Allow claiming a payment if a channel with an HTLC has closed
[rust-lightning] / lightning / src / ln / channelmanager.rs
index e18c133636deaff14f30eada01e6865d2a49dbfb..8b536c5dfc6464fc99e73460ec82ff86809c7fc1 100644 (file)
@@ -3981,21 +3981,10 @@ where
                };
                debug_assert!(!sources.is_empty());
 
-               // If we are claiming an MPP payment, we check that all channels which contain a claimable
-               // HTLC still exist. While this isn't guaranteed to remain true if a channel closes while
-               // we're claiming (or even after we claim, before the commitment update dance completes),
-               // it should be a relatively rare race, and we'd rather not claim HTLCs that require us to
-               // go on-chain (and lose the on-chain fee to do so) than just reject the payment.
-               //
-               // Note that we'll still always get our funds - as long as the generated
-               // `ChannelMonitorUpdate` makes it out to the relevant monitor we can claim on-chain.
-               //
-               // If we find an HTLC which we would need to claim but for which we do not have a
-               // channel, we will fail all parts of the MPP payment. While we could wait and see if
-               // the sender retries the already-failed path(s), it should be a pretty rare case where
-               // we got all the HTLCs and then a channel closed while we were waiting for the user to
-               // provide the preimage, so worrying too much about the optimal handling isn't worth
-               // it.
+               // Just in case one HTLC has been failed between when we generated the `PaymentClaimable`
+               // and when we got here we need to check that the amount we're about to claim matches the
+               // amount we told the user in the last `PaymentClaimable`. We also do a sanity-check that
+               // the MPP parts all have the same `total_msat`.
                let mut claimable_amt_msat = 0;
                let mut prev_total_msat = None;
                let mut expected_amt_msat = None;
@@ -4003,28 +3992,6 @@ where
                let mut errs = Vec::new();
                let per_peer_state = self.per_peer_state.read().unwrap();
                for htlc in sources.iter() {
-                       let (counterparty_node_id, chan_id) = match self.short_to_chan_info.read().unwrap().get(&htlc.prev_hop.short_channel_id) {
-                               Some((cp_id, chan_id)) => (cp_id.clone(), chan_id.clone()),
-                               None => {
-                                       valid_mpp = false;
-                                       break;
-                               }
-                       };
-
-                       let peer_state_mutex_opt = per_peer_state.get(&counterparty_node_id);
-                       if peer_state_mutex_opt.is_none() {
-                               valid_mpp = false;
-                               break;
-                       }
-
-                       let mut peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
-                       let peer_state = &mut *peer_state_lock;
-
-                       if peer_state.channel_by_id.get(&chan_id).is_none() {
-                               valid_mpp = false;
-                               break;
-                       }
-
                        if prev_total_msat.is_some() && prev_total_msat != Some(htlc.total_msat) {
                                log_error!(self.logger, "Somehow ended up with an MPP payment with different expected total amounts - this should not be reachable!");
                                debug_assert!(false);
@@ -6170,34 +6137,11 @@ where
                }
        }
 
-       /// Blocks until ChannelManager needs to be persisted or a timeout is reached. It returns a bool
-       /// indicating whether persistence is necessary. Only one listener on
-       /// [`await_persistable_update`], [`await_persistable_update_timeout`], or a future returned by
-       /// [`get_persistable_update_future`] is guaranteed to be woken up.
+       /// Gets a [`Future`] that completes when this [`ChannelManager`] needs to be persisted.
        ///
-       /// Note that this method is not available with the `no-std` feature.
+       /// Note that callbacks registered on the [`Future`] MUST NOT call back into this
+       /// [`ChannelManager`] and should instead register actions to be taken later.
        ///
-       /// [`await_persistable_update`]: Self::await_persistable_update
-       /// [`await_persistable_update_timeout`]: Self::await_persistable_update_timeout
-       /// [`get_persistable_update_future`]: Self::get_persistable_update_future
-       #[cfg(any(test, feature = "std"))]
-       pub fn await_persistable_update_timeout(&self, max_wait: Duration) -> bool {
-               self.persistence_notifier.wait_timeout(max_wait)
-       }
-
-       /// Blocks until ChannelManager needs to be persisted. Only one listener on
-       /// [`await_persistable_update`], `await_persistable_update_timeout`, or a future returned by
-       /// [`get_persistable_update_future`] is guaranteed to be woken up.
-       ///
-       /// [`await_persistable_update`]: Self::await_persistable_update
-       /// [`get_persistable_update_future`]: Self::get_persistable_update_future
-       pub fn await_persistable_update(&self) {
-               self.persistence_notifier.wait()
-       }
-
-       /// Gets a [`Future`] that completes when a persistable update is available. Note that
-       /// callbacks registered on the [`Future`] MUST NOT call back into this [`ChannelManager`] and
-       /// should instead register actions to be taken later.
        pub fn get_persistable_update_future(&self) -> Future {
                self.persistence_notifier.get_future()
        }
@@ -7952,6 +7896,7 @@ mod tests {
        use bitcoin::hashes::Hash;
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
+       #[cfg(feature = "std")]
        use core::time::Duration;
        use core::sync::atomic::Ordering;
        use crate::events::{Event, HTLCDestination, MessageSendEvent, MessageSendEventsProvider, ClosureReason};
@@ -7977,9 +7922,9 @@ mod tests {
 
                // All nodes start with a persistable update pending as `create_network` connects each node
                // with all other nodes to make most tests simpler.
-               assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(nodes[2].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(nodes[0].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[1].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[2].node.get_persistable_update_future().poll_is_complete());
 
                let mut chan = create_announced_chan_between_nodes(&nodes, 0, 1);
 
@@ -7993,19 +7938,19 @@ mod tests {
                        &nodes[0].node.get_our_node_id()).pop().unwrap();
 
                // The first two nodes (which opened a channel) should now require fresh persistence
-               assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(nodes[0].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[1].node.get_persistable_update_future().poll_is_complete());
                // ... but the last node should not.
-               assert!(!nodes[2].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[2].node.get_persistable_update_future().poll_is_complete());
                // After persisting the first two nodes they should no longer need fresh persistence.
-               assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[0].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[1].node.get_persistable_update_future().poll_is_complete());
 
                // Node 3, unrelated to the only channel, shouldn't care if it receives a channel_update
                // about the channel.
                nodes[2].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan.0);
                nodes[2].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan.1);
-               assert!(!nodes[2].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[2].node.get_persistable_update_future().poll_is_complete());
 
                // The nodes which are a party to the channel should also ignore messages from unrelated
                // parties.
@@ -8013,8 +7958,8 @@ mod tests {
                nodes[0].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.1);
                nodes[1].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.0);
                nodes[1].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.1);
-               assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[0].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[1].node.get_persistable_update_future().poll_is_complete());
 
                // At this point the channel info given by peers should still be the same.
                assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
@@ -8031,8 +7976,8 @@ mod tests {
                // persisted and that its channel info remains the same.
                nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &as_update);
                nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &bs_update);
-               assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[0].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[1].node.get_persistable_update_future().poll_is_complete());
                assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
                assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);
 
@@ -8040,8 +7985,8 @@ mod tests {
                // the channel info has updated.
                nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &bs_update);
                nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &as_update);
-               assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
-               assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(nodes[0].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[1].node.get_persistable_update_future().poll_is_complete());
                assert_ne!(nodes[0].node.list_channels()[0], node_a_chan_info);
                assert_ne!(nodes[1].node.list_channels()[0], node_b_chan_info);
        }