Skip to content

Introduce RenegotiatedFundingLocked monitor update variant #3894

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
60 changes: 57 additions & 3 deletions lightning/src/chain/channelmonitor.rs
Original file line number Diff line number Diff line change
Expand Up @@ -676,6 +676,9 @@ pub(crate) enum ChannelMonitorUpdateStep {
holder_commitment_tx: HolderCommitmentTransaction,
counterparty_commitment_tx: CommitmentTransaction,
},
RenegotiatedFundingLocked {
funding_txid: Txid,
},
}

impl ChannelMonitorUpdateStep {
Expand All @@ -690,6 +693,7 @@ impl ChannelMonitorUpdateStep {
ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
ChannelMonitorUpdateStep::RenegotiatedFunding { .. } => "RenegotiatedFunding",
ChannelMonitorUpdateStep::RenegotiatedFundingLocked { .. } => "RenegotiatedFundingLocked",
}
}
}
Expand Down Expand Up @@ -733,6 +737,9 @@ impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
(3, holder_commitment_tx, required),
(5, counterparty_commitment_tx, required),
},
(12, RenegotiatedFundingLocked) => {
(1, funding_txid, required),
},
);

/// Indicates whether the balance is derived from a cooperative close, a force-close
Expand Down Expand Up @@ -1075,6 +1082,10 @@ impl FundingScope {
fn funding_txid(&self) -> Txid {
self.funding_outpoint().txid
}

fn is_splice(&self) -> bool {
self.channel_parameters.splice_parent_funding_txid.is_some()
}
}

impl Writeable for FundingScope {
Expand Down Expand Up @@ -1209,8 +1220,6 @@ pub(crate) struct ChannelMonitorImpl<Signer: EcdsaChannelSigner> {
// interface knows about the TXOs that we want to be notified of spends of. We could probably
// be smart and derive them from the above storage fields, but its much simpler and more
// Obviously Correct (tm) if we just keep track of them explicitly.
//
// TODO: Remove entries for stale funding transactions on `splice_locked`.
outputs_to_watch: HashMap<Txid, Vec<(u32, ScriptBuf)>>,

#[cfg(any(test, feature = "_test_utils"))]
Expand Down Expand Up @@ -3670,6 +3679,10 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
);
return Err(());
}
} else if self.funding.is_splice() {
// If we've already spliced at least once, we're no longer able to RBF the original
// funding transaction.
return Err(());
}

self.outputs_to_watch.insert(
Expand All @@ -3681,6 +3694,39 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
Ok(())
}

fn promote_funding(&mut self, new_funding_txid: Txid) -> Result<(), ()> {
let is_pending_splice = self.pending_funding.iter().any(|funding| funding.is_splice());

let new_funding = self
.pending_funding
.iter_mut()
.find(|funding| funding.funding_txid() == new_funding_txid);
if new_funding.is_none() {
return Err(());
}
let mut new_funding = new_funding.unwrap();

// `first_confirmed_funding_txo` is set to the first outpoint for the channel upon init.
// If an RBF happens and it confirms, this will no longer be accurate, so update it now
// if we know the RBF doesn't belong to a splice.
if !is_pending_splice && self.first_confirmed_funding_txo == self.funding.funding_outpoint()
{
self.first_confirmed_funding_txo = new_funding.funding_outpoint();
}

mem::swap(&mut self.funding, &mut new_funding);
self.onchain_tx_handler.update_after_renegotiated_funding_locked(
self.funding.current_holder_commitment_tx.clone(),
self.funding.prev_holder_commitment_tx.clone(),
);

for funding in self.pending_funding.drain(..) {
self.outputs_to_watch.remove(&funding.funding_txid());
}

Ok(())
}

#[rustfmt::skip]
fn update_monitor<B: Deref, F: Deref, L: Deref>(
&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &WithChannelMonitor<L>
Expand Down Expand Up @@ -3771,6 +3817,13 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
ret = Err(());
}
},
ChannelMonitorUpdateStep::RenegotiatedFundingLocked { funding_txid } => {
log_trace!(logger, "Updating ChannelMonitor with locked renegotiated funding txid {}", funding_txid);
if let Err(_) = self.promote_funding(*funding_txid) {
log_error!(logger, "Unknown funding with txid {} became locked", funding_txid);
ret = Err(());
}
},
ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
self.lockdown_from_offchain = true;
Expand Down Expand Up @@ -3823,7 +3876,8 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
|ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTX { .. }
|ChannelMonitorUpdateStep::ShutdownScript { .. }
|ChannelMonitorUpdateStep::CommitmentSecret { .. }
|ChannelMonitorUpdateStep::RenegotiatedFunding { .. } =>
|ChannelMonitorUpdateStep::RenegotiatedFunding { .. }
|ChannelMonitorUpdateStep::RenegotiatedFundingLocked { .. } =>
is_pre_close_update = true,
// After a channel is closed, we don't communicate with our peer about it, so the
// only things we will update is getting a new preimage (from a different channel)
Expand Down
9 changes: 9 additions & 0 deletions lightning/src/chain/onchaintx.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1216,6 +1216,15 @@ impl<ChannelSigner: EcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
}

/// Replaces the current/prev holder commitment transactions spending the currently confirmed
/// funding outpoint with those spending the new funding outpoint.
pub(crate) fn update_after_renegotiated_funding_locked(
&mut self, current: HolderCommitmentTransaction, prev: Option<HolderCommitmentTransaction>,
) {
self.holder_commitment = current;
self.prev_holder_commitment = prev;
}

// Deprecated as of 0.2, only use in cases where it was not previously available.
pub(crate) fn channel_parameters(&self) -> &ChannelTransactionParameters {
&self.channel_transaction_parameters
Expand Down
Loading
Loading