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Handle receiving channel_reestablish with next_funding_txid
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This follows the the specification closely in branching without being
too verbose, so that it should be easy to follow the logic.

See: https://github.com/lightning/bolts/blob/aa5207a/02-peer-protocol.md?plain=1#L2520-L2531
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@dunxen
dunxen committed Nov 29, 2024
1 parent 5692231 commit e1fd19d
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Showing 3 changed files with 76 additions and 8 deletions.
62 changes: 61 additions & 1 deletion lightning/src/ln/channel.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -925,6 +925,8 @@ pub(super) struct ReestablishResponses {
pub order: RAACommitmentOrder,
pub announcement_sigs: Option<msgs::AnnouncementSignatures>,
pub shutdown_msg: Option<msgs::Shutdown>,
pub tx_signatures: Option<msgs::TxSignatures>,
pub tx_abort: Option<msgs::TxAbort>,
}

/// The result of a shutdown that should be handled.
Expand Down Expand Up @@ -6388,6 +6390,8 @@ impl<SP: Deref> Channel<SP> where
raa: None, commitment_update: None,
order: RAACommitmentOrder::CommitmentFirst,
shutdown_msg, announcement_sigs,
tx_signatures: None,
tx_abort: None,
});
}

Expand All @@ -6397,6 +6401,8 @@ impl<SP: Deref> Channel<SP> where
raa: None, commitment_update: None,
order: RAACommitmentOrder::CommitmentFirst,
shutdown_msg, announcement_sigs,
tx_signatures: None,
tx_abort: None,
});
}

Expand Down Expand Up @@ -6435,7 +6441,55 @@ impl<SP: Deref> Channel<SP> where
Some(self.get_channel_ready())
} else { None };

if msg.next_local_commitment_number == next_counterparty_commitment_number {
// if next_funding_txid is set:
if let Some(next_funding_txid) = msg.next_funding_txid {
let (commitment_update, tx_signatures, tx_abort) = if let Some(session) = &self.interactive_tx_signing_session {
// if next_funding_txid matches the latest interactive funding transaction:
if session.unsigned_tx.compute_txid() == next_funding_txid {
// if it has not received tx_signatures for that funding transaction:
if !session.counterparty_sent_tx_signatures {
// MUST retransmit its commitment_signed for that funding transaction.
let commitment_signed = self.context.get_initial_commitment_signed(logger)?;
let commitment_update = Some(msgs::CommitmentUpdate {
commitment_signed,
update_add_htlcs: vec![],
update_fulfill_htlcs: vec![],
update_fail_htlcs: vec![],
update_fail_malformed_htlcs: vec![],
update_fee: None,
});
// if it has already received commitment_signed and it should sign first, as specified in the tx_signatures requirements:
if session.received_commitment_signed && session.holder_sends_tx_signatures_first {
// MUST send its tx_signatures for that funding transaction.
(commitment_update, session.holder_tx_signatures.clone(), None)
} else {
(commitment_update, None, None)
}
} else {
// if it has already received tx_signatures for that funding transaction:
// MUST send its tx_signatures for that funding transaction.
(None, session.holder_tx_signatures.clone(), None)
}
} else {
// MUST send tx_abort to let the sending node know that they can forget this funding transaction.
(None, None, Some(msgs::TxAbort { channel_id: self.context.channel_id(), data: vec![] }))
}
} else {
// Counterparty set `next_funding_txid` at incorrect state.
// TODO(dual_funding): Should probably error here (or send tx_abort) but not in spec.
(None, None, None)
};
Ok(ReestablishResponses {
channel_ready,
commitment_update,
announcement_sigs,
shutdown_msg,
tx_signatures,
tx_abort,
raa: None,
order: self.context.resend_order.clone(),
})
} else if msg.next_local_commitment_number == next_counterparty_commitment_number {
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 {
Expand All @@ -6447,6 +6501,8 @@ impl<SP: Deref> Channel<SP> where
raa: required_revoke,
commitment_update: None,
order: self.context.resend_order.clone(),
tx_signatures: None,
tx_abort: None,
})
} else if msg.next_local_commitment_number == next_counterparty_commitment_number - 1 {
if required_revoke.is_some() || self.context.signer_pending_revoke_and_ack {
Expand All @@ -6461,6 +6517,8 @@ impl<SP: Deref> Channel<SP> where
channel_ready, shutdown_msg, announcement_sigs,
commitment_update: None, raa: None,
order: self.context.resend_order.clone(),
tx_signatures: None,
tx_abort: None,
})
} else {
let commitment_update = if self.context.resend_order == RAACommitmentOrder::RevokeAndACKFirst
Expand All @@ -6483,6 +6541,8 @@ impl<SP: Deref> Channel<SP> where
channel_ready, shutdown_msg, announcement_sigs,
raa, commitment_update,
order: self.context.resend_order.clone(),
tx_signatures: None,
tx_abort: None,
})
}
} else if msg.next_local_commitment_number < next_counterparty_commitment_number {
Expand Down
16 changes: 12 additions & 4 deletions lightning/src/ln/channelmanager.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3169,7 +3169,7 @@ macro_rules! handle_monitor_update_completion {
&mut $peer_state.pending_msg_events, $chan, updates.raa,
updates.commitment_update, updates.order, updates.accepted_htlcs, updates.pending_update_adds,
updates.funding_broadcastable, updates.channel_ready,
updates.announcement_sigs, updates.tx_signatures);
updates.announcement_sigs, updates.tx_signatures, None);
if let Some(upd) = channel_update {
$peer_state.pending_msg_events.push(upd);
}
Expand Down Expand Up @@ -7403,10 +7403,10 @@ where
pending_forwards: Vec<(PendingHTLCInfo, u64)>, pending_update_adds: Vec<msgs::UpdateAddHTLC>,
funding_broadcastable: Option<Transaction>,
channel_ready: Option<msgs::ChannelReady>, announcement_sigs: Option<msgs::AnnouncementSignatures>,
tx_signatures: Option<msgs::TxSignatures>
tx_signatures: Option<msgs::TxSignatures>, tx_abort: Option<msgs::TxAbort>,
) -> (Option<(u64, Option<PublicKey>, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)>, Option<(u64, Vec<msgs::UpdateAddHTLC>)>) {
let logger = WithChannelContext::from(&self.logger, &channel.context, None);
log_trace!(logger, "Handling channel resumption for channel {} with {} RAA, {} commitment update, {} pending forwards, {} pending update_add_htlcs, {}broadcasting funding, {} channel ready, {} announcement, {} tx_signatures",
log_trace!(logger, "Handling channel resumption for channel {} with {} RAA, {} commitment update, {} pending forwards, {} pending update_add_htlcs, {}broadcasting funding, {} channel ready, {} announcement, {} tx_signatures, {} tx_abort",
&channel.context.channel_id(),
if raa.is_some() { "an" } else { "no" },
if commitment_update.is_some() { "a" } else { "no" },
Expand All @@ -7415,6 +7415,7 @@ where
if channel_ready.is_some() { "sending" } else { "without" },
if announcement_sigs.is_some() { "sending" } else { "without" },
if tx_signatures.is_some() { "sending" } else { "without" },
if tx_abort.is_some() { "sending" } else { "without" },
);

let counterparty_node_id = channel.context.get_counterparty_node_id();
Expand Down Expand Up @@ -7448,6 +7449,12 @@ where
msg,
});
}
if let Some(msg) = tx_abort {
pending_msg_events.push(events::MessageSendEvent::SendTxAbort {
node_id: counterparty_node_id,
msg,
});
}

macro_rules! handle_cs { () => {
if let Some(update) = commitment_update {
Expand Down Expand Up @@ -9246,7 +9253,8 @@ where
let need_lnd_workaround = chan.context.workaround_lnd_bug_4006.take();
let (htlc_forwards, decode_update_add_htlcs) = self.handle_channel_resumption(
&mut peer_state.pending_msg_events, chan, responses.raa, responses.commitment_update, responses.order,
Vec::new(), Vec::new(), None, responses.channel_ready, responses.announcement_sigs, None);
Vec::new(), Vec::new(), None, responses.channel_ready, responses.announcement_sigs,
responses.tx_signatures, responses.tx_abort);
debug_assert!(htlc_forwards.is_none());
debug_assert!(decode_update_add_htlcs.is_none());
if let Some(upd) = channel_update {
Expand Down
6 changes: 3 additions & 3 deletions lightning/src/ln/interactivetxs.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -291,9 +291,9 @@ impl ConstructedTransaction {
pub(crate) struct InteractiveTxSigningSession {
pub unsigned_tx: ConstructedTransaction,
pub counterparty_sent_tx_signatures: bool,
holder_sends_tx_signatures_first: bool,
received_commitment_signed: bool,
holder_tx_signatures: Option<TxSignatures>,
pub holder_sends_tx_signatures_first: bool,
pub received_commitment_signed: bool,
pub holder_tx_signatures: Option<TxSignatures>,
}

impl InteractiveTxSigningSession {
Expand Down

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