lnd.xprv/channeldb/payments.go
2019-12-04 09:45:07 +01:00

776 lines
20 KiB
Go

package channeldb
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"io"
"sort"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/wire"
"github.com/coreos/bbolt"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/record"
"github.com/lightningnetwork/lnd/routing/route"
"github.com/lightningnetwork/lnd/tlv"
)
var (
// paymentsRootBucket is the name of the top-level bucket within the
// database that stores all data related to payments. Within this
// bucket, each payment hash its own sub-bucket keyed by its payment
// hash.
//
// Bucket hierarchy:
//
// root-bucket
// |
// |-- <paymenthash>
// | |--sequence-key: <sequence number>
// | |--creation-info-key: <creation info>
// | |--attempt-info-key: <attempt info>
// | |--settle-info-key: <settle info>
// | |--fail-info-key: <fail info>
// | |
// | |--duplicate-bucket (only for old, completed payments)
// | |
// | |-- <seq-num>
// | | |--sequence-key: <sequence number>
// | | |--creation-info-key: <creation info>
// | | |--attempt-info-key: <attempt info>
// | | |--settle-info-key: <settle info>
// | | |--fail-info-key: <fail info>
// | |
// | |-- <seq-num>
// | | |
// | ... ...
// |
// |-- <paymenthash>
// | |
// | ...
// ...
//
paymentsRootBucket = []byte("payments-root-bucket")
// paymentDublicateBucket is the name of a optional sub-bucket within
// the payment hash bucket, that is used to hold duplicate payments to
// a payment hash. This is needed to support information from earlier
// versions of lnd, where it was possible to pay to a payment hash more
// than once.
paymentDuplicateBucket = []byte("payment-duplicate-bucket")
// paymentSequenceKey is a key used in the payment's sub-bucket to
// store the sequence number of the payment.
paymentSequenceKey = []byte("payment-sequence-key")
// paymentCreationInfoKey is a key used in the payment's sub-bucket to
// store the creation info of the payment.
paymentCreationInfoKey = []byte("payment-creation-info")
// paymentAttemptInfoKey is a key used in the payment's sub-bucket to
// store the info about the latest attempt that was done for the
// payment in question.
paymentAttemptInfoKey = []byte("payment-attempt-info")
// paymentSettleInfoKey is a key used in the payment's sub-bucket to
// store the settle info of the payment.
paymentSettleInfoKey = []byte("payment-settle-info")
// paymentFailInfoKey is a key used in the payment's sub-bucket to
// store information about the reason a payment failed.
paymentFailInfoKey = []byte("payment-fail-info")
)
// FailureReason encodes the reason a payment ultimately failed.
type FailureReason byte
const (
// FailureReasonTimeout indicates that the payment did timeout before a
// successful payment attempt was made.
FailureReasonTimeout FailureReason = 0
// FailureReasonNoRoute indicates no successful route to the
// destination was found during path finding.
FailureReasonNoRoute FailureReason = 1
// FailureReasonError indicates that an unexpected error happened during
// payment.
FailureReasonError FailureReason = 2
// FailureReasonPaymentDetails indicates that either the hash is unknown
// or the final cltv delta or amount is incorrect.
FailureReasonPaymentDetails FailureReason = 3
// FailureReasonInsufficientBalance indicates that we didn't have enough
// balance to complete the payment.
FailureReasonInsufficientBalance FailureReason = 4
// TODO(halseth): cancel state.
// TODO(joostjager): Add failure reasons for:
// LocalLiquidityInsufficient, RemoteCapacityInsufficient.
)
// String returns a human readable FailureReason
func (r FailureReason) String() string {
switch r {
case FailureReasonTimeout:
return "timeout"
case FailureReasonNoRoute:
return "no_route"
case FailureReasonError:
return "error"
case FailureReasonPaymentDetails:
return "incorrect_payment_details"
case FailureReasonInsufficientBalance:
return "insufficient_balance"
}
return "unknown"
}
// PaymentStatus represent current status of payment
type PaymentStatus byte
const (
// StatusUnknown is the status where a payment has never been initiated
// and hence is unknown.
StatusUnknown PaymentStatus = 0
// StatusInFlight is the status where a payment has been initiated, but
// a response has not been received.
StatusInFlight PaymentStatus = 1
// StatusSucceeded is the status where a payment has been initiated and
// the payment was completed successfully.
StatusSucceeded PaymentStatus = 2
// StatusFailed is the status where a payment has been initiated and a
// failure result has come back.
StatusFailed PaymentStatus = 3
)
// Bytes returns status as slice of bytes.
func (ps PaymentStatus) Bytes() []byte {
return []byte{byte(ps)}
}
// FromBytes sets status from slice of bytes.
func (ps *PaymentStatus) FromBytes(status []byte) error {
if len(status) != 1 {
return errors.New("payment status is empty")
}
switch PaymentStatus(status[0]) {
case StatusUnknown, StatusInFlight, StatusSucceeded, StatusFailed:
*ps = PaymentStatus(status[0])
default:
return errors.New("unknown payment status")
}
return nil
}
// String returns readable representation of payment status.
func (ps PaymentStatus) String() string {
switch ps {
case StatusUnknown:
return "Unknown"
case StatusInFlight:
return "In Flight"
case StatusSucceeded:
return "Succeeded"
case StatusFailed:
return "Failed"
default:
return "Unknown"
}
}
// PaymentCreationInfo is the information necessary to have ready when
// initiating a payment, moving it into state InFlight.
type PaymentCreationInfo struct {
// PaymentHash is the hash this payment is paying to.
PaymentHash lntypes.Hash
// Value is the amount we are paying.
Value lnwire.MilliSatoshi
// CreatingDate is the time when this payment was initiated.
CreationDate time.Time
// PaymentRequest is the full payment request, if any.
PaymentRequest []byte
}
// PaymentAttemptInfo contains information about a specific payment attempt for
// a given 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 a payment. For settled payment this will be the information for
// the succeeding payment attempt.
type PaymentAttemptInfo struct {
// PaymentID is the unique ID used for this attempt.
PaymentID uint64
// SessionKey is the ephemeral key used for this payment attempt.
SessionKey *btcec.PrivateKey
// Route is the route attempted to send the HTLC.
Route route.Route
}
// Payment is a wrapper around a payment's PaymentCreationInfo,
// PaymentAttemptInfo, and preimage. All payments will have the
// PaymentCreationInfo set, the PaymentAttemptInfo will be set only if at least
// one payment attempt has been made, while only completed payments will have a
// non-zero payment preimage.
type Payment struct {
// sequenceNum is a unique identifier used to sort the payments in
// order of creation.
sequenceNum uint64
// Status is the current PaymentStatus of this payment.
Status PaymentStatus
// Info holds all static information about this payment, and is
// populated when the payment is initiated.
Info *PaymentCreationInfo
// Attempt is the information about the last payment attempt made.
//
// NOTE: Can be nil if no attempt is yet made.
Attempt *PaymentAttemptInfo
// Preimage 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.
Preimage *lntypes.Preimage
// Failure 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 *FailureReason
}
// ToMPPayment converts a legacy payment into an MPPayment.
func (p *Payment) ToMPPayment() *MPPayment {
var (
htlcs []HTLCAttempt
reason *FailureReason
settle *HTLCSettleInfo
failure *HTLCFailInfo
)
// Promote the payment failure to a proper fail struct, if it exists.
if p.Failure != nil {
// NOTE: FailTime is not set for legacy payments.
failure = &HTLCFailInfo{}
reason = p.Failure
}
// Promote the payment preimage to proper settle struct, if it exists.
if p.Preimage != nil {
// NOTE: SettleTime is not set for legacy payments.
settle = &HTLCSettleInfo{
Preimage: *p.Preimage,
}
}
// Either a settle or a failure may be set, but not both.
if settle != nil && failure != nil {
panic("htlc attempt has both settle and failure info")
}
// Populate a single HTLC on the MPPayment if an attempt exists on the
// legacy payment. If none exists we will leave the attempt info blank
// since we cannot recover it.
if p.Attempt != nil {
// NOTE: AttemptTime is not set for legacy payments.
htlcs = []HTLCAttempt{
{
PaymentID: p.Attempt.PaymentID,
SessionKey: p.Attempt.SessionKey,
Route: p.Attempt.Route,
Settle: settle,
Failure: failure,
},
}
}
return &MPPayment{
sequenceNum: p.sequenceNum,
Info: &MPPaymentCreationInfo{
PaymentHash: p.Info.PaymentHash,
Value: p.Info.Value,
CreationTime: p.Info.CreationDate,
PaymentRequest: p.Info.PaymentRequest,
},
HTLCs: htlcs,
FailureReason: reason,
Status: p.Status,
}
}
// FetchPayments returns all sent payments found in the DB.
//
// nolint: dupl
func (db *DB) FetchPayments() ([]*MPPayment, error) {
var payments []*MPPayment
err := db.View(func(tx *bbolt.Tx) error {
paymentsBucket := tx.Bucket(paymentsRootBucket)
if paymentsBucket == nil {
return nil
}
return paymentsBucket.ForEach(func(k, v []byte) error {
bucket := paymentsBucket.Bucket(k)
if bucket == nil {
// We only expect sub-buckets to be found in
// this top-level bucket.
return fmt.Errorf("non bucket element in " +
"payments bucket")
}
p, err := fetchPayment(bucket)
if err != nil {
return err
}
payments = append(payments, p)
// For older versions of lnd, duplicate payments to a
// payment has was possible. These will be found in a
// sub-bucket indexed by their sequence number if
// available.
dup := bucket.Bucket(paymentDuplicateBucket)
if dup == nil {
return nil
}
return dup.ForEach(func(k, v []byte) error {
subBucket := dup.Bucket(k)
if subBucket == nil {
// We one bucket for each duplicate to
// be found.
return fmt.Errorf("non bucket element" +
"in duplicate bucket")
}
p, err := fetchPayment(subBucket)
if err != nil {
return err
}
payments = append(payments, p)
return nil
})
})
})
if err != nil {
return nil, err
}
// Before returning, sort the payments by their sequence number.
sort.Slice(payments, func(i, j int) bool {
return payments[i].sequenceNum < payments[j].sequenceNum
})
return payments, nil
}
func fetchPayment(bucket *bbolt.Bucket) (*MPPayment, error) {
var (
err error
p = &Payment{}
)
seqBytes := bucket.Get(paymentSequenceKey)
if seqBytes == nil {
return nil, fmt.Errorf("sequence number not found")
}
p.sequenceNum = binary.BigEndian.Uint64(seqBytes)
// Get the payment status.
p.Status = fetchPaymentStatus(bucket)
// Get the PaymentCreationInfo.
b := bucket.Get(paymentCreationInfoKey)
if b == nil {
return nil, fmt.Errorf("creation info not found")
}
r := bytes.NewReader(b)
p.Info, err = deserializePaymentCreationInfo(r)
if err != nil {
return nil, err
}
// Get the PaymentAttemptInfo. This can be unset.
b = bucket.Get(paymentAttemptInfoKey)
if b != nil {
r = bytes.NewReader(b)
p.Attempt, err = deserializePaymentAttemptInfo(r)
if err != nil {
return nil, err
}
}
// Get the payment preimage. This is only found for
// completed payments.
b = bucket.Get(paymentSettleInfoKey)
if b != nil {
var preimg lntypes.Preimage
copy(preimg[:], b[:])
p.Preimage = &preimg
}
// Get failure reason if available.
b = bucket.Get(paymentFailInfoKey)
if b != nil {
reason := FailureReason(b[0])
p.Failure = &reason
}
return p.ToMPPayment(), nil
}
// DeletePayments deletes all completed and failed payments from the DB.
func (db *DB) DeletePayments() error {
return db.Update(func(tx *bbolt.Tx) error {
payments := tx.Bucket(paymentsRootBucket)
if payments == nil {
return nil
}
var deleteBuckets [][]byte
err := payments.ForEach(func(k, _ []byte) error {
bucket := payments.Bucket(k)
if bucket == nil {
// We only expect sub-buckets to be found in
// this top-level bucket.
return fmt.Errorf("non bucket element in " +
"payments bucket")
}
// If the status is InFlight, we cannot safely delete
// the payment information, so we return early.
paymentStatus := fetchPaymentStatus(bucket)
if paymentStatus == StatusInFlight {
return nil
}
deleteBuckets = append(deleteBuckets, k)
return nil
})
if err != nil {
return err
}
for _, k := range deleteBuckets {
if err := payments.DeleteBucket(k); err != nil {
return err
}
}
return nil
})
}
func serializePaymentCreationInfo(w io.Writer, c *PaymentCreationInfo) error {
var scratch [8]byte
if _, err := w.Write(c.PaymentHash[:]); err != nil {
return err
}
byteOrder.PutUint64(scratch[:], uint64(c.Value))
if _, err := w.Write(scratch[:]); err != nil {
return err
}
byteOrder.PutUint64(scratch[:], uint64(c.CreationDate.Unix()))
if _, err := w.Write(scratch[:]); err != nil {
return err
}
byteOrder.PutUint32(scratch[:4], uint32(len(c.PaymentRequest)))
if _, err := w.Write(scratch[:4]); err != nil {
return err
}
if _, err := w.Write(c.PaymentRequest[:]); err != nil {
return err
}
return nil
}
func deserializePaymentCreationInfo(r io.Reader) (*PaymentCreationInfo, error) {
var scratch [8]byte
c := &PaymentCreationInfo{}
if _, err := io.ReadFull(r, c.PaymentHash[:]); err != nil {
return nil, err
}
if _, err := io.ReadFull(r, scratch[:]); err != nil {
return nil, err
}
c.Value = lnwire.MilliSatoshi(byteOrder.Uint64(scratch[:]))
if _, err := io.ReadFull(r, scratch[:]); err != nil {
return nil, err
}
c.CreationDate = time.Unix(int64(byteOrder.Uint64(scratch[:])), 0)
if _, err := io.ReadFull(r, scratch[:4]); err != nil {
return nil, err
}
reqLen := uint32(byteOrder.Uint32(scratch[:4]))
payReq := make([]byte, reqLen)
if reqLen > 0 {
if _, err := io.ReadFull(r, payReq); err != nil {
return nil, err
}
}
c.PaymentRequest = payReq
return c, nil
}
func serializePaymentAttemptInfo(w io.Writer, a *PaymentAttemptInfo) error {
if err := WriteElements(w, a.PaymentID, a.SessionKey); err != nil {
return err
}
if err := SerializeRoute(w, a.Route); err != nil {
return err
}
return nil
}
func deserializePaymentAttemptInfo(r io.Reader) (*PaymentAttemptInfo, error) {
a := &PaymentAttemptInfo{}
err := ReadElements(r, &a.PaymentID, &a.SessionKey)
if err != nil {
return nil, err
}
a.Route, err = DeserializeRoute(r)
if err != nil {
return nil, err
}
return a, nil
}
func serializeHop(w io.Writer, h *route.Hop) error {
if err := WriteElements(w,
h.PubKeyBytes[:],
h.ChannelID,
h.OutgoingTimeLock,
h.AmtToForward,
); err != nil {
return err
}
if err := binary.Write(w, byteOrder, h.LegacyPayload); err != nil {
return err
}
// For legacy payloads, we don't need to write any TLV records, so
// we'll write a zero indicating the our serialized TLV map has no
// records.
if h.LegacyPayload {
return WriteElements(w, uint32(0))
}
// Gather all non-primitive TLV records so that they can be serialized
// as a single blob.
//
// TODO(conner): add migration to unify all fields in a single TLV
// blobs. The split approach will cause headaches down the road as more
// fields are added, which we can avoid by having a single TLV stream
// for all payload fields.
var records []tlv.Record
if h.MPP != nil {
records = append(records, h.MPP.Record())
}
records = append(records, h.TLVRecords...)
// Otherwise, we'll transform our slice of records into a map of the
// raw bytes, then serialize them in-line with a length (number of
// elements) prefix.
mapRecords, err := tlv.RecordsToMap(records)
if err != nil {
return err
}
numRecords := uint32(len(mapRecords))
if err := WriteElements(w, numRecords); err != nil {
return err
}
for recordType, rawBytes := range mapRecords {
if err := WriteElements(w, recordType); err != nil {
return err
}
if err := wire.WriteVarBytes(w, 0, rawBytes); err != nil {
return err
}
}
return nil
}
// maxOnionPayloadSize is the largest Sphinx payload possible, so we don't need
// to read/write a TLV stream larger than this.
const maxOnionPayloadSize = 1300
func deserializeHop(r io.Reader) (*route.Hop, error) {
h := &route.Hop{}
var pub []byte
if err := ReadElements(r, &pub); err != nil {
return nil, err
}
copy(h.PubKeyBytes[:], pub)
if err := ReadElements(r,
&h.ChannelID, &h.OutgoingTimeLock, &h.AmtToForward,
); err != nil {
return nil, err
}
// TODO(roasbeef): change field to allow LegacyPayload false to be the
// legacy default?
err := binary.Read(r, byteOrder, &h.LegacyPayload)
if err != nil {
return nil, err
}
var numElements uint32
if err := ReadElements(r, &numElements); err != nil {
return nil, err
}
// If there're no elements, then we can return early.
if numElements == 0 {
return h, nil
}
tlvMap := make(map[uint64][]byte)
for i := uint32(0); i < numElements; i++ {
var tlvType uint64
if err := ReadElements(r, &tlvType); err != nil {
return nil, err
}
rawRecordBytes, err := wire.ReadVarBytes(
r, 0, maxOnionPayloadSize, "tlv",
)
if err != nil {
return nil, err
}
tlvMap[tlvType] = rawRecordBytes
}
// If the MPP type is present, remove it from the generic TLV map and
// parse it back into a proper MPP struct.
//
// TODO(conner): add migration to unify all fields in a single TLV
// blobs. The split approach will cause headaches down the road as more
// fields are added, which we can avoid by having a single TLV stream
// for all payload fields.
mppType := uint64(record.MPPOnionType)
if mppBytes, ok := tlvMap[mppType]; ok {
delete(tlvMap, mppType)
var (
mpp = &record.MPP{}
mppRec = mpp.Record()
r = bytes.NewReader(mppBytes)
)
err := mppRec.Decode(r, uint64(len(mppBytes)))
if err != nil {
return nil, err
}
h.MPP = mpp
}
tlvRecords, err := tlv.MapToRecords(tlvMap)
if err != nil {
return nil, err
}
h.TLVRecords = tlvRecords
return h, nil
}
// SerializeRoute serializes a route.
func SerializeRoute(w io.Writer, r route.Route) error {
if err := WriteElements(w,
r.TotalTimeLock, r.TotalAmount, r.SourcePubKey[:],
); err != nil {
return err
}
if err := WriteElements(w, uint32(len(r.Hops))); err != nil {
return err
}
for _, h := range r.Hops {
if err := serializeHop(w, h); err != nil {
return err
}
}
return nil
}
// DeserializeRoute deserializes a route.
func DeserializeRoute(r io.Reader) (route.Route, error) {
rt := route.Route{}
if err := ReadElements(r,
&rt.TotalTimeLock, &rt.TotalAmount,
); err != nil {
return rt, err
}
var pub []byte
if err := ReadElements(r, &pub); err != nil {
return rt, err
}
copy(rt.SourcePubKey[:], pub)
var numHops uint32
if err := ReadElements(r, &numHops); err != nil {
return rt, err
}
var hops []*route.Hop
for i := uint32(0); i < numHops; i++ {
hop, err := deserializeHop(r)
if err != nil {
return rt, err
}
hops = append(hops, hop)
}
rt.Hops = hops
return rt, nil
}