Merge branch 'fix_ngap_shutdown_issue' into 'develop'

Fix issue with SCTP shutdown (no UEs)

See merge request oai/cn5g/oai-cn5g-amf!19

src/amf-app/amf_n2.cpp

@@ -417,21 +417,26 @@ void amf_n2::handle_itti_message(itti_ng_shutdown& itti_msg) {
   gc.get()->ng_state = NGAP_SHUTDOWN;
 
   // Release all the resources related to this interface
+  uint32_t ran_ue_ngap_id = 0;
   for (auto ue_context : ranid2uecontext) {
     if (ue_context.second->gnb_assoc_id == itti_msg.assoc_id) {
-      uint32_t ran_ue_ngap_id = ue_context.second->ran_ue_ngap_id;
+      ran_ue_ngap_id      = ue_context.second->ran_ue_ngap_id;
       long amf_ue_ngap_id = ue_context.second->amf_ue_ngap_id;
       // get NAS context
       std::shared_ptr<nas_context> nc;
-      if (amf_n1_inst->is_amf_ue_id_2_nas_context(amf_ue_ngap_id))
+      if (amf_n1_inst->is_amf_ue_id_2_nas_context(amf_ue_ngap_id)) {
         nc = amf_n1_inst->amf_ue_id_2_nas_context(amf_ue_ngap_id);
-      else {
+        stacs.update_5gmm_state(nc.get()->imsi, "5GMM-DEREGISTERED");
+      } else {
         Logger::amf_n2().warn(
             "No existed nas_context with amf_ue_ngap_id(0x%x)", amf_ue_ngap_id);
       }
-      stacs.update_5gmm_state(nc.get()->imsi, "5GMM-DEREGISTERED");
     }
   }
+  // remove UE context
+  if (ranid2uecontext.count(ran_ue_ngap_id) > 0) {
+    ranid2uecontext.erase(ran_ue_ngap_id);
+  }
 
   // Delete gNB context
   remove_gnb_context(itti_msg.assoc_id);