Adds DiscardFunding event
author1nF0rmed <prkinformed@gmail.com>
Mon, 27 Sep 2021 16:50:07 +0000 (22:20 +0530)
committer1nF0rmed <prkinformed@gmail.com>
Sat, 9 Oct 2021 11:13:50 +0000 (16:43 +0530)
During the event of a channel close, if the funding transaction
is yet to be broadcasted then a DiscardFunding event is issued
along with the ChannelClose event.

lightning/src/ln/channel.rs
lightning/src/ln/channelmanager.rs
lightning/src/ln/functional_test_utils.rs
lightning/src/ln/functional_tests.rs
lightning/src/util/events.rs

index 858e307b77e429a6c992c0759bcdf751148ac251..936bbab7cc5912841de3c99a3bbdf68e8689fa0c 100644 (file)
@@ -1901,6 +1901,15 @@ impl<Signer: Sign> Channel<Signer> {
                Ok(())
        }
 
+       /// Returns transaction if there is pending funding transaction that is yet to broadcast
+       pub fn unbroadcasted_funding(&self) -> Option<Transaction> {
+                if self.channel_state & (ChannelState::FundingCreated as u32) != 0 {
+                        self.funding_transaction.clone()
+                } else {
+                        None
+                }
+       }
+
        /// Returns a HTLCStats about inbound pending htlcs
        fn get_inbound_pending_htlc_stats(&self) -> HTLCStats {
                let mut stats = HTLCStats {
index a4684bfe6cc2960438bfdc9e2e575ed2b7aa2f79..5e43158b1c9c63d4da2400858f4060b55474efa4 100644 (file)
@@ -1326,6 +1326,18 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                self.list_channels_with_filter(|&(_, ref channel)| channel.is_live())
        }
 
+       /// Helper function that issues the channel close events
+       fn issue_channel_close_events(&self, channel: &Channel<Signer>, closure_reason: ClosureReason) {
+               let mut pending_events_lock = self.pending_events.lock().unwrap();
+               match channel.unbroadcasted_funding() {
+                       Some(transaction) => {
+                               pending_events_lock.push(events::Event::DiscardFunding { channel_id: channel.channel_id(), transaction })
+                       },
+                       None => {},
+               }
+               pending_events_lock.push(events::Event::ChannelClosed { channel_id: channel.channel_id(), reason: closure_reason });
+       }
+
        fn close_channel_internal(&self, channel_id: &[u8; 32], target_feerate_sats_per_1000_weight: Option<u32>) -> Result<(), APIError> {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
@@ -1372,12 +1384,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                msg: channel_update
                                                        });
                                                }
-                                               if let Ok(mut pending_events_lock) = self.pending_events.lock() {
-                                                       pending_events_lock.push(events::Event::ChannelClosed {
-                                                               channel_id: *channel_id,
-                                                               reason: ClosureReason::HolderForceClosed
-                                                       });
-                                               }
+                                               self.issue_channel_close_events(&channel, ClosureReason::HolderForceClosed);
                                        }
                                        break Ok(());
                                },
@@ -1468,13 +1475,12 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                if let Some(short_id) = chan.get().get_short_channel_id() {
                                        channel_state.short_to_id.remove(&short_id);
                                }
-                               let mut pending_events_lock = self.pending_events.lock().unwrap();
                                if peer_node_id.is_some() {
                                        if let Some(peer_msg) = peer_msg {
-                                               pending_events_lock.push(events::Event::ChannelClosed { channel_id: *channel_id, reason: ClosureReason::CounterpartyForceClosed { peer_msg: peer_msg.to_string() } });
+                                               self.issue_channel_close_events(chan.get(),ClosureReason::CounterpartyForceClosed { peer_msg: peer_msg.to_string() });
                                        }
                                } else {
-                                       pending_events_lock.push(events::Event::ChannelClosed { channel_id: *channel_id, reason: ClosureReason::HolderForceClosed });
+                                       self.issue_channel_close_events(chan.get(),ClosureReason::HolderForceClosed);
                                }
                                chan.remove_entry().1
                        } else {
@@ -3574,7 +3580,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        msg: update
                                });
                        }
-                       self.pending_events.lock().unwrap().push(events::Event::ChannelClosed { channel_id: msg.channel_id,  reason: ClosureReason::CooperativeClosure });
+                       self.issue_channel_close_events(&chan, ClosureReason::CooperativeClosure);
                }
                Ok(())
        }
@@ -3986,7 +3992,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                msg: update
                                                        });
                                                }
-                                               self.pending_events.lock().unwrap().push(events::Event::ChannelClosed { channel_id: chan.channel_id(),  reason: ClosureReason::CommitmentTxConfirmed });
+                                               self.issue_channel_close_events(&chan, ClosureReason::CommitmentTxConfirmed);
                                                pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                        node_id: chan.get_counterparty_node_id(),
                                                        action: msgs::ErrorAction::SendErrorMessage {
@@ -4102,12 +4108,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                });
                                                        }
 
-                                                       if let Ok(mut pending_events_lock) = self.pending_events.lock() {
-                                                               pending_events_lock.push(events::Event::ChannelClosed {
-                                                                       channel_id: *channel_id,
-                                                                       reason: ClosureReason::CooperativeClosure
-                                                               });
-                                                       }
+                                                       self.issue_channel_close_events(chan, ClosureReason::CooperativeClosure);
 
                                                        log_info!(self.logger, "Broadcasting {}", log_tx!(tx));
                                                        self.tx_broadcaster.broadcast_transaction(&tx);
@@ -4529,7 +4530,7 @@ where
                                                        msg: update
                                                });
                                        }
-                                       self.pending_events.lock().unwrap().push(events::Event::ChannelClosed { channel_id: channel.channel_id(),  reason: ClosureReason::CommitmentTxConfirmed });
+                                       self.issue_channel_close_events(channel, ClosureReason::CommitmentTxConfirmed);
                                        pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                node_id: channel.get_counterparty_node_id(),
                                                action: msgs::ErrorAction::SendErrorMessage { msg: e },
@@ -4720,7 +4721,7 @@ impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
                                                                msg: update
                                                        });
                                                }
-                                               self.pending_events.lock().unwrap().push(events::Event::ChannelClosed { channel_id: chan.channel_id(),  reason: ClosureReason::DisconnectedPeer });
+                                               self.issue_channel_close_events(chan, ClosureReason::DisconnectedPeer);
                                                false
                                        } else {
                                                true
@@ -4735,7 +4736,7 @@ impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
                                                        if let Some(short_id) = chan.get_short_channel_id() {
                                                                short_to_id.remove(&short_id);
                                                        }
-                                                       self.pending_events.lock().unwrap().push(events::Event::ChannelClosed { channel_id: chan.channel_id(),  reason: ClosureReason::DisconnectedPeer });
+                                                       self.issue_channel_close_events(chan, ClosureReason::DisconnectedPeer);
                                                        return false;
                                                } else {
                                                        no_channels_remain = false;
index 9fbbcfff39c9701306f0c06e0dcc47c0fdd7728b..92aaee100f6e87121354511c139baef16d99a2ba 100644 (file)
@@ -763,21 +763,29 @@ macro_rules! check_closed_broadcast {
        }}
 }
 
-/// Check that a channel's closing channel event has been issued
+/// Check that a channel's closing channel events has been issued
 #[macro_export]
 macro_rules! check_closed_event {
-       ($node: expr, $events: expr, $reason: expr) => {{
+       ($node: expr, $events: expr, $reason: expr) => {
+               check_closed_event!($node, $events, $reason, false);
+       };
+       ($node: expr, $events: expr, $reason: expr, $is_check_discard_funding: expr) => {{
                let events = $node.node.get_and_clear_pending_events();
                assert_eq!(events.len(), $events);
                let expected_reason = $reason;
+               let mut issues_discard_funding = false;
                for event in events {
                        match event {
                                Event::ChannelClosed { ref reason, .. } => {
                                        assert_eq!(*reason, expected_reason);
                                },
+                               Event::DiscardFunding { .. } => {
+                                       issues_discard_funding = true;
+                               }
                                _ => panic!("Unexpected event"),
                        }
                }
+               assert_eq!($is_check_discard_funding, issues_discard_funding);
        }}
 }
 
index 03b62ac185f44052246c40e341d0b29fc7918e0e..76d4eda13b0d3d24f1c139a92423ce3456fc7a38 100644 (file)
@@ -8632,7 +8632,7 @@ fn test_pre_lockin_no_chan_closed_update() {
        let channel_id = ::chain::transaction::OutPoint { txid: funding_created_msg.funding_txid, index: funding_created_msg.funding_output_index }.to_channel_id();
        nodes[0].node.handle_error(&nodes[1].node.get_our_node_id(), &msgs::ErrorMessage { channel_id, data: "Hi".to_owned() });
        assert!(nodes[0].chain_monitor.added_monitors.lock().unwrap().is_empty());
-       check_closed_event!(nodes[0], 1, ClosureReason::CounterpartyForceClosed { peer_msg: "Hi".to_string() });
+       check_closed_event!(nodes[0], 2, ClosureReason::CounterpartyForceClosed { peer_msg: "Hi".to_string() }, true);
 }
 
 #[test]
index 1319f7d2101cc1c5b861acc5c3c86e78dd72277b..7da4781ac7c76c0f57fd3665b2ebb99c2b7caeb1 100644 (file)
@@ -30,6 +30,7 @@ use io;
 use prelude::*;
 use core::time::Duration;
 use core::ops::Deref;
+use bitcoin::Transaction;
 
 /// Some information provided on receipt of payment depends on whether the payment received is a
 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
@@ -254,6 +255,14 @@ pub enum Event {
                channel_id: [u8; 32],
                /// The reason the channel was closed.
                reason: ClosureReason
+       },
+       /// Used to indicate to the user that they can abandon the funding transaction and recycle the
+       /// inputs for another purpose.
+       DiscardFunding {
+               /// The channel_id of the channel which has been closed.
+               channel_id: [u8; 32],
+               /// The full transaction received from the user
+               transaction: Transaction
        }
 }
 
@@ -340,6 +349,13 @@ impl Writeable for Event {
                                        (2, reason, required)
                                });
                        },
+                       &Event::DiscardFunding { ref channel_id, ref transaction } => {
+                               11u8.write(writer)?;
+                               write_tlv_fields!(writer, {
+                                       (0, channel_id, required),
+                                       (2, transaction, required)
+                               })
+                       },
                        // Note that, going forward, all new events must only write data inside of
                        // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
                        // data via `write_tlv_fields`.
@@ -471,6 +487,15 @@ impl MaybeReadable for Event {
                                if reason.is_none() { return Ok(None); }
                                Ok(Some(Event::ChannelClosed { channel_id, reason: reason.unwrap() }))
                        },
+                       11u8 => {
+                               let mut channel_id = [0; 32];
+                               let mut transaction = Transaction{ version: 2, lock_time: 0, input: Vec::new(), output: Vec::new() };
+                               read_tlv_fields!(reader, {
+                                       (0, channel_id, required),
+                                       (2, transaction, required),
+                               });
+                               Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
+                       },
                        // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
                        // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
                        // reads.