rpcsrv: carefully store Oracle service

And simplify atomic service value stored by RPC server. Oracle service can
either be an untyped nil or be the proper non-nil *oracle.Oracle.
Otherwise `submitoracleresponse` RPC handler doesn't work properly.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>

cli/server/server.go

@@ -359,7 +359,14 @@ func resetDB(ctx *cli.Context) error {
 	return nil
 }
 
-func mkOracle(config config.OracleConfiguration, magic netmode.Magic, chain *core.Blockchain, serv *network.Server, log *zap.Logger) (*oracle.Oracle, error) {
+// oracleService is an interface representing Oracle service with network.Service
+// capabilities and ability to submit oracle responses.
+type oracleService interface {
+	rpcsrv.OracleHandler
+	network.Service
+}
+
+func mkOracle(config config.OracleConfiguration, magic netmode.Magic, chain *core.Blockchain, serv *network.Server, log *zap.Logger) (oracleService, error) {
 	if !config.Enabled {
 		return nil, nil
 	}

pkg/services/rpcsrv/server.go

@@ -254,7 +254,8 @@ var invalidBlockHeightError = func(index int, height int) *neorpc.Error {
 	return neorpc.NewRPCError("Invalid block height", fmt.Sprintf("param at index %d should be greater than or equal to 0 and less then or equal to current block height, got: %d", index, height))
 }
 
-// New creates a new Server struct.
+// New creates a new Server struct. Pay attention that orc is expected to be either
+// untyped nil or non-nil structure implementing OracleHandler interface.
 func New(chain Ledger, conf config.RPC, coreServer *network.Server,
 	orc OracleHandler, log *zap.Logger, errChan chan<- error) Server {
 	addrs := conf.GetAddresses()
@@ -293,7 +294,7 @@ func New(chain Ledger, conf config.RPC, coreServer *network.Server,
 	}
 	var oracleWrapped = new(atomic.Value)
 	if orc != nil {
-		oracleWrapped.Store(&orc)
+		oracleWrapped.Store(orc)
 	}
 	var wsOriginChecker func(*http.Request) bool
 	if conf.EnableCORSWorkaround {
@@ -445,7 +446,7 @@ func (s *Server) Shutdown() {
 
 // SetOracleHandler allows to update oracle handler used by the Server.
 func (s *Server) SetOracleHandler(orc OracleHandler) {
-	s.oracle.Store(&orc)
+	s.oracle.Store(orc)
 }
 
 func (s *Server) handleHTTPRequest(w http.ResponseWriter, httpRequest *http.Request) {
@@ -2461,10 +2462,11 @@ func getRelayResult(err error, hash util.Uint256) (any, *neorpc.Error) {
 }
 
 func (s *Server) submitOracleResponse(ps params.Params) (any, *neorpc.Error) {
-	oracle := s.oracle.Load().(*OracleHandler)
+	oraclePtr := s.oracle.Load()
-	if oracle == nil || *oracle == nil {
+	if oraclePtr == nil {
 		return nil, neorpc.NewRPCError("Oracle is not enabled", "")
 	}
+	oracle := oraclePtr.(OracleHandler)
 	var pub *keys.PublicKey
 	pubBytes, err := ps.Value(0).GetBytesBase64()
 	if err == nil {
@@ -2489,7 +2491,7 @@ func (s *Server) submitOracleResponse(ps params.Params) (any, *neorpc.Error) {
 	if !pub.Verify(msgSig, hash.Sha256(data).BytesBE()) {
 		return nil, neorpc.NewRPCError("Invalid request signature", "")
 	}
-	(*oracle).AddResponse(pub, uint64(reqID), txSig)
+	oracle.AddResponse(pub, uint64(reqID), txSig)
 	return json.RawMessage([]byte("{}")), nil
 }
 

pkg/services/rpcsrv/server_helper_test.go

@@ -29,7 +29,7 @@ const (
 	notaryPass = "one"
 )
 
-func getUnitTestChain(t testing.TB, enableOracle bool, enableNotary bool, disableIteratorSessions bool) (*core.Blockchain, *oracle.Oracle, config.Config, *zap.Logger) {
+func getUnitTestChain(t testing.TB, enableOracle bool, enableNotary bool, disableIteratorSessions bool) (*core.Blockchain, OracleHandler, config.Config, *zap.Logger) {
 	return getUnitTestChainWithCustomConfig(t, enableOracle, enableNotary, func(cfg *config.Config) {
 		if disableIteratorSessions {
 			cfg.ApplicationConfiguration.RPC.SessionEnabled = false
@@ -56,7 +56,7 @@ func getUnitTestChain(t testing.TB, enableOracle bool, enableNotary bool, disabl
 		}
 	})
 }
-func getUnitTestChainWithCustomConfig(t testing.TB, enableOracle bool, enableNotary bool, customCfg func(configuration *config.Config)) (*core.Blockchain, *oracle.Oracle, config.Config, *zap.Logger) {
+func getUnitTestChainWithCustomConfig(t testing.TB, enableOracle bool, enableNotary bool, customCfg func(configuration *config.Config)) (*core.Blockchain, OracleHandler, config.Config, *zap.Logger) {
 	net := netmode.UnitTestNet
 	configPath := "../../../config"
 	cfg, err := config.Load(configPath, net)
@@ -70,7 +70,7 @@ func getUnitTestChainWithCustomConfig(t testing.TB, enableOracle bool, enableNot
 	chain, err := core.NewBlockchain(memoryStore, cfg.Blockchain(), logger)
 	require.NoError(t, err, "could not create chain")
 
-	var orc *oracle.Oracle
+	var orc OracleHandler
 	if enableOracle {
 		orc, err = oracle.NewOracle(oracle.Config{
 			Log:     logger,
@@ -79,7 +79,7 @@ func getUnitTestChainWithCustomConfig(t testing.TB, enableOracle bool, enableNot
 			Chain:   chain,
 		})
 		require.NoError(t, err)
-		chain.SetOracle(orc)
+		chain.SetOracle(orc.(*oracle.Oracle))
 	}
 
 	go chain.Run()
@@ -115,7 +115,7 @@ func initClearServerWithServices(t testing.TB, needOracle bool, needNotary bool,
 	return wrapUnitTestChain(t, chain, orc, cfg, logger)
 }
 
-func wrapUnitTestChain(t testing.TB, chain *core.Blockchain, orc *oracle.Oracle, cfg config.Config, logger *zap.Logger) (*core.Blockchain, *Server, *httptest.Server) {
+func wrapUnitTestChain(t testing.TB, chain *core.Blockchain, orc OracleHandler, cfg config.Config, logger *zap.Logger) (*core.Blockchain, *Server, *httptest.Server) {
 	serverConfig, err := network.NewServerConfig(cfg)
 	require.NoError(t, err)
 	serverConfig.UserAgent = fmt.Sprintf(config.UserAgentFormat, "0.98.6-test")