package channeldb import ( "bytes" "encoding/binary" "errors" "fmt" "io" "time" "github.com/coreos/bbolt" "github.com/lightningnetwork/lnd/htlcswitch/hop" "github.com/lightningnetwork/lnd/lntypes" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/tlv" ) var ( // UnknownPreimage is an all-zeroes preimage that indicates that the // preimage for this invoice is not yet known. UnknownPreimage lntypes.Preimage // invoiceBucket is the name of the bucket within the database that // stores all data related to invoices no matter their final state. // Within the invoice bucket, each invoice is keyed by its invoice ID // which is a monotonically increasing uint32. invoiceBucket = []byte("invoices") // paymentHashIndexBucket is the name of the sub-bucket within the // invoiceBucket which indexes all invoices by their payment hash. The // payment hash is the sha256 of the invoice's payment preimage. This // index is used to detect duplicates, and also to provide a fast path // for looking up incoming HTLCs to determine if we're able to settle // them fully. // // maps: payHash => invoiceKey invoiceIndexBucket = []byte("paymenthashes") // numInvoicesKey is the name of key which houses the auto-incrementing // invoice ID which is essentially used as a primary key. With each // invoice inserted, the primary key is incremented by one. This key is // stored within the invoiceIndexBucket. Within the invoiceBucket // invoices are uniquely identified by the invoice ID. numInvoicesKey = []byte("nik") // addIndexBucket is an index bucket that we'll use to create a // monotonically increasing set of add indexes. Each time we add a new // invoice, this sequence number will be incremented and then populated // within the new invoice. // // In addition to this sequence number, we map: // // addIndexNo => invoiceKey addIndexBucket = []byte("invoice-add-index") // settleIndexBucket is an index bucket that we'll use to create a // monotonically increasing integer for tracking a "settle index". Each // time an invoice is settled, this sequence number will be incremented // as populate within the newly settled invoice. // // In addition to this sequence number, we map: // // settleIndexNo => invoiceKey settleIndexBucket = []byte("invoice-settle-index") // ErrInvoiceAlreadySettled is returned when the invoice is already // settled. ErrInvoiceAlreadySettled = errors.New("invoice already settled") // ErrInvoiceAlreadyCanceled is returned when the invoice is already // canceled. ErrInvoiceAlreadyCanceled = errors.New("invoice already canceled") // ErrInvoiceAlreadyAccepted is returned when the invoice is already // accepted. ErrInvoiceAlreadyAccepted = errors.New("invoice already accepted") // ErrInvoiceStillOpen is returned when the invoice is still open. ErrInvoiceStillOpen = errors.New("invoice still open") // ErrInvoiceCannotOpen is returned when an attempt is made to move an // invoice to the open state. ErrInvoiceCannotOpen = errors.New("cannot move invoice to open") // ErrInvoiceCannotAccept is returned when an attempt is made to accept // an invoice while the invoice is not in the open state. ErrInvoiceCannotAccept = errors.New("cannot accept invoice") // ErrInvoicePreimageMismatch is returned when the preimage doesn't // match the invoice hash. ErrInvoicePreimageMismatch = errors.New("preimage does not match") ) const ( // MaxMemoSize is maximum size of the memo field within invoices stored // in the database. MaxMemoSize = 1024 // MaxPaymentRequestSize is the max size of a payment request for // this invoice. // TODO(halseth): determine the max length payment request when field // lengths are final. MaxPaymentRequestSize = 4096 // A set of tlv type definitions used to serialize invoice htlcs to the // database. // // NOTE: A migration should be added whenever this list changes. This // prevents against the database being rolled back to an older // format where the surrounding logic might assume a different set of // fields are known. chanIDType tlv.Type = 1 htlcIDType tlv.Type = 3 amtType tlv.Type = 5 acceptHeightType tlv.Type = 7 acceptTimeType tlv.Type = 9 resolveTimeType tlv.Type = 11 expiryHeightType tlv.Type = 13 htlcStateType tlv.Type = 15 mppTotalAmtType tlv.Type = 17 // A set of tlv type definitions used to serialize invoice bodiees. // // NOTE: A migration should be added whenever this list changes. This // prevents against the database being rolled back to an older // format where the surrounding logic might assume a different set of // fields are known. memoType tlv.Type = 0 payReqType tlv.Type = 1 createTimeType tlv.Type = 2 settleTimeType tlv.Type = 3 addIndexType tlv.Type = 4 settleIndexType tlv.Type = 5 preimageType tlv.Type = 6 valueType tlv.Type = 7 cltvDeltaType tlv.Type = 8 expiryType tlv.Type = 9 paymentAddrType tlv.Type = 10 featuresType tlv.Type = 11 invStateType tlv.Type = 12 amtPaidType tlv.Type = 13 ) // ContractState describes the state the invoice is in. type ContractState uint8 const ( // ContractOpen means the invoice has only been created. ContractOpen ContractState = 0 // ContractSettled means the htlc is settled and the invoice has been // paid. ContractSettled ContractState = 1 // ContractCanceled means the invoice has been canceled. ContractCanceled ContractState = 2 // ContractAccepted means the HTLC has been accepted but not settled // yet. ContractAccepted ContractState = 3 ) // String returns a human readable identifier for the ContractState type. func (c ContractState) String() string { switch c { case ContractOpen: return "Open" case ContractSettled: return "Settled" case ContractCanceled: return "Canceled" case ContractAccepted: return "Accepted" } return "Unknown" } // ContractTerm is a companion struct to the Invoice struct. This struct houses // the necessary conditions required before the invoice can be considered fully // settled by the payee. type ContractTerm struct { // FinalCltvDelta is the minimum required number of blocks before htlc // expiry when the invoice is accepted. FinalCltvDelta int32 // Expiry defines how long after creation this invoice should expire. Expiry time.Duration // PaymentPreimage is the preimage which is to be revealed in the // occasion that an HTLC paying to the hash of this preimage is // extended. PaymentPreimage lntypes.Preimage // Value is the expected amount of milli-satoshis to be paid to an HTLC // which can be satisfied by the above preimage. Value lnwire.MilliSatoshi // PaymentAddr is a randomly generated value include in the MPP record // by the sender to prevent probing of the receiver. PaymentAddr [32]byte // Features is the feature vectors advertised on the payment request. Features *lnwire.FeatureVector } // Invoice is a payment invoice generated by a payee in order to request // payment for some good or service. The inclusion of invoices within Lightning // creates a payment work flow for merchants very similar to that of the // existing financial system within PayPal, etc. Invoices are added to the // database when a payment is requested, then can be settled manually once the // payment is received at the upper layer. For record keeping purposes, // invoices are never deleted from the database, instead a bit is toggled // denoting the invoice has been fully settled. Within the database, all // invoices must have a unique payment hash which is generated by taking the // sha256 of the payment preimage. type Invoice struct { // Memo is an optional memo to be stored along side an invoice. The // memo may contain further details pertaining to the invoice itself, // or any other message which fits within the size constraints. Memo []byte // PaymentRequest is an optional field where a payment request created // for this invoice can be stored. PaymentRequest []byte // CreationDate is the exact time the invoice was created. CreationDate time.Time // SettleDate is the exact time the invoice was settled. SettleDate time.Time // Terms are the contractual payment terms of the invoice. Once all the // terms have been satisfied by the payer, then the invoice can be // considered fully fulfilled. // // TODO(roasbeef): later allow for multiple terms to fulfill the final // invoice: payment fragmentation, etc. Terms ContractTerm // AddIndex is an auto-incrementing integer that acts as a // monotonically increasing sequence number for all invoices created. // Clients can then use this field as a "checkpoint" of sorts when // implementing a streaming RPC to notify consumers of instances where // an invoice has been added before they re-connected. // // NOTE: This index starts at 1. AddIndex uint64 // SettleIndex is an auto-incrementing integer that acts as a // monotonically increasing sequence number for all settled invoices. // Clients can then use this field as a "checkpoint" of sorts when // implementing a streaming RPC to notify consumers of instances where // an invoice has been settled before they re-connected. // // NOTE: This index starts at 1. SettleIndex uint64 // State describes the state the invoice is in. State ContractState // AmtPaid is the final amount that we ultimately accepted for pay for // this invoice. We specify this value independently as it's possible // that the invoice originally didn't specify an amount, or the sender // overpaid. AmtPaid lnwire.MilliSatoshi // Htlcs records all htlcs that paid to this invoice. Some of these // htlcs may have been marked as canceled. Htlcs map[CircuitKey]*InvoiceHTLC } // HtlcState defines the states an htlc paying to an invoice can be in. type HtlcState uint8 const ( // HtlcStateAccepted indicates the htlc is locked-in, but not resolved. HtlcStateAccepted HtlcState = iota // HtlcStateCanceled indicates the htlc is canceled back to the // sender. HtlcStateCanceled // HtlcStateSettled indicates the htlc is settled. HtlcStateSettled ) // InvoiceHTLC contains details about an htlc paying to this invoice. type InvoiceHTLC struct { // Amt is the amount that is carried by this htlc. Amt lnwire.MilliSatoshi // MppTotalAmt is a field for mpp that indicates the expected total // amount. MppTotalAmt lnwire.MilliSatoshi // AcceptHeight is the block height at which the invoice registry // decided to accept this htlc as a payment to the invoice. At this // height, the invoice cltv delay must have been met. AcceptHeight uint32 // AcceptTime is the wall clock time at which the invoice registry // decided to accept the htlc. AcceptTime time.Time // ResolveTime is the wall clock time at which the invoice registry // decided to settle the htlc. ResolveTime time.Time // Expiry is the expiry height of this htlc. Expiry uint32 // State indicates the state the invoice htlc is currently in. A // canceled htlc isn't just removed from the invoice htlcs map, because // we need AcceptHeight to properly cancel the htlc back. State HtlcState // CustomRecords contains the custom key/value pairs that accompanied // the htlc. CustomRecords hop.CustomRecordSet } // HtlcAcceptDesc describes the details of a newly accepted htlc. type HtlcAcceptDesc struct { // AcceptHeight is the block height at which this htlc was accepted. AcceptHeight int32 // Amt is the amount that is carried by this htlc. Amt lnwire.MilliSatoshi // MppTotalAmt is a field for mpp that indicates the expected total // amount. MppTotalAmt lnwire.MilliSatoshi // Expiry is the expiry height of this htlc. Expiry uint32 // CustomRecords contains the custom key/value pairs that accompanied // the htlc. CustomRecords hop.CustomRecordSet } // InvoiceUpdateDesc describes the changes that should be applied to the // invoice. type InvoiceUpdateDesc struct { // State is the new state that this invoice should progress to. If nil, // the state is left unchanged. State *InvoiceStateUpdateDesc // CancelHtlcs describes the htlcs that need to be canceled. CancelHtlcs map[CircuitKey]struct{} // AddHtlcs describes the newly accepted htlcs that need to be added to // the invoice. AddHtlcs map[CircuitKey]*HtlcAcceptDesc } // InvoiceStateUpdateDesc describes an invoice-level state transition. type InvoiceStateUpdateDesc struct { // NewState is the new state that this invoice should progress to. NewState ContractState // Preimage must be set to the preimage when NewState is settled. Preimage lntypes.Preimage } // InvoiceUpdateCallback is a callback used in the db transaction to update the // invoice. type InvoiceUpdateCallback = func(invoice *Invoice) (*InvoiceUpdateDesc, error) func validateInvoice(i *Invoice) error { if len(i.Memo) > MaxMemoSize { return fmt.Errorf("max length a memo is %v, and invoice "+ "of length %v was provided", MaxMemoSize, len(i.Memo)) } if len(i.PaymentRequest) > MaxPaymentRequestSize { return fmt.Errorf("max length of payment request is %v, length "+ "provided was %v", MaxPaymentRequestSize, len(i.PaymentRequest)) } if i.Terms.Features == nil { return errors.New("invoice must have a feature vector") } return nil } // AddInvoice inserts the targeted invoice into the database. If the invoice has // *any* payment hashes which already exists within the database, then the // insertion will be aborted and rejected due to the strict policy banning any // duplicate payment hashes. A side effect of this function is that it sets // AddIndex on newInvoice. func (d *DB) AddInvoice(newInvoice *Invoice, paymentHash lntypes.Hash) ( uint64, error) { if err := validateInvoice(newInvoice); err != nil { return 0, err } var invoiceAddIndex uint64 err := d.Update(func(tx *bbolt.Tx) error { invoices, err := tx.CreateBucketIfNotExists(invoiceBucket) if err != nil { return err } invoiceIndex, err := invoices.CreateBucketIfNotExists( invoiceIndexBucket, ) if err != nil { return err } addIndex, err := invoices.CreateBucketIfNotExists( addIndexBucket, ) if err != nil { return err } // Ensure that an invoice an identical payment hash doesn't // already exist within the index. if invoiceIndex.Get(paymentHash[:]) != nil { return ErrDuplicateInvoice } // If the current running payment ID counter hasn't yet been // created, then create it now. var invoiceNum uint32 invoiceCounter := invoiceIndex.Get(numInvoicesKey) if invoiceCounter == nil { var scratch [4]byte byteOrder.PutUint32(scratch[:], invoiceNum) err := invoiceIndex.Put(numInvoicesKey, scratch[:]) if err != nil { return err } } else { invoiceNum = byteOrder.Uint32(invoiceCounter) } newIndex, err := putInvoice( invoices, invoiceIndex, addIndex, newInvoice, invoiceNum, paymentHash, ) if err != nil { return err } invoiceAddIndex = newIndex return nil }) if err != nil { return 0, err } return invoiceAddIndex, err } // InvoicesAddedSince can be used by callers to seek into the event time series // of all the invoices added in the database. The specified sinceAddIndex // should be the highest add index that the caller knows of. This method will // return all invoices with an add index greater than the specified // sinceAddIndex. // // NOTE: The index starts from 1, as a result. We enforce that specifying a // value below the starting index value is a noop. func (d *DB) InvoicesAddedSince(sinceAddIndex uint64) ([]Invoice, error) { var newInvoices []Invoice // If an index of zero was specified, then in order to maintain // backwards compat, we won't send out any new invoices. if sinceAddIndex == 0 { return newInvoices, nil } var startIndex [8]byte byteOrder.PutUint64(startIndex[:], sinceAddIndex) err := d.DB.View(func(tx *bbolt.Tx) error { invoices := tx.Bucket(invoiceBucket) if invoices == nil { return ErrNoInvoicesCreated } addIndex := invoices.Bucket(addIndexBucket) if addIndex == nil { return ErrNoInvoicesCreated } // We'll now run through each entry in the add index starting // at our starting index. We'll continue until we reach the // very end of the current key space. invoiceCursor := addIndex.Cursor() // We'll seek to the starting index, then manually advance the // cursor in order to skip the entry with the since add index. invoiceCursor.Seek(startIndex[:]) addSeqNo, invoiceKey := invoiceCursor.Next() for ; addSeqNo != nil && bytes.Compare(addSeqNo, startIndex[:]) > 0; addSeqNo, invoiceKey = invoiceCursor.Next() { // For each key found, we'll look up the actual // invoice, then accumulate it into our return value. invoice, err := fetchInvoice(invoiceKey, invoices) if err != nil { return err } newInvoices = append(newInvoices, invoice) } return nil }) switch { // If no invoices have been created, then we'll return the empty set of // invoices. case err == ErrNoInvoicesCreated: case err != nil: return nil, err } return newInvoices, nil } // LookupInvoice attempts to look up an invoice according to its 32 byte // payment hash. If an invoice which can settle the HTLC identified by the // passed payment hash isn't found, then an error is returned. Otherwise, the // full invoice is returned. Before setting the incoming HTLC, the values // SHOULD be checked to ensure the payer meets the agreed upon contractual // terms of the payment. func (d *DB) LookupInvoice(paymentHash [32]byte) (Invoice, error) { var invoice Invoice err := d.View(func(tx *bbolt.Tx) error { invoices := tx.Bucket(invoiceBucket) if invoices == nil { return ErrNoInvoicesCreated } invoiceIndex := invoices.Bucket(invoiceIndexBucket) if invoiceIndex == nil { return ErrNoInvoicesCreated } // Check the invoice index to see if an invoice paying to this // hash exists within the DB. invoiceNum := invoiceIndex.Get(paymentHash[:]) if invoiceNum == nil { return ErrInvoiceNotFound } // An invoice matching the payment hash has been found, so // retrieve the record of the invoice itself. i, err := fetchInvoice(invoiceNum, invoices) if err != nil { return err } invoice = i return nil }) if err != nil { return invoice, err } return invoice, nil } // FetchAllInvoices returns all invoices currently stored within the database. // If the pendingOnly param is true, then only unsettled invoices will be // returned, skipping all invoices that are fully settled. func (d *DB) FetchAllInvoices(pendingOnly bool) ([]Invoice, error) { var invoices []Invoice err := d.View(func(tx *bbolt.Tx) error { invoiceB := tx.Bucket(invoiceBucket) if invoiceB == nil { return ErrNoInvoicesCreated } // Iterate through the entire key space of the top-level // invoice bucket. If key with a non-nil value stores the next // invoice ID which maps to the corresponding invoice. return invoiceB.ForEach(func(k, v []byte) error { if v == nil { return nil } invoiceReader := bytes.NewReader(v) invoice, err := deserializeInvoice(invoiceReader) if err != nil { return err } if pendingOnly && invoice.State == ContractSettled { return nil } invoices = append(invoices, invoice) return nil }) }) if err != nil { return nil, err } return invoices, nil } // InvoiceQuery represents a query to the invoice database. The query allows a // caller to retrieve all invoices starting from a particular add index and // limit the number of results returned. type InvoiceQuery struct { // IndexOffset is the offset within the add indices to start at. This // can be used to start the response at a particular invoice. IndexOffset uint64 // NumMaxInvoices is the maximum number of invoices that should be // starting from the add index. NumMaxInvoices uint64 // PendingOnly, if set, returns unsettled invoices starting from the // add index. PendingOnly bool // Reversed, if set, indicates that the invoices returned should start // from the IndexOffset and go backwards. Reversed bool } // InvoiceSlice is the response to a invoice query. It includes the original // query, the set of invoices that match the query, and an integer which // represents the offset index of the last item in the set of returned invoices. // This integer allows callers to resume their query using this offset in the // event that the query's response exceeds the maximum number of returnable // invoices. type InvoiceSlice struct { InvoiceQuery // Invoices is the set of invoices that matched the query above. Invoices []Invoice // FirstIndexOffset is the index of the first element in the set of // returned Invoices above. Callers can use this to resume their query // in the event that the slice has too many events to fit into a single // response. FirstIndexOffset uint64 // LastIndexOffset is the index of the last element in the set of // returned Invoices above. Callers can use this to resume their query // in the event that the slice has too many events to fit into a single // response. LastIndexOffset uint64 } // QueryInvoices allows a caller to query the invoice database for invoices // within the specified add index range. func (d *DB) QueryInvoices(q InvoiceQuery) (InvoiceSlice, error) { resp := InvoiceSlice{ InvoiceQuery: q, } err := d.View(func(tx *bbolt.Tx) error { // If the bucket wasn't found, then there aren't any invoices // within the database yet, so we can simply exit. invoices := tx.Bucket(invoiceBucket) if invoices == nil { return ErrNoInvoicesCreated } invoiceAddIndex := invoices.Bucket(addIndexBucket) if invoiceAddIndex == nil { return ErrNoInvoicesCreated } // keyForIndex is a helper closure that retrieves the invoice // key for the given add index of an invoice. keyForIndex := func(c *bbolt.Cursor, index uint64) []byte { var keyIndex [8]byte byteOrder.PutUint64(keyIndex[:], index) _, invoiceKey := c.Seek(keyIndex[:]) return invoiceKey } // nextKey is a helper closure to determine what the next // invoice key is when iterating over the invoice add index. nextKey := func(c *bbolt.Cursor) ([]byte, []byte) { if q.Reversed { return c.Prev() } return c.Next() } // We'll be using a cursor to seek into the database and return // a slice of invoices. We'll need to determine where to start // our cursor depending on the parameters set within the query. c := invoiceAddIndex.Cursor() invoiceKey := keyForIndex(c, q.IndexOffset+1) // If the query is specifying reverse iteration, then we must // handle a few offset cases. if q.Reversed { switch q.IndexOffset { // This indicates the default case, where no offset was // specified. In that case we just start from the last // invoice. case 0: _, invoiceKey = c.Last() // This indicates the offset being set to the very // first invoice. Since there are no invoices before // this offset, and the direction is reversed, we can // return without adding any invoices to the response. case 1: return nil // Otherwise we start iteration at the invoice prior to // the offset. default: invoiceKey = keyForIndex(c, q.IndexOffset-1) } } // If we know that a set of invoices exists, then we'll begin // our seek through the bucket in order to satisfy the query. // We'll continue until either we reach the end of the range, or // reach our max number of invoices. for ; invoiceKey != nil; _, invoiceKey = nextKey(c) { // If our current return payload exceeds the max number // of invoices, then we'll exit now. if uint64(len(resp.Invoices)) >= q.NumMaxInvoices { break } invoice, err := fetchInvoice(invoiceKey, invoices) if err != nil { return err } // Skip any settled invoices if the caller is only // interested in unsettled. if q.PendingOnly && invoice.State == ContractSettled { continue } // At this point, we've exhausted the offset, so we'll // begin collecting invoices found within the range. resp.Invoices = append(resp.Invoices, invoice) } // If we iterated through the add index in reverse order, then // we'll need to reverse the slice of invoices to return them in // forward order. if q.Reversed { numInvoices := len(resp.Invoices) for i := 0; i < numInvoices/2; i++ { opposite := numInvoices - i - 1 resp.Invoices[i], resp.Invoices[opposite] = resp.Invoices[opposite], resp.Invoices[i] } } return nil }) if err != nil && err != ErrNoInvoicesCreated { return resp, err } // Finally, record the indexes of the first and last invoices returned // so that the caller can resume from this point later on. if len(resp.Invoices) > 0 { resp.FirstIndexOffset = resp.Invoices[0].AddIndex resp.LastIndexOffset = resp.Invoices[len(resp.Invoices)-1].AddIndex } return resp, nil } // UpdateInvoice attempts to update an invoice corresponding to the passed // payment hash. If an invoice matching the passed payment hash doesn't exist // within the database, then the action will fail with a "not found" error. // // The update is performed inside the same database transaction that fetches the // invoice and is therefore atomic. The fields to update are controlled by the // supplied callback. func (d *DB) UpdateInvoice(paymentHash lntypes.Hash, callback InvoiceUpdateCallback) (*Invoice, error) { var updatedInvoice *Invoice err := d.Update(func(tx *bbolt.Tx) error { invoices, err := tx.CreateBucketIfNotExists(invoiceBucket) if err != nil { return err } invoiceIndex, err := invoices.CreateBucketIfNotExists( invoiceIndexBucket, ) if err != nil { return err } settleIndex, err := invoices.CreateBucketIfNotExists( settleIndexBucket, ) if err != nil { return err } // Check the invoice index to see if an invoice paying to this // hash exists within the DB. invoiceNum := invoiceIndex.Get(paymentHash[:]) if invoiceNum == nil { return ErrInvoiceNotFound } updatedInvoice, err = d.updateInvoice( paymentHash, invoices, settleIndex, invoiceNum, callback, ) return err }) return updatedInvoice, err } // InvoicesSettledSince can be used by callers to catch up any settled invoices // they missed within the settled invoice time series. We'll return all known // settled invoice that have a settle index higher than the passed // sinceSettleIndex. // // NOTE: The index starts from 1, as a result. We enforce that specifying a // value below the starting index value is a noop. func (d *DB) InvoicesSettledSince(sinceSettleIndex uint64) ([]Invoice, error) { var settledInvoices []Invoice // If an index of zero was specified, then in order to maintain // backwards compat, we won't send out any new invoices. if sinceSettleIndex == 0 { return settledInvoices, nil } var startIndex [8]byte byteOrder.PutUint64(startIndex[:], sinceSettleIndex) err := d.DB.View(func(tx *bbolt.Tx) error { invoices := tx.Bucket(invoiceBucket) if invoices == nil { return ErrNoInvoicesCreated } settleIndex := invoices.Bucket(settleIndexBucket) if settleIndex == nil { return ErrNoInvoicesCreated } // We'll now run through each entry in the add index starting // at our starting index. We'll continue until we reach the // very end of the current key space. invoiceCursor := settleIndex.Cursor() // We'll seek to the starting index, then manually advance the // cursor in order to skip the entry with the since add index. invoiceCursor.Seek(startIndex[:]) seqNo, invoiceKey := invoiceCursor.Next() for ; seqNo != nil && bytes.Compare(seqNo, startIndex[:]) > 0; seqNo, invoiceKey = invoiceCursor.Next() { // For each key found, we'll look up the actual // invoice, then accumulate it into our return value. invoice, err := fetchInvoice(invoiceKey, invoices) if err != nil { return err } settledInvoices = append(settledInvoices, invoice) } return nil }) if err != nil { return nil, err } return settledInvoices, nil } func putInvoice(invoices, invoiceIndex, addIndex *bbolt.Bucket, i *Invoice, invoiceNum uint32, paymentHash lntypes.Hash) ( uint64, error) { // Create the invoice key which is just the big-endian representation // of the invoice number. var invoiceKey [4]byte byteOrder.PutUint32(invoiceKey[:], invoiceNum) // Increment the num invoice counter index so the next invoice bares // the proper ID. var scratch [4]byte invoiceCounter := invoiceNum + 1 byteOrder.PutUint32(scratch[:], invoiceCounter) if err := invoiceIndex.Put(numInvoicesKey, scratch[:]); err != nil { return 0, err } // Add the payment hash to the invoice index. This will let us quickly // identify if we can settle an incoming payment, and also to possibly // allow a single invoice to have multiple payment installations. err := invoiceIndex.Put(paymentHash[:], invoiceKey[:]) if err != nil { return 0, err } // Next, we'll obtain the next add invoice index (sequence // number), so we can properly place this invoice within this // event stream. nextAddSeqNo, err := addIndex.NextSequence() if err != nil { return 0, err } // With the next sequence obtained, we'll updating the event series in // the add index bucket to map this current add counter to the index of // this new invoice. var seqNoBytes [8]byte byteOrder.PutUint64(seqNoBytes[:], nextAddSeqNo) if err := addIndex.Put(seqNoBytes[:], invoiceKey[:]); err != nil { return 0, err } i.AddIndex = nextAddSeqNo // Finally, serialize the invoice itself to be written to the disk. var buf bytes.Buffer if err := serializeInvoice(&buf, i); err != nil { return 0, err } if err := invoices.Put(invoiceKey[:], buf.Bytes()); err != nil { return 0, err } return nextAddSeqNo, nil } // serializeInvoice serializes an invoice to a writer. // // Note: this function is in use for a migration. Before making changes that // would modify the on disk format, make a copy of the original code and store // it with the migration. func serializeInvoice(w io.Writer, i *Invoice) error { creationDateBytes, err := i.CreationDate.MarshalBinary() if err != nil { return err } settleDateBytes, err := i.SettleDate.MarshalBinary() if err != nil { return err } var fb bytes.Buffer err = i.Terms.Features.EncodeBase256(&fb) if err != nil { return err } featureBytes := fb.Bytes() preimage := [32]byte(i.Terms.PaymentPreimage) value := uint64(i.Terms.Value) cltvDelta := uint32(i.Terms.FinalCltvDelta) expiry := uint64(i.Terms.Expiry) amtPaid := uint64(i.AmtPaid) state := uint8(i.State) tlvStream, err := tlv.NewStream( // Memo and payreq. tlv.MakePrimitiveRecord(memoType, &i.Memo), tlv.MakePrimitiveRecord(payReqType, &i.PaymentRequest), // Add/settle metadata. tlv.MakePrimitiveRecord(createTimeType, &creationDateBytes), tlv.MakePrimitiveRecord(settleTimeType, &settleDateBytes), tlv.MakePrimitiveRecord(addIndexType, &i.AddIndex), tlv.MakePrimitiveRecord(settleIndexType, &i.SettleIndex), // Terms. tlv.MakePrimitiveRecord(preimageType, &preimage), tlv.MakePrimitiveRecord(valueType, &value), tlv.MakePrimitiveRecord(cltvDeltaType, &cltvDelta), tlv.MakePrimitiveRecord(expiryType, &expiry), tlv.MakePrimitiveRecord(paymentAddrType, &i.Terms.PaymentAddr), tlv.MakePrimitiveRecord(featuresType, &featureBytes), // Invoice state. tlv.MakePrimitiveRecord(invStateType, &state), tlv.MakePrimitiveRecord(amtPaidType, &amtPaid), ) if err != nil { return err } var b bytes.Buffer if err = tlvStream.Encode(&b); err != nil { return err } err = binary.Write(w, byteOrder, uint64(b.Len())) if err != nil { return err } if _, err = w.Write(b.Bytes()); err != nil { return err } return serializeHtlcs(w, i.Htlcs) } // serializeHtlcs serializes a map containing circuit keys and invoice htlcs to // a writer. func serializeHtlcs(w io.Writer, htlcs map[CircuitKey]*InvoiceHTLC) error { for key, htlc := range htlcs { // Encode the htlc in a tlv stream. chanID := key.ChanID.ToUint64() amt := uint64(htlc.Amt) mppTotalAmt := uint64(htlc.MppTotalAmt) acceptTime := uint64(htlc.AcceptTime.UnixNano()) resolveTime := uint64(htlc.ResolveTime.UnixNano()) state := uint8(htlc.State) var records []tlv.Record records = append(records, tlv.MakePrimitiveRecord(chanIDType, &chanID), tlv.MakePrimitiveRecord(htlcIDType, &key.HtlcID), tlv.MakePrimitiveRecord(amtType, &amt), tlv.MakePrimitiveRecord( acceptHeightType, &htlc.AcceptHeight, ), tlv.MakePrimitiveRecord(acceptTimeType, &acceptTime), tlv.MakePrimitiveRecord(resolveTimeType, &resolveTime), tlv.MakePrimitiveRecord(expiryHeightType, &htlc.Expiry), tlv.MakePrimitiveRecord(htlcStateType, &state), tlv.MakePrimitiveRecord(mppTotalAmtType, &mppTotalAmt), ) // Convert the custom records to tlv.Record types that are ready // for serialization. customRecords := tlv.MapToRecords(htlc.CustomRecords) // Append the custom records. Their ids are in the experimental // range and sorted, so there is no need to sort again. records = append(records, customRecords...) tlvStream, err := tlv.NewStream(records...) if err != nil { return err } var b bytes.Buffer if err := tlvStream.Encode(&b); err != nil { return err } // Write the length of the tlv stream followed by the stream // bytes. err = binary.Write(w, byteOrder, uint64(b.Len())) if err != nil { return err } if _, err := w.Write(b.Bytes()); err != nil { return err } } return nil } func fetchInvoice(invoiceNum []byte, invoices *bbolt.Bucket) (Invoice, error) { invoiceBytes := invoices.Get(invoiceNum) if invoiceBytes == nil { return Invoice{}, ErrInvoiceNotFound } invoiceReader := bytes.NewReader(invoiceBytes) return deserializeInvoice(invoiceReader) } func deserializeInvoice(r io.Reader) (Invoice, error) { var ( preimage [32]byte value uint64 cltvDelta uint32 expiry uint64 amtPaid uint64 state uint8 creationDateBytes []byte settleDateBytes []byte featureBytes []byte ) var i Invoice tlvStream, err := tlv.NewStream( // Memo and payreq. tlv.MakePrimitiveRecord(memoType, &i.Memo), tlv.MakePrimitiveRecord(payReqType, &i.PaymentRequest), // Add/settle metadata. tlv.MakePrimitiveRecord(createTimeType, &creationDateBytes), tlv.MakePrimitiveRecord(settleTimeType, &settleDateBytes), tlv.MakePrimitiveRecord(addIndexType, &i.AddIndex), tlv.MakePrimitiveRecord(settleIndexType, &i.SettleIndex), // Terms. tlv.MakePrimitiveRecord(preimageType, &preimage), tlv.MakePrimitiveRecord(valueType, &value), tlv.MakePrimitiveRecord(cltvDeltaType, &cltvDelta), tlv.MakePrimitiveRecord(expiryType, &expiry), tlv.MakePrimitiveRecord(paymentAddrType, &i.Terms.PaymentAddr), tlv.MakePrimitiveRecord(featuresType, &featureBytes), // Invoice state. tlv.MakePrimitiveRecord(invStateType, &state), tlv.MakePrimitiveRecord(amtPaidType, &amtPaid), ) if err != nil { return i, err } var bodyLen int64 err = binary.Read(r, byteOrder, &bodyLen) if err != nil { return i, err } lr := io.LimitReader(r, bodyLen) if err = tlvStream.Decode(lr); err != nil { return i, err } i.Terms.PaymentPreimage = lntypes.Preimage(preimage) i.Terms.Value = lnwire.MilliSatoshi(value) i.Terms.FinalCltvDelta = int32(cltvDelta) i.Terms.Expiry = time.Duration(expiry) i.AmtPaid = lnwire.MilliSatoshi(amtPaid) i.State = ContractState(state) err = i.CreationDate.UnmarshalBinary(creationDateBytes) if err != nil { return i, err } err = i.SettleDate.UnmarshalBinary(settleDateBytes) if err != nil { return i, err } rawFeatures := lnwire.NewRawFeatureVector() err = rawFeatures.DecodeBase256( bytes.NewReader(featureBytes), len(featureBytes), ) if err != nil { return i, err } i.Terms.Features = lnwire.NewFeatureVector( rawFeatures, lnwire.Features, ) i.Htlcs, err = deserializeHtlcs(r) return i, err } // deserializeHtlcs reads a list of invoice htlcs from a reader and returns it // as a map. func deserializeHtlcs(r io.Reader) (map[CircuitKey]*InvoiceHTLC, error) { htlcs := make(map[CircuitKey]*InvoiceHTLC, 0) for { // Read the length of the tlv stream for this htlc. var streamLen int64 if err := binary.Read(r, byteOrder, &streamLen); err != nil { if err == io.EOF { break } return nil, err } // Limit the reader so that it stops at the end of this htlc's // stream. htlcReader := io.LimitReader(r, streamLen) // Decode the contents into the htlc fields. var ( htlc InvoiceHTLC key CircuitKey chanID uint64 state uint8 acceptTime, resolveTime uint64 amt, mppTotalAmt uint64 ) tlvStream, err := tlv.NewStream( tlv.MakePrimitiveRecord(chanIDType, &chanID), tlv.MakePrimitiveRecord(htlcIDType, &key.HtlcID), tlv.MakePrimitiveRecord(amtType, &amt), tlv.MakePrimitiveRecord( acceptHeightType, &htlc.AcceptHeight, ), tlv.MakePrimitiveRecord(acceptTimeType, &acceptTime), tlv.MakePrimitiveRecord(resolveTimeType, &resolveTime), tlv.MakePrimitiveRecord(expiryHeightType, &htlc.Expiry), tlv.MakePrimitiveRecord(htlcStateType, &state), tlv.MakePrimitiveRecord(mppTotalAmtType, &mppTotalAmt), ) if err != nil { return nil, err } parsedTypes, err := tlvStream.DecodeWithParsedTypes(htlcReader) if err != nil { return nil, err } key.ChanID = lnwire.NewShortChanIDFromInt(chanID) htlc.AcceptTime = time.Unix(0, int64(acceptTime)) htlc.ResolveTime = time.Unix(0, int64(resolveTime)) htlc.State = HtlcState(state) htlc.Amt = lnwire.MilliSatoshi(amt) htlc.MppTotalAmt = lnwire.MilliSatoshi(mppTotalAmt) // Reconstruct the custom records fields from the parsed types // map return from the tlv parser. htlc.CustomRecords = hop.NewCustomRecords(parsedTypes) htlcs[key] = &htlc } return htlcs, nil } // copySlice allocates a new slice and copies the source into it. func copySlice(src []byte) []byte { dest := make([]byte, len(src)) copy(dest, src) return dest } // copyInvoice makes a deep copy of the supplied invoice. func copyInvoice(src *Invoice) *Invoice { dest := Invoice{ Memo: copySlice(src.Memo), PaymentRequest: copySlice(src.PaymentRequest), CreationDate: src.CreationDate, SettleDate: src.SettleDate, Terms: src.Terms, AddIndex: src.AddIndex, SettleIndex: src.SettleIndex, State: src.State, AmtPaid: src.AmtPaid, Htlcs: make( map[CircuitKey]*InvoiceHTLC, len(src.Htlcs), ), } dest.Terms.Features = src.Terms.Features.Clone() for k, v := range src.Htlcs { dest.Htlcs[k] = v } return &dest } // updateInvoice fetches the invoice, obtains the update descriptor from the // callback and applies the updates in a single db transaction. func (d *DB) updateInvoice(hash lntypes.Hash, invoices, settleIndex *bbolt.Bucket, invoiceNum []byte, callback InvoiceUpdateCallback) (*Invoice, error) { invoice, err := fetchInvoice(invoiceNum, invoices) if err != nil { return nil, err } // Create deep copy to prevent any accidental modification in the // callback. invoiceCopy := copyInvoice(&invoice) // Call the callback and obtain the update descriptor. update, err := callback(invoiceCopy) if err != nil { return &invoice, err } // If there is nothing to update, return early. if update == nil { return &invoice, nil } now := d.Now() // Update invoice state if the update descriptor indicates an invoice // state change. if update.State != nil { err := updateInvoiceState(&invoice, hash, *update.State) if err != nil { return nil, err } if update.State.NewState == ContractSettled { err := setSettleMetaFields( settleIndex, invoiceNum, &invoice, now, ) if err != nil { return nil, err } } } // Process add actions from update descriptor. for key, htlcUpdate := range update.AddHtlcs { if _, exists := invoice.Htlcs[key]; exists { return nil, fmt.Errorf("duplicate add of htlc %v", key) } // Force caller to supply htlc without custom records in a // consistent way. if htlcUpdate.CustomRecords == nil { return nil, errors.New("nil custom records map") } htlc := &InvoiceHTLC{ Amt: htlcUpdate.Amt, MppTotalAmt: htlcUpdate.MppTotalAmt, Expiry: htlcUpdate.Expiry, AcceptHeight: uint32(htlcUpdate.AcceptHeight), AcceptTime: now, State: HtlcStateAccepted, CustomRecords: htlcUpdate.CustomRecords, } invoice.Htlcs[key] = htlc } // Align htlc states with invoice state and recalculate amount paid. var ( amtPaid lnwire.MilliSatoshi cancelHtlcs = update.CancelHtlcs ) for key, htlc := range invoice.Htlcs { // Check whether this htlc needs to be canceled. If it does, // update the htlc state to Canceled. _, cancel := cancelHtlcs[key] if cancel { // Consistency check to verify that there is no overlap // between the add and cancel sets. if _, added := update.AddHtlcs[key]; added { return nil, fmt.Errorf("added htlc %v canceled", key) } err := cancelSingleHtlc(now, htlc, invoice.State) if err != nil { return nil, err } // Delete processed cancel action, so that we can check // later that there are no actions left. delete(cancelHtlcs, key) continue } // The invoice state may have changed and this could have // implications for the states of the individual htlcs. Align // the htlc state with the current invoice state. err := updateHtlc(now, htlc, invoice.State) if err != nil { return nil, err } // Update the running amount paid to this invoice. We don't // include accepted htlcs when the invoice is still open. if invoice.State != ContractOpen && (htlc.State == HtlcStateAccepted || htlc.State == HtlcStateSettled) { amtPaid += htlc.Amt } } invoice.AmtPaid = amtPaid // Verify that we didn't get an action for htlcs that are not present on // the invoice. if len(cancelHtlcs) > 0 { return nil, errors.New("cancel action on non-existent htlc(s)") } // Reserialize and update invoice. var buf bytes.Buffer if err := serializeInvoice(&buf, &invoice); err != nil { return nil, err } if err := invoices.Put(invoiceNum[:], buf.Bytes()); err != nil { return nil, err } return &invoice, nil } // updateInvoiceState validates and processes an invoice state update. func updateInvoiceState(invoice *Invoice, hash lntypes.Hash, update InvoiceStateUpdateDesc) error { // Returning to open is never allowed from any state. if update.NewState == ContractOpen { return ErrInvoiceCannotOpen } switch invoice.State { // Once a contract is accepted, we can only transition to settled or // canceled. Forbid transitioning back into this state. Otherwise this // state is identical to ContractOpen, so we fallthrough to apply the // same checks that we apply to open invoices. case ContractAccepted: if update.NewState == ContractAccepted { return ErrInvoiceCannotAccept } fallthrough // If a contract is open, permit a state transition to accepted, settled // or canceled. The only restriction is on transitioning to settled // where we ensure the preimage is valid. case ContractOpen: if update.NewState == ContractSettled { // Validate preimage. if update.Preimage.Hash() != hash { return ErrInvoicePreimageMismatch } invoice.Terms.PaymentPreimage = update.Preimage } // Once settled, we are in a terminal state. case ContractSettled: return ErrInvoiceAlreadySettled // Once canceled, we are in a terminal state. case ContractCanceled: return ErrInvoiceAlreadyCanceled default: return errors.New("unknown state transition") } invoice.State = update.NewState return nil } // cancelSingleHtlc validates cancelation of a single htlc and update its state. func cancelSingleHtlc(resolveTime time.Time, htlc *InvoiceHTLC, invState ContractState) error { // It is only possible to cancel individual htlcs on an open invoice. if invState != ContractOpen { return fmt.Errorf("htlc canceled on invoice in "+ "state %v", invState) } // It is only possible if the htlc is still pending. if htlc.State != HtlcStateAccepted { return fmt.Errorf("htlc canceled in state %v", htlc.State) } htlc.State = HtlcStateCanceled htlc.ResolveTime = resolveTime return nil } // updateHtlc aligns the state of an htlc with the given invoice state. func updateHtlc(resolveTime time.Time, htlc *InvoiceHTLC, invState ContractState) error { switch invState { case ContractSettled: if htlc.State == HtlcStateAccepted { htlc.State = HtlcStateSettled htlc.ResolveTime = resolveTime } case ContractCanceled: switch htlc.State { case HtlcStateAccepted: htlc.State = HtlcStateCanceled htlc.ResolveTime = resolveTime case HtlcStateSettled: return fmt.Errorf("cannot have a settled htlc with " + "invoice in state canceled") } case ContractOpen, ContractAccepted: if htlc.State == HtlcStateSettled { return fmt.Errorf("cannot have a settled htlc with "+ "invoice in state %v", invState) } default: return errors.New("unknown state transition") } return nil } // setSettleMetaFields updates the metadata associated with settlement of an // invoice. func setSettleMetaFields(settleIndex *bbolt.Bucket, invoiceNum []byte, invoice *Invoice, now time.Time) error { // Now that we know the invoice hasn't already been settled, we'll // update the settle index so we can place this settle event in the // proper location within our time series. nextSettleSeqNo, err := settleIndex.NextSequence() if err != nil { return err } var seqNoBytes [8]byte byteOrder.PutUint64(seqNoBytes[:], nextSettleSeqNo) if err := settleIndex.Put(seqNoBytes[:], invoiceNum); err != nil { return err } invoice.SettleDate = now invoice.SettleIndex = nextSettleSeqNo return nil }