lnd.xprv/channeldb/invoices.go

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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 (
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// 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
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// 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
// 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
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// 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
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// HtlcStateCanceled indicates the htlc is canceled back to the
// sender.
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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
// 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
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// 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
}
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
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// 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
// Expiry is the expiry height of this htlc.
Expiry uint32
// CustomRecords contains the custom key/value pairs that accompanied
// the htlc.
CustomRecords hop.CustomRecordSet
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
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}
// 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.
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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,
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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
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// 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,
2018-10-05 11:14:56 +03:00
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 {
2019-08-14 18:48:34 +03:00
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)
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),
)
// 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 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),
)
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)
// 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()
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
// 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
}
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
if update.State.NewState == ContractSettled {
err := setSettleMetaFields(
settleIndex, invoiceNum, &invoice, now,
)
if err != nil {
return nil, err
}
}
}
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
// 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)
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
}
// 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,
Expiry: htlcUpdate.Expiry,
AcceptHeight: uint32(htlcUpdate.AcceptHeight),
AcceptTime: now,
State: HtlcStateAccepted,
CustomRecords: htlcUpdate.CustomRecords,
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
}
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
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
}
// Delete processed cancel action, so that we can check
// later that there are no actions left.
delete(cancelHtlcs, key)
continue
invoices: replay awareness Previously the invoice registry wasn't aware of replayed htlcs. This was dealt with by keeping the invoice accept/settle logic idempotent, so that a replay wouldn't have an effect. This mechanism has two limitations: 1. No accurate tracking of the total amount paid to an invoice. The total amount couldn't just be increased with every htlc received, because it could be a replay which would lead to counting the htlc amount multiple times. Therefore the total amount was set to the amount of the first htlc that was received, even though there may have been multiple htlcs paying to the invoice. 2. Impossible to check htlc expiry consistently for hodl invoices. When an htlc is new, its expiry needs to be checked against the invoice cltv delta. But for a replay, that check must be skipped. The htlc was accepted in time, the invoice was moved to the accepted state and a replay some blocks later shouldn't lead to that htlc being cancelled. Because the invoice registry couldn't recognize replays, it stopped checking htlc expiry heights when the invoice reached the accepted state. This prevents hold htlcs from being cancelled after a restart. But unfortunately this also caused additional htlcs to be accepted on an already accepted invoice without their expiry being checked. In this commit, the invoice registry starts to persistently track htlcs so that replays can be recognized. For replays, an htlc resolution action is returned early. This fixes both limitations mentioned above.
2019-08-09 16:09:57 +03:00
}
// 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
}