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Allow failing revoke_and_ack if commitment point is not available
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@alecchendev
alecchendev committed Jul 15, 2024
1 parent 1f7f3a3 commit 614da40
Showing 1 changed file with 51 additions and 19 deletions.
70 changes: 51 additions & 19 deletions lightning/src/ln/channel.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5363,16 +5363,21 @@ impl<SP: Deref> Channel<SP> where
}

let mut raa = if self.context.monitor_pending_revoke_and_ack {
Some(self.get_last_revoke_and_ack())
self.get_last_revoke_and_ack(logger)
} else { None };
let commitment_update = if self.context.monitor_pending_commitment_signed {
let mut commitment_update = if self.context.monitor_pending_commitment_signed {
self.get_last_commitment_update_for_send(logger).ok()
} else { None };
if self.context.resend_order == RAACommitmentOrder::CommitmentFirst
&& self.context.signer_pending_commitment_update && raa.is_some() {
self.context.signer_pending_revoke_and_ack = true;
raa = None;
}
if self.context.resend_order == RAACommitmentOrder::RevokeAndACKFirst
&& self.context.signer_pending_revoke_and_ack && commitment_update.is_some() {
self.context.signer_pending_commitment_update = true;
commitment_update = None;
}

if commitment_update.is_some() {
self.mark_awaiting_response();
Expand Down Expand Up @@ -5443,6 +5448,10 @@ impl<SP: Deref> Channel<SP> where
/// blocked.
#[cfg(async_signing)]
pub fn signer_maybe_unblocked<L: Deref>(&mut self, logger: &L) -> SignerResumeUpdates where L::Target: Logger {
if !self.context.holder_commitment_point.is_available() {
log_trace!(logger, "Attempting to update holder per-commitment point...");
self.context.holder_commitment_point.try_resolve_pending(&self.context.holder_signer, &self.context.secp_ctx, logger);
}
let funding_signed = if self.context.signer_pending_funding && !self.context.is_outbound() {
self.context.get_funding_signed_msg(logger).1
} else { None };
Expand All @@ -5456,7 +5465,7 @@ impl<SP: Deref> Channel<SP> where
} else { None };
let mut revoke_and_ack = if self.context.signer_pending_revoke_and_ack {
log_trace!(logger, "Attempting to generate pending revoke and ack...");
Some(self.get_last_revoke_and_ack())
self.get_last_revoke_and_ack(logger)
} else { None };

if self.context.resend_order == RAACommitmentOrder::CommitmentFirst
Expand Down Expand Up @@ -5488,19 +5497,35 @@ impl<SP: Deref> Channel<SP> where
}
}

fn get_last_revoke_and_ack(&mut self) -> msgs::RevokeAndACK {
debug_assert!(self.context.holder_commitment_point.transaction_number() <= INITIAL_COMMITMENT_NUMBER + 2);
// TODO: handle non-available case when get_per_commitment_point becomes async
debug_assert!(self.context.holder_commitment_point.is_available());
let next_per_commitment_point = self.context.holder_commitment_point.current_point();
fn get_last_revoke_and_ack<L: Deref>(&mut self, logger: &L) -> Option<msgs::RevokeAndACK> where L::Target: Logger {
debug_assert!(self.context.holder_commitment_point.transaction_number() <= INITIAL_COMMITMENT_NUMBER - 2);
self.context.holder_commitment_point.try_resolve_pending(&self.context.holder_signer, &self.context.secp_ctx, logger);
let per_commitment_secret = self.context.holder_signer.as_ref().release_commitment_secret(self.context.holder_commitment_point.transaction_number() + 2);
self.context.signer_pending_revoke_and_ack = false;
msgs::RevokeAndACK {
channel_id: self.context.channel_id,
per_commitment_secret,
next_per_commitment_point,
#[cfg(taproot)]
next_local_nonce: None,
if let HolderCommitmentPoint::Available { transaction_number: _, current, next: _ } = self.context.holder_commitment_point {
self.context.signer_pending_revoke_and_ack = false;
Some(msgs::RevokeAndACK {
channel_id: self.context.channel_id,
per_commitment_secret,
next_per_commitment_point: current,
#[cfg(taproot)]
next_local_nonce: None,
})
} else {
#[cfg(not(async_signing))] {
panic!("Holder commitment point must be Available when generating revoke_and_ack");
}
#[cfg(async_signing)] {
// Technically if we're at HolderCommitmentPoint::PendingNext,
// we have a commitment point ready to send in an RAA, however we
// choose to wait since if we send RAA now, we could get another
// CS before we have any commitment point available. Blocking our
// RAA here is a convenient way to make sure that post-funding
// we're only ever waiting on one commitment point at a time.
log_trace!(logger, "Last revoke-and-ack pending in channel {} for sequence {} because the next per-commitment point is not available",
&self.context.channel_id(), self.context.holder_commitment_point.transaction_number());
self.context.signer_pending_revoke_and_ack = true;
None
}
}
}

Expand Down Expand Up @@ -5708,7 +5733,7 @@ impl<SP: Deref> Channel<SP> where
self.context.monitor_pending_revoke_and_ack = true;
None
} else {
Some(self.get_last_revoke_and_ack())
self.get_last_revoke_and_ack(logger)
}
} else {
debug_assert!(false, "All values should have been handled in the four cases above");
Expand All @@ -5735,7 +5760,7 @@ impl<SP: Deref> Channel<SP> where
} else { None };

if msg.next_local_commitment_number == next_counterparty_commitment_number {
if required_revoke.is_some() {
if required_revoke.is_some() || self.context.signer_pending_revoke_and_ack {
log_debug!(logger, "Reconnected channel {} with only lost outbound RAA", &self.context.channel_id());
} else {
log_debug!(logger, "Reconnected channel {} with no loss", &self.context.channel_id());
Expand All @@ -5748,7 +5773,7 @@ impl<SP: Deref> Channel<SP> where
order: self.context.resend_order.clone(),
})
} else if msg.next_local_commitment_number == next_counterparty_commitment_number - 1 {
if required_revoke.is_some() {
if required_revoke.is_some() || self.context.signer_pending_revoke_and_ack {
log_debug!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx", &self.context.channel_id());
} else {
log_debug!(logger, "Reconnected channel {} with only lost remote commitment tx", &self.context.channel_id());
Expand All @@ -5762,7 +5787,14 @@ impl<SP: Deref> Channel<SP> where
order: self.context.resend_order.clone(),
})
} else {
let commitment_update = self.get_last_commitment_update_for_send(logger).ok();
let commitment_update = if self.context.resend_order == RAACommitmentOrder::RevokeAndACKFirst
&& self.context.signer_pending_revoke_and_ack {
log_trace!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx, but unable to send due to resend order, waiting on signer for revoke and ack", &self.context.channel_id());
self.context.signer_pending_commitment_update = true;
None
} else {
self.get_last_commitment_update_for_send(logger).ok()
};
let raa = if self.context.resend_order == RAACommitmentOrder::CommitmentFirst
&& self.context.signer_pending_commitment_update && required_revoke.is_some() {
log_trace!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx, but unable to send due to resend order, waiting on signer for commitment update", &self.context.channel_id());
Expand Down

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