Adding delete session request.

lib/include/srslte/asn1/gtpc.h

@@ -76,6 +76,8 @@ typedef union gtpc_msg_choice
   struct gtpc_create_session_response create_session_response;
   struct gtpc_modify_bearer_request modify_bearer_request;
   struct gtpc_modify_bearer_response modify_bearer_response;
+  struct gtpc_delete_session_request delete_session_request;
+  struct gtpc_delete_session_response delete_session_response;
 } gtpc_msg_choice_t;
 
 /****************************************************************************

lib/include/srslte/asn1/gtpc_msg.h

@@ -377,5 +377,38 @@ struct gtpc_modify_bearer_response
   //ext
 };
 
+/****************************************************************************
+ *
+ * GTP-C v2 Delete Session Resquest
+ * Ref: 3GPP TS 29.274 v10.14.0 Table 7.2.9.1-1
+ *
+ ***************************************************************************/
+
+struct gtpc_delete_session_request
+{
+  struct gtpc_cause_ie cause;
+  //Linked EPS Bearer ID
+  //User Location Information
+  //Indication Flags
+  //Protocol Configuration Options
+  //Originating Node
+  //Private extension
+};
+
+/****************************************************************************
+  *
+  * GTP-C v2 Delete Session Response
+  * Ref: 3GPP TS 29.274 v10.14.0 Table 7.2.10.1-1
+  *
+  ***************************************************************************/
+
+struct gtpc_delete_session_response
+{
+  struct gtpc_cause_ie cause;
+  //Recovery
+  //Protocol Configuration Options
+  //Private extension
+};
+
 } //namespace
 #endif //GTPC_V2_MSG_H

srsepc/hdr/mme/mme_gtpc.h

@@ -52,6 +52,7 @@ public:
   void handle_create_session_response(srslte::gtpc_pdu *cs_resp_pdu);
   void send_modify_bearer_request(erab_ctx_t *bearer_ctx);
   void handle_modify_bearer_response(srslte::gtpc_pdu *mb_resp_pdu);
+  void send_delete_session_request(ue_ctx_t *ue_ctx);
 
 private:
 

srsepc/hdr/spgw/spgw.h

@@ -75,6 +75,7 @@ public:
 
   void handle_create_session_request(struct srslte::gtpc_create_session_request *cs_req, struct srslte::gtpc_pdu *cs_resp_pdu);
   void handle_modify_bearer_request(struct srslte::gtpc_pdu *mb_req_pdu, struct srslte::gtpc_pdu *mb_resp_pdu);
+  void handle_delete_session_request(struct srslte::gtpc_pdu *del_req_pdu, struct srslte::gtpc_pdu *del_resp_pdu);
 
   void handle_sgi_pdu(srslte::byte_buffer_t *msg);
   void handle_s1u_pdu(srslte::byte_buffer_t *msg);

srsepc/src/mme/mme_gtpc.cc

@@ -212,4 +212,38 @@ mme_gtpc::handle_modify_bearer_response(srslte::gtpc_pdu *mb_resp_pdu)
   return;
 }
 
+void
+mme_gtpc::send_delete_session_request(ue_ctx_t *ue_ctx) 
+{
+  m_mme_gtpc_log->info("Sending GTP-C Delete Session Request request\n");
+  srslte::gtpc_pdu del_req_pdu;
+  srslte::gtpc_f_teid_ie *sgw_ctrl_fteid;
+
+  //FIXME the UE control TEID sould be stored in the UE ctxt, not in the E-RAB ctxt
+  //Maybe a mme_s1ap_id to ctrl teid map as well?
+
+  for(int i = 0; i<MAX_ERABS_PER_UE; i++)
+  {
+    if(ue_ctx->erabs_ctx[i].state != ERAB_DEACTIVATED)
+    {
+      sgw_ctrl_fteid = &ue_ctx->erabs_ctx[i].sgw_ctrl_fteid;
+      break;
+    }
+  }
+
+  srslte::gtpc_header *header = &del_req_pdu.header;
+  header->teid_present = true;
+  header->teid = sgw_ctrl_fteid->teid;
+  header->type = srslte::GTPC_MSG_TYPE_DELETE_SESSION_REQUEST;
+
+  srslte::gtpc_delete_session_request *del_req = &del_req_pdu.choice.delete_session_request;
+  del_req->cause.cause_value = srslte::GTPC_CAUSE_VALUE_ISR_DEACTIVATION;
+  m_mme_gtpc_log->info("GTP-C Delete Session 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.cc

@@ -506,7 +506,7 @@ s1ap::handle_ue_context_release_request(LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASEREQU
   {
     m_s1ap_log->error("Could not find eNB for this request.\n");
     return false;
-  }  
+  } 
   uint16_t enb_id = it->second; 
   std::map<uint16_t,std::set<uint32_t> >::iterator ue_set = m_enb_id_to_ue_ids.find(enb_id);
   if(ue_set == m_enb_id_to_ue_ids.end())
@@ -517,7 +517,20 @@ s1ap::handle_ue_context_release_request(LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASEREQU
   ue_set->second.erase(mme_ue_s1ap_id);
 
   //Delete any context at the SPGW
-  //m_spgw->delete_session_request(ue_ctx->imsi);
+  bool active = false;
+  for(int i=0;i<MAX_ERABS_PER_UE;i++)
+  {
+    if(ue_ctx->second->erabs_ctx[i].state != ERAB_DEACTIVATED)
+    {
+      active = true;
+      break;
+    }
+  }
+  if(active == true)
+  {
+    //There are active E-RABs, send delete session request
+    m_mme_gtpc->send_delete_session_request(ue_ctx->second);
+  }
 
   //Delete UE context
   delete ue_ctx->second;

srsepc/src/spgw/spgw.cc

@@ -375,7 +375,7 @@ spgw::handle_sgi_pdu(srslte::byte_buffer_t *msg)
   int n = sendto(m_s1u,msg->msg,msg->N_bytes,0,(struct sockaddr*) &enb_addr,sizeof(enb_addr));
   if(n<0)
   {
-    m_spgw_log->console("Error sending packet to eNB\n");
+    m_spgw_log->error("Error sending packet to eNB\n");
     return;
   }
   //m_spgw_log->console("Sent packet to %s:%d. Bytes=%d\n",inet_ntoa(enb_addr.sin_addr), GTPU_RX_PORT,n);
@@ -437,7 +437,8 @@ spgw::handle_create_session_request(struct srslte::gtpc_create_session_request *
   in_addr_t ue_ip = get_new_ue_ipv4();
 
   uint8_t default_bearer_id = 5;
-  //Save the UE IP to User TEID map //TODO!!!
+
+  //Save the UE IP to User TEID map 
   spgw_tunnel_ctx_t *tunnel_ctx = new spgw_tunnel_ctx_t;
   tunnel_ctx->imsi = cs_req->imsi;
   tunnel_ctx->ebi = default_bearer_id;
@@ -449,6 +450,7 @@ spgw::handle_create_session_request(struct srslte::gtpc_create_session_request *
   tunnel_ctx->up_ctrl_fteid.teid = spgw_uplink_ctrl_teid;
   tunnel_ctx->ue_ipv4 = ue_ip;
   m_teid_to_tunnel_ctx.insert(std::pair<uint32_t,spgw_tunnel_ctx_t*>(spgw_uplink_ctrl_teid,tunnel_ctx));
+
   //Create session response message
   //Setup GTP-C header
   header->piggyback = false;
@@ -479,13 +481,9 @@ spgw::handle_create_session_request(struct srslte::gtpc_create_session_request *
   return;
 }
 
-  /*
-void
-spgw::delete_session_request(uint64_t imsi)
-{
 
-}
+
-  */
+
 void
 spgw::handle_modify_bearer_request(struct srslte::gtpc_pdu *mb_req_pdu, struct srslte::gtpc_pdu *mb_resp_pdu)
 {
@@ -541,4 +539,32 @@ spgw::handle_modify_bearer_request(struct srslte::gtpc_pdu *mb_req_pdu, struct s
   printf("%d %d\n",mb_resp->eps_bearer_context_modified.ebi, tunnel_ctx->ebi);
   mb_resp->eps_bearer_context_modified.cause.cause_value = srslte::GTPC_CAUSE_VALUE_REQUEST_ACCEPTED;
 }
+
+void
+spgw::handle_delete_session_request(struct srslte::gtpc_pdu *del_req_pdu, struct srslte::gtpc_pdu *del_resp_pdu)
+{
+  //Find tunel ctxt
+  uint32_t ctrl_teid = del_req_pdu->header.teid;
+  std::map<uint32_t,spgw_tunnel_ctx_t*>::iterator tunnel_it = m_teid_to_tunnel_ctx.find(ctrl_teid);
+  if(tunnel_it == m_teid_to_tunnel_ctx.end())
+  {
+    m_spgw_log->warning("Could not find TEID %d to delete\n",ctrl_teid);
+    return;
+  }
+  spgw_tunnel_ctx_t *tunnel_ctx = tunnel_it->second;
+  in_addr_t ue_ipv4 = tunnel_ctx->ue_ipv4;
+
+  //Delete data tunnel
+  pthread_mutex_lock(&m_mutex);
+  std::map<in_addr_t,srslte::gtpc_f_teid_ie>::iterator data_it = m_ip_to_teid.find(tunnel_ctx->ue_ipv4);
+  if(data_it != m_ip_to_teid.end())
+  {
+    m_ip_to_teid.erase(data_it);
+  }
+  pthread_mutex_unlock(&m_mutex);
+
+  delete tunnel_ctx; 
+  return;
+}
+
 } //namespace srsepc