Merge pull request #247 from softwareradiosystems/detach

add detach support (for switch off)

lib/include/srslte/interfaces/ue_interfaces.h

@@ -146,7 +146,7 @@ class nas_interface_ue
 {
 public:
   virtual bool attach_request() = 0;
-  virtual bool deattach_request() = 0;
+  virtual bool detach_request() = 0;
 };
 
 // NAS interface for UE

srsue/hdr/ue.h

@@ -69,8 +69,8 @@ public:
 
   bool init(all_args_t *args_);
   void stop();
-  bool attach();
-  bool deattach();
+  bool switch_on();
+  bool switch_off();
   bool is_attached();
   void start_plot();
   void print_mbms();

srsue/hdr/ue_base.h

@@ -159,8 +159,8 @@ public:
 
   virtual bool init(all_args_t *args_) = 0;
   virtual void stop() = 0;
-  virtual bool attach() = 0;
-  virtual bool deattach() = 0;
+  virtual bool switch_on() = 0;
+  virtual bool switch_off() = 0;
   virtual bool is_attached() = 0;
   virtual void start_plot() = 0;
 

srsue/hdr/upper/nas.h

@@ -90,7 +90,7 @@ public:
 
   // UE interface
   bool attach_request();
-  bool deattach_request();
+  bool detach_request();
 
   // PCAP
   void start_pcap(srslte::nas_pcap *pcap_);
@@ -186,6 +186,7 @@ private:
   void send_authentication_failure(const uint8_t cause, const uint8_t* auth_fail_param);
   void gen_pdn_connectivity_request(LIBLTE_BYTE_MSG_STRUCT *msg);
   void send_security_mode_reject(uint8_t cause);
+  void send_detach_request(bool switch_off);
 
   // security context persistence file
   bool read_ctxt_file(nas_sec_ctxt *ctxt);

srsue/src/main.cc

@@ -545,7 +545,7 @@ int main(int argc, char *argv[])
   pthread_create(&input, NULL, &input_loop, &args);
 
   printf("Attaching UE...\n");
-  while (!ue->attach() && running) {
+  while (!ue->switch_on() && running) {
     sleep(1);
   }
   if (running) {
@@ -585,6 +585,7 @@ int main(int argc, char *argv[])
     }
     sleep(1);
   }
+  ue->switch_off();
   pthread_cancel(input);
   metricshub.stop();
   ue->stop();

srsue/src/ue.cc

@@ -301,12 +301,27 @@ void ue::stop()
   }
 }
 
-bool ue::attach() {
+bool ue::switch_on() {
   return nas.attach_request();
 }
 
-bool ue::deattach() {
-  return nas.deattach_request();
+bool ue::switch_off() {
+  // generate detach request
+  nas.detach_request();
+
+  // wait for max. 5s for it to be sent (according to TS 24.301 Sec 25.5.2.2)
+  const uint32_t RB_ID_SRB1 = 1;
+  int cnt = 0, timeout = 5;
+  while (rlc.get_buffer_state(RB_ID_SRB1) && ++cnt <= timeout) {
+    sleep(1);
+  }
+  bool detach_sent = true;
+  if (rlc.get_buffer_state(RB_ID_SRB1)) {
+    nas_log.warning("Detach couldn't be sent after %ds.\n", timeout);
+    detach_sent = false;
+  }
+
+  return detach_sent;
 }
 
 bool ue::is_attached()

srsue/src/upper/nas.cc

@@ -172,9 +172,25 @@ bool nas::attach_request() {
   return false;
 }
 
-bool nas::deattach_request() {
-  state = EMM_STATE_DEREGISTERED_INITIATED;
-  nas_log->info("Dettach request not supported\n");
+bool nas::detach_request() {
+  // attempt detach for 5s
+  nas_log->info("Detach Request\n");
+
+  switch (state) {
+    case EMM_STATE_DEREGISTERED:
+      // do nothing ..
+      break;
+    case EMM_STATE_REGISTERED:
+      // send detach request
+      send_detach_request(true);
+      state = EMM_STATE_DEREGISTERED_INITIATED;
+      break;
+    case EMM_STATE_DEREGISTERED_INITIATED:
+      // do nothing ..
+      break;
+    default:
+      break;
+  }
   return false;
 }
 
@@ -1132,6 +1148,63 @@ void nas::send_security_mode_reject(uint8_t cause) {
   rrc->write_sdu(cfg.lcid, msg);
 }
 
+void nas::send_detach_request(bool switch_off)
+{
+  byte_buffer_t *pdu = pool_allocate_blocking;
+  if (!pdu) {
+    nas_log->error("Fatal Error: Couldn't allocate PDU in %s().\n", __FUNCTION__);
+    return;
+  }
+
+  LIBLTE_MME_DETACH_REQUEST_MSG_STRUCT detach_request = {};
+  if (switch_off) {
+    detach_request.detach_type.switch_off = 1;
+    detach_request.detach_type.type_of_detach = LIBLTE_MME_SO_FLAG_SWITCH_OFF;
+  } else {
+    detach_request.detach_type.switch_off = 0;
+    detach_request.detach_type.type_of_detach = LIBLTE_MME_SO_FLAG_NORMAL_DETACH;
+  }
+
+  // GUTI or IMSI detach
+  if (have_guti && have_ctxt) {
+    detach_request.eps_mobile_id.type_of_id = LIBLTE_MME_EPS_MOBILE_ID_TYPE_GUTI;
+    memcpy(&detach_request.eps_mobile_id.guti, &ctxt.guti, sizeof(LIBLTE_MME_EPS_MOBILE_ID_GUTI_STRUCT));
+    detach_request.nas_ksi.tsc_flag      = LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE;
+    detach_request.nas_ksi.nas_ksi       = ctxt.ksi;
+    nas_log->info("Requesting Detach with GUTI\n");
+    liblte_mme_pack_detach_request_msg(&detach_request,
+                                       LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY,
+                                       ctxt.tx_count,
+                                       (LIBLTE_BYTE_MSG_STRUCT *) pdu);
+
+    // Add MAC
+    if (pdu->N_bytes > 5) {
+      integrity_generate(&k_nas_int[16],
+                         ctxt.tx_count,
+                         SECURITY_DIRECTION_UPLINK,
+                         &pdu->msg[5],
+                         pdu->N_bytes - 5,
+                         &pdu->msg[1]);
+    } else {
+      nas_log->error("Invalid PDU size %d\n", pdu->N_bytes);
+    }
+  } else {
+    detach_request.eps_mobile_id.type_of_id = LIBLTE_MME_EPS_MOBILE_ID_TYPE_IMSI;
+    detach_request.nas_ksi.tsc_flag      = LIBLTE_MME_TYPE_OF_SECURITY_CONTEXT_FLAG_NATIVE;
+    detach_request.nas_ksi.nas_ksi       = 0;
+    usim->get_imsi_vec(detach_request.eps_mobile_id.imsi, 15);
+    nas_log->info("Requesting IMSI detach (IMSI=%s)\n", usim->get_imsi_str().c_str());
+    liblte_mme_pack_detach_request_msg(&detach_request, LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT *) pdu);
+  }
+
+  if(pcap != NULL) {
+    pcap->write_nas(pdu->msg, pdu->N_bytes);
+  }
+
+  nas_log->info("Sending detach request\n");
+  rrc->write_sdu(cfg.lcid, pdu);
+}
+
 
 void nas::send_authentication_response(const uint8_t* res, const size_t res_len, const uint8_t sec_hdr_type) {
   byte_buffer_t *pdu = pool_allocate_blocking;