cu_cp,ngap: add unittest for handling of ue cap info request in dl nas transport message

Author: FabianEckermann

tests/unittests/ngap/ngap_nas_message_test.cpp

@@ -40,6 +40,12 @@ class ngap_nas_message_routine_test : public ngap_test
 
   bool was_dl_nas_transport_dropped(const test_ue& ue) const { return ue.rrc_ue_dl_nas_handler.last_nas_pdu.empty(); }
 
+  bool was_ue_radio_capability_info_indication_sent() const
+  {
+    return n2_gw.last_ngap_msgs.back().pdu.init_msg().value.type() ==
+           asn1::ngap::ngap_elem_procs_o::init_msg_c::types_opts::ue_radio_cap_info_ind;
+  }
+
   bool was_ul_nas_transport_forwarded() const
   {
     return n2_gw.last_ngap_msgs.back().pdu.init_msg().value.type() ==
@@ -125,6 +131,29 @@ TEST_F(ngap_nas_message_routine_test, when_no_ue_present_dl_nas_transport_is_dro
   ASSERT_TRUE(was_error_indication_sent());
 }
 
+/// Test DL NAS transport handling
+TEST_F(ngap_nas_message_routine_test,
+       when_dl_nas_transport_contains_ue_cap_info_request_then_ue_radio_cap_info_indication_is_sent)
+{
+  // Test preamble
+  ue_index_t ue_index = this->start_procedure();
+
+  auto& ue     = test_ues.at(ue_index);
+  ue.amf_ue_id = uint_to_amf_ue_id(
+      test_rgen::uniform_int<uint64_t>(amf_ue_id_to_uint(amf_ue_id_t::min), amf_ue_id_to_uint(amf_ue_id_t::max)));
+
+  // Inject DL NAS transport message from AMF
+  ngap_message dl_nas_transport =
+      generate_downlink_nas_transport_message_with_ue_cap_info_request(ue.amf_ue_id.value(), ue.ran_ue_id.value());
+  ngap->handle_message(dl_nas_transport);
+
+  // Check that RRC notifier was called
+  ASSERT_TRUE(was_dl_nas_transport_forwarded(ue));
+
+  // Check that UE Radio Capability Info Indication was sent to AMF
+  ASSERT_TRUE(was_ue_radio_capability_info_indication_sent());
+}
+
 /// Test UL NAS transport handling
 TEST_F(ngap_nas_message_routine_test, when_ue_present_and_amf_set_ul_nas_transport_is_forwared)
 {

tests/unittests/ngap/ngap_test_messages.cpp

@@ -181,6 +181,19 @@ ngap_message srsran::srs_cu_cp::generate_downlink_nas_transport_message(amf_ue_i
   return dl_nas_transport;
 }
 
+ngap_message srsran::srs_cu_cp::generate_downlink_nas_transport_message_with_ue_cap_info_request(amf_ue_id_t amf_ue_id,
+                                                                                                 ran_ue_id_t ran_ue_id,
+                                                                                                 byte_buffer nas_pdu)
+{
+  ngap_message dl_nas_transport = generate_downlink_nas_transport_message(amf_ue_id, ran_ue_id, std::move(nas_pdu));
+
+  auto& dl_nas_transport_msg                        = dl_nas_transport.pdu.init_msg().value.dl_nas_transport();
+  dl_nas_transport_msg->ue_cap_info_request_present = true;
+  dl_nas_transport_msg->ue_cap_info_request         = ue_cap_info_request_opts::options::requested;
+
+  return dl_nas_transport;
+}
+
 cu_cp_ul_nas_transport srsran::srs_cu_cp::generate_ul_nas_transport_message(ue_index_t ue_index)
 {
   cu_cp_ul_nas_transport ul_nas_transport = {};

tests/unittests/ngap/ngap_test_messages.h

@@ -104,6 +104,11 @@ cu_cp_initial_ue_message generate_initial_ue_message(ue_index_t ue_index);
 ngap_message
 generate_downlink_nas_transport_message(amf_ue_id_t amf_ue_id, ran_ue_id_t ran_ue_id, byte_buffer nas_pdu = {});
 
+/// \brief Generate a dummy DL NAS Transport Message with UE Cap Info Request.
+ngap_message generate_downlink_nas_transport_message_with_ue_cap_info_request(amf_ue_id_t amf_ue_id,
+                                                                              ran_ue_id_t ran_ue_id,
+                                                                              byte_buffer nas_pdu = {});
+
 /// \brief Generate a dummy UL NAS Transport Message.
 cu_cp_ul_nas_transport generate_ul_nas_transport_message(ue_index_t ue_index);