From 47f70dae3a9ae4913606ae245aed51a79acf1faf Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Wed, 1 Mar 2023 22:15:17 -0800
Subject: [PATCH] contractcourt: update commitSweepResolver for taproot chans
---
contractcourt/commit_sweep_resolver.go | 80 +++++++++++++++++++-------
1 file changed, 58 insertions(+), 22 deletions(-)
diff --git a/contractcourt/commit_sweep_resolver.go b/contractcourt/commit_sweep_resolver.go
index ea78bbbac..839a0025e 100644
--- a/contractcourt/commit_sweep_resolver.go
+++ b/contractcourt/commit_sweep_resolver.go
@@ -57,6 +57,9 @@ type commitSweepResolver struct {
// leased channel.
leaseExpiry uint32
+ // chanType denotes the type of channel the contract belongs to.
+ chanType channeldb.ChannelType
+
// currentReport stores the current state of the resolver for reporting
// over the rpc interface.
currentReport ContractReport
@@ -148,13 +151,15 @@ func waitForSpend(op *wire.OutPoint, pkScript []byte, heightHint uint32,
}
}
-// getCommitTxConfHeight waits for confirmation of the commitment tx and returns
-// the confirmation height.
+// getCommitTxConfHeight waits for confirmation of the commitment tx and
+// returns the confirmation height.
func (c *commitSweepResolver) getCommitTxConfHeight() (uint32, error) {
txID := c.commitResolution.SelfOutPoint.Hash
signDesc := c.commitResolution.SelfOutputSignDesc
pkScript := signDesc.Output.PkScript
+
const confDepth = 1
+
confChan, err := c.Notifier.RegisterConfirmationsNtfn(
&txID, pkScript, confDepth, c.broadcastHeight,
)
@@ -245,23 +250,50 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
}
}
+ var (
+ isLocalCommitTx bool
+
+ signDesc = c.commitResolution.SelfOutputSignDesc
+ )
+ switch {
+ // For taproot channels, we'll know if this is the local commit based
+ // on the witness script. For local channels, the witness script has an
+ // OP_DROP value.
+ //
+ // TODO(roasbeef): revisit this after the script changes
+ // * otherwise need to base off the key in script or the CSV value
+ // (script num encode)
+ case c.chanType.IsTaproot():
+ scriptLen := len(signDesc.WitnessScript)
+ isLocalCommitTx = signDesc.WitnessScript[scriptLen-1] ==
+ txscript.OP_DROP
+
// The output is on our local commitment if the script starts with
// OP_IF for the revocation clause. On the remote commitment it will
// either be a regular P2WKH or a simple sig spend with a CSV delay.
- isLocalCommitTx := c.commitResolution.SelfOutputSignDesc.WitnessScript[0] == txscript.OP_IF
+ default:
+ isLocalCommitTx = signDesc.WitnessScript[0] == txscript.OP_IF
+ }
isDelayedOutput := c.commitResolution.MaturityDelay != 0
c.log.Debugf("isDelayedOutput=%v, isLocalCommitTx=%v", isDelayedOutput,
isLocalCommitTx)
- // There're three types of commitments, those that have tweaks
- // for the remote key (us in this case), those that don't, and a third
- // where there is no tweak and the output is delayed. On the local
- // commitment our output will always be delayed. We'll rely on the
- // presence of the commitment tweak to to discern which type of
- // commitment this is.
+ // There're three types of commitments, those that have tweaks for the
+ // remote key (us in this case), those that don't, and a third where
+ // there is no tweak and the output is delayed. On the local commitment
+ // our output will always be delayed. We'll rely on the presence of the
+ // commitment tweak to to discern which type of commitment this is.
var witnessType input.WitnessType
switch {
+ // The local delayed output for a taproot channel.
+ case isLocalCommitTx && c.chanType.IsTaproot():
+ witnessType = input.TaprootLocalCommitSpend
+
+ // The CSV 1 delayed output for a taproot channel.
+ case !isLocalCommitTx && c.chanType.IsTaproot():
+ witnessType = input.TaprootRemoteCommitSpend
+
// Delayed output to us on our local commitment for a channel lease in
// which we are the initiator.
case isLocalCommitTx && c.hasCLTV():
@@ -293,9 +325,9 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
c.log.Infof("Sweeping with witness type: %v", witnessType)
- // We'll craft an input with all the information required for
- // the sweeper to create a fully valid sweeping transaction to
- // recover these coins.
+ // We'll craft an input with all the information required for the
+ // sweeper to create a fully valid sweeping transaction to recover
+ // these coins.
var inp *input.BaseInput
if c.hasCLTV() {
inp = input.NewCsvInputWithCltv(
@@ -312,6 +344,9 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
)
}
+ // TODO(roasbeef): instead of ading ctrl block to the sign desc, make
+ // new input type, have sweeper set it?
+
// With our input constructed, we'll now offer it to the
// sweeper.
c.log.Infof("sweeping commit output")
@@ -326,28 +361,28 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
var sweepTxID chainhash.Hash
- // Sweeper is going to join this input with other inputs if
- // possible and publish the sweep tx. When the sweep tx
- // confirms, it signals us through the result channel with the
- // outcome. Wait for this to happen.
+ // Sweeper is going to join this input with other inputs if possible
+ // and publish the sweep tx. When the sweep tx confirms, it signals us
+ // through the result channel with the outcome. Wait for this to
+ // happen.
outcome := channeldb.ResolverOutcomeClaimed
select {
case sweepResult := <-resultChan:
switch sweepResult.Err {
+ // If the remote party was able to sweep this output it's
+ // likely what we sent was actually a revoked commitment.
+ // Report the error and continue to wrap up the contract.
case sweep.ErrRemoteSpend:
- // If the remote party was able to sweep this output
- // it's likely what we sent was actually a revoked
- // commitment. Report the error and continue to wrap up
- // the contract.
c.log.Warnf("local commitment output was swept by "+
"remote party via %v", sweepResult.Tx.TxHash())
outcome = channeldb.ResolverOutcomeUnclaimed
+
+ // No errors, therefore continue processing.
case nil:
- // No errors, therefore continue processing.
c.log.Infof("local commitment output fully resolved by "+
"sweep tx: %v", sweepResult.Tx.TxHash())
+ // Unknown errors.
default:
- // Unknown errors.
c.log.Errorf("unable to sweep input: %v",
sweepResult.Err)
@@ -404,6 +439,7 @@ func (c *commitSweepResolver) SupplementState(state *channeldb.OpenChannel) {
c.leaseExpiry = state.ThawHeight
}
c.channelInitiator = state.IsInitiator
+ c.chanType = state.ChanType
}
// hasCLTV denotes whether the resolver must wait for an additional CLTV to