Persist `ChannelMonitor`s after new blocks are connected

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 72f0bebdf1d3c1eb7cf9e505e75daaa286612884..1f3ad5541f1ba1d4697032d668c4f39765f29cb1 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -4090,7 +4090,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_update.source, &htlc_update.payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
                                        }
                                },
-                               MonitorEvent::CommitmentTxConfirmed(funding_outpoint) => {
+                               MonitorEvent::CommitmentTxConfirmed(funding_outpoint) |
+                               MonitorEvent::UpdateFailed(funding_outpoint) => {
                                        let mut channel_lock = self.channel_state.lock().unwrap();
                                        let channel_state = &mut *channel_lock;
                                        let by_id = &mut channel_state.by_id;
@@ -4106,7 +4107,12 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                msg: update
                                                        });
                                                }
-                                               self.issue_channel_close_events(&chan, ClosureReason::CommitmentTxConfirmed);
+                                               let reason = if let MonitorEvent::UpdateFailed(_) = monitor_event {
+                                                       ClosureReason::ProcessingError { err: "Failed to persist ChannelMonitor update during chain sync".to_string() }
+                                               } else {
+                                                       ClosureReason::CommitmentTxConfirmed
+                                               };
+                                               self.issue_channel_close_events(&chan, reason);
                                                pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                        node_id: chan.get_counterparty_node_id(),
                                                        action: msgs::ErrorAction::SendErrorMessage {
@@ -5440,20 +5446,25 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable f
 ///
 /// At a high-level, the process for deserializing a ChannelManager and resuming normal operation
 /// is:
-/// 1) Deserialize all stored ChannelMonitors.
-/// 2) Deserialize the ChannelManager by filling in this struct and calling:
-///    <(BlockHash, ChannelManager)>::read(reader, args)
-///    This may result in closing some Channels if the ChannelMonitor is newer than the stored
-///    ChannelManager state to ensure no loss of funds. Thus, transactions may be broadcasted.
-/// 3) If you are not fetching full blocks, register all relevant ChannelMonitor outpoints the same
-///    way you would handle a `chain::Filter` call using ChannelMonitor::get_outputs_to_watch() and
-///    ChannelMonitor::get_funding_txo().
-/// 4) Reconnect blocks on your ChannelMonitors.
-/// 5) Disconnect/connect blocks on the ChannelManager.
-/// 6) Move the ChannelMonitors into your local chain::Watch.
+/// 1) Deserialize all stored [`ChannelMonitor`]s.
+/// 2) Deserialize the [`ChannelManager`] by filling in this struct and calling:
+///    `<(BlockHash, ChannelManager)>::read(reader, args)`
+///    This may result in closing some channels if the [`ChannelMonitor`] is newer than the stored
+///    [`ChannelManager`] state to ensure no loss of funds. Thus, transactions may be broadcasted.
+/// 3) If you are not fetching full blocks, register all relevant [`ChannelMonitor`] outpoints the
+///    same way you would handle a [`chain::Filter`] call using
+///    [`ChannelMonitor::get_outputs_to_watch`] and [`ChannelMonitor::get_funding_txo`].
+/// 4) Reconnect blocks on your [`ChannelMonitor`]s.
+/// 5) Disconnect/connect blocks on the [`ChannelManager`].
+/// 6) Re-persist the [`ChannelMonitor`]s to ensure the latest state is on disk.
+///    Note that if you're using a [`ChainMonitor`] for your [`chain::Watch`] implementation, you
+///    will likely accomplish this as a side-effect of calling [`chain::Watch::watch_channel`] in
+///    the next step.
+/// 7) Move the [`ChannelMonitor`]s into your local [`chain::Watch`]. If you're using a
+///    [`ChainMonitor`], this is done by calling [`chain::Watch::watch_channel`].
 ///
-/// Note that the ordering of #4-6 is not of importance, however all three must occur before you
-/// call any other methods on the newly-deserialized ChannelManager.
+/// Note that the ordering of #4-7 is not of importance, however all four must occur before you
+/// call any other methods on the newly-deserialized [`ChannelManager`].
 ///
 /// Note that because some channels may be closed during deserialization, it is critical that you
 /// always deserialize only the latest version of a ChannelManager and ChannelMonitors available to
@@ -5461,6 +5472,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable f
 /// broadcast), and then later deserialize a newer version of the same ChannelManager (which will
 /// not force-close the same channels but consider them live), you may end up revoking a state for
 /// which you've already broadcasted the transaction.
+///
+/// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
 pub struct ChannelManagerReadArgs<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
        where M::Target: chain::Watch<Signer>,
         T::Target: BroadcasterInterface,