pub(super) pending_msg_events: Vec<MessageSendEvent>,
}
+/// Events which we process internally but cannot be procsesed immediately at the generation site
+/// for some reason. They are handled in timer_chan_freshness_every_min, so may be processed with
+/// quite some time lag.
+enum BackgroundEvent {
+ /// Handle a ChannelMonitorUpdate that closes a channel, broadcasting its current latest holder
+ /// commitment transaction.
+ ClosingMonitorUpdate((OutPoint, ChannelMonitorUpdate)),
+}
+
/// State we hold per-peer. In the future we should put channels in here, but for now we only hold
/// the latest Init features we heard from the peer.
struct PeerState {
per_peer_state: RwLock<HashMap<PublicKey, Mutex<PeerState>>>,
pending_events: Mutex<Vec<events::Event>>,
+ pending_background_events: Mutex<Vec<BackgroundEvent>>,
/// Used when we have to take a BIG lock to make sure everything is self-consistent.
/// Essentially just when we're serializing ourselves out.
/// Taken first everywhere where we are making changes before any other locks.
per_peer_state: RwLock::new(HashMap::new()),
pending_events: Mutex::new(Vec::new()),
+ pending_background_events: Mutex::new(Vec::new()),
total_consistency_lock: RwLock::new(()),
persistence_notifier: PersistenceNotifier::new(),
events.append(&mut new_events);
}
+ /// Free the background events, generally called from timer_chan_freshness_every_min.
+ ///
+ /// Exposed for testing to allow us to process events quickly without generating accidental
+ /// BroadcastChannelUpdate events in timer_chan_freshness_every_min.
+ ///
+ /// Expects the caller to have a total_consistency_lock read lock.
+ fn process_background_events(&self) {
+ let mut background_events = Vec::new();
+ mem::swap(&mut *self.pending_background_events.lock().unwrap(), &mut background_events);
+ for event in background_events.drain(..) {
+ match event {
+ BackgroundEvent::ClosingMonitorUpdate((funding_txo, update)) => {
+ // The channel has already been closed, so no use bothering to care about the
+ // monitor updating completing.
+ let _ = self.chain_monitor.update_channel(funding_txo, update);
+ },
+ }
+ }
+ }
+
+ #[cfg(any(test, feature = "_test_utils"))]
+ pub(crate) fn test_process_background_events(&self) {
+ self.process_background_events();
+ }
+
/// If a peer is disconnected we mark any channels with that peer as 'disabled'.
/// After some time, if channels are still disabled we need to broadcast a ChannelUpdate
/// to inform the network about the uselessness of these channels.
///
/// This method handles all the details, and must be called roughly once per minute.
+ ///
+ /// Note that in some rare cases this may generate a `chain::Watch::update_channel` call.
pub fn timer_chan_freshness_every_min(&self) {
let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+ self.process_background_events();
+
let mut channel_state_lock = self.channel_state.lock().unwrap();
let channel_state = &mut *channel_state_lock;
for (_, chan) in channel_state.by_id.iter_mut() {
//identify whether we sent it or not based on the (I presume) very different runtime
//between the branches here. We should make this async and move it into the forward HTLCs
//timer handling.
+
+ // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
+ // from block_connected which may run during initialization prior to the chain_monitor
+ // being fully configured. See the docs for `ChannelManagerReadArgs` for more.
match source {
HTLCSource::OutboundRoute { ref path, .. } => {
log_trace!(self.logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
self.finish_force_close_channel(failure);
}
}
+
+ /// Handle a list of channel failures during a block_connected or block_disconnected call,
+ /// pushing the channel monitor update (if any) to the background events queue and removing the
+ /// Channel object.
+ fn handle_init_event_channel_failures(&self, mut failed_channels: Vec<ShutdownResult>) {
+ for mut failure in failed_channels.drain(..) {
+ // Either a commitment transactions has been confirmed on-chain or
+ // Channel::block_disconnected detected that the funding transaction has been
+ // reorganized out of the main chain.
+ // We cannot broadcast our latest local state via monitor update (as
+ // Channel::force_shutdown tries to make us do) as we may still be in initialization,
+ // so we track the update internally and handle it when the user next calls
+ // timer_chan_freshness_every_min, guaranteeing we're running normally.
+ if let Some((funding_txo, update)) = failure.0.take() {
+ assert_eq!(update.updates.len(), 1);
+ if let ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } = update.updates[0] {
+ assert!(should_broadcast);
+ } else { unreachable!(); }
+ self.pending_background_events.lock().unwrap().push(BackgroundEvent::ClosingMonitorUpdate((funding_txo, update)));
+ }
+ self.finish_force_close_channel(failure);
+ }
+ }
}
impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> MessageSendEventsProvider for ChannelManager<Signer, M, T, K, F, L>
{
/// Updates channel state based on transactions seen in a connected block.
pub fn block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+ // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
+ // during initialization prior to the chain_monitor being fully configured in some cases.
+ // See the docs for `ChannelManagerReadArgs` for more.
let header_hash = header.block_hash();
log_trace!(self.logger, "Block {} at height {} connected", header_hash, height);
let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
if let Some(short_id) = channel.get_short_channel_id() {
short_to_id.remove(&short_id);
}
- // It looks like our counterparty went on-chain. We go ahead and
- // broadcast our latest local state as well here, just in case its
- // some kind of SPV attack, though we expect these to be dropped.
+ // It looks like our counterparty went on-chain. Close the channel.
failed_channels.push(channel.force_shutdown(true));
if let Ok(update) = self.get_channel_update(&channel) {
pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
!htlcs.is_empty() // Only retain this entry if htlcs has at least one entry.
});
}
- for failure in failed_channels.drain(..) {
- self.finish_force_close_channel(failure);
- }
+
+ self.handle_init_event_channel_failures(failed_channels);
for (source, payment_hash, reason) in timed_out_htlcs.drain(..) {
self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), source, &payment_hash, reason);
/// If necessary, the channel may be force-closed without letting the counterparty participate
/// in the shutdown.
pub fn block_disconnected(&self, header: &BlockHeader) {
+ // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
+ // during initialization prior to the chain_monitor being fully configured in some cases.
+ // See the docs for `ChannelManagerReadArgs` for more.
let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
let mut failed_channels = Vec::new();
{
}
});
}
- for failure in failed_channels.drain(..) {
- self.finish_force_close_channel(failure);
- }
+ self.handle_init_event_channel_failures(failed_channels);
self.latest_block_height.fetch_sub(1, Ordering::AcqRel);
*self.last_block_hash.try_lock().expect("block_(dis)connected must not be called in parallel") = header.block_hash();
}
event.write(writer)?;
}
+ let background_events = self.pending_background_events.lock().unwrap();
+ (background_events.len() as u64).write(writer)?;
+ for event in background_events.iter() {
+ match event {
+ BackgroundEvent::ClosingMonitorUpdate((funding_txo, monitor_update)) => {
+ 0u8.write(writer)?;
+ funding_txo.write(writer)?;
+ monitor_update.write(writer)?;
+ },
+ }
+ }
+
(self.last_node_announcement_serial.load(Ordering::Acquire) as u32).write(writer)?;
Ok(())
/// 3) Register all relevant ChannelMonitor outpoints with your chain watch mechanism using
/// ChannelMonitor::get_outputs_to_watch() and ChannelMonitor::get_funding_txo().
/// 4) Reconnect blocks on your ChannelMonitors.
-/// 5) Move the ChannelMonitors into your local chain::Watch.
-/// 6) Disconnect/connect blocks on the ChannelManager.
+/// 5) Disconnect/connect blocks on the ChannelManager.
+/// 6) Move the ChannelMonitors into your local chain::Watch.
+///
+/// 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 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
}
}
+ let background_event_count: u64 = Readable::read(reader)?;
+ let mut pending_background_events_read: Vec<BackgroundEvent> = Vec::with_capacity(cmp::min(background_event_count as usize, MAX_ALLOC_SIZE/mem::size_of::<BackgroundEvent>()));
+ for _ in 0..background_event_count {
+ match <u8 as Readable>::read(reader)? {
+ 0 => pending_background_events_read.push(BackgroundEvent::ClosingMonitorUpdate((Readable::read(reader)?, Readable::read(reader)?))),
+ _ => return Err(DecodeError::InvalidValue),
+ }
+ }
+
let last_node_announcement_serial: u32 = Readable::read(reader)?;
let mut secp_ctx = Secp256k1::new();
per_peer_state: RwLock::new(per_peer_state),
pending_events: Mutex::new(pending_events_read),
+ pending_background_events: Mutex::new(pending_background_events_read),
total_consistency_lock: RwLock::new(()),
persistence_notifier: PersistenceNotifier::new(),
projects / rust-lightning / commitdiff