lnd.xprv/channeldb/mp_payment.go

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package channeldb
import (
"bytes"
"errors"
"io"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/routing/route"
)
// HTLCAttemptInfo contains static information about a specific HTLC attempt
// for a payment. This information is used by the router to handle any errors
// coming back after an attempt is made, and to query the switch about the
// status of the attempt.
type HTLCAttemptInfo struct {
// AttemptID is the unique ID used for this attempt.
AttemptID uint64
// SessionKey is the ephemeral key used for this attempt.
SessionKey *btcec.PrivateKey
// Route is the route attempted to send the HTLC.
Route route.Route
// AttemptTime is the time at which this HTLC was attempted.
AttemptTime time.Time
}
// HTLCAttempt contains information about a specific HTLC attempt for a given
// payment. It contains the HTLCAttemptInfo used to send the HTLC, as well
// as a timestamp and any known outcome of the attempt.
type HTLCAttempt struct {
HTLCAttemptInfo
// Settle is the preimage of a successful payment. This serves as a
// proof of payment. It will only be non-nil for settled payments.
//
// NOTE: Can be nil if payment is not settled.
Settle *HTLCSettleInfo
// Fail is a failure reason code indicating the reason the payment
// failed. It is only non-nil for failed payments.
//
// NOTE: Can be nil if payment is not failed.
Failure *HTLCFailInfo
}
// HTLCSettleInfo encapsulates the information that augments an HTLCAttempt in
// the event that the HTLC is successful.
type HTLCSettleInfo struct {
// Preimage is the preimage of a successful HTLC. This serves as a proof
// of payment.
Preimage lntypes.Preimage
// SettleTime is the time at which this HTLC was settled.
SettleTime time.Time
}
// HTLCFailReason is the reason an htlc failed.
type HTLCFailReason byte
const (
// HTLCFailUnknown is recorded for htlcs that failed with an unknown
// reason.
HTLCFailUnknown HTLCFailReason = 0
// HTLCFailUnknown is recorded for htlcs that had a failure message that
// couldn't be decrypted.
HTLCFailUnreadable HTLCFailReason = 1
// HTLCFailInternal is recorded for htlcs that failed because of an
// internal error.
HTLCFailInternal HTLCFailReason = 2
// HTLCFailMessage is recorded for htlcs that failed with a network
// failure message.
HTLCFailMessage HTLCFailReason = 3
)
// HTLCFailInfo encapsulates the information that augments an HTLCAttempt in the
// event that the HTLC fails.
type HTLCFailInfo struct {
// FailTime is the time at which this HTLC was failed.
FailTime time.Time
// Message is the wire message that failed this HTLC. This field will be
// populated when the failure reason is HTLCFailMessage.
Message lnwire.FailureMessage
// Reason is the failure reason for this HTLC.
Reason HTLCFailReason
// The position in the path of the intermediate or final node that
// generated the failure message. Position zero is the sender node. This
// field will be populated when the failure reason is either
// HTLCFailMessage or HTLCFailUnknown.
FailureSourceIndex uint32
}
// MPPayment is a wrapper around a payment's PaymentCreationInfo and
// HTLCAttempts. All payments will have the PaymentCreationInfo set, any
// HTLCs made in attempts to be completed will populated in the HTLCs slice.
// Each populated HTLCAttempt represents an attempted HTLC, each of which may
// have the associated Settle or Fail struct populated if the HTLC is no longer
// in-flight.
type MPPayment struct {
// SequenceNum is a unique identifier used to sort the payments in
// order of creation.
SequenceNum uint64
// Info holds all static information about this payment, and is
// populated when the payment is initiated.
Info *PaymentCreationInfo
// HTLCs holds the information about individual HTLCs that we send in
// order to make the payment.
HTLCs []HTLCAttempt
// FailureReason is the failure reason code indicating the reason the
// payment failed.
//
// NOTE: Will only be set once the daemon has given up on the payment
// altogether.
FailureReason *FailureReason
// Status is the current PaymentStatus of this payment.
Status PaymentStatus
}
// TerminalInfo returns any HTLC settle info recorded. If no settle info is
// recorded, any payment level failure will be returned. If neither a settle
// nor a failure is recorded, both return values will be nil.
func (m *MPPayment) TerminalInfo() (*HTLCSettleInfo, *FailureReason) {
for _, h := range m.HTLCs {
if h.Settle != nil {
return h.Settle, nil
}
}
return nil, m.FailureReason
}
// SentAmt returns the sum of sent amount and fees for HTLCs that are either
// settled or still in flight.
func (m *MPPayment) SentAmt() (lnwire.MilliSatoshi, lnwire.MilliSatoshi) {
var sent, fees lnwire.MilliSatoshi
for _, h := range m.HTLCs {
if h.Failure != nil {
continue
}
// The attempt was not failed, meaning the amount was
// potentially sent to the receiver.
sent += h.Route.ReceiverAmt()
fees += h.Route.TotalFees()
}
return sent, fees
}
// InFlightHTLCs returns the HTLCs that are still in-flight, meaning they have
// not been settled or failed.
func (m *MPPayment) InFlightHTLCs() []HTLCAttempt {
var inflights []HTLCAttempt
for _, h := range m.HTLCs {
if h.Settle != nil || h.Failure != nil {
continue
}
inflights = append(inflights, h)
}
return inflights
}
// GetAttempt returns the specified htlc attempt on the payment.
func (m *MPPayment) GetAttempt(id uint64) (*HTLCAttempt, error) {
for _, htlc := range m.HTLCs {
htlc := htlc
if htlc.AttemptID == id {
return &htlc, nil
}
}
return nil, errors.New("htlc attempt not found on payment")
}
// serializeHTLCSettleInfo serializes the details of a settled htlc.
func serializeHTLCSettleInfo(w io.Writer, s *HTLCSettleInfo) error {
if _, err := w.Write(s.Preimage[:]); err != nil {
return err
}
if err := serializeTime(w, s.SettleTime); err != nil {
return err
}
return nil
}
// deserializeHTLCSettleInfo deserializes the details of a settled htlc.
func deserializeHTLCSettleInfo(r io.Reader) (*HTLCSettleInfo, error) {
s := &HTLCSettleInfo{}
if _, err := io.ReadFull(r, s.Preimage[:]); err != nil {
return nil, err
}
var err error
s.SettleTime, err = deserializeTime(r)
if err != nil {
return nil, err
}
return s, nil
}
// serializeHTLCFailInfo serializes the details of a failed htlc including the
// wire failure.
func serializeHTLCFailInfo(w io.Writer, f *HTLCFailInfo) error {
if err := serializeTime(w, f.FailTime); err != nil {
return err
}
// Write failure. If there is no failure message, write an empty
// byte slice.
var messageBytes bytes.Buffer
if f.Message != nil {
err := lnwire.EncodeFailureMessage(&messageBytes, f.Message, 0)
if err != nil {
return err
}
}
if err := wire.WriteVarBytes(w, 0, messageBytes.Bytes()); err != nil {
return err
}
return WriteElements(w, byte(f.Reason), f.FailureSourceIndex)
}
// deserializeHTLCFailInfo deserializes the details of a failed htlc including
// the wire failure.
func deserializeHTLCFailInfo(r io.Reader) (*HTLCFailInfo, error) {
f := &HTLCFailInfo{}
var err error
f.FailTime, err = deserializeTime(r)
if err != nil {
return nil, err
}
// Read failure.
failureBytes, err := wire.ReadVarBytes(
r, 0, lnwire.FailureMessageLength, "failure",
)
if err != nil {
return nil, err
}
if len(failureBytes) > 0 {
f.Message, err = lnwire.DecodeFailureMessage(
bytes.NewReader(failureBytes), 0,
)
if err != nil {
return nil, err
}
}
var reason byte
err = ReadElements(r, &reason, &f.FailureSourceIndex)
if err != nil {
return nil, err
}
f.Reason = HTLCFailReason(reason)
return f, nil
}
// deserializeTime deserializes time as unix nanoseconds.
func deserializeTime(r io.Reader) (time.Time, error) {
var scratch [8]byte
if _, err := io.ReadFull(r, scratch[:]); err != nil {
return time.Time{}, err
}
// Convert to time.Time. Interpret unix nano time zero as a zero
// time.Time value.
unixNano := byteOrder.Uint64(scratch[:])
if unixNano == 0 {
return time.Time{}, nil
}
return time.Unix(0, int64(unixNano)), nil
}
// serializeTime serializes time as unix nanoseconds.
func serializeTime(w io.Writer, t time.Time) error {
var scratch [8]byte
// Convert to unix nano seconds, but only if time is non-zero. Calling
// UnixNano() on a zero time yields an undefined result.
var unixNano int64
if !t.IsZero() {
unixNano = t.UnixNano()
}
byteOrder.PutUint64(scratch[:], uint64(unixNano))
_, err := w.Write(scratch[:])
return err
}