lnd.xprv/contractcourt/channel_arbitrator_test.go

2091 lines
59 KiB
Go

package contractcourt
import (
"errors"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"sync"
"testing"
"time"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/coreos/bbolt"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/clock"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/lnwire"
)
const (
defaultTimeout = time.Second * 5
// stateTimeout is the timeout we allow when waiting for state
// transitions.
stateTimeout = time.Second * 15
)
type mockArbitratorLog struct {
state ArbitratorState
newStates chan ArbitratorState
failLog bool
failFetch error
failCommit bool
failCommitState ArbitratorState
resolutions *ContractResolutions
resolvers map[ContractResolver]struct{}
commitSet *CommitSet
sync.Mutex
}
// A compile time check to ensure mockArbitratorLog meets the ArbitratorLog
// interface.
var _ ArbitratorLog = (*mockArbitratorLog)(nil)
func (b *mockArbitratorLog) CurrentState() (ArbitratorState, error) {
return b.state, nil
}
func (b *mockArbitratorLog) CommitState(s ArbitratorState) error {
if b.failCommit && s == b.failCommitState {
return fmt.Errorf("intentional commit error at state %v",
b.failCommitState)
}
b.state = s
b.newStates <- s
return nil
}
func (b *mockArbitratorLog) FetchUnresolvedContracts() ([]ContractResolver,
error) {
b.Lock()
v := make([]ContractResolver, len(b.resolvers))
idx := 0
for resolver := range b.resolvers {
v[idx] = resolver
idx++
}
b.Unlock()
return v, nil
}
func (b *mockArbitratorLog) InsertUnresolvedContracts(
resolvers ...ContractResolver) error {
b.Lock()
for _, resolver := range resolvers {
b.resolvers[resolver] = struct{}{}
}
b.Unlock()
return nil
}
func (b *mockArbitratorLog) SwapContract(oldContract,
newContract ContractResolver) error {
b.Lock()
delete(b.resolvers, oldContract)
b.resolvers[newContract] = struct{}{}
b.Unlock()
return nil
}
func (b *mockArbitratorLog) ResolveContract(res ContractResolver) error {
b.Lock()
delete(b.resolvers, res)
b.Unlock()
return nil
}
func (b *mockArbitratorLog) LogContractResolutions(c *ContractResolutions) error {
if b.failLog {
return fmt.Errorf("intentional log failure")
}
b.resolutions = c
return nil
}
func (b *mockArbitratorLog) FetchContractResolutions() (*ContractResolutions, error) {
if b.failFetch != nil {
return nil, b.failFetch
}
return b.resolutions, nil
}
func (b *mockArbitratorLog) FetchChainActions() (ChainActionMap, error) {
return nil, nil
}
func (b *mockArbitratorLog) InsertConfirmedCommitSet(c *CommitSet) error {
b.commitSet = c
return nil
}
func (b *mockArbitratorLog) FetchConfirmedCommitSet() (*CommitSet, error) {
return b.commitSet, nil
}
func (b *mockArbitratorLog) WipeHistory() error {
return nil
}
// testArbLog is a wrapper around an existing (ideally fully concrete
// ArbitratorLog) that lets us intercept certain calls like transitioning to a
// new state.
type testArbLog struct {
ArbitratorLog
newStates chan ArbitratorState
}
func (t *testArbLog) CommitState(s ArbitratorState) error {
if err := t.ArbitratorLog.CommitState(s); err != nil {
return err
}
t.newStates <- s
return nil
}
type mockChainIO struct{}
var _ lnwallet.BlockChainIO = (*mockChainIO)(nil)
func (*mockChainIO) GetBestBlock() (*chainhash.Hash, int32, error) {
return nil, 0, nil
}
func (*mockChainIO) GetUtxo(op *wire.OutPoint, _ []byte,
heightHint uint32, _ <-chan struct{}) (*wire.TxOut, error) {
return nil, nil
}
func (*mockChainIO) GetBlockHash(blockHeight int64) (*chainhash.Hash, error) {
return nil, nil
}
func (*mockChainIO) GetBlock(blockHash *chainhash.Hash) (*wire.MsgBlock, error) {
return nil, nil
}
type chanArbTestCtx struct {
t *testing.T
chanArb *ChannelArbitrator
cleanUp func()
resolvedChan chan struct{}
blockEpochs chan *chainntnfs.BlockEpoch
incubationRequests chan struct{}
resolutions chan []ResolutionMsg
log ArbitratorLog
}
func (c *chanArbTestCtx) CleanUp() {
if err := c.chanArb.Stop(); err != nil {
c.t.Fatalf("unable to stop chan arb: %v", err)
}
if c.cleanUp != nil {
c.cleanUp()
}
}
// AssertStateTransitions asserts that the state machine steps through the
// passed states in order.
func (c *chanArbTestCtx) AssertStateTransitions(expectedStates ...ArbitratorState) {
c.t.Helper()
var newStatesChan chan ArbitratorState
switch log := c.log.(type) {
case *mockArbitratorLog:
newStatesChan = log.newStates
case *testArbLog:
newStatesChan = log.newStates
default:
c.t.Fatalf("unable to assert state transitions with %T", log)
}
for _, exp := range expectedStates {
var state ArbitratorState
select {
case state = <-newStatesChan:
case <-time.After(defaultTimeout):
c.t.Fatalf("new state not received")
}
if state != exp {
c.t.Fatalf("expected new state %v, got %v", exp, state)
}
}
}
// AssertState checks that the ChannelArbitrator is in the state we expect it
// to be.
func (c *chanArbTestCtx) AssertState(expected ArbitratorState) {
if c.chanArb.state != expected {
c.t.Fatalf("expected state %v, was %v", expected, c.chanArb.state)
}
}
// Restart simulates a clean restart of the channel arbitrator, forcing it to
// walk through it's recovery logic. If this function returns nil, then a
// restart was successful. Note that the restart process keeps the log in
// place, in order to simulate proper persistence of the log. The caller can
// optionally provide a restart closure which will be executed before the
// resolver is started again, but after it is created.
func (c *chanArbTestCtx) Restart(restartClosure func(*chanArbTestCtx)) (*chanArbTestCtx, error) {
if err := c.chanArb.Stop(); err != nil {
return nil, err
}
newCtx, err := createTestChannelArbitrator(c.t, c.log)
if err != nil {
return nil, err
}
if restartClosure != nil {
restartClosure(newCtx)
}
if err := newCtx.chanArb.Start(); err != nil {
return nil, err
}
return newCtx, nil
}
// testChanArbOption applies custom settings to a channel arbitrator config for
// testing purposes.
type testChanArbOption func(cfg *ChannelArbitratorConfig)
// remoteInitiatorOption sets the MarkChannelClosed function in the
// Channel Arbitrator's config.
func withMarkClosed(markClosed func(*channeldb.ChannelCloseSummary,
...channeldb.ChannelStatus) error) testChanArbOption {
return func(cfg *ChannelArbitratorConfig) {
cfg.MarkChannelClosed = markClosed
}
}
// createTestChannelArbitrator returns a channel arbitrator test context which
// contains a channel arbitrator with default values. These values can be
// changed by providing options which overwrite the default config.
func createTestChannelArbitrator(t *testing.T, log ArbitratorLog,
opts ...testChanArbOption) (*chanArbTestCtx, error) {
blockEpochs := make(chan *chainntnfs.BlockEpoch)
blockEpoch := &chainntnfs.BlockEpochEvent{
Epochs: blockEpochs,
Cancel: func() {},
}
chanPoint := wire.OutPoint{}
shortChanID := lnwire.ShortChannelID{}
chanEvents := &ChainEventSubscription{
RemoteUnilateralClosure: make(chan *RemoteUnilateralCloseInfo, 1),
LocalUnilateralClosure: make(chan *LocalUnilateralCloseInfo, 1),
CooperativeClosure: make(chan *CooperativeCloseInfo, 1),
ContractBreach: make(chan *lnwallet.BreachRetribution, 1),
}
resolutionChan := make(chan []ResolutionMsg, 1)
incubateChan := make(chan struct{})
chainIO := &mockChainIO{}
chainArbCfg := ChainArbitratorConfig{
ChainIO: chainIO,
PublishTx: func(*wire.MsgTx) error {
return nil
},
DeliverResolutionMsg: func(msgs ...ResolutionMsg) error {
resolutionChan <- msgs
return nil
},
OutgoingBroadcastDelta: 5,
IncomingBroadcastDelta: 5,
Notifier: &mockNotifier{
epochChan: make(chan *chainntnfs.BlockEpoch),
spendChan: make(chan *chainntnfs.SpendDetail),
confChan: make(chan *chainntnfs.TxConfirmation),
},
IncubateOutputs: func(wire.OutPoint,
*lnwallet.OutgoingHtlcResolution,
*lnwallet.IncomingHtlcResolution, uint32) error {
incubateChan <- struct{}{}
return nil
},
OnionProcessor: &mockOnionProcessor{},
IsForwardedHTLC: func(chanID lnwire.ShortChannelID,
htlcIndex uint64) bool {
return true
},
Clock: clock.NewDefaultClock(),
}
// We'll use the resolvedChan to synchronize on call to
// MarkChannelResolved.
resolvedChan := make(chan struct{}, 1)
// Next we'll create the matching configuration struct that contains
// all interfaces and methods the arbitrator needs to do its job.
arbCfg := &ChannelArbitratorConfig{
ChanPoint: chanPoint,
ShortChanID: shortChanID,
BlockEpochs: blockEpoch,
MarkChannelResolved: func() error {
resolvedChan <- struct{}{}
return nil
},
ForceCloseChan: func() (*lnwallet.LocalForceCloseSummary, error) {
summary := &lnwallet.LocalForceCloseSummary{
CloseTx: &wire.MsgTx{},
HtlcResolutions: &lnwallet.HtlcResolutions{},
}
return summary, nil
},
MarkCommitmentBroadcasted: func(_ *wire.MsgTx, _ bool) error {
return nil
},
MarkChannelClosed: func(*channeldb.ChannelCloseSummary,
...channeldb.ChannelStatus) error {
return nil
},
IsPendingClose: false,
ChainArbitratorConfig: chainArbCfg,
ChainEvents: chanEvents,
}
// Apply all custom options to the config struct.
for _, option := range opts {
option(arbCfg)
}
var cleanUp func()
if log == nil {
dbDir, err := ioutil.TempDir("", "chanArb")
if err != nil {
return nil, err
}
dbPath := filepath.Join(dbDir, "testdb")
db, err := bbolt.Open(dbPath, 0600, nil)
if err != nil {
return nil, err
}
backingLog, err := newBoltArbitratorLog(
db, *arbCfg, chainhash.Hash{}, chanPoint,
)
if err != nil {
return nil, err
}
cleanUp = func() {
db.Close()
os.RemoveAll(dbDir)
}
log = &testArbLog{
ArbitratorLog: backingLog,
newStates: make(chan ArbitratorState),
}
}
htlcSets := make(map[HtlcSetKey]htlcSet)
chanArb := NewChannelArbitrator(*arbCfg, htlcSets, log)
return &chanArbTestCtx{
t: t,
chanArb: chanArb,
cleanUp: cleanUp,
resolvedChan: resolvedChan,
resolutions: resolutionChan,
blockEpochs: blockEpochs,
log: log,
incubationRequests: incubateChan,
}, nil
}
// TestChannelArbitratorCooperativeClose tests that the ChannelArbitertor
// correctly marks the channel resolved in case a cooperative close is
// confirmed.
func TestChannelArbitratorCooperativeClose(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
if err := chanArbCtx.chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer func() {
if err := chanArbCtx.chanArb.Stop(); err != nil {
t.Fatalf("unable to stop chan arb: %v", err)
}
}()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// We set up a channel to detect when MarkChannelClosed is called.
closeInfos := make(chan *channeldb.ChannelCloseSummary)
chanArbCtx.chanArb.cfg.MarkChannelClosed = func(
closeInfo *channeldb.ChannelCloseSummary,
statuses ...channeldb.ChannelStatus) error {
closeInfos <- closeInfo
return nil
}
// Cooperative close should do trigger a MarkChannelClosed +
// MarkChannelResolved.
closeInfo := &CooperativeCloseInfo{
&channeldb.ChannelCloseSummary{},
}
chanArbCtx.chanArb.cfg.ChainEvents.CooperativeClosure <- closeInfo
select {
case c := <-closeInfos:
if c.CloseType != channeldb.CooperativeClose {
t.Fatalf("expected cooperative close, got %v", c.CloseType)
}
case <-time.After(defaultTimeout):
t.Fatalf("timeout waiting for channel close")
}
// It should mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorRemoteForceClose checks that the ChannelArbitrator goes
// through the expected states if a remote force close is observed in the
// chain.
func TestChannelArbitratorRemoteForceClose(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// Send a remote force close event.
commitSpend := &chainntnfs.SpendDetail{
SpenderTxHash: &chainhash.Hash{},
}
uniClose := &lnwallet.UnilateralCloseSummary{
SpendDetail: commitSpend,
HtlcResolutions: &lnwallet.HtlcResolutions{},
}
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
CommitSet: CommitSet{
ConfCommitKey: &RemoteHtlcSet,
HtlcSets: make(map[HtlcSetKey][]channeldb.HTLC),
},
}
// It should transition StateDefault -> StateContractClosed ->
// StateFullyResolved.
chanArbCtx.AssertStateTransitions(
StateContractClosed, StateFullyResolved,
)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorLocalForceClose tests that the ChannelArbitrator goes
// through the expected states in case we request it to force close the channel,
// and the local force close event is observed in chain.
func TestChannelArbitratorLocalForceClose(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// We create a channel we can use to pause the ChannelArbitrator at the
// point where it broadcasts the close tx, and check its state.
stateChan := make(chan ArbitratorState)
chanArb.cfg.PublishTx = func(*wire.MsgTx) error {
// When the force close tx is being broadcasted, check that the
// state is correct at that point.
select {
case stateChan <- chanArb.state:
case <-chanArb.quit:
return fmt.Errorf("exiting")
}
return nil
}
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
// With the channel found, and the request crafted, we'll send over a
// force close request to the arbitrator that watches this channel.
chanArb.forceCloseReqs <- &forceCloseReq{
errResp: errChan,
closeTx: respChan,
}
// It should transition to StateBroadcastCommit.
chanArbCtx.AssertStateTransitions(StateBroadcastCommit)
// When it is broadcasting the force close, its state should be
// StateBroadcastCommit.
select {
case state := <-stateChan:
if state != StateBroadcastCommit {
t.Fatalf("state during PublishTx was %v", state)
}
case <-time.After(stateTimeout):
t.Fatalf("did not get state update")
}
// After broadcasting, transition should be to
// StateCommitmentBroadcasted.
chanArbCtx.AssertStateTransitions(StateCommitmentBroadcasted)
select {
case <-respChan:
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
select {
case err := <-errChan:
if err != nil {
t.Fatalf("error force closing channel: %v", err)
}
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
// After broadcasting the close tx, it should be in state
// StateCommitmentBroadcasted.
chanArbCtx.AssertState(StateCommitmentBroadcasted)
// Now notify about the local force close getting confirmed.
chanArb.cfg.ChainEvents.LocalUnilateralClosure <- &LocalUnilateralCloseInfo{
SpendDetail: &chainntnfs.SpendDetail{},
LocalForceCloseSummary: &lnwallet.LocalForceCloseSummary{
CloseTx: &wire.MsgTx{},
HtlcResolutions: &lnwallet.HtlcResolutions{},
},
ChannelCloseSummary: &channeldb.ChannelCloseSummary{},
}
// It should transition StateContractClosed -> StateFullyResolved.
chanArbCtx.AssertStateTransitions(StateContractClosed, StateFullyResolved)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorBreachClose tests that the ChannelArbitrator goes
// through the expected states in case we notice a breach in the chain, and
// gracefully exits.
func TestChannelArbitratorBreachClose(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer func() {
if err := chanArb.Stop(); err != nil {
t.Fatal(err)
}
}()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// Send a breach close event.
chanArb.cfg.ChainEvents.ContractBreach <- &lnwallet.BreachRetribution{}
// It should transition StateDefault -> StateFullyResolved.
chanArbCtx.AssertStateTransitions(
StateFullyResolved,
)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorLocalForceClosePendingHtlc tests that the
// ChannelArbitrator goes through the expected states in case we request it to
// force close a channel that still has an HTLC pending.
func TestChannelArbitratorLocalForceClosePendingHtlc(t *testing.T) {
// We create a new test context for this channel arb, notice that we
// pass in a nil ArbitratorLog which means that a default one backed by
// a real DB will be created. We need this for our test as we want to
// test proper restart recovery and resolver population.
chanArbCtx, err := createTestChannelArbitrator(t, nil)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
chanArb.cfg.PreimageDB = newMockWitnessBeacon()
chanArb.cfg.Registry = &mockRegistry{}
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// Create htlcUpdates channel.
htlcUpdates := make(chan *ContractUpdate)
signals := &ContractSignals{
HtlcUpdates: htlcUpdates,
ShortChanID: lnwire.ShortChannelID{},
}
chanArb.UpdateContractSignals(signals)
// Add HTLC to channel arbitrator.
htlcAmt := 10000
htlc := channeldb.HTLC{
Incoming: false,
Amt: lnwire.MilliSatoshi(htlcAmt),
HtlcIndex: 99,
}
outgoingDustHtlc := channeldb.HTLC{
Incoming: false,
Amt: 100,
HtlcIndex: 100,
OutputIndex: -1,
}
incomingDustHtlc := channeldb.HTLC{
Incoming: true,
Amt: 105,
HtlcIndex: 101,
OutputIndex: -1,
}
htlcSet := []channeldb.HTLC{
htlc, outgoingDustHtlc, incomingDustHtlc,
}
htlcUpdates <- &ContractUpdate{
HtlcKey: LocalHtlcSet,
Htlcs: htlcSet,
}
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
// With the channel found, and the request crafted, we'll send over a
// force close request to the arbitrator that watches this channel.
chanArb.forceCloseReqs <- &forceCloseReq{
errResp: errChan,
closeTx: respChan,
}
// The force close request should trigger broadcast of the commitment
// transaction.
chanArbCtx.AssertStateTransitions(
StateBroadcastCommit,
StateCommitmentBroadcasted,
)
select {
case <-respChan:
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
select {
case err := <-errChan:
if err != nil {
t.Fatalf("error force closing channel: %v", err)
}
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
// Now notify about the local force close getting confirmed.
closeTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: wire.OutPoint{},
Witness: [][]byte{
{0x1},
{0x2},
},
},
},
}
htlcOp := wire.OutPoint{
Hash: closeTx.TxHash(),
Index: 0,
}
// Set up the outgoing resolution. Populate SignedTimeoutTx because our
// commitment transaction got confirmed.
outgoingRes := lnwallet.OutgoingHtlcResolution{
Expiry: 10,
SweepSignDesc: input.SignDescriptor{
Output: &wire.TxOut{},
},
SignedTimeoutTx: &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: htlcOp,
Witness: [][]byte{{}},
},
},
TxOut: []*wire.TxOut{
{},
},
},
}
chanArb.cfg.ChainEvents.LocalUnilateralClosure <- &LocalUnilateralCloseInfo{
SpendDetail: &chainntnfs.SpendDetail{},
LocalForceCloseSummary: &lnwallet.LocalForceCloseSummary{
CloseTx: closeTx,
HtlcResolutions: &lnwallet.HtlcResolutions{
OutgoingHTLCs: []lnwallet.OutgoingHtlcResolution{
outgoingRes,
},
},
},
ChannelCloseSummary: &channeldb.ChannelCloseSummary{},
CommitSet: CommitSet{
ConfCommitKey: &LocalHtlcSet,
HtlcSets: map[HtlcSetKey][]channeldb.HTLC{
LocalHtlcSet: htlcSet,
},
},
}
chanArbCtx.AssertStateTransitions(
StateContractClosed,
StateWaitingFullResolution,
)
// We expect an immediate resolution message for the outgoing dust htlc.
// It is not resolvable on-chain.
select {
case msgs := <-chanArbCtx.resolutions:
if len(msgs) != 1 {
t.Fatalf("expected 1 message, instead got %v", len(msgs))
}
if msgs[0].HtlcIndex != outgoingDustHtlc.HtlcIndex {
t.Fatalf("wrong htlc index: expected %v, got %v",
outgoingDustHtlc.HtlcIndex, msgs[0].HtlcIndex)
}
case <-time.After(defaultTimeout):
t.Fatalf("resolution msgs not sent")
}
// We'll grab the old notifier here as our resolvers are still holding
// a reference to this instance, and a new one will be created when we
// restart the channel arb below.
oldNotifier := chanArb.cfg.Notifier.(*mockNotifier)
// At this point, in order to simulate a restart, we'll re-create the
// channel arbitrator. We do this to ensure that all information
// required to properly resolve this HTLC are populated.
if err := chanArb.Stop(); err != nil {
t.Fatalf("unable to stop chan arb: %v", err)
}
// We'll no re-create the resolver, notice that we use the existing
// arbLog so it carries over the same on-disk state.
chanArbCtxNew, err := chanArbCtx.Restart(nil)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb = chanArbCtxNew.chanArb
defer chanArbCtxNew.CleanUp()
// Post restart, it should be the case that our resolver was properly
// supplemented, and we only have a single resolver in the final set.
if len(chanArb.activeResolvers) != 1 {
t.Fatalf("expected single resolver, instead got: %v",
len(chanArb.activeResolvers))
}
// We'll now examine the in-memory state of the active resolvers to
// ensure t hey were populated properly.
resolver := chanArb.activeResolvers[0]
outgoingResolver, ok := resolver.(*htlcOutgoingContestResolver)
if !ok {
t.Fatalf("expected outgoing contest resolver, got %vT",
resolver)
}
// The resolver should have its htlc amt field populated as it.
if int64(outgoingResolver.htlc.Amt) != int64(htlcAmt) {
t.Fatalf("wrong htlc amount: expected %v, got %v,",
htlcAmt, int64(outgoingResolver.htlc.Amt))
}
// htlcOutgoingContestResolver is now active and waiting for the HTLC to
// expire. It should not yet have passed it on for incubation.
select {
case <-chanArbCtx.incubationRequests:
t.Fatalf("contract should not be incubated yet")
default:
}
// Send a notification that the expiry height has been reached.
oldNotifier.epochChan <- &chainntnfs.BlockEpoch{Height: 10}
// htlcOutgoingContestResolver is now transforming into a
// htlcTimeoutResolver and should send the contract off for incubation.
select {
case <-chanArbCtx.incubationRequests:
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
// Notify resolver that the HTLC output of the commitment has been
// spent.
oldNotifier.spendChan <- &chainntnfs.SpendDetail{SpendingTx: closeTx}
// Finally, we should also receive a resolution message instructing the
// switch to cancel back the HTLC.
select {
case msgs := <-chanArbCtx.resolutions:
if len(msgs) != 1 {
t.Fatalf("expected 1 message, instead got %v", len(msgs))
}
if msgs[0].HtlcIndex != htlc.HtlcIndex {
t.Fatalf("wrong htlc index: expected %v, got %v",
htlc.HtlcIndex, msgs[0].HtlcIndex)
}
case <-time.After(defaultTimeout):
t.Fatalf("resolution msgs not sent")
}
// As this is our own commitment transaction, the HTLC will go through
// to the second level. Channel arbitrator should still not be marked
// as resolved.
select {
case <-chanArbCtxNew.resolvedChan:
t.Fatalf("channel resolved prematurely")
default:
}
// Notify resolver that the second level transaction is spent.
oldNotifier.spendChan <- &chainntnfs.SpendDetail{SpendingTx: closeTx}
// At this point channel should be marked as resolved.
chanArbCtxNew.AssertStateTransitions(StateFullyResolved)
select {
case <-chanArbCtxNew.resolvedChan:
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorLocalForceCloseRemoteConfiremd tests that the
// ChannelArbitrator behaves as expected in the case where we request a local
// force close, but a remote commitment ends up being confirmed in chain.
func TestChannelArbitratorLocalForceCloseRemoteConfirmed(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// Create a channel we can use to assert the state when it publishes
// the close tx.
stateChan := make(chan ArbitratorState)
chanArb.cfg.PublishTx = func(*wire.MsgTx) error {
// When the force close tx is being broadcasted, check that the
// state is correct at that point.
select {
case stateChan <- chanArb.state:
case <-chanArb.quit:
return fmt.Errorf("exiting")
}
return nil
}
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
// With the channel found, and the request crafted, we'll send over a
// force close request to the arbitrator that watches this channel.
chanArb.forceCloseReqs <- &forceCloseReq{
errResp: errChan,
closeTx: respChan,
}
// It should transition to StateBroadcastCommit.
chanArbCtx.AssertStateTransitions(StateBroadcastCommit)
// We expect it to be in state StateBroadcastCommit when publishing
// the force close.
select {
case state := <-stateChan:
if state != StateBroadcastCommit {
t.Fatalf("state during PublishTx was %v", state)
}
case <-time.After(stateTimeout):
t.Fatalf("no state update received")
}
// After broadcasting, transition should be to
// StateCommitmentBroadcasted.
chanArbCtx.AssertStateTransitions(StateCommitmentBroadcasted)
// Wait for a response to the force close.
select {
case <-respChan:
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
select {
case err := <-errChan:
if err != nil {
t.Fatalf("error force closing channel: %v", err)
}
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
// The state should be StateCommitmentBroadcasted.
chanArbCtx.AssertState(StateCommitmentBroadcasted)
// Now notify about the _REMOTE_ commitment getting confirmed.
commitSpend := &chainntnfs.SpendDetail{
SpenderTxHash: &chainhash.Hash{},
}
uniClose := &lnwallet.UnilateralCloseSummary{
SpendDetail: commitSpend,
HtlcResolutions: &lnwallet.HtlcResolutions{},
}
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
}
// It should transition StateContractClosed -> StateFullyResolved.
chanArbCtx.AssertStateTransitions(StateContractClosed, StateFullyResolved)
// It should resolve.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(stateTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorLocalForceCloseDoubleSpend tests that the
// ChannelArbitrator behaves as expected in the case where we request a local
// force close, but we fail broadcasting our commitment because a remote
// commitment has already been published.
func TestChannelArbitratorLocalForceDoubleSpend(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// Return ErrDoubleSpend when attempting to publish the tx.
stateChan := make(chan ArbitratorState)
chanArb.cfg.PublishTx = func(*wire.MsgTx) error {
// When the force close tx is being broadcasted, check that the
// state is correct at that point.
select {
case stateChan <- chanArb.state:
case <-chanArb.quit:
return fmt.Errorf("exiting")
}
return lnwallet.ErrDoubleSpend
}
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
// With the channel found, and the request crafted, we'll send over a
// force close request to the arbitrator that watches this channel.
chanArb.forceCloseReqs <- &forceCloseReq{
errResp: errChan,
closeTx: respChan,
}
// It should transition to StateBroadcastCommit.
chanArbCtx.AssertStateTransitions(StateBroadcastCommit)
// We expect it to be in state StateBroadcastCommit when publishing
// the force close.
select {
case state := <-stateChan:
if state != StateBroadcastCommit {
t.Fatalf("state during PublishTx was %v", state)
}
case <-time.After(stateTimeout):
t.Fatalf("no state update received")
}
// After broadcasting, transition should be to
// StateCommitmentBroadcasted.
chanArbCtx.AssertStateTransitions(StateCommitmentBroadcasted)
// Wait for a response to the force close.
select {
case <-respChan:
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
select {
case err := <-errChan:
if err != nil {
t.Fatalf("error force closing channel: %v", err)
}
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
// The state should be StateCommitmentBroadcasted.
chanArbCtx.AssertState(StateCommitmentBroadcasted)
// Now notify about the _REMOTE_ commitment getting confirmed.
commitSpend := &chainntnfs.SpendDetail{
SpenderTxHash: &chainhash.Hash{},
}
uniClose := &lnwallet.UnilateralCloseSummary{
SpendDetail: commitSpend,
HtlcResolutions: &lnwallet.HtlcResolutions{},
}
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
}
// It should transition StateContractClosed -> StateFullyResolved.
chanArbCtx.AssertStateTransitions(StateContractClosed, StateFullyResolved)
// It should resolve.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(stateTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorPersistence tests that the ChannelArbitrator is able to
// keep advancing the state machine from various states after restart.
func TestChannelArbitratorPersistence(t *testing.T) {
// Start out with a log that will fail writing the set of resolutions.
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
failLog: true,
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
// It should start in StateDefault.
chanArbCtx.AssertState(StateDefault)
// Send a remote force close event.
commitSpend := &chainntnfs.SpendDetail{
SpenderTxHash: &chainhash.Hash{},
}
uniClose := &lnwallet.UnilateralCloseSummary{
SpendDetail: commitSpend,
HtlcResolutions: &lnwallet.HtlcResolutions{},
}
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
}
// Since writing the resolutions fail, the arbitrator should not
// advance to the next state.
time.Sleep(100 * time.Millisecond)
if log.state != StateDefault {
t.Fatalf("expected to stay in StateDefault")
}
// Restart the channel arb, this'll use the same long and prior
// context.
chanArbCtx, err = chanArbCtx.Restart(nil)
if err != nil {
t.Fatalf("unable to restart channel arb: %v", err)
}
chanArb = chanArbCtx.chanArb
// Again, it should start up in the default state.
chanArbCtx.AssertState(StateDefault)
// Now we make the log succeed writing the resolutions, but fail when
// attempting to close the channel.
log.failLog = false
chanArb.cfg.MarkChannelClosed = func(*channeldb.ChannelCloseSummary,
...channeldb.ChannelStatus) error {
return fmt.Errorf("intentional close error")
}
// Send a new remote force close event.
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
}
// Since closing the channel failed, the arbitrator should stay in the
// default state.
time.Sleep(100 * time.Millisecond)
if log.state != StateDefault {
t.Fatalf("expected to stay in StateDefault")
}
// Restart once again to simulate yet another restart.
chanArbCtx, err = chanArbCtx.Restart(nil)
if err != nil {
t.Fatalf("unable to restart channel arb: %v", err)
}
chanArb = chanArbCtx.chanArb
// Starts out in StateDefault.
chanArbCtx.AssertState(StateDefault)
// Now make fetching the resolutions fail.
log.failFetch = fmt.Errorf("intentional fetch failure")
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
}
// Since logging the resolutions and closing the channel now succeeds,
// it should advance to StateContractClosed.
chanArbCtx.AssertStateTransitions(StateContractClosed)
// It should not advance further, however, as fetching resolutions
// failed.
time.Sleep(100 * time.Millisecond)
if log.state != StateContractClosed {
t.Fatalf("expected to stay in StateContractClosed")
}
chanArb.Stop()
// Create a new arbitrator, and now make fetching resolutions succeed.
log.failFetch = nil
chanArbCtx, err = chanArbCtx.Restart(nil)
if err != nil {
t.Fatalf("unable to restart channel arb: %v", err)
}
defer chanArbCtx.CleanUp()
// Finally it should advance to StateFullyResolved.
chanArbCtx.AssertStateTransitions(StateFullyResolved)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorForceCloseBreachedChannel tests that the channel
// arbitrator is able to handle a channel in the process of being force closed
// is breached by the remote node. In these cases we expect the
// ChannelArbitrator to gracefully exit, as the breach is handled by other
// subsystems.
func TestChannelArbitratorForceCloseBreachedChannel(t *testing.T) {
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
// It should start in StateDefault.
chanArbCtx.AssertState(StateDefault)
// We start by attempting a local force close. We'll return an
// unexpected publication error, causing the state machine to halt.
expErr := errors.New("intentional publication error")
stateChan := make(chan ArbitratorState)
chanArb.cfg.PublishTx = func(*wire.MsgTx) error {
// When the force close tx is being broadcasted, check that the
// state is correct at that point.
select {
case stateChan <- chanArb.state:
case <-chanArb.quit:
return fmt.Errorf("exiting")
}
return expErr
}
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
// With the channel found, and the request crafted, we'll send over a
// force close request to the arbitrator that watches this channel.
chanArb.forceCloseReqs <- &forceCloseReq{
errResp: errChan,
closeTx: respChan,
}
// It should transition to StateBroadcastCommit.
chanArbCtx.AssertStateTransitions(StateBroadcastCommit)
// We expect it to be in state StateBroadcastCommit when attempting
// the force close.
select {
case state := <-stateChan:
if state != StateBroadcastCommit {
t.Fatalf("state during PublishTx was %v", state)
}
case <-time.After(stateTimeout):
t.Fatalf("no state update received")
}
// Make sure we get the expected error.
select {
case err := <-errChan:
if err != expErr {
t.Fatalf("unexpected error force closing channel: %v",
err)
}
case <-time.After(defaultTimeout):
t.Fatalf("no response received")
}
// We mimic that the channel is breached while the channel arbitrator
// is down. This means that on restart it will be started with a
// pending close channel, of type BreachClose.
chanArbCtx, err = chanArbCtx.Restart(func(c *chanArbTestCtx) {
c.chanArb.cfg.IsPendingClose = true
c.chanArb.cfg.ClosingHeight = 100
c.chanArb.cfg.CloseType = channeldb.BreachClose
})
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
defer chanArbCtx.CleanUp()
// Finally it should advance to StateFullyResolved.
chanArbCtx.AssertStateTransitions(StateFullyResolved)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
// TestChannelArbitratorCommitFailure tests that the channel arbitrator is able
// to recover from a failed CommitState call at restart.
func TestChannelArbitratorCommitFailure(t *testing.T) {
testCases := []struct {
// closeType is the type of channel close we want ot test.
closeType channeldb.ClosureType
// sendEvent is a function that will send the event
// corresponding to this test's closeType to the passed
// ChannelArbitrator.
sendEvent func(chanArb *ChannelArbitrator)
// expectedStates is the states we expect the state machine to
// go through after a restart and successful log commit.
expectedStates []ArbitratorState
}{
{
closeType: channeldb.CooperativeClose,
sendEvent: func(chanArb *ChannelArbitrator) {
closeInfo := &CooperativeCloseInfo{
&channeldb.ChannelCloseSummary{},
}
chanArb.cfg.ChainEvents.CooperativeClosure <- closeInfo
},
expectedStates: []ArbitratorState{StateFullyResolved},
},
{
closeType: channeldb.RemoteForceClose,
sendEvent: func(chanArb *ChannelArbitrator) {
commitSpend := &chainntnfs.SpendDetail{
SpenderTxHash: &chainhash.Hash{},
}
uniClose := &lnwallet.UnilateralCloseSummary{
SpendDetail: commitSpend,
HtlcResolutions: &lnwallet.HtlcResolutions{},
}
chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: uniClose,
}
},
expectedStates: []ArbitratorState{StateContractClosed, StateFullyResolved},
},
{
closeType: channeldb.LocalForceClose,
sendEvent: func(chanArb *ChannelArbitrator) {
chanArb.cfg.ChainEvents.LocalUnilateralClosure <- &LocalUnilateralCloseInfo{
SpendDetail: &chainntnfs.SpendDetail{},
LocalForceCloseSummary: &lnwallet.LocalForceCloseSummary{
CloseTx: &wire.MsgTx{},
HtlcResolutions: &lnwallet.HtlcResolutions{},
},
ChannelCloseSummary: &channeldb.ChannelCloseSummary{},
}
},
expectedStates: []ArbitratorState{StateContractClosed, StateFullyResolved},
},
}
for _, test := range testCases {
test := test
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
failCommit: true,
// Set the log to fail on the first expected state
// after state machine progress for this test case.
failCommitState: test.expectedStates[0],
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
// It should start in StateDefault.
chanArbCtx.AssertState(StateDefault)
closed := make(chan struct{})
chanArb.cfg.MarkChannelClosed = func(
*channeldb.ChannelCloseSummary,
...channeldb.ChannelStatus) error {
close(closed)
return nil
}
// Send the test event to trigger the state machine.
test.sendEvent(chanArb)
select {
case <-closed:
case <-time.After(defaultTimeout):
t.Fatalf("channel was not marked closed")
}
// Since the channel was marked closed in the database, but the
// commit to the next state failed, the state should still be
// StateDefault.
time.Sleep(100 * time.Millisecond)
if log.state != StateDefault {
t.Fatalf("expected to stay in StateDefault, instead "+
"has %v", log.state)
}
chanArb.Stop()
// Start the arbitrator again, with IsPendingClose reporting
// the channel closed in the database.
log.failCommit = false
chanArbCtx, err = chanArbCtx.Restart(func(c *chanArbTestCtx) {
c.chanArb.cfg.IsPendingClose = true
c.chanArb.cfg.ClosingHeight = 100
c.chanArb.cfg.CloseType = test.closeType
})
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
// Since the channel is marked closed in the database, it
// should advance to the expected states.
chanArbCtx.AssertStateTransitions(test.expectedStates...)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
}
}
// TestChannelArbitratorEmptyResolutions makes sure that a channel that is
// pending close in the database, but haven't had any resolutions logged will
// not be marked resolved. This situation must be handled to avoid closing
// channels from earlier versions of the ChannelArbitrator, which didn't have a
// proper handoff from the ChainWatcher, and we could risk ending up in a state
// where the channel was closed in the DB, but the resolutions weren't properly
// written.
func TestChannelArbitratorEmptyResolutions(t *testing.T) {
// Start out with a log that will fail writing the set of resolutions.
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
failFetch: errNoResolutions,
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
chanArb.cfg.IsPendingClose = true
chanArb.cfg.ClosingHeight = 100
chanArb.cfg.CloseType = channeldb.RemoteForceClose
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
// It should not advance its state beyond StateContractClosed, since
// fetching resolutions fails.
chanArbCtx.AssertStateTransitions(StateContractClosed)
// It should not advance further, however, as fetching resolutions
// failed.
time.Sleep(100 * time.Millisecond)
if log.state != StateContractClosed {
t.Fatalf("expected to stay in StateContractClosed")
}
chanArb.Stop()
}
// TestChannelArbitratorAlreadyForceClosed ensures that we cannot force close a
// channel that is already in the process of doing so.
func TestChannelArbitratorAlreadyForceClosed(t *testing.T) {
t.Parallel()
// We'll create the arbitrator and its backing log to signal that it's
// already in the process of being force closed.
log := &mockArbitratorLog{
state: StateCommitmentBroadcasted,
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// Then, we'll create a request to signal a force close request to the
// channel arbitrator.
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
select {
case chanArb.forceCloseReqs <- &forceCloseReq{
closeTx: respChan,
errResp: errChan,
}:
case <-chanArb.quit:
}
// Finally, we should ensure that we are not able to do so by seeing
// the expected errAlreadyForceClosed error.
select {
case err = <-errChan:
if err != errAlreadyForceClosed {
t.Fatalf("expected errAlreadyForceClosed, got %v", err)
}
case <-time.After(time.Second):
t.Fatal("expected to receive error response")
}
}
// TestChannelArbitratorDanglingCommitForceClose tests that if there're HTLCs
// on the remote party's commitment, but not ours, and they're about to time
// out, then we'll go on chain so we can cancel back the HTLCs on the incoming
// commitment.
func TestChannelArbitratorDanglingCommitForceClose(t *testing.T) {
t.Parallel()
type testCase struct {
htlcExpired bool
remotePendingHTLC bool
confCommit HtlcSetKey
}
var testCases []testCase
testOptions := []bool{true, false}
confOptions := []HtlcSetKey{
LocalHtlcSet, RemoteHtlcSet, RemotePendingHtlcSet,
}
for _, htlcExpired := range testOptions {
for _, remotePendingHTLC := range testOptions {
for _, commitConf := range confOptions {
switch {
// If the HTLC is on the remote commitment, and
// that one confirms, then there's no special
// behavior, we should play all the HTLCs on
// that remote commitment as normal.
case !remotePendingHTLC && commitConf == RemoteHtlcSet:
fallthrough
// If the HTLC is on the remote pending, and
// that confirms, then we don't have any
// special actions.
case remotePendingHTLC && commitConf == RemotePendingHtlcSet:
continue
}
testCases = append(testCases, testCase{
htlcExpired: htlcExpired,
remotePendingHTLC: remotePendingHTLC,
confCommit: commitConf,
})
}
}
}
for _, testCase := range testCases {
testCase := testCase
testName := fmt.Sprintf("testCase: htlcExpired=%v,"+
"remotePendingHTLC=%v,remotePendingCommitConf=%v",
testCase.htlcExpired, testCase.remotePendingHTLC,
testCase.confCommit)
t.Run(testName, func(t *testing.T) {
t.Parallel()
arbLog := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
resolvers: make(map[ContractResolver]struct{}),
}
chanArbCtx, err := createTestChannelArbitrator(
t, arbLog,
)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer chanArb.Stop()
// Now that our channel arb has started, we'll set up
// its contract signals channel so we can send it
// various HTLC updates for this test.
htlcUpdates := make(chan *ContractUpdate)
signals := &ContractSignals{
HtlcUpdates: htlcUpdates,
ShortChanID: lnwire.ShortChannelID{},
}
chanArb.UpdateContractSignals(signals)
htlcKey := RemoteHtlcSet
if testCase.remotePendingHTLC {
htlcKey = RemotePendingHtlcSet
}
// Next, we'll send it a new HTLC that is set to expire
// in 10 blocks, this HTLC will only appear on the
// commitment transaction of the _remote_ party.
htlcIndex := uint64(99)
htlcExpiry := uint32(10)
danglingHTLC := channeldb.HTLC{
Incoming: false,
Amt: 10000,
HtlcIndex: htlcIndex,
RefundTimeout: htlcExpiry,
}
htlcUpdates <- &ContractUpdate{
HtlcKey: htlcKey,
Htlcs: []channeldb.HTLC{danglingHTLC},
}
// At this point, we now have a split commitment state
// from the PoV of the channel arb. There's now an HTLC
// that only exists on the commitment transaction of
// the remote party.
errChan := make(chan error, 1)
respChan := make(chan *wire.MsgTx, 1)
switch {
// If we want an HTLC expiration trigger, then We'll
// now mine a block (height 5), which is 5 blocks away
// (our grace delta) from the expiry of that HTLC.
case testCase.htlcExpired:
chanArbCtx.blockEpochs <- &chainntnfs.BlockEpoch{Height: 5}
// Otherwise, we'll just trigger a regular force close
// request.
case !testCase.htlcExpired:
chanArb.forceCloseReqs <- &forceCloseReq{
errResp: errChan,
closeTx: respChan,
}
}
// At this point, the resolver should now have
// determined that it needs to go to chain in order to
// block off the redemption path so it can cancel the
// incoming HTLC.
chanArbCtx.AssertStateTransitions(
StateBroadcastCommit,
StateCommitmentBroadcasted,
)
// Next we'll craft a fake commitment transaction to
// send to signal that the channel has closed out on
// chain.
closeTx := &wire.MsgTx{
TxIn: []*wire.TxIn{
{
PreviousOutPoint: wire.OutPoint{},
Witness: [][]byte{
{0x9},
},
},
},
}
// We'll now signal to the channel arb that the HTLC
// has fully closed on chain. Our local commit set
// shows now HTLC on our commitment, but one on the
// remote commitment. This should result in the HTLC
// being canalled back. Also note that there're no HTLC
// resolutions sent since we have none on our
// commitment transaction.
uniCloseInfo := &LocalUnilateralCloseInfo{
SpendDetail: &chainntnfs.SpendDetail{},
LocalForceCloseSummary: &lnwallet.LocalForceCloseSummary{
CloseTx: closeTx,
HtlcResolutions: &lnwallet.HtlcResolutions{},
},
ChannelCloseSummary: &channeldb.ChannelCloseSummary{},
CommitSet: CommitSet{
ConfCommitKey: &testCase.confCommit,
HtlcSets: make(map[HtlcSetKey][]channeldb.HTLC),
},
}
// If the HTLC was meant to expire, then we'll mark the
// closing transaction at the proper expiry height
// since our comparison "need to timeout" comparison is
// based on the confirmation height.
if testCase.htlcExpired {
uniCloseInfo.SpendDetail.SpendingHeight = 5
}
// Depending on if we're testing the remote pending
// commitment or not, we'll populate either a fake
// dangling remote commitment, or a regular locked in
// one.
htlcs := []channeldb.HTLC{danglingHTLC}
if testCase.remotePendingHTLC {
uniCloseInfo.CommitSet.HtlcSets[RemotePendingHtlcSet] = htlcs
} else {
uniCloseInfo.CommitSet.HtlcSets[RemoteHtlcSet] = htlcs
}
chanArb.cfg.ChainEvents.LocalUnilateralClosure <- uniCloseInfo
// The channel arb should now transition to waiting
// until the HTLCs have been fully resolved.
chanArbCtx.AssertStateTransitions(
StateContractClosed,
StateWaitingFullResolution,
)
// Now that we've sent this signal, we should have that
// HTLC be canceled back immediately.
select {
case msgs := <-chanArbCtx.resolutions:
if len(msgs) != 1 {
t.Fatalf("expected 1 message, "+
"instead got %v", len(msgs))
}
if msgs[0].HtlcIndex != htlcIndex {
t.Fatalf("wrong htlc index: expected %v, got %v",
htlcIndex, msgs[0].HtlcIndex)
}
case <-time.After(defaultTimeout):
t.Fatalf("resolution msgs not sent")
}
// There's no contract to send a fully resolve message,
// so instead, we'll mine another block which'll cause
// it to re-examine its state and realize there're no
// more HTLCs.
chanArbCtx.blockEpochs <- &chainntnfs.BlockEpoch{Height: 6}
chanArbCtx.AssertStateTransitions(StateFullyResolved)
})
}
}
// TestChannelArbitratorPendingExpiredHTLC tests that if we have pending htlc
// that is expired we will only go to chain if we are running at least the
// time defined in PaymentsExpirationGracePeriod.
// During this time the remote party is expected to send his updates and cancel
// The htlc.
func TestChannelArbitratorPendingExpiredHTLC(t *testing.T) {
t.Parallel()
// We'll create the arbitrator and its backing log in a default state.
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState, 5),
resolvers: make(map[ContractResolver]struct{}),
}
chanArbCtx, err := createTestChannelArbitrator(t, log)
if err != nil {
t.Fatalf("unable to create ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
// We'll inject a test clock implementation so we can control the uptime.
startTime := time.Date(2020, time.February, 3, 13, 0, 0, 0, time.UTC)
testClock := clock.NewTestClock(startTime)
chanArb.cfg.Clock = testClock
// We also configure the grace period and the IsForwardedHTLC to identify
// the htlc as our initiated payment.
chanArb.cfg.PaymentsExpirationGracePeriod = time.Second * 15
chanArb.cfg.IsForwardedHTLC = func(chanID lnwire.ShortChannelID,
htlcIndex uint64) bool {
return false
}
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start ChannelArbitrator: %v", err)
}
defer func() {
if err := chanArb.Stop(); err != nil {
t.Fatalf("unable to stop chan arb: %v", err)
}
}()
// Now that our channel arb has started, we'll set up
// its contract signals channel so we can send it
// various HTLC updates for this test.
htlcUpdates := make(chan *ContractUpdate)
signals := &ContractSignals{
HtlcUpdates: htlcUpdates,
ShortChanID: lnwire.ShortChannelID{},
}
chanArb.UpdateContractSignals(signals)
// Next, we'll send it a new HTLC that is set to expire
// in 10 blocks.
htlcIndex := uint64(99)
htlcExpiry := uint32(10)
pendingHTLC := channeldb.HTLC{
Incoming: false,
Amt: 10000,
HtlcIndex: htlcIndex,
RefundTimeout: htlcExpiry,
}
htlcUpdates <- &ContractUpdate{
HtlcKey: RemoteHtlcSet,
Htlcs: []channeldb.HTLC{pendingHTLC},
}
// We will advance the uptime to 10 seconds which should be still within
// the grace period and should not trigger going to chain.
testClock.SetTime(startTime.Add(time.Second * 10))
chanArbCtx.blockEpochs <- &chainntnfs.BlockEpoch{Height: 5}
chanArbCtx.AssertState(StateDefault)
// We will advance the uptime to 16 seconds which should trigger going
// to chain.
testClock.SetTime(startTime.Add(time.Second * 16))
chanArbCtx.blockEpochs <- &chainntnfs.BlockEpoch{Height: 6}
chanArbCtx.AssertStateTransitions(
StateBroadcastCommit,
StateCommitmentBroadcasted,
)
}
// TestRemoteCloseInitiator tests the setting of close initiator statuses
// for remote force closes and breaches.
func TestRemoteCloseInitiator(t *testing.T) {
// getCloseSummary returns a unilateral close summary for the channel
// provided.
getCloseSummary := func(channel *channeldb.OpenChannel) *RemoteUnilateralCloseInfo {
return &RemoteUnilateralCloseInfo{
UnilateralCloseSummary: &lnwallet.UnilateralCloseSummary{
SpendDetail: &chainntnfs.SpendDetail{
SpenderTxHash: &chainhash.Hash{},
SpendingTx: &wire.MsgTx{
TxIn: []*wire.TxIn{},
TxOut: []*wire.TxOut{},
},
},
ChannelCloseSummary: channeldb.ChannelCloseSummary{
ChanPoint: channel.FundingOutpoint,
RemotePub: channel.IdentityPub,
SettledBalance: btcutil.Amount(500),
TimeLockedBalance: btcutil.Amount(10000),
IsPending: false,
},
HtlcResolutions: &lnwallet.HtlcResolutions{},
},
}
}
tests := []struct {
name string
// notifyClose sends the appropriate chain event to indicate
// that the channel has closed. The event subscription channel
// is expected to be buffered, as is the default for test
// channel arbitrators.
notifyClose func(sub *ChainEventSubscription,
channel *channeldb.OpenChannel)
// expectedStates is the set of states we expect the arbitrator
// to progress through.
expectedStates []ArbitratorState
}{
{
name: "force close",
notifyClose: func(sub *ChainEventSubscription,
channel *channeldb.OpenChannel) {
s := getCloseSummary(channel)
sub.RemoteUnilateralClosure <- s
},
expectedStates: []ArbitratorState{
StateContractClosed, StateFullyResolved,
},
},
}
for _, test := range tests {
test := test
t.Run(test.name, func(t *testing.T) {
t.Parallel()
// First, create alice's channel.
alice, _, cleanUp, err := lnwallet.CreateTestChannels(
true,
)
if err != nil {
t.Fatalf("unable to create test channels: %v",
err)
}
defer cleanUp()
// Create a mock log which will not block the test's
// expected number of transitions transitions, and has
// no commit resolutions so that the channel will
// resolve immediately.
log := &mockArbitratorLog{
state: StateDefault,
newStates: make(chan ArbitratorState,
len(test.expectedStates)),
resolutions: &ContractResolutions{
CommitHash: chainhash.Hash{},
CommitResolution: nil,
},
}
// Mock marking the channel as closed, we only care
// about setting of channel status.
mockMarkClosed := func(_ *channeldb.ChannelCloseSummary,
statuses ...channeldb.ChannelStatus) error {
for _, status := range statuses {
err := alice.State().ApplyChanStatus(status)
if err != nil {
return err
}
}
return nil
}
chanArbCtx, err := createTestChannelArbitrator(
t, log, withMarkClosed(mockMarkClosed),
)
if err != nil {
t.Fatalf("unable to create "+
"ChannelArbitrator: %v", err)
}
chanArb := chanArbCtx.chanArb
if err := chanArb.Start(); err != nil {
t.Fatalf("unable to start "+
"ChannelArbitrator: %v", err)
}
defer func() {
if err := chanArb.Stop(); err != nil {
t.Fatal(err)
}
}()
// It should start out in the default state.
chanArbCtx.AssertState(StateDefault)
// Notify the close event.
test.notifyClose(chanArb.cfg.ChainEvents, alice.State())
// Check that the channel transitions as expected.
chanArbCtx.AssertStateTransitions(
test.expectedStates...,
)
// It should also mark the channel as resolved.
select {
case <-chanArbCtx.resolvedChan:
// Expected.
case <-time.After(defaultTimeout):
t.Fatalf("contract was not resolved")
}
// Check that alice has the status we expect.
if !alice.State().HasChanStatus(
channeldb.ChanStatusRemoteCloseInitiator,
) {
t.Fatalf("expected remote close initiator, "+
"got: %v", alice.State().ChanStatus())
}
})
}
}