lnd.xprv/pilot.go
2020-03-11 12:56:16 +01:00

278 lines
8.0 KiB
Go

package lnd
import (
"errors"
"fmt"
"net"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/autopilot"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/tor"
)
// validateAtplConfig is a helper method that makes sure the passed
// configuration is sane. Currently it checks that the heuristic configuration
// makes sense. In case the config is valid, it will return a list of
// WeightedHeuristics that can be combined for use with the autopilot agent.
func validateAtplCfg(cfg *autoPilotConfig) ([]*autopilot.WeightedHeuristic,
error) {
var (
heuristicsStr string
sum float64
heuristics []*autopilot.WeightedHeuristic
)
// Create a help text that we can return in case the config is not
// correct.
for _, a := range autopilot.AvailableHeuristics {
heuristicsStr += fmt.Sprintf(" '%v' ", a.Name())
}
availStr := fmt.Sprintf("Available heuristics are: [%v]", heuristicsStr)
// We'll go through the config and make sure all the heuristics exists,
// and that the sum of their weights is 1.0.
for name, weight := range cfg.Heuristic {
a, ok := autopilot.AvailableHeuristics[name]
if !ok {
// No heuristic matching this config option was found.
return nil, fmt.Errorf("Heuristic %v not available. %v",
name, availStr)
}
// If this heuristic was among the registered ones, we add it
// to the list we'll give to the agent, and keep track of the
// sum of weights.
heuristics = append(
heuristics,
&autopilot.WeightedHeuristic{
Weight: weight,
AttachmentHeuristic: a,
},
)
sum += weight
}
// Check found heuristics. We must have at least one to operate.
if len(heuristics) == 0 {
return nil, fmt.Errorf("No active heuristics. %v", availStr)
}
if sum != 1.0 {
return nil, fmt.Errorf("Heuristic weights must sum to 1.0")
}
return heuristics, nil
}
// 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
confTarget uint32
chanMinHtlcIn lnwire.MilliSatoshi
}
// 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(
c.confTarget,
)
if err != nil {
return err
}
// Construct the open channel request and send it to the server to begin
// the funding workflow.
req := &openChanReq{
targetPubkey: target,
chainHash: *activeNetParams.GenesisHash,
subtractFees: true,
localFundingAmt: amt,
pushAmt: 0,
minHtlcIn: c.chanMinHtlcIn,
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 structs. 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, chainCfg *chainConfig) (
*autopilot.ManagerCfg, error) {
atplLog.Infof("Instantiating autopilot with active=%v, "+
"max_channels=%d, allocation=%f, min_chan_size=%d, "+
"max_chan_size=%d, private=%t, min_confs=%d, conf_target=%d",
cfg.Active, cfg.MaxChannels, cfg.Allocation, cfg.MinChannelSize,
cfg.MaxChannelSize, cfg.Private, cfg.MinConfs, cfg.ConfTarget)
// 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,
)
heuristics, err := validateAtplCfg(cfg)
if err != nil {
return nil, err
}
weightedAttachment, err := autopilot.NewWeightedCombAttachment(
heuristics...,
)
if err != nil {
return nil, err
}
// 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: weightedAttachment,
ChanController: &chanController{
server: svr,
private: cfg.Private,
minConfs: cfg.MinConfs,
confTarget: cfg.ConfTarget,
chanMinHtlcIn: chainCfg.MinHTLCIn,
},
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,
}, nil
}