Generalize do_chain_event signature for splicing

When processing confirmed transactions and updates to the best block,
ChannelManager may be instructed to send a channel_ready message when a
channel's funding transaction has confirmed and has met the required
number of confirmations. A similar action is needed for sending
splice_locked once splice transaction has confirmed with required number
of confirmations. Generalize do_chain_event signature to allow for
either scenario.

Author: jkczyz

lightning/src/ln/channel.rs

@@ -50,9 +50,9 @@ use crate::ln::channel_state::{
 	OutboundHTLCDetails, OutboundHTLCStateDetails,
 };
 use crate::ln::channelmanager::{
-	self, HTLCFailureMsg, HTLCSource, OpenChannelMessage, PaymentClaimDetails, PendingHTLCInfo,
-	PendingHTLCStatus, RAACommitmentOrder, SentHTLCId, BREAKDOWN_TIMEOUT,
-	MAX_LOCAL_BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA,
+	self, FundingConfirmedMessage, HTLCFailureMsg, HTLCSource, OpenChannelMessage,
+	PaymentClaimDetails, PendingHTLCInfo, PendingHTLCStatus, RAACommitmentOrder, SentHTLCId,
+	BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA,
 };
 use crate::ln::interactivetxs::{
 	calculate_change_output_value, get_output_weight, AbortReason, HandleTxCompleteResult,
@@ -8814,7 +8814,7 @@ where
 	pub fn transactions_confirmed<NS: Deref, L: Deref>(
 		&mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData,
 		chain_hash: ChainHash, node_signer: &NS, user_config: &UserConfig, logger: &L
-	) -> Result<(Option<msgs::ChannelReady>, Option<msgs::AnnouncementSignatures>), ClosureReason>
+	) -> Result<(Option<FundingConfirmedMessage>, Option<msgs::AnnouncementSignatures>), ClosureReason>
 	where
 		NS::Target: NodeSigner,
 		L::Target: Logger
@@ -8875,7 +8875,7 @@ where
 					if let Some(channel_ready) = self.check_get_channel_ready(height, logger) {
 						log_info!(logger, "Sending a channel_ready to our peer for channel {}", &self.context.channel_id);
 						let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, height, logger);
-						msgs = (Some(channel_ready), announcement_sigs);
+						msgs = (Some(FundingConfirmedMessage::Establishment(channel_ready)), announcement_sigs);
 					}
 				}
 				for inp in tx.input.iter() {
@@ -8904,7 +8904,7 @@ where
 	pub fn best_block_updated<NS: Deref, L: Deref>(
 		&mut self, height: u32, highest_header_time: u32, chain_hash: ChainHash,
 		node_signer: &NS, user_config: &UserConfig, logger: &L
-	) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
+	) -> Result<(Option<FundingConfirmedMessage>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
 	where
 		NS::Target: NodeSigner,
 		L::Target: Logger
@@ -8916,7 +8916,7 @@ where
 	fn do_best_block_updated<NS: Deref, L: Deref>(
 		&mut self, height: u32, highest_header_time: u32,
 		chain_node_signer: Option<(ChainHash, &NS, &UserConfig)>, logger: &L
-	) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
+	) -> Result<(Option<FundingConfirmedMessage>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
 	where
 		NS::Target: NodeSigner,
 		L::Target: Logger
@@ -8945,7 +8945,7 @@ where
 				self.get_announcement_sigs(node_signer, chain_hash, user_config, height, logger)
 			} else { None };
 			log_info!(logger, "Sending a channel_ready to our peer for channel {}", &self.context.channel_id);
-			return Ok((Some(channel_ready), timed_out_htlcs, announcement_sigs));
+			return Ok((Some(FundingConfirmedMessage::Establishment(channel_ready)), timed_out_htlcs, announcement_sigs));
 		}
 
 		if matches!(self.context.channel_state, ChannelState::ChannelReady(_)) ||

lightning/src/ln/channelmanager.rs

@@ -11962,6 +11962,10 @@ where
 	}
 }
 
+pub(super) enum FundingConfirmedMessage {
+	Establishment(msgs::ChannelReady),
+}
+
 impl<
 		M: Deref,
 		T: Deref,
@@ -11988,7 +11992,7 @@ where
 	/// un/confirmed, etc) on each channel, handling any resulting errors or messages generated by
 	/// the function.
 	#[rustfmt::skip]
-	fn do_chain_event<FN: Fn(&mut FundedChannel<SP>) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>>
+	fn do_chain_event<FN: Fn(&mut FundedChannel<SP>) -> Result<(Option<FundingConfirmedMessage>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>>
 			(&self, height_opt: Option<u32>, f: FN) {
 		// Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
 		// during initialization prior to the chain_monitor being fully configured in some cases.
@@ -12009,27 +12013,30 @@ where
 						None => true,
 						Some(funded_channel) => {
 							let res = f(funded_channel);
-							if let Ok((channel_ready_opt, mut timed_out_pending_htlcs, announcement_sigs)) = res {
+							if let Ok((funding_confirmed_opt, mut timed_out_pending_htlcs, announcement_sigs)) = res {
 								for (source, payment_hash) in timed_out_pending_htlcs.drain(..) {
 									let reason = LocalHTLCFailureReason::CLTVExpiryTooSoon;
 									let data = self.get_htlc_inbound_temp_fail_data(reason);
 									timed_out_htlcs.push((source, payment_hash, HTLCFailReason::reason(reason, data),
 										HTLCHandlingFailureType::Forward { node_id: Some(funded_channel.context.get_counterparty_node_id()), channel_id: funded_channel.context.channel_id() }));
 								}
 								let logger = WithChannelContext::from(&self.logger, &funded_channel.context, None);
-								if let Some(channel_ready) = channel_ready_opt {
-									send_channel_ready!(self, pending_msg_events, funded_channel, channel_ready);
-									if funded_channel.context.is_usable() {
-										log_trace!(logger, "Sending channel_ready with private initial channel_update for our counterparty on channel {}", funded_channel.context.channel_id());
-										if let Ok(msg) = self.get_channel_update_for_unicast(funded_channel) {
-											pending_msg_events.push(MessageSendEvent::SendChannelUpdate {
-												node_id: funded_channel.context.get_counterparty_node_id(),
-												msg,
-											});
+								match funding_confirmed_opt {
+									Some(FundingConfirmedMessage::Establishment(channel_ready)) => {
+										send_channel_ready!(self, pending_msg_events, funded_channel, channel_ready);
+										if funded_channel.context.is_usable() {
+											log_trace!(logger, "Sending channel_ready with private initial channel_update for our counterparty on channel {}", funded_channel.context.channel_id());
+											if let Ok(msg) = self.get_channel_update_for_unicast(funded_channel) {
+												pending_msg_events.push(MessageSendEvent::SendChannelUpdate {
+													node_id: funded_channel.context.get_counterparty_node_id(),
+													msg,
+												});
+											}
+										} else {
+											log_trace!(logger, "Sending channel_ready WITHOUT channel_update for {}", funded_channel.context.channel_id());
 										}
-									} else {
-										log_trace!(logger, "Sending channel_ready WITHOUT channel_update for {}", funded_channel.context.channel_id());
-									}
+									},
+									None => {},
 								}
 
 								{