lte,enb,s1 handover: stop ts1 handover timers when an handover cancel occurs after the Handover preparation

srsenb/hdr/stack/s1ap/s1ap.h

@@ -107,7 +107,7 @@ public:
 
   // Stack interface
   bool
-  handle_mme_rx_msg(srsran::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags);
+       handle_mme_rx_msg(srsran::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags);
   void start_pcap(srsran::s1ap_pcap* pcap_);
 
 private:
@@ -253,6 +253,9 @@ private:
     bool send_erab_release_indication(const std::vector<uint16_t>& erabs_successfully_released);
     bool send_ue_cap_info_indication(srsran::unique_byte_buffer_t ue_radio_cap);
 
+    /// TS 36.413 8.4.5 - Handover Cancellation
+    void send_ho_cancel(const asn1::s1ap::cause_c& cause);
+
     bool was_uectxtrelease_requested() const { return release_requested; }
 
     void

srsenb/src/stack/s1ap/s1ap.cc

@@ -1292,16 +1292,7 @@ void s1ap::send_ho_cancel(uint16_t rnti, const asn1::s1ap::cause_c& cause)
     return;
   }
 
-  s1ap_pdu_c tx_pdu;
-
-  tx_pdu.set_init_msg().load_info_obj(ASN1_S1AP_ID_HO_CANCEL);
-  ho_cancel_ies_container& container = tx_pdu.init_msg().value.ho_cancel().protocol_ies;
-
-  container.mme_ue_s1ap_id.value = user_ptr->ctxt.mme_ue_s1ap_id.value();
-  container.enb_ue_s1ap_id.value = user_ptr->ctxt.enb_ue_s1ap_id;
-  container.cause.value          = cause;
-
-  sctp_send_s1ap_pdu(tx_pdu, rnti, "HandoverCancel");
+  user_ptr->send_ho_cancel(cause);
 }
 
 bool s1ap::release_erabs(uint16_t rnti, const std::vector<uint16_t>& erabs_successfully_released)
@@ -1730,6 +1721,24 @@ bool s1ap::ue::send_ue_cap_info_indication(srsran::unique_byte_buffer_t ue_radio
   return s1ap_ptr->sctp_send_s1ap_pdu(tx_pdu, ctxt.rnti, "UECapabilityInfoIndication");
 }
 
+void s1ap::ue::send_ho_cancel(const asn1::s1ap::cause_c& cause)
+{
+  // Stop handover timers
+  ts1_reloc_prep.stop();
+  ts1_reloc_overall.stop();
+
+  // Send S1AP Handover Cancel
+  s1ap_pdu_c tx_pdu;
+  tx_pdu.set_init_msg().load_info_obj(ASN1_S1AP_ID_HO_CANCEL);
+  ho_cancel_ies_container& container = tx_pdu.init_msg().value.ho_cancel().protocol_ies;
+
+  container.mme_ue_s1ap_id.value = ctxt.mme_ue_s1ap_id.value();
+  container.enb_ue_s1ap_id.value = ctxt.enb_ue_s1ap_id;
+  container.cause.value          = cause;
+
+  s1ap_ptr->sctp_send_s1ap_pdu(tx_pdu, ctxt.rnti, "HandoverCancel");
+}
+
 void s1ap::ue::set_state(s1ap_proc_id_t        next_state,
                          const erab_id_list&   erabs_updated,
                          const erab_item_list& erabs_failed_to_modify)