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

@@ -129,14 +129,15 @@ public:
     BARRING_MT,
     BARRING_ALL
   } barring_t;
-  virtual void      set_barring(barring_t barring) = 0;
-  virtual void      paging(asn1::rrc::s_tmsi_s* ue_identiy)              = 0;
-  virtual bool      is_attached() = 0;
-  virtual void      write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu) = 0;
-  virtual uint32_t  get_k_enb_count() = 0;
-  virtual bool      get_k_asme(uint8_t *k_asme_, uint32_t n) = 0;
-  virtual uint32_t  get_ipv4_addr() = 0;
-  virtual bool      get_ipv6_addr(uint8_t *ipv6_addr) = 0;
+  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;
+  virtual void     write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu) = 0;
+  virtual uint32_t get_k_enb_count()                                          = 0;
+  virtual bool     get_k_asme(uint8_t* k_asme_, uint32_t n)                   = 0;
+  virtual uint32_t get_ipv4_addr()                                            = 0;
+  virtual bool     get_ipv6_addr(uint8_t* ipv6_addr)                          = 0;
 };
 
 // NAS interface for UE

srsue/hdr/stack/upper/nas.h

@@ -54,14 +54,15 @@ 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     set_barring(barring_t barring);
   void     write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
   uint32_t get_k_enb_count();
-  bool is_attached();
-  bool get_k_asme(uint8_t *k_asme_, uint32_t n);
+  bool     is_attached();
+  bool     get_k_asme(uint8_t* k_asme_, uint32_t n);
   uint32_t get_ipv4_addr();
-  bool get_ipv6_addr(uint8_t *ipv6_addr);
+  bool     get_ipv6_addr(uint8_t* ipv6_addr);
 
   // UE interface
   bool attach_request();

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/gw.cc

@@ -390,8 +390,8 @@ int gw::init_if(char* err_str)
 
   // Delete link-local IPv6 address.
   struct in6_addr in6p;
-  char addr_str[INET6_ADDRSTRLEN];
-  if(find_ipv6_addr(&in6p)){
+  char            addr_str[INET6_ADDRSTRLEN];
+  if (find_ipv6_addr(&in6p)) {
     log.debug("Found link-local IPv6 address: %s\n", inet_ntop(AF_INET6, &in6p, addr_str, INET6_ADDRSTRLEN));
     del_ipv6_addr(&in6p);
   } else {

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:
-  ctxt.rx_count++;
+  // Mark state as EMM-DEREGISTERED
+  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)