lnd.xprv/channeldb/payments.go
2020-05-26 18:21:08 -07:00

910 lines
24 KiB
Go

package channeldb
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
"sort"
"time"
"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/channeldb/kvdb"
"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>
// | |--fail-info-key: <(optional) fail info>
// | |
// | |--payment-htlcs-bucket (shard-bucket)
// | | |
// | | |-- <htlc attempt ID>
// | | | |--htlc-attempt-info-key: <htlc attempt info>
// | | | |--htlc-settle-info-key: <(optional) settle info>
// | | | |--htlc-fail-info-key: <(optional) fail info>
// | | |
// | | |-- <htlc attempt ID>
// | | | |
// | | ... ...
// | |
// | |
// | |--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")
// 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")
// paymentHtlcsBucket is a bucket where we'll store the information
// about the HTLCs that were attempted for a payment.
paymentHtlcsBucket = []byte("payment-htlcs-bucket")
// htlcAttemptInfoKey is a key used in a HTLC's sub-bucket to store the
// info about the attempt that was done for the HTLC in question.
htlcAttemptInfoKey = []byte("htlc-attempt-info")
// htlcSettleInfoKey is a key used in a HTLC's sub-bucket to store the
// settle info, if any.
htlcSettleInfoKey = []byte("htlc-settle-info")
// htlcFailInfoKey is a key used in a HTLC's sub-bucket to store
// failure information, if any.
htlcFailInfoKey = []byte("htlc-fail-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.
)
// Error returns a human readable error string for the FailureReason.
func (r FailureReason) Error() string {
return r.String()
}
// 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
)
// 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
// CreationTime is the time when this payment was initiated.
CreationTime time.Time
// PaymentRequest is the full payment request, if any.
PaymentRequest []byte
}
// FetchPayments returns all sent payments found in the DB.
//
// nolint: dupl
func (db *DB) FetchPayments() ([]*MPPayment, error) {
var payments []*MPPayment
err := kvdb.View(db, func(tx kvdb.RTx) error {
paymentsBucket := tx.ReadBucket(paymentsRootBucket)
if paymentsBucket == nil {
return nil
}
return paymentsBucket.ForEach(func(k, v []byte) error {
bucket := paymentsBucket.NestedReadBucket(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.
duplicatePayments, err := fetchDuplicatePayments(bucket)
if err != nil {
return err
}
payments = append(payments, duplicatePayments...)
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 fetchCreationInfo(bucket kvdb.RBucket) (*PaymentCreationInfo, error) {
b := bucket.Get(paymentCreationInfoKey)
if b == nil {
return nil, fmt.Errorf("creation info not found")
}
r := bytes.NewReader(b)
return deserializePaymentCreationInfo(r)
}
func fetchPayment(bucket kvdb.RBucket) (*MPPayment, error) {
seqBytes := bucket.Get(paymentSequenceKey)
if seqBytes == nil {
return nil, fmt.Errorf("sequence number not found")
}
sequenceNum := binary.BigEndian.Uint64(seqBytes)
// Get the PaymentCreationInfo.
creationInfo, err := fetchCreationInfo(bucket)
if err != nil {
return nil, err
}
var htlcs []HTLCAttempt
htlcsBucket := bucket.NestedReadBucket(paymentHtlcsBucket)
if htlcsBucket != nil {
// Get the payment attempts. This can be empty.
htlcs, err = fetchHtlcAttempts(htlcsBucket)
if err != nil {
return nil, err
}
}
// Get failure reason if available.
var failureReason *FailureReason
b := bucket.Get(paymentFailInfoKey)
if b != nil {
reason := FailureReason(b[0])
failureReason = &reason
}
// Go through all HTLCs for this payment, noting whether we have any
// settled HTLC, and any still in-flight.
var inflight, settled bool
for _, h := range htlcs {
if h.Failure != nil {
continue
}
if h.Settle != nil {
settled = true
continue
}
// If any of the HTLCs are not failed nor settled, we
// still have inflight HTLCs.
inflight = true
}
// Use the DB state to determine the status of the payment.
var paymentStatus PaymentStatus
switch {
// If any of the the HTLCs did succeed and there are no HTLCs in
// flight, the payment succeeded.
case !inflight && settled:
paymentStatus = StatusSucceeded
// If we have no in-flight HTLCs, and the payment failure is set, the
// payment is considered failed.
case !inflight && failureReason != nil:
paymentStatus = StatusFailed
// Otherwise it is still in flight.
default:
paymentStatus = StatusInFlight
}
return &MPPayment{
SequenceNum: sequenceNum,
Info: creationInfo,
HTLCs: htlcs,
FailureReason: failureReason,
Status: paymentStatus,
}, nil
}
// fetchHtlcAttempts retrives all htlc attempts made for the payment found in
// the given bucket.
func fetchHtlcAttempts(bucket kvdb.RBucket) ([]HTLCAttempt, error) {
htlcs := make([]HTLCAttempt, 0)
err := bucket.ForEach(func(k, _ []byte) error {
aid := byteOrder.Uint64(k)
htlcBucket := bucket.NestedReadBucket(k)
attemptInfo, err := fetchHtlcAttemptInfo(
htlcBucket,
)
if err != nil {
return err
}
attemptInfo.AttemptID = aid
htlc := HTLCAttempt{
HTLCAttemptInfo: *attemptInfo,
}
// Settle info might be nil.
htlc.Settle, err = fetchHtlcSettleInfo(htlcBucket)
if err != nil {
return err
}
// Failure info might be nil.
htlc.Failure, err = fetchHtlcFailInfo(htlcBucket)
if err != nil {
return err
}
htlcs = append(htlcs, htlc)
return nil
})
if err != nil {
return nil, err
}
return htlcs, nil
}
// fetchHtlcAttemptInfo fetches the payment attempt info for this htlc from the
// bucket.
func fetchHtlcAttemptInfo(bucket kvdb.RBucket) (*HTLCAttemptInfo, error) {
b := bucket.Get(htlcAttemptInfoKey)
if b == nil {
return nil, errNoAttemptInfo
}
r := bytes.NewReader(b)
return deserializeHTLCAttemptInfo(r)
}
// fetchHtlcSettleInfo retrieves the settle info for the htlc. If the htlc isn't
// settled, nil is returned.
func fetchHtlcSettleInfo(bucket kvdb.RBucket) (*HTLCSettleInfo, error) {
b := bucket.Get(htlcSettleInfoKey)
if b == nil {
// Settle info is optional.
return nil, nil
}
r := bytes.NewReader(b)
return deserializeHTLCSettleInfo(r)
}
// fetchHtlcFailInfo retrieves the failure info for the htlc. If the htlc hasn't
// failed, nil is returned.
func fetchHtlcFailInfo(bucket kvdb.RBucket) (*HTLCFailInfo, error) {
b := bucket.Get(htlcFailInfoKey)
if b == nil {
// Fail info is optional.
return nil, nil
}
r := bytes.NewReader(b)
return deserializeHTLCFailInfo(r)
}
// PaymentsQuery represents a query to the payments database starting or ending
// at a certain offset index. The number of retrieved records can be limited.
type PaymentsQuery struct {
// IndexOffset determines the starting point of the payments query and
// is always exclusive. In normal order, the query starts at the next
// higher (available) index compared to IndexOffset. In reversed order,
// the query ends at the next lower (available) index compared to the
// IndexOffset. In the case of a zero index_offset, the query will start
// with the oldest payment when paginating forwards, or will end with
// the most recent payment when paginating backwards.
IndexOffset uint64
// MaxPayments is the maximal number of payments returned in the
// payments query.
MaxPayments uint64
// Reversed gives a meaning to the IndexOffset. If reversed is set to
// true, the query will fetch payments with indices lower than the
// IndexOffset, otherwise, it will return payments with indices greater
// than the IndexOffset.
Reversed bool
// If IncludeIncomplete is true, then return payments that have not yet
// fully completed. This means that pending payments, as well as failed
// payments will show up if this field is set to true.
IncludeIncomplete bool
}
// PaymentsResponse contains the result of a query to the payments database.
// It includes the set of payments that match the query and integers which
// represent the index of the first and last item returned in the series of
// payments. These integers allow callers to resume their query in the event
// that the query's response exceeds the max number of returnable events.
type PaymentsResponse struct {
// Payments is the set of payments returned from the database for the
// PaymentsQuery.
Payments []*MPPayment
// FirstIndexOffset is the index of the first element in the set of
// returned MPPayments. Callers can use this to resume their query
// in the event that the slice has too many events to fit into a single
// response. The offset can be used to continue reverse pagination.
FirstIndexOffset uint64
// LastIndexOffset is the index of the last element in the set of
// returned MPPayments. Callers can use this to resume their query
// in the event that the slice has too many events to fit into a single
// response. The offset can be used to continue forward pagination.
LastIndexOffset uint64
}
// QueryPayments is a query to the payments database which is restricted
// to a subset of payments by the payments query, containing an offset
// index and a maximum number of returned payments.
func (db *DB) QueryPayments(query PaymentsQuery) (PaymentsResponse, error) {
var resp PaymentsResponse
allPayments, err := db.FetchPayments()
if err != nil {
return resp, err
}
if len(allPayments) == 0 {
return resp, nil
}
indexExclusiveLimit := query.IndexOffset
// In backward pagination, if the index limit is the default 0 value,
// we set our limit to maxint to include all payments from the highest
// sequence number on.
if query.Reversed && indexExclusiveLimit == 0 {
indexExclusiveLimit = math.MaxInt64
}
for i := range allPayments {
var payment *MPPayment
// If we have the max number of payments we want, exit.
if uint64(len(resp.Payments)) == query.MaxPayments {
break
}
if query.Reversed {
payment = allPayments[len(allPayments)-1-i]
// In the reversed direction, skip over all payments
// that have sequence numbers greater than or equal to
// the index offset. We skip payments with equal index
// because the offset is exclusive.
if payment.SequenceNum >= indexExclusiveLimit {
continue
}
} else {
payment = allPayments[i]
// In the forward direction, skip over all payments that
// have sequence numbers less than or equal to the index
// offset. We skip payments with equal indexes because
// the index offset is exclusive.
if payment.SequenceNum <= indexExclusiveLimit {
continue
}
}
// To keep compatibility with the old API, we only return
// non-succeeded payments if requested.
if payment.Status != StatusSucceeded &&
!query.IncludeIncomplete {
continue
}
resp.Payments = append(resp.Payments, payment)
}
// Need to swap the payments slice order if reversed order.
if query.Reversed {
for l, r := 0, len(resp.Payments)-1; l < r; l, r = l+1, r-1 {
resp.Payments[l], resp.Payments[r] =
resp.Payments[r], resp.Payments[l]
}
}
// Set the first and last index of the returned payments so that the
// caller can resume from this point later on.
if len(resp.Payments) > 0 {
resp.FirstIndexOffset = resp.Payments[0].SequenceNum
resp.LastIndexOffset =
resp.Payments[len(resp.Payments)-1].SequenceNum
}
return resp, err
}
// DeletePayments deletes all completed and failed payments from the DB.
func (db *DB) DeletePayments() error {
return kvdb.Update(db, func(tx kvdb.RwTx) error {
payments := tx.ReadWriteBucket(paymentsRootBucket)
if payments == nil {
return nil
}
var deleteBuckets [][]byte
err := payments.ForEach(func(k, _ []byte) error {
bucket := payments.NestedReadWriteBucket(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, err := fetchPaymentStatus(bucket)
if err != nil {
return err
}
// If the status is InFlight, we cannot safely delete
// the payment information, so we return early.
if paymentStatus == StatusInFlight {
return nil
}
deleteBuckets = append(deleteBuckets, k)
return nil
})
if err != nil {
return err
}
for _, k := range deleteBuckets {
if err := payments.DeleteNestedBucket(k); err != nil {
return err
}
}
return nil
})
}
// nolint: dupl
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
}
if err := serializeTime(w, c.CreationTime); 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[:]))
creationTime, err := deserializeTime(r)
if err != nil {
return nil, err
}
c.CreationTime = creationTime
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 serializeHTLCAttemptInfo(w io.Writer, a *HTLCAttemptInfo) error {
if err := WriteElements(w, a.SessionKey); err != nil {
return err
}
if err := SerializeRoute(w, a.Route); err != nil {
return err
}
return serializeTime(w, a.AttemptTime)
}
func deserializeHTLCAttemptInfo(r io.Reader) (*HTLCAttemptInfo, error) {
a := &HTLCAttemptInfo{}
err := ReadElements(r, &a.SessionKey)
if err != nil {
return nil, err
}
a.Route, err = DeserializeRoute(r)
if err != nil {
return nil, err
}
a.AttemptTime, err = deserializeTime(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())
}
// Final sanity check to absolutely rule out custom records that are not
// custom and write into the standard range.
if err := h.CustomRecords.Validate(); err != nil {
return err
}
// Convert custom records to tlv and add to the record list.
// MapToRecords sorts the list, so adding it here will keep the list
// canonical.
tlvRecords := tlv.MapToRecords(h.CustomRecords)
records = append(records, 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
}
h.CustomRecords = tlvMap
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
}