptr->sctp_send_ngap_pdu(tx_pdu, ctxt.rnti, "UEContextReleaseComplete");
+}
+
 /*******************************************************************************
 /* NGAP message handler
 ********************************************************************************/

srsenb/src/stack/ngap/ngap_ue_bearer_manager.cc

@@ -61,6 +61,15 @@ int ngap_ue_bearer_manager::add_pdu_session(uint16_t
   return SRSRAN_SUCCESS;
 }
 
+int ngap_ue_bearer_manager::reset_pdu_sessions(uint16_t rnti)
+{
+  for (auto iter = pdu_session_list.begin(); iter != pdu_session_list.end(); iter++) {
+    auto pdu_session_id = iter->first;
+    rem_gtpu_bearer(pdu_session_id, rnti);
+  }
+  return true;
+}
+
 int ngap_ue_bearer_manager::add_gtpu_bearer(uint16_t                                    rnti,
                                             uint32_t                                    lcid,
                                             uint32_t                                    pdu_session_id,

srsenb/src/stack/ngap/ngap_ue_proc.cc

@@ -66,19 +66,23 @@ proc_outcome_t ngap_ue_initial_context_setup_proc::step()
 ngap_ue_ue_context_release_proc::ngap_ue_ue_context_release_proc(ngap_interface_ngap_proc* parent_,
                                                                  rrc_interface_ngap_nr*    rrc_,
                                                                  ngap_ue_ctxt_t*           ue_ctxt_,
+                                                                 ngap_ue_bearer_manager*   bearer_manager_,
                                                                  srslog::basic_logger&     logger_) :
   logger(logger_)
 {
   parent         = parent_;
   rrc            = rrc_;
   ue_ctxt        = ue_ctxt_;
+  bearer_manager = bearer_manager_;
 };
 
 proc_outcome_t ngap_ue_ue_context_release_proc::init(const asn1::ngap_nr::ue_context_release_cmd_s& msg)
 {
-  // ue_ngap_ids_c ue_ngap_ids = msg.protocol_ies.ue_ngap_ids.value;
-  // cause_c       cause       = msg.protocol_ies.cause.value;
   logger.info("Started %s", name());
+  // TODO: How to approach erasing users ?
+  bearer_manager->reset_pdu_sessions(ue_ctxt->rnti);
+  rrc->release_bearers(ue_ctxt->rnti);
+  parent->send_initial_ctxt_setup_response();
   return proc_outcome_t::success;
 }
 

srsenb/src/stack/rrc/rrc_nr.cc

@@ -450,6 +450,11 @@ int rrc_nr::establish_rrc_bearer(uint16_t rnti, uint16_t pdu_session_id, srsran:
   return SRSRAN_SUCCESS;
 }
 
+int rrc_nr::release_bearers(uint16_t rnti)
+{
+  return SRSRAN_SUCCESS;
+}
+
 int rrc_nr::allocate_lcid(uint16_t rnti)
 {
   return SRSRAN_SUCCESS;

srsenb/test/ngap/ngap_test.cc

@@ -86,6 +86,7 @@ public:
   {
     return SRSRAN_SUCCESS;
   }
+  int  release_bearers(uint16_t rnti) { return SRSRAN_SUCCESS; }
   int  allocate_lcid(uint16_t rnti) { return SRSRAN_SUCCESS; }
   void write_dl_info(uint16_t rnti, srsran::unique_byte_buffer_t sdu) {}
 };

srsue/hdr/stack/upper/nas_5g.h

@@ -132,10 +132,12 @@ private:
   int send_pdu_session_establishment_request(uint32_t                 transaction_identity,
                                              uint16_t                 pdu_session_id,
                                              const pdu_session_cfg_t& pdu_session);
+  int send_deregistration_request_ue_originating();
 
   void fill_security_caps(srsran::nas_5g::ue_security_capability_t& sec_caps);
   int  apply_security_config(srsran::unique_byte_buffer_t& pdu, uint8_t sec_hdr_type);
-
+  int  handle_deregistration_accept_ue_originating(
+       srsran::nas_5g::deregistration_accept_ue_originating_t& deregistration_accept_ue_originating);
   // message handler
   int handle_registration_accept(srsran::nas_5g::registration_accept_t& registration_accept);
   int handle_registration_reject(srsran::nas_5g::registration_reject_t& registration_reject);
@@ -168,6 +170,7 @@ private:
   int  configure_pdu_session(uint16_t pdu_session_id);
   bool unestablished_pdu_sessions();
   int  get_unestablished_pdu_session(uint16_t& pdu_session_id, pdu_session_cfg_t& pdu_session_cfg);
+  int  reset_pdu_sessions();
 
   struct pdu_session_t {
     bool              configured;

srsue/src/stack/upper/nas_5g.cc

@@ -136,6 +136,7 @@ void nas_5g::run_tti()
       break;
     case mm5g_state_t::state_t::deregistered_initiated:
       logger.debug("UE detaching...");
+      send_deregistration_request_ue_originating();
       break;
     default:
       break;
@@ -222,6 +223,9 @@ int nas_5g::write_pdu(srsran::unique_byte_buffer_t pdu)
     case msg_opts::options::dl_nas_transport:
       handle_dl_nas_transport(nas_msg.dl_nas_transport());
       break;
+    case msg_opts::options::deregistration_accept_ue_originating:
+      handle_deregistration_accept_ue_originating(nas_msg.deregistration_accept_ue_originating());
+      break;
     default:
       logger.error(
           "Not handling NAS message type: %s (0x%02x)", nas_msg.hdr.message_type.to_string(), nas_msg.hdr.message_type);
@@ -587,6 +591,51 @@ int nas_5g::send_pdu_session_establishment_request(uint32_t                 tran
   return SRSRAN_SUCCESS;
 }
 
+int nas_5g::send_deregistration_request_ue_originating()
+{
+  unique_byte_buffer_t pdu = srsran::make_byte_buffer();
+  if (!pdu) {
+    logger.error("Couldn't allocate PDU in %s().", __FUNCTION__);
+    return SRSRAN_ERROR;
+  }
+
+  logger.info("Generating Deregistration Request (UE Originating)");
+
+  nas_5gs_msg                              nas_msg;
+  deregistration_request_ue_originating_t& deregistration_request = nas_msg.set_deregistration_request_ue_originating();
+
+  // Note 5.5.2.2.2 : AMF does not send a Deregistration Accept NAS message if De-registration type IE indicates "switch
+  // off"
+  deregistration_request.de_registration_type.switch_off.value =
+      de_registration_type_t::switch_off_type_::options::normal_de_registration;
+
+  mobile_identity_5gs_t::suci_s& suci = deregistration_request.mobile_identity_5gs.set_suci();
+  suci.supi_format                    = mobile_identity_5gs_t::suci_s::supi_format_type_::options::imsi;
+  usim->get_home_mcc_bytes(suci.mcc.data(), suci.mcc.size());
+  usim->get_home_mnc_bytes(suci.mnc.data(), suci.mnc.size());
+
+  deregistration_request.ng_ksi.nas_key_set_identifier.value =
+      key_set_identifier_t::nas_key_set_identifier_type_::options::no_key_is_available_or_reserved;
+
+  if (nas_msg.pack(pdu) != SRSASN_SUCCESS) {
+    logger.error("Failed to pack Deregistration Request (UE Originating).");
+    return SRSRAN_ERROR;
+  }
+
+  if (pcap != nullptr) {
+    pcap->write_nas(pdu.get()->msg, pdu.get()->N_bytes);
+  }
+
+  logger.info("Sending Deregistration Request (UE Originating)");
+  rrc_nr->write_sdu(std::move(pdu));
+
+  reset_pdu_sessions();
+
+  // TODO: Delete / Reset context (ctxt & ctxt_5g)
+
+  return SRSASN_SUCCESS;
+}
+
 // Message handler
 int nas_5g::handle_registration_accept(registration_accept_t& registration_accept)
 {
@@ -797,6 +846,13 @@ int nas_5g::handle_n1_sm_information(std::vector<uint8_t> payload_container_cont
   return SRSRAN_SUCCESS;
 }
 
+int nas_5g::handle_deregistration_accept_ue_originating(
+    srsran::nas_5g::deregistration_accept_ue_originating_t& deregistration_accept_ue_originating)
+{
+  logger.info("Received Deregistration Request (UE Originating)");
+  return SRSASN_SUCCESS;
+}
+
 /*******************************************************************************
  * NAS Timers
  ******************************************************************************/
@@ -823,7 +879,7 @@ int nas_5g::switch_on()
 int nas_5g::switch_off()
 {
   logger.info("Switching off");
-  // TODO
+  state.set_deregistered_initiated();
   return SRSRAN_SUCCESS;
 }
 
@@ -847,6 +903,16 @@ int nas_5g::start_service_request()
   return SRSRAN_SUCCESS;
 }
 
+int nas_5g::reset_pdu_sessions()
+{
+  for (auto pdu_session : pdu_sessions) {
+    pdu_session.established    = false;
+    pdu_session.pdu_session_id = 0;
+  }
+
+  return SRSRAN_SUCCESS;
+}
+
 /*******************************************************************************
  * Helpers
  ******************************************************************************/