// newPeer creates a new peer from an establish connection object, and a
// pointer to the main server.
func newPeer(conn net.Conn, server *server, addr *lnwire.NetAddress,
inbound bool) (*peer, error) {
nodePub := addr.IdentityKey
p := &peer{
conn: conn,
lightningID: wire.ShaHash(fastsha256.Sum256(nodePub.SerializeCompressed())),
addr: addr,
id: atomic.AddInt32(&numNodes, 1),
inbound: inbound,
server: server,
lastNMessages: make(map[lnwire.Message]struct{}),
sendQueueSync: make(chan struct{}, 1),
sendQueue: make(chan outgoinMsg, 1),
outgoingQueue: make(chan outgoinMsg, outgoingQueueLen),
barrierInits: make(chan wire.OutPoint),
newChanBarriers: make(map[wire.OutPoint]chan struct{}),
activeChannels: make(map[wire.OutPoint]*lnwallet.LightningChannel),
htlcManagers: make(map[wire.OutPoint]chan lnwire.Message),
chanSnapshotReqs: make(chan *chanSnapshotReq),
newChannels: make(chan *lnwallet.LightningChannel, 1),
localCloseChanReqs: make(chan *closeLinkReq),
remoteCloseChanReqs: make(chan *lnwire.CloseRequest),
queueQuit: make(chan struct{}),
quit: make(chan struct{}),
}
// Initiate the pending channel identifier properly depending on if this
// node is inbound or outbound. This value will be used in an increasing
// manner to track pending channels.
if inbound {
p.nextPendingChannelID = 1 << 63
} else {
p.nextPendingChannelID = 0
}
// Fetch and then load all the active channels we have with this
// remote peer from the database.
activeChans, err := server.chanDB.FetchOpenChannels(p.addr.IdentityKey)
if err != nil {
peerLog.Errorf("unable to fetch active chans "+
"for peer %v: %v", p, err)
return nil, err
}
peerLog.Debugf("Loaded %v active channels from database with peerID(%v)",
len(activeChans), p.id)
if err := p.loadActiveChannels(activeChans); err != nil {
return nil, err
}
return p, nil
}
// addDebugInvoice adds a debug invoice for the specified amount, identified
// by the passed preimage. Once this invoice is added, sub-systems within the
// daemon add/forward HTLC's are able to obtain the proper preimage required
// for redemption in the case that we're the final destination.
func (i *invoiceRegistry) AddDebugInvoice(amt btcutil.Amount, preimage wire.ShaHash) {
paymentHash := wire.ShaHash(fastsha256.Sum256(preimage[:]))
invoice := &channeldb.Invoice{
CreationDate: time.Now(),
Terms: channeldb.ContractTerm{
Value: amt,
PaymentPreimage: preimage,
},
}
i.Lock()
i.debugInvoices[paymentHash] = invoice
i.Unlock()
ltndLog.Debugf("Adding debug invoice %v", newLogClosure(func() string {
return spew.Sdump(invoice)
}))
}
// SendPayment dispatches a bi-directional streaming RPC for sending payments
// through the Lightning Network. A single RPC invocation creates a persistent
// bi-directional stream allowing clients to rapidly send payments through the
// Lightning Network with a single persistent connection.
func (r *rpcServer) SendPayment(paymentStream lnrpc.Lightning_SendPaymentServer) error {
const queryTimeout = time.Duration(time.Second * 10)
errChan := make(chan error, 1)
payChan := make(chan *lnrpc.SendRequest)
// Launch a new goroutine to handle reading new payment requests from
// the client. This way we can handle errors independently of blocking
// and waiting for the next payment request to come through.
go func() {
for {
select {
case <-r.quit:
errChan <- nil
return
default:
// Receive the next pending payment within the
// stream sent by the client. If we read the
// EOF sentinel, then the client has closed the
// stream, and we can exit normally.
nextPayment, err := paymentStream.Recv()
if err == io.EOF {
errChan <- nil
return
} else if err != nil {
errChan <- err
return
}
payChan <- nextPayment
}
}
}()
for {
select {
case err := <-errChan:
return err
case nextPayment := <-payChan:
// Query the routing table for a potential path to the
// destination node. If a path is ultimately
// unavailable, then an error will be returned.
destNode := hex.EncodeToString(nextPayment.Dest)
targetVertex := graph.NewID(destNode)
path, err := r.server.routingMgr.FindPath(targetVertex,
queryTimeout)
if err != nil {
return err
}
rpcsLog.Tracef("[sendpayment] selected route: %v", path)
// If we're in debug HTLC mode, then all outgoing
// HTLC's will pay to the same debug rHash. Otherwise,
// we pay to the rHash specified within the RPC
// request.
var rHash [32]byte
if cfg.DebugHTLC {
rHash = debugHash
} else {
copy(rHash[:], nextPayment.PaymentHash)
}
// Generate the raw encoded sphinx packet to be
// included along with the HTLC add message. We snip
// off the first hop from the path as within the
// routing table's star graph, we're always the first
// hop.
sphinxPacket, err := generateSphinxPacket(path[1:], rHash[:])
if err != nil {
return err
}
// Craft an HTLC packet to send to the routing
// sub-system. The meta-data within this packet will be
// used to route the payment through the network.
htlcAdd := &lnwire.HTLCAddRequest{
Amount: lnwire.CreditsAmount(nextPayment.Amt),
RedemptionHashes: [][32]byte{rHash},
OnionBlob: sphinxPacket,
}
firstHopPub, err := hex.DecodeString(path[1].String())
if err != nil {
return err
}
destAddr := wire.ShaHash(fastsha256.Sum256(firstHopPub))
htlcPkt := &htlcPacket{
dest: destAddr,
msg: htlcAdd,
}
// TODO(roasbeef): semaphore to limit num outstanding
// goroutines.
go func() {
// Finally, send this next packet to the
// routing layer in order to complete the next
// payment.
// TODO(roasbeef): this should go through the
// L3 router once multi-hop is in place.
if err := r.server.htlcSwitch.SendHTLC(htlcPkt); err != nil {
errChan <- err
return
}
// TODO(roasbeef): proper responses
resp := &lnrpc.SendResponse{}
if err := paymentStream.Send(resp); err != nil {
errChan <- err
return
}
}()
}
}
return nil
}
// createTestChannels creates two test channels funded witr 10 BTC, with 5 BTC
// allocated to each side.
func createTestChannels(revocationWindow int) (*LightningChannel, *LightningChannel, func(), error) {
aliceKeyPriv, aliceKeyPub := btcec.PrivKeyFromBytes(btcec.S256(),
testWalletPrivKey)
bobKeyPriv, bobKeyPub := btcec.PrivKeyFromBytes(btcec.S256(),
bobsPrivKey)
channelCapacity := btcutil.Amount(10 * 1e8)
channelBal := channelCapacity / 2
csvTimeoutAlice := uint32(5)
csvTimeoutBob := uint32(4)
witnessScript, _, err := GenFundingPkScript(aliceKeyPub.SerializeCompressed(),
bobKeyPub.SerializeCompressed(), int64(channelCapacity))
if err != nil {
return nil, nil, nil, err
}
prevOut := &wire.OutPoint{
Hash: wire.ShaHash(testHdSeed),
Index: 0,
}
fundingTxIn := wire.NewTxIn(prevOut, nil, nil)
bobElkrem := elkrem.NewElkremSender(deriveElkremRoot(bobKeyPriv, bobKeyPub, aliceKeyPub))
bobFirstRevoke, err := bobElkrem.AtIndex(0)
if err != nil {
return nil, nil, nil, err
}
bobRevokeKey := DeriveRevocationPubkey(aliceKeyPub, bobFirstRevoke[:])
aliceElkrem := elkrem.NewElkremSender(deriveElkremRoot(aliceKeyPriv, aliceKeyPub, bobKeyPub))
aliceFirstRevoke, err := aliceElkrem.AtIndex(0)
if err != nil {
return nil, nil, nil, err
}
aliceRevokeKey := DeriveRevocationPubkey(bobKeyPub, aliceFirstRevoke[:])
aliceCommitTx, err := CreateCommitTx(fundingTxIn, aliceKeyPub,
bobKeyPub, aliceRevokeKey, csvTimeoutAlice, channelBal, channelBal)
if err != nil {
return nil, nil, nil, err
}
bobCommitTx, err := CreateCommitTx(fundingTxIn, bobKeyPub,
aliceKeyPub, bobRevokeKey, csvTimeoutBob, channelBal, channelBal)
if err != nil {
return nil, nil, nil, err
}
alicePath, err := ioutil.TempDir("", "alicedb")
dbAlice, err := channeldb.Open(alicePath, &chaincfg.TestNet3Params)
if err != nil {
return nil, nil, nil, err
}
bobPath, err := ioutil.TempDir("", "bobdb")
dbBob, err := channeldb.Open(bobPath, &chaincfg.TestNet3Params)
if err != nil {
return nil, nil, nil, err
}
aliceChannelState := &channeldb.OpenChannel{
IdentityPub: aliceKeyPub,
ChanID: prevOut,
OurCommitKey: aliceKeyPub,
TheirCommitKey: bobKeyPub,
Capacity: channelCapacity,
OurBalance: channelBal,
TheirBalance: channelBal,
OurCommitTx: aliceCommitTx,
FundingOutpoint: prevOut,
OurMultiSigKey: aliceKeyPub,
TheirMultiSigKey: bobKeyPub,
FundingWitnessScript: witnessScript,
LocalCsvDelay: csvTimeoutAlice,
RemoteCsvDelay: csvTimeoutBob,
TheirCurrentRevocation: bobRevokeKey,
LocalElkrem: aliceElkrem,
RemoteElkrem: &elkrem.ElkremReceiver{},
Db: dbAlice,
}
bobChannelState := &channeldb.OpenChannel{
IdentityPub: bobKeyPub,
ChanID: prevOut,
OurCommitKey: bobKeyPub,
TheirCommitKey: aliceKeyPub,
Capacity: channelCapacity,
OurBalance: channelBal,
TheirBalance: channelBal,
OurCommitTx: bobCommitTx,
FundingOutpoint: prevOut,
OurMultiSigKey: bobKeyPub,
TheirMultiSigKey: aliceKeyPub,
FundingWitnessScript: witnessScript,
LocalCsvDelay: csvTimeoutBob,
RemoteCsvDelay: csvTimeoutAlice,
TheirCurrentRevocation: aliceRevokeKey,
LocalElkrem: bobElkrem,
RemoteElkrem: &elkrem.ElkremReceiver{},
Db: dbBob,
}
cleanUpFunc := func() {
os.RemoveAll(bobPath)
os.RemoveAll(alicePath)
}
aliceSigner := &mockSigner{aliceKeyPriv}
bobSigner := &mockSigner{bobKeyPriv}
notifier := &mockNotfier{}
channelAlice, err := NewLightningChannel(aliceSigner, nil, notifier, aliceChannelState)
if err != nil {
return nil, nil, nil, err
}
channelBob, err := NewLightningChannel(bobSigner, nil, notifier, bobChannelState)
if err != nil {
return nil, nil, nil, err
}
// Now that the channel are open, simulate the start of a session by
// having Alice and Bob extend their revocation windows to each other.
err = initRevocationWindows(channelAlice, channelBob, revocationWindow)
if err != nil {
return nil, nil, nil, err
}
return channelAlice, channelBob, cleanUpFunc, nil
}
"github.com/btcsuite/fastsha256"
"github.com/davecgh/go-spew/spew"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/roasbeef/btcd/wire"
"github.com/roasbeef/btcutil"
)
var (
// debugPre is the default debug preimage which is inserted into the
// invoice registry if the --debughtlc flag is activated on start up.
// All nodes initialize with the flag active will immediately settle
// any incoming HTLC whose rHash is corresponds with the debug
// preimage.
debugPre, _ = wire.NewShaHash(bytes.Repeat([]byte{1}, 32))
debugHash = wire.ShaHash(fastsha256.Sum256(debugPre[:]))
)
// invoiceRegistry is a central registry of all the outstanding invoices
// created by the daemon. The registry is a thin wrapper around a map in order
// to ensure that all updates/reads are thread safe.
type invoiceRegistry struct {
sync.RWMutex
cdb *channeldb.DB
clientMtx sync.Mutex
nextClientID uint32
notificationClients map[uint32]*invoiceSubscription
// debugInvoices is a mp which stores special "debug" invoices which
// handleUpstreamMsg processes wire messages related to commitment state
// updates from the upstream peer. The upstream peer is the peer whom we have a
// direct channel with, updating our respective commitment chains.
func (p *peer) handleUpstreamMsg(state *commitmentState, msg lnwire.Message) {
switch htlcPkt := msg.(type) {
// TODO(roasbeef): timeouts
// * fail if can't parse sphinx mix-header
case *lnwire.HTLCAddRequest:
// Before adding the new HTLC to the state machine, parse the
// onion object in order to obtain the routing information.
blobReader := bytes.NewReader(htlcPkt.OnionBlob)
onionPkt := &sphinx.OnionPacket{}
if err := onionPkt.Decode(blobReader); err != nil {
peerLog.Errorf("unable to decode onion pkt: %v", err)
p.Disconnect()
return
}
// Attempt to process the Sphinx packet. We include the payment
// hash of the HTLC as it's authenticated within the Sphinx
// packet itself as associated data in order to thwart attempts
// a replay attacks. In the case of a replay, an attacker is
// *forced* to use the same payment hash twice, thereby losing
// their money entirely.
rHash := htlcPkt.RedemptionHashes[0][:]
sphinxPacket, err := state.sphinx.ProcessOnionPacket(onionPkt, rHash)
if err != nil {
peerLog.Errorf("unable to process onion pkt: %v", err)
p.Disconnect()
return
}
// TODO(roasbeef): perform sanity checks on per-hop payload
// * time-lock is sane, fee, chain, etc
// We just received an add request from an upstream peer, so we
// add it to our state machine, then add the HTLC to our
// "settle" list in the event that we know the pre-image
index := state.channel.ReceiveHTLC(htlcPkt)
switch sphinxPacket.Action {
// We're the designated payment destination. Therefore we
// attempt to see if we have an invoice locally which'll allow
// us to settle this HTLC.
case sphinx.ExitNode:
rHash := htlcPkt.RedemptionHashes[0]
invoice, err := p.server.invoices.LookupInvoice(rHash)
if err != nil {
// TODO(roasbeef): send a canceHTLC message if we can't settle.
peerLog.Errorf("unable to query to locate: %v", err)
p.Disconnect()
return
}
// TODO(roasbeef): check values accept if >=
state.htlcsToSettle[index] = invoice
// There are additional hops left within this route, so we
// track the next hop according to the index of this HTLC
// within their log. When forwarding locked-in HLTC's to the
// switch, we'll attach the routing information so the switch
// can finalize the circuit.
case sphinx.MoreHops:
// TODO(roasbeef): send cancel + error if not in
// routing table
state.pendingCircuits[index] = sphinxPacket
default:
peerLog.Errorf("mal formed onion packet")
p.Disconnect()
}
case *lnwire.HTLCSettleRequest:
// TODO(roasbeef): this assumes no "multi-sig"
pre := htlcPkt.RedemptionProofs[0]
idx := uint32(htlcPkt.HTLCKey)
if err := state.channel.ReceiveHTLCSettle(pre, idx); err != nil {
// TODO(roasbeef): broadcast on-chain
peerLog.Errorf("settle for outgoing HTLC rejected: %v", err)
p.Disconnect()
return
}
// TODO(roasbeef): add pre-image to DB in order to swipe
// repeated r-values
case *lnwire.CommitSignature:
// We just received a new update to our local commitment chain,
// validate this new commitment, closing the link if invalid.
// TODO(roasbeef): use uint64 for indexes?
logIndex := uint32(htlcPkt.LogIndex)
sig := htlcPkt.CommitSig.Serialize()
if err := state.channel.ReceiveNewCommitment(sig, logIndex); err != nil {
peerLog.Errorf("unable to accept new commitment: %v", err)
p.Disconnect()
return
}
if state.numUnAcked > 0 {
state.numUnAcked -= 1
// TODO(roasbeef): only start if numUnacked == 0?
state.logCommitTimer = time.Tick(300 * time.Millisecond)
} else {
if _, err := p.updateCommitTx(state); err != nil {
peerLog.Errorf("unable to update "+
"commitment: %v", err)
p.Disconnect()
return
}
}
// Finally, since we just accepted a new state, send the remote
// peer a revocation for our prior state.
nextRevocation, err := state.channel.RevokeCurrentCommitment()
if err != nil {
peerLog.Errorf("unable to revoke current commitment: %v", err)
return
}
p.queueMsg(nextRevocation, nil)
case *lnwire.CommitRevocation:
// We've received a revocation from the remote chain, if valid,
// this moves the remote chain forward, and expands our
// revocation window.
htlcsToForward, err := state.channel.ReceiveRevocation(htlcPkt)
if err != nil {
peerLog.Errorf("unable to accept revocation: %v", err)
p.Disconnect()
return
}
// If any of the htlc's eligible for forwarding are pending
// settling or timeing out previous outgoing payments, then we
// can them from the pending set, and signal the requester (if
// existing) that the payment has been fully fulfilled.
var bandwidthUpdate btcutil.Amount
settledPayments := make(map[lnwallet.PaymentHash]struct{})
numSettled := 0
for _, htlc := range htlcsToForward {
if p, ok := state.clearedHTCLs[htlc.ParentIndex]; ok {
p.err <- nil
delete(state.clearedHTCLs, htlc.ParentIndex)
}
// TODO(roasbeef): rework log entries to a shared
// interface.
if htlc.EntryType != lnwallet.Add {
continue
}
// If we can't immediately settle this HTLC, then we
// can halt processing here.
invoice, ok := state.htlcsToSettle[htlc.Index]
if !ok {
continue
}
// Otherwise, we settle this HTLC within our local
// state update log, then send the update entry to the
// remote party.
preimage := invoice.Terms.PaymentPreimage
logIndex, err := state.channel.SettleHTLC(preimage)
if err != nil {
peerLog.Errorf("unable to settle htlc: %v", err)
p.Disconnect()
continue
}
settleMsg := &lnwire.HTLCSettleRequest{
ChannelPoint: state.chanPoint,
HTLCKey: lnwire.HTLCKey(logIndex),
RedemptionProofs: [][32]byte{preimage},
}
p.queueMsg(settleMsg, nil)
delete(state.htlcsToSettle, htlc.Index)
bandwidthUpdate += invoice.Terms.Value
settledPayments[htlc.RHash] = struct{}{}
numSettled++
}
go func() {
for _, htlc := range htlcsToForward {
// We don't need to forward any HTLC's that we
// just settled above.
// TODO(roasbeef): key by index insteaad?
if _, ok := settledPayments[htlc.RHash]; ok {
continue
}
onionPkt := state.pendingCircuits[htlc.Index]
delete(state.pendingCircuits, htlc.Index)
// Send this fully activated HTLC to the htlc
// switch to continue the chained clear/settle.
pkt, err := logEntryToHtlcPkt(*state.chanPoint,
htlc, onionPkt)
if err != nil {
peerLog.Errorf("unable to make htlc pkt: %v",
err)
continue
}
state.switchChan <- pkt
}
}()
if numSettled == 0 {
return
}
// Send an update to the htlc switch of our newly available
// payment bandwidth.
// TODO(roasbeef): ideally should wait for next state update.
if bandwidthUpdate != 0 {
p.server.htlcSwitch.UpdateLink(state.chanPoint,
bandwidthUpdate)
}
// With all the settle updates added to the local and remote
// HTLC logs, initiate a state transition by updating the
// remote commitment chain.
if sent, err := p.updateCommitTx(state); err != nil {
peerLog.Errorf("unable to update commitment: %v", err)
p.Disconnect()
return
} else if sent {
// TODO(roasbeef): wait to delete from htlcsToSettle?
state.numUnAcked += 1
}
// Notify the invoiceRegistry of the invoices we just settled
// with this latest commitment update.
// TODO(roasbeef): wait until next transition?
for invoice, _ := range settledPayments {
err := p.server.invoices.SettleInvoice(wire.ShaHash(invoice))
if err != nil {
peerLog.Errorf("unable to settle invoice: %v", err)
}
}
}
}
