Merge branch 'fix_n2_ho_uectxrelease' into 'fix_n2_handover'

Fix: ue nas context deleted after successful handover

See merge request oai/cn5g/oai-cn5g-amf!204

src/amf-app/amf_n2.cpp

@@ -1309,6 +1309,28 @@ void amf_n2::handle_itti_message(itti_ue_context_release_complete& itti_msg) {
     return;
   }
 
+  std::shared_ptr<ue_ngap_context> unc = {};
+  if (!amf_ue_id_2_ue_ngap_context(amf_ue_ngap_id, unc)) {
+    Logger::amf_app().error(
+        "No UE NGAP context for amf_ngap_id %s, exit", amf_ue_ngap_id);
+    return;
+  }
+
+  std::shared_ptr<gnb_context> gc = {};
+    if (!assoc_id_2_gnb_context(itti_msg.assoc_id, gc)) {
+      Logger::amf_n2().error(
+          "gNB with assoc_id (%d) is illegal", itti_msg.assoc_id);
+      return;
+    }
+
+  //verify release cause -> if HandoverSuccessful no further operations required
+  if(unc->release_cause == Ngap_CauseRadioNetwork_successful_handover && gc->gnb_id == unc->release_gnb){
+    remove_ran_ue_ngap_id_2_ngap_context(ran_ue_ngap_id, gc->gnb_id);
+    unc->release_cause = 0;
+    return;
+  }
+
+
   // Change UE status from CM-CONNECTED to CM-IDLE
   std::shared_ptr<nas_context> nc = {};
   if (!amf_n1_inst->amf_ue_id_2_nas_context(amf_ue_ngap_id, nc)) {
@@ -2024,17 +2046,30 @@ void amf_n2::handle_itti_message(itti_handover_notify& itti_msg) {
   sctp_s_38412.sctp_send_msg(unc->gnb_assoc_id, 0, &b);
   bdestroy_wrapper(&b);
 
-  if (!amf_ue_id_2_ue_ngap_context(amf_ue_ngap_id, unc)) {
-    Logger::amf_n2().error(
-        "No UE NGAP context with amf_ue_ngap_id (" AMF_UE_NGAP_ID_FMT ")",
-        amf_ue_ngap_id);
+  string ue_context_key =
+      conv::get_ue_context_key(unc->ran_ue_ngap_id, amf_ue_ngap_id);
+  std::shared_ptr<ue_context> uc = {};
+  if (!amf_app_inst->ran_amf_id_2_ue_context(ue_context_key, uc)) {
+    Logger::amf_app().error(
+        "No UE context for ran_amf_id %s, exit", ue_context_key.c_str());
     return;
   }
 
+  //update the NGAP Context
+  unc->release_cause         = Ngap_CauseRadioNetwork_successful_handover;
+  unc->release_gnb           = uc->gnb_id;
   unc->ran_ue_ngap_id        = ran_ue_ngap_id;  // store new RAN ID
   unc->target_ran_ue_ngap_id = 0;               // Clear target RAN ID
   unc->ng_ue_state           = NGAP_UE_CONNECTED;
   unc->gnb_assoc_id          = itti_msg.assoc_id;  // update serving gNB
+
+  //update NAS Context
+  nc->ran_ue_ngap_id = ran_ue_ngap_id;
+ 
+  //update User Context
+  uc->ran_ue_ngap_id = ran_ue_ngap_id;
+  uc->gnb_id = gc->gnb_id;
+
   set_ran_ue_ngap_id_2_ue_ngap_context(ran_ue_ngap_id, gc->gnb_id, unc);
 }
 

src/contexts/ue_ngap_context.hpp

@@ -48,6 +48,8 @@ class ue_ngap_context {
     sctp_stream_recv = {};
     sctp_stream_send = {};
 
+    release_gnb         = {};
+    release_cause       = {};
     gnb_assoc_id        = {};
     target_gnb_assoc_id = {};
     ueContextRequest    = false;
@@ -91,6 +93,10 @@ class ue_ngap_context {
   uint8_t ncc;  // Next Hop Chaining Counter
 
   OCTET_STRING_t initialUEMsg;
+
+  //Release Command Cause and source gNB ID in case of HO
+  Ngap_CauseRadioNetwork_t release_cause;
+  uint32_t release_gnb;
 };
 
 #endif