// Copyright (c) 2013-2017 The btcsuite developers // Copyright (c) 2015-2016 The Decred developers // Copyright (C) 2015-2017 The Lightning Network Developers package lnd import ( "context" "crypto/tls" "fmt" "io/ioutil" "net" "net/http" _ "net/http/pprof" // Blank import to set up profiling HTTP handlers. "os" "path/filepath" "runtime/pprof" "strconv" "strings" "sync" "time" "github.com/btcsuite/btcd/chaincfg/chainhash" "github.com/btcsuite/btcutil" "github.com/btcsuite/btcwallet/wallet" "github.com/btcsuite/btcwallet/walletdb" proxy "github.com/grpc-ecosystem/grpc-gateway/runtime" "github.com/lightninglabs/neutrino" "github.com/lightninglabs/neutrino/headerfs" "golang.org/x/crypto/acme/autocert" "google.golang.org/grpc" "google.golang.org/grpc/credentials" "gopkg.in/macaroon-bakery.v2/bakery" "gopkg.in/macaroon.v2" "github.com/lightningnetwork/lnd/autopilot" "github.com/lightningnetwork/lnd/build" "github.com/lightningnetwork/lnd/cert" "github.com/lightningnetwork/lnd/chainreg" "github.com/lightningnetwork/lnd/chanacceptor" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/keychain" "github.com/lightningnetwork/lnd/lncfg" "github.com/lightningnetwork/lnd/lnrpc" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwallet/btcwallet" "github.com/lightningnetwork/lnd/macaroons" "github.com/lightningnetwork/lnd/monitoring" "github.com/lightningnetwork/lnd/rpcperms" "github.com/lightningnetwork/lnd/signal" "github.com/lightningnetwork/lnd/tor" "github.com/lightningnetwork/lnd/walletunlocker" "github.com/lightningnetwork/lnd/watchtower" "github.com/lightningnetwork/lnd/watchtower/wtdb" ) // WalletUnlockerAuthOptions returns a list of DialOptions that can be used to // authenticate with the wallet unlocker service. // // NOTE: This should only be called after the WalletUnlocker listener has // signaled it is ready. func WalletUnlockerAuthOptions(cfg *Config) ([]grpc.DialOption, error) { creds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "") if err != nil { return nil, fmt.Errorf("unable to read TLS cert: %v", err) } // Create a dial options array with the TLS credentials. opts := []grpc.DialOption{ grpc.WithTransportCredentials(creds), } return opts, nil } // AdminAuthOptions returns a list of DialOptions that can be used to // authenticate with the RPC server with admin capabilities. // // NOTE: This should only be called after the RPCListener has signaled it is // ready. func AdminAuthOptions(cfg *Config) ([]grpc.DialOption, error) { creds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "") if err != nil { return nil, fmt.Errorf("unable to read TLS cert: %v", err) } // Create a dial options array. opts := []grpc.DialOption{ grpc.WithTransportCredentials(creds), } // Get the admin macaroon if macaroons are active. if !cfg.NoMacaroons { // Load the adming macaroon file. macBytes, err := ioutil.ReadFile(cfg.AdminMacPath) if err != nil { return nil, fmt.Errorf("unable to read macaroon "+ "path (check the network setting!): %v", err) } mac := &macaroon.Macaroon{} if err = mac.UnmarshalBinary(macBytes); err != nil { return nil, fmt.Errorf("unable to decode macaroon: %v", err) } // Now we append the macaroon credentials to the dial options. cred := macaroons.NewMacaroonCredential(mac) opts = append(opts, grpc.WithPerRPCCredentials(cred)) } return opts, nil } // GrpcRegistrar is an interface that must be satisfied by an external subserver // that wants to be able to register its own gRPC server onto lnd's main // grpc.Server instance. type GrpcRegistrar interface { // RegisterGrpcSubserver is called for each net.Listener on which lnd // creates a grpc.Server instance. External subservers implementing this // method can then register their own gRPC server structs to the main // server instance. RegisterGrpcSubserver(*grpc.Server) error } // RestRegistrar is an interface that must be satisfied by an external subserver // that wants to be able to register its own REST mux onto lnd's main // proxy.ServeMux instance. type RestRegistrar interface { // RegisterRestSubserver is called after lnd creates the main // proxy.ServeMux instance. External subservers implementing this method // can then register their own REST proxy stubs to the main server // instance. RegisterRestSubserver(context.Context, *proxy.ServeMux, string, []grpc.DialOption) error } // RPCSubserverConfig is a struct that can be used to register an external // subserver with the custom permissions that map to the gRPC server that is // going to be registered with the GrpcRegistrar. type RPCSubserverConfig struct { // Registrar is a callback that is invoked for each net.Listener on // which lnd creates a grpc.Server instance. Registrar GrpcRegistrar // Permissions is the permissions required for the external subserver. // It is a map between the full HTTP URI of each RPC and its required // macaroon permissions. If multiple action/entity tuples are specified // per URI, they are all required. See rpcserver.go for a list of valid // action and entity values. Permissions map[string][]bakery.Op // MacaroonValidator is a custom macaroon validator that should be used // instead of the default lnd validator. If specified, the custom // validator is used for all URIs specified in the above Permissions // map. MacaroonValidator macaroons.MacaroonValidator } // ListenerWithSignal is a net.Listener that has an additional Ready channel that // will be closed when a server starts listening. type ListenerWithSignal struct { net.Listener // Ready will be closed by the server listening on Listener. Ready chan struct{} } // ListenerCfg is a wrapper around custom listeners that can be passed to lnd // when calling its main method. type ListenerCfg struct { // WalletUnlocker can be set to the listener to use for the wallet // unlocker. If nil a regular network listener will be created. WalletUnlocker *ListenerWithSignal // RPCListener can be set to the listener to use for the RPC server. If // nil a regular network listener will be created. RPCListener *ListenerWithSignal // ExternalRPCSubserverCfg is optional and specifies the registration // callback and permissions to register external gRPC subservers. ExternalRPCSubserverCfg *RPCSubserverConfig // ExternalRestRegistrar is optional and specifies the registration // callback to register external REST subservers. ExternalRestRegistrar RestRegistrar } // Main is the true entry point for lnd. It accepts a fully populated and // validated main configuration struct and an optional listener config struct. // This function starts all main system components then blocks until a signal // is received on the shutdownChan at which point everything is shut down again. func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error { defer func() { ltndLog.Info("Shutdown complete\n") err := cfg.LogWriter.Close() if err != nil { ltndLog.Errorf("Could not close log rotator: %v", err) } }() // Show version at startup. ltndLog.Infof("Version: %s commit=%s, build=%s, logging=%s, debuglevel=%s", build.Version(), build.Commit, build.Deployment, build.LoggingType, cfg.DebugLevel) var network string switch { case cfg.Bitcoin.TestNet3 || cfg.Litecoin.TestNet3: network = "testnet" case cfg.Bitcoin.MainNet || cfg.Litecoin.MainNet: network = "mainnet" case cfg.Bitcoin.SimNet || cfg.Litecoin.SimNet: network = "simnet" case cfg.Bitcoin.RegTest || cfg.Litecoin.RegTest: network = "regtest" } ltndLog.Infof("Active chain: %v (network=%v)", strings.Title(cfg.registeredChains.PrimaryChain().String()), network, ) // Enable http profiling server if requested. if cfg.Profile != "" { go func() { listenAddr := net.JoinHostPort("", cfg.Profile) profileRedirect := http.RedirectHandler("/debug/pprof", http.StatusSeeOther) http.Handle("/", profileRedirect) fmt.Println(http.ListenAndServe(listenAddr, nil)) }() } // Write cpu profile if requested. if cfg.CPUProfile != "" { f, err := os.Create(cfg.CPUProfile) if err != nil { err := fmt.Errorf("unable to create CPU profile: %v", err) ltndLog.Error(err) return err } pprof.StartCPUProfile(f) defer f.Close() defer pprof.StopCPUProfile() } ctx := context.Background() ctx, cancel := context.WithCancel(ctx) defer cancel() localChanDB, remoteChanDB, cleanUp, err := initializeDatabases(ctx, cfg) switch { case err == channeldb.ErrDryRunMigrationOK: ltndLog.Infof("%v, exiting", err) return nil case err != nil: return fmt.Errorf("unable to open databases: %v", err) } defer cleanUp() // Only process macaroons if --no-macaroons isn't set. serverOpts, restDialOpts, restListen, cleanUp, err := getTLSConfig(cfg) if err != nil { err := fmt.Errorf("unable to load TLS credentials: %v", err) ltndLog.Error(err) return err } defer cleanUp() // Before starting the wallet, we'll create and start our Neutrino // light client instance, if enabled, in order to allow it to sync // while the rest of the daemon continues startup. mainChain := cfg.Bitcoin if cfg.registeredChains.PrimaryChain() == chainreg.LitecoinChain { mainChain = cfg.Litecoin } var neutrinoCS *neutrino.ChainService if mainChain.Node == "neutrino" { neutrinoBackend, neutrinoCleanUp, err := initNeutrinoBackend( cfg, mainChain.ChainDir, ) if err != nil { err := fmt.Errorf("unable to initialize neutrino "+ "backend: %v", err) ltndLog.Error(err) return err } defer neutrinoCleanUp() neutrinoCS = neutrinoBackend } var ( walletInitParams = WalletUnlockParams{ MacResponseChan: make(chan []byte), } privateWalletPw = lnwallet.DefaultPrivatePassphrase publicWalletPw = lnwallet.DefaultPublicPassphrase ) // If the user didn't request a seed, then we'll manually assume a // wallet birthday of now, as otherwise the seed would've specified // this information. walletInitParams.Birthday = time.Now() // If we have chosen to start with a dedicated listener for the // rpc server, we set it directly. var grpcListeners []*ListenerWithSignal if lisCfg.RPCListener != nil { grpcListeners = []*ListenerWithSignal{lisCfg.RPCListener} } else { // Otherwise we create listeners from the RPCListeners defined // in the config. for _, grpcEndpoint := range cfg.RPCListeners { // Start a gRPC server listening for HTTP/2 // connections. lis, err := lncfg.ListenOnAddress(grpcEndpoint) if err != nil { ltndLog.Errorf("unable to listen on %s", grpcEndpoint) return err } defer lis.Close() grpcListeners = append( grpcListeners, &ListenerWithSignal{ Listener: lis, Ready: make(chan struct{}), }) } } // We'll create the WalletUnlockerService and check whether the wallet // already exists. pwService := createWalletUnlockerService(cfg) walletExists, err := pwService.WalletExists() if err != nil { return err } // Create a new RPC interceptor that we'll add to the GRPC server. This // will be used to log the API calls invoked on the GRPC server. interceptorChain := rpcperms.NewInterceptorChain( rpcsLog, cfg.NoMacaroons, walletExists, ) if err := interceptorChain.Start(); err != nil { return err } defer func() { err := interceptorChain.Stop() if err != nil { ltndLog.Warnf("error stopping RPC interceptor "+ "chain: %v", err) } }() rpcServerOpts := interceptorChain.CreateServerOpts() serverOpts = append(serverOpts, rpcServerOpts...) grpcServer := grpc.NewServer(serverOpts...) defer grpcServer.Stop() // Register the WalletUnlockerService with the GRPC server. lnrpc.RegisterWalletUnlockerServer(grpcServer, pwService) // We'll also register the RPC interceptor chain as the StateServer, as // it can be used to query for the current state of the wallet. lnrpc.RegisterStateServer(grpcServer, interceptorChain) // Initialize, and register our implementation of the gRPC interface // exported by the rpcServer. rpcServer := newRPCServer( cfg, interceptorChain, lisCfg.ExternalRPCSubserverCfg, lisCfg.ExternalRestRegistrar, ) err = rpcServer.RegisterWithGrpcServer(grpcServer) if err != nil { return err } // Now that both the WalletUnlocker and LightningService have been // registered with the GRPC server, we can start listening. err = startGrpcListen(cfg, grpcServer, grpcListeners) if err != nil { return err } // Now start the REST proxy for our gRPC server above. We'll ensure // we direct LND to connect to its loopback address rather than a // wildcard to prevent certificate issues when accessing the proxy // externally. stopProxy, err := startRestProxy( cfg, rpcServer, restDialOpts, restListen, ) if err != nil { return err } defer stopProxy() // We wait until the user provides a password over RPC. In case lnd is // started with the --noseedbackup flag, we use the default password // for wallet encryption. if !cfg.NoSeedBackup { params, err := waitForWalletPassword(cfg, pwService) if err != nil { err := fmt.Errorf("unable to set up wallet password "+ "listeners: %v", err) ltndLog.Error(err) return err } walletInitParams = *params privateWalletPw = walletInitParams.Password publicWalletPw = walletInitParams.Password defer func() { if err := walletInitParams.UnloadWallet(); err != nil { ltndLog.Errorf("Could not unload wallet: %v", err) } }() if walletInitParams.RecoveryWindow > 0 { ltndLog.Infof("Wallet recovery mode enabled with "+ "address lookahead of %d addresses", walletInitParams.RecoveryWindow) } } var macaroonService *macaroons.Service if !cfg.NoMacaroons { // Create the macaroon authentication/authorization service. macaroonService, err = macaroons.NewService( cfg.networkDir, "lnd", walletInitParams.StatelessInit, cfg.DB.Bolt.DBTimeout, macaroons.IPLockChecker, ) if err != nil { err := fmt.Errorf("unable to set up macaroon "+ "authentication: %v", err) ltndLog.Error(err) return err } defer macaroonService.Close() // Try to unlock the macaroon store with the private password. // Ignore ErrAlreadyUnlocked since it could be unlocked by the // wallet unlocker. err = macaroonService.CreateUnlock(&privateWalletPw) if err != nil && err != macaroons.ErrAlreadyUnlocked { err := fmt.Errorf("unable to unlock macaroons: %v", err) ltndLog.Error(err) return err } // In case we actually needed to unlock the wallet, we now need // to create an instance of the admin macaroon and send it to // the unlocker so it can forward it to the user. In no seed // backup mode, there's nobody listening on the channel and we'd // block here forever. if !cfg.NoSeedBackup { adminMacBytes, err := bakeMacaroon( ctx, macaroonService, adminPermissions(), ) if err != nil { return err } // The channel is buffered by one element so writing // should not block here. walletInitParams.MacResponseChan <- adminMacBytes } // If the user requested a stateless initialization, no macaroon // files should be created. if !walletInitParams.StatelessInit && !fileExists(cfg.AdminMacPath) && !fileExists(cfg.ReadMacPath) && !fileExists(cfg.InvoiceMacPath) { // Create macaroon files for lncli to use if they don't // exist. err = genMacaroons( ctx, macaroonService, cfg.AdminMacPath, cfg.ReadMacPath, cfg.InvoiceMacPath, ) if err != nil { err := fmt.Errorf("unable to create macaroons "+ "%v", err) ltndLog.Error(err) return err } } // As a security service to the user, if they requested // stateless initialization and there are macaroon files on disk // we log a warning. if walletInitParams.StatelessInit { msg := "Found %s macaroon on disk (%s) even though " + "--stateless_init was requested. Unencrypted " + "state is accessible by the host system. You " + "should change the password and use " + "--new_mac_root_key with --stateless_init to " + "clean up and invalidate old macaroons." if fileExists(cfg.AdminMacPath) { ltndLog.Warnf(msg, "admin", cfg.AdminMacPath) } if fileExists(cfg.ReadMacPath) { ltndLog.Warnf(msg, "readonly", cfg.ReadMacPath) } if fileExists(cfg.InvoiceMacPath) { ltndLog.Warnf(msg, "invoice", cfg.InvoiceMacPath) } } // We add the macaroon service to our RPC interceptor. This // will start checking macaroons against permissions on every // RPC invocation. interceptorChain.AddMacaroonService(macaroonService) } // Now that the wallet password has been provided, transition the RPC // state into Unlocked. interceptorChain.SetWalletUnlocked() // Since calls to the WalletUnlocker service wait for a response on the // macaroon channel, we close it here to make sure they return in case // we did not return the admin macaroon above. This will be the case if // --no-macaroons is used. close(walletInitParams.MacResponseChan) // With the information parsed from the configuration, create valid // instances of the pertinent interfaces required to operate the // Lightning Network Daemon. // // When we create the chain control, we need storage for the height // hints and also the wallet itself, for these two we want them to be // replicated, so we'll pass in the remote channel DB instance. chainControlCfg := &chainreg.Config{ Bitcoin: cfg.Bitcoin, Litecoin: cfg.Litecoin, PrimaryChain: cfg.registeredChains.PrimaryChain, HeightHintCacheQueryDisable: cfg.HeightHintCacheQueryDisable, NeutrinoMode: cfg.NeutrinoMode, BitcoindMode: cfg.BitcoindMode, LitecoindMode: cfg.LitecoindMode, BtcdMode: cfg.BtcdMode, LtcdMode: cfg.LtcdMode, LocalChanDB: localChanDB, RemoteChanDB: remoteChanDB, PrivateWalletPw: privateWalletPw, PublicWalletPw: publicWalletPw, Birthday: walletInitParams.Birthday, RecoveryWindow: walletInitParams.RecoveryWindow, Wallet: walletInitParams.Wallet, DBTimeOut: cfg.DB.Bolt.DBTimeout, NeutrinoCS: neutrinoCS, ActiveNetParams: cfg.ActiveNetParams, FeeURL: cfg.FeeURL, } activeChainControl, err := chainreg.NewChainControl(chainControlCfg) if err != nil { err := fmt.Errorf("unable to create chain control: %v", err) ltndLog.Error(err) return err } // Finally before we start the server, we'll register the "holy // trinity" of interface for our current "home chain" with the active // chainRegistry interface. primaryChain := cfg.registeredChains.PrimaryChain() cfg.registeredChains.RegisterChain(primaryChain, activeChainControl) // TODO(roasbeef): add rotation idKeyDesc, err := activeChainControl.KeyRing.DeriveKey( keychain.KeyLocator{ Family: keychain.KeyFamilyNodeKey, Index: 0, }, ) if err != nil { err := fmt.Errorf("error deriving node key: %v", err) ltndLog.Error(err) return err } if cfg.Tor.Active { srvrLog.Infof("Proxying all network traffic via Tor "+ "(stream_isolation=%v)! NOTE: Ensure the backend node "+ "is proxying over Tor as well", cfg.Tor.StreamIsolation) } // If the watchtower client should be active, open the client database. // This is done here so that Close always executes when lndMain returns. var towerClientDB *wtdb.ClientDB if cfg.WtClient.Active { var err error towerClientDB, err = wtdb.OpenClientDB( cfg.localDatabaseDir(), cfg.DB.Bolt.DBTimeout, ) if err != nil { err := fmt.Errorf("unable to open watchtower client "+ "database: %v", err) ltndLog.Error(err) return err } defer towerClientDB.Close() } // If tor is active and either v2 or v3 onion services have been specified, // make a tor controller and pass it into both the watchtower server and // the regular lnd server. var torController *tor.Controller if cfg.Tor.Active && (cfg.Tor.V2 || cfg.Tor.V3) { torController = tor.NewController( cfg.Tor.Control, cfg.Tor.TargetIPAddress, cfg.Tor.Password, ) // Start the tor controller before giving it to any other subsystems. if err := torController.Start(); err != nil { err := fmt.Errorf("unable to initialize tor controller: %v", err) ltndLog.Error(err) return err } defer func() { if err := torController.Stop(); err != nil { ltndLog.Errorf("error stopping tor controller: %v", err) } }() } var tower *watchtower.Standalone if cfg.Watchtower.Active { // Segment the watchtower directory by chain and network. towerDBDir := filepath.Join( cfg.Watchtower.TowerDir, cfg.registeredChains.PrimaryChain().String(), lncfg.NormalizeNetwork(cfg.ActiveNetParams.Name), ) towerDB, err := wtdb.OpenTowerDB( towerDBDir, cfg.DB.Bolt.DBTimeout, ) if err != nil { err := fmt.Errorf("unable to open watchtower "+ "database: %v", err) ltndLog.Error(err) return err } defer towerDB.Close() towerKeyDesc, err := activeChainControl.KeyRing.DeriveKey( keychain.KeyLocator{ Family: keychain.KeyFamilyTowerID, Index: 0, }, ) if err != nil { err := fmt.Errorf("error deriving tower key: %v", err) ltndLog.Error(err) return err } wtCfg := &watchtower.Config{ BlockFetcher: activeChainControl.ChainIO, DB: towerDB, EpochRegistrar: activeChainControl.ChainNotifier, Net: cfg.net, NewAddress: func() (btcutil.Address, error) { return activeChainControl.Wallet.NewAddress( lnwallet.WitnessPubKey, false, ) }, NodeKeyECDH: keychain.NewPubKeyECDH( towerKeyDesc, activeChainControl.KeyRing, ), PublishTx: activeChainControl.Wallet.PublishTransaction, ChainHash: *cfg.ActiveNetParams.GenesisHash, } // If there is a tor controller (user wants auto hidden services), then // store a pointer in the watchtower config. if torController != nil { wtCfg.TorController = torController wtCfg.WatchtowerKeyPath = cfg.Tor.WatchtowerKeyPath switch { case cfg.Tor.V2: wtCfg.Type = tor.V2 case cfg.Tor.V3: wtCfg.Type = tor.V3 } } wtConfig, err := cfg.Watchtower.Apply(wtCfg, lncfg.NormalizeAddresses) if err != nil { err := fmt.Errorf("unable to configure watchtower: %v", err) ltndLog.Error(err) return err } tower, err = watchtower.New(wtConfig) if err != nil { err := fmt.Errorf("unable to create watchtower: %v", err) ltndLog.Error(err) return err } } // Initialize the ChainedAcceptor. chainedAcceptor := chanacceptor.NewChainedAcceptor() // Set up the core server which will listen for incoming peer // connections. server, err := newServer( cfg, cfg.Listeners, localChanDB, remoteChanDB, towerClientDB, activeChainControl, &idKeyDesc, walletInitParams.ChansToRestore, chainedAcceptor, torController, ) if err != nil { err := fmt.Errorf("unable to create server: %v", err) ltndLog.Error(err) return err } // Set up an autopilot manager from the current config. This will be // used to manage the underlying autopilot agent, starting and stopping // it at will. atplCfg, err := initAutoPilot(server, cfg.Autopilot, mainChain, cfg.ActiveNetParams) if err != nil { err := fmt.Errorf("unable to initialize autopilot: %v", err) ltndLog.Error(err) return err } atplManager, err := autopilot.NewManager(atplCfg) if err != nil { err := fmt.Errorf("unable to create autopilot manager: %v", err) ltndLog.Error(err) return err } if err := atplManager.Start(); err != nil { err := fmt.Errorf("unable to start autopilot manager: %v", err) ltndLog.Error(err) return err } defer atplManager.Stop() // Now we have created all dependencies necessary to populate and // start the RPC server. err = rpcServer.addDeps( server, macaroonService, cfg.SubRPCServers, atplManager, server.invoices, tower, chainedAcceptor, ) if err != nil { err := fmt.Errorf("unable to add deps to RPC server: %v", err) ltndLog.Error(err) return err } if err := rpcServer.Start(); err != nil { err := fmt.Errorf("unable to start RPC server: %v", err) ltndLog.Error(err) return err } defer rpcServer.Stop() // We transition the RPC state to Active, as the RPC server is up. interceptorChain.SetRPCActive() // If we're not in regtest or simnet mode, We'll wait until we're fully // synced to continue the start up of the remainder of the daemon. This // ensures that we don't accept any possibly invalid state transitions, or // accept channels with spent funds. if !(cfg.Bitcoin.RegTest || cfg.Bitcoin.SimNet || cfg.Litecoin.RegTest || cfg.Litecoin.SimNet) { _, bestHeight, err := activeChainControl.ChainIO.GetBestBlock() if err != nil { err := fmt.Errorf("unable to determine chain tip: %v", err) ltndLog.Error(err) return err } ltndLog.Infof("Waiting for chain backend to finish sync, "+ "start_height=%v", bestHeight) for { if !signal.Alive() { return nil } synced, _, err := activeChainControl.Wallet.IsSynced() if err != nil { err := fmt.Errorf("unable to determine if "+ "wallet is synced: %v", err) ltndLog.Error(err) return err } if synced { break } time.Sleep(time.Second * 1) } _, bestHeight, err = activeChainControl.ChainIO.GetBestBlock() if err != nil { err := fmt.Errorf("unable to determine chain tip: %v", err) ltndLog.Error(err) return err } ltndLog.Infof("Chain backend is fully synced (end_height=%v)!", bestHeight) } // With all the relevant chains initialized, we can finally start the // server itself. if err := server.Start(); err != nil { err := fmt.Errorf("unable to start server: %v", err) ltndLog.Error(err) return err } defer server.Stop() // Now that the server has started, if the autopilot mode is currently // active, then we'll start the autopilot agent immediately. It will be // stopped together with the autopilot service. if cfg.Autopilot.Active { if err := atplManager.StartAgent(); err != nil { err := fmt.Errorf("unable to start autopilot agent: %v", err) ltndLog.Error(err) return err } } if cfg.Watchtower.Active { if err := tower.Start(); err != nil { err := fmt.Errorf("unable to start watchtower: %v", err) ltndLog.Error(err) return err } defer tower.Stop() } // Wait for shutdown signal from either a graceful server stop or from // the interrupt handler. <-shutdownChan return nil } // getTLSConfig returns a TLS configuration for the gRPC server and credentials // and a proxy destination for the REST reverse proxy. func getTLSConfig(cfg *Config) ([]grpc.ServerOption, []grpc.DialOption, func(net.Addr) (net.Listener, error), func(), error) { // Ensure we create TLS key and certificate if they don't exist. if !fileExists(cfg.TLSCertPath) && !fileExists(cfg.TLSKeyPath) { rpcsLog.Infof("Generating TLS certificates...") err := cert.GenCertPair( "lnd autogenerated cert", cfg.TLSCertPath, cfg.TLSKeyPath, cfg.TLSExtraIPs, cfg.TLSExtraDomains, cfg.TLSDisableAutofill, cert.DefaultAutogenValidity, ) if err != nil { return nil, nil, nil, nil, err } rpcsLog.Infof("Done generating TLS certificates") } certData, parsedCert, err := cert.LoadCert( cfg.TLSCertPath, cfg.TLSKeyPath, ) if err != nil { return nil, nil, nil, nil, err } // We check whether the certifcate we have on disk match the IPs and // domains specified by the config. If the extra IPs or domains have // changed from when the certificate was created, we will refresh the // certificate if auto refresh is active. refresh := false if cfg.TLSAutoRefresh { refresh, err = cert.IsOutdated( parsedCert, cfg.TLSExtraIPs, cfg.TLSExtraDomains, cfg.TLSDisableAutofill, ) if err != nil { return nil, nil, nil, nil, err } } // If the certificate expired or it was outdated, delete it and the TLS // key and generate a new pair. if time.Now().After(parsedCert.NotAfter) || refresh { ltndLog.Info("TLS certificate is expired or outdated, " + "generating a new one") err := os.Remove(cfg.TLSCertPath) if err != nil { return nil, nil, nil, nil, err } err = os.Remove(cfg.TLSKeyPath) if err != nil { return nil, nil, nil, nil, err } rpcsLog.Infof("Renewing TLS certificates...") err = cert.GenCertPair( "lnd autogenerated cert", cfg.TLSCertPath, cfg.TLSKeyPath, cfg.TLSExtraIPs, cfg.TLSExtraDomains, cfg.TLSDisableAutofill, cert.DefaultAutogenValidity, ) if err != nil { return nil, nil, nil, nil, err } rpcsLog.Infof("Done renewing TLS certificates") // Reload the certificate data. certData, _, err = cert.LoadCert( cfg.TLSCertPath, cfg.TLSKeyPath, ) if err != nil { return nil, nil, nil, nil, err } } tlsCfg := cert.TLSConfFromCert(certData) restCreds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "") if err != nil { return nil, nil, nil, nil, err } // If Let's Encrypt is enabled, instantiate autocert to request/renew // the certificates. cleanUp := func() {} if cfg.LetsEncryptDomain != "" { ltndLog.Infof("Using Let's Encrypt certificate for domain %v", cfg.LetsEncryptDomain) manager := autocert.Manager{ Cache: autocert.DirCache(cfg.LetsEncryptDir), Prompt: autocert.AcceptTOS, HostPolicy: autocert.HostWhitelist(cfg.LetsEncryptDomain), } srv := &http.Server{ Addr: cfg.LetsEncryptListen, Handler: manager.HTTPHandler(nil), } shutdownCompleted := make(chan struct{}) cleanUp = func() { err := srv.Shutdown(context.Background()) if err != nil { ltndLog.Errorf("Autocert listener shutdown "+ " error: %v", err) return } <-shutdownCompleted ltndLog.Infof("Autocert challenge listener stopped") } go func() { ltndLog.Infof("Autocert challenge listener started "+ "at %v", cfg.LetsEncryptListen) err := srv.ListenAndServe() if err != http.ErrServerClosed { ltndLog.Errorf("autocert http: %v", err) } close(shutdownCompleted) }() getCertificate := func(h *tls.ClientHelloInfo) ( *tls.Certificate, error) { lecert, err := manager.GetCertificate(h) if err != nil { ltndLog.Errorf("GetCertificate: %v", err) return &certData, nil } return lecert, err } // The self-signed tls.cert remains available as fallback. tlsCfg.GetCertificate = getCertificate } serverCreds := credentials.NewTLS(tlsCfg) serverOpts := []grpc.ServerOption{grpc.Creds(serverCreds)} // For our REST dial options, we'll still use TLS, but also increase // the max message size that we'll decode to allow clients to hit // endpoints which return more data such as the DescribeGraph call. // We set this to 200MiB atm. Should be the same value as maxMsgRecvSize // in cmd/lncli/main.go. restDialOpts := []grpc.DialOption{ grpc.WithTransportCredentials(restCreds), grpc.WithDefaultCallOptions( grpc.MaxCallRecvMsgSize(1 * 1024 * 1024 * 200), ), } // Return a function closure that can be used to listen on a given // address with the current TLS config. restListen := func(addr net.Addr) (net.Listener, error) { // For restListen we will call ListenOnAddress if TLS is // disabled. if cfg.DisableRestTLS { return lncfg.ListenOnAddress(addr) } return lncfg.TLSListenOnAddress(addr, tlsCfg) } return serverOpts, restDialOpts, restListen, cleanUp, nil } // fileExists reports whether the named file or directory exists. // This function is taken from https://github.com/btcsuite/btcd func fileExists(name string) bool { if _, err := os.Stat(name); err != nil { if os.IsNotExist(err) { return false } } return true } // bakeMacaroon creates a new macaroon with newest version and the given // permissions then returns it binary serialized. func bakeMacaroon(ctx context.Context, svc *macaroons.Service, permissions []bakery.Op) ([]byte, error) { mac, err := svc.NewMacaroon( ctx, macaroons.DefaultRootKeyID, permissions..., ) if err != nil { return nil, err } return mac.M().MarshalBinary() } // genMacaroons generates three macaroon files; one admin-level, one for // invoice access and one read-only. These can also be used to generate more // granular macaroons. func genMacaroons(ctx context.Context, svc *macaroons.Service, admFile, roFile, invoiceFile string) error { // First, we'll generate a macaroon that only allows the caller to // access invoice related calls. This is useful for merchants and other // services to allow an isolated instance that can only query and // modify invoices. invoiceMacBytes, err := bakeMacaroon(ctx, svc, invoicePermissions) if err != nil { return err } err = ioutil.WriteFile(invoiceFile, invoiceMacBytes, 0644) if err != nil { _ = os.Remove(invoiceFile) return err } // Generate the read-only macaroon and write it to a file. roBytes, err := bakeMacaroon(ctx, svc, readPermissions) if err != nil { return err } if err = ioutil.WriteFile(roFile, roBytes, 0644); err != nil { _ = os.Remove(roFile) return err } // Generate the admin macaroon and write it to a file. admBytes, err := bakeMacaroon(ctx, svc, adminPermissions()) if err != nil { return err } if err = ioutil.WriteFile(admFile, admBytes, 0600); err != nil { _ = os.Remove(admFile) return err } return nil } // adminPermissions returns a list of all permissions in a safe way that doesn't // modify any of the source lists. func adminPermissions() []bakery.Op { admin := make([]bakery.Op, len(readPermissions)+len(writePermissions)) copy(admin[:len(readPermissions)], readPermissions) copy(admin[len(readPermissions):], writePermissions) return admin } // WalletUnlockParams holds the variables used to parameterize the unlocking of // lnd's wallet after it has already been created. type WalletUnlockParams struct { // Password is the public and private wallet passphrase. Password []byte // Birthday specifies the approximate time that this wallet was created. // This is used to bound any rescans on startup. Birthday time.Time // RecoveryWindow specifies the address lookahead when entering recovery // mode. A recovery will be attempted if this value is non-zero. RecoveryWindow uint32 // Wallet is the loaded and unlocked Wallet. This is returned // from the unlocker service to avoid it being unlocked twice (once in // the unlocker service to check if the password is correct and again // later when lnd actually uses it). Because unlocking involves scrypt // which is resource intensive, we want to avoid doing it twice. Wallet *wallet.Wallet // ChansToRestore a set of static channel backups that should be // restored before the main server instance starts up. ChansToRestore walletunlocker.ChannelsToRecover // UnloadWallet is a function for unloading the wallet, which should // be called on shutdown. UnloadWallet func() error // StatelessInit signals that the user requested the daemon to be // initialized stateless, which means no unencrypted macaroons should be // written to disk. StatelessInit bool // MacResponseChan is the channel for sending back the admin macaroon to // the WalletUnlocker service. MacResponseChan chan []byte } // createWalletUnlockerService creates a WalletUnlockerService from the passed // config. func createWalletUnlockerService(cfg *Config) *walletunlocker.UnlockerService { chainConfig := cfg.Bitcoin if cfg.registeredChains.PrimaryChain() == chainreg.LitecoinChain { chainConfig = cfg.Litecoin } // The macaroonFiles are passed to the wallet unlocker so they can be // deleted and recreated in case the root macaroon key is also changed // during the change password operation. macaroonFiles := []string{ cfg.AdminMacPath, cfg.ReadMacPath, cfg.InvoiceMacPath, } return walletunlocker.New( chainConfig.ChainDir, cfg.ActiveNetParams.Params, !cfg.SyncFreelist, macaroonFiles, cfg.DB.Bolt.DBTimeout, cfg.ResetWalletTransactions, ) } // startGrpcListen starts the GRPC server on the passed listeners. func startGrpcListen(cfg *Config, grpcServer *grpc.Server, listeners []*ListenerWithSignal) error { // Use a WaitGroup so we can be sure the instructions on how to input the // password is the last thing to be printed to the console. var wg sync.WaitGroup for _, lis := range listeners { wg.Add(1) go func(lis *ListenerWithSignal) { rpcsLog.Infof("RPC server listening on %s", lis.Addr()) // Close the ready chan to indicate we are listening. close(lis.Ready) wg.Done() _ = grpcServer.Serve(lis) }(lis) } // If Prometheus monitoring is enabled, start the Prometheus exporter. if cfg.Prometheus.Enabled() { err := monitoring.ExportPrometheusMetrics( grpcServer, cfg.Prometheus, ) if err != nil { return err } } // Wait for gRPC servers to be up running. wg.Wait() return nil } // startRestProxy starts the given REST proxy on the listeners found in the // config. func startRestProxy(cfg *Config, rpcServer *rpcServer, restDialOpts []grpc.DialOption, restListen func(net.Addr) (net.Listener, error)) (func(), error) { // We use the first RPC listener as the destination for our REST proxy. // If the listener is set to listen on all interfaces, we replace it // with localhost, as we cannot dial it directly. restProxyDest := cfg.RPCListeners[0].String() switch { case strings.Contains(restProxyDest, "0.0.0.0"): restProxyDest = strings.Replace( restProxyDest, "0.0.0.0", "127.0.0.1", 1, ) case strings.Contains(restProxyDest, "[::]"): restProxyDest = strings.Replace( restProxyDest, "[::]", "[::1]", 1, ) } var shutdownFuncs []func() shutdown := func() { for _, shutdownFn := range shutdownFuncs { shutdownFn() } } // Start a REST proxy for our gRPC server. ctx := context.Background() ctx, cancel := context.WithCancel(ctx) shutdownFuncs = append(shutdownFuncs, cancel) // We'll set up a proxy that will forward REST calls to the GRPC // server. // // The default JSON marshaler of the REST proxy only sets OrigName to // true, which instructs it to use the same field names as specified in // the proto file and not switch to camel case. What we also want is // that the marshaler prints all values, even if they are falsey. customMarshalerOption := proxy.WithMarshalerOption( proxy.MIMEWildcard, &proxy.JSONPb{ OrigName: true, EmitDefaults: true, }, ) mux := proxy.NewServeMux(customMarshalerOption) // Register our services with the REST proxy. err := lnrpc.RegisterWalletUnlockerHandlerFromEndpoint( ctx, mux, restProxyDest, restDialOpts, ) if err != nil { return nil, err } err = lnrpc.RegisterStateHandlerFromEndpoint( ctx, mux, restProxyDest, restDialOpts, ) if err != nil { return nil, err } err = rpcServer.RegisterWithRestProxy( ctx, mux, restDialOpts, restProxyDest, ) if err != nil { return nil, err } // Wrap the default grpc-gateway handler with the WebSocket handler. restHandler := lnrpc.NewWebSocketProxy(mux, rpcsLog) // Use a WaitGroup so we can be sure the instructions on how to input the // password is the last thing to be printed to the console. var wg sync.WaitGroup // Now spin up a network listener for each requested port and start a // goroutine that serves REST with the created mux there. for _, restEndpoint := range cfg.RESTListeners { lis, err := restListen(restEndpoint) if err != nil { ltndLog.Errorf("gRPC proxy unable to listen on %s", restEndpoint) return nil, err } shutdownFuncs = append(shutdownFuncs, func() { err := lis.Close() if err != nil { rpcsLog.Errorf("Error closing listener: %v", err) } }) wg.Add(1) go func() { rpcsLog.Infof("gRPC proxy started at %s", lis.Addr()) // Create our proxy chain now. A request will pass // through the following chain: // req ---> CORS handler --> WS proxy ---> // REST proxy --> gRPC endpoint corsHandler := allowCORS(restHandler, cfg.RestCORS) wg.Done() err := http.Serve(lis, corsHandler) if err != nil && !lnrpc.IsClosedConnError(err) { rpcsLog.Error(err) } }() } // Wait for REST servers to be up running. wg.Wait() return shutdown, nil } // waitForWalletPassword blocks until a password is provided by the user to // this RPC server. func waitForWalletPassword(cfg *Config, pwService *walletunlocker.UnlockerService) (*WalletUnlockParams, error) { chainConfig := cfg.Bitcoin if cfg.registeredChains.PrimaryChain() == chainreg.LitecoinChain { chainConfig = cfg.Litecoin } // Wait for user to provide the password. ltndLog.Infof("Waiting for wallet encryption password. Use `lncli " + "create` to create a wallet, `lncli unlock` to unlock an " + "existing wallet, or `lncli changepassword` to change the " + "password of an existing wallet and unlock it.") // We currently don't distinguish between getting a password to be used // for creation or unlocking, as a new wallet db will be created if // none exists when creating the chain control. select { // The wallet is being created for the first time, we'll check to see // if the user provided any entropy for seed creation. If so, then // we'll create the wallet early to load the seed. case initMsg := <-pwService.InitMsgs: password := initMsg.Passphrase cipherSeed := initMsg.WalletSeed recoveryWindow := initMsg.RecoveryWindow // Before we proceed, we'll check the internal version of the // seed. If it's greater than the current key derivation // version, then we'll return an error as we don't understand // this. if cipherSeed.InternalVersion != keychain.KeyDerivationVersion { return nil, fmt.Errorf("invalid internal "+ "seed version %v, current version is %v", cipherSeed.InternalVersion, keychain.KeyDerivationVersion) } netDir := btcwallet.NetworkDir( chainConfig.ChainDir, cfg.ActiveNetParams.Params, ) loader := wallet.NewLoader( cfg.ActiveNetParams.Params, netDir, !cfg.SyncFreelist, cfg.DB.Bolt.DBTimeout, recoveryWindow, ) // With the seed, we can now use the wallet loader to create // the wallet, then pass it back to avoid unlocking it again. birthday := cipherSeed.BirthdayTime() newWallet, err := loader.CreateNewWallet( password, password, cipherSeed.Entropy[:], birthday, ) if err != nil { // Don't leave the file open in case the new wallet // could not be created for whatever reason. if err := loader.UnloadWallet(); err != nil { ltndLog.Errorf("Could not unload new "+ "wallet: %v", err) } return nil, err } // For new wallets, the ResetWalletTransactions flag is a no-op. if cfg.ResetWalletTransactions { ltndLog.Warnf("Ignoring reset-wallet-transactions " + "flag for new wallet as it has no effect") } return &WalletUnlockParams{ Password: password, Birthday: birthday, RecoveryWindow: recoveryWindow, Wallet: newWallet, ChansToRestore: initMsg.ChanBackups, UnloadWallet: loader.UnloadWallet, StatelessInit: initMsg.StatelessInit, MacResponseChan: pwService.MacResponseChan, }, nil // The wallet has already been created in the past, and is simply being // unlocked. So we'll just return these passphrases. case unlockMsg := <-pwService.UnlockMsgs: // Resetting the transactions is something the user likely only // wants to do once so we add a prominent warning to the log to // remind the user to turn off the setting again after // successful completion. if cfg.ResetWalletTransactions { ltndLog.Warnf("Dropped all transaction history from " + "on-chain wallet. Remember to disable " + "reset-wallet-transactions flag for next " + "start of lnd") } return &WalletUnlockParams{ Password: unlockMsg.Passphrase, RecoveryWindow: unlockMsg.RecoveryWindow, Wallet: unlockMsg.Wallet, ChansToRestore: unlockMsg.ChanBackups, UnloadWallet: unlockMsg.UnloadWallet, StatelessInit: unlockMsg.StatelessInit, MacResponseChan: pwService.MacResponseChan, }, nil case <-signal.ShutdownChannel(): return nil, fmt.Errorf("shutting down") } } // initializeDatabases extracts the current databases that we'll use for normal // operation in the daemon. Two databases are returned: one remote and one // local. However, only if the replicated database is active will the remote // database point to a unique database. Otherwise, the local and remote DB will // both point to the same local database. A function closure that closes all // opened databases is also returned. func initializeDatabases(ctx context.Context, cfg *Config) (*channeldb.DB, *channeldb.DB, func(), error) { ltndLog.Infof("Opening the main database, this might take a few " + "minutes...") if cfg.DB.Backend == lncfg.BoltBackend { ltndLog.Infof("Opening bbolt database, sync_freelist=%v, "+ "auto_compact=%v", cfg.DB.Bolt.SyncFreelist, cfg.DB.Bolt.AutoCompact) } startOpenTime := time.Now() databaseBackends, err := cfg.DB.GetBackends( ctx, cfg.localDatabaseDir(), cfg.networkName(), ) if err != nil { return nil, nil, nil, fmt.Errorf("unable to obtain database "+ "backends: %v", err) } // If the remoteDB is nil, then we'll just open a local DB as normal, // having the remote and local pointer be the exact same instance. var ( localChanDB, remoteChanDB *channeldb.DB closeFuncs []func() ) if databaseBackends.RemoteDB == nil { // Open the channeldb, which is dedicated to storing channel, // and network related metadata. localChanDB, err = channeldb.CreateWithBackend( databaseBackends.LocalDB, channeldb.OptionSetRejectCacheSize(cfg.Caches.RejectCacheSize), channeldb.OptionSetChannelCacheSize(cfg.Caches.ChannelCacheSize), channeldb.OptionSetBatchCommitInterval(cfg.DB.BatchCommitInterval), channeldb.OptionDryRunMigration(cfg.DryRunMigration), ) switch { case err == channeldb.ErrDryRunMigrationOK: return nil, nil, nil, err case err != nil: err := fmt.Errorf("unable to open local channeldb: %v", err) ltndLog.Error(err) return nil, nil, nil, err } closeFuncs = append(closeFuncs, func() { localChanDB.Close() }) remoteChanDB = localChanDB } else { ltndLog.Infof("Database replication is available! Creating " + "local and remote channeldb instances") // Otherwise, we'll open two instances, one for the state we // only need locally, and the other for things we want to // ensure are replicated. localChanDB, err = channeldb.CreateWithBackend( databaseBackends.LocalDB, channeldb.OptionSetRejectCacheSize(cfg.Caches.RejectCacheSize), channeldb.OptionSetChannelCacheSize(cfg.Caches.ChannelCacheSize), channeldb.OptionSetBatchCommitInterval(cfg.DB.BatchCommitInterval), channeldb.OptionDryRunMigration(cfg.DryRunMigration), ) switch { // As we want to allow both versions to get thru the dry run // migration, we'll only exit the second time here once the // remote instance has had a time to migrate as well. case err == channeldb.ErrDryRunMigrationOK: ltndLog.Infof("Local DB dry run migration successful") case err != nil: err := fmt.Errorf("unable to open local channeldb: %v", err) ltndLog.Error(err) return nil, nil, nil, err } closeFuncs = append(closeFuncs, func() { localChanDB.Close() }) ltndLog.Infof("Opening replicated database instance...") remoteChanDB, err = channeldb.CreateWithBackend( databaseBackends.RemoteDB, channeldb.OptionDryRunMigration(cfg.DryRunMigration), channeldb.OptionSetBatchCommitInterval(cfg.DB.BatchCommitInterval), ) switch { case err == channeldb.ErrDryRunMigrationOK: return nil, nil, nil, err case err != nil: localChanDB.Close() err := fmt.Errorf("unable to open remote channeldb: %v", err) ltndLog.Error(err) return nil, nil, nil, err } closeFuncs = append(closeFuncs, func() { remoteChanDB.Close() }) } openTime := time.Since(startOpenTime) ltndLog.Infof("Database now open (time_to_open=%v)!", openTime) cleanUp := func() { for _, closeFunc := range closeFuncs { closeFunc() } } return localChanDB, remoteChanDB, cleanUp, nil } // initNeutrinoBackend inits a new instance of the neutrino light client // backend given a target chain directory to store the chain state. func initNeutrinoBackend(cfg *Config, chainDir string) (*neutrino.ChainService, func(), error) { // First we'll open the database file for neutrino, creating the // database if needed. We append the normalized network name here to // match the behavior of btcwallet. dbPath := filepath.Join( chainDir, lncfg.NormalizeNetwork(cfg.ActiveNetParams.Name), ) // Ensure that the neutrino db path exists. if err := os.MkdirAll(dbPath, 0700); err != nil { return nil, nil, err } dbName := filepath.Join(dbPath, "neutrino.db") db, err := walletdb.Create( "bdb", dbName, !cfg.SyncFreelist, cfg.DB.Bolt.DBTimeout, ) if err != nil { return nil, nil, fmt.Errorf("unable to create neutrino "+ "database: %v", err) } headerStateAssertion, err := parseHeaderStateAssertion( cfg.NeutrinoMode.AssertFilterHeader, ) if err != nil { db.Close() return nil, nil, err } // With the database open, we can now create an instance of the // neutrino light client. We pass in relevant configuration parameters // required. config := neutrino.Config{ DataDir: dbPath, Database: db, ChainParams: *cfg.ActiveNetParams.Params, AddPeers: cfg.NeutrinoMode.AddPeers, ConnectPeers: cfg.NeutrinoMode.ConnectPeers, Dialer: func(addr net.Addr) (net.Conn, error) { dialAddr := addr if tor.IsOnionFakeIP(addr) { // Because the Neutrino address manager only // knows IP addresses, we need to turn any fake // tcp6 address that actually encodes an Onion // v2 address back into the hostname // representation before we can pass it to the // dialer. var err error dialAddr, err = tor.FakeIPToOnionHost(addr) if err != nil { return nil, err } } return cfg.net.Dial( dialAddr.Network(), dialAddr.String(), cfg.ConnectionTimeout, ) }, NameResolver: func(host string) ([]net.IP, error) { if tor.IsOnionHost(host) { // Neutrino internally uses btcd's address // manager which only operates on an IP level // and does not understand onion hosts. We need // to turn an onion host into a fake // representation of an IP address to make it // possible to connect to a block filter backend // that serves on an Onion v2 hidden service. fakeIP, err := tor.OnionHostToFakeIP(host) if err != nil { return nil, err } return []net.IP{fakeIP}, nil } addrs, err := cfg.net.LookupHost(host) if err != nil { return nil, err } ips := make([]net.IP, 0, len(addrs)) for _, strIP := range addrs { ip := net.ParseIP(strIP) if ip == nil { continue } ips = append(ips, ip) } return ips, nil }, AssertFilterHeader: headerStateAssertion, } neutrino.MaxPeers = 8 neutrino.BanDuration = time.Hour * 48 neutrino.UserAgentName = cfg.NeutrinoMode.UserAgentName neutrino.UserAgentVersion = cfg.NeutrinoMode.UserAgentVersion neutrinoCS, err := neutrino.NewChainService(config) if err != nil { db.Close() return nil, nil, fmt.Errorf("unable to create neutrino light "+ "client: %v", err) } if err := neutrinoCS.Start(); err != nil { db.Close() return nil, nil, err } cleanUp := func() { if err := neutrinoCS.Stop(); err != nil { ltndLog.Infof("Unable to stop neutrino light client: %v", err) } db.Close() } return neutrinoCS, cleanUp, nil } // parseHeaderStateAssertion parses the user-specified neutrino header state // into a headerfs.FilterHeader. func parseHeaderStateAssertion(state string) (*headerfs.FilterHeader, error) { if len(state) == 0 { return nil, nil } split := strings.Split(state, ":") if len(split) != 2 { return nil, fmt.Errorf("header state assertion %v in "+ "unexpected format, expected format height:hash", state) } height, err := strconv.ParseUint(split[0], 10, 32) if err != nil { return nil, fmt.Errorf("invalid filter header height: %v", err) } hash, err := chainhash.NewHashFromStr(split[1]) if err != nil { return nil, fmt.Errorf("invalid filter header hash: %v", err) } return &headerfs.FilterHeader{ Height: uint32(height), FilterHash: *hash, }, nil }