du_manager: add unit test for f1u_ext_addr

Author: FabianEckermann

tests/unittests/du_manager/procedures/ue_configuration_test.cpp

@@ -301,6 +301,55 @@ TEST_F(ue_config_tester, when_du_manager_finishes_processing_ue_config_request_t
   ASSERT_EQ(test_payload, extracted_payload);
 }
 
+TEST_F(ue_config_tester,
+       when_du_manager_finishes_processing_ue_config_request_with_f1u_ext_addr_then_mac_rlc_f1u_bearers_are_connected)
+{
+  // Add F1-U external address to the F1-U GW.
+  std::string f1u_ext_addr = "5.6.7.8";
+  f1u_gw.set_f1u_ext_addr(f1u_ext_addr);
+
+  const static std::array<uint8_t, 2> dummy_rlc_header = {0x80, 0x0};
+  byte_buffer                         test_payload     = test_helpers::create_pdcp_pdu(
+      pdcp_sn_size::size12bits, /* is_srb = */ false, 0, test_rgen::uniform_int<unsigned>(3, 100), 0);
+
+  // Run UE Configuration Procedure to completion.
+  f1ap_ue_context_update_response resp =
+      configure_ue(create_f1ap_ue_context_update_request(test_ue->ue_index, {}, {drb_id_t::drb1}));
+
+  // Check that the DL UP TNL Info has the correct F1-U external address.
+  ASSERT_EQ(resp.drbs_setup.size(), 1);
+  ASSERT_EQ(resp.drbs_setup[0].dluptnl_info_list.size(), 1);
+  ASSERT_EQ(resp.drbs_setup[0].dluptnl_info_list[0].tp_address,
+            transport_layer_address::create_from_string(f1u_ext_addr));
+
+  srs_du::f1u_gw_bearer_dummy* bearer = f1u_gw.f1u_bearers.begin()->second.begin()->second;
+
+  // Forward MAC Rx SDU through DRB1 (UL).
+  // > Add dummy RLC data header.
+  byte_buffer mac_sdu = byte_buffer::create(dummy_rlc_header).value();
+  // > Append data buffer.
+  ASSERT_TRUE(mac_sdu.append(test_payload.copy()));
+  // > Push MAC Rx SDU through MAC logical channel.
+  mac.last_ue_reconf_msg->bearers_to_addmod[0].ul_bearer->on_new_sdu({mac_sdu.copy()});
+  // > Check arrival of F1-U Tx SDU to F1-U bearer.
+  auto last_sdu = bearer->last_sdu->t_pdu->deep_copy().value();
+  ASSERT_EQ(test_payload, last_sdu);
+
+  // Forward F1-U Rx SDU through DRB1 (DL).
+  // > Create data buffer.
+  nru_dl_message rx_sdu;
+  rx_sdu.t_pdu = test_payload.copy();
+  // > Push F1-U Rx SDU through F1-U bearer Rx SDU notifier.
+  bearer->du_rx.on_new_pdu(std::move(rx_sdu));
+
+  // > Check arrival of MAC Tx SDU to MAC logical channel.
+  std::vector<uint8_t> mac_tx_sdu(test_payload.length() + dummy_rlc_header.size());
+  unsigned             nwritten = mac.last_ue_reconf_msg->bearers_to_addmod[0].dl_bearer->on_new_tx_sdu(mac_tx_sdu);
+  byte_buffer          extracted_payload =
+      byte_buffer::create(mac_tx_sdu.begin() + dummy_rlc_header.size(), mac_tx_sdu.begin() + nwritten).value();
+  ASSERT_EQ(test_payload, extracted_payload);
+}
+
 TEST_F(ue_config_tester, when_f1u_gw_fails_to_create_bearer_then_drb_is_included_in_failed_list)
 {
   this->f1u_gw.next_bearer_is_created = false;