package channeldb import ( "bytes" "encoding/binary" "io" "github.com/coreos/bbolt" "github.com/lightningnetwork/lnd/lnwire" ) var ( // paymentBucket is the name of the bucket within the database that // stores all data related to payments. // // Within the payments bucket, each invoice is keyed by its invoice ID // which is a monotonically increasing uint64. BoltDB's sequence // feature is used for generating monotonically increasing id. paymentBucket = []byte("payments") ) // OutgoingPayment represents a successful payment between the daemon and a // remote node. Details such as the total fee paid, and the time of the payment // are stored. type OutgoingPayment struct { Invoice // Fee is the total fee paid for the payment in milli-satoshis. Fee lnwire.MilliSatoshi // TotalTimeLock is the total cumulative time-lock in the HTLC extended // from the second-to-last hop to the destination. TimeLockLength uint32 // Path encodes the path the payment took through the network. The path // excludes the outgoing node and consists of the hex-encoded // compressed public key of each of the nodes involved in the payment. Path [][33]byte // PaymentPreimage is the preImage of a successful payment. This is used // to calculate the PaymentHash as well as serve as a proof of payment. PaymentPreimage [32]byte } // AddPayment saves a successful payment to the database. It is assumed that // all payment are sent using unique payment hashes. func (db *DB) AddPayment(payment *OutgoingPayment) error { // Validate the field of the inner voice within the outgoing payment, // these must also adhere to the same constraints as regular invoices. if err := validateInvoice(&payment.Invoice); err != nil { return err } // We first serialize the payment before starting the database // transaction so we can avoid creating a DB payment in the case of a // serialization error. var b bytes.Buffer if err := serializeOutgoingPayment(&b, payment); err != nil { return err } paymentBytes := b.Bytes() return db.Batch(func(tx *bolt.Tx) error { payments, err := tx.CreateBucketIfNotExists(paymentBucket) if err != nil { return err } // Obtain the new unique sequence number for this payment. paymentID, err := payments.NextSequence() if err != nil { return err } // We use BigEndian for keys as it orders keys in // ascending order. This allows bucket scans to order payments // in the order in which they were created. paymentIDBytes := make([]byte, 8) binary.BigEndian.PutUint64(paymentIDBytes, paymentID) return payments.Put(paymentIDBytes, paymentBytes) }) } // FetchAllPayments returns all outgoing payments in DB. func (db *DB) FetchAllPayments() ([]*OutgoingPayment, error) { var payments []*OutgoingPayment err := db.View(func(tx *bolt.Tx) error { bucket := tx.Bucket(paymentBucket) if bucket == nil { return ErrNoPaymentsCreated } return bucket.ForEach(func(k, v []byte) error { // If the value is nil, then we ignore it as it may be // a sub-bucket. if v == nil { return nil } r := bytes.NewReader(v) payment, err := deserializeOutgoingPayment(r) if err != nil { return err } payments = append(payments, payment) return nil }) }) if err != nil { return nil, err } return payments, nil } // DeleteAllPayments deletes all payments from DB. func (db *DB) DeleteAllPayments() error { return db.Update(func(tx *bolt.Tx) error { err := tx.DeleteBucket(paymentBucket) if err != nil && err != bolt.ErrBucketNotFound { return err } _, err = tx.CreateBucket(paymentBucket) return err }) } func serializeOutgoingPayment(w io.Writer, p *OutgoingPayment) error { var scratch [8]byte if err := serializeInvoice(w, &p.Invoice); err != nil { return err } byteOrder.PutUint64(scratch[:], uint64(p.Fee)) if _, err := w.Write(scratch[:]); err != nil { return err } // First write out the length of the bytes to prefix the value. pathLen := uint32(len(p.Path)) byteOrder.PutUint32(scratch[:4], pathLen) if _, err := w.Write(scratch[:4]); err != nil { return err } // Then with the path written, we write out the series of public keys // involved in the path. for _, hop := range p.Path { if _, err := w.Write(hop[:]); err != nil { return err } } byteOrder.PutUint32(scratch[:4], p.TimeLockLength) if _, err := w.Write(scratch[:4]); err != nil { return err } if _, err := w.Write(p.PaymentPreimage[:]); err != nil { return err } return nil } func deserializeOutgoingPayment(r io.Reader) (*OutgoingPayment, error) { var scratch [8]byte p := &OutgoingPayment{} inv, err := deserializeInvoice(r) if err != nil { return nil, err } p.Invoice = *inv if _, err := r.Read(scratch[:]); err != nil { return nil, err } p.Fee = lnwire.MilliSatoshi(byteOrder.Uint64(scratch[:])) if _, err = r.Read(scratch[:4]); err != nil { return nil, err } pathLen := byteOrder.Uint32(scratch[:4]) path := make([][33]byte, pathLen) for i := uint32(0); i < pathLen; i++ { if _, err := r.Read(path[i][:]); err != nil { return nil, err } } p.Path = path if _, err = r.Read(scratch[:4]); err != nil { return nil, err } p.TimeLockLength = byteOrder.Uint32(scratch[:4]) if _, err := r.Read(p.PaymentPreimage[:]); err != nil { return nil, err } return p, nil }