Merge pull request #2208 from wpaulino/monitor-rebroadcast-pending-claims

[rust-lightning] / lightning / src / chain / chainmonitor.rs

diff --git a/lightning/src/chain/chainmonitor.rs b/lightning/src/chain/chainmonitor.rs
index fdaa25f69b8ea7df39dc6b246d2f062095071019..e7c2b0f18ec001d703eb0249964b90a8a3f1a5ed 100644 (file)
--- a/lightning/src/chain/chainmonitor.rs
+++ b/lightning/src/chain/chainmonitor.rs
@@ -217,8 +217,15 @@ impl<ChannelSigner: WriteableEcdsaChannelSigner> Deref for LockedChannelMonitor<
 /// or used independently to monitor channels remotely. See the [module-level documentation] for
 /// details.
 ///
+/// Note that `ChainMonitor` should regularly trigger rebroadcasts/fee bumps of pending claims from
+/// a force-closed channel. This is crucial in preventing certain classes of pinning attacks,
+/// detecting substantial mempool feerate changes between blocks, and ensuring reliability if
+/// broadcasting fails. We recommend invoking this every 30 seconds, or lower if running in an
+/// environment with spotty connections, like on mobile.
+///
 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 /// [module-level documentation]: crate::chain::chainmonitor
+/// [`rebroadcast_pending_claims`]: Self::rebroadcast_pending_claims
 pub struct ChainMonitor<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
        where C::Target: chain::Filter,
         T::Target: BroadcasterInterface,
@@ -533,6 +540,20 @@ where C::Target: chain::Filter,
        pub fn get_update_future(&self) -> Future {
                self.event_notifier.get_future()
        }
+
+       /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
+       /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
+       /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
+       /// invoking this every 30 seconds, or lower if running in an environment with spotty
+       /// connections, like on mobile.
+       pub fn rebroadcast_pending_claims(&self) {
+               let monitors = self.monitors.read().unwrap();
+               for (_, monitor_holder) in &*monitors {
+                       monitor_holder.monitor.rebroadcast_pending_claims(
+                               &*self.broadcaster, &*self.fee_estimator, &*self.logger
+                       )
+               }
+       }
 }
 
 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>