Added attach request as a UL info trasnfer in the UE. Added interface to remove eps bearer map when going idle. Fixed bug in GW in assignment of IPv4 addresses. UE seems to rebound from the service reject now.

lib/include/srslte/interfaces/ue_interfaces.h

@@ -129,6 +129,7 @@ public:
     BARRING_MT,
     BARRING_ALL
   } barring_t;
+  virtual void     leave_connected()                                          = 0;
   virtual void     set_barring(barring_t barring)                             = 0;
   virtual void     paging(asn1::rrc::s_tmsi_s* ue_identiy)                    = 0;
   virtual bool     is_attached()                                              = 0;

srsue/hdr/stack/upper/nas.h

@@ -54,6 +54,7 @@ public:
   emm_state_t get_state();
 
   // RRC interface
+  void     leave_connected();
   void     paging(asn1::rrc::s_tmsi_s* ue_identiy);
   void     set_barring(barring_t barring);
   void     write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu);

srsue/src/stack/rrc/rrc.cc

@@ -1730,6 +1730,7 @@ void rrc::leave_connected()
   drb_up = false;
   security_is_activated = false;
   measurements.reset();
+  nas->leave_connected();
   pdcp->reset();
   rlc->reset();
   phy->reset();

srsue/src/stack/upper/nas.cc

@@ -232,6 +232,10 @@ bool nas::detach_request() {
   return false;
 }
 
+void nas::leave_connected() {
+  eps_bearer.clear();
+  return;
+}
 
 bool nas::is_attached() {
   return state == EMM_STATE_REGISTERED;
@@ -702,6 +706,7 @@ void nas::parse_attach_accept(uint32_t lcid, unique_byte_buffer_t pdu)
       nas_log->warning("EMM Cause: %d\n", attach_accept.emm_cause );
     }
     if (LIBLTE_MME_PDN_TYPE_IPV4 == act_def_eps_bearer_context_req.pdn_addr.pdn_type) {
+      ip_addr = 0;
       ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[0] << 24;
       ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[1] << 16;
       ip_addr |= act_def_eps_bearer_context_req.pdn_addr.addr[2] << 8;
@@ -1077,7 +1082,7 @@ void nas::parse_service_reject(uint32_t lcid, unique_byte_buffer_t pdu)
   LIBLTE_MME_SERVICE_REJECT_MSG_STRUCT service_reject;
   if (liblte_mme_unpack_service_reject_msg((LIBLTE_BYTE_MSG_STRUCT*)pdu.get(), &service_reject)) {
     nas_log->error("Error unpacking service reject.\n");
-    goto exit;
+    return;
   }
 
   nas_log->console("Received service reject with EMM cause=0x%x.\n", service_reject.emm_cause);
@@ -1088,8 +1093,18 @@ void nas::parse_service_reject(uint32_t lcid, unique_byte_buffer_t pdu)
 
   // FIXME: handle NAS backoff-timers correctly
 
-exit:
+  // Mark state as EMM-DEREGISTERED
-  ctxt.rx_count++;
+  state = EMM_STATE_DEREGISTERED;
+
+  // Reset security context
+  ctxt      = {};
+  have_ctxt = false;
+  have_guti = false;
+
+  // Send attach request after receiving service reject 
+  pdu->clear(); 
+  gen_attach_request(pdu.get());
+  rrc->write_sdu(std::move(pdu));
 }
 
 void nas::parse_esm_information_request(uint32_t lcid, unique_byte_buffer_t pdu)