lnd.xprv/contractcourt/htlc_timeout_resolver_test.go
carla fa46db9c48
multi: add resolver reports to Checkpoint
To allow us to write the outcome of our resolver to disk, we add
optional resolver reports to the CheckPoint function. Variadic params
are used because some checkpoints may have no reports (when the resolver
is not yet complete) and some may have two (in the case of a two stage
resolution).
2020-07-07 19:49:51 +02:00

399 lines
10 KiB
Go

package contractcourt
import (
"bytes"
"fmt"
"sync"
"testing"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/txscript"
"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/channeldb/kvdb"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwallet"
)
type dummySignature struct{}
func (s *dummySignature) Serialize() []byte {
return []byte{}
}
func (s *dummySignature) Verify(_ []byte, _ *btcec.PublicKey) bool {
return true
}
type mockSigner struct {
}
func (m *mockSigner) SignOutputRaw(tx *wire.MsgTx,
signDesc *input.SignDescriptor) (input.Signature, error) {
return &dummySignature{}, nil
}
func (m *mockSigner) ComputeInputScript(tx *wire.MsgTx,
signDesc *input.SignDescriptor) (*input.Script, error) {
return nil, nil
}
type mockWitnessBeacon struct {
preImageUpdates chan lntypes.Preimage
newPreimages chan []lntypes.Preimage
lookupPreimage map[lntypes.Hash]lntypes.Preimage
}
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) {
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 := &mockSigner{}
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)
}{
// 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
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
},
// 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(
&dummySignature{}, txscript.SigHashAll,
signer, fakeSignDesc, sweepTx,
)
if err != nil {
return nil, err
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
},
// 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(
&dummySignature{}, txscript.SigHashAll,
fakePreimageBytes, signer, fakeSignDesc,
sweepTx,
)
if err != nil {
return nil, err
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
},
// 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
}
templateTx.TxIn[0].Witness = witness
return templateTx, nil
},
},
}
notifier := &mockNotifier{
epochChan: make(chan *chainntnfs.BlockEpoch),
spendChan: make(chan *chainntnfs.SpendDetail),
confChan: make(chan *chainntnfs.TxConfirmation),
}
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)
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,
_ ...*channeldb.ResolverReport) error {
checkPointChan <- struct{}{}
return nil
},
}
resolver := &htlcTimeoutResolver{
contractResolverKit: *newContractResolverKit(
cfg,
),
}
resolver.htlcResolution.SweepSignDesc = *fakeSignDesc
// 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 {
resolver.htlcResolution.SignedTimeoutTx = sweepTx
}
// 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)
}
select {
case notifier.spendChan <- &chainntnfs.SpendDetail{
SpendingTx: spendingTx,
}:
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,
}:
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")
}
wg.Wait()
// Finally, the resolver should be marked as resolved.
if !resolver.resolved {
t.Fatalf("resolver should be marked as resolved")
}
}
}