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breacharbiter: replace justice tx conf check with spend check

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Since we want to potentially broadcast multiple versions of the justice
TX, instead of waiting for confirmation of a specific TXID, we instead
wait for the breached outputs to be spent.
This commit is contained in:
Johan T. Halseth 2021-04-20 15:42:23 +02:00
parent c3b2791158
commit 3be9b74694
No known key found for this signature in database
GPG Key ID: 15BAADA29DA20D26
2 changed files with 101 additions and 83 deletions
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133
breacharbiter.go
View File

@ -538,17 +538,14 @@ func (b *breachArbiter) exactRetribution(confChan *chainntnfs.ConfirmationEvent,
defer b.wg.Done()
// TODO(roasbeef): state needs to be checkpointed here
var breachConfHeight uint32
select {
case breachConf, ok := <-confChan.Confirmed:
case _, ok := <-confChan.Confirmed:
// If the second value is !ok, then the channel has been closed
// signifying a daemon shutdown, so we exit.
if !ok {
return
}
breachConfHeight = breachConf.BlockHeight
// Otherwise, if this is a real confirmation notification, then
// we fall through to complete our duty.
case <-b.quit:
@ -570,6 +567,10 @@ func (b *breachArbiter) exactRetribution(confChan *chainntnfs.ConfirmationEvent,
return
}
// Compute both the total value of funds being swept and the
// amount of funds that were revoked from the counter party.
var totalFunds, revokedFunds btcutil.Amount
// If this retribution has not been finalized before, we will first
// construct a sweep transaction and write it to disk. This will allow
// the breach arbiter to re-register for notifications for the justice
@ -605,30 +606,49 @@ justiceTxBroadcast:
err = b.cfg.PublishTransaction(finalTx, label)
if err != nil {
brarLog.Errorf("Unable to broadcast justice tx: %v", err)
}
if err == lnwallet.ErrDoubleSpend {
// Broadcasting the transaction failed because of a
// conflict either in the mempool or in chain. We'll
// now create spend subscriptions for all HTLC outputs
// on the commitment transaction that could possibly
// have been spent, and wait for any of them to
// trigger.
brarLog.Infof("Waiting for a spend event before " +
"attempting to craft new justice tx.")
finalTx = nil
// Regardless of publication succeeded or not, we now wait for any of
// the inputs to be spent. If any input got spent by the remote, we
// must recreate our justice transaction.
var (
spendChan = make(chan []spend, 1)
errChan = make(chan error, 1)
wg sync.WaitGroup
)
spends, err := b.waitForSpendEvent(
breachInfo, spendNtfns,
)
if err != nil {
if err != errBrarShuttingDown {
brarLog.Errorf("error waiting for "+
"spend event: %v", err)
}
return
wg.Add(1)
go func() {
defer wg.Done()
spends, err := b.waitForSpendEvent(breachInfo, spendNtfns)
if err != nil {
errChan <- err
return
}
spendChan <- spends
}()
Loop:
for {
select {
case spends := <-spendChan:
// Print the funds swept by the txs.
for _, s := range spends {
tx := s.detail.SpendingTx
t, r := countRevokedFunds(breachInfo, tx)
totalFunds += t
revokedFunds += r
}
brarLog.Infof("Justice for ChannelPoint(%v) has "+
"been served, %v revoked funds (%v total) "+
"have been claimed", breachInfo.chanPoint,
revokedFunds, totalFunds)
// Update the breach info with the new spends.
updateBreachInfo(breachInfo, spends)
if len(breachInfo.breachedOutputs) == 0 {
brarLog.Debugf("No more outputs to sweep for "+
"breach, marking ChannelPoint(%v) "+
@ -640,63 +660,36 @@ justiceTxBroadcast:
"breached ChannelPoint(%v): %v",
breachInfo.chanPoint, err)
}
return
// TODO(roasbeef): add peer to blacklist?
// TODO(roasbeef): close other active channels with offending
// peer
break Loop
}
finalTx = nil
brarLog.Infof("Attempting another justice tx "+
"with %d inputs",
len(breachInfo.breachedOutputs))
wg.Wait()
goto justiceTxBroadcast
case err := <-errChan:
if err != errBrarShuttingDown {
brarLog.Errorf("error waiting for "+
"spend event: %v", err)
}
break Loop
case <-b.quit:
break Loop
}
}
// As a conclusionary step, we register for a notification to be
// dispatched once the justice tx is confirmed. After confirmation we
// notify the caller that initiated the retribution workflow that the
// deed has been done.
justiceTXID := finalTx.TxHash()
justiceScript := finalTx.TxOut[0].PkScript
confChan, err = b.cfg.Notifier.RegisterConfirmationsNtfn(
&justiceTXID, justiceScript, 1, breachConfHeight,
)
if err != nil {
brarLog.Errorf("Unable to register for conf for txid(%v): %v",
justiceTXID, err)
return
}
select {
case _, ok := <-confChan.Confirmed:
if !ok {
return
}
// Compute both the total value of funds being swept and the
// amount of funds that were revoked from the counter party.
totalFunds, revokedFunds := countRevokedFunds(breachInfo, finalTx)
brarLog.Infof("Justice for ChannelPoint(%v) has "+
"been served, %v revoked funds (%v total) "+
"have been claimed", breachInfo.chanPoint,
revokedFunds, totalFunds)
err = b.cleanupBreach(&breachInfo.chanPoint)
if err != nil {
brarLog.Errorf("Failed to cleanup breached "+
"ChannelPoint(%v): %v", breachInfo.chanPoint,
err)
}
// TODO(roasbeef): add peer to blacklist?
// TODO(roasbeef): close other active channels with offending
// peer
return
case <-b.quit:
return
}
// Wait for our go routine to exit.
wg.Wait()
}
// countRevokedFunds counts the total and revoked funds swept by our justice

51
breacharbiter_test.go
View File

@ -1222,7 +1222,7 @@ func TestBreachHandoffFail(t *testing.T) {
}
type publAssertion func(*testing.T, map[wire.OutPoint]struct{},
chan *wire.MsgTx, chainhash.Hash)
chan *wire.MsgTx, chainhash.Hash) *wire.MsgTx
type breachTest struct {
name string
@ -1361,7 +1361,7 @@ var breachTests = []breachTest{
spend2ndLevel: true,
whenNonZeroInputs: func(t *testing.T,
inputs map[wire.OutPoint]struct{},
publTx chan *wire.MsgTx, _ chainhash.Hash) {
publTx chan *wire.MsgTx, _ chainhash.Hash) *wire.MsgTx {
var tx *wire.MsgTx
select {
@ -1384,10 +1384,11 @@ var breachTests = []breachTest{
findInputIndex(t, in, tx)
}
return tx
},
whenZeroInputs: func(t *testing.T,
inputs map[wire.OutPoint]struct{},
publTx chan *wire.MsgTx, _ chainhash.Hash) {
publTx chan *wire.MsgTx, _ chainhash.Hash) *wire.MsgTx {
// Sanity check to ensure the brar doesn't try to
// broadcast another sweep, since all outputs have been
@ -1397,6 +1398,8 @@ var breachTests = []breachTest{
t.Fatalf("tx published unexpectedly")
case <-time.After(50 * time.Millisecond):
}
return nil
},
},
{
@ -1405,7 +1408,7 @@ var breachTests = []breachTest{
sendFinalConf: true,
whenNonZeroInputs: func(t *testing.T,
inputs map[wire.OutPoint]struct{},
publTx chan *wire.MsgTx, _ chainhash.Hash) {
publTx chan *wire.MsgTx, _ chainhash.Hash) *wire.MsgTx {
var tx *wire.MsgTx
select {
@ -1428,11 +1431,12 @@ var breachTests = []breachTest{
findInputIndex(t, in, tx)
}
return tx
},
whenZeroInputs: func(t *testing.T,
inputs map[wire.OutPoint]struct{},
publTx chan *wire.MsgTx,
htlc2ndLevlTxHash chainhash.Hash) {
htlc2ndLevlTxHash chainhash.Hash) *wire.MsgTx {
// Now a transaction attempting to spend from the second
// level tx should be published instead. Let this
@ -1465,6 +1469,8 @@ var breachTests = []breachTest{
t.Fatalf("tx not attempting to spend second "+
"level tx, %v", tx.TxIn[0])
}
return tx
},
},
{ // nolint: dupl
@ -1474,7 +1480,7 @@ var breachTests = []breachTest{
sweepHtlc: true,
whenNonZeroInputs: func(t *testing.T,
inputs map[wire.OutPoint]struct{},
publTx chan *wire.MsgTx, _ chainhash.Hash) {
publTx chan *wire.MsgTx, _ chainhash.Hash) *wire.MsgTx {
var tx *wire.MsgTx
select {
@ -1496,10 +1502,12 @@ var breachTests = []breachTest{
for in := range inputs {
findInputIndex(t, in, tx)
}
return tx
},
whenZeroInputs: func(t *testing.T,
inputs map[wire.OutPoint]struct{},
publTx chan *wire.MsgTx, _ chainhash.Hash) {
publTx chan *wire.MsgTx, _ chainhash.Hash) *wire.MsgTx {
// Sanity check to ensure the brar doesn't try to
// broadcast another sweep, since all outputs have been
@ -1509,6 +1517,8 @@ var breachTests = []breachTest{
t.Fatalf("tx published unexpectedly")
case <-time.After(50 * time.Millisecond):
}
return nil
},
},
}
@ -1567,7 +1577,11 @@ func testBreachSpends(t *testing.T, test breachTest) {
},
BreachRetribution: retribution,
}
contractBreaches <- breach
select {
case contractBreaches <- breach:
case <-time.After(15 * time.Second):
t.Fatalf("breach not delivered")
}
// We'll also wait to consume the ACK back from the breach arbiter.
select {
@ -1608,7 +1622,12 @@ func testBreachSpends(t *testing.T, test breachTest) {
// Notify that the breaching transaction is confirmed, to trigger the
// retribution logic.
notifier := brar.cfg.Notifier.(*mock.SpendNotifier)
notifier.ConfChan <- &chainntnfs.TxConfirmation{}
select {
case notifier.ConfChan <- &chainntnfs.TxConfirmation{}:
case <-time.After(15 * time.Second):
t.Fatalf("conf not delivered")
}
// The breach arbiter should attempt to sweep all outputs on the
// breached commitment. We'll pretend that the HTLC output has been
@ -1666,6 +1685,7 @@ func testBreachSpends(t *testing.T, test breachTest) {
// Until no more inputs to spend remain, deliver the spend events and
// process the assertions prescribed by the test case.
var justiceTx *wire.MsgTx
for len(spentBy) > 0 {
var (
op wire.OutPoint
@ -1705,20 +1725,25 @@ func testBreachSpends(t *testing.T, test breachTest) {
}
if len(spentBy) > 0 {
test.whenNonZeroInputs(t, inputsToSweep, publTx, htlc2ndLevlTx.TxHash())
justiceTx = test.whenNonZeroInputs(t, inputsToSweep, publTx, htlc2ndLevlTx.TxHash())
} else {
// Reset the publishing error so that any publication,
// made by the breach arbiter, if any, will succeed.
publMtx.Lock()
publErr = nil
publMtx.Unlock()
test.whenZeroInputs(t, inputsToSweep, publTx, htlc2ndLevlTx.TxHash())
justiceTx = test.whenZeroInputs(t, inputsToSweep, publTx, htlc2ndLevlTx.TxHash())
}
}
// Deliver confirmation of sweep if the test expects it.
// Deliver confirmation of sweep if the test expects it. Since we are
// looking for the final justice tx to confirme, we deliver a spend of
// all its inputs.
if test.sendFinalConf {
notifier.ConfChan <- &chainntnfs.TxConfirmation{}
for _, txin := range justiceTx.TxIn {
op := txin.PreviousOutPoint
notifier.Spend(&op, 3, justiceTx)
}
}
// Assert that the channel is fully resolved.