ue,stack: clear all EPS bearers when going RRC idle

the EPS bearer manager was only informed when a single DRB
was removed but not when entering idle which requires to
remove all bearers.

This cause the service request to fail.

lib/include/srsran/interfaces/ue_interfaces.h

@@ -31,6 +31,7 @@ public:
   virtual srsran::tti_point get_current_tti()                                                              = 0;
   virtual void              add_eps_bearer(uint8_t eps_bearer_id, srsran::srsran_rat_t rat, uint32_t lcid) = 0;
   virtual void              remove_eps_bearer(uint8_t eps_bearer_id)                                       = 0;
+  virtual void              reset_eps_bearers()                                                            = 0;
 };
 
 // Combined interface for PHY to access stack (MAC and RRC)

srsue/hdr/stack/bearer_manager.h

@@ -45,9 +45,12 @@ public:
   /// Registers EPS bearer with PDCP RAT type and LCID
   void add_eps_bearer(uint8_t eps_bearer_id, srsran::srsran_rat_t rat, uint32_t lcid);
 
-  /// EPS bearer is removed from map when the associated DRB is deleted (e.g. after connection release)
+  /// Single EPS bearer is removed from map when the associated DRB is deleted
   void remove_eps_bearer(uint8_t eps_bearer_id);
 
+  /// All registered bearer are removed (e.g. after connection release)
+  void reset();
+
   // GW interface
   bool has_active_radio_bearer(uint32_t eps_bearer_id);
 

srsue/hdr/stack/ue_stack_lte.h

@@ -167,6 +167,7 @@ public:
   tti_point get_current_tti() final { return current_tti; }
   void      add_eps_bearer(uint8_t eps_bearer_id, srsran::srsran_rat_t rat, uint32_t lcid) final;
   void      remove_eps_bearer(uint8_t eps_bearer_id) final;
+  void      reset_eps_bearers() final;
 
   srsran::ext_task_sched_handle get_task_sched() { return {&task_sched}; }
 

srsue/hdr/stack/ue_stack_nr.h

@@ -106,9 +106,10 @@ public:
   bool has_active_radio_bearer(uint32_t eps_bearer_id) final { return true; /* TODO: add EPS to LCID mapping */ }
 
   // Interface for RRC
-  srsran::tti_point get_current_tti() { return srsran::tti_point{0}; };
-  void              add_eps_bearer(uint8_t eps_bearer_id, srsran::srsran_rat_t rat, uint32_t lcid) final{};
-  void              remove_eps_bearer(uint8_t eps_bearer_id) final{};
+  srsran::tti_point get_current_tti() { return srsran::tti_point{0}; }
+  void              add_eps_bearer(uint8_t eps_bearer_id, srsran::srsran_rat_t rat, uint32_t lcid) final {}
+  void              remove_eps_bearer(uint8_t eps_bearer_id) final {}
+  void              reset_eps_bearers() final {}
 
 private:
   void run_thread() final;

srsue/src/stack/bearer_manager.cc

@@ -36,7 +36,6 @@ void bearer_manager::add_eps_bearer(uint8_t eps_bearer_id, srsran::srsran_rat_t
   logger.info("Registered EPS bearer ID %d for lcid=%d over %s-PDCP", eps_bearer_id, lcid, to_string(rat).c_str());
 }
 
-/// EPS bearer is removed from map when the associated DRB is deleted (e.g. after connection release)
 void bearer_manager::remove_eps_bearer(uint8_t eps_bearer_id)
 {
   srsran::rwlock_write_guard rw_lock(rwlock);
@@ -49,6 +48,13 @@ void bearer_manager::remove_eps_bearer(uint8_t eps_bearer_id)
   logger.info("Removed mapping for EPS bearer ID %d", eps_bearer_id);
 }
 
+void bearer_manager::reset()
+{
+  srsran::rwlock_write_guard rw_lock(rwlock);
+  eps_rb_map.clear();
+  logger.info("Reset EPS bearer manager");
+}
+
 // GW interface
 bool bearer_manager::has_active_radio_bearer(uint32_t eps_bearer_id)
 {

srsue/src/stack/rrc/rrc.cc

@@ -1120,6 +1120,7 @@ void rrc::leave_connected()
   rlc->reset();
   pdcp->reset();
   set_mac_default();
+  stack->reset_eps_bearers();
 
   // 1> indicate the release of the RRC connection to upper layers together with the release cause;
   nas->left_rrc_connected();

srsue/src/stack/ue_stack_lte.cc

@@ -391,6 +391,11 @@ bool ue_stack_lte::has_active_radio_bearer(uint32_t eps_bearer_id)
   return bearers.has_active_radio_bearer(eps_bearer_id);
 }
 
+void ue_stack_lte::reset_eps_bearers()
+{
+  bearers.reset();
+}
+
 /**
  * Check whether nas is attached
  * @return bool wether NAS is in EMM_REGISTERED