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 // | // |-- // | |--sequence-key: // | |--creation-info-key: // | |--fail-info-key: <(optional) fail info> // | | // | |--payment-htlcs-bucket (shard-bucket) // | | | // | | |-- // | | | |--htlc-attempt-info-key: // | | | |--htlc-settle-info-key: <(optional) settle info> // | | | |--htlc-fail-info-key: <(optional) fail info> // | | | // | | |-- // | | | | // | | ... ... // | | // | | // | |--duplicate-bucket (only for old, completed payments) // | | // | |-- // | | |--sequence-key: // | | |--creation-info-key: // | | |--attempt-info-key: // | | |--settle-info-key: // | | |--fail-info-key: // | | // | |-- // | | | // | ... ... // | // |-- // | | // | ... // ... // 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. // // This reason isn't assigned anymore, but may still exist for older // payments. 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.ReadTx) 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.ReadBucket) (*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.ReadBucket) (*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.ReadBucket) ([]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.ReadBucket) (*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.ReadBucket) (*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.ReadBucket) (*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 }