contractcourt/chain_watcher: handleUnknownRemoteState
This commit extracts the data loss protect recovery procedure into its own method.
This commit is contained in:
Johan T. Halseth
parent
743ea7be74
commit
93d917d82a
@ -613,78 +613,25 @@ func (c *chainWatcher) closeObserver(spendNtfn *chainntnfs.SpendEvent) {
|
||||
log.Warnf("Unprompted commitment broadcast for "+
|
||||
"ChannelPoint(%v) ", c.cfg.chanState.FundingOutpoint)
|
||||
|
||||
// If this channel has been recovered, then we'll modify our
|
||||
// behavior as it isn't possible for us to close out the
|
||||
// channel off-chain ourselves. It can only be the remote party
|
||||
// force closing, or a cooperative closure we signed off on
|
||||
// before losing data getting confirmed in the chain.
|
||||
isRecoveredChan := c.cfg.chanState.HasChanStatus(
|
||||
channeldb.ChanStatusRestored,
|
||||
// Since it was neither a known remote state, nor a local state
|
||||
// that was published, it most likely mean we lost state and
|
||||
// the remote node closed. In this case we must start the DLP
|
||||
// protocol in hope of getting our money back.
|
||||
ok, err = c.handleUnknownRemoteState(
|
||||
commitSpend, broadcastStateNum, chainSet,
|
||||
)
|
||||
|
||||
switch {
|
||||
// If the remote party has broadcasted a state beyond our best
|
||||
// known state for them, and they don't have a pending
|
||||
// commitment (we write them to disk before sending out), then
|
||||
// this means that we've lost data. In this case, we'll enter
|
||||
// the DLP protocol. Otherwise, if we've recovered our channel
|
||||
// state from scratch, then we don't know what the precise
|
||||
// current state is, so we assume either the remote party
|
||||
// forced closed or we've been breached. In the latter case,
|
||||
// our tower will take care of us.
|
||||
case broadcastStateNum > chainSet.remoteStateNum || isRecoveredChan:
|
||||
log.Warnf("Remote node broadcast state #%v, "+
|
||||
"which is more than 1 beyond best known "+
|
||||
"state #%v!!! Attempting recovery...",
|
||||
broadcastStateNum, chainSet.remoteStateNum)
|
||||
|
||||
// If this isn't a tweakless commitment, then we'll
|
||||
// need to wait for the remote party's latest unrevoked
|
||||
// commitment point to be presented to us as we need
|
||||
// this to sweep. Otherwise, we can dispatch the remote
|
||||
// close and sweep immediately using a fake commitPoint
|
||||
// as it isn't actually needed for recovery anymore.
|
||||
commitPoint := c.cfg.chanState.RemoteCurrentRevocation
|
||||
tweaklessCommit := c.cfg.chanState.ChanType.IsTweakless()
|
||||
if !tweaklessCommit {
|
||||
commitPoint = c.waitForCommitmentPoint()
|
||||
if commitPoint == nil {
|
||||
if err != nil {
|
||||
log.Errorf("Unable to handle unknown remote state: %v",
|
||||
err)
|
||||
return
|
||||
}
|
||||
|
||||
log.Infof("Recovered commit point(%x) for "+
|
||||
"channel(%v)! Now attempting to use it to "+
|
||||
"sweep our funds...",
|
||||
commitPoint.SerializeCompressed(),
|
||||
c.cfg.chanState.FundingOutpoint)
|
||||
|
||||
} else {
|
||||
log.Infof("ChannelPoint(%v) is tweakless, "+
|
||||
"moving to sweep directly on chain",
|
||||
c.cfg.chanState.FundingOutpoint)
|
||||
if ok {
|
||||
return
|
||||
}
|
||||
|
||||
// Since we don't have the commitment stored for this
|
||||
// state, we'll just pass an empty commitment within
|
||||
// the commitment set. Note that this means we won't be
|
||||
// able to recover any HTLC funds.
|
||||
//
|
||||
// TODO(halseth): can we try to recover some HTLCs?
|
||||
chainSet.commitSet.ConfCommitKey = &RemoteHtlcSet
|
||||
err = c.dispatchRemoteForceClose(
|
||||
commitSpend, channeldb.ChannelCommitment{},
|
||||
chainSet.commitSet, commitPoint,
|
||||
)
|
||||
if err != nil {
|
||||
log.Errorf("unable to handle remote "+
|
||||
"close for chan_point=%v: %v",
|
||||
c.cfg.chanState.FundingOutpoint, err)
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
// Now that a spend has been detected, we've done our job, so
|
||||
// we'll exit immediately.
|
||||
log.Warnf("Unable to handle spending tx %v of channel point %v",
|
||||
commitTxBroadcast.TxHash(), c.cfg.chanState.FundingOutpoint)
|
||||
return
|
||||
|
||||
// The chainWatcher has been signalled to exit, so we'll do so now.
|
||||
@ -834,6 +781,64 @@ func (c *chainWatcher) handleKnownRemoteState(
|
||||
return true, nil
|
||||
}
|
||||
|
||||
// handleUnknownRemoteState is the last attempt we make at reclaiming funds
|
||||
// from the closed channel, by checkin whether the passed spend _could_ be a
|
||||
// remote spend that is unknown to us (we lost state). We will try to initiate
|
||||
// Data Loss Protection in order to restore our commit point and reclaim our
|
||||
// funds from the channel. If we are not able to act on it, false is returned.
|
||||
func (c *chainWatcher) handleUnknownRemoteState(
|
||||
commitSpend *chainntnfs.SpendDetail, broadcastStateNum uint64,
|
||||
chainSet *chainSet) (bool, error) {
|
||||
|
||||
log.Warnf("Remote node broadcast state #%v, "+
|
||||
"which is more than 1 beyond best known "+
|
||||
"state #%v!!! Attempting recovery...",
|
||||
broadcastStateNum, chainSet.remoteStateNum)
|
||||
|
||||
// If this isn't a tweakless commitment, then we'll need to wait for
|
||||
// the remote party's latest unrevoked commitment point to be presented
|
||||
// to us as we need this to sweep. Otherwise, we can dispatch the
|
||||
// remote close and sweep immediately using a fake commitPoint as it
|
||||
// isn't actually needed for recovery anymore.
|
||||
commitPoint := c.cfg.chanState.RemoteCurrentRevocation
|
||||
tweaklessCommit := c.cfg.chanState.ChanType.IsTweakless()
|
||||
if !tweaklessCommit {
|
||||
commitPoint = c.waitForCommitmentPoint()
|
||||
if commitPoint == nil {
|
||||
return false, fmt.Errorf("unable to get commit point")
|
||||
}
|
||||
|
||||
log.Infof("Recovered commit point(%x) for "+
|
||||
"channel(%v)! Now attempting to use it to "+
|
||||
"sweep our funds...",
|
||||
commitPoint.SerializeCompressed(),
|
||||
c.cfg.chanState.FundingOutpoint)
|
||||
|
||||
} else {
|
||||
log.Infof("ChannelPoint(%v) is tweakless, "+
|
||||
"moving to sweep directly on chain",
|
||||
c.cfg.chanState.FundingOutpoint)
|
||||
}
|
||||
|
||||
// Since we don't have the commitment stored for this state, we'll just
|
||||
// pass an empty commitment within the commitment set. Note that this
|
||||
// means we won't be able to recover any HTLC funds.
|
||||
//
|
||||
// TODO(halseth): can we try to recover some HTLCs?
|
||||
chainSet.commitSet.ConfCommitKey = &RemoteHtlcSet
|
||||
err := c.dispatchRemoteForceClose(
|
||||
commitSpend, channeldb.ChannelCommitment{},
|
||||
chainSet.commitSet, commitPoint,
|
||||
)
|
||||
if err != nil {
|
||||
return false, fmt.Errorf("unable to handle remote "+
|
||||
"close for chan_point=%v: %v",
|
||||
c.cfg.chanState.FundingOutpoint, err)
|
||||
}
|
||||
|
||||
return true, nil
|
||||
}
|
||||
|
||||
// toSelfAmount takes a transaction and returns the sum of all outputs that pay
|
||||
// to a script that the wallet controls. If no outputs pay to us, then we
|
||||
// return zero. This is possible as our output may have been trimmed due to
|
||||
|
||||
Loading…
Reference in New Issue
Block a user