Check outbound update_fee affordance incremented with holding cell HTLCs

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index fcb13031ac62274146e8461cb13fa17d5278be21..35aac0471ea2790f6517ab3d8e6f1797651fc8a0 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -294,6 +294,7 @@ struct HTLCStats {
        on_counterparty_tx_dust_exposure_msat: u64,
        on_holder_tx_dust_exposure_msat: u64,
        holding_cell_msat: u64,
+       on_holder_tx_holding_cell_htlcs_count: u32, // dust HTLCs *non*-included
 }
 
 /// An enum gathering stats on commitment transaction, either local or remote.
@@ -2024,6 +2025,7 @@ impl<Signer: Sign> Channel<Signer> {
                        on_counterparty_tx_dust_exposure_msat: 0,
                        on_holder_tx_dust_exposure_msat: 0,
                        holding_cell_msat: 0,
+                       on_holder_tx_holding_cell_htlcs_count: 0,
                };
 
                let counterparty_dust_limit_timeout_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
@@ -2048,6 +2050,7 @@ impl<Signer: Sign> Channel<Signer> {
                        on_counterparty_tx_dust_exposure_msat: 0,
                        on_holder_tx_dust_exposure_msat: 0,
                        holding_cell_msat: 0,
+                       on_holder_tx_holding_cell_htlcs_count: 0,
                };
 
                let counterparty_dust_limit_success_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
@@ -2072,6 +2075,8 @@ impl<Signer: Sign> Channel<Signer> {
                                }
                                if *amount_msat / 1000 < holder_dust_limit_timeout_sat {
                                        stats.on_holder_tx_dust_exposure_msat += amount_msat;
+                               } else {
+                                       stats.on_holder_tx_holding_cell_htlcs_count += 1;
                                }
                        }
                }
@@ -3099,7 +3104,7 @@ impl<Signer: Sign> Channel<Signer> {
                let outbound_stats = self.get_outbound_pending_htlc_stats(Some(feerate_per_kw));
                let keys = if let Ok(keys) = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number) { keys } else { return None; };
                let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
-               let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize) * 1000;
+               let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize) * 1000;
                let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
                if holder_balance_msat < buffer_fee_msat  + self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
                        //TODO: auto-close after a number of failures?