lnd.xprv/server.go

839 lines
23 KiB
Go

package main
import (
"encoding/hex"
"errors"
"fmt"
"net"
"sync"
"sync/atomic"
"time"
"github.com/btcsuite/fastsha256"
"github.com/lightningnetwork/lightning-onion"
"github.com/lightningnetwork/lnd/brontide"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/routing"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/chaincfg/chainhash"
"github.com/roasbeef/btcd/connmgr"
"github.com/roasbeef/btcutil"
)
// server is the main server of the Lightning Network Daemon. The server houses
// global state pertaining to the wallet, database, and the rpcserver.
// Additionally, the server is also used as a central messaging bus to interact
// with any of its companion objects.
type server struct {
started int32 // atomic
shutdown int32 // atomic
// identityPriv is the private key used to authenticate any incoming
// connections.
identityPriv *btcec.PrivateKey
// lightningID is the sha256 of the public key corresponding to our
// long-term identity private key.
lightningID [32]byte
peersMtx sync.RWMutex
peersByID map[int32]*peer
peersByPub map[string]*peer
rpcServer *rpcServer
chainNotifier chainntnfs.ChainNotifier
bio lnwallet.BlockChainIO
lnwallet *lnwallet.LightningWallet
fundingMgr *fundingManager
chanDB *channeldb.DB
htlcSwitch *htlcSwitch
invoices *invoiceRegistry
breachArbiter *breachArbiter
chanRouter *routing.ChannelRouter
utxoNursery *utxoNursery
sphinx *sphinx.Router
connMgr *connmgr.ConnManager
pendingConnMtx sync.RWMutex
persistentConnReqs map[string]*connmgr.ConnReq
broadcastRequests chan *broadcastReq
sendRequests chan *sendReq
newPeers chan *peer
donePeers chan *peer
queries chan interface{}
wg sync.WaitGroup
quit chan struct{}
}
// newServer creates a new instance of the server which is to listen using the
// passed listener address.
func newServer(listenAddrs []string, notifier chainntnfs.ChainNotifier,
bio lnwallet.BlockChainIO, wallet *lnwallet.LightningWallet,
chanDB *channeldb.DB) (*server, error) {
privKey, err := wallet.GetIdentitykey()
if err != nil {
return nil, err
}
privKey.Curve = btcec.S256()
listeners := make([]net.Listener, len(listenAddrs))
for i, addr := range listenAddrs {
listeners[i], err = brontide.NewListener(privKey, addr)
if err != nil {
return nil, err
}
}
serializedPubKey := privKey.PubKey().SerializeCompressed()
s := &server{
lnwallet: wallet,
bio: bio,
chainNotifier: notifier,
chanDB: chanDB,
invoices: newInvoiceRegistry(chanDB),
utxoNursery: newUtxoNursery(chanDB, notifier, wallet),
htlcSwitch: newHtlcSwitch(),
identityPriv: privKey,
// TODO(roasbeef): derive proper onion key based on rotation
// schedule
sphinx: sphinx.NewRouter(privKey, activeNetParams.Params),
lightningID: fastsha256.Sum256(serializedPubKey),
persistentConnReqs: make(map[string]*connmgr.ConnReq),
peersByID: make(map[int32]*peer),
peersByPub: make(map[string]*peer),
newPeers: make(chan *peer, 10),
donePeers: make(chan *peer, 10),
broadcastRequests: make(chan *broadcastReq),
sendRequests: make(chan *sendReq),
queries: make(chan interface{}),
quit: make(chan struct{}),
}
// If the debug HTLC flag is on, then we invoice a "master debug"
// invoice which all outgoing payments will be sent and all incoming
// HTLCs with the debug R-Hash immediately settled.
if cfg.DebugHTLC {
kiloCoin := btcutil.Amount(btcutil.SatoshiPerBitcoin * 1000)
s.invoices.AddDebugInvoice(kiloCoin, *debugPre)
srvrLog.Debugf("Debug HTLC invoice inserted, preimage=%x, hash=%x",
debugPre[:], debugHash[:])
}
// TODO(roasbeef): add --externalip flag?
selfAddr, ok := listeners[0].Addr().(*net.TCPAddr)
if !ok {
return nil, fmt.Errorf("default listener must be TCP")
}
chanGraph := chanDB.ChannelGraph()
self := &channeldb.LightningNode{
LastUpdate: time.Now(),
Address: selfAddr,
PubKey: privKey.PubKey(),
// TODO(roasbeef): make alias configurable
Alias: hex.EncodeToString(serializedPubKey[:10]),
}
if err := chanGraph.SetSourceNode(self); err != nil {
return nil, err
}
s.chanRouter, err = routing.New(routing.Config{
Graph: chanGraph,
Chain: bio,
Notifier: notifier,
Broadcast: s.broadcastMessage,
SendMessages: s.sendToPeer,
SendToSwitch: func(firstHop *btcec.PublicKey,
htlcAdd *lnwire.HTLCAddRequest) error {
firstHopPub := firstHop.SerializeCompressed()
destInterface := chainhash.Hash(fastsha256.Sum256(firstHopPub))
return s.htlcSwitch.SendHTLC(&htlcPacket{
dest: destInterface,
msg: htlcAdd,
})
},
})
if err != nil {
return nil, err
}
s.rpcServer = newRpcServer(s)
s.breachArbiter = newBreachArbiter(wallet, chanDB, notifier, s.htlcSwitch)
s.fundingMgr = newFundingManager(wallet, s.breachArbiter)
// TODO(roasbeef): introduce closure and config system to decouple the
// initialization above ^
// Create the connection manager which will be responsible for
// maintaining persistent outbound connections and also accepting new
// incoming connections
cmgr, err := connmgr.New(&connmgr.Config{
Listeners: listeners,
OnAccept: s.inboundPeerConnected,
RetryDuration: time.Second * 5,
TargetOutbound: 100,
GetNewAddress: nil,
Dial: noiseDial(s.identityPriv),
OnConnection: s.outboundPeerConnected,
})
if err != nil {
return nil, err
}
s.connMgr = cmgr
// In order to promote liveness of our active channels, instruct the
// connection manager to attempt to establish and maintain persistent
// connections to all our direct channel counterparties.
linkNodes, err := s.chanDB.FetchAllLinkNodes()
if err != nil && err != channeldb.ErrLinkNodesNotFound {
return nil, err
}
for _, node := range linkNodes {
// Create a wrapper address which couples the IP and the pubkey
// so the brontide authenticated connection can be established.
lnAddr := &lnwire.NetAddress{
IdentityKey: node.IdentityPub,
Address: node.Addresses[0],
}
pubStr := string(node.IdentityPub.SerializeCompressed())
srvrLog.Debugf("Attempting persistent connection to channel "+
"peer %v", lnAddr)
// Send the persistent connection request to the connection
// manager, saving the request itself so we can cancel/restart
// the process as needed.
// TODO(roasbeef): use default addr
connReq := &connmgr.ConnReq{
Addr: lnAddr,
Permanent: true,
}
s.persistentConnReqs[pubStr] = connReq
go s.connMgr.Connect(connReq)
}
return s, nil
}
// Start starts the main daemon server, all requested listeners, and any helper
// goroutines.
func (s *server) Start() error {
// Already running?
if atomic.AddInt32(&s.started, 1) != 1 {
return nil
}
// Start the notification server. This is used so channel management
// goroutines can be notified when a funding transaction reaches a
// sufficient number of confirmations, or when the input for the
// funding transaction is spent in an attempt at an uncooperative close
// by the counterparty.
if err := s.chainNotifier.Start(); err != nil {
return err
}
if err := s.rpcServer.Start(); err != nil {
return err
}
if err := s.fundingMgr.Start(); err != nil {
return err
}
if err := s.htlcSwitch.Start(); err != nil {
return err
}
if err := s.utxoNursery.Start(); err != nil {
return err
}
if err := s.breachArbiter.Start(); err != nil {
return err
}
if err := s.chanRouter.Start(); err != nil {
return err
}
s.wg.Add(1)
go s.queryHandler()
return nil
}
// Stop gracefully shutsdown the main daemon server. This function will signal
// any active goroutines, or helper objects to exit, then blocks until they've
// all successfully exited. Additionally, any/all listeners are closed.
func (s *server) Stop() error {
// Bail if we're already shutting down.
if atomic.AddInt32(&s.shutdown, 1) != 1 {
return nil
}
// Shutdown the wallet, funding manager, and the rpc server.
s.chainNotifier.Stop()
s.rpcServer.Stop()
s.fundingMgr.Stop()
s.chanRouter.Stop()
s.htlcSwitch.Stop()
s.utxoNursery.Stop()
s.breachArbiter.Stop()
s.lnwallet.Shutdown()
// Signal all the lingering goroutines to quit.
close(s.quit)
s.wg.Wait()
return nil
}
// WaitForShutdown blocks all goroutines have been stopped.
func (s *server) WaitForShutdown() {
s.wg.Wait()
}
// broadcastReq is a message sent to the server by a related subsystem when it
// wishes to broadcast one or more messages to all connected peers. Thi
type broadcastReq struct {
ignore *btcec.PublicKey
msgs []lnwire.Message
errChan chan error // MUST be buffered.
}
// broadcastMessage sends a request to the server to broadcast a set of
// messages to all peers other than the one specified by the `skip` parameter.
func (s *server) broadcastMessage(skip *btcec.PublicKey, msgs ...lnwire.Message) error {
errChan := make(chan error, 1)
msgsToSend := make([]lnwire.Message, 0, len(msgs))
msgsToSend = append(msgsToSend, msgs...)
broadcastReq := &broadcastReq{
ignore: skip,
msgs: msgsToSend,
errChan: errChan,
}
select {
case s.broadcastRequests <- broadcastReq:
case <-s.quit:
return errors.New("server shutting down")
}
select {
case err := <-errChan:
return err
case <-s.quit:
return errors.New("server shutting down")
}
}
// sendReq is message sent to the server by a related subsystem which it
// wishes to send a set of messages to a specified peer.
type sendReq struct {
target *btcec.PublicKey
msgs []lnwire.Message
errChan chan error
}
// sendToPeer send a message to the server telling it to send the specific set
// of message to a particular peer. If the peer connect be found, then this
// method will return a non-nil error.
func (s *server) sendToPeer(target *btcec.PublicKey, msgs ...lnwire.Message) error {
errChan := make(chan error, 1)
msgsToSend := make([]lnwire.Message, 0, len(msgs))
msgsToSend = append(msgsToSend, msgs...)
sMsg := &sendReq{
target: target,
msgs: msgsToSend,
errChan: errChan,
}
select {
case s.sendRequests <- sMsg:
case <-s.quit:
return errors.New("server shutting down")
}
select {
case err := <-errChan:
return err
case <-s.quit:
return errors.New("server shutting down")
}
return nil
}
// peerConnected is a function that handles initialization a newly connected
// peer by adding it to the server's global list of all active peers, and
// starting all the goroutines the peer needs to function properly.
func (s *server) peerConnected(conn net.Conn, connReq *connmgr.ConnReq, inbound bool) {
brontideConn := conn.(*brontide.Conn)
peerAddr := &lnwire.NetAddress{
IdentityKey: brontideConn.RemotePub(),
Address: conn.RemoteAddr().(*net.TCPAddr),
ChainNet: activeNetParams.Net,
}
// Now that we've established a connection, create a peer, and
// it to the set of currently active peers.
peer, err := newPeer(conn, s, peerAddr, false)
if err != nil {
srvrLog.Errorf("unable to create peer %v", err)
conn.Close()
return
}
if connReq != nil {
peer.connReq = connReq
}
// TODO(roasbeef): update IP address for link-node
// * also mark last-seen, do it one single transaction?
peer.Start()
s.newPeers <- peer
}
// inboundPeerConnected initializes a new peer in response to a new inbound
// connection.
func (s *server) inboundPeerConnected(conn net.Conn) {
s.peersMtx.Lock()
defer s.peersMtx.Unlock()
srvrLog.Tracef("New inbound connection from %v", conn.RemoteAddr())
nodePub := conn.(*brontide.Conn).RemotePub()
// If we already have an outbound connection to this peer, simply drop
// the connection.
pubStr := string(nodePub.SerializeCompressed())
if _, ok := s.peersByPub[pubStr]; ok {
srvrLog.Errorf("Received inbound connection from peer %x, but "+
"already connected, dropping conn",
nodePub.SerializeCompressed())
conn.Close()
return
}
// However, if we receive an incoming connection from a peer we're
// attempting to maintain a persistent connection with then we need to
// cancel the ongoing connection attempts to ensure that we don't end
// up with a duplicate connecting to the same peer.
s.pendingConnMtx.RLock()
if connReq, ok := s.persistentConnReqs[pubStr]; ok {
s.connMgr.Remove(connReq.ID())
}
s.pendingConnMtx.RUnlock()
s.peerConnected(conn, nil, false)
}
// outboundPeerConnected initializes a new peer in response to a new outbound
// connection.
func (s *server) outboundPeerConnected(connReq *connmgr.ConnReq, conn net.Conn) {
s.peersMtx.Lock()
defer s.peersMtx.Unlock()
srvrLog.Tracef("Established connection to: %v", conn.RemoteAddr())
nodePub := conn.(*brontide.Conn).RemotePub()
// If we already have an inbound connection from this peer, simply drop
// the connection.
pubStr := string(nodePub.SerializeCompressed())
if _, ok := s.peersByPub[pubStr]; ok {
srvrLog.Errorf("Established outbound connection to peer %x, but "+
"already connected, dropping conn",
nodePub.SerializeCompressed())
s.connMgr.Remove(connReq.ID())
conn.Close()
return
}
s.peerConnected(conn, connReq, true)
}
// addPeer adds the passed peer to the server's global state of all active
// peers.
func (s *server) addPeer(p *peer) {
if p == nil {
return
}
// Ignore new peers if we're shutting down.
if atomic.LoadInt32(&s.shutdown) != 0 {
p.Stop()
return
}
// Track the new peer in our indexes so we can quickly look it up either
// according to its public key, or it's peer ID.
// TODO(roasbeef): pipe all requests through to the
// queryHandler/peerManager
s.peersMtx.Lock()
s.peersByID[p.id] = p
s.peersByPub[string(p.addr.IdentityKey.SerializeCompressed())] = p
s.peersMtx.Unlock()
// Once the peer has been added to our indexes, send a message to the
// channel router so we can synchronize our view of the channel graph
// with this new peer.
go s.chanRouter.SynchronizeNode(p.addr.IdentityKey)
}
// removePeer removes the passed peer from the server's state of all active
// peers.
func (s *server) removePeer(p *peer) {
s.peersMtx.Lock()
defer s.peersMtx.Unlock()
srvrLog.Debugf("removing peer %v", p)
if p == nil {
return
}
// As the peer is now finished, ensure that the TCP connection is
// closed and all of its related goroutines have exited.
if err := p.Stop(); err != nil {
peerLog.Errorf("unable to stop peer: %v", err)
}
// Ignore deleting peers if we're shutting down.
if atomic.LoadInt32(&s.shutdown) != 0 {
return
}
delete(s.peersByID, p.id)
delete(s.peersByPub, string(p.addr.IdentityKey.SerializeCompressed()))
}
// connectPeerMsg is a message requesting the server to open a connection to a
// particular peer. This message also houses an error channel which will be
// used to report success/failure.
type connectPeerMsg struct {
addr *lnwire.NetAddress
persistent bool
err chan error
}
// listPeersMsg is a message sent to the server in order to obtain a listing
// of all currently active channels.
type listPeersMsg struct {
resp chan []*peer
}
// openChanReq is a message sent to the server in order to request the
// initiation of a channel funding workflow to the peer with either the specified
// relative peer ID, or a global lightning ID.
type openChanReq struct {
targetPeerID int32
targetPubkey *btcec.PublicKey
// TODO(roasbeef): make enums in lnwire
channelType uint8
coinType uint64
localFundingAmt btcutil.Amount
remoteFundingAmt btcutil.Amount
pushAmt btcutil.Amount
numConfs uint32
updates chan *lnrpc.OpenStatusUpdate
err chan error
}
// queryHandler handles any requests to modify the server's internal state of
// all active peers, or query/mutate the server's global state. Additionally,
// any queries directed at peers will be handled by this goroutine.
//
// NOTE: This MUST be run as a goroutine.
func (s *server) queryHandler() {
go s.connMgr.Start()
out:
for {
select {
// New peers.
case p := <-s.newPeers:
s.addPeer(p)
// Finished peers.
case p := <-s.donePeers:
s.removePeer(p)
case bMsg := <-s.broadcastRequests:
ignore := bMsg.ignore
srvrLog.Debugf("Broadcasting %v messages", len(bMsg.msgs))
// Launch a new goroutine to handle the broadcast
// request, this allows us process this request
// asynchronously without blocking subsequent broadcast
// requests.
go func() {
s.peersMtx.RLock()
for _, sPeer := range s.peersByPub {
if ignore != nil &&
sPeer.addr.IdentityKey.IsEqual(ignore) {
srvrLog.Debugf("Skipping %v in broadcast",
ignore.SerializeCompressed())
continue
}
go func(p *peer) {
for _, msg := range bMsg.msgs {
p.queueMsg(msg, nil)
}
}(sPeer)
}
s.peersMtx.RUnlock()
bMsg.errChan <- nil
}()
case sMsg := <-s.sendRequests:
// TODO(roasbeef): use [33]byte everywhere instead
// * eliminate usage of mutexes, funnel all peer
// mutation to this goroutine
target := sMsg.target.SerializeCompressed()
srvrLog.Debugf("Attempting to send msgs %v to: %x",
len(sMsg.msgs), target)
// Launch a new goroutine to handle this send request,
// this allows us process this request asynchronously
// without blocking future send requests.
go func() {
s.peersMtx.RLock()
targetPeer, ok := s.peersByPub[string(target)]
if !ok {
s.peersMtx.RUnlock()
srvrLog.Errorf("unable to send message to %x, "+
"peer not found", target)
sMsg.errChan <- errors.New("peer not found")
return
}
s.peersMtx.RUnlock()
sMsg.errChan <- nil
for _, msg := range sMsg.msgs {
targetPeer.queueMsg(msg, nil)
}
}()
case query := <-s.queries:
switch msg := query.(type) {
case *connectPeerMsg:
s.handleConnectPeer(msg)
case *listPeersMsg:
s.handleListPeers(msg)
case *openChanReq:
s.handleOpenChanReq(msg)
}
case <-s.quit:
break out
}
}
s.connMgr.Stop()
s.wg.Done()
}
// handleListPeers sends a lice of all currently active peers to the original
// caller.
func (s *server) handleListPeers(msg *listPeersMsg) {
s.peersMtx.RLock()
peers := make([]*peer, 0, len(s.peersByID))
for _, peer := range s.peersByID {
peers = append(peers, peer)
}
s.peersMtx.RUnlock()
msg.resp <- peers
}
// handleConnectPeer attempts to establish a connection to the address enclosed
// within the passed connectPeerMsg. This function is *async*, a goroutine will
// be spawned in order to finish the request, and respond to the caller.
func (s *server) handleConnectPeer(msg *connectPeerMsg) {
addr := msg.addr
targetPub := string(msg.addr.IdentityKey.SerializeCompressed())
// Ensure we're not already connected to this
// peer.
s.peersMtx.RLock()
peer, ok := s.peersByPub[targetPub]
if ok {
s.peersMtx.RUnlock()
msg.err <- fmt.Errorf("already connected to peer: %v", peer)
return
}
s.peersMtx.RUnlock()
// If there's already a pending connection request for this pubkey,
// then we ignore this request to ensure we don't create a redundant
// connection.
s.pendingConnMtx.RLock()
if _, ok := s.persistentConnReqs[targetPub]; ok {
s.pendingConnMtx.RUnlock()
msg.err <- fmt.Errorf("connection attempt to %v is pending",
addr)
return
}
s.pendingConnMtx.RUnlock()
// If there's not already a pending or active connection to this node,
// then instruct the connection manager to attempt to establish a
// persistent connection to the peer.
srvrLog.Debugf("Connecting to %v", addr)
if msg.persistent {
go s.connMgr.Connect(&connmgr.ConnReq{
Addr: addr,
Permanent: true,
})
msg.err <- nil
} else {
// If we're not making a persistent connection, then we'll
// attempt to connect o the target peer, returning an error
// which indicates success of failure.
go func() {
// Attempt to connect to the remote node. If the we
// can't make the connection, or the crypto negotiation
// breaks down, then return an error to the caller.
conn, err := brontide.Dial(s.identityPriv, addr)
if err != nil {
msg.err <- err
return
}
s.outboundPeerConnected(nil, conn)
msg.err <- nil
}()
}
}
// handleOpenChanReq first locates the target peer, and if found hands off the
// request to the funding manager allowing it to initiate the channel funding
// workflow.
func (s *server) handleOpenChanReq(req *openChanReq) {
var (
targetPeer *peer
pubStr string
)
// If the user is targeting the peer by public key, then we'll need to
// convert that into a string for our map. Otherwise, we expect them to
// target by peer ID instead.
if req.targetPubkey != nil {
pubStr = string(req.targetPubkey.SerializeCompressed())
}
// First attempt to locate the target peer to open a channel with, if
// we're unable to locate the peer then this request will fail.
s.peersMtx.RLock()
if peer, ok := s.peersByID[req.targetPeerID]; ok {
targetPeer = peer
} else if peer, ok := s.peersByPub[pubStr]; ok {
targetPeer = peer
}
s.peersMtx.RUnlock()
if targetPeer == nil {
req.err <- fmt.Errorf("unable to find peer nodeID(%x), "+
"peerID(%v)", req.targetPubkey.SerializeCompressed(),
req.targetPeerID)
return
}
// Spawn a goroutine to send the funding workflow request to the funding
// manager. This allows the server to continue handling queries instead
// of blocking on this request which is exported as a synchronous
// request to the outside world.
// TODO(roasbeef): server semaphore to restrict num goroutines
go s.fundingMgr.initFundingWorkflow(targetPeer, req)
}
// ConnectToPeer requests that the server connect to a Lightning Network peer
// at the specified address. This function will *block* until either a
// connection is established, or the initial handshake process fails.
func (s *server) ConnectToPeer(addr *lnwire.NetAddress,
perm bool) error {
errChan := make(chan error, 1)
s.queries <- &connectPeerMsg{
addr: addr,
persistent: perm,
err: errChan,
}
return <-errChan
}
// OpenChannel sends a request to the server to open a channel to the specified
// peer identified by ID with the passed channel funding paramters.
func (s *server) OpenChannel(peerID int32, nodeKey *btcec.PublicKey,
localAmt, pushAmt btcutil.Amount,
numConfs uint32) (chan *lnrpc.OpenStatusUpdate, chan error) {
errChan := make(chan error, 1)
updateChan := make(chan *lnrpc.OpenStatusUpdate, 1)
req := &openChanReq{
targetPeerID: peerID,
targetPubkey: nodeKey,
localFundingAmt: localAmt,
pushAmt: pushAmt,
numConfs: numConfs,
updates: updateChan,
err: errChan,
}
s.queries <- req
return updateChan, errChan
}
// Peers returns a slice of all active peers.
func (s *server) Peers() []*peer {
resp := make(chan []*peer, 1)
s.queries <- &listPeersMsg{resp}
return <-resp
}