package server import ( "bytes" "context" "crypto/elliptic" "encoding/binary" "encoding/hex" "encoding/json" "errors" "fmt" "math" "math/big" "net" "net/http" "strconv" "strings" "sync" "time" "github.com/gorilla/websocket" "github.com/nspcc-dev/neo-go/pkg/config/netmode" "github.com/nspcc-dev/neo-go/pkg/core" "github.com/nspcc-dev/neo-go/pkg/core/block" "github.com/nspcc-dev/neo-go/pkg/core/blockchainer" "github.com/nspcc-dev/neo-go/pkg/core/fee" "github.com/nspcc-dev/neo-go/pkg/core/interop" "github.com/nspcc-dev/neo-go/pkg/core/interop/iterator" "github.com/nspcc-dev/neo-go/pkg/core/mempoolevent" "github.com/nspcc-dev/neo-go/pkg/core/mpt" "github.com/nspcc-dev/neo-go/pkg/core/native" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/storage" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/crypto/hash" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" "github.com/nspcc-dev/neo-go/pkg/encoding/address" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/network" "github.com/nspcc-dev/neo-go/pkg/network/payload" "github.com/nspcc-dev/neo-go/pkg/rpc" "github.com/nspcc-dev/neo-go/pkg/rpc/request" "github.com/nspcc-dev/neo-go/pkg/rpc/response" "github.com/nspcc-dev/neo-go/pkg/rpc/response/result" "github.com/nspcc-dev/neo-go/pkg/rpc/response/result/subscriptions" "github.com/nspcc-dev/neo-go/pkg/services/oracle" "github.com/nspcc-dev/neo-go/pkg/services/oracle/broadcaster" "github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag" "github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm/emit" "github.com/nspcc-dev/neo-go/pkg/vm/opcode" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" "go.uber.org/atomic" "go.uber.org/zap" ) type ( // Server represents the JSON-RPC 2.0 server. Server struct { *http.Server chain blockchainer.Blockchainer config rpc.Config // wsReadLimit represents web-socket message limit for a receiving side. wsReadLimit int64 network netmode.Magic stateRootEnabled bool coreServer *network.Server oracle *oracle.Oracle log *zap.Logger https *http.Server shutdown chan struct{} started *atomic.Bool errChan chan error subsLock sync.RWMutex subscribers map[*subscriber]bool blockSubs int executionSubs int notificationSubs int transactionSubs int notaryRequestSubs int blockCh chan *block.Block executionCh chan *state.AppExecResult notificationCh chan *subscriptions.NotificationEvent transactionCh chan *transaction.Transaction notaryRequestCh chan mempoolevent.Event } ) const ( // Disconnection timeout. wsPongLimit = 60 * time.Second // Ping period for connection liveness check. wsPingPeriod = wsPongLimit / 2 // Write deadline. wsWriteLimit = wsPingPeriod / 2 // Maximum number of subscribers per Server. Each websocket client is // treated like a subscriber, so technically it's a limit on websocket // connections. maxSubscribers = 64 // Maximum number of elements for get*transfers requests. maxTransfersLimit = 1000 ) var rpcHandlers = map[string]func(*Server, request.Params) (interface{}, *response.Error){ "calculatenetworkfee": (*Server).calculateNetworkFee, "findstates": (*Server).findStates, "getapplicationlog": (*Server).getApplicationLog, "getbestblockhash": (*Server).getBestBlockHash, "getblock": (*Server).getBlock, "getblockcount": (*Server).getBlockCount, "getblockhash": (*Server).getBlockHash, "getblockheader": (*Server).getBlockHeader, "getblockheadercount": (*Server).getBlockHeaderCount, "getblocksysfee": (*Server).getBlockSysFee, "getcommittee": (*Server).getCommittee, "getconnectioncount": (*Server).getConnectionCount, "getcontractstate": (*Server).getContractState, "getnativecontracts": (*Server).getNativeContracts, "getnep11balances": (*Server).getNEP11Balances, "getnep11properties": (*Server).getNEP11Properties, "getnep11transfers": (*Server).getNEP11Transfers, "getnep17balances": (*Server).getNEP17Balances, "getnep17transfers": (*Server).getNEP17Transfers, "getpeers": (*Server).getPeers, "getproof": (*Server).getProof, "getrawmempool": (*Server).getRawMempool, "getrawtransaction": (*Server).getrawtransaction, "getstate": (*Server).getState, "getstateheight": (*Server).getStateHeight, "getstateroot": (*Server).getStateRoot, "getstorage": (*Server).getStorage, "gettransactionheight": (*Server).getTransactionHeight, "getunclaimedgas": (*Server).getUnclaimedGas, "getnextblockvalidators": (*Server).getNextBlockValidators, "getversion": (*Server).getVersion, "invokefunction": (*Server).invokeFunction, "invokefunctionhistoric": (*Server).invokeFunctionHistoric, "invokescript": (*Server).invokescript, "invokescripthistoric": (*Server).invokescripthistoric, "invokecontractverify": (*Server).invokeContractVerify, "invokecontractverifyhistoric": (*Server).invokeContractVerifyHistoric, "sendrawtransaction": (*Server).sendrawtransaction, "submitblock": (*Server).submitBlock, "submitnotaryrequest": (*Server).submitNotaryRequest, "submitoracleresponse": (*Server).submitOracleResponse, "validateaddress": (*Server).validateAddress, "verifyproof": (*Server).verifyProof, } var rpcWsHandlers = map[string]func(*Server, request.Params, *subscriber) (interface{}, *response.Error){ "subscribe": (*Server).subscribe, "unsubscribe": (*Server).unsubscribe, } var invalidBlockHeightError = func(index int, height int) *response.Error { return response.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)) } // upgrader is a no-op websocket.Upgrader that reuses HTTP server buffers and // doesn't set any Error function. var upgrader = websocket.Upgrader{} // New creates a new Server struct. func New(chain blockchainer.Blockchainer, conf rpc.Config, coreServer *network.Server, orc *oracle.Oracle, log *zap.Logger, errChan chan error) Server { httpServer := &http.Server{ Addr: conf.Address + ":" + strconv.FormatUint(uint64(conf.Port), 10), } var tlsServer *http.Server if cfg := conf.TLSConfig; cfg.Enabled { tlsServer = &http.Server{ Addr: net.JoinHostPort(cfg.Address, strconv.FormatUint(uint64(cfg.Port), 10)), } } if orc != nil { orc.SetBroadcaster(broadcaster.New(orc.MainCfg, log)) } return Server{ Server: httpServer, chain: chain, config: conf, wsReadLimit: int64(chain.GetConfig().MaxBlockSize*4)/3 + 1024, // Enough for Base64-encoded content of `submitblock` and `submitp2pnotaryrequest`. network: chain.GetConfig().Magic, stateRootEnabled: chain.GetConfig().StateRootInHeader, coreServer: coreServer, log: log, oracle: orc, https: tlsServer, shutdown: make(chan struct{}), started: atomic.NewBool(false), errChan: errChan, subscribers: make(map[*subscriber]bool), // These are NOT buffered to preserve original order of events. blockCh: make(chan *block.Block), executionCh: make(chan *state.AppExecResult), notificationCh: make(chan *subscriptions.NotificationEvent), transactionCh: make(chan *transaction.Transaction), notaryRequestCh: make(chan mempoolevent.Event), } } // Name returns service name. func (s *Server) Name() string { return "rpc" } // Start creates a new JSON-RPC server listening on the configured port. It creates // goroutines needed internally and it returns its errors via errChan passed to New(). func (s *Server) Start() { if !s.config.Enabled { s.log.Info("RPC server is not enabled") return } if !s.started.CAS(false, true) { s.log.Info("RPC server already started") return } s.Handler = http.HandlerFunc(s.handleHTTPRequest) s.log.Info("starting rpc-server", zap.String("endpoint", s.Addr)) go s.handleSubEvents() if cfg := s.config.TLSConfig; cfg.Enabled { s.https.Handler = http.HandlerFunc(s.handleHTTPRequest) s.log.Info("starting rpc-server (https)", zap.String("endpoint", s.https.Addr)) go func() { ln, err := net.Listen("tcp", s.https.Addr) if err != nil { s.errChan <- err return } s.https.Addr = ln.Addr().String() err = s.https.ServeTLS(ln, cfg.CertFile, cfg.KeyFile) if err != http.ErrServerClosed { s.log.Error("failed to start TLS RPC server", zap.Error(err)) s.errChan <- err } }() } ln, err := net.Listen("tcp", s.Addr) if err != nil { s.errChan <- err return } s.Addr = ln.Addr().String() // set Addr to the actual address go func() { err = s.Serve(ln) if err != http.ErrServerClosed { s.log.Error("failed to start RPC server", zap.Error(err)) s.errChan <- err } }() } // Shutdown stops the RPC server. It can only be called once. func (s *Server) Shutdown() { if !s.started.Load() { return } // Signal to websocket writer routines and handleSubEvents. close(s.shutdown) if s.config.TLSConfig.Enabled { s.log.Info("shutting down RPC server (https)", zap.String("endpoint", s.https.Addr)) err := s.https.Shutdown(context.Background()) if err != nil { s.log.Warn("error during RPC (https) server shutdown", zap.Error(err)) } } s.log.Info("shutting down RPC server", zap.String("endpoint", s.Addr)) err := s.Server.Shutdown(context.Background()) if err != nil { s.log.Warn("error during RPC (http) server shutdown", zap.Error(err)) } // Wait for handleSubEvents to finish. <-s.executionCh } func (s *Server) handleHTTPRequest(w http.ResponseWriter, httpRequest *http.Request) { req := request.NewRequest() if httpRequest.URL.Path == "/ws" && httpRequest.Method == "GET" { // Technically there is a race between this check and // s.subscribers modification 20 lines below, but it's tiny // and not really critical to bother with it. Some additional // clients may sneak in, no big deal. s.subsLock.RLock() numOfSubs := len(s.subscribers) s.subsLock.RUnlock() if numOfSubs >= maxSubscribers { s.writeHTTPErrorResponse( request.NewIn(), w, response.NewInternalServerError("websocket users limit reached"), ) return } ws, err := upgrader.Upgrade(w, httpRequest, nil) if err != nil { s.log.Info("websocket connection upgrade failed", zap.Error(err)) return } resChan := make(chan abstractResult) // response.abstract or response.abstractBatch subChan := make(chan *websocket.PreparedMessage, notificationBufSize) subscr := &subscriber{writer: subChan, ws: ws} s.subsLock.Lock() s.subscribers[subscr] = true s.subsLock.Unlock() go s.handleWsWrites(ws, resChan, subChan) s.handleWsReads(ws, resChan, subscr) return } if httpRequest.Method != "POST" { s.writeHTTPErrorResponse( request.NewIn(), w, response.NewInvalidParamsError(fmt.Sprintf("invalid method '%s', please retry with 'POST'", httpRequest.Method)), ) return } err := req.DecodeData(httpRequest.Body) if err != nil { s.writeHTTPErrorResponse(request.NewIn(), w, response.NewParseError(err.Error())) return } resp := s.handleRequest(req, nil) s.writeHTTPServerResponse(req, w, resp) } func (s *Server) handleRequest(req *request.Request, sub *subscriber) abstractResult { if req.In != nil { req.In.Method = escapeForLog(req.In.Method) // No valid method name will be changed by it. return s.handleIn(req.In, sub) } resp := make(abstractBatch, len(req.Batch)) for i, in := range req.Batch { in.Method = escapeForLog(in.Method) // No valid method name will be changed by it. resp[i] = s.handleIn(&in, sub) } return resp } func (s *Server) handleIn(req *request.In, sub *subscriber) abstract { var res interface{} var resErr *response.Error if req.JSONRPC != request.JSONRPCVersion { return s.packResponse(req, nil, response.NewInvalidParamsError(fmt.Sprintf("problem parsing JSON: invalid version, expected 2.0 got '%s'", req.JSONRPC))) } reqParams := request.Params(req.RawParams) s.log.Debug("processing rpc request", zap.String("method", req.Method), zap.Stringer("params", reqParams)) incCounter(req.Method) resErr = response.NewMethodNotFoundError(fmt.Sprintf("method %q not supported", req.Method)) handler, ok := rpcHandlers[req.Method] if ok { res, resErr = handler(s, reqParams) } else if sub != nil { handler, ok := rpcWsHandlers[req.Method] if ok { res, resErr = handler(s, reqParams, sub) } } return s.packResponse(req, res, resErr) } func (s *Server) handleWsWrites(ws *websocket.Conn, resChan <-chan abstractResult, subChan <-chan *websocket.PreparedMessage) { pingTicker := time.NewTicker(wsPingPeriod) eventloop: for { select { case <-s.shutdown: break eventloop case event, ok := <-subChan: if !ok { break eventloop } if err := ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil { break eventloop } if err := ws.WritePreparedMessage(event); err != nil { break eventloop } case res, ok := <-resChan: if !ok { break eventloop } if err := ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil { break eventloop } if err := ws.WriteJSON(res); err != nil { break eventloop } case <-pingTicker.C: if err := ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil { break eventloop } if err := ws.WriteMessage(websocket.PingMessage, []byte{}); err != nil { break eventloop } } } ws.Close() pingTicker.Stop() // Drain notification channel as there might be some goroutines blocked // on it. drainloop: for { select { case _, ok := <-subChan: if !ok { break drainloop } default: break drainloop } } } func (s *Server) handleWsReads(ws *websocket.Conn, resChan chan<- abstractResult, subscr *subscriber) { ws.SetReadLimit(s.wsReadLimit) err := ws.SetReadDeadline(time.Now().Add(wsPongLimit)) ws.SetPongHandler(func(string) error { return ws.SetReadDeadline(time.Now().Add(wsPongLimit)) }) requestloop: for err == nil { req := request.NewRequest() err := ws.ReadJSON(req) if err != nil { break } res := s.handleRequest(req, subscr) res.RunForErrors(func(jsonErr *response.Error) { s.logRequestError(req, jsonErr) }) select { case <-s.shutdown: break requestloop case resChan <- res: } } s.subsLock.Lock() delete(s.subscribers, subscr) for _, e := range subscr.feeds { if e.event != response.InvalidEventID { s.unsubscribeFromChannel(e.event) } } s.subsLock.Unlock() close(resChan) ws.Close() } func (s *Server) getBestBlockHash(_ request.Params) (interface{}, *response.Error) { return "0x" + s.chain.CurrentBlockHash().StringLE(), nil } func (s *Server) getBlockCount(_ request.Params) (interface{}, *response.Error) { return s.chain.BlockHeight() + 1, nil } func (s *Server) getBlockHeaderCount(_ request.Params) (interface{}, *response.Error) { return s.chain.HeaderHeight() + 1, nil } func (s *Server) getConnectionCount(_ request.Params) (interface{}, *response.Error) { return s.coreServer.PeerCount(), nil } func (s *Server) blockHashFromParam(param *request.Param) (util.Uint256, *response.Error) { var ( hash util.Uint256 err error ) if param == nil { return hash, response.ErrInvalidParams } if hash, err = param.GetUint256(); err != nil { num, respErr := s.blockHeightFromParam(param) if respErr != nil { return hash, respErr } hash = s.chain.GetHeaderHash(num) } return hash, nil } func (s *Server) getBlock(reqParams request.Params) (interface{}, *response.Error) { param := reqParams.Value(0) hash, respErr := s.blockHashFromParam(param) if respErr != nil { return nil, respErr } block, err := s.chain.GetBlock(hash) if err != nil { return nil, response.NewRPCError("Failed to get block", err.Error()) } if v, _ := reqParams.Value(1).GetBoolean(); v { return result.NewBlock(block, s.chain), nil } writer := io.NewBufBinWriter() block.EncodeBinary(writer.BinWriter) return writer.Bytes(), nil } func (s *Server) getBlockHash(reqParams request.Params) (interface{}, *response.Error) { num, err := s.blockHeightFromParam(reqParams.Value(0)) if err != nil { return nil, response.ErrInvalidParams } return s.chain.GetHeaderHash(num), nil } func (s *Server) getVersion(_ request.Params) (interface{}, *response.Error) { port, err := s.coreServer.Port() if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("cannot fetch tcp port: %s", err)) } cfg := s.chain.GetConfig() return &result.Version{ Magic: s.network, TCPPort: port, Nonce: s.coreServer.ID(), UserAgent: s.coreServer.UserAgent, StateRootInHeader: cfg.StateRootInHeader, Protocol: result.Protocol{ AddressVersion: address.NEO3Prefix, Network: cfg.Magic, MillisecondsPerBlock: cfg.SecondsPerBlock * 1000, MaxTraceableBlocks: cfg.MaxTraceableBlocks, MaxValidUntilBlockIncrement: cfg.MaxValidUntilBlockIncrement, MaxTransactionsPerBlock: cfg.MaxTransactionsPerBlock, MemoryPoolMaxTransactions: cfg.MemPoolSize, ValidatorsCount: byte(cfg.GetNumOfCNs(s.chain.BlockHeight())), InitialGasDistribution: cfg.InitialGASSupply, StateRootInHeader: cfg.StateRootInHeader, }, }, nil } func (s *Server) getPeers(_ request.Params) (interface{}, *response.Error) { peers := result.NewGetPeers() peers.AddUnconnected(s.coreServer.UnconnectedPeers()) peers.AddConnected(s.coreServer.ConnectedPeers()) peers.AddBad(s.coreServer.BadPeers()) return peers, nil } func (s *Server) getRawMempool(reqParams request.Params) (interface{}, *response.Error) { verbose, _ := reqParams.Value(0).GetBoolean() mp := s.chain.GetMemPool() hashList := make([]util.Uint256, 0) for _, item := range mp.GetVerifiedTransactions() { hashList = append(hashList, item.Hash()) } if !verbose { return hashList, nil } return result.RawMempool{ Height: s.chain.BlockHeight(), Verified: hashList, Unverified: []util.Uint256{}, // avoid `null` result }, nil } func (s *Server) validateAddress(reqParams request.Params) (interface{}, *response.Error) { param, err := reqParams.Value(0).GetString() if err != nil { return nil, response.ErrInvalidParams } return result.ValidateAddress{ Address: reqParams.Value(0), IsValid: validateAddress(param), }, nil } // calculateNetworkFee calculates network fee for the transaction. func (s *Server) calculateNetworkFee(reqParams request.Params) (interface{}, *response.Error) { if len(reqParams) < 1 { return 0, response.ErrInvalidParams } byteTx, err := reqParams[0].GetBytesBase64() if err != nil { return 0, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } tx, err := transaction.NewTransactionFromBytes(byteTx) if err != nil { return 0, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } hashablePart, err := tx.EncodeHashableFields() if err != nil { return 0, response.WrapErrorWithData(response.ErrInvalidParams, fmt.Sprintf("failed to compute tx size: %s", err)) } size := len(hashablePart) + io.GetVarSize(len(tx.Signers)) var ( ef int64 netFee int64 ) for i, signer := range tx.Signers { var verificationScript []byte for _, w := range tx.Scripts { if w.VerificationScript != nil && hash.Hash160(w.VerificationScript).Equals(signer.Account) { // then it's a standard sig/multisig witness verificationScript = w.VerificationScript break } } if verificationScript == nil { // then it still might be a contract-based verification gasConsumed, err := s.chain.VerifyWitness(signer.Account, tx, &tx.Scripts[i], int64(s.config.MaxGasInvoke)) if err != nil { return 0, response.NewRPCError("Invalid signature", fmt.Sprintf("contract verification for signer #%d failed: %s", i, err)) } netFee += gasConsumed size += io.GetVarSize([]byte{}) + // verification script is empty (contract-based witness) io.GetVarSize(tx.Scripts[i].InvocationScript) // invocation script might not be empty (args for `verify`) continue } if ef == 0 { ef = s.chain.GetBaseExecFee() } fee, sizeDelta := fee.Calculate(ef, verificationScript) netFee += fee size += sizeDelta } fee := s.chain.FeePerByte() netFee += int64(size) * fee return result.NetworkFee{Value: netFee}, nil } // getApplicationLog returns the contract log based on the specified txid or blockid. func (s *Server) getApplicationLog(reqParams request.Params) (interface{}, *response.Error) { hash, err := reqParams.Value(0).GetUint256() if err != nil { return nil, response.ErrInvalidParams } trig := trigger.All if len(reqParams) > 1 { trigString, err := reqParams.Value(1).GetString() if err != nil { return nil, response.ErrInvalidParams } trig, err = trigger.FromString(trigString) if err != nil { return nil, response.ErrInvalidParams } } appExecResults, err := s.chain.GetAppExecResults(hash, trigger.All) if err != nil { return nil, response.WrapErrorWithData(response.ErrUnknownScriptContainer, fmt.Sprintf("failed to locate application log: %s", err)) } return result.NewApplicationLog(hash, appExecResults, trig), nil } func (s *Server) getNEP11Tokens(h util.Uint160, acc util.Uint160, bw *io.BufBinWriter) ([]stackitem.Item, error) { item, finalize, err := s.invokeReadOnly(bw, h, "tokensOf", acc) if err != nil { return nil, err } defer finalize() if (item.Type() == stackitem.InteropT) && iterator.IsIterator(item) { vals, _ := iterator.Values(item, s.config.MaxNEP11Tokens) return vals, nil } return nil, fmt.Errorf("invalid `tokensOf` result type %s", item.String()) } func (s *Server) getNEP11Balances(ps request.Params) (interface{}, *response.Error) { u, err := ps.Value(0).GetUint160FromAddressOrHex() if err != nil { return nil, response.ErrInvalidParams } bs := &result.NEP11Balances{ Address: address.Uint160ToString(u), Balances: []result.NEP11AssetBalance{}, } lastUpdated, err := s.chain.GetTokenLastUpdated(u) if err != nil { return nil, response.NewRPCError("Failed to get NEP-11 last updated block", err.Error()) } var count int stateSyncPoint := lastUpdated[math.MinInt32] bw := io.NewBufBinWriter() contract_loop: for _, h := range s.chain.GetNEP11Contracts() { toks, err := s.getNEP11Tokens(h, u, bw) if err != nil { continue } if len(toks) == 0 { continue } cs := s.chain.GetContractState(h) if cs == nil { continue } isDivisible := (cs.Manifest.ABI.GetMethod("balanceOf", 2) != nil) lub, ok := lastUpdated[cs.ID] if !ok { cfg := s.chain.GetConfig() if !cfg.P2PStateExchangeExtensions && cfg.RemoveUntraceableBlocks { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get LastUpdatedBlock for balance of %s token: internal database inconsistency", cs.Hash.StringLE())) } lub = stateSyncPoint } bs.Balances = append(bs.Balances, result.NEP11AssetBalance{ Asset: h, Tokens: make([]result.NEP11TokenBalance, 0, len(toks)), }) curAsset := &bs.Balances[len(bs.Balances)-1] for i := range toks { id, err := toks[i].TryBytes() if err != nil || len(id) > storage.MaxStorageKeyLen { continue } var amount = "1" if isDivisible { balance, err := s.getTokenBalance(h, u, id, bw) if err != nil { continue } if balance.Sign() == 0 { continue } amount = balance.String() } count++ curAsset.Tokens = append(curAsset.Tokens, result.NEP11TokenBalance{ ID: hex.EncodeToString(id), Amount: amount, LastUpdated: lub, }) if count >= s.config.MaxNEP11Tokens { break contract_loop } } } return bs, nil } func (s *Server) invokeNEP11Properties(h util.Uint160, id []byte, bw *io.BufBinWriter) ([]stackitem.MapElement, error) { item, finalize, err := s.invokeReadOnly(bw, h, "properties", id) if err != nil { return nil, err } defer finalize() if item.Type() != stackitem.MapT { return nil, fmt.Errorf("invalid `properties` result type %s", item.String()) } return item.Value().([]stackitem.MapElement), nil } func (s *Server) getNEP11Properties(ps request.Params) (interface{}, *response.Error) { asset, err := ps.Value(0).GetUint160FromAddressOrHex() if err != nil { return nil, response.ErrInvalidParams } token, err := ps.Value(1).GetBytesHex() if err != nil { return nil, response.ErrInvalidParams } props, err := s.invokeNEP11Properties(asset, token, nil) if err != nil { return nil, response.NewRPCError("Failed to get NEP-11 properties", err.Error()) } res := make(map[string]interface{}) for _, kv := range props { key, err := kv.Key.TryBytes() if err != nil { continue } var val interface{} if result.KnownNEP11Properties[string(key)] || kv.Value.Type() != stackitem.AnyT { v, err := kv.Value.TryBytes() if err != nil { continue } if result.KnownNEP11Properties[string(key)] { val = string(v) } else { val = v } } res[string(key)] = val } return res, nil } func (s *Server) getNEP17Balances(ps request.Params) (interface{}, *response.Error) { u, err := ps.Value(0).GetUint160FromAddressOrHex() if err != nil { return nil, response.ErrInvalidParams } bs := &result.NEP17Balances{ Address: address.Uint160ToString(u), Balances: []result.NEP17Balance{}, } lastUpdated, err := s.chain.GetTokenLastUpdated(u) if err != nil { return nil, response.NewRPCError("Failed to get NEP-17 last updated block", err.Error()) } stateSyncPoint := lastUpdated[math.MinInt32] bw := io.NewBufBinWriter() for _, h := range s.chain.GetNEP17Contracts() { balance, err := s.getTokenBalance(h, u, nil, bw) if err != nil { continue } if balance.Sign() == 0 { continue } cs := s.chain.GetContractState(h) if cs == nil { continue } lub, ok := lastUpdated[cs.ID] if !ok { cfg := s.chain.GetConfig() if !cfg.P2PStateExchangeExtensions && cfg.RemoveUntraceableBlocks { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get LastUpdatedBlock for balance of %s token: internal database inconsistency", cs.Hash.StringLE())) } lub = stateSyncPoint } bs.Balances = append(bs.Balances, result.NEP17Balance{ Asset: h, Amount: balance.String(), LastUpdated: lub, }) } return bs, nil } func (s *Server) invokeReadOnly(bw *io.BufBinWriter, h util.Uint160, method string, params ...interface{}) (stackitem.Item, func(), error) { if bw == nil { bw = io.NewBufBinWriter() } else { bw.Reset() } emit.AppCall(bw.BinWriter, h, method, callflag.ReadStates|callflag.AllowCall, params...) if bw.Err != nil { return nil, nil, fmt.Errorf("failed to create `%s` invocation script: %w", method, bw.Err) } script := bw.Bytes() tx := &transaction.Transaction{Script: script} b, err := s.getFakeNextBlock(s.chain.BlockHeight() + 1) if err != nil { return nil, nil, err } ic := s.chain.GetTestVM(trigger.Application, tx, b) ic.VM.GasLimit = core.HeaderVerificationGasLimit ic.VM.LoadScriptWithFlags(script, callflag.All) err = ic.VM.Run() if err != nil { ic.Finalize() return nil, nil, fmt.Errorf("failed to run `%s` for %s: %w", method, h.StringLE(), err) } if ic.VM.Estack().Len() != 1 { ic.Finalize() return nil, nil, fmt.Errorf("invalid `%s` return values count: expected 1, got %d", method, ic.VM.Estack().Len()) } return ic.VM.Estack().Pop().Item(), ic.Finalize, nil } func (s *Server) getTokenBalance(h util.Uint160, acc util.Uint160, id []byte, bw *io.BufBinWriter) (*big.Int, error) { var ( item stackitem.Item finalize func() err error ) if id == nil { // NEP-17 and NEP-11 generic. item, finalize, err = s.invokeReadOnly(bw, h, "balanceOf", acc) } else { // NEP-11 divisible. item, finalize, err = s.invokeReadOnly(bw, h, "balanceOf", acc, id) } if err != nil { return nil, err } finalize() res, err := item.TryInteger() if err != nil { return nil, fmt.Errorf("unexpected `balanceOf` result type: %w", err) } return res, nil } func getTimestampsAndLimit(ps request.Params, index int) (uint64, uint64, int, int, error) { var start, end uint64 var limit, page int limit = maxTransfersLimit pStart, pEnd, pLimit, pPage := ps.Value(index), ps.Value(index+1), ps.Value(index+2), ps.Value(index+3) if pPage != nil { p, err := pPage.GetInt() if err != nil { return 0, 0, 0, 0, err } if p < 0 { return 0, 0, 0, 0, errors.New("can't use negative page") } page = p } if pLimit != nil { l, err := pLimit.GetInt() if err != nil { return 0, 0, 0, 0, err } if l <= 0 { return 0, 0, 0, 0, errors.New("can't use negative or zero limit") } if l > maxTransfersLimit { return 0, 0, 0, 0, errors.New("too big limit requested") } limit = l } if pEnd != nil { val, err := pEnd.GetInt() if err != nil { return 0, 0, 0, 0, err } end = uint64(val) } else { end = uint64(time.Now().Unix() * 1000) } if pStart != nil { val, err := pStart.GetInt() if err != nil { return 0, 0, 0, 0, err } start = uint64(val) } else { start = uint64(time.Now().Add(-time.Hour*24*7).Unix() * 1000) } return start, end, limit, page, nil } func (s *Server) getNEP11Transfers(ps request.Params) (interface{}, *response.Error) { return s.getTokenTransfers(ps, true) } func (s *Server) getNEP17Transfers(ps request.Params) (interface{}, *response.Error) { return s.getTokenTransfers(ps, false) } func (s *Server) getTokenTransfers(ps request.Params, isNEP11 bool) (interface{}, *response.Error) { u, err := ps.Value(0).GetUint160FromAddressOrHex() if err != nil { return nil, response.ErrInvalidParams } start, end, limit, page, err := getTimestampsAndLimit(ps, 1) if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("malformed timestamps/limit: %s", err)) } bs := &tokenTransfers{ Address: address.Uint160ToString(u), Received: []interface{}{}, Sent: []interface{}{}, } cache := make(map[int32]util.Uint160) var resCount, frameCount int // handleTransfer returns items to be added into the received and sent arrays // along with a continue flag and error. var handleTransfer = func(tr *state.NEP17Transfer) (*result.NEP17Transfer, *result.NEP17Transfer, bool, error) { var received, sent *result.NEP17Transfer // Iterating from the newest to the oldest, not yet reached required // time frame, continue looping. if tr.Timestamp > end { return nil, nil, true, nil } // Iterating from the newest to the oldest, moved past required // time frame, stop looping. if tr.Timestamp < start { return nil, nil, false, nil } frameCount++ // Using limits, not yet reached required page. if limit != 0 && page*limit >= frameCount { return nil, nil, true, nil } h, err := s.getHash(tr.Asset, cache) if err != nil { return nil, nil, false, err } transfer := result.NEP17Transfer{ Timestamp: tr.Timestamp, Asset: h, Index: tr.Block, TxHash: tr.Tx, } if tr.Amount.Sign() > 0 { // token was received transfer.Amount = tr.Amount.String() if !tr.From.Equals(util.Uint160{}) { transfer.Address = address.Uint160ToString(tr.From) } received = &result.NEP17Transfer{} *received = transfer // Make a copy, transfer is to be modified below. } else { transfer.Amount = new(big.Int).Neg(&tr.Amount).String() if !tr.To.Equals(util.Uint160{}) { transfer.Address = address.Uint160ToString(tr.To) } sent = &result.NEP17Transfer{} *sent = transfer } resCount++ // Check limits for continue flag. return received, sent, !(limit != 0 && resCount >= limit), nil } if !isNEP11 { err = s.chain.ForEachNEP17Transfer(u, end, func(tr *state.NEP17Transfer) (bool, error) { r, s, res, err := handleTransfer(tr) if err == nil { if r != nil { bs.Received = append(bs.Received, r) } if s != nil { bs.Sent = append(bs.Sent, s) } } return res, err }) } else { err = s.chain.ForEachNEP11Transfer(u, end, func(tr *state.NEP11Transfer) (bool, error) { r, s, res, err := handleTransfer(&tr.NEP17Transfer) if err == nil { id := hex.EncodeToString(tr.ID) if r != nil { bs.Received = append(bs.Received, nep17TransferToNEP11(r, id)) } if s != nil { bs.Sent = append(bs.Sent, nep17TransferToNEP11(s, id)) } } return res, err }) } if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("invalid transfer log: %s", err)) } return bs, nil } // getHash returns the hash of the contract by its ID using cache. func (s *Server) getHash(contractID int32, cache map[int32]util.Uint160) (util.Uint160, error) { if d, ok := cache[contractID]; ok { return d, nil } h, err := s.chain.GetContractScriptHash(contractID) if err != nil { return util.Uint160{}, err } cache[contractID] = h return h, nil } func (s *Server) contractIDFromParam(param *request.Param) (int32, *response.Error) { var result int32 if param == nil { return 0, response.ErrInvalidParams } if scriptHash, err := param.GetUint160FromHex(); err == nil { cs := s.chain.GetContractState(scriptHash) if cs == nil { return 0, response.ErrUnknown } result = cs.ID } else { id, err := param.GetInt() if err != nil { return 0, response.ErrInvalidParams } if err := checkInt32(id); err != nil { return 0, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } result = int32(id) } return result, nil } // getContractScriptHashFromParam returns the contract script hash by hex contract hash, address, id or native contract name. func (s *Server) contractScriptHashFromParam(param *request.Param) (util.Uint160, *response.Error) { var result util.Uint160 if param == nil { return result, response.ErrInvalidParams } nameOrHashOrIndex, err := param.GetString() if err != nil { return result, response.ErrInvalidParams } result, err = param.GetUint160FromAddressOrHex() if err == nil { return result, nil } result, err = s.chain.GetNativeContractScriptHash(nameOrHashOrIndex) if err == nil { return result, nil } id, err := strconv.Atoi(nameOrHashOrIndex) if err != nil { return result, response.NewRPCError("Invalid contract identifier (name/hash/index is expected)", err.Error()) } if err := checkInt32(id); err != nil { return result, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } result, err = s.chain.GetContractScriptHash(int32(id)) if err != nil { return result, response.NewRPCError("Unknown contract", "") } return result, nil } func makeStorageKey(id int32, key []byte) []byte { skey := make([]byte, 4+len(key)) binary.LittleEndian.PutUint32(skey, uint32(id)) copy(skey[4:], key) return skey } var errKeepOnlyLatestState = errors.New("'KeepOnlyLatestState' setting is enabled") func (s *Server) getProof(ps request.Params) (interface{}, *response.Error) { if s.chain.GetConfig().KeepOnlyLatestState { return nil, response.NewInvalidRequestError(fmt.Sprintf("'getproof' is not supported: %s", errKeepOnlyLatestState)) } root, err := ps.Value(0).GetUint256() if err != nil { return nil, response.ErrInvalidParams } sc, err := ps.Value(1).GetUint160FromHex() if err != nil { return nil, response.ErrInvalidParams } key, err := ps.Value(2).GetBytesBase64() if err != nil { return nil, response.ErrInvalidParams } cs, respErr := s.getHistoricalContractState(root, sc) if respErr != nil { return nil, respErr } skey := makeStorageKey(cs.ID, key) proof, err := s.chain.GetStateModule().GetStateProof(root, skey) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get proof: %s", err)) } return &result.ProofWithKey{ Key: skey, Proof: proof, }, nil } func (s *Server) verifyProof(ps request.Params) (interface{}, *response.Error) { if s.chain.GetConfig().KeepOnlyLatestState { return nil, response.NewInvalidRequestError(fmt.Sprintf("'verifyproof' is not supported: %s", errKeepOnlyLatestState)) } root, err := ps.Value(0).GetUint256() if err != nil { return nil, response.ErrInvalidParams } proofStr, err := ps.Value(1).GetString() if err != nil { return nil, response.ErrInvalidParams } var p result.ProofWithKey if err := p.FromString(proofStr); err != nil { return nil, response.ErrInvalidParams } vp := new(result.VerifyProof) val, ok := mpt.VerifyProof(root, p.Key, p.Proof) if ok { vp.Value = val } return vp, nil } func (s *Server) getState(ps request.Params) (interface{}, *response.Error) { root, err := ps.Value(0).GetUint256() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, "invalid stateroot") } if s.chain.GetConfig().KeepOnlyLatestState { curr, err := s.chain.GetStateModule().GetStateRoot(s.chain.BlockHeight()) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get current stateroot: %s", err)) } if !curr.Root.Equals(root) { return nil, response.NewInvalidRequestError(fmt.Sprintf("'getstate' is not supported for old states: %s", errKeepOnlyLatestState)) } } csHash, err := ps.Value(1).GetUint160FromHex() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, "invalid contract hash") } key, err := ps.Value(2).GetBytesBase64() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, "invalid key") } cs, respErr := s.getHistoricalContractState(root, csHash) if respErr != nil { return nil, respErr } sKey := makeStorageKey(cs.ID, key) res, err := s.chain.GetStateModule().GetState(root, sKey) if err != nil { return nil, response.NewRPCError("Failed to get historical item state", err.Error()) } return res, nil } func (s *Server) findStates(ps request.Params) (interface{}, *response.Error) { root, err := ps.Value(0).GetUint256() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, "invalid stateroot") } if s.chain.GetConfig().KeepOnlyLatestState { curr, err := s.chain.GetStateModule().GetStateRoot(s.chain.BlockHeight()) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get current stateroot: %s", err)) } if !curr.Root.Equals(root) { return nil, response.NewInvalidRequestError(fmt.Sprintf("'findstates' is not supported for old states: %s", errKeepOnlyLatestState)) } } csHash, err := ps.Value(1).GetUint160FromHex() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, fmt.Sprintf("invalid contract hash: %s", err)) } prefix, err := ps.Value(2).GetBytesBase64() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, fmt.Sprintf("invalid prefix: %s", err)) } var ( key []byte count = s.config.MaxFindResultItems ) if len(ps) > 3 { key, err = ps.Value(3).GetBytesBase64() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, fmt.Sprintf("invalid key: %s", err)) } if len(key) > 0 { if !bytes.HasPrefix(key, prefix) { return nil, response.WrapErrorWithData(response.ErrInvalidParams, "key doesn't match prefix") } key = key[len(prefix):] } else { // empty ("") key shouldn't exclude item matching prefix from the result key = nil } } if len(ps) > 4 { count, err = ps.Value(4).GetInt() if err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, fmt.Sprintf("invalid count: %s", err)) } if count > s.config.MaxFindResultItems { count = s.config.MaxFindResultItems } } cs, respErr := s.getHistoricalContractState(root, csHash) if respErr != nil { return nil, respErr } pKey := makeStorageKey(cs.ID, prefix) kvs, err := s.chain.GetStateModule().FindStates(root, pKey, key, count+1) // +1 to define result truncation if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to find historical items: %s", err)) } res := result.FindStates{} if len(kvs) == count+1 { res.Truncated = true kvs = kvs[:len(kvs)-1] } if len(kvs) > 0 { proof, err := s.chain.GetStateModule().GetStateProof(root, kvs[0].Key) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get first proof: %s", err)) } res.FirstProof = &result.ProofWithKey{ Key: kvs[0].Key, Proof: proof, } } if len(kvs) > 1 { proof, err := s.chain.GetStateModule().GetStateProof(root, kvs[len(kvs)-1].Key) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to get last proof: %s", err)) } res.LastProof = &result.ProofWithKey{ Key: kvs[len(kvs)-1].Key, Proof: proof, } } res.Results = make([]result.KeyValue, len(kvs)) for i, kv := range kvs { res.Results[i] = result.KeyValue{ Key: kv.Key[4:], // cut contract ID as it is done in C# Value: kv.Value, } } return res, nil } func (s *Server) getHistoricalContractState(root util.Uint256, csHash util.Uint160) (*state.Contract, *response.Error) { csKey := makeStorageKey(native.ManagementContractID, native.MakeContractKey(csHash)) csBytes, err := s.chain.GetStateModule().GetState(root, csKey) if err != nil { return nil, response.NewRPCError("Failed to get historical contract state", err.Error()) } contract := new(state.Contract) err = stackitem.DeserializeConvertible(csBytes, contract) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to deserialize historical contract state: %s", err)) } return contract, nil } func (s *Server) getStateHeight(_ request.Params) (interface{}, *response.Error) { var height = s.chain.BlockHeight() var stateHeight = s.chain.GetStateModule().CurrentValidatedHeight() if s.chain.GetConfig().StateRootInHeader { stateHeight = height - 1 } return &result.StateHeight{ Local: height, Validated: stateHeight, }, nil } func (s *Server) getStateRoot(ps request.Params) (interface{}, *response.Error) { p := ps.Value(0) if p == nil { return nil, response.NewInvalidParamsError("missing stateroot identifier") } var rt *state.MPTRoot var h util.Uint256 height, err := p.GetIntStrict() if err == nil { if err := checkUint32(height); err != nil { return nil, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } rt, err = s.chain.GetStateModule().GetStateRoot(uint32(height)) } else if h, err = p.GetUint256(); err == nil { var hdr *block.Header hdr, err = s.chain.GetHeader(h) if err == nil { rt, err = s.chain.GetStateModule().GetStateRoot(hdr.Index) } } if err != nil { return nil, response.ErrUnknownStateRoot } return rt, nil } func (s *Server) getStorage(ps request.Params) (interface{}, *response.Error) { id, rErr := s.contractIDFromParam(ps.Value(0)) if rErr == response.ErrUnknown { return nil, nil } if rErr != nil { return nil, rErr } key, err := ps.Value(1).GetBytesBase64() if err != nil { return nil, response.ErrInvalidParams } item := s.chain.GetStorageItem(id, key) if item == nil { return "", nil } return []byte(item), nil } func (s *Server) getrawtransaction(reqParams request.Params) (interface{}, *response.Error) { txHash, err := reqParams.Value(0).GetUint256() if err != nil { return nil, response.ErrInvalidParams } tx, height, err := s.chain.GetTransaction(txHash) if err != nil { return nil, response.ErrUnknownTransaction } if v, _ := reqParams.Value(1).GetBoolean(); v { if height == math.MaxUint32 { return result.NewTransactionOutputRaw(tx, nil, nil, s.chain), nil } _header := s.chain.GetHeaderHash(int(height)) header, err := s.chain.GetHeader(_header) if err != nil { return nil, response.NewRPCError("Failed to get header for the transaction", err.Error()) } aers, err := s.chain.GetAppExecResults(txHash, trigger.Application) if err != nil { return nil, response.NewRPCError("Failed to get application log for the transaction", err.Error()) } if len(aers) == 0 { return nil, response.NewRPCError("Inconsistent application log", "application log for the transaction is empty") } return result.NewTransactionOutputRaw(tx, header, &aers[0], s.chain), nil } return tx.Bytes(), nil } func (s *Server) getTransactionHeight(ps request.Params) (interface{}, *response.Error) { h, err := ps.Value(0).GetUint256() if err != nil { return nil, response.ErrInvalidParams } _, height, err := s.chain.GetTransaction(h) if err != nil || height == math.MaxUint32 { return nil, response.ErrUnknownTransaction } return height, nil } // getContractState returns contract state (contract information, according to the contract script hash, // contract id or native contract name). func (s *Server) getContractState(reqParams request.Params) (interface{}, *response.Error) { scriptHash, err := s.contractScriptHashFromParam(reqParams.Value(0)) if err != nil { return nil, err } cs := s.chain.GetContractState(scriptHash) if cs == nil { return nil, response.NewRPCError("Unknown contract", "") } return cs, nil } func (s *Server) getNativeContracts(_ request.Params) (interface{}, *response.Error) { return s.chain.GetNatives(), nil } // getBlockSysFee returns the system fees of the block, based on the specified index. func (s *Server) getBlockSysFee(reqParams request.Params) (interface{}, *response.Error) { num, err := s.blockHeightFromParam(reqParams.Value(0)) if err != nil { return 0, response.NewRPCError("Invalid height", "invalid block identifier") } headerHash := s.chain.GetHeaderHash(num) block, errBlock := s.chain.GetBlock(headerHash) if errBlock != nil { return 0, response.ErrUnknownBlock } var blockSysFee int64 for _, tx := range block.Transactions { blockSysFee += tx.SystemFee } return blockSysFee, nil } // getBlockHeader returns the corresponding block header information according to the specified script hash. func (s *Server) getBlockHeader(reqParams request.Params) (interface{}, *response.Error) { param := reqParams.Value(0) hash, respErr := s.blockHashFromParam(param) if respErr != nil { return nil, respErr } verbose, _ := reqParams.Value(1).GetBoolean() h, err := s.chain.GetHeader(hash) if err != nil { return nil, response.ErrUnknownHeader } if verbose { return result.NewHeader(h, s.chain), nil } buf := io.NewBufBinWriter() h.EncodeBinary(buf.BinWriter) if buf.Err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("encoding error: %s", buf.Err)) } return buf.Bytes(), nil } // getUnclaimedGas returns unclaimed GAS amount of the specified address. func (s *Server) getUnclaimedGas(ps request.Params) (interface{}, *response.Error) { u, err := ps.Value(0).GetUint160FromAddressOrHex() if err != nil { return nil, response.ErrInvalidParams } neo, _ := s.chain.GetGoverningTokenBalance(u) if neo.Sign() == 0 { return result.UnclaimedGas{ Address: u, }, nil } gas, err := s.chain.CalculateClaimable(u, s.chain.BlockHeight()+1) // +1 as in C#, for the next block. if err != nil { return nil, response.NewRPCError("Can't calculate claimable", err.Error()) } return result.UnclaimedGas{ Address: u, Unclaimed: *gas, }, nil } // getNextBlockValidators returns validators for the next block with voting status. func (s *Server) getNextBlockValidators(_ request.Params) (interface{}, *response.Error) { var validators keys.PublicKeys validators, err := s.chain.GetNextBlockValidators() if err != nil { return nil, response.NewRPCError("Can't get next block validators", err.Error()) } enrollments, err := s.chain.GetEnrollments() if err != nil { return nil, response.NewRPCError("Can't get enrollments", err.Error()) } var res = make([]result.Validator, 0) for _, v := range enrollments { res = append(res, result.Validator{ PublicKey: *v.Key, Votes: v.Votes.Int64(), Active: validators.Contains(v.Key), }) } return res, nil } // getCommittee returns the current list of NEO committee members. func (s *Server) getCommittee(_ request.Params) (interface{}, *response.Error) { keys, err := s.chain.GetCommittee() if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("can't get committee members: %s", err)) } return keys, nil } // invokeFunction implements the `invokeFunction` RPC call. func (s *Server) invokeFunction(reqParams request.Params) (interface{}, *response.Error) { tx, verbose, respErr := s.getInvokeFunctionParams(reqParams) if respErr != nil { return nil, respErr } return s.runScriptInVM(trigger.Application, tx.Script, util.Uint160{}, tx, nil, verbose) } // invokeFunctionHistoric implements the `invokeFunctionHistoric` RPC call. func (s *Server) invokeFunctionHistoric(reqParams request.Params) (interface{}, *response.Error) { b, respErr := s.getHistoricParams(reqParams) if respErr != nil { return nil, respErr } if len(reqParams) < 2 { return nil, response.ErrInvalidParams } tx, verbose, respErr := s.getInvokeFunctionParams(reqParams[1:]) if respErr != nil { return nil, respErr } return s.runScriptInVM(trigger.Application, tx.Script, util.Uint160{}, tx, b, verbose) } func (s *Server) getInvokeFunctionParams(reqParams request.Params) (*transaction.Transaction, bool, *response.Error) { if len(reqParams) < 2 { return nil, false, response.ErrInvalidParams } scriptHash, responseErr := s.contractScriptHashFromParam(reqParams.Value(0)) if responseErr != nil { return nil, false, responseErr } method, err := reqParams[1].GetString() if err != nil { return nil, false, response.ErrInvalidParams } var params *request.Param if len(reqParams) > 2 { params = &reqParams[2] } tx := &transaction.Transaction{} if len(reqParams) > 3 { signers, _, err := reqParams[3].GetSignersWithWitnesses() if err != nil { return nil, false, response.ErrInvalidParams } tx.Signers = signers } var verbose bool if len(reqParams) > 4 { verbose, err = reqParams[4].GetBoolean() if err != nil { return nil, false, response.ErrInvalidParams } } if len(tx.Signers) == 0 { tx.Signers = []transaction.Signer{{Account: util.Uint160{}, Scopes: transaction.None}} } script, err := request.CreateFunctionInvocationScript(scriptHash, method, params) if err != nil { return nil, false, response.NewInternalServerError(fmt.Sprintf("can't create invocation script: %s", err)) } tx.Script = script return tx, verbose, nil } // invokescript implements the `invokescript` RPC call. func (s *Server) invokescript(reqParams request.Params) (interface{}, *response.Error) { tx, verbose, respErr := s.getInvokeScriptParams(reqParams) if respErr != nil { return nil, respErr } return s.runScriptInVM(trigger.Application, tx.Script, util.Uint160{}, tx, nil, verbose) } // invokescripthistoric implements the `invokescripthistoric` RPC call. func (s *Server) invokescripthistoric(reqParams request.Params) (interface{}, *response.Error) { b, respErr := s.getHistoricParams(reqParams) if respErr != nil { return nil, respErr } if len(reqParams) < 2 { return nil, response.ErrInvalidParams } tx, verbose, respErr := s.getInvokeScriptParams(reqParams[1:]) if respErr != nil { return nil, respErr } return s.runScriptInVM(trigger.Application, tx.Script, util.Uint160{}, tx, b, verbose) } func (s *Server) getInvokeScriptParams(reqParams request.Params) (*transaction.Transaction, bool, *response.Error) { script, err := reqParams.Value(0).GetBytesBase64() if err != nil { return nil, false, response.ErrInvalidParams } tx := &transaction.Transaction{} if len(reqParams) > 1 { signers, witnesses, err := reqParams[1].GetSignersWithWitnesses() if err != nil { return nil, false, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } tx.Signers = signers tx.Scripts = witnesses } var verbose bool if len(reqParams) > 2 { verbose, err = reqParams[2].GetBoolean() if err != nil { return nil, false, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } } if len(tx.Signers) == 0 { tx.Signers = []transaction.Signer{{Account: util.Uint160{}, Scopes: transaction.None}} } tx.Script = script return tx, verbose, nil } // invokeContractVerify implements the `invokecontractverify` RPC call. func (s *Server) invokeContractVerify(reqParams request.Params) (interface{}, *response.Error) { scriptHash, tx, invocationScript, respErr := s.getInvokeContractVerifyParams(reqParams) if respErr != nil { return nil, respErr } return s.runScriptInVM(trigger.Verification, invocationScript, scriptHash, tx, nil, false) } // invokeContractVerifyHistoric implements the `invokecontractverifyhistoric` RPC call. func (s *Server) invokeContractVerifyHistoric(reqParams request.Params) (interface{}, *response.Error) { b, respErr := s.getHistoricParams(reqParams) if respErr != nil { return nil, respErr } if len(reqParams) < 2 { return nil, response.ErrInvalidParams } scriptHash, tx, invocationScript, respErr := s.getInvokeContractVerifyParams(reqParams[1:]) if respErr != nil { return nil, respErr } return s.runScriptInVM(trigger.Verification, invocationScript, scriptHash, tx, b, false) } func (s *Server) getInvokeContractVerifyParams(reqParams request.Params) (util.Uint160, *transaction.Transaction, []byte, *response.Error) { scriptHash, responseErr := s.contractScriptHashFromParam(reqParams.Value(0)) if responseErr != nil { return util.Uint160{}, nil, nil, responseErr } bw := io.NewBufBinWriter() if len(reqParams) > 1 { args, err := reqParams[1].GetArray() // second `invokecontractverify` parameter is an array of arguments for `verify` method if err != nil { return util.Uint160{}, nil, nil, response.WrapErrorWithData(response.ErrInvalidParams, err.Error()) } if len(args) > 0 { err := request.ExpandArrayIntoScript(bw.BinWriter, args) if err != nil { return util.Uint160{}, nil, nil, response.NewInternalServerError(fmt.Sprintf("can't create witness invocation script: %s", err)) } } } invocationScript := bw.Bytes() tx := &transaction.Transaction{Script: []byte{byte(opcode.RET)}} // need something in script if len(reqParams) > 2 { signers, witnesses, err := reqParams[2].GetSignersWithWitnesses() if err != nil { return util.Uint160{}, nil, nil, response.ErrInvalidParams } tx.Signers = signers tx.Scripts = witnesses } else { // fill the only known signer - the contract with `verify` method tx.Signers = []transaction.Signer{{Account: scriptHash}} tx.Scripts = []transaction.Witness{{InvocationScript: invocationScript, VerificationScript: []byte{}}} } return scriptHash, tx, invocationScript, nil } // getHistoricParams checks that historic calls are supported and returns fake block // with the specified index to perform the historic call. It also checks that // specified stateroot is stored at the specified height for further request // handling consistency. func (s *Server) getHistoricParams(reqParams request.Params) (*block.Block, *response.Error) { if s.chain.GetConfig().KeepOnlyLatestState { return nil, response.NewInvalidRequestError(fmt.Sprintf("only latest state is supported: %s", errKeepOnlyLatestState)) } if len(reqParams) < 1 { return nil, response.ErrInvalidParams } height, respErr := s.blockHeightFromParam(reqParams.Value(0)) if respErr != nil { hash, err := reqParams.Value(0).GetUint256() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("invalid block hash or index or stateroot hash: %s", err)) } b, err := s.chain.GetBlock(hash) if err != nil { stateH, err := s.chain.GetStateModule().GetLatestStateHeight(hash) if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("unknown block or stateroot: %s", err)) } height = int(stateH) } else { height = int(b.Index) } } b, err := s.getFakeNextBlock(uint32(height)) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("can't create fake block for height %d: %s", height, err)) } return b, nil } func (s *Server) getFakeNextBlock(nextBlockHeight uint32) (*block.Block, error) { // When transferring funds, script execution does no auto GAS claim, // because it depends on persisting tx height. // This is why we provide block here. b := block.New(s.stateRootEnabled) b.Index = nextBlockHeight hdr, err := s.chain.GetHeader(s.chain.GetHeaderHash(int(nextBlockHeight - 1))) if err != nil { return nil, err } b.Timestamp = hdr.Timestamp + uint64(s.chain.GetConfig().SecondsPerBlock*int(time.Second/time.Millisecond)) return b, nil } // runScriptInVM runs the given script in a new test VM and returns the invocation // result. The script is either a simple script in case of `application` trigger, // witness invocation script in case of `verification` trigger (it pushes `verify` // arguments on stack before verification). In case of contract verification // contractScriptHash should be specified. func (s *Server) runScriptInVM(t trigger.Type, script []byte, contractScriptHash util.Uint160, tx *transaction.Transaction, b *block.Block, verbose bool) (*result.Invoke, *response.Error) { var ( err error ic *interop.Context ) if b == nil { b, err = s.getFakeNextBlock(s.chain.BlockHeight() + 1) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("can't create fake block: %s", err)) } ic = s.chain.GetTestVM(t, tx, b) } else { ic, err = s.chain.GetTestHistoricVM(t, tx, b) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("failed to create historic VM: %s", err)) } } if verbose { ic.VM.EnableInvocationTree() } ic.VM.GasLimit = int64(s.config.MaxGasInvoke) if t == trigger.Verification { // We need this special case because witnesses verification is not the simple System.Contract.Call, // and we need to define exactly the amount of gas consumed for a contract witness verification. gasPolicy := s.chain.GetMaxVerificationGAS() if ic.VM.GasLimit > gasPolicy { ic.VM.GasLimit = gasPolicy } err = s.chain.InitVerificationContext(ic, contractScriptHash, &transaction.Witness{InvocationScript: script, VerificationScript: []byte{}}) if err != nil { return nil, response.NewInternalServerError(fmt.Sprintf("can't prepare verification VM: %s", err)) } } else { ic.VM.LoadScriptWithFlags(script, callflag.All) } err = ic.VM.Run() var faultException string if err != nil { faultException = err.Error() } return result.NewInvoke(ic, script, faultException, s.config.MaxIteratorResultItems), nil } // submitBlock broadcasts a raw block over the NEO network. func (s *Server) submitBlock(reqParams request.Params) (interface{}, *response.Error) { blockBytes, err := reqParams.Value(0).GetBytesBase64() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("missing parameter or not a base64: %s", err)) } b := block.New(s.stateRootEnabled) r := io.NewBinReaderFromBuf(blockBytes) b.DecodeBinary(r) if r.Err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("can't decode block: %s", r.Err)) } err = s.chain.AddBlock(b) if err != nil { switch { case errors.Is(err, core.ErrInvalidBlockIndex) || errors.Is(err, core.ErrAlreadyExists): return nil, response.WrapErrorWithData(response.ErrAlreadyExists, err.Error()) default: return nil, response.WrapErrorWithData(response.ErrValidationFailed, err.Error()) } } return &result.RelayResult{ Hash: b.Hash(), }, nil } // submitNotaryRequest broadcasts P2PNotaryRequest over the NEO network. func (s *Server) submitNotaryRequest(ps request.Params) (interface{}, *response.Error) { if !s.chain.P2PSigExtensionsEnabled() { return nil, response.NewRPCError("P2PSignatureExtensions are disabled", "") } bytePayload, err := ps.Value(0).GetBytesBase64() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("not a base64: %s", err)) } r, err := payload.NewP2PNotaryRequestFromBytes(bytePayload) if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("can't decode notary payload: %s", err)) } return getRelayResult(s.coreServer.RelayP2PNotaryRequest(r), r.FallbackTransaction.Hash()) } // getRelayResult returns successful relay result or an error. func getRelayResult(err error, hash util.Uint256) (interface{}, *response.Error) { switch { case err == nil: return result.RelayResult{ Hash: hash, }, nil case errors.Is(err, core.ErrAlreadyExists): return nil, response.WrapErrorWithData(response.ErrAlreadyExists, err.Error()) case errors.Is(err, core.ErrOOM): return nil, response.WrapErrorWithData(response.ErrOutOfMemory, err.Error()) case errors.Is(err, core.ErrPolicy): return nil, response.WrapErrorWithData(response.ErrPolicyFail, err.Error()) default: return nil, response.WrapErrorWithData(response.ErrValidationFailed, err.Error()) } } func (s *Server) submitOracleResponse(ps request.Params) (interface{}, *response.Error) { if s.oracle == nil { return nil, response.NewRPCError("Oracle is not enabled", "") } var pub *keys.PublicKey pubBytes, err := ps.Value(0).GetBytesBase64() if err == nil { pub, err = keys.NewPublicKeyFromBytes(pubBytes, elliptic.P256()) } if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("public key is missing: %s", err)) } reqID, err := ps.Value(1).GetInt() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("request ID is missing: %s", err)) } txSig, err := ps.Value(2).GetBytesBase64() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("tx signature is missing: %s", err)) } msgSig, err := ps.Value(3).GetBytesBase64() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("msg signature is missing: %s", err)) } data := broadcaster.GetMessage(pubBytes, uint64(reqID), txSig) if !pub.Verify(msgSig, hash.Sha256(data).BytesBE()) { return nil, response.NewRPCError("Invalid request signature", "") } s.oracle.AddResponse(pub, uint64(reqID), txSig) return json.RawMessage([]byte("{}")), nil } func (s *Server) sendrawtransaction(reqParams request.Params) (interface{}, *response.Error) { if len(reqParams) < 1 { return nil, response.NewInvalidParamsError("not enough parameters") } byteTx, err := reqParams[0].GetBytesBase64() if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("not a base64: %s", err)) } tx, err := transaction.NewTransactionFromBytes(byteTx) if err != nil { return nil, response.NewInvalidParamsError(fmt.Sprintf("can't decode transaction: %s", err)) } return getRelayResult(s.coreServer.RelayTxn(tx), tx.Hash()) } // subscribe handles subscription requests from websocket clients. func (s *Server) subscribe(reqParams request.Params, sub *subscriber) (interface{}, *response.Error) { streamName, err := reqParams.Value(0).GetString() if err != nil { return nil, response.ErrInvalidParams } event, err := response.GetEventIDFromString(streamName) if err != nil || event == response.MissedEventID { return nil, response.ErrInvalidParams } if event == response.NotaryRequestEventID && !s.chain.P2PSigExtensionsEnabled() { return nil, response.WrapErrorWithData(response.ErrInvalidParams, "P2PSigExtensions are disabled") } // Optional filter. var filter interface{} if p := reqParams.Value(1); p != nil { param := *p jd := json.NewDecoder(bytes.NewReader(param.RawMessage)) jd.DisallowUnknownFields() switch event { case response.BlockEventID: flt := new(request.BlockFilter) err = jd.Decode(flt) filter = *flt case response.TransactionEventID, response.NotaryRequestEventID: flt := new(request.TxFilter) err = jd.Decode(flt) filter = *flt case response.NotificationEventID: flt := new(request.NotificationFilter) err = jd.Decode(flt) filter = *flt case response.ExecutionEventID: flt := new(request.ExecutionFilter) err = jd.Decode(flt) if err == nil && (flt.State == "HALT" || flt.State == "FAULT") { filter = *flt } else if err == nil { err = errors.New("invalid state") } } if err != nil { return nil, response.ErrInvalidParams } } s.subsLock.Lock() defer s.subsLock.Unlock() select { case <-s.shutdown: return nil, response.NewInternalServerError("server is shutting down") default: } var id int for ; id < len(sub.feeds); id++ { if sub.feeds[id].event == response.InvalidEventID { break } } if id == len(sub.feeds) { return nil, response.NewInternalServerError("maximum number of subscriptions is reached") } sub.feeds[id].event = event sub.feeds[id].filter = filter s.subscribeToChannel(event) return strconv.FormatInt(int64(id), 10), nil } // subscribeToChannel subscribes RPC server to appropriate chain events if // it's not yet subscribed for them. It's supposed to be called with s.subsLock // taken by the caller. func (s *Server) subscribeToChannel(event response.EventID) { switch event { case response.BlockEventID: if s.blockSubs == 0 { s.chain.SubscribeForBlocks(s.blockCh) } s.blockSubs++ case response.TransactionEventID: if s.transactionSubs == 0 { s.chain.SubscribeForTransactions(s.transactionCh) } s.transactionSubs++ case response.NotificationEventID: if s.notificationSubs == 0 { s.chain.SubscribeForNotifications(s.notificationCh) } s.notificationSubs++ case response.ExecutionEventID: if s.executionSubs == 0 { s.chain.SubscribeForExecutions(s.executionCh) } s.executionSubs++ case response.NotaryRequestEventID: if s.notaryRequestSubs == 0 { s.coreServer.SubscribeForNotaryRequests(s.notaryRequestCh) } s.notaryRequestSubs++ } } // unsubscribe handles unsubscription requests from websocket clients. func (s *Server) unsubscribe(reqParams request.Params, sub *subscriber) (interface{}, *response.Error) { id, err := reqParams.Value(0).GetInt() if err != nil || id < 0 { return nil, response.ErrInvalidParams } s.subsLock.Lock() defer s.subsLock.Unlock() if len(sub.feeds) <= id || sub.feeds[id].event == response.InvalidEventID { return nil, response.ErrInvalidParams } event := sub.feeds[id].event sub.feeds[id].event = response.InvalidEventID sub.feeds[id].filter = nil s.unsubscribeFromChannel(event) return true, nil } // unsubscribeFromChannel unsubscribes RPC server from appropriate chain events // if there are no other subscribers for it. It's supposed to be called with // s.subsLock taken by the caller. func (s *Server) unsubscribeFromChannel(event response.EventID) { switch event { case response.BlockEventID: s.blockSubs-- if s.blockSubs == 0 { s.chain.UnsubscribeFromBlocks(s.blockCh) } case response.TransactionEventID: s.transactionSubs-- if s.transactionSubs == 0 { s.chain.UnsubscribeFromTransactions(s.transactionCh) } case response.NotificationEventID: s.notificationSubs-- if s.notificationSubs == 0 { s.chain.UnsubscribeFromNotifications(s.notificationCh) } case response.ExecutionEventID: s.executionSubs-- if s.executionSubs == 0 { s.chain.UnsubscribeFromExecutions(s.executionCh) } case response.NotaryRequestEventID: s.notaryRequestSubs-- if s.notaryRequestSubs == 0 { s.coreServer.UnsubscribeFromNotaryRequests(s.notaryRequestCh) } } } func (s *Server) handleSubEvents() { b, err := json.Marshal(response.Notification{ JSONRPC: request.JSONRPCVersion, Event: response.MissedEventID, Payload: make([]interface{}, 0), }) if err != nil { s.log.Error("fatal: failed to marshal overflow event", zap.Error(err)) return } overflowMsg, err := websocket.NewPreparedMessage(websocket.TextMessage, b) if err != nil { s.log.Error("fatal: failed to prepare overflow message", zap.Error(err)) return } chloop: for { var resp = response.Notification{ JSONRPC: request.JSONRPCVersion, Payload: make([]interface{}, 1), } var msg *websocket.PreparedMessage select { case <-s.shutdown: break chloop case b := <-s.blockCh: resp.Event = response.BlockEventID resp.Payload[0] = b case execution := <-s.executionCh: resp.Event = response.ExecutionEventID resp.Payload[0] = execution case notification := <-s.notificationCh: resp.Event = response.NotificationEventID resp.Payload[0] = notification case tx := <-s.transactionCh: resp.Event = response.TransactionEventID resp.Payload[0] = tx case e := <-s.notaryRequestCh: resp.Event = response.NotaryRequestEventID resp.Payload[0] = &subscriptions.NotaryRequestEvent{ Type: e.Type, NotaryRequest: e.Data.(*payload.P2PNotaryRequest), } } s.subsLock.RLock() subloop: for sub := range s.subscribers { if sub.overflown.Load() { continue } for i := range sub.feeds { if sub.feeds[i].Matches(&resp) { if msg == nil { b, err = json.Marshal(resp) if err != nil { s.log.Error("failed to marshal notification", zap.Error(err), zap.String("type", resp.Event.String())) break subloop } msg, err = websocket.NewPreparedMessage(websocket.TextMessage, b) if err != nil { s.log.Error("failed to prepare notification message", zap.Error(err), zap.String("type", resp.Event.String())) break subloop } } select { case sub.writer <- msg: default: sub.overflown.Store(true) // MissedEvent is to be delivered eventually. go func(sub *subscriber) { sub.writer <- overflowMsg sub.overflown.Store(false) }(sub) } // The message is sent only once per subscriber. break } } } s.subsLock.RUnlock() } // It's important to do it with lock held because no subscription routine // should be running concurrently to this one. And even if one is to run // after unlock, it'll see closed s.shutdown and won't subscribe. s.subsLock.Lock() // There might be no subscription in reality, but it's not a problem as // core.Blockchain allows unsubscribing non-subscribed channels. s.chain.UnsubscribeFromBlocks(s.blockCh) s.chain.UnsubscribeFromTransactions(s.transactionCh) s.chain.UnsubscribeFromNotifications(s.notificationCh) s.chain.UnsubscribeFromExecutions(s.executionCh) if s.chain.P2PSigExtensionsEnabled() { s.coreServer.UnsubscribeFromNotaryRequests(s.notaryRequestCh) } s.subsLock.Unlock() drainloop: for { select { case <-s.blockCh: case <-s.executionCh: case <-s.notificationCh: case <-s.transactionCh: case <-s.notaryRequestCh: default: break drainloop } } // It's not required closing these, but since they're drained already // this is safe and it also allows to give a signal to Shutdown routine. close(s.blockCh) close(s.transactionCh) close(s.notificationCh) close(s.executionCh) close(s.notaryRequestCh) } func (s *Server) blockHeightFromParam(param *request.Param) (int, *response.Error) { num, err := param.GetInt() if err != nil { return 0, response.ErrInvalidParams } if num < 0 || num > int(s.chain.BlockHeight()) { return 0, invalidBlockHeightError(0, num) } return num, nil } func (s *Server) packResponse(r *request.In, result interface{}, respErr *response.Error) abstract { resp := abstract{ Header: response.Header{ JSONRPC: r.JSONRPC, ID: r.RawID, }, } if respErr != nil { resp.Error = respErr } else { resp.Result = result } return resp } // logRequestError is a request error logger. func (s *Server) logRequestError(r *request.Request, jsonErr *response.Error) { logFields := []zap.Field{ zap.String("cause", jsonErr.Data), } if r.In != nil { logFields = append(logFields, zap.String("method", r.In.Method)) params := request.Params(r.In.RawParams) logFields = append(logFields, zap.Any("params", params)) } logText := "Error encountered with rpc request" switch jsonErr.Code { case response.InternalServerErrorCode: s.log.Error(logText, logFields...) default: s.log.Info(logText, logFields...) } } // writeHTTPErrorResponse writes an error response to the ResponseWriter. func (s *Server) writeHTTPErrorResponse(r *request.In, w http.ResponseWriter, jsonErr *response.Error) { resp := s.packResponse(r, nil, jsonErr) s.writeHTTPServerResponse(&request.Request{In: r}, w, resp) } func (s *Server) writeHTTPServerResponse(r *request.Request, w http.ResponseWriter, resp abstractResult) { // Errors can happen in many places and we can only catch ALL of them here. resp.RunForErrors(func(jsonErr *response.Error) { s.logRequestError(r, jsonErr) }) if r.In != nil { resp := resp.(abstract) if resp.Error != nil { w.WriteHeader(getHTTPCodeForError(resp.Error)) } } w.Header().Set("Content-Type", "application/json; charset=utf-8") if s.config.EnableCORSWorkaround { w.Header().Set("Access-Control-Allow-Origin", "*") w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With") } encoder := json.NewEncoder(w) err := encoder.Encode(resp) if err != nil { switch { case r.In != nil: s.log.Error("Error encountered while encoding response", zap.String("err", err.Error()), zap.String("method", r.In.Method)) case r.Batch != nil: s.log.Error("Error encountered while encoding batch response", zap.String("err", err.Error())) } } } // validateAddress verifies that the address is a correct NEO address // see https://docs.neo.org/en-us/node/cli/2.9.4/api/validateaddress.html func validateAddress(addr interface{}) bool { if addr, ok := addr.(string); ok { _, err := address.StringToUint160(addr) return err == nil } return false } func escapeForLog(in string) string { return strings.Map(func(c rune) rune { if !strconv.IsGraphic(c) { return -1 } return c }, in) }