e2ap: splitting the e2 response function into success & failure functions, cleaning up e2 setup procedure

Author: yagoda

include/srsran/e2/e2.h

@@ -56,16 +56,10 @@ class e2_connection_manager
 public:
   virtual ~e2_connection_manager() = default;
 
-  /// \brief Creates and transmits the E2 Setup outcome to the CU-UP.
-  /// \param[in] msg The cu_up_e1_setup_response_message to transmit.
-  /// \remark The CU transmits the E2SetupResponse/E2SetupFailure as per______.
-  virtual void handle_e2_setup_response(const e2_setup_response_message& msg) = 0;
-
   /// \brief Initiates the E2 Setup procedure as per _____
-  /// \param[in] request The E1SetupRequest message to transmit.
+  /// \param[in] request The E2SetupRequest message to transmit.
   /// \return Returns a e2_setup_response_message struct with the success member set to 'true' in case of a
   /// successful outcome, 'false' otherwise.
-  /// \remark The CU transmits the E2SetupRequest as per ______.
   /// and awaits the response. If a E2SetupFailure is received the E2 will handle the failure.
   virtual async_task<e2_setup_response_message> handle_e2_setup_request(e2_setup_request_message& request) = 0;
 };

lib/e2/common/e2_impl.cpp

@@ -57,9 +57,12 @@ void e2_impl::handle_e2_setup_response(const e2_setup_response_message& msg)
 {
   e2_message e2_msg;
   if (msg.success) {
-    logger.info("Transmitting E2 Setup Response message");
+    logger.info("Received E2 Setup Response message");
     e2_msg.pdu.set_successful_outcome().load_info_obj(ASN1_E2AP_ID_E2SETUP);
     e2_msg.pdu.successful_outcome().value.e2setup_resp() = msg.response;
+  } else {
+    logger.error("E2 Setup Failure message received");
+    return;
   }
   if (e2_msg.pdu.successful_outcome().value.e2setup_resp()->ra_nfunctions_accepted_present) {
     for (unsigned i = 0, e = e2_msg.pdu.successful_outcome().value.e2setup_resp()->ra_nfunctions_accepted.value.size();
@@ -74,7 +77,19 @@ void e2_impl::handle_e2_setup_response(const e2_setup_response_message& msg)
       set_allowed_ran_functions(id);
     }
   }
-  pdu_notifier.on_new_message(e2_msg);
+}
+
+void e2_impl::handle_e2_setup_failure(const e2_setup_response_message& msg)
+{
+  e2_message e2_msg;
+  if (!msg.success) {
+    logger.info("Transmitting E2 Setup Failure message");
+    e2_msg.pdu.set_unsuccessful_outcome().load_info_obj(ASN1_E2AP_ID_E2SETUP);
+    e2_msg.pdu.unsuccessful_outcome().value.e2setup_fail() = msg.failure;
+  } else {
+    logger.error("E2 Setup Response message received");
+    return;
+  }
 }
 
 void e2_impl::handle_ric_subscription_request(const asn1::e2ap::ricsubscription_request_s& msg)
@@ -145,7 +160,7 @@ void e2_impl::handle_successful_outcome(const asn1::e2ap::successful_outcome_s&
       if (not events->transactions.set(transaction_id.value(), outcome)) {
         logger.warning("Unrecognized transaction id={}", transaction_id.value());
       }
-      handle_e2_setup_response({outcome.value.e2setup_resp()});
+      handle_e2_setup_response({outcome.value.e2setup_resp(), {}, true});
     } break;
     default:
       logger.error("Invalid E2AP successful outcome message type");
@@ -167,6 +182,7 @@ void e2_impl::handle_unsuccessful_outcome(const asn1::e2ap::unsuccessful_outcome
       if (not events->transactions.set(transaction_id.value(), outcome)) {
         logger.warning("Unrecognized transaction id={}", transaction_id.value());
       }
+      handle_e2_setup_failure({{}, outcome.value.e2setup_fail(), false});
     } break;
     default:
       logger.error("Invalid E2AP unsuccessful outcome message type");

lib/e2/common/e2_impl.h

@@ -31,8 +31,6 @@ class e2_impl final : public e2_interface
   /// E2 connection manager functions.
   async_task<e2_setup_response_message> handle_e2_setup_request(e2_setup_request_message& request) override;
 
-  void handle_e2_setup_response(const e2_setup_response_message& msg) override;
-
   /// E2_event_ handler functions.
   void handle_connection_loss() override {}
 
@@ -59,6 +57,14 @@ class e2_impl final : public e2_interface
   /// \param[in] msg The received ric subscription request message.
   void handle_ric_subscription_request(const asn1::e2ap::ricsubscription_request_s& msg);
 
+  /// \brief handle e2 setup response message from the ric interface.
+  /// @param[in] msg  The received e2 setup response message.
+  void handle_e2_setup_response(const e2_setup_response_message& msg);
+
+  /// \brief handle e2 setup failure message from the ric interface.
+  /// \param[in] msg  The received e2 setup failure message.
+  void handle_e2_setup_failure(const e2_setup_response_message& msg);
+
   /// \brief set the allowed ran functions from the e2 setuo response message.
   /// \param[in] msg The received ran_function_id from the e2 setup response message.
   void set_allowed_ran_functions(const uint16_t ran_function_id);

lib/e2/procedures/e2_setup_procedure.cpp

@@ -30,10 +30,10 @@ void e2_setup_procedure::operator()(coro_context<async_task<e2_setup_response_me
   while (true) {
     transaction = ev_mng.transactions.create_transaction();
 
-    // Send request to CU-UP.
+    // Send request to RIC interface.
     send_e2_setup_request();
 
-    // Await CU response.
+    // Await RIC response.
     CORO_AWAIT(transaction);
 
     if (not retry_required()) {