lnd.xprv/invoices/update.go
carla 8cbed23f26
invoices: split resolution result into settle, fail and accept enums
This commit splits the resolution result enum into results divided
by outcome (settled, failed or accepted). This allows us to more
strictly control which resolution results can be used with which
HtlcResolution structs, to prevent the combination of a settle
resolution result with a failure resolution result, for example.
2020-02-06 19:41:39 +02:00

286 lines
8.7 KiB
Go

package invoices
import (
"errors"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/record"
)
// invoiceUpdateCtx is an object that describes the context for the invoice
// update to be carried out.
type invoiceUpdateCtx struct {
hash lntypes.Hash
circuitKey channeldb.CircuitKey
amtPaid lnwire.MilliSatoshi
expiry uint32
currentHeight int32
finalCltvRejectDelta int32
customRecords record.CustomSet
mpp *record.MPP
}
// log logs a message specific to this update context.
func (i *invoiceUpdateCtx) log(s string) {
log.Debugf("Invoice(%x): %v, amt=%v, expiry=%v, circuit=%v, mpp=%v",
i.hash[:], s, i.amtPaid, i.expiry, i.circuitKey, i.mpp)
}
// failRes is a helper function which creates a failure resolution with
// the information contained in the invoiceUpdateCtx and the fail resolution
// result provided.
func (i invoiceUpdateCtx) failRes(outcome FailResolutionResult) *HtlcFailResolution {
return NewFailResolution(i.circuitKey, i.currentHeight, outcome)
}
// settleRes is a helper function which creates a settle resolution with
// the information contained in the invoiceUpdateCtx and the preimage and
// the settle resolution result provided.
func (i invoiceUpdateCtx) settleRes(preimage lntypes.Preimage,
outcome SettleResolutionResult) *HtlcSettleResolution {
return NewSettleResolution(
preimage, i.circuitKey, i.currentHeight, outcome,
)
}
// acceptRes is a helper function which creates an accept resolution with
// the information contained in the invoiceUpdateCtx and the accept resolution
// result provided.
func (i invoiceUpdateCtx) acceptRes(outcome acceptResolutionResult) *htlcAcceptResolution {
return newAcceptResolution(i.circuitKey, outcome)
}
// updateInvoice is a callback for DB.UpdateInvoice that contains the invoice
// settlement logic. It returns a hltc resolution that indicates what the
// outcome of the update was.
func updateInvoice(ctx *invoiceUpdateCtx, inv *channeldb.Invoice) (
*channeldb.InvoiceUpdateDesc, HtlcResolution, error) {
// Don't update the invoice when this is a replayed htlc.
htlc, ok := inv.Htlcs[ctx.circuitKey]
if ok {
switch htlc.State {
case channeldb.HtlcStateCanceled:
return nil, ctx.failRes(ResultReplayToCanceled), nil
case channeldb.HtlcStateAccepted:
return nil, ctx.acceptRes(resultReplayToAccepted), nil
case channeldb.HtlcStateSettled:
return nil, ctx.settleRes(
inv.Terms.PaymentPreimage,
ResultReplayToSettled,
), nil
default:
return nil, nil, errors.New("unknown htlc state")
}
}
if ctx.mpp == nil {
return updateLegacy(ctx, inv)
}
return updateMpp(ctx, inv)
}
// updateMpp is a callback for DB.UpdateInvoice that contains the invoice
// settlement logic for mpp payments.
func updateMpp(ctx *invoiceUpdateCtx,
inv *channeldb.Invoice) (*channeldb.InvoiceUpdateDesc,
HtlcResolution, error) {
// Start building the accept descriptor.
acceptDesc := &channeldb.HtlcAcceptDesc{
Amt: ctx.amtPaid,
Expiry: ctx.expiry,
AcceptHeight: ctx.currentHeight,
MppTotalAmt: ctx.mpp.TotalMsat(),
CustomRecords: ctx.customRecords,
}
// Only accept payments to open invoices. This behaviour differs from
// non-mpp payments that are accepted even after the invoice is settled.
// Because non-mpp payments don't have a payment address, this is needed
// to thwart probing.
if inv.State != channeldb.ContractOpen {
return nil, ctx.failRes(ResultInvoiceNotOpen), nil
}
// Check the payment address that authorizes the payment.
if ctx.mpp.PaymentAddr() != inv.Terms.PaymentAddr {
return nil, ctx.failRes(ResultAddressMismatch), nil
}
// Don't accept zero-valued sets.
if ctx.mpp.TotalMsat() == 0 {
return nil, ctx.failRes(ResultHtlcSetTotalTooLow), nil
}
// Check that the total amt of the htlc set is high enough. In case this
// is a zero-valued invoice, it will always be enough.
if ctx.mpp.TotalMsat() < inv.Terms.Value {
return nil, ctx.failRes(ResultHtlcSetTotalTooLow), nil
}
// Check whether total amt matches other htlcs in the set.
var newSetTotal lnwire.MilliSatoshi
for _, htlc := range inv.Htlcs {
// Only consider accepted mpp htlcs. It is possible that there
// are htlcs registered in the invoice database that previously
// timed out and are in the canceled state now.
if htlc.State != channeldb.HtlcStateAccepted {
continue
}
if ctx.mpp.TotalMsat() != htlc.MppTotalAmt {
return nil, ctx.failRes(ResultHtlcSetTotalMismatch), nil
}
newSetTotal += htlc.Amt
}
// Add amount of new htlc.
newSetTotal += ctx.amtPaid
// Make sure the communicated set total isn't overpaid.
if newSetTotal > ctx.mpp.TotalMsat() {
return nil, ctx.failRes(ResultHtlcSetOverpayment), nil
}
// The invoice is still open. Check the expiry.
if ctx.expiry < uint32(ctx.currentHeight+ctx.finalCltvRejectDelta) {
return nil, ctx.failRes(ResultExpiryTooSoon), nil
}
if ctx.expiry < uint32(ctx.currentHeight+inv.Terms.FinalCltvDelta) {
return nil, ctx.failRes(ResultExpiryTooSoon), nil
}
// Record HTLC in the invoice database.
newHtlcs := map[channeldb.CircuitKey]*channeldb.HtlcAcceptDesc{
ctx.circuitKey: acceptDesc,
}
update := channeldb.InvoiceUpdateDesc{
AddHtlcs: newHtlcs,
}
// If the invoice cannot be settled yet, only record the htlc.
setComplete := newSetTotal == ctx.mpp.TotalMsat()
if !setComplete {
return &update, ctx.acceptRes(resultPartialAccepted), nil
}
// Check to see if we can settle or this is an hold invoice and
// we need to wait for the preimage.
holdInvoice := inv.Terms.PaymentPreimage == channeldb.UnknownPreimage
if holdInvoice {
update.State = &channeldb.InvoiceStateUpdateDesc{
NewState: channeldb.ContractAccepted,
}
return &update, ctx.acceptRes(resultAccepted), nil
}
update.State = &channeldb.InvoiceStateUpdateDesc{
NewState: channeldb.ContractSettled,
Preimage: inv.Terms.PaymentPreimage,
}
return &update, ctx.settleRes(
inv.Terms.PaymentPreimage, ResultSettled,
), nil
}
// updateLegacy is a callback for DB.UpdateInvoice that contains the invoice
// settlement logic for legacy payments.
func updateLegacy(ctx *invoiceUpdateCtx,
inv *channeldb.Invoice) (*channeldb.InvoiceUpdateDesc, HtlcResolution, error) {
// If the invoice is already canceled, there is no further
// checking to do.
if inv.State == channeldb.ContractCanceled {
return nil, ctx.failRes(ResultInvoiceAlreadyCanceled), nil
}
// If an invoice amount is specified, check that enough is paid. Also
// check this for duplicate payments if the invoice is already settled
// or accepted. In case this is a zero-valued invoice, it will always be
// enough.
if ctx.amtPaid < inv.Terms.Value {
return nil, ctx.failRes(ResultAmountTooLow), nil
}
// TODO(joostjager): Check invoice mpp required feature
// bit when feature becomes mandatory.
// Don't allow settling the invoice with an old style
// htlc if we are already in the process of gathering an
// mpp set.
for _, htlc := range inv.Htlcs {
if htlc.State == channeldb.HtlcStateAccepted &&
htlc.MppTotalAmt > 0 {
return nil, ctx.failRes(ResultMppInProgress), nil
}
}
// The invoice is still open. Check the expiry.
if ctx.expiry < uint32(ctx.currentHeight+ctx.finalCltvRejectDelta) {
return nil, ctx.failRes(ResultExpiryTooSoon), nil
}
if ctx.expiry < uint32(ctx.currentHeight+inv.Terms.FinalCltvDelta) {
return nil, ctx.failRes(ResultExpiryTooSoon), nil
}
// Record HTLC in the invoice database.
newHtlcs := map[channeldb.CircuitKey]*channeldb.HtlcAcceptDesc{
ctx.circuitKey: {
Amt: ctx.amtPaid,
Expiry: ctx.expiry,
AcceptHeight: ctx.currentHeight,
CustomRecords: ctx.customRecords,
},
}
update := channeldb.InvoiceUpdateDesc{
AddHtlcs: newHtlcs,
}
// Don't update invoice state if we are accepting a duplicate payment.
// We do accept or settle the HTLC.
switch inv.State {
case channeldb.ContractAccepted:
return &update, ctx.acceptRes(resultDuplicateToAccepted), nil
case channeldb.ContractSettled:
return &update, ctx.settleRes(
inv.Terms.PaymentPreimage, ResultDuplicateToSettled,
), nil
}
// Check to see if we can settle or this is an hold invoice and we need
// to wait for the preimage.
holdInvoice := inv.Terms.PaymentPreimage == channeldb.UnknownPreimage
if holdInvoice {
update.State = &channeldb.InvoiceStateUpdateDesc{
NewState: channeldb.ContractAccepted,
}
return &update, ctx.acceptRes(resultAccepted), nil
}
update.State = &channeldb.InvoiceStateUpdateDesc{
NewState: channeldb.ContractSettled,
Preimage: inv.Terms.PaymentPreimage,
}
return &update, ctx.settleRes(
inv.Terms.PaymentPreimage, ResultSettled,
), nil
}