Starting to change SPGW to handle release access bearers request. Changing MME GTPC entity to contain an IMSI to sgw_ctr_fteid and ctr_teid to IMSI maps.

srsepc/hdr/mme/mme_gtpc.h

@@ -68,7 +68,8 @@ private:
   in_addr_t m_mme_gtpc_ip;
 
   uint32_t m_next_ctrl_teid;
-  std::map<uint32_t,uint32_t> m_teid_to_mme_s1ap_id;
+  std::map<uint32_t,uint64_t> m_ctr_teid_to_imsi;
+  std::map<uint64_t,srslte::gtpc_f_teid_ie> m_imsi_to_ctr_fteid;
 
 };
 

srsepc/hdr/mme/s1ap_common.h

@@ -127,7 +127,6 @@ typedef struct{
     enum erab_state state;
     uint8_t erab_id;
     srslte::gtpc_f_teid_ie enb_fteid;
-    srslte::gtpc_f_teid_ie sgw_ctrl_fteid;
     srslte::gtpc_f_teid_ie sgw_s1u_fteid;
     srslte::gtpc_pdn_address_allocation_ie pdn_addr_alloc;
 } erab_ctx_t;
@@ -148,8 +147,9 @@ typedef struct{
   uint32_t mme_ue_s1ap_id;
   struct   sctp_sndrcvinfo enb_sri;
   ecm_state_t ecm_state; 
-  bool eit;
+  srslte::gtpc_f_teid_ie sgw_ctrl_fteid;
   erab_ctx_t erabs_ctx[MAX_ERABS_PER_UE];
+  bool eit;
 } ue_ecm_ctx_t;
 
 

srsepc/src/mme/mme_gtpc.cc

@@ -298,4 +298,31 @@ mme_gtpc::send_delete_session_request(ue_ecm_ctx_t *ue_ecm_ctx)
   //TODO Handle delete session response
   return;
 }
+
+void
+mme_gtpc::send_release_access_bearers_request(ue_ecm_ctx_t *ecm_ctx) 
+{
+  m_mme_gtpc_log->info("Sending GTP-C Delete Access Bearers Request\n");
+  srslte::gtpc_pdu rel_req_pdu;
+  if(ecm_ctx->state != ECM_ )
+  {
+
+  }
+  srslte::gtpc_f_teid_ie *sgw_ctrl_fteid = NULL;
+
+  srslte::gtpc_header *header = &rel_req_pdu.header;
+  header->teid_present = true;
+  header->teid = sgw_ctrl_fteid->teid;
+  header->type = srslte::GTPC_MSG_TYPE_RELEASE_ACCESS_BEARERS_REQUEST;
+
+  srslte::gtpc_release_access_bearers_request *rel_req = &rel_req_pdu.choice.release_access_bearers_request;
+  del_req->cause.cause_value = srslte::GTPC_CAUSE_VALUE_ISR_DEACTIVATION;
+  m_mme_gtpc_log->info("GTP-C Release Access Berarers Request -- S-GW Control TEID %d\n", sgw_ctrl_fteid->teid );
+
+  srslte::gtpc_pdu del_resp_pdu;
+  m_spgw->handle_delete_session_request(&del_req_pdu, &del_resp_pdu);
+
+  //TODO Handle delete session response
+  return;
+}
 } //namespace srsepc

srsepc/src/mme/s1ap_nas_transport.cc

@@ -707,7 +707,7 @@ s1ap_nas_transport::handle_nas_service_request(uint32_t m_tmsi,
       m_s1ap_log->info("Generating KeNB with UL NAS COUNT: %d\n",ue_emm_ctx->security_ctxt.ul_nas_count);
       //FIXME Send Modify context request OR send ctx release command and wait for the reply.
       m_mme_gtpc->send_create_session_request(ue_ecm_ctx.imsi, ue_ecm_ctx.mme_ue_s1ap_id,false);
-      m_s1ap_log->console("UE ESM Ctr TEID %d\n", ue_ecm_ctx.erabs_ctx[5].sgw_ctrl_fteid.teid);
+      m_s1ap_log->console("UE ESM Ctr TEID %d\n", ue_ecm_ctx.sgw_ctrl_fteid.teid);
       // m_s1ap->m_s1ap_ctx_mngmt_proc->send_initial_context_setup_request(ue_);
     }
   }