e61fcda6a9
To prepare for having more than one payment attempt in flight at the same time, we decouple fetching the next route from crafting the payment attempt.
512 lines
14 KiB
Go
512 lines
14 KiB
Go
package routing
|
|
|
|
import (
|
|
"fmt"
|
|
"time"
|
|
|
|
"github.com/davecgh/go-spew/spew"
|
|
sphinx "github.com/lightningnetwork/lightning-onion"
|
|
"github.com/lightningnetwork/lnd/channeldb"
|
|
"github.com/lightningnetwork/lnd/htlcswitch"
|
|
"github.com/lightningnetwork/lnd/lntypes"
|
|
"github.com/lightningnetwork/lnd/lnwire"
|
|
"github.com/lightningnetwork/lnd/routing/route"
|
|
)
|
|
|
|
// errNoRoute is returned when all routes from the payment session have been
|
|
// attempted.
|
|
type errNoRoute struct {
|
|
// lastError is the error encountered during the last payment attempt,
|
|
// if at least one attempt has been made.
|
|
lastError error
|
|
}
|
|
|
|
// Error returns a string representation of the error.
|
|
func (e errNoRoute) Error() string {
|
|
return fmt.Sprintf("unable to route payment to destination: %v",
|
|
e.lastError)
|
|
}
|
|
|
|
// paymentLifecycle holds all information about the current state of a payment
|
|
// needed to resume if from any point.
|
|
type paymentLifecycle struct {
|
|
router *ChannelRouter
|
|
totalAmount lnwire.MilliSatoshi
|
|
feeLimit lnwire.MilliSatoshi
|
|
paymentHash lntypes.Hash
|
|
paySession PaymentSession
|
|
timeoutChan <-chan time.Time
|
|
currentHeight int32
|
|
attempt *channeldb.HTLCAttemptInfo
|
|
circuit *sphinx.Circuit
|
|
lastError error
|
|
}
|
|
|
|
// resumePayment resumes the paymentLifecycle from the current state.
|
|
func (p *paymentLifecycle) resumePayment() ([32]byte, *route.Route, error) {
|
|
// We'll continue until either our payment succeeds, or we encounter a
|
|
// critical error during path finding.
|
|
for {
|
|
|
|
// If this payment had no existing payment attempt, we create
|
|
// and send one now.
|
|
if p.attempt == nil {
|
|
// Before we attempt this next payment, we'll check to see if either
|
|
// we've gone past the payment attempt timeout, or the router is
|
|
// exiting. In either case, we'll stop this payment attempt short. If a
|
|
// timeout is not applicable, timeoutChan will be nil.
|
|
select {
|
|
case <-p.timeoutChan:
|
|
// Mark the payment as failed because of the
|
|
// timeout.
|
|
err := p.router.cfg.Control.Fail(
|
|
p.paymentHash, channeldb.FailureReasonTimeout,
|
|
)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
errStr := fmt.Sprintf("payment attempt not completed " +
|
|
"before timeout")
|
|
|
|
return [32]byte{}, nil, newErr(ErrPaymentAttemptTimeout, errStr)
|
|
|
|
// The payment will be resumed from the current state
|
|
// after restart.
|
|
case <-p.router.quit:
|
|
return [32]byte{}, nil, ErrRouterShuttingDown
|
|
|
|
// Fall through if we haven't hit our time limit or are
|
|
// exiting.
|
|
default:
|
|
}
|
|
|
|
// Create a new payment attempt from the given payment session.
|
|
rt, err := p.paySession.RequestRoute(
|
|
p.totalAmount, p.feeLimit, 0, uint32(p.currentHeight),
|
|
)
|
|
if err != nil {
|
|
log.Warnf("Failed to find route for payment %x: %v",
|
|
p.paymentHash, err)
|
|
|
|
// Convert error to payment-level failure.
|
|
failure := errorToPaymentFailure(err)
|
|
|
|
// If we're unable to successfully make a payment using
|
|
// any of the routes we've found, then mark the payment
|
|
// as permanently failed.
|
|
saveErr := p.router.cfg.Control.Fail(
|
|
p.paymentHash, failure,
|
|
)
|
|
if saveErr != nil {
|
|
return [32]byte{}, nil, saveErr
|
|
}
|
|
|
|
// If there was an error already recorded for this
|
|
// payment, we'll return that.
|
|
if p.lastError != nil {
|
|
return [32]byte{}, nil, errNoRoute{lastError: p.lastError}
|
|
}
|
|
|
|
// Terminal state, return.
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Using the route received from the payment session,
|
|
// create a new shard to send.
|
|
firstHop, htlcAdd, err := p.createNewPaymentAttempt(
|
|
rt,
|
|
)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Now that the attempt is created and checkpointed to
|
|
// the DB, we send it.
|
|
sendErr := p.sendPaymentAttempt(firstHop, htlcAdd)
|
|
if sendErr != nil {
|
|
// TODO(joostjager): Distinguish unexpected
|
|
// internal errors from real send errors.
|
|
err = p.failAttempt(sendErr)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// We must inspect the error to know whether it
|
|
// was critical or not, to decide whether we
|
|
// should continue trying.
|
|
err := p.handleSendError(sendErr)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Error was handled successfully, reset the
|
|
// attempt to indicate we want to make a new
|
|
// attempt.
|
|
p.attempt = nil
|
|
continue
|
|
}
|
|
} else {
|
|
// If this was a resumed attempt, we must regenerate the
|
|
// circuit. We don't need to check for errors resulting
|
|
// from an invalid route, because the sphinx packet has
|
|
// been successfully generated before.
|
|
_, c, err := generateSphinxPacket(
|
|
&p.attempt.Route, p.paymentHash[:],
|
|
p.attempt.SessionKey,
|
|
)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
p.circuit = c
|
|
}
|
|
|
|
// Using the created circuit, initialize the error decrypter so we can
|
|
// parse+decode any failures incurred by this payment within the
|
|
// switch.
|
|
errorDecryptor := &htlcswitch.SphinxErrorDecrypter{
|
|
OnionErrorDecrypter: sphinx.NewOnionErrorDecrypter(p.circuit),
|
|
}
|
|
|
|
// Now ask the switch to return the result of the payment when
|
|
// available.
|
|
resultChan, err := p.router.cfg.Payer.GetPaymentResult(
|
|
p.attempt.AttemptID, p.paymentHash, errorDecryptor,
|
|
)
|
|
switch {
|
|
|
|
// If this attempt ID is unknown to the Switch, it means it was
|
|
// never checkpointed and forwarded by the switch before a
|
|
// restart. In this case we can safely send a new payment
|
|
// attempt, and wait for its result to be available.
|
|
case err == htlcswitch.ErrPaymentIDNotFound:
|
|
log.Debugf("Payment ID %v for hash %x not found in "+
|
|
"the Switch, retrying.", p.attempt.AttemptID,
|
|
p.paymentHash)
|
|
|
|
err = p.failAttempt(err)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Reset the attempt to indicate we want to make a new
|
|
// attempt.
|
|
p.attempt = nil
|
|
continue
|
|
|
|
// A critical, unexpected error was encountered.
|
|
case err != nil:
|
|
log.Errorf("Failed getting result for attemptID %d "+
|
|
"from switch: %v", p.attempt.AttemptID, err)
|
|
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// The switch knows about this payment, we'll wait for a result
|
|
// to be available.
|
|
var (
|
|
result *htlcswitch.PaymentResult
|
|
ok bool
|
|
)
|
|
|
|
select {
|
|
case result, ok = <-resultChan:
|
|
if !ok {
|
|
return [32]byte{}, nil, htlcswitch.ErrSwitchExiting
|
|
}
|
|
|
|
case <-p.router.quit:
|
|
return [32]byte{}, nil, ErrRouterShuttingDown
|
|
}
|
|
|
|
// In case of a payment failure, we use the error to decide
|
|
// whether we should retry.
|
|
if result.Error != nil {
|
|
log.Errorf("Attempt to send payment %x failed: %v",
|
|
p.paymentHash, result.Error)
|
|
|
|
err = p.failAttempt(result.Error)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// We must inspect the error to know whether it was
|
|
// critical or not, to decide whether we should
|
|
// continue trying.
|
|
if err := p.handleSendError(result.Error); err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Error was handled successfully, reset the attempt to
|
|
// indicate we want to make a new attempt.
|
|
p.attempt = nil
|
|
continue
|
|
}
|
|
|
|
// We successfully got a payment result back from the switch.
|
|
log.Debugf("Payment %x succeeded with pid=%v",
|
|
p.paymentHash, p.attempt.AttemptID)
|
|
|
|
// Report success to mission control.
|
|
err = p.router.cfg.MissionControl.ReportPaymentSuccess(
|
|
p.attempt.AttemptID, &p.attempt.Route,
|
|
)
|
|
if err != nil {
|
|
log.Errorf("Error reporting payment success to mc: %v",
|
|
err)
|
|
}
|
|
|
|
// In case of success we atomically store the db payment and
|
|
// move the payment to the success state.
|
|
err = p.router.cfg.Control.SettleAttempt(
|
|
p.paymentHash, p.attempt.AttemptID,
|
|
&channeldb.HTLCSettleInfo{
|
|
Preimage: result.Preimage,
|
|
SettleTime: p.router.cfg.Clock.Now(),
|
|
},
|
|
)
|
|
if err != nil {
|
|
log.Errorf("Unable to succeed payment "+
|
|
"attempt: %v", err)
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Terminal state, return the preimage and the route
|
|
// taken.
|
|
return result.Preimage, &p.attempt.Route, nil
|
|
}
|
|
|
|
}
|
|
|
|
// errorToPaymentFailure takes a path finding error and converts it into a
|
|
// payment-level failure.
|
|
func errorToPaymentFailure(err error) channeldb.FailureReason {
|
|
switch err {
|
|
case
|
|
errNoTlvPayload,
|
|
errNoPaymentAddr,
|
|
errNoPathFound,
|
|
errPrebuiltRouteTried:
|
|
|
|
return channeldb.FailureReasonNoRoute
|
|
|
|
case errInsufficientBalance:
|
|
return channeldb.FailureReasonInsufficientBalance
|
|
}
|
|
|
|
return channeldb.FailureReasonError
|
|
}
|
|
|
|
// createNewPaymentAttempt creates and stores a new payment attempt to the
|
|
// database.
|
|
func (p *paymentLifecycle) createNewPaymentAttempt(rt *route.Route) (lnwire.ShortChannelID,
|
|
*lnwire.UpdateAddHTLC, error) {
|
|
|
|
// Generate a new key to be used for this attempt.
|
|
sessionKey, err := generateNewSessionKey()
|
|
if err != nil {
|
|
return lnwire.ShortChannelID{}, nil, err
|
|
}
|
|
|
|
// Generate the raw encoded sphinx packet to be included along
|
|
// with the htlcAdd message that we send directly to the
|
|
// switch.
|
|
onionBlob, c, err := generateSphinxPacket(
|
|
rt, p.paymentHash[:], sessionKey,
|
|
)
|
|
|
|
// With SendToRoute, it can happen that the route exceeds protocol
|
|
// constraints. Mark the payment as failed with an internal error.
|
|
if err == route.ErrMaxRouteHopsExceeded ||
|
|
err == sphinx.ErrMaxRoutingInfoSizeExceeded {
|
|
|
|
log.Debugf("Invalid route provided for payment %x: %v",
|
|
p.paymentHash, err)
|
|
|
|
controlErr := p.router.cfg.Control.Fail(
|
|
p.paymentHash, channeldb.FailureReasonError,
|
|
)
|
|
if controlErr != nil {
|
|
return lnwire.ShortChannelID{}, nil, controlErr
|
|
}
|
|
}
|
|
|
|
// In any case, don't continue if there is an error.
|
|
if err != nil {
|
|
return lnwire.ShortChannelID{}, nil, err
|
|
}
|
|
|
|
// Update our cached circuit with the newly generated
|
|
// one.
|
|
p.circuit = c
|
|
|
|
// Craft an HTLC packet to send to the layer 2 switch. The
|
|
// metadata within this packet will be used to route the
|
|
// payment through the network, starting with the first-hop.
|
|
htlcAdd := &lnwire.UpdateAddHTLC{
|
|
Amount: rt.TotalAmount,
|
|
Expiry: rt.TotalTimeLock,
|
|
PaymentHash: p.paymentHash,
|
|
}
|
|
copy(htlcAdd.OnionBlob[:], onionBlob)
|
|
|
|
// Attempt to send this payment through the network to complete
|
|
// the payment. If this attempt fails, then we'll continue on
|
|
// to the next available route.
|
|
firstHop := lnwire.NewShortChanIDFromInt(
|
|
rt.Hops[0].ChannelID,
|
|
)
|
|
|
|
// We generate a new, unique payment ID that we will use for
|
|
// this HTLC.
|
|
attemptID, err := p.router.cfg.NextPaymentID()
|
|
if err != nil {
|
|
return lnwire.ShortChannelID{}, nil, err
|
|
}
|
|
|
|
// We now have all the information needed to populate
|
|
// the current attempt information.
|
|
p.attempt = &channeldb.HTLCAttemptInfo{
|
|
AttemptID: attemptID,
|
|
AttemptTime: p.router.cfg.Clock.Now(),
|
|
SessionKey: sessionKey,
|
|
Route: *rt,
|
|
}
|
|
|
|
// Before sending this HTLC to the switch, we checkpoint the
|
|
// fresh attemptID and route to the DB. This lets us know on
|
|
// startup the ID of the payment that we attempted to send,
|
|
// such that we can query the Switch for its whereabouts. The
|
|
// route is needed to handle the result when it eventually
|
|
// comes back.
|
|
err = p.router.cfg.Control.RegisterAttempt(p.paymentHash, p.attempt)
|
|
if err != nil {
|
|
return lnwire.ShortChannelID{}, nil, err
|
|
}
|
|
|
|
return firstHop, htlcAdd, nil
|
|
}
|
|
|
|
// sendPaymentAttempt attempts to send the current attempt to the switch.
|
|
func (p *paymentLifecycle) sendPaymentAttempt(firstHop lnwire.ShortChannelID,
|
|
htlcAdd *lnwire.UpdateAddHTLC) error {
|
|
|
|
log.Tracef("Attempting to send payment %x (pid=%v), "+
|
|
"using route: %v", p.paymentHash, p.attempt.AttemptID,
|
|
newLogClosure(func() string {
|
|
return spew.Sdump(p.attempt.Route)
|
|
}),
|
|
)
|
|
|
|
// Send it to the Switch. When this method returns we assume
|
|
// the Switch successfully has persisted the payment attempt,
|
|
// such that we can resume waiting for the result after a
|
|
// restart.
|
|
err := p.router.cfg.Payer.SendHTLC(
|
|
firstHop, p.attempt.AttemptID, htlcAdd,
|
|
)
|
|
if err != nil {
|
|
log.Errorf("Failed sending attempt %d for payment "+
|
|
"%x to switch: %v", p.attempt.AttemptID,
|
|
p.paymentHash, err)
|
|
return err
|
|
}
|
|
|
|
log.Debugf("Payment %x (pid=%v) successfully sent to switch, route: %v",
|
|
p.paymentHash, p.attempt.AttemptID, &p.attempt.Route)
|
|
|
|
return nil
|
|
}
|
|
|
|
// handleSendError inspects the given error from the Switch and determines
|
|
// whether we should make another payment attempt.
|
|
func (p *paymentLifecycle) handleSendError(sendErr error) error {
|
|
|
|
reason := p.router.processSendError(
|
|
p.attempt.AttemptID, &p.attempt.Route, sendErr,
|
|
)
|
|
if reason == nil {
|
|
// Save the forwarding error so it can be returned if
|
|
// this turns out to be the last attempt.
|
|
p.lastError = sendErr
|
|
|
|
return nil
|
|
}
|
|
|
|
log.Debugf("Payment %x failed: final_outcome=%v, raw_err=%v",
|
|
p.paymentHash, *reason, sendErr)
|
|
|
|
// Mark the payment failed with no route.
|
|
//
|
|
// TODO(halseth): make payment codes for the actual reason we don't
|
|
// continue path finding.
|
|
err := p.router.cfg.Control.Fail(
|
|
p.paymentHash, *reason,
|
|
)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// Terminal state, return the error we encountered.
|
|
return sendErr
|
|
}
|
|
|
|
// failAttempt calls control tower to fail the current payment attempt.
|
|
func (p *paymentLifecycle) failAttempt(sendError error) error {
|
|
failInfo := marshallError(
|
|
sendError,
|
|
p.router.cfg.Clock.Now(),
|
|
)
|
|
|
|
return p.router.cfg.Control.FailAttempt(
|
|
p.paymentHash, p.attempt.AttemptID,
|
|
failInfo,
|
|
)
|
|
}
|
|
|
|
// marshallError marshall an error as received from the switch to a structure
|
|
// that is suitable for database storage.
|
|
func marshallError(sendError error, time time.Time) *channeldb.HTLCFailInfo {
|
|
response := &channeldb.HTLCFailInfo{
|
|
FailTime: time,
|
|
}
|
|
|
|
switch sendError {
|
|
|
|
case htlcswitch.ErrPaymentIDNotFound:
|
|
response.Reason = channeldb.HTLCFailInternal
|
|
return response
|
|
|
|
case htlcswitch.ErrUnreadableFailureMessage:
|
|
response.Reason = channeldb.HTLCFailUnreadable
|
|
return response
|
|
}
|
|
|
|
rtErr, ok := sendError.(htlcswitch.ClearTextError)
|
|
if !ok {
|
|
response.Reason = channeldb.HTLCFailInternal
|
|
return response
|
|
}
|
|
|
|
message := rtErr.WireMessage()
|
|
if message != nil {
|
|
response.Reason = channeldb.HTLCFailMessage
|
|
response.Message = message
|
|
} else {
|
|
response.Reason = channeldb.HTLCFailUnknown
|
|
}
|
|
|
|
// If the ClearTextError received is a ForwardingError, the error
|
|
// originated from a node along the route, not locally on our outgoing
|
|
// link. We set failureSourceIdx to the index of the node where the
|
|
// failure occurred. If the error is not a ForwardingError, the failure
|
|
// occurred at our node, so we leave the index as 0 to indicate that
|
|
// we failed locally.
|
|
fErr, ok := rtErr.(*htlcswitch.ForwardingError)
|
|
if ok {
|
|
response.FailureSourceIndex = uint32(fErr.FailureSourceIdx)
|
|
}
|
|
|
|
return response
|
|
}
|