du,f1u: add methods to F1-U DU gateway to obtain bind address

Author: alvasMan

include/srsran/f1u/du/f1u_gateway.h

@@ -56,6 +56,8 @@ class f1u_du_gateway : public srs_du::f1u_bearer_disconnector
                                                                   srs_du::f1u_du_gateway_bearer_rx_notifier& du_rx,
                                                                   timer_factory                              timers,
                                                                   task_executor& ue_executor) = 0;
+
+  virtual expected<std::string> get_du_bind_address(uint32_t du_index) = 0;
 };
 
 } // namespace srsran::srs_du

include/srsran/f1u/du/split_connector/f1u_split_connector.h

@@ -197,6 +197,8 @@ class f1u_split_connector final : public f1u_du_gateway
 
   void remove_du_bearer(const up_transport_layer_info& dl_up_tnl_info) override;
 
+  expected<std::string> get_du_bind_address(uint32_t du_index) override;
+
 private:
   srslog::basic_logger& logger_du;
   // Key is the UL UP TNL Info (CU-CP address and UL TEID reserved by CU-CP)

include/srsran/f1u/local_connector/f1u_local_connector.h

@@ -199,6 +199,11 @@ class f1u_local_connector final : public srs_du::f1u_du_gateway, public f1u_cu_u
 
   void remove_du_bearer(const up_transport_layer_info& dl_up_tnl_info) override;
 
+  expected<std::string> get_du_bind_address(uint32_t du_index) override
+  {
+    return fmt::format("127.0.0.{}", 1 + du_index);
+  }
+
 private:
   srslog::basic_logger& logger_cu;
   srslog::basic_logger& logger_du;

include/srsran/gtpu/ngu_gateway.h

@@ -31,6 +31,12 @@ class ngu_tnl_pdu_session : public udp_network_gateway_data_handler, public netw
 public:
   ~ngu_tnl_pdu_session() override = default;
 
+  /// \brief Get the address to which the socket is bound.
+  ///
+  /// In case the gateway was configured to use a hostname,
+  /// this function can be used to get the actual IP address in string form.
+  virtual bool get_bind_address(std::string& ip_address) = 0;
+
   /// Get bind port currently being used by the NG-U TNL session for the reception of PDUs.
   /// \return If a UDP link is being used, returns the respective bind port. If the connection is local, it returns
   /// std::nullopt.

lib/f1u/du/split_connector/f1u_split_connector.cpp

@@ -74,3 +74,12 @@ void f1u_split_connector::remove_du_bearer(const up_transport_layer_info& dl_up_
   }
   logger_du.debug("Removed CU F1-U bearer with UL GTP Tunnel={}.", dl_up_tnl_info);
 }
+
+expected<std::string> f1u_split_connector::get_du_bind_address(uint32_t du_index)
+{
+  std::string ip_address;
+  if (not udp_session->get_bind_address(ip_address)) {
+    return default_error_t{};
+  }
+  return ip_address;
+}

lib/gtpu/ngu_gateway.cpp

@@ -68,6 +68,8 @@ class udp_ngu_tnl_session final : public ngu_tnl_pdu_session
     data_notifier.on_new_pdu(std::move(pdu), src_addr);
   }
 
+  bool get_bind_address(std::string& ip_address) override { return udp_gw->get_bind_address(ip_address); }
+
   std::optional<uint16_t> get_bind_port() override { return udp_gw->get_bind_port(); }
 
 private:
@@ -125,6 +127,8 @@ class no_core_ngu_tnl_pdu_session final : public ngu_tnl_pdu_session
   }
 
   std::optional<uint16_t> get_bind_port() override { return std::nullopt; }
+
+  bool get_bind_address(std::string& ip_address) override { return false; }
 };
 
 /// Implementation of the NG-U gateway for the case a local UPF stub is used.

tests/benchmarks/du_high/du_high_benchmark.cpp

@@ -339,6 +339,8 @@ class cu_up_simulator : public f1u_du_gateway
   }
 
   void remove_du_bearer(const up_transport_layer_info& dl_tnl) override {}
+
+  expected<std::string> get_du_bind_address(uint32_t du_index) override { return std::string("127.0.0.1"); }
 };
 
 /// \brief Instantiation of the DU-high workers and executors for the benchmark.

tests/test_doubles/f1u/dummy_f1u_du_gateway.h

@@ -68,6 +68,8 @@ class cu_up_simulator : public f1u_du_gateway
       }
     }
   }
+
+  expected<std::string> get_du_bind_address(uint32_t du_index) override { return std::string("127.0.0.1"); }
 };
 
 } // namespace srs_du

tests/unittests/du_manager/du_manager_test_helpers.h

@@ -196,6 +196,8 @@ class f1u_gateway_dummy : public f1u_du_gateway
     f1u_bearers.erase(bearer_it);
   }
 
+  expected<std::string> get_du_bind_address(uint32_t du_index) override { return std::string("127.0.0.1"); }
+
   std::map<up_transport_layer_info, std::map<up_transport_layer_info, f1u_gw_bearer_dummy*>> f1u_bearers;
 };