Skip to content

Allow counterparty tx_abort before handling initial commitment signed #4204

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.

Sign up for GitHub

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

Merged
merged 2 commits into from
Nov 9, 2025
+243 −44
Merged

Allow counterparty tx_abort before handling initial commitment signed #4204

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
0cdcf54
Support capturing `tx_abort` send within channel reestablish tests
wpaulino Nov 3, 2025
d282a47
Allow counterparty tx_abort before handling initial commitment signed
wpaulino Nov 3, 2025
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
17 changes: 11 additions & 6 deletions lightning/src/ln/async_signer_tests.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -596,7 +596,7 @@ fn do_test_async_raa_peer_disconnect(
}

// Expect the RAA
let (_, revoke_and_ack, commitment_signed, resend_order, _, _, _) =
let (_, revoke_and_ack, commitment_signed, resend_order, _, _, _, _) =
handle_chan_reestablish_msgs!(dst, src);
if test_case == UnblockSignerAcrossDisconnectCase::AtEnd {
assert!(revoke_and_ack.is_none());
Expand All @@ -612,14 +612,14 @@ fn do_test_async_raa_peer_disconnect(
dst.node.signer_unblocked(Some((src_node_id, chan_id)));

if test_case == UnblockSignerAcrossDisconnectCase::AtEnd {
let (_, revoke_and_ack, commitment_signed, resend_order, _, _, _) =
let (_, revoke_and_ack, commitment_signed, resend_order, _, _, _, _) =
handle_chan_reestablish_msgs!(dst, src);
assert!(revoke_and_ack.is_some());
assert!(commitment_signed.is_some());
assert!(resend_order == RAACommitmentOrder::RevokeAndACKFirst);
} else {
// Make sure we don't double send the RAA.
let (_, revoke_and_ack, commitment_signed, _, _, _, _) =
let (_, revoke_and_ack, commitment_signed, _, _, _, _, _) =
handle_chan_reestablish_msgs!(dst, src);
assert!(revoke_and_ack.is_none());
assert!(commitment_signed.is_none());
Expand Down Expand Up @@ -746,7 +746,7 @@ fn do_test_async_commitment_signature_peer_disconnect(
}

// Expect the RAA
let (_, revoke_and_ack, commitment_signed, _, _, _, _) =
let (_, revoke_and_ack, commitment_signed, _, _, _, _, _) =
handle_chan_reestablish_msgs!(dst, src);
assert!(revoke_and_ack.is_some());
if test_case == UnblockSignerAcrossDisconnectCase::AtEnd {
Expand All @@ -760,11 +760,11 @@ fn do_test_async_commitment_signature_peer_disconnect(
dst.node.signer_unblocked(Some((src_node_id, chan_id)));

if test_case == UnblockSignerAcrossDisconnectCase::AtEnd {
let (_, _, commitment_signed, _, _, _, _) = handle_chan_reestablish_msgs!(dst, src);
let (_, _, commitment_signed, _, _, _, _, _) = handle_chan_reestablish_msgs!(dst, src);
assert!(commitment_signed.is_some());
} else {
// Make sure we don't double send the CS.
let (_, _, commitment_signed, _, _, _, _) = handle_chan_reestablish_msgs!(dst, src);
let (_, _, commitment_signed, _, _, _, _, _) = handle_chan_reestablish_msgs!(dst, src);
assert!(commitment_signed.is_none());
}
}
Expand Down Expand Up @@ -882,6 +882,7 @@ fn do_test_async_commitment_signature_ordering(monitor_update_failure: bool) {
assert!(as_resp.4.is_none());
assert!(as_resp.5.is_none());
assert!(as_resp.6.is_none());
assert!(as_resp.7.is_none());

if monitor_update_failure {
chanmon_cfgs[0].persister.set_update_ret(ChannelMonitorUpdateStatus::Completed);
Expand All @@ -904,6 +905,7 @@ fn do_test_async_commitment_signature_ordering(monitor_update_failure: bool) {
assert!(as_resp.4.is_none());
assert!(as_resp.5.is_none());
assert!(as_resp.6.is_none());
assert!(as_resp.7.is_none());

nodes[0].enable_channel_signer_op(&node_b_id, &chan_id, SignerOp::SignCounterpartyCommitment);
nodes[0].node.signer_unblocked(Some((node_b_id, chan_id)));
Expand All @@ -929,6 +931,9 @@ fn do_test_async_commitment_signature_ordering(monitor_update_failure: bool) {
assert!(as_resp.6.is_none());
assert!(bs_resp.6.is_none());

assert!(as_resp.7.is_none());
assert!(bs_resp.7.is_none());

// Now that everything is restored, get the CS + RAA and handle them.
nodes[1]
.node
Expand Down
104 changes: 72 additions & 32 deletions lightning/src/ln/channel.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1654,7 +1654,7 @@ where
}
chan.context.channel_state.clear_local_stfu_sent();
chan.context.channel_state.clear_remote_stfu_sent();
if chan.should_reset_pending_splice_state() {
if chan.should_reset_pending_splice_state(false) {
// If there was a pending splice negotiation that failed due to disconnecting, we
// also take the opportunity to clean up our state.
let splice_funding_failed = chan.reset_pending_splice_state();
Expand Down Expand Up @@ -1775,7 +1775,7 @@ where
None
},
ChannelPhase::Funded(funded_channel) => {
if funded_channel.should_reset_pending_splice_state() {
if funded_channel.should_reset_pending_splice_state(false) {
funded_channel.reset_pending_splice_state()
} else {
debug_assert!(false, "We should never fail an interactive funding negotiation once we're exchanging tx_signatures");
Expand Down Expand Up @@ -1932,12 +1932,24 @@ where
(had_constructor, None)
},
ChannelPhase::Funded(funded_channel) => {
if funded_channel.has_pending_splice_awaiting_signatures() {
if funded_channel.has_pending_splice_awaiting_signatures()
&& funded_channel
.context()
.interactive_tx_signing_session
.as_ref()
.expect("We have a pending splice awaiting signatures")
.has_received_commitment_signed()
{
// We only force close once the counterparty tries to abort after committing to
Copy link
Collaborator

@TheBlueMatt TheBlueMatt Nov 9, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This implies that this is somehow a limitation in LDK, but it isn't, its a rather fundamental limitation of the protocol - if we have received the CS, the peer cannot know whether we have provided them with funding signatures, at which point cancelling the splice would be unsafe no matter the implementation in LDK.

// the splice via their initial `commitment_signed`. This is because our monitor
// state is updated with the post-splice commitment transaction upon receiving
// their `commitment_signed`, so we would need another monitor update to abandon
// it, which we don't currently support.
return Err(ChannelError::close(
"Received tx_abort while awaiting tx_signatures exchange".to_owned(),
));
}
if funded_channel.should_reset_pending_splice_state() {
if funded_channel.should_reset_pending_splice_state(true) {
let has_funding_negotiation = funded_channel
.pending_splice
.as_ref()
Expand Down Expand Up @@ -2681,19 +2693,6 @@ impl FundingNegotiation {
}

impl PendingFunding {
fn can_abandon_state(&self) -> bool {
self.funding_negotiation
.as_ref()
.map(|funding_negotiation| {
!matches!(funding_negotiation, FundingNegotiation::AwaitingSignatures { .. })
})
.unwrap_or_else(|| {
let has_negotiated_candidates = !self.negotiated_candidates.is_empty();
debug_assert!(has_negotiated_candidates);
!has_negotiated_candidates
})
}

fn check_get_splice_locked<SP: Deref>(
&mut self, context: &ChannelContext<SP>, confirmed_funding_index: usize, height: u32,
) -> Option<msgs::SpliceLocked>
Expand Down Expand Up @@ -6873,7 +6872,7 @@ pub struct SpliceFundingFailed {
}

macro_rules! maybe_create_splice_funding_failed {
($pending_splice: expr, $get: ident, $contributed_inputs_and_outputs: ident) => {{
($funded_channel: expr, $pending_splice: expr, $get: ident, $contributed_inputs_and_outputs: ident) => {{
$pending_splice
.and_then(|pending_splice| pending_splice.funding_negotiation.$get())
.filter(|funding_negotiation| funding_negotiation.is_initiator())
Expand All @@ -6895,10 +6894,12 @@ macro_rules! maybe_create_splice_funding_failed {
interactive_tx_constructor,
..
} => interactive_tx_constructor.$contributed_inputs_and_outputs(),
FundingNegotiation::AwaitingSignatures { .. } => {
debug_assert!(false);
(Vec::new(), Vec::new())
},
FundingNegotiation::AwaitingSignatures { .. } => $funded_channel
.context
.interactive_tx_signing_session
.$get()
.expect("We have a pending splice awaiting signatures")
.$contributed_inputs_and_outputs(),
};

SpliceFundingFailed {
Expand Down Expand Up @@ -6937,7 +6938,7 @@ where

fn maybe_fail_splice_negotiation(&mut self) -> Option<SpliceFundingFailed> {
if matches!(self.context.channel_state, ChannelState::ChannelReady(_)) {
if self.should_reset_pending_splice_state() {
if self.should_reset_pending_splice_state(false) {
self.reset_pending_splice_state()
} else {
match self.quiescent_action.take() {
Expand Down Expand Up @@ -7011,19 +7012,54 @@ where

/// Returns a boolean indicating whether we should reset the splice's
/// [`PendingFunding::funding_negotiation`].
fn should_reset_pending_splice_state(&self) -> bool {
fn should_reset_pending_splice_state(&self, counterparty_aborted: bool) -> bool {
self.pending_splice
.as_ref()
.map(|pending_splice| pending_splice.can_abandon_state())
.map(|pending_splice| {
pending_splice
.funding_negotiation
.as_ref()
.map(|funding_negotiation| {
let is_awaiting_signatures = matches!(
funding_negotiation,
FundingNegotiation::AwaitingSignatures { .. }
);
if counterparty_aborted {
Copy link
Contributor

@jkczyz jkczyz Nov 5, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Why do we condition on counterparty_aborted? Would it be a problem if always do the new check?

Copy link
Contributor Author

@wpaulino wpaulino Nov 6, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If we don't, then we would always reset the splice state when we haven't received their initial commitment_signed.

!is_awaiting_signatures
|| !self
.context()
.interactive_tx_signing_session
.as_ref()
.expect("We have a pending splice awaiting signatures")
.has_received_commitment_signed()
} else {
!is_awaiting_signatures
}
})
.unwrap_or_else(|| {
let has_negotiated_candidates =
!pending_splice.negotiated_candidates.is_empty();
debug_assert!(has_negotiated_candidates);
!has_negotiated_candidates
})
})
.unwrap_or(false)
}

fn reset_pending_splice_state(&mut self) -> Option<SpliceFundingFailed> {
debug_assert!(self.should_reset_pending_splice_state());
debug_assert!(self.context.interactive_tx_signing_session.is_none());
self.context.channel_state.clear_quiescent();
debug_assert!(self.should_reset_pending_splice_state(true));
debug_assert!(
self.context.interactive_tx_signing_session.is_none()
|| !self
.context
.interactive_tx_signing_session
.as_ref()
.expect("We have a pending splice awaiting signatures")
.has_received_commitment_signed()
);

let splice_funding_failed = maybe_create_splice_funding_failed!(
self,
self.pending_splice.as_mut(),
take,
into_contributed_inputs_and_outputs
Expand All @@ -7033,15 +7069,19 @@ where
self.pending_splice.take();
}

self.context.channel_state.clear_quiescent();
self.context.interactive_tx_signing_session.take();

splice_funding_failed
}

pub(super) fn maybe_splice_funding_failed(&self) -> Option<SpliceFundingFailed> {
if !self.should_reset_pending_splice_state() {
if !self.should_reset_pending_splice_state(false) {
return None;
}

maybe_create_splice_funding_failed!(
self,
self.pending_splice.as_ref(),
as_ref,
to_contributed_inputs_and_outputs
Expand Down Expand Up @@ -11996,7 +12036,7 @@ where
pub fn abandon_splice(
&mut self,
) -> Result<(msgs::TxAbort, Option<SpliceFundingFailed>), APIError> {
if self.should_reset_pending_splice_state() {
if self.should_reset_pending_splice_state(false) {
let tx_abort =
msgs::TxAbort { channel_id: self.context.channel_id(), data: Vec::new() };
let splice_funding_failed = self.reset_pending_splice_state();
Expand Down Expand Up @@ -14361,7 +14401,7 @@ where
}
channel_state.clear_local_stfu_sent();
channel_state.clear_remote_stfu_sent();
if self.should_reset_pending_splice_state()
if self.should_reset_pending_splice_state(false)
|| !self.has_pending_splice_awaiting_signatures()
{
// We shouldn't be quiescent anymore upon reconnecting if:
Expand Down Expand Up @@ -14735,7 +14775,7 @@ where
// We don't have to worry about resetting the pending `FundingNegotiation` because we
// can only read `FundingNegotiation::AwaitingSignatures` variants anyway.
let pending_splice =
self.pending_splice.as_ref().filter(|_| !self.should_reset_pending_splice_state());
self.pending_splice.as_ref().filter(|_| !self.should_reset_pending_splice_state(false));

write_tlv_fields!(writer, {
(0, self.context.announcement_sigs, option),
Expand Down
26 changes: 25 additions & 1 deletion lightning/src/ln/functional_test_utils.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4996,9 +4996,17 @@ macro_rules! handle_chan_reestablish_msgs {
($src_node: expr, $dst_node: expr) => {{
let msg_events = $src_node.node.get_and_clear_pending_msg_events();
let mut idx = 0;

let mut tx_abort = None;
if let Some(&MessageSendEvent::SendTxAbort { ref node_id, ref msg }) = msg_events.get(idx) {
idx += 1;
assert_eq!(*node_id, $dst_node.node.get_our_node_id());
tx_abort = Some(msg.clone());
}

let channel_ready =
if let Some(&MessageSendEvent::SendChannelReady { ref node_id, ref msg }) =
msg_events.get(0)
msg_events.get(idx)
{
idx += 1;
assert_eq!(*node_id, $dst_node.node.get_our_node_id());
Expand Down Expand Up @@ -5115,6 +5123,7 @@ macro_rules! handle_chan_reestablish_msgs {
announcement_sigs,
tx_signatures,
stfu,
tx_abort,
)
}};
}
Expand All @@ -5127,6 +5136,7 @@ pub struct ReconnectArgs<'a, 'b, 'c, 'd> {
pub send_stfu: (bool, bool),
pub send_interactive_tx_commit_sig: (bool, bool),
pub send_interactive_tx_sigs: (bool, bool),
pub send_tx_abort: (bool, bool),
pub expect_renegotiated_funding_locked_monitor_update: (bool, bool),
pub pending_responding_commitment_signed: (bool, bool),
/// Indicates that the pending responding commitment signed will be a dup for the recipient,
Expand All @@ -5150,6 +5160,7 @@ impl<'a, 'b, 'c, 'd> ReconnectArgs<'a, 'b, 'c, 'd> {
send_stfu: (false, false),
send_interactive_tx_commit_sig: (false, false),
send_interactive_tx_sigs: (false, false),
send_tx_abort: (false, false),
expect_renegotiated_funding_locked_monitor_update: (false, false),
pending_responding_commitment_signed: (false, false),
pending_responding_commitment_signed_dup_monitor: (false, false),
Expand All @@ -5174,6 +5185,7 @@ pub fn reconnect_nodes<'a, 'b, 'c, 'd>(args: ReconnectArgs<'a, 'b, 'c, 'd>) {
send_stfu,
send_interactive_tx_commit_sig,
send_interactive_tx_sigs,
send_tx_abort,
expect_renegotiated_funding_locked_monitor_update,
pending_htlc_adds,
pending_htlc_claims,
Expand Down Expand Up @@ -5305,6 +5317,12 @@ pub fn reconnect_nodes<'a, 'b, 'c, 'd>(args: ReconnectArgs<'a, 'b, 'c, 'd>) {
&commitment_update.commitment_signed,
)
}
if send_tx_abort.0 {
let tx_abort = chan_msgs.7.take().unwrap();
node_a.node.handle_tx_abort(node_b_id, &tx_abort);
} else {
assert!(chan_msgs.7.is_none());
}
if send_interactive_tx_sigs.0 {
let tx_signatures = chan_msgs.5.take().unwrap();
node_a.node.handle_tx_signatures(node_b_id, &tx_signatures);
Expand Down Expand Up @@ -5417,6 +5435,12 @@ pub fn reconnect_nodes<'a, 'b, 'c, 'd>(args: ReconnectArgs<'a, 'b, 'c, 'd>) {
&commitment_update.commitment_signed,
)
}
if send_tx_abort.1 {
let tx_abort = chan_msgs.7.take().unwrap();
node_a.node.handle_tx_abort(node_b_id, &tx_abort);
} else {
assert!(chan_msgs.7.is_none());
}
if send_interactive_tx_sigs.1 {
let tx_signatures = chan_msgs.5.take().unwrap();
node_b.node.handle_tx_signatures(node_a_id, &tx_signatures);
Expand Down
Loading
Loading