lnd.xprv/contractcourt/htlc_timeout_resolver_test.go

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package contractcourt
import (
"bytes"
"fmt"
"reflect"
"sync"
"testing"
"time"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/txscript"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/input"
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"github.com/lightningnetwork/lnd/kvdb"
"github.com/lightningnetwork/lnd/lntest/mock"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/stretchr/testify/require"
)
type mockWitnessBeacon struct {
preImageUpdates chan lntypes.Preimage
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newPreimages chan []lntypes.Preimage
lookupPreimage map[lntypes.Hash]lntypes.Preimage
}
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func newMockWitnessBeacon() *mockWitnessBeacon {
return &mockWitnessBeacon{
preImageUpdates: make(chan lntypes.Preimage, 1),
newPreimages: make(chan []lntypes.Preimage),
lookupPreimage: make(map[lntypes.Hash]lntypes.Preimage),
}
}
func (m *mockWitnessBeacon) SubscribeUpdates() *WitnessSubscription {
return &WitnessSubscription{
WitnessUpdates: m.preImageUpdates,
CancelSubscription: func() {},
}
}
func (m *mockWitnessBeacon) LookupPreimage(payhash lntypes.Hash) (lntypes.Preimage, bool) {
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preimage, ok := m.lookupPreimage[payhash]
if !ok {
return lntypes.Preimage{}, false
}
return preimage, true
}
func (m *mockWitnessBeacon) AddPreimages(preimages ...lntypes.Preimage) error {
m.newPreimages <- preimages
return nil
}
// TestHtlcTimeoutResolver tests that the timeout resolver properly handles all
// variations of possible local+remote spends.
func TestHtlcTimeoutResolver(t *testing.T) {
t.Parallel()
fakePreimageBytes := bytes.Repeat([]byte{1}, lntypes.HashSize)
var (
htlcOutpoint wire.OutPoint
fakePreimage lntypes.Preimage
)
fakeSignDesc := &input.SignDescriptor{
Output: &wire.TxOut{},
}
copy(fakePreimage[:], fakePreimageBytes)
signer := &mock.DummySigner{}
sweepTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: htlcOutpoint,
Witness: [][]byte{{0x01}},
},
},
}
fakeTimeout := int32(5)
templateTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: htlcOutpoint,
},
},
}
testCases := []struct {
// name is a human readable description of the test case.
name string
// remoteCommit denotes if the commitment broadcast was the
// remote commitment or not.
remoteCommit bool
// timeout denotes if the HTLC should be let timeout, or if the
// "remote" party should sweep it on-chain. This also affects
// what type of resolution message we expect.
timeout bool
// txToBroadcast is a function closure that should generate the
// transaction that should spend the HTLC output. Test authors
// can use this to customize the witness used when spending to
// trigger various redemption cases.
txToBroadcast func() (*wire.MsgTx, error)
// outcome is the resolver outcome that we expect to be reported
// once the contract is fully resolved.
outcome channeldb.ResolverOutcome
}{
// Remote commitment is broadcast, we time out the HTLC on
// chain, and should expect a fail HTLC resolution.
{
name: "timeout remote tx",
remoteCommit: true,
timeout: true,
txToBroadcast: func() (*wire.MsgTx, error) {
witness, err := input.ReceiverHtlcSpendTimeout(
signer, fakeSignDesc, sweepTx,
fakeTimeout,
)
if err != nil {
return nil, err
}
// To avoid triggering the race detector by
// setting the witness the second time this
// method is called during tests, we return
// immediately if the witness is already set
// correctly.
if reflect.DeepEqual(
templateTx.TxIn[0].Witness, witness,
) {
return templateTx, nil
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
outcome: channeldb.ResolverOutcomeTimeout,
},
// Our local commitment is broadcast, we timeout the HTLC and
// still expect an HTLC fail resolution.
{
name: "timeout local tx",
remoteCommit: false,
timeout: true,
txToBroadcast: func() (*wire.MsgTx, error) {
witness, err := input.SenderHtlcSpendTimeout(
&mock.DummySignature{}, txscript.SigHashAll,
signer, fakeSignDesc, sweepTx,
)
if err != nil {
return nil, err
}
// To avoid triggering the race detector by
// setting the witness the second time this
// method is called during tests, we return
// immediately if the witness is already set
// correctly.
if reflect.DeepEqual(
templateTx.TxIn[0].Witness, witness,
) {
return templateTx, nil
}
templateTx.TxIn[0].Witness = witness
// Set the outpoint to be on our commitment, since
// we need to claim in two stages.
templateTx.TxIn[0].PreviousOutPoint = testChanPoint1
return templateTx, nil
},
outcome: channeldb.ResolverOutcomeTimeout,
},
// The remote commitment is broadcast, they sweep with the
// pre-image, we should get a settle HTLC resolution.
{
name: "success remote tx",
remoteCommit: true,
timeout: false,
txToBroadcast: func() (*wire.MsgTx, error) {
witness, err := input.ReceiverHtlcSpendRedeem(
&mock.DummySignature{}, txscript.SigHashAll,
fakePreimageBytes, signer, fakeSignDesc,
sweepTx,
)
if err != nil {
return nil, err
}
// To avoid triggering the race detector by
// setting the witness the second time this
// method is called during tests, we return
// immediately if the witness is already set
// correctly.
if reflect.DeepEqual(
templateTx.TxIn[0].Witness, witness,
) {
return templateTx, nil
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
outcome: channeldb.ResolverOutcomeClaimed,
},
// The local commitment is broadcast, they sweep it with a
// timeout from the output, and we should still get the HTLC
// settle resolution back.
{
name: "success local tx",
remoteCommit: false,
timeout: false,
txToBroadcast: func() (*wire.MsgTx, error) {
witness, err := input.SenderHtlcSpendRedeem(
signer, fakeSignDesc, sweepTx,
fakePreimageBytes,
)
if err != nil {
return nil, err
}
// To avoid triggering the race detector by
// setting the witness the second time this
// method is called during tests, we return
// immediately if the witness is already set
// correctly.
if reflect.DeepEqual(
templateTx.TxIn[0].Witness, witness,
) {
return templateTx, nil
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
outcome: channeldb.ResolverOutcomeClaimed,
},
}
notifier := &mock.ChainNotifier{
EpochChan: make(chan *chainntnfs.BlockEpoch),
SpendChan: make(chan *chainntnfs.SpendDetail),
ConfChan: make(chan *chainntnfs.TxConfirmation),
}
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witnessBeacon := newMockWitnessBeacon()
for _, testCase := range testCases {
t.Logf("Running test case: %v", testCase.name)
checkPointChan := make(chan struct{}, 1)
incubateChan := make(chan struct{}, 1)
resolutionChan := make(chan ResolutionMsg, 1)
reportChan := make(chan *channeldb.ResolverReport)
chainCfg := ChannelArbitratorConfig{
ChainArbitratorConfig: ChainArbitratorConfig{
Notifier: notifier,
PreimageDB: witnessBeacon,
IncubateOutputs: func(wire.OutPoint,
*lnwallet.OutgoingHtlcResolution,
*lnwallet.IncomingHtlcResolution,
uint32) error {
incubateChan <- struct{}{}
return nil
},
DeliverResolutionMsg: func(msgs ...ResolutionMsg) error {
if len(msgs) != 1 {
return fmt.Errorf("expected 1 "+
"resolution msg, instead got %v",
len(msgs))
}
resolutionChan <- msgs[0]
return nil
},
},
PutResolverReport: func(_ kvdb.RwTx,
_ *channeldb.ResolverReport) error {
return nil
},
}
cfg := ResolverConfig{
ChannelArbitratorConfig: chainCfg,
Checkpoint: func(_ ContractResolver,
reports ...*channeldb.ResolverReport) error {
checkPointChan <- struct{}{}
// Send all of our reports into the channel.
for _, report := range reports {
reportChan <- report
}
return nil
},
}
resolver := &htlcTimeoutResolver{
htlcResolution: lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: testChanPoint2,
SweepSignDesc: *fakeSignDesc,
},
contractResolverKit: *newContractResolverKit(
cfg,
),
htlc: channeldb.HTLC{
Amt: testHtlcAmt,
},
}
var reports []*channeldb.ResolverReport
// If the test case needs the remote commitment to be
// broadcast, then we'll set the timeout commit to a fake
// transaction to force the code path.
if !testCase.remoteCommit {
timeoutTx, err := testCase.txToBroadcast()
require.NoError(t, err)
resolver.htlcResolution.SignedTimeoutTx = timeoutTx
if testCase.timeout {
timeoutTxID := timeoutTx.TxHash()
reports = append(reports, &channeldb.ResolverReport{
OutPoint: timeoutTx.TxIn[0].PreviousOutPoint,
Amount: testHtlcAmt.ToSatoshis(),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeFirstStage,
SpendTxID: &timeoutTxID,
})
}
}
// With all the setup above complete, we can initiate the
// resolution process, and the bulk of our test.
var wg sync.WaitGroup
resolveErr := make(chan error, 1)
wg.Add(1)
go func() {
defer wg.Done()
_, err := resolver.Resolve()
if err != nil {
resolveErr <- err
}
}()
// At the output isn't yet in the nursery, we expect that we
// should receive an incubation request.
select {
case <-incubateChan:
case err := <-resolveErr:
t.Fatalf("unable to resolve HTLC: %v", err)
case <-time.After(time.Second * 5):
t.Fatalf("failed to receive incubation request")
}
// Next, the resolver should request a spend notification for
// the direct HTLC output. We'll use the txToBroadcast closure
// for the test case to generate the transaction that we'll
// send to the resolver.
spendingTx, err := testCase.txToBroadcast()
if err != nil {
t.Fatalf("unable to generate tx: %v", err)
}
spendTxHash := spendingTx.TxHash()
select {
case notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: spendingTx,
SpenderTxHash: &spendTxHash,
}:
case <-time.After(time.Second * 5):
t.Fatalf("failed to request spend ntfn")
}
if !testCase.timeout {
// If the resolver should settle now, then we'll
// extract the pre-image to be extracted and the
// resolution message sent.
select {
case newPreimage := <-witnessBeacon.newPreimages:
if newPreimage[0] != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, newPreimage)
}
case <-time.After(time.Second * 5):
t.Fatalf("pre-image not added")
}
// Finally, we should get a resolution message with the
// pre-image set within the message.
select {
case resolutionMsg := <-resolutionChan:
// Once again, the pre-images should match up.
if *resolutionMsg.PreImage != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, resolutionMsg.PreImage)
}
case <-time.After(time.Second * 5):
t.Fatalf("resolution not sent")
}
} else {
// Otherwise, the HTLC should now timeout. First, we
// should get a resolution message with a populated
// failure message.
select {
case resolutionMsg := <-resolutionChan:
if resolutionMsg.Failure == nil {
t.Fatalf("expected failure resolution msg")
}
case <-time.After(time.Second * 5):
t.Fatalf("resolution not sent")
}
// We should also get another request for the spend
// notification of the second-level transaction to
// indicate that it's been swept by the nursery, but
// only if this is a local commitment transaction.
if !testCase.remoteCommit {
select {
case notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: spendingTx,
SpenderTxHash: &spendTxHash,
}:
case <-time.After(time.Second * 5):
t.Fatalf("failed to request spend ntfn")
}
}
}
// In any case, before the resolver exits, it should checkpoint
// its final state.
select {
case <-checkPointChan:
case err := <-resolveErr:
t.Fatalf("unable to resolve HTLC: %v", err)
case <-time.After(time.Second * 5):
t.Fatalf("check point not received")
}
// Add a report to our set of expected reports with the outcome
// that the test specifies (either success or timeout).
spendTxID := spendingTx.TxHash()
amt := btcutil.Amount(fakeSignDesc.Output.Value)
reports = append(reports, &channeldb.ResolverReport{
OutPoint: testChanPoint2,
Amount: amt,
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: testCase.outcome,
SpendTxID: &spendTxID,
})
for _, report := range reports {
assertResolverReport(t, reportChan, report)
}
wg.Wait()
// Finally, the resolver should be marked as resolved.
if !resolver.resolved {
t.Fatalf("resolver should be marked as resolved")
}
}
}
// NOTE: the following tests essentially checks many of the same scenarios as
// the test above, but they expand on it by checking resuming from checkpoints
// at every stage.
// TestHtlcTimeoutSingleStage tests a remote commitment confirming, and the
// local node sweeping the HTLC output directly after timeout.
func TestHtlcTimeoutSingleStage(t *testing.T) {
commitOutpoint := wire.OutPoint{Index: 3}
sweepTx := &wire.MsgTx{
TxIn: []*wire.TxIn{{}},
TxOut: []*wire.TxOut{{}},
}
// singleStageResolution is a resolution for a htlc on the remote
// party's commitment.
singleStageResolution := lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: commitOutpoint,
SweepSignDesc: testSignDesc,
}
sweepTxid := sweepTx.TxHash()
claim := &channeldb.ResolverReport{
OutPoint: commitOutpoint,
Amount: btcutil.Amount(testSignDesc.Output.Value),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeTimeout,
SpendTxID: &sweepTxid,
}
checkpoints := []checkpoint{
{
// Output should be handed off to the nursery.
incubating: true,
},
{
// We send a confirmation the sweep tx from published
// by the nursery.
preCheckpoint: func(ctx *htlcResolverTestContext,
_ bool) error {
// The nursery will create and publish a sweep
// tx.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: sweepTx,
SpenderTxHash: &sweepTxid,
}
// The resolver should deliver a failure
// resolition message (indicating we
// successfully timed out the HTLC).
select {
case resolutionMsg := <-ctx.resolutionChan:
if resolutionMsg.Failure == nil {
t.Fatalf("expected failure resolution msg")
}
case <-time.After(time.Second * 5):
t.Fatalf("resolution not sent")
}
return nil
},
// After the sweep has confirmed, we expect the
// checkpoint to be resolved, and with the above
// report.
incubating: true,
resolved: true,
reports: []*channeldb.ResolverReport{
claim,
},
},
}
testHtlcTimeout(
t, singleStageResolution, checkpoints,
)
}
// TestHtlcTimeoutSecondStage tests a local commitment being confirmed, and the
// local node claiming the HTLC output using the second-level timeout tx.
func TestHtlcTimeoutSecondStage(t *testing.T) {
commitOutpoint := wire.OutPoint{Index: 2}
htlcOutpoint := wire.OutPoint{Index: 3}
sweepTx := &wire.MsgTx{
TxIn: []*wire.TxIn{{}},
TxOut: []*wire.TxOut{{}},
}
sweepHash := sweepTx.TxHash()
timeoutTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: commitOutpoint,
},
},
TxOut: []*wire.TxOut{
{
Value: 111,
PkScript: []byte{0xaa, 0xaa},
},
},
}
signer := &mock.DummySigner{}
witness, err := input.SenderHtlcSpendTimeout(
&mock.DummySignature{}, txscript.SigHashAll,
signer, &testSignDesc, timeoutTx,
)
require.NoError(t, err)
timeoutTx.TxIn[0].Witness = witness
timeoutTxid := timeoutTx.TxHash()
// twoStageResolution is a resolution for a htlc on the local
// party's commitment.
twoStageResolution := lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: htlcOutpoint,
SignedTimeoutTx: timeoutTx,
SweepSignDesc: testSignDesc,
}
firstStage := &channeldb.ResolverReport{
OutPoint: commitOutpoint,
Amount: testHtlcAmt.ToSatoshis(),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeFirstStage,
SpendTxID: &timeoutTxid,
}
secondState := &channeldb.ResolverReport{
OutPoint: htlcOutpoint,
Amount: btcutil.Amount(testSignDesc.Output.Value),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeTimeout,
SpendTxID: &sweepHash,
}
checkpoints := []checkpoint{
{
// Output should be handed off to the nursery.
incubating: true,
},
{
// We send a confirmation for our sweep tx to indicate
// that our sweep succeeded.
preCheckpoint: func(ctx *htlcResolverTestContext,
_ bool) error {
// The nursery will publish the timeout tx.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: timeoutTx,
SpenderTxHash: &timeoutTxid,
}
// The resolver should deliver a failure
// resolution message (indicating we
// successfully timed out the HTLC).
select {
case resolutionMsg := <-ctx.resolutionChan:
if resolutionMsg.Failure == nil {
t.Fatalf("expected failure resolution msg")
}
case <-time.After(time.Second * 1):
t.Fatalf("resolution not sent")
}
// Deliver spend of timeout tx.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: sweepTx,
SpenderTxHash: &sweepHash,
}
return nil
},
// After the sweep has confirmed, we expect the
// checkpoint to be resolved, and with the above
// reports.
incubating: true,
resolved: true,
reports: []*channeldb.ResolverReport{
firstStage, secondState,
},
},
}
testHtlcTimeout(
t, twoStageResolution, checkpoints,
)
}
// TestHtlcTimeoutSingleStageRemoteSpend tests that when a local commitment
// confirms, and the remote spends the HTLC output directly, we detect this and
// extract the preimage.
func TestHtlcTimeoutSingleStageRemoteSpend(t *testing.T) {
commitOutpoint := wire.OutPoint{Index: 2}
htlcOutpoint := wire.OutPoint{Index: 3}
spendTx := &wire.MsgTx{
TxIn: []*wire.TxIn{{}},
TxOut: []*wire.TxOut{{}},
}
fakePreimageBytes := bytes.Repeat([]byte{1}, lntypes.HashSize)
var fakePreimage lntypes.Preimage
copy(fakePreimage[:], fakePreimageBytes)
signer := &mock.DummySigner{}
witness, err := input.SenderHtlcSpendRedeem(
signer, &testSignDesc, spendTx,
fakePreimageBytes,
)
require.NoError(t, err)
spendTx.TxIn[0].Witness = witness
spendTxHash := spendTx.TxHash()
timeoutTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: commitOutpoint,
},
},
TxOut: []*wire.TxOut{
{
Value: 123,
PkScript: []byte{0xff, 0xff},
},
},
}
timeoutWitness, err := input.SenderHtlcSpendTimeout(
&mock.DummySignature{}, txscript.SigHashAll,
signer, &testSignDesc, timeoutTx,
)
require.NoError(t, err)
timeoutTx.TxIn[0].Witness = timeoutWitness
// twoStageResolution is a resolution for a htlc on the local
// party's commitment.
twoStageResolution := lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: htlcOutpoint,
SignedTimeoutTx: timeoutTx,
SweepSignDesc: testSignDesc,
}
claim := &channeldb.ResolverReport{
OutPoint: htlcOutpoint,
Amount: btcutil.Amount(testSignDesc.Output.Value),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeClaimed,
SpendTxID: &spendTxHash,
}
checkpoints := []checkpoint{
{
// Output should be handed off to the nursery.
incubating: true,
},
{
// We send a spend notification for a remote spend with
// the preimage.
preCheckpoint: func(ctx *htlcResolverTestContext,
_ bool) error {
witnessBeacon := ctx.resolver.(*htlcTimeoutResolver).PreimageDB.(*mockWitnessBeacon)
// The remote spends the output direcly with
// the preimage.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: spendTx,
SpenderTxHash: &spendTxHash,
}
// We should extract the preimage.
select {
case newPreimage := <-witnessBeacon.newPreimages:
if newPreimage[0] != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, newPreimage)
}
case <-time.After(time.Second * 5):
t.Fatalf("pre-image not added")
}
// Finally, we should get a resolution message
// with the pre-image set within the message.
select {
case resolutionMsg := <-ctx.resolutionChan:
if *resolutionMsg.PreImage != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, resolutionMsg.PreImage)
}
case <-time.After(time.Second * 5):
t.Fatalf("resolution not sent")
}
return nil
},
// After the success tx has confirmed, we expect the
// checkpoint to be resolved, and with the above
// report.
incubating: true,
resolved: true,
reports: []*channeldb.ResolverReport{
claim,
},
},
}
testHtlcTimeout(
t, twoStageResolution, checkpoints,
)
}
// TestHtlcTimeoutSecondStageRemoteSpend tests that when a remite commitment
// confirms, and the remote spends the output using the success tx, we
// properly detect this and extract the preimage.
func TestHtlcTimeoutSecondStageRemoteSpend(t *testing.T) {
commitOutpoint := wire.OutPoint{Index: 2}
remoteSuccessTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: commitOutpoint,
},
},
TxOut: []*wire.TxOut{},
}
fakePreimageBytes := bytes.Repeat([]byte{1}, lntypes.HashSize)
var fakePreimage lntypes.Preimage
copy(fakePreimage[:], fakePreimageBytes)
signer := &mock.DummySigner{}
witness, err := input.ReceiverHtlcSpendRedeem(
&mock.DummySignature{}, txscript.SigHashAll,
fakePreimageBytes, signer,
&testSignDesc, remoteSuccessTx,
)
require.NoError(t, err)
remoteSuccessTx.TxIn[0].Witness = witness
successTxid := remoteSuccessTx.TxHash()
// singleStageResolution allwoing the local node to sweep HTLC output
// directly from the remote commitment after timeout.
singleStageResolution := lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: commitOutpoint,
SweepSignDesc: testSignDesc,
}
claim := &channeldb.ResolverReport{
OutPoint: commitOutpoint,
Amount: btcutil.Amount(testSignDesc.Output.Value),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeClaimed,
SpendTxID: &successTxid,
}
checkpoints := []checkpoint{
{
// Output should be handed off to the nursery.
incubating: true,
},
{
// We send a confirmation for the remote's second layer
// success transcation.
preCheckpoint: func(ctx *htlcResolverTestContext,
_ bool) error {
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: remoteSuccessTx,
SpenderTxHash: &successTxid,
}
witnessBeacon := ctx.resolver.(*htlcTimeoutResolver).PreimageDB.(*mockWitnessBeacon)
// We expect the preimage to be extracted,
select {
case newPreimage := <-witnessBeacon.newPreimages:
if newPreimage[0] != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, newPreimage)
}
case <-time.After(time.Second * 5):
t.Fatalf("pre-image not added")
}
// Finally, we should get a resolution message with the
// pre-image set within the message.
select {
case resolutionMsg := <-ctx.resolutionChan:
if *resolutionMsg.PreImage != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, resolutionMsg.PreImage)
}
case <-time.After(time.Second * 5):
t.Fatalf("resolution not sent")
}
return nil
},
// After the sweep has confirmed, we expect the
// checkpoint to be resolved, and with the above
// report.
incubating: true,
resolved: true,
reports: []*channeldb.ResolverReport{
claim,
},
},
}
testHtlcTimeout(
t, singleStageResolution, checkpoints,
)
}
// TestHtlcTimeoutSecondStageSweeper tests that for anchor channels, when a
// local commitment confirms, the timeout tx is handed to the sweeper to claim
// the HTLC output.
func TestHtlcTimeoutSecondStageSweeper(t *testing.T) {
commitOutpoint := wire.OutPoint{Index: 2}
htlcOutpoint := wire.OutPoint{Index: 3}
sweepTx := &wire.MsgTx{
TxIn: []*wire.TxIn{{}},
TxOut: []*wire.TxOut{{}},
}
sweepHash := sweepTx.TxHash()
timeoutTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: commitOutpoint,
},
},
TxOut: []*wire.TxOut{
{
Value: 123,
PkScript: []byte{0xff, 0xff},
},
},
}
// We set the timeout witness since the script is used when subscribing
// to spends.
signer := &mock.DummySigner{}
timeoutWitness, err := input.SenderHtlcSpendTimeout(
&mock.DummySignature{}, txscript.SigHashAll,
signer, &testSignDesc, timeoutTx,
)
require.NoError(t, err)
timeoutTx.TxIn[0].Witness = timeoutWitness
reSignedTimeoutTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: wire.OutPoint{
Hash: chainhash.Hash{0xaa, 0xbb},
Index: 0,
},
},
timeoutTx.TxIn[0],
{
PreviousOutPoint: wire.OutPoint{
Hash: chainhash.Hash{0xaa, 0xbb},
Index: 2,
},
},
},
TxOut: []*wire.TxOut{
{
Value: 111,
PkScript: []byte{0xaa, 0xaa},
},
timeoutTx.TxOut[0],
},
}
reSignedHash := reSignedTimeoutTx.TxHash()
reSignedOutPoint := wire.OutPoint{
Hash: reSignedHash,
Index: 1,
}
// twoStageResolution is a resolution for a htlc on the local
// party's commitment, where the timout tx can be re-signed.
twoStageResolution := lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: htlcOutpoint,
SignedTimeoutTx: timeoutTx,
SignDetails: &input.SignDetails{
SignDesc: testSignDesc,
PeerSig: testSig,
},
SweepSignDesc: testSignDesc,
}
firstStage := &channeldb.ResolverReport{
OutPoint: commitOutpoint,
Amount: testHtlcAmt.ToSatoshis(),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeFirstStage,
SpendTxID: &reSignedHash,
}
secondState := &channeldb.ResolverReport{
OutPoint: reSignedOutPoint,
Amount: btcutil.Amount(testSignDesc.Output.Value),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeTimeout,
SpendTxID: &sweepHash,
}
checkpoints := []checkpoint{
{
// The output should be given to the sweeper.
preCheckpoint: func(ctx *htlcResolverTestContext,
_ bool) error {
resolver := ctx.resolver.(*htlcTimeoutResolver)
inp := <-resolver.Sweeper.(*mockSweeper).sweptInputs
op := inp.OutPoint()
if *op != commitOutpoint {
return fmt.Errorf("outpoint %v swept, "+
"expected %v", op,
commitOutpoint)
}
// Emulat the sweeper spending using the
// re-signed timeout tx.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: reSignedTimeoutTx,
SpenderInputIndex: 1,
SpenderTxHash: &reSignedHash,
SpendingHeight: 10,
}
return nil
},
// incubating=true is used to signal that the
// second-level transaction was confirmed.
incubating: true,
},
{
// We send a confirmation for our sweep tx to indicate
// that our sweep succeeded.
preCheckpoint: func(ctx *htlcResolverTestContext,
resumed bool) error {
// If we are resuming from a checkpoing, we
// expect the resolver to re-subscribe to a
// spend, hence we must resend it.
if resumed {
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: reSignedTimeoutTx,
SpenderInputIndex: 1,
SpenderTxHash: &reSignedHash,
SpendingHeight: 10,
}
}
// The resolver should deliver a failure
// resolution message (indicating we
// successfully timed out the HTLC).
select {
case resolutionMsg := <-ctx.resolutionChan:
if resolutionMsg.Failure == nil {
t.Fatalf("expected failure resolution msg")
}
case <-time.After(time.Second * 1):
t.Fatalf("resolution not sent")
}
// Mimic CSV lock expiring.
ctx.notifier.EpochChan <- &chainntnfs.BlockEpoch{
Height: 13,
}
// The timout tx output should now be given to
// the sweeper.
resolver := ctx.resolver.(*htlcTimeoutResolver)
inp := <-resolver.Sweeper.(*mockSweeper).sweptInputs
op := inp.OutPoint()
exp := wire.OutPoint{
Hash: reSignedHash,
Index: 1,
}
if *op != exp {
return fmt.Errorf("wrong outpoint swept")
}
// Notify about the spend, which should resolve
// the resolver.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: sweepTx,
SpenderTxHash: &sweepHash,
SpendingHeight: 14,
}
return nil
},
// After the sweep has confirmed, we expect the
// checkpoint to be resolved, and with the above
// reports.
incubating: true,
resolved: true,
reports: []*channeldb.ResolverReport{
firstStage,
secondState,
},
},
}
testHtlcTimeout(
t, twoStageResolution, checkpoints,
)
}
// TestHtlcTimeoutSecondStageSweeperRemoteSpend tests that if a local timeout
// tx is offered to the sweeper, but the output is swept by the remote node, we
// properly detect this and extract the preimage.
func TestHtlcTimeoutSecondStageSweeperRemoteSpend(t *testing.T) {
commitOutpoint := wire.OutPoint{Index: 2}
htlcOutpoint := wire.OutPoint{Index: 3}
timeoutTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: commitOutpoint,
},
},
TxOut: []*wire.TxOut{
{
Value: 123,
PkScript: []byte{0xff, 0xff},
},
},
}
// We set the timeout witness since the script is used when subscribing
// to spends.
signer := &mock.DummySigner{}
timeoutWitness, err := input.SenderHtlcSpendTimeout(
&mock.DummySignature{}, txscript.SigHashAll,
signer, &testSignDesc, timeoutTx,
)
require.NoError(t, err)
timeoutTx.TxIn[0].Witness = timeoutWitness
spendTx := &wire.MsgTx{
TxIn: []*wire.TxIn{{}},
TxOut: []*wire.TxOut{{}},
}
fakePreimageBytes := bytes.Repeat([]byte{1}, lntypes.HashSize)
var fakePreimage lntypes.Preimage
copy(fakePreimage[:], fakePreimageBytes)
witness, err := input.SenderHtlcSpendRedeem(
signer, &testSignDesc, spendTx,
fakePreimageBytes,
)
require.NoError(t, err)
spendTx.TxIn[0].Witness = witness
spendTxHash := spendTx.TxHash()
// twoStageResolution is a resolution for a htlc on the local
// party's commitment, where the timout tx can be re-signed.
twoStageResolution := lnwallet.OutgoingHtlcResolution{
ClaimOutpoint: htlcOutpoint,
SignedTimeoutTx: timeoutTx,
SignDetails: &input.SignDetails{
SignDesc: testSignDesc,
PeerSig: testSig,
},
SweepSignDesc: testSignDesc,
}
claim := &channeldb.ResolverReport{
OutPoint: htlcOutpoint,
Amount: btcutil.Amount(testSignDesc.Output.Value),
ResolverType: channeldb.ResolverTypeOutgoingHtlc,
ResolverOutcome: channeldb.ResolverOutcomeClaimed,
SpendTxID: &spendTxHash,
}
checkpoints := []checkpoint{
{
// The output should be given to the sweeper.
preCheckpoint: func(ctx *htlcResolverTestContext,
_ bool) error {
resolver := ctx.resolver.(*htlcTimeoutResolver)
inp := <-resolver.Sweeper.(*mockSweeper).sweptInputs
op := inp.OutPoint()
if *op != commitOutpoint {
return fmt.Errorf("outpoint %v swept, "+
"expected %v", op,
commitOutpoint)
}
// Emulate the remote sweeping the output with the preimage.
// re-signed timeout tx.
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: spendTx,
SpenderTxHash: &spendTxHash,
}
return nil
},
// incubating=true is used to signal that the
// second-level transaction was confirmed.
incubating: true,
},
{
// We send a confirmation for our sweep tx to indicate
// that our sweep succeeded.
preCheckpoint: func(ctx *htlcResolverTestContext,
resumed bool) error {
// If we are resuming from a checkpoing, we
// expect the resolver to re-subscribe to a
// spend, hence we must resend it.
if resumed {
fmt.Println("resumed")
ctx.notifier.SpendChan <- &chainntnfs.SpendDetail{
SpendingTx: spendTx,
SpenderTxHash: &spendTxHash,
}
}
witnessBeacon := ctx.resolver.(*htlcTimeoutResolver).PreimageDB.(*mockWitnessBeacon)
// We should extract the preimage.
select {
case newPreimage := <-witnessBeacon.newPreimages:
if newPreimage[0] != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, newPreimage)
}
case <-time.After(time.Second * 5):
t.Fatalf("pre-image not added")
}
// Finally, we should get a resolution message
// with the pre-image set within the message.
select {
case resolutionMsg := <-ctx.resolutionChan:
if *resolutionMsg.PreImage != fakePreimage {
t.Fatalf("wrong pre-image: "+
"expected %v, got %v",
fakePreimage, resolutionMsg.PreImage)
}
case <-time.After(time.Second * 5):
t.Fatalf("resolution not sent")
}
return nil
},
// After the sweep has confirmed, we expect the
// checkpoint to be resolved, and with the above
// reports.
incubating: true,
resolved: true,
reports: []*channeldb.ResolverReport{
claim,
},
},
}
testHtlcTimeout(
t, twoStageResolution, checkpoints,
)
}
func testHtlcTimeout(t *testing.T, resolution lnwallet.OutgoingHtlcResolution,
checkpoints []checkpoint) {
defer timeout(t)()
// We first run the resolver from start to finish, ensuring it gets
// checkpointed at every expected stage. We store the checkpointed data
// for the next portion of the test.
ctx := newHtlcResolverTestContext(t,
func(htlc channeldb.HTLC, cfg ResolverConfig) ContractResolver {
return &htlcTimeoutResolver{
contractResolverKit: *newContractResolverKit(cfg),
htlc: htlc,
htlcResolution: resolution,
}
},
)
checkpointedState := runFromCheckpoint(t, ctx, checkpoints)
// Now, from every checkpoint created, we re-create the resolver, and
// run the test from that checkpoint.
for i := range checkpointedState {
cp := bytes.NewReader(checkpointedState[i])
ctx := newHtlcResolverTestContext(t,
func(htlc channeldb.HTLC, cfg ResolverConfig) ContractResolver {
resolver, err := newTimeoutResolverFromReader(cp, cfg)
if err != nil {
t.Fatal(err)
}
resolver.Supplement(htlc)
resolver.htlcResolution = resolution
return resolver
},
)
// Run from the given checkpoint, ensuring we'll hit the rest.
_ = runFromCheckpoint(t, ctx, checkpoints[i+1:])
}
}