Starting to save UE context.

srsepc/hdr/mme/s1ap.h

@@ -76,18 +76,20 @@ public:
 
 private:
 
-  s1ap_args_t                  m_s1ap_args;
+  s1ap_args_t                    m_s1ap_args;
-  uint32_t                     m_plmn;
+  uint32_t                       m_plmn;
-  srslte::byte_buffer_pool    *m_pool;
+  srslte::byte_buffer_pool      *m_pool;
-  srslte::log                 *m_s1ap_log;
+  srslte::log                   *m_s1ap_log;
 
   hss *m_hss;
   int m_s1mme;
-  std::map<uint16_t,enb_ctx_t*> m_active_enbs;
+  std::map<uint16_t, enb_ctx_t*> m_active_enbs;
-  uint32_t m_next_mme_ue_s1ap_id;
+  std::map<uint32_t, ue_ctx_t*>  m_active_ues;
+
+  uint32_t                       m_next_mme_ue_s1ap_id;
  
-  s1ap_mngmt_proc m_s1ap_mngmt_proc;
+  s1ap_mngmt_proc                m_s1ap_mngmt_proc;
-  s1ap_nas_transport m_s1ap_nas_transport;
+  s1ap_nas_transport             m_s1ap_nas_transport;
 };
 
 

srsepc/hdr/mme/s1ap_common.h

@@ -48,4 +48,11 @@ typedef struct{
   struct   sctp_sndrcvinfo sri;
 } enb_ctx_t;
 
+typedef struct{
+  uint64_t imsi;
+  uint32_t enb_ue_s1ap_id;
+  uint32_t mme_ue_s1ap_id;
+  uint8_t  xres[16];
+} ue_ctx_t;
+
 #endif

srsepc/hdr/mme/s1ap_nas_transport.h

@@ -41,6 +41,7 @@ public:
   void set_log(srslte::log *s1ap_logger);
   bool unpack_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSAGE_STRUCT *init_ue, LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT *attach_req, LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT *pdn_con_req);
   bool pack_authentication_request(srslte::byte_buffer_t *reply_msg, uint32_t enb_ue_s1ap_id, uint32_t next_mme_ue_s1ap_id, uint8_t *autn,uint8_t *rand);
+  bool unpack_authentication_response(LIBLTE_S1AP_MESSAGE_UPLINKNASTRANSPORT_STRUCT *ul_xport, LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT *auth_resp);
 
   void log_unhandled_attach_request_ies(const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT *attach_req);
   void log_unhandled_pdn_con_request_ies(const LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT *pdn_con_req);

srsepc/src/mme/s1ap.cc

@@ -250,10 +250,12 @@ s1ap::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSAGE_STRUCT *ini
   uint8_t     rand[6];
   uint8_t     xres[16];
 
+  ue_ctx_t ue_ctx;
+
  /*Get info from initial UE message*/ 
-  uint32_t enb_ue_s1ap_id = init_ue->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID;
+  ue_ctx.enb_ue_s1ap_id = init_ue->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID;
-  m_s1ap_log->console("Received Initial UE Message. eNB-UE S1AP Id: %d\n",enb_ue_s1ap_id);
+  m_s1ap_log->console("Received Initial UE Message. eNB-UE S1AP Id: %d\n", ue_ctx.enb_ue_s1ap_id);
-  m_s1ap_log->info("Received Initial UE Message. eNB-UE S1AP Id: %d\n",enb_ue_s1ap_id);
+  m_s1ap_log->info("Received Initial UE Message. eNB-UE S1AP Id: %d\n", ue_ctx.enb_ue_s1ap_id);
 
   /*Log unhandled Initial UE message IEs*/
   m_s1ap_nas_transport.log_unhandled_initial_ue_message_ies(init_ue);
@@ -278,17 +280,24 @@ s1ap::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSAGE_STRUCT *ini
   uint8_t proc_transaction_id = pdn_con_req.proc_transaction_id; //TODO: Transaction ID unused
 
   //Get Authentication Vectors from HSS
-  if(!m_hss->gen_auth_info_answer_milenage(imsi, k_asme, autn, rand, xres))
+  if(!m_hss->gen_auth_info_answer_milenage(imsi, k_asme, autn, rand, ue_ctx.xres))
   {
     m_s1ap_log->console("User not found. IMSI %015lu\n",imsi);
     m_s1ap_log->info("User not found. IMSI %015lu\n",imsi);
     return false;
   }
- 
+
+  //Save UE context
+  ue_ctx.imsi = imsi;
+  ue_ctx.mme_ue_s1ap_id = m_next_mme_ue_s1ap_id++; 
+  
+  ue_ctx_t *ue_ptr = new ue_ctx_t;//TODO use buffer pool here?
+  memcpy(ue_ptr,&ue_ctx,sizeof(ue_ctx));
+  m_active_ues.insert(std::pair<uint32_t,ue_ctx_t*>(ue_ptr->mme_ue_s1ap_id,ue_ptr));
  
   //Pack NAS Authentication Request in Downlink NAS Transport msg
   srslte::byte_buffer_t *reply_msg = m_pool->allocate();
-  m_s1ap_nas_transport.pack_authentication_request(reply_msg, enb_ue_s1ap_id, m_next_mme_ue_s1ap_id++, autn, rand);
+  m_s1ap_nas_transport.pack_authentication_request(reply_msg, ue_ctx.enb_ue_s1ap_id, ue_ctx.mme_ue_s1ap_id, autn, rand);
   
   //Send Reply to eNB
   ssize_t n_sent = sctp_send(m_s1mme,reply_msg->msg, reply_msg->N_bytes, enb_sri, 0);
@@ -307,12 +316,36 @@ bool
 s1ap::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRANSPORT_STRUCT *ul_xport, struct sctp_sndrcvinfo *enb_sri)
 {
 
+  bool     ue_valid = true;
   uint32_t enb_ue_s1ap_id = ul_xport->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID;
   uint32_t mme_ue_s1ap_id = ul_xport->MME_UE_S1AP_ID.MME_UE_S1AP_ID;
 
+  LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT auth_resp;
+
   m_s1ap_log->console("Received Uplink NAS Transport message. MME-UE S1AP Id: %d\n",mme_ue_s1ap_id);
   m_s1ap_log->info("Received Uplink NAS Transport message. MME-UE S1AP Id: %d\n",mme_ue_s1ap_id);
 
+  //mme_ue_ctx_t ue_ctx = m_mme_ue_map[mme_ue_s1ap_id];
+  //if(mme_ue_ctx == m_mme_ue_map.end())
+  //{
+  //
+  //}
+
+  //Get NAS authentication response
+  if(!m_s1ap_nas_transport.unpack_authentication_response(ul_xport, &auth_resp))
+  {
+    //TODO set up error reply
+    return false;
+  }
+
+  //for(int i=0; i<16;i++)
+  //{
+  //  if(auth_resp.res[i] != ue_ctx.xres[i])
+  //  {
+  //    ue_valid = false;
+  //  }
+  //}
+
   /*
   typedef struct{
   bool                                                         ext;
@@ -329,6 +362,11 @@ s1ap::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRANSPORT_STRUCT
   bool                                                         LHN_ID_present;
   }LIBLTE_S1AP_MESSAGE_UPLINKNASTRANSPORT_STRUCT;
   */
+  /*
+  typedef struct{
+    uint8 res[16];
+  }LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT;
+  */
 
   //m_s1ap_nas_transport.log_unhandled_uplink_nas_transport_message_ies(ul_xport);
 

srsepc/src/mme/s1ap_nas_transport.cc

@@ -154,6 +154,35 @@ s1ap_nas_transport::pack_authentication_request(srslte::byte_buffer_t *reply_msg
   return true;
 }
 
+bool
+s1ap_nas_transport::unpack_authentication_response(LIBLTE_S1AP_MESSAGE_UPLINKNASTRANSPORT_STRUCT *ul_xport,
+                                              LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT *auth_resp )
+{
+
+  /*Get NAS Authentiation Response Message*/
+  uint8_t pd, msg_type;
+  srslte::byte_buffer_t *nas_msg = m_pool->allocate();
+
+  memcpy(nas_msg->msg, &ul_xport->NAS_PDU.buffer, ul_xport->NAS_PDU.n_octets);
+  nas_msg->N_bytes = ul_xport->NAS_PDU.n_octets;
+  liblte_mme_parse_msg_header((LIBLTE_BYTE_MSG_STRUCT *) nas_msg, &pd, &msg_type);
+
+  if(msg_type!=LIBLTE_MME_MSG_TYPE_AUTHENTICATION_RESPONSE){
+    m_s1ap_log->error("Unhandled NAS message within UL NAS Transport message\n");
+    return false;
+  }
+
+  LIBLTE_ERROR_ENUM err = liblte_mme_unpack_authentication_response_msg((LIBLTE_BYTE_MSG_STRUCT *) nas_msg, auth_resp);
+  if(err != LIBLTE_SUCCESS){
+    m_s1ap_log->error("Error unpacking NAS authentication response. Error: %s\n", liblte_error_text[err]);
+    return false;
+  }
+
+  m_pool->deallocate(nas_msg);
+  return true;
+}
+
+
 /*Helper functions*/
 void
 s1ap_nas_transport::log_unhandled_attach_request_ies(const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT *attach_req)
@@ -279,4 +308,7 @@ s1ap_nas_transport::log_unhandled_initial_ue_message_ies(LIBLTE_S1AP_MESSAGE_INI
   return;
 }
 
+
+
+
 } //namespace srsepc