Check the new feerate should be at least a 30% increase before to start timer

Author: Antoine Riard

lightning/src/ln/channel.rs

@@ -2725,7 +2725,14 @@ impl<Signer: Sign> Channel<Signer> {
 	}
 
 	/// Trigger the autoclose timer if it's in the starting position
-	pub fn maybe_trigger_autoclose_timer(&mut self) -> bool {
+	pub fn maybe_trigger_autoclose_timer(&mut self, current_feerate: u32, new_feerate: u32, background_feerate: u32) -> bool {
+
+		// Verify the new feerate is at least superior by 30% of current feerate before to
+		// start a autoclose timer.
+		if new_feerate < current_feerate * 1300 / 1000 && new_feerate < background_feerate {
+			return false;
+		}
+
 		// Start an auto-close timer, if the channel feerate doesn't increase before its
 		// expiration (i.e this outbound feerate update has been committed on both sides),
 		// the channel will be marked as unsafe and force-closed.
@@ -2985,7 +2992,7 @@ impl<Signer: Sign> Channel<Signer> {
 	/// Adds a pending update to this channel. See the doc for send_htlc for
 	/// further details on the optionness of the return value.
 	/// You MUST call send_commitment prior to any other calls on this Channel
-	fn send_update_fee(&mut self, feerate_per_kw: u32) -> Option<msgs::UpdateFee> {
+	fn send_update_fee(&mut self, feerate_per_kw: u32, background_feerate: u32) -> Option<msgs::UpdateFee> {
 		if !self.is_outbound() {
 			panic!("Cannot send fee from inbound channel");
 		}
@@ -3001,7 +3008,7 @@ impl<Signer: Sign> Channel<Signer> {
 			return None;
 		}
 
-		self.maybe_trigger_autoclose_timer();
+		self.maybe_trigger_autoclose_timer(self.get_feerate(), feerate_per_kw, background_feerate);
 
 		debug_assert!(self.pending_update_fee.is_none());
 		self.pending_update_fee = Some((feerate_per_kw, FeeUpdateState::Outbound));
@@ -3012,8 +3019,8 @@ impl<Signer: Sign> Channel<Signer> {
 		})
 	}
 
-	pub fn send_update_fee_and_commit<L: Deref>(&mut self, feerate_per_kw: u32, logger: &L) -> Result<Option<(msgs::UpdateFee, msgs::CommitmentSigned, ChannelMonitorUpdate)>, ChannelError> where L::Target: Logger {
-		match self.send_update_fee(feerate_per_kw) {
+	pub fn send_update_fee_and_commit<L: Deref>(&mut self, feerate_per_kw: u32, background_feerate: u32, logger: &L) -> Result<Option<(msgs::UpdateFee, msgs::CommitmentSigned, ChannelMonitorUpdate)>, ChannelError> where L::Target: Logger {
+		match self.send_update_fee(feerate_per_kw, background_feerate) {
 			Some(update_fee) => {
 				let (commitment_signed, monitor_update) = self.send_commitment_no_status_check(logger)?;
 				Ok(Some((update_fee, commitment_signed, monitor_update)))
@@ -3164,6 +3171,7 @@ impl<Signer: Sign> Channel<Signer> {
 		if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
 			return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned()));
 		}
+
 		Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
 		let feerate_over_dust_buffer = msg.feerate_per_kw > self.get_dust_buffer_feerate();
 

lightning/src/ln/channelmanager.rs

@@ -2828,8 +2828,9 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 		// If the channel is inbound and we detect a relevant feerate increase, we assume
 		// that our counterparty, reasonably implemented, should send us an `update_fee`
 		// soon. Monitoring this situation, we start an autoclose timer.
+		let background_feerate = self.fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
 		if !chan.is_outbound() {
-			if chan.maybe_trigger_autoclose_timer() {
+			if chan.maybe_trigger_autoclose_timer(chan.get_feerate(), new_feerate, background_feerate) {
 				return (true, NotifyOption::DoPersist, Ok(()));
 			} else {
 				return (true, NotifyOption::SkipPersist, Ok(()));
@@ -2844,7 +2845,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 			log_bytes!(chan_id[..]), chan.get_feerate(), new_feerate);
 
 		let mut retain_channel = true;
-		let res = match chan.send_update_fee_and_commit(new_feerate, &self.logger) {
+		let res = match chan.send_update_fee_and_commit(new_feerate, background_feerate, &self.logger) {
 			Ok(res) => Ok(res),
 			Err(e) => {
 				let (drop, res) = convert_chan_err!(self, e, short_to_id, chan, chan_id);