package main import ( "errors" "fmt" "net" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/wire" "github.com/btcsuite/btcutil" "github.com/davecgh/go-spew/spew" "github.com/lightningnetwork/lnd/autopilot" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/tor" ) // chanController is an implementation of the autopilot.ChannelController // interface that's backed by a running lnd instance. type chanController struct { server *server private bool minConfs int32 } // OpenChannel opens a channel to a target peer, with a capacity of the // specified amount. This function should un-block immediately after the // funding transaction that marks the channel open has been broadcast. func (c *chanController) OpenChannel(target *btcec.PublicKey, amt btcutil.Amount) error { // With the connection established, we'll now establish our connection // to the target peer, waiting for the first update before we exit. feePerKw, err := c.server.cc.feeEstimator.EstimateFeePerKW(3) if err != nil { return err } // TODO(halseth): make configurable? minHtlc := lnwire.NewMSatFromSatoshis(1) // Construct the open channel request and send it to the server to begin // the funding workflow. req := &openChanReq{ targetPubkey: target, chainHash: *activeNetParams.GenesisHash, localFundingAmt: amt, pushAmt: 0, minHtlc: minHtlc, fundingFeePerKw: feePerKw, private: c.private, remoteCsvDelay: 0, minConfs: c.minConfs, } updateStream, errChan := c.server.OpenChannel(req) select { case err := <-errChan: return err case <-updateStream: return nil case <-c.server.quit: return nil } } func (c *chanController) CloseChannel(chanPoint *wire.OutPoint) error { return nil } func (c *chanController) SpliceIn(chanPoint *wire.OutPoint, amt btcutil.Amount) (*autopilot.Channel, error) { return nil, nil } func (c *chanController) SpliceOut(chanPoint *wire.OutPoint, amt btcutil.Amount) (*autopilot.Channel, error) { return nil, nil } // A compile time assertion to ensure chanController meets the // autopilot.ChannelController interface. var _ autopilot.ChannelController = (*chanController)(nil) // initAutoPilot initializes a new autopilot.ManagerCfg to manage an // autopilot.Agent instance based on the passed configuration struct. The agent // and all interfaces needed to drive it won't be launched before the Manager's // StartAgent method is called. func initAutoPilot(svr *server, cfg *autoPilotConfig) *autopilot.ManagerCfg { atplLog.Infof("Instantiating autopilot with cfg: %v", spew.Sdump(cfg)) // Set up the constraints the autopilot heuristics must adhere to. atplConstraints := autopilot.NewConstraints( btcutil.Amount(cfg.MinChannelSize), btcutil.Amount(cfg.MaxChannelSize), uint16(cfg.MaxChannels), 10, cfg.Allocation, ) // First, we'll create the preferential attachment heuristic. prefAttachment := autopilot.NewPrefAttachment() // With the heuristic itself created, we can now populate the remainder // of the items that the autopilot agent needs to perform its duties. self := svr.identityPriv.PubKey() pilotCfg := autopilot.Config{ Self: self, Heuristic: prefAttachment, ChanController: &chanController{ server: svr, private: cfg.Private, minConfs: cfg.MinConfs, }, WalletBalance: func() (btcutil.Amount, error) { return svr.cc.wallet.ConfirmedBalance(cfg.MinConfs) }, Graph: autopilot.ChannelGraphFromDatabase(svr.chanDB.ChannelGraph()), Constraints: atplConstraints, ConnectToPeer: func(target *btcec.PublicKey, addrs []net.Addr) (bool, error) { // First, we'll check if we're already connected to the // target peer. If we are, we can exit early. Otherwise, // we'll need to establish a connection. if _, err := svr.FindPeer(target); err == nil { return true, nil } // We can't establish a channel if no addresses were // provided for the peer. if len(addrs) == 0 { return false, errors.New("no addresses specified") } atplLog.Tracef("Attempting to connect to %x", target.SerializeCompressed()) lnAddr := &lnwire.NetAddress{ IdentityKey: target, ChainNet: activeNetParams.Net, } // We'll attempt to successively connect to each of the // advertised IP addresses until we've either exhausted // the advertised IP addresses, or have made a // connection. var connected bool for _, addr := range addrs { switch addr.(type) { case *net.TCPAddr, *tor.OnionAddr: lnAddr.Address = addr default: return false, fmt.Errorf("unknown "+ "address type %T", addr) } err := svr.ConnectToPeer(lnAddr, false) if err != nil { // If we weren't able to connect to the // peer at this address, then we'll move // onto the next. continue } connected = true break } // If we weren't able to establish a connection at all, // then we'll error out. if !connected { return false, errors.New("exhausted all " + "advertised addresses") } return false, nil }, DisconnectPeer: svr.DisconnectPeer, } // Create and return the autopilot.ManagerCfg that administrates this // agent-pilot instance. return &autopilot.ManagerCfg{ Self: self, PilotCfg: &pilotCfg, ChannelState: func() ([]autopilot.Channel, error) { // We'll fetch the current state of open // channels from the database to use as initial // state for the auto-pilot agent. activeChannels, err := svr.chanDB.FetchAllChannels() if err != nil { return nil, err } chanState := make([]autopilot.Channel, len(activeChannels)) for i, channel := range activeChannels { chanState[i] = autopilot.Channel{ ChanID: channel.ShortChanID(), Capacity: channel.Capacity, Node: autopilot.NewNodeID( channel.IdentityPub), } } return chanState, nil }, SubscribeTransactions: svr.cc.wallet.SubscribeTransactions, SubscribeTopology: svr.chanRouter.SubscribeTopology, } }