Fail back dust HTLC of local commitment tx after maturation

Author: Antoine Riard

src/ln/channelmonitor.rs

@@ -1648,14 +1648,32 @@ impl ChannelMonitor {
 	/// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
 	/// revoked using data in local_claimable_outpoints.
 	/// Should not be used if check_spend_revoked_transaction succeeds.
-	fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, (Sha256dHash, Vec<TxOut>)) {
+	fn check_spend_local_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, (Sha256dHash, Vec<TxOut>)) {
 		let commitment_txid = tx.txid();
-		// TODO: If we find a match here we need to fail back HTLCs that weren't included in the
-		// broadcast commitment transaction, either because they didn't meet dust or because they
-		// weren't yet included in our commitment transaction(s).
+
+		macro_rules! wait_threshold_conf {
+			($height: expr, $update: expr) => {
+				match self.htlc_updated_waiting_threshold_conf.entry($height + HTLC_FAIL_ANTI_REORG_DELAY - 1) {
+					hash_map::Entry::Occupied(mut entry) => {
+						entry.get_mut().push($update);
+					}
+					hash_map::Entry::Vacant(entry) => {
+						entry.insert(vec![($update)]);
+					}
+				}
+			}
+		}
+
 		if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
 			if local_tx.txid == commitment_txid {
 				log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
+				for (ref htlc, _, ref source) in &local_tx.htlc_outputs {
+					if htlc.transaction_output_index.is_none() {
+						if let Some(source) = source {
+							wait_threshold_conf!(height, (source.clone(), None, htlc.payment_hash.clone()));
+						}
+					}
+				}
 				match self.key_storage {
 					Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
 						let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
@@ -1671,6 +1689,13 @@ impl ChannelMonitor {
 		if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
 			if local_tx.txid == commitment_txid {
 				log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
+				for (ref htlc, _, ref source) in &local_tx.htlc_outputs {
+					if htlc.transaction_output_index.is_none() {
+						if let Some(source) = source {
+							wait_threshold_conf!(height, (source.clone(), None, htlc.payment_hash.clone()));
+						}
+					}
+				}
 				match self.key_storage {
 					Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
 						let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));