package main import ( "encoding/hex" "fmt" "io/ioutil" "os" "path/filepath" "strings" "sync" "time" "github.com/lightninglabs/neutrino" "github.com/lightningnetwork/lnd/chainntnfs" "github.com/lightningnetwork/lnd/chainntnfs/btcdnotify" "github.com/lightningnetwork/lnd/chainntnfs/neutrinonotify" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/htlcswitch" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwallet/btcwallet" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/routing/chainview" "github.com/roasbeef/btcd/chaincfg/chainhash" "github.com/roasbeef/btcd/rpcclient" "github.com/roasbeef/btcutil" "github.com/roasbeef/btcwallet/chain" "github.com/roasbeef/btcwallet/walletdb" ) // defaultBitcoinForwardingPolicy is the default forwarding policy used for // Bitcoin channels. var defaultBitcoinForwardingPolicy = htlcswitch.ForwardingPolicy{ MinHTLC: lnwire.NewMSatFromSatoshis(1), BaseFee: lnwire.NewMSatFromSatoshis(1), FeeRate: 1, TimeLockDelta: 144, } // defaultLitecoinForwardingPolicy is the default forwarding policy used for // Litecoin channels. var defaultLitecoinForwardingPolicy = htlcswitch.ForwardingPolicy{ MinHTLC: lnwire.NewMSatFromSatoshis(1), BaseFee: 1, FeeRate: 1, TimeLockDelta: 576, } // defaultChannelConstraints is the default set of channel constraints that are // meant to be used when initially funding a channel. // // TODO(roasbeef): have one for both chains var defaultChannelConstraints = channeldb.ChannelConstraints{ DustLimit: lnwallet.DefaultDustLimit(), MaxAcceptedHtlcs: lnwallet.MaxHTLCNumber / 2, } // chainCode is an enum-like structure for keeping track of the chains // currently supported within lnd. type chainCode uint32 const ( // bitcoinChain is Bitcoin's testnet chain. bitcoinChain chainCode = iota // litecoinChain is Litecoin's testnet chain. litecoinChain ) // String returns a string representation of the target chainCode. func (c chainCode) String() string { switch c { case bitcoinChain: return "bitcoin" case litecoinChain: return "litecoin" default: return "kekcoin" } } // chainControl couples the three primary interfaces lnd utilizes for a // particular chain together. A single chainControl instance will exist for all // the chains lnd is currently active on. type chainControl struct { chainIO lnwallet.BlockChainIO feeEstimator lnwallet.FeeEstimator signer lnwallet.Signer msgSigner lnwallet.MessageSigner chainNotifier chainntnfs.ChainNotifier chainView chainview.FilteredChainView wallet *lnwallet.LightningWallet routingPolicy htlcswitch.ForwardingPolicy } // newChainControlFromConfig attempts to create a chainControl instance // according to the parameters in the passed lnd configuration. Currently two // branches of chainControl instances exist: one backed by a running btcd // full-node, and the other backed by a running neutrino light client instance. func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB, privateWalletPw, publicWalletPw []byte) (*chainControl, func(), error) { // Set the RPC config from the "home" chain. Multi-chain isn't yet // active, so we'll restrict usage to a particular chain for now. homeChainConfig := cfg.Bitcoin if registeredChains.PrimaryChain() == litecoinChain { homeChainConfig = cfg.Litecoin } ltndLog.Infof("Primary chain is set to: %v", registeredChains.PrimaryChain()) cc := &chainControl{} switch registeredChains.PrimaryChain() { case bitcoinChain: cc.routingPolicy = defaultBitcoinForwardingPolicy cc.feeEstimator = lnwallet.StaticFeeEstimator{ FeeRate: 50, } case litecoinChain: cc.routingPolicy = defaultLitecoinForwardingPolicy cc.feeEstimator = lnwallet.StaticFeeEstimator{ FeeRate: 100, } default: return nil, nil, fmt.Errorf("Default routing policy for "+ "chain %v is unknown", registeredChains.PrimaryChain()) } walletConfig := &btcwallet.Config{ PrivatePass: privateWalletPw, PublicPass: publicWalletPw, DataDir: homeChainConfig.ChainDir, NetParams: activeNetParams.Params, FeeEstimator: cc.feeEstimator, } var ( err error cleanUp func() ) // If spv mode is active, then we'll be using a distinct set of // chainControl interfaces that interface directly with the p2p network // of the selected chain. if cfg.NeutrinoMode.Active { // First we'll open the database file for neutrino, creating // the database if needed. dbName := filepath.Join(cfg.DataDir, "neutrino.db") nodeDatabase, err := walletdb.Create("bdb", dbName) if err != nil { 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: cfg.DataDir, Database: nodeDatabase, ChainParams: *activeNetParams.Params, AddPeers: cfg.NeutrinoMode.AddPeers, ConnectPeers: cfg.NeutrinoMode.ConnectPeers, } neutrino.WaitForMoreCFHeaders = time.Second * 1 neutrino.MaxPeers = 8 neutrino.BanDuration = 5 * time.Second svc, err := neutrino.NewChainService(config) if err != nil { return nil, nil, fmt.Errorf("unable to create neutrino: %v", err) } svc.Start() // Next we'll create the instances of the ChainNotifier and // FilteredChainView interface which is backed by the neutrino // light client. cc.chainNotifier, err = neutrinonotify.New(svc) if err != nil { return nil, nil, err } cc.chainView, err = chainview.NewCfFilteredChainView(svc) if err != nil { return nil, nil, err } // Finally, we'll set the chain source for btcwallet, and // create our clean up function which simply closes the // database. walletConfig.ChainSource = chain.NewNeutrinoClient(svc) cleanUp = func() { defer nodeDatabase.Close() } } else { // Otherwise, we'll be speaking directly via RPC to a node. // // So first we'll load btcd/ltcd's TLS cert for the RPC // connection. If a raw cert was specified in the config, then // we'll set that directly. Otherwise, we attempt to read the // cert from the path specified in the config. var rpcCert []byte if homeChainConfig.RawRPCCert != "" { rpcCert, err = hex.DecodeString(homeChainConfig.RawRPCCert) if err != nil { return nil, nil, err } } else { certFile, err := os.Open(homeChainConfig.RPCCert) if err != nil { return nil, nil, err } rpcCert, err = ioutil.ReadAll(certFile) if err != nil { return nil, nil, err } if err := certFile.Close(); err != nil { return nil, nil, err } } // If the specified host for the btcd/ltcd RPC server already // has a port specified, then we use that directly. Otherwise, // we assume the default port according to the selected chain // parameters. var btcdHost string if strings.Contains(homeChainConfig.RPCHost, ":") { btcdHost = homeChainConfig.RPCHost } else { btcdHost = fmt.Sprintf("%v:%v", homeChainConfig.RPCHost, activeNetParams.rpcPort) } btcdUser := homeChainConfig.RPCUser btcdPass := homeChainConfig.RPCPass rpcConfig := &rpcclient.ConnConfig{ Host: btcdHost, Endpoint: "ws", User: btcdUser, Pass: btcdPass, Certificates: rpcCert, DisableTLS: false, DisableConnectOnNew: true, DisableAutoReconnect: false, } cc.chainNotifier, err = btcdnotify.New(rpcConfig) if err != nil { return nil, nil, err } // Finally, we'll create an instance of the default chain view to be // used within the routing layer. cc.chainView, err = chainview.NewBtcdFilteredChainView(*rpcConfig) if err != nil { srvrLog.Errorf("unable to create chain view: %v", err) return nil, nil, err } // Create a special websockets rpc client for btcd which will be used // by the wallet for notifications, calls, etc. chainRPC, err := chain.NewRPCClient(activeNetParams.Params, btcdHost, btcdUser, btcdPass, rpcCert, false, 20) if err != nil { return nil, nil, err } walletConfig.ChainSource = chainRPC // If we're not in simnet or regtest mode, then we'll attempt // to use a proper fee estimator for testnet. if !cfg.Bitcoin.SimNet && !cfg.Litecoin.SimNet && !cfg.Bitcoin.RegTest && !cfg.Litecoin.RegTest { ltndLog.Infof("Initializing btcd backed fee estimator") // Finally, we'll re-initialize the fee estimator, as // if we're using btcd as a backend, then we can use // live fee estimates, rather than a statically coded // value. fallBackFeeRate := btcutil.Amount(25) cc.feeEstimator, err = lnwallet.NewBtcdFeeEstimator( *rpcConfig, fallBackFeeRate, ) if err != nil { return nil, nil, err } if err := cc.feeEstimator.Start(); err != nil { return nil, nil, err } } } wc, err := btcwallet.New(*walletConfig) if err != nil { fmt.Printf("unable to create wallet controller: %v\n", err) return nil, nil, err } cc.msgSigner = wc cc.signer = wc cc.chainIO = wc // Create, and start the lnwallet, which handles the core payment // channel logic, and exposes control via proxy state machines. walletCfg := lnwallet.Config{ Database: chanDB, Notifier: cc.chainNotifier, WalletController: wc, Signer: cc.signer, FeeEstimator: cc.feeEstimator, ChainIO: cc.chainIO, DefaultConstraints: defaultChannelConstraints, NetParams: *activeNetParams.Params, } wallet, err := lnwallet.NewLightningWallet(walletCfg) if err != nil { fmt.Printf("unable to create wallet: %v\n", err) return nil, nil, err } if err := wallet.Startup(); err != nil { fmt.Printf("unable to start wallet: %v\n", err) return nil, nil, err } ltndLog.Info("LightningWallet opened") cc.wallet = wallet return cc, cleanUp, nil } var ( // bitcoinGenesis is the genesis hash of Bitcoin's testnet chain. bitcoinGenesis = chainhash.Hash([chainhash.HashSize]byte{ 0x43, 0x49, 0x7f, 0xd7, 0xf8, 0x26, 0x95, 0x71, 0x08, 0xf4, 0xa3, 0x0f, 0xd9, 0xce, 0xc3, 0xae, 0xba, 0x79, 0x97, 0x20, 0x84, 0xe9, 0x0e, 0xad, 0x01, 0xea, 0x33, 0x09, 0x00, 0x00, 0x00, 0x00, }) // litecoinGenesis is the genesis hash of Litecoin's testnet4 chain. litecoinGenesis = chainhash.Hash([chainhash.HashSize]byte{ 0xa0, 0x29, 0x3e, 0x4e, 0xeb, 0x3d, 0xa6, 0xe6, 0xf5, 0x6f, 0x81, 0xed, 0x59, 0x5f, 0x57, 0x88, 0x0d, 0x1a, 0x21, 0x56, 0x9e, 0x13, 0xee, 0xfd, 0xd9, 0x51, 0x28, 0x4b, 0x5a, 0x62, 0x66, 0x49, }) // chainMap is a simple index that maps a chain's genesis hash to the // chainCode enum for that chain. chainMap = map[chainhash.Hash]chainCode{ bitcoinGenesis: bitcoinChain, litecoinGenesis: litecoinChain, } // reverseChainMap is the inverse of the chainMap above: it maps the // chain enum for a chain to its genesis hash. reverseChainMap = map[chainCode]chainhash.Hash{ bitcoinChain: bitcoinGenesis, litecoinChain: litecoinGenesis, } // chainDNSSeeds is a map of a chain's hash to the set of DNS seeds // that will be use to bootstrap peers upon first startup. // // The first item in the array is the primary host we'll use to attempt // the SRV lookup we require. If we're unable to receive a response // over UDP, then we'll fall back to manual TCP resolution. The second // item in the array is a special A record that we'll query in order to // receive the IP address of the current authoritative DNS server for // the network seed. // // TODO(roasbeef): extend and collapse these and chainparams.go into // struct like chaincfg.Params chainDNSSeeds = map[chainhash.Hash][][2]string{ bitcoinGenesis: { { "nodes.lightning.directory", "soa.nodes.lightning.directory", }, }, } ) // chainRegistry keeps track of the current chains type chainRegistry struct { sync.RWMutex activeChains map[chainCode]*chainControl netParams map[chainCode]*bitcoinNetParams primaryChain chainCode } // newChainRegistry creates a new chainRegistry. func newChainRegistry() *chainRegistry { return &chainRegistry{ activeChains: make(map[chainCode]*chainControl), netParams: make(map[chainCode]*bitcoinNetParams), } } // RegisterChain assigns an active chainControl instance to a target chain // identified by its chainCode. func (c *chainRegistry) RegisterChain(newChain chainCode, cc *chainControl) { c.Lock() c.activeChains[newChain] = cc c.Unlock() } // LookupChain attempts to lookup an active chainControl instance for the // target chain. func (c *chainRegistry) LookupChain(targetChain chainCode) (*chainControl, bool) { c.RLock() cc, ok := c.activeChains[targetChain] c.RUnlock() return cc, ok } // LookupChainByHash attempts to look up an active chainControl which // corresponds to the passed genesis hash. func (c *chainRegistry) LookupChainByHash(chainHash chainhash.Hash) (*chainControl, bool) { c.RLock() defer c.RUnlock() targetChain, ok := chainMap[chainHash] if !ok { return nil, ok } cc, ok := c.activeChains[targetChain] return cc, ok } // RegisterPrimaryChain sets a target chain as the "home chain" for lnd. func (c *chainRegistry) RegisterPrimaryChain(cc chainCode) { c.Lock() defer c.Unlock() c.primaryChain = cc } // PrimaryChain returns the primary chain for this running lnd instance. The // primary chain is considered the "home base" while the other registered // chains are treated as secondary chains. func (c *chainRegistry) PrimaryChain() chainCode { c.RLock() defer c.RUnlock() return c.primaryChain } // ActiveChains returns the total number of active chains. func (c *chainRegistry) ActiveChains() []chainCode { c.RLock() defer c.RUnlock() chains := make([]chainCode, 0, len(c.activeChains)) for activeChain := range c.activeChains { chains = append(chains, activeChain) } return chains } // NumActiveChains returns the total number of active chains. func (c *chainRegistry) NumActiveChains() uint32 { c.RLock() defer c.RUnlock() return uint32(len(c.activeChains)) }