1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Logic to connect off-chain channel management with on-chain transaction monitoring.
12 //! [`ChainMonitor`] is an implementation of [`chain::Watch`] used both to process blocks and to
13 //! update [`ChannelMonitor`]s accordingly. If any on-chain events need further processing, it will
14 //! make those available as [`MonitorEvent`]s to be consumed.
16 //! [`ChainMonitor`] is parameterized by an optional chain source, which must implement the
17 //! [`chain::Filter`] trait. This provides a mechanism to signal new relevant outputs back to light
18 //! clients, such that transactions spending those outputs are included in block data.
20 //! [`ChainMonitor`] may be used directly to monitor channels locally or as a part of a distributed
21 //! setup to monitor channels remotely. In the latter case, a custom [`chain::Watch`] implementation
22 //! would be responsible for routing each update to a remote server and for retrieving monitor
23 //! events. The remote server would make use of [`ChainMonitor`] for block processing and for
24 //! servicing [`ChannelMonitor`] updates from the client.
26 use bitcoin::blockdata::block::BlockHeader;
27 use bitcoin::hash_types::{Txid, BlockHash};
30 use crate::chain::{ChannelMonitorUpdateStatus, Filter, WatchedOutput};
31 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
32 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, Balance, MonitorEvent, TransactionOutputs, LATENCY_GRACE_PERIOD_BLOCKS};
33 use crate::chain::transaction::{OutPoint, TransactionData};
34 use crate::sign::WriteableEcdsaChannelSigner;
36 use crate::events::{Event, EventHandler};
37 use crate::util::atomic_counter::AtomicCounter;
38 use crate::util::logger::Logger;
39 use crate::util::errors::APIError;
40 use crate::util::wakers::{Future, Notifier};
41 use crate::ln::channelmanager::ChannelDetails;
43 use crate::prelude::*;
44 use crate::sync::{RwLock, RwLockReadGuard, Mutex, MutexGuard};
45 use core::iter::FromIterator;
47 use core::sync::atomic::{AtomicUsize, Ordering};
48 use bitcoin::secp256k1::PublicKey;
50 #[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
51 /// A specific update's ID stored in a `MonitorUpdateId`, separated out to make the contents
54 /// An update that was generated by the `ChannelManager` (via our `chain::Watch`
55 /// implementation). This corresponds to an actual [`ChannelMonitorUpdate::update_id`] field
56 /// and [`ChannelMonitor::get_latest_update_id`].
58 /// An update that was generated during blockchain processing. The ID here is specific to the
59 /// generating [`ChainMonitor`] and does *not* correspond to any on-disk IDs.
63 /// An opaque identifier describing a specific [`Persist`] method call.
64 #[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
65 pub struct MonitorUpdateId {
66 contents: UpdateOrigin,
69 impl MonitorUpdateId {
70 pub(crate) fn from_monitor_update(update: &ChannelMonitorUpdate) -> Self {
71 Self { contents: UpdateOrigin::OffChain(update.update_id) }
73 pub(crate) fn from_new_monitor<ChannelSigner: WriteableEcdsaChannelSigner>(monitor: &ChannelMonitor<ChannelSigner>) -> Self {
74 Self { contents: UpdateOrigin::OffChain(monitor.get_latest_update_id()) }
78 /// `Persist` defines behavior for persisting channel monitors: this could mean
79 /// writing once to disk, and/or uploading to one or more backup services.
81 /// Persistence can happen in one of two ways - synchronously completing before the trait method
82 /// calls return or asynchronously in the background.
84 /// # For those implementing synchronous persistence
86 /// * If persistence completes fully (including any relevant `fsync()` calls), the implementation
87 /// should return [`ChannelMonitorUpdateStatus::Completed`], indicating normal channel operation
90 /// * If persistence fails for some reason, implementations should consider returning
91 /// [`ChannelMonitorUpdateStatus::InProgress`] and retry all pending persistence operations in
92 /// the background with [`ChainMonitor::list_pending_monitor_updates`] and
93 /// [`ChainMonitor::get_monitor`].
95 /// Once a full [`ChannelMonitor`] has been persisted, all pending updates for that channel can
96 /// be marked as complete via [`ChainMonitor::channel_monitor_updated`].
98 /// If at some point no further progress can be made towards persisting the pending updates, the
99 /// node should simply shut down.
101 /// * If the persistence has failed and cannot be retried further (e.g. because of an outage),
102 /// [`ChannelMonitorUpdateStatus::UnrecoverableError`] can be used, though this will result in
103 /// an immediate panic and future operations in LDK generally failing.
105 /// # For those implementing asynchronous persistence
107 /// All calls should generally spawn a background task and immediately return
108 /// [`ChannelMonitorUpdateStatus::InProgress`]. Once the update completes,
109 /// [`ChainMonitor::channel_monitor_updated`] should be called with the corresponding
110 /// [`MonitorUpdateId`].
112 /// Note that unlike the direct [`chain::Watch`] interface,
113 /// [`ChainMonitor::channel_monitor_updated`] must be called once for *each* update which occurs.
115 /// If at some point no further progress can be made towards persisting a pending update, the node
116 /// should simply shut down. Until then, the background task should either loop indefinitely, or
117 /// persistence should be regularly retried with [`ChainMonitor::list_pending_monitor_updates`]
118 /// and [`ChainMonitor::get_monitor`] (note that if a full monitor is persisted all pending
119 /// monitor updates may be marked completed).
121 /// # Using remote watchtowers
123 /// Watchtowers may be updated as a part of an implementation of this trait, utilizing the async
124 /// update process described above while the watchtower is being updated. The following methods are
125 /// provided for bulding transactions for a watchtower:
126 /// [`ChannelMonitor::initial_counterparty_commitment_tx`],
127 /// [`ChannelMonitor::counterparty_commitment_txs_from_update`],
128 /// [`ChannelMonitor::sign_to_local_justice_tx`], [`TrustedCommitmentTransaction::revokeable_output_index`],
129 /// [`TrustedCommitmentTransaction::build_to_local_justice_tx`].
131 /// [`TrustedCommitmentTransaction::revokeable_output_index`]: crate::ln::chan_utils::TrustedCommitmentTransaction::revokeable_output_index
132 /// [`TrustedCommitmentTransaction::build_to_local_justice_tx`]: crate::ln::chan_utils::TrustedCommitmentTransaction::build_to_local_justice_tx
133 pub trait Persist<ChannelSigner: WriteableEcdsaChannelSigner> {
134 /// Persist a new channel's data in response to a [`chain::Watch::watch_channel`] call. This is
135 /// called by [`ChannelManager`] for new channels, or may be called directly, e.g. on startup.
137 /// The data can be stored any way you want, but the identifier provided by LDK is the
138 /// channel's outpoint (and it is up to you to maintain a correct mapping between the outpoint
139 /// and the stored channel data). Note that you **must** persist every new monitor to disk.
141 /// The `update_id` is used to identify this call to [`ChainMonitor::channel_monitor_updated`],
142 /// if you return [`ChannelMonitorUpdateStatus::InProgress`].
144 /// See [`Writeable::write`] on [`ChannelMonitor`] for writing out a `ChannelMonitor`
145 /// and [`ChannelMonitorUpdateStatus`] for requirements when returning errors.
147 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
148 /// [`Writeable::write`]: crate::util::ser::Writeable::write
149 fn persist_new_channel(&self, channel_id: OutPoint, data: &ChannelMonitor<ChannelSigner>, update_id: MonitorUpdateId) -> ChannelMonitorUpdateStatus;
151 /// Update one channel's data. The provided [`ChannelMonitor`] has already applied the given
154 /// Note that on every update, you **must** persist either the [`ChannelMonitorUpdate`] or the
155 /// updated monitor itself to disk/backups. See the [`Persist`] trait documentation for more
158 /// During blockchain synchronization operations, this may be called with no
159 /// [`ChannelMonitorUpdate`], in which case the full [`ChannelMonitor`] needs to be persisted.
160 /// Note that after the full [`ChannelMonitor`] is persisted any previous
161 /// [`ChannelMonitorUpdate`]s which were persisted should be discarded - they can no longer be
162 /// applied to the persisted [`ChannelMonitor`] as they were already applied.
164 /// If an implementer chooses to persist the updates only, they need to make
165 /// sure that all the updates are applied to the `ChannelMonitors` *before*
166 /// the set of channel monitors is given to the `ChannelManager`
167 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
168 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
169 /// persisted, then there is no need to persist individual updates.
171 /// Note that there could be a performance tradeoff between persisting complete
172 /// channel monitors on every update vs. persisting only updates and applying
173 /// them in batches. The size of each monitor grows `O(number of state updates)`
174 /// whereas updates are small and `O(1)`.
176 /// The `update_id` is used to identify this call to [`ChainMonitor::channel_monitor_updated`],
177 /// if you return [`ChannelMonitorUpdateStatus::InProgress`].
179 /// See [`Writeable::write`] on [`ChannelMonitor`] for writing out a `ChannelMonitor`,
180 /// [`Writeable::write`] on [`ChannelMonitorUpdate`] for writing out an update, and
181 /// [`ChannelMonitorUpdateStatus`] for requirements when returning errors.
183 /// [`Writeable::write`]: crate::util::ser::Writeable::write
184 fn update_persisted_channel(&self, channel_id: OutPoint, update: Option<&ChannelMonitorUpdate>, data: &ChannelMonitor<ChannelSigner>, update_id: MonitorUpdateId) -> ChannelMonitorUpdateStatus;
187 struct MonitorHolder<ChannelSigner: WriteableEcdsaChannelSigner> {
188 monitor: ChannelMonitor<ChannelSigner>,
189 /// The full set of pending monitor updates for this Channel.
191 /// Note that this lock must be held during updates to prevent a race where we call
192 /// update_persisted_channel, the user returns a
193 /// [`ChannelMonitorUpdateStatus::InProgress`], and then calls channel_monitor_updated
194 /// immediately, racing our insertion of the pending update into the contained Vec.
196 /// Beyond the synchronization of updates themselves, we cannot handle user events until after
197 /// any chain updates have been stored on disk. Thus, we scan this list when returning updates
198 /// to the ChannelManager, refusing to return any updates for a ChannelMonitor which is still
199 /// being persisted fully to disk after a chain update.
201 /// This avoids the possibility of handling, e.g. an on-chain claim, generating a claim monitor
202 /// event, resulting in the relevant ChannelManager generating a PaymentSent event and dropping
203 /// the pending payment entry, and then reloading before the monitor is persisted, resulting in
204 /// the ChannelManager re-adding the same payment entry, before the same block is replayed,
205 /// resulting in a duplicate PaymentSent event.
206 pending_monitor_updates: Mutex<Vec<MonitorUpdateId>>,
207 /// The last block height at which no [`UpdateOrigin::ChainSync`] monitor updates were present
208 /// in `pending_monitor_updates`.
209 /// If it's been more than [`LATENCY_GRACE_PERIOD_BLOCKS`] since we started waiting on a chain
210 /// sync event, we let monitor events return to `ChannelManager` because we cannot hold them up
211 /// forever or we'll end up with HTLC preimages waiting to feed back into an upstream channel
212 /// forever, risking funds loss.
213 last_chain_persist_height: AtomicUsize,
216 impl<ChannelSigner: WriteableEcdsaChannelSigner> MonitorHolder<ChannelSigner> {
217 fn has_pending_offchain_updates(&self, pending_monitor_updates_lock: &MutexGuard<Vec<MonitorUpdateId>>) -> bool {
218 pending_monitor_updates_lock.iter().any(|update_id|
219 if let UpdateOrigin::OffChain(_) = update_id.contents { true } else { false })
221 fn has_pending_chainsync_updates(&self, pending_monitor_updates_lock: &MutexGuard<Vec<MonitorUpdateId>>) -> bool {
222 pending_monitor_updates_lock.iter().any(|update_id|
223 if let UpdateOrigin::ChainSync(_) = update_id.contents { true } else { false })
227 /// A read-only reference to a current ChannelMonitor.
229 /// Note that this holds a mutex in [`ChainMonitor`] and may block other events until it is
231 pub struct LockedChannelMonitor<'a, ChannelSigner: WriteableEcdsaChannelSigner> {
232 lock: RwLockReadGuard<'a, HashMap<OutPoint, MonitorHolder<ChannelSigner>>>,
233 funding_txo: OutPoint,
236 impl<ChannelSigner: WriteableEcdsaChannelSigner> Deref for LockedChannelMonitor<'_, ChannelSigner> {
237 type Target = ChannelMonitor<ChannelSigner>;
238 fn deref(&self) -> &ChannelMonitor<ChannelSigner> {
239 &self.lock.get(&self.funding_txo).expect("Checked at construction").monitor
243 /// An implementation of [`chain::Watch`] for monitoring channels.
245 /// Connected and disconnected blocks must be provided to `ChainMonitor` as documented by
246 /// [`chain::Watch`]. May be used in conjunction with [`ChannelManager`] to monitor channels locally
247 /// or used independently to monitor channels remotely. See the [module-level documentation] for
250 /// Note that `ChainMonitor` should regularly trigger rebroadcasts/fee bumps of pending claims from
251 /// a force-closed channel. This is crucial in preventing certain classes of pinning attacks,
252 /// detecting substantial mempool feerate changes between blocks, and ensuring reliability if
253 /// broadcasting fails. We recommend invoking this every 30 seconds, or lower if running in an
254 /// environment with spotty connections, like on mobile.
256 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
257 /// [module-level documentation]: crate::chain::chainmonitor
258 /// [`rebroadcast_pending_claims`]: Self::rebroadcast_pending_claims
259 pub struct ChainMonitor<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
260 where C::Target: chain::Filter,
261 T::Target: BroadcasterInterface,
262 F::Target: FeeEstimator,
264 P::Target: Persist<ChannelSigner>,
266 monitors: RwLock<HashMap<OutPoint, MonitorHolder<ChannelSigner>>>,
267 /// When we generate a [`MonitorUpdateId`] for a chain-event monitor persistence, we need a
268 /// unique ID, which we calculate by simply getting the next value from this counter. Note that
269 /// the ID is never persisted so it's ok that they reset on restart.
270 sync_persistence_id: AtomicCounter,
271 chain_source: Option<C>,
276 /// "User-provided" (ie persistence-completion/-failed) [`MonitorEvent`]s. These came directly
277 /// from the user and not from a [`ChannelMonitor`].
278 pending_monitor_events: Mutex<Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>>,
279 /// The best block height seen, used as a proxy for the passage of time.
280 highest_chain_height: AtomicUsize,
282 event_notifier: Notifier,
285 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> ChainMonitor<ChannelSigner, C, T, F, L, P>
286 where C::Target: chain::Filter,
287 T::Target: BroadcasterInterface,
288 F::Target: FeeEstimator,
290 P::Target: Persist<ChannelSigner>,
292 /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
293 /// of a channel and reacting accordingly based on transactions in the given chain data. See
294 /// [`ChannelMonitor::block_connected`] for details. Any HTLCs that were resolved on chain will
295 /// be returned by [`chain::Watch::release_pending_monitor_events`].
297 /// Calls back to [`chain::Filter`] if any monitor indicated new outputs to watch. Subsequent
298 /// calls must not exclude any transactions matching the new outputs nor any in-block
299 /// descendants of such transactions. It is not necessary to re-fetch the block to obtain
300 /// updated `txdata`.
302 /// Calls which represent a new blockchain tip height should set `best_height`.
303 fn process_chain_data<FN>(&self, header: &BlockHeader, best_height: Option<u32>, txdata: &TransactionData, process: FN)
305 FN: Fn(&ChannelMonitor<ChannelSigner>, &TransactionData) -> Vec<TransactionOutputs>
307 let err_str = "ChannelMonitor[Update] persistence failed unrecoverably. This indicates we cannot continue normal operation and must shut down.";
308 let funding_outpoints: HashSet<OutPoint> = HashSet::from_iter(self.monitors.read().unwrap().keys().cloned());
309 for funding_outpoint in funding_outpoints.iter() {
310 let monitor_lock = self.monitors.read().unwrap();
311 if let Some(monitor_state) = monitor_lock.get(funding_outpoint) {
312 if self.update_monitor_with_chain_data(header, best_height, txdata, &process, funding_outpoint, &monitor_state).is_err() {
313 // Take the monitors lock for writing so that we poison it and any future
314 // operations going forward fail immediately.
315 core::mem::drop(monitor_state);
316 core::mem::drop(monitor_lock);
317 let _poison = self.monitors.write().unwrap();
318 log_error!(self.logger, "{}", err_str);
319 panic!("{}", err_str);
324 // do some followup cleanup if any funding outpoints were added in between iterations
325 let monitor_states = self.monitors.write().unwrap();
326 for (funding_outpoint, monitor_state) in monitor_states.iter() {
327 if !funding_outpoints.contains(funding_outpoint) {
328 if self.update_monitor_with_chain_data(header, best_height, txdata, &process, funding_outpoint, &monitor_state).is_err() {
329 log_error!(self.logger, "{}", err_str);
330 panic!("{}", err_str);
335 if let Some(height) = best_height {
336 // If the best block height is being updated, update highest_chain_height under the
337 // monitors write lock.
338 let old_height = self.highest_chain_height.load(Ordering::Acquire);
339 let new_height = height as usize;
340 if new_height > old_height {
341 self.highest_chain_height.store(new_height, Ordering::Release);
346 fn update_monitor_with_chain_data<FN>(
347 &self, header: &BlockHeader, best_height: Option<u32>, txdata: &TransactionData,
348 process: FN, funding_outpoint: &OutPoint, monitor_state: &MonitorHolder<ChannelSigner>
349 ) -> Result<(), ()> where FN: Fn(&ChannelMonitor<ChannelSigner>, &TransactionData) -> Vec<TransactionOutputs> {
350 let monitor = &monitor_state.monitor;
353 txn_outputs = process(monitor, txdata);
354 let update_id = MonitorUpdateId {
355 contents: UpdateOrigin::ChainSync(self.sync_persistence_id.get_increment()),
357 let mut pending_monitor_updates = monitor_state.pending_monitor_updates.lock().unwrap();
358 if let Some(height) = best_height {
359 if !monitor_state.has_pending_chainsync_updates(&pending_monitor_updates) {
360 // If there are not ChainSync persists awaiting completion, go ahead and
361 // set last_chain_persist_height here - we wouldn't want the first
362 // InProgress to always immediately be considered "overly delayed".
363 monitor_state.last_chain_persist_height.store(height as usize, Ordering::Release);
367 log_trace!(self.logger, "Syncing Channel Monitor for channel {}", log_funding_info!(monitor));
368 match self.persister.update_persisted_channel(*funding_outpoint, None, monitor, update_id) {
369 ChannelMonitorUpdateStatus::Completed =>
370 log_trace!(self.logger, "Finished syncing Channel Monitor for channel {}", log_funding_info!(monitor)),
371 ChannelMonitorUpdateStatus::InProgress => {
372 log_debug!(self.logger, "Channel Monitor sync for channel {} in progress, holding events until completion!", log_funding_info!(monitor));
373 pending_monitor_updates.push(update_id);
375 ChannelMonitorUpdateStatus::UnrecoverableError => {
381 // Register any new outputs with the chain source for filtering, storing any dependent
382 // transactions from within the block that previously had not been included in txdata.
383 if let Some(ref chain_source) = self.chain_source {
384 let block_hash = header.block_hash();
385 for (txid, mut outputs) in txn_outputs.drain(..) {
386 for (idx, output) in outputs.drain(..) {
387 // Register any new outputs with the chain source for filtering
388 let output = WatchedOutput {
389 block_hash: Some(block_hash),
390 outpoint: OutPoint { txid, index: idx as u16 },
391 script_pubkey: output.script_pubkey,
393 chain_source.register_output(output)
400 /// Creates a new `ChainMonitor` used to watch on-chain activity pertaining to channels.
402 /// When an optional chain source implementing [`chain::Filter`] is provided, the chain monitor
403 /// will call back to it indicating transactions and outputs of interest. This allows clients to
404 /// pre-filter blocks or only fetch blocks matching a compact filter. Otherwise, clients may
405 /// always need to fetch full blocks absent another means for determining which blocks contain
406 /// transactions relevant to the watched channels.
407 pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F, persister: P) -> Self {
409 monitors: RwLock::new(HashMap::new()),
410 sync_persistence_id: AtomicCounter::new(),
414 fee_estimator: feeest,
416 pending_monitor_events: Mutex::new(Vec::new()),
417 highest_chain_height: AtomicUsize::new(0),
418 event_notifier: Notifier::new(),
422 /// Gets the balances in the contained [`ChannelMonitor`]s which are claimable on-chain or
423 /// claims which are awaiting confirmation.
425 /// Includes the balances from each [`ChannelMonitor`] *except* those included in
426 /// `ignored_channels`.
428 /// See [`ChannelMonitor::get_claimable_balances`] for more details on the exact criteria for
429 /// inclusion in the return value.
430 pub fn get_claimable_balances(&self, ignored_channels: &[&ChannelDetails]) -> Vec<Balance> {
431 let mut ret = Vec::new();
432 let monitor_states = self.monitors.read().unwrap();
433 for (_, monitor_state) in monitor_states.iter().filter(|(funding_outpoint, _)| {
434 for chan in ignored_channels {
435 if chan.funding_txo.as_ref() == Some(funding_outpoint) {
441 ret.append(&mut monitor_state.monitor.get_claimable_balances());
446 /// Gets the [`LockedChannelMonitor`] for a given funding outpoint, returning an `Err` if no
447 /// such [`ChannelMonitor`] is currently being monitored for.
449 /// Note that the result holds a mutex over our monitor set, and should not be held
451 pub fn get_monitor(&self, funding_txo: OutPoint) -> Result<LockedChannelMonitor<'_, ChannelSigner>, ()> {
452 let lock = self.monitors.read().unwrap();
453 if lock.get(&funding_txo).is_some() {
454 Ok(LockedChannelMonitor { lock, funding_txo })
460 /// Lists the funding outpoint of each [`ChannelMonitor`] being monitored.
462 /// Note that [`ChannelMonitor`]s are not removed when a channel is closed as they are always
463 /// monitoring for on-chain state resolutions.
464 pub fn list_monitors(&self) -> Vec<OutPoint> {
465 self.monitors.read().unwrap().keys().map(|outpoint| *outpoint).collect()
468 #[cfg(not(c_bindings))]
469 /// Lists the pending updates for each [`ChannelMonitor`] (by `OutPoint` being monitored).
470 pub fn list_pending_monitor_updates(&self) -> HashMap<OutPoint, Vec<MonitorUpdateId>> {
471 self.monitors.read().unwrap().iter().map(|(outpoint, holder)| {
472 (*outpoint, holder.pending_monitor_updates.lock().unwrap().clone())
477 /// Lists the pending updates for each [`ChannelMonitor`] (by `OutPoint` being monitored).
478 pub fn list_pending_monitor_updates(&self) -> Vec<(OutPoint, Vec<MonitorUpdateId>)> {
479 self.monitors.read().unwrap().iter().map(|(outpoint, holder)| {
480 (*outpoint, holder.pending_monitor_updates.lock().unwrap().clone())
486 pub fn remove_monitor(&self, funding_txo: &OutPoint) -> ChannelMonitor<ChannelSigner> {
487 self.monitors.write().unwrap().remove(funding_txo).unwrap().monitor
490 /// Indicates the persistence of a [`ChannelMonitor`] has completed after
491 /// [`ChannelMonitorUpdateStatus::InProgress`] was returned from an update operation.
493 /// Thus, the anticipated use is, at a high level:
494 /// 1) This [`ChainMonitor`] calls [`Persist::update_persisted_channel`] which stores the
495 /// update to disk and begins updating any remote (e.g. watchtower/backup) copies,
496 /// returning [`ChannelMonitorUpdateStatus::InProgress`],
497 /// 2) once all remote copies are updated, you call this function with the
498 /// `completed_update_id` that completed, and once all pending updates have completed the
499 /// channel will be re-enabled.
500 // Note that we re-enable only after `UpdateOrigin::OffChain` updates complete, we don't
501 // care about `UpdateOrigin::ChainSync` updates for the channel state being updated. We
502 // only care about `UpdateOrigin::ChainSync` for returning `MonitorEvent`s.
504 /// Returns an [`APIError::APIMisuseError`] if `funding_txo` does not match any currently
505 /// registered [`ChannelMonitor`]s.
506 pub fn channel_monitor_updated(&self, funding_txo: OutPoint, completed_update_id: MonitorUpdateId) -> Result<(), APIError> {
507 let monitors = self.monitors.read().unwrap();
508 let monitor_data = if let Some(mon) = monitors.get(&funding_txo) { mon } else {
509 return Err(APIError::APIMisuseError { err: format!("No ChannelMonitor matching funding outpoint {:?} found", funding_txo) });
511 let mut pending_monitor_updates = monitor_data.pending_monitor_updates.lock().unwrap();
512 pending_monitor_updates.retain(|update_id| *update_id != completed_update_id);
514 match completed_update_id {
515 MonitorUpdateId { contents: UpdateOrigin::OffChain(_) } => {
516 // Note that we only check for `UpdateOrigin::OffChain` failures here - if
517 // we're being told that a `UpdateOrigin::OffChain` monitor update completed,
518 // we only care about ensuring we don't tell the `ChannelManager` to restore
519 // the channel to normal operation until all `UpdateOrigin::OffChain` updates
521 // If there's some `UpdateOrigin::ChainSync` update still pending that's okay
522 // - we can still update our channel state, just as long as we don't return
523 // `MonitorEvent`s from the monitor back to the `ChannelManager` until they
525 let monitor_is_pending_updates = monitor_data.has_pending_offchain_updates(&pending_monitor_updates);
526 if monitor_is_pending_updates {
527 // If there are still monitor updates pending, we cannot yet construct a
531 self.pending_monitor_events.lock().unwrap().push((funding_txo, vec![MonitorEvent::Completed {
533 monitor_update_id: monitor_data.monitor.get_latest_update_id(),
534 }], monitor_data.monitor.get_counterparty_node_id()));
536 MonitorUpdateId { contents: UpdateOrigin::ChainSync(_) } => {
537 if !monitor_data.has_pending_chainsync_updates(&pending_monitor_updates) {
538 monitor_data.last_chain_persist_height.store(self.highest_chain_height.load(Ordering::Acquire), Ordering::Release);
539 // The next time release_pending_monitor_events is called, any events for this
540 // ChannelMonitor will be returned.
544 self.event_notifier.notify();
548 /// This wrapper avoids having to update some of our tests for now as they assume the direct
549 /// chain::Watch API wherein we mark a monitor fully-updated by just calling
550 /// channel_monitor_updated once with the highest ID.
551 #[cfg(any(test, fuzzing))]
552 pub fn force_channel_monitor_updated(&self, funding_txo: OutPoint, monitor_update_id: u64) {
553 let monitors = self.monitors.read().unwrap();
554 let counterparty_node_id = monitors.get(&funding_txo).and_then(|m| m.monitor.get_counterparty_node_id());
555 self.pending_monitor_events.lock().unwrap().push((funding_txo, vec![MonitorEvent::Completed {
558 }], counterparty_node_id));
559 self.event_notifier.notify();
562 #[cfg(any(test, feature = "_test_utils"))]
563 pub fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
564 use crate::events::EventsProvider;
565 let events = core::cell::RefCell::new(Vec::new());
566 let event_handler = |event: events::Event| events.borrow_mut().push(event);
567 self.process_pending_events(&event_handler);
571 /// Processes any events asynchronously in the order they were generated since the last call
572 /// using the given event handler.
574 /// See the trait-level documentation of [`EventsProvider`] for requirements.
576 /// [`EventsProvider`]: crate::events::EventsProvider
577 pub async fn process_pending_events_async<Future: core::future::Future, H: Fn(Event) -> Future>(
580 // Sadly we can't hold the monitors read lock through an async call. Thus we have to do a
581 // crazy dance to process a monitor's events then only remove them once we've done so.
582 let mons_to_process = self.monitors.read().unwrap().keys().cloned().collect::<Vec<_>>();
583 for funding_txo in mons_to_process {
585 super::channelmonitor::process_events_body!(
586 self.monitors.read().unwrap().get(&funding_txo).map(|m| &m.monitor), ev, handler(ev).await);
590 /// Gets a [`Future`] that completes when an event is available either via
591 /// [`chain::Watch::release_pending_monitor_events`] or
592 /// [`EventsProvider::process_pending_events`].
594 /// Note that callbacks registered on the [`Future`] MUST NOT call back into this
595 /// [`ChainMonitor`] and should instead register actions to be taken later.
597 /// [`EventsProvider::process_pending_events`]: crate::events::EventsProvider::process_pending_events
598 pub fn get_update_future(&self) -> Future {
599 self.event_notifier.get_future()
602 /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
603 /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
604 /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
605 /// invoking this every 30 seconds, or lower if running in an environment with spotty
606 /// connections, like on mobile.
607 pub fn rebroadcast_pending_claims(&self) {
608 let monitors = self.monitors.read().unwrap();
609 for (_, monitor_holder) in &*monitors {
610 monitor_holder.monitor.rebroadcast_pending_claims(
611 &*self.broadcaster, &*self.fee_estimator, &*self.logger
617 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
618 chain::Listen for ChainMonitor<ChannelSigner, C, T, F, L, P>
620 C::Target: chain::Filter,
621 T::Target: BroadcasterInterface,
622 F::Target: FeeEstimator,
624 P::Target: Persist<ChannelSigner>,
626 fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
627 log_debug!(self.logger, "New best block {} at height {} provided via block_connected", header.block_hash(), height);
628 self.process_chain_data(header, Some(height), &txdata, |monitor, txdata| {
629 monitor.block_connected(
630 header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger)
634 fn block_disconnected(&self, header: &BlockHeader, height: u32) {
635 let monitor_states = self.monitors.read().unwrap();
636 log_debug!(self.logger, "Latest block {} at height {} removed via block_disconnected", header.block_hash(), height);
637 for monitor_state in monitor_states.values() {
638 monitor_state.monitor.block_disconnected(
639 header, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
644 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>
645 chain::Confirm for ChainMonitor<ChannelSigner, C, T, F, L, P>
647 C::Target: chain::Filter,
648 T::Target: BroadcasterInterface,
649 F::Target: FeeEstimator,
651 P::Target: Persist<ChannelSigner>,
653 fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
654 log_debug!(self.logger, "{} provided transactions confirmed at height {} in block {}", txdata.len(), height, header.block_hash());
655 self.process_chain_data(header, None, txdata, |monitor, txdata| {
656 monitor.transactions_confirmed(
657 header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger)
661 fn transaction_unconfirmed(&self, txid: &Txid) {
662 log_debug!(self.logger, "Transaction {} reorganized out of chain", txid);
663 let monitor_states = self.monitors.read().unwrap();
664 for monitor_state in monitor_states.values() {
665 monitor_state.monitor.transaction_unconfirmed(txid, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
669 fn best_block_updated(&self, header: &BlockHeader, height: u32) {
670 log_debug!(self.logger, "New best block {} at height {} provided via best_block_updated", header.block_hash(), height);
671 self.process_chain_data(header, Some(height), &[], |monitor, txdata| {
672 // While in practice there shouldn't be any recursive calls when given empty txdata,
673 // it's still possible if a chain::Filter implementation returns a transaction.
674 debug_assert!(txdata.is_empty());
675 monitor.best_block_updated(
676 header, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger)
680 fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
681 let mut txids = Vec::new();
682 let monitor_states = self.monitors.read().unwrap();
683 for monitor_state in monitor_states.values() {
684 txids.append(&mut monitor_state.monitor.get_relevant_txids());
687 txids.sort_unstable();
693 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref , T: Deref , F: Deref , L: Deref , P: Deref >
694 chain::Watch<ChannelSigner> for ChainMonitor<ChannelSigner, C, T, F, L, P>
695 where C::Target: chain::Filter,
696 T::Target: BroadcasterInterface,
697 F::Target: FeeEstimator,
699 P::Target: Persist<ChannelSigner>,
701 fn watch_channel(&self, funding_outpoint: OutPoint, monitor: ChannelMonitor<ChannelSigner>) -> Result<ChannelMonitorUpdateStatus, ()> {
702 let mut monitors = self.monitors.write().unwrap();
703 let entry = match monitors.entry(funding_outpoint) {
704 hash_map::Entry::Occupied(_) => {
705 log_error!(self.logger, "Failed to add new channel data: channel monitor for given outpoint is already present");
708 hash_map::Entry::Vacant(e) => e,
710 log_trace!(self.logger, "Got new ChannelMonitor for channel {}", log_funding_info!(monitor));
711 let update_id = MonitorUpdateId::from_new_monitor(&monitor);
712 let mut pending_monitor_updates = Vec::new();
713 let persist_res = self.persister.persist_new_channel(funding_outpoint, &monitor, update_id);
715 ChannelMonitorUpdateStatus::InProgress => {
716 log_info!(self.logger, "Persistence of new ChannelMonitor for channel {} in progress", log_funding_info!(monitor));
717 pending_monitor_updates.push(update_id);
719 ChannelMonitorUpdateStatus::Completed => {
720 log_info!(self.logger, "Persistence of new ChannelMonitor for channel {} completed", log_funding_info!(monitor));
722 ChannelMonitorUpdateStatus::UnrecoverableError => {
723 let err_str = "ChannelMonitor[Update] persistence failed unrecoverably. This indicates we cannot continue normal operation and must shut down.";
724 log_error!(self.logger, "{}", err_str);
725 panic!("{}", err_str);
728 if let Some(ref chain_source) = self.chain_source {
729 monitor.load_outputs_to_watch(chain_source);
731 entry.insert(MonitorHolder {
733 pending_monitor_updates: Mutex::new(pending_monitor_updates),
734 last_chain_persist_height: AtomicUsize::new(self.highest_chain_height.load(Ordering::Acquire)),
739 fn update_channel(&self, funding_txo: OutPoint, update: &ChannelMonitorUpdate) -> ChannelMonitorUpdateStatus {
740 // Update the monitor that watches the channel referred to by the given outpoint.
741 let monitors = self.monitors.read().unwrap();
742 let ret = match monitors.get(&funding_txo) {
744 log_error!(self.logger, "Failed to update channel monitor: no such monitor registered");
746 // We should never ever trigger this from within ChannelManager. Technically a
747 // user could use this object with some proxying in between which makes this
748 // possible, but in tests and fuzzing, this should be a panic.
749 #[cfg(debug_assertions)]
750 panic!("ChannelManager generated a channel update for a channel that was not yet registered!");
751 #[cfg(not(debug_assertions))]
752 ChannelMonitorUpdateStatus::InProgress
754 Some(monitor_state) => {
755 let monitor = &monitor_state.monitor;
756 log_trace!(self.logger, "Updating ChannelMonitor for channel {}", log_funding_info!(monitor));
757 let update_res = monitor.update_monitor(update, &self.broadcaster, &*self.fee_estimator, &self.logger);
758 if update_res.is_err() {
759 log_error!(self.logger, "Failed to update ChannelMonitor for channel {}.", log_funding_info!(monitor));
761 // Even if updating the monitor returns an error, the monitor's state will
762 // still be changed. So, persist the updated monitor despite the error.
763 let update_id = MonitorUpdateId::from_monitor_update(update);
764 let mut pending_monitor_updates = monitor_state.pending_monitor_updates.lock().unwrap();
765 let persist_res = self.persister.update_persisted_channel(funding_txo, Some(update), monitor, update_id);
767 ChannelMonitorUpdateStatus::InProgress => {
768 pending_monitor_updates.push(update_id);
769 log_debug!(self.logger, "Persistence of ChannelMonitorUpdate for channel {} in progress", log_funding_info!(monitor));
771 ChannelMonitorUpdateStatus::Completed => {
772 log_debug!(self.logger, "Persistence of ChannelMonitorUpdate for channel {} completed", log_funding_info!(monitor));
774 ChannelMonitorUpdateStatus::UnrecoverableError => { /* we'll panic in a moment */ },
776 if update_res.is_err() {
777 ChannelMonitorUpdateStatus::InProgress
783 if let ChannelMonitorUpdateStatus::UnrecoverableError = ret {
784 // Take the monitors lock for writing so that we poison it and any future
785 // operations going forward fail immediately.
786 core::mem::drop(monitors);
787 let _poison = self.monitors.write().unwrap();
788 let err_str = "ChannelMonitor[Update] persistence failed unrecoverably. This indicates we cannot continue normal operation and must shut down.";
789 log_error!(self.logger, "{}", err_str);
790 panic!("{}", err_str);
795 fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)> {
796 let mut pending_monitor_events = self.pending_monitor_events.lock().unwrap().split_off(0);
797 for monitor_state in self.monitors.read().unwrap().values() {
798 let is_pending_monitor_update = monitor_state.has_pending_chainsync_updates(&monitor_state.pending_monitor_updates.lock().unwrap());
799 if is_pending_monitor_update &&
800 monitor_state.last_chain_persist_height.load(Ordering::Acquire) + LATENCY_GRACE_PERIOD_BLOCKS as usize
801 > self.highest_chain_height.load(Ordering::Acquire)
803 log_debug!(self.logger, "A Channel Monitor sync is still in progress, refusing to provide monitor events!");
805 if is_pending_monitor_update {
806 log_error!(self.logger, "A ChannelMonitor sync took longer than {} blocks to complete.", LATENCY_GRACE_PERIOD_BLOCKS);
807 log_error!(self.logger, " To avoid funds-loss, we are allowing monitor updates to be released.");
808 log_error!(self.logger, " This may cause duplicate payment events to be generated.");
810 let monitor_events = monitor_state.monitor.get_and_clear_pending_monitor_events();
811 if monitor_events.len() > 0 {
812 let monitor_outpoint = monitor_state.monitor.get_funding_txo().0;
813 let counterparty_node_id = monitor_state.monitor.get_counterparty_node_id();
814 pending_monitor_events.push((monitor_outpoint, monitor_events, counterparty_node_id));
818 pending_monitor_events
822 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref> events::EventsProvider for ChainMonitor<ChannelSigner, C, T, F, L, P>
823 where C::Target: chain::Filter,
824 T::Target: BroadcasterInterface,
825 F::Target: FeeEstimator,
827 P::Target: Persist<ChannelSigner>,
829 /// Processes [`SpendableOutputs`] events produced from each [`ChannelMonitor`] upon maturity.
831 /// For channels featuring anchor outputs, this method will also process [`BumpTransaction`]
832 /// events produced from each [`ChannelMonitor`] while there is a balance to claim onchain
833 /// within each channel. As the confirmation of a commitment transaction may be critical to the
834 /// safety of funds, we recommend invoking this every 30 seconds, or lower if running in an
835 /// environment with spotty connections, like on mobile.
837 /// An [`EventHandler`] may safely call back to the provider, though this shouldn't be needed in
838 /// order to handle these events.
840 /// [`SpendableOutputs`]: events::Event::SpendableOutputs
841 /// [`BumpTransaction`]: events::Event::BumpTransaction
842 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {
843 for monitor_state in self.monitors.read().unwrap().values() {
844 monitor_state.monitor.process_pending_events(&handler);
851 use crate::check_added_monitors;
852 use crate::{expect_payment_claimed, expect_payment_path_successful, get_event_msg};
853 use crate::{get_htlc_update_msgs, get_local_commitment_txn, get_revoke_commit_msgs, get_route_and_payment_hash, unwrap_send_err};
854 use crate::chain::{ChannelMonitorUpdateStatus, Confirm, Watch};
855 use crate::chain::channelmonitor::LATENCY_GRACE_PERIOD_BLOCKS;
856 use crate::events::{Event, MessageSendEvent, MessageSendEventsProvider};
857 use crate::ln::channelmanager::{PaymentSendFailure, PaymentId, RecipientOnionFields};
858 use crate::ln::functional_test_utils::*;
859 use crate::ln::msgs::ChannelMessageHandler;
860 use crate::util::errors::APIError;
863 fn test_async_ooo_offchain_updates() {
864 // Test that if we have multiple offchain updates being persisted and they complete
865 // out-of-order, the ChainMonitor waits until all have completed before informing the
867 let chanmon_cfgs = create_chanmon_cfgs(2);
868 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
869 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
870 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
871 create_announced_chan_between_nodes(&nodes, 0, 1);
873 // Route two payments to be claimed at the same time.
874 let (payment_preimage_1, payment_hash_1, ..) = route_payment(&nodes[0], &[&nodes[1]], 1_000_000);
875 let (payment_preimage_2, payment_hash_2, ..) = route_payment(&nodes[0], &[&nodes[1]], 1_000_000);
877 chanmon_cfgs[1].persister.offchain_monitor_updates.lock().unwrap().clear();
878 chanmon_cfgs[1].persister.set_update_ret(ChannelMonitorUpdateStatus::InProgress);
879 chanmon_cfgs[1].persister.set_update_ret(ChannelMonitorUpdateStatus::InProgress);
881 nodes[1].node.claim_funds(payment_preimage_1);
882 check_added_monitors!(nodes[1], 1);
883 nodes[1].node.claim_funds(payment_preimage_2);
884 check_added_monitors!(nodes[1], 1);
886 let persistences = chanmon_cfgs[1].persister.offchain_monitor_updates.lock().unwrap().clone();
887 assert_eq!(persistences.len(), 1);
888 let (funding_txo, updates) = persistences.iter().next().unwrap();
889 assert_eq!(updates.len(), 2);
891 // Note that updates is a HashMap so the ordering here is actually random. This shouldn't
892 // fail either way but if it fails intermittently it's depending on the ordering of updates.
893 let mut update_iter = updates.iter();
894 let next_update = update_iter.next().unwrap().clone();
895 // Should contain next_update when pending updates listed.
896 #[cfg(not(c_bindings))]
897 assert!(nodes[1].chain_monitor.chain_monitor.list_pending_monitor_updates().get(funding_txo)
898 .unwrap().contains(&next_update));
900 assert!(nodes[1].chain_monitor.chain_monitor.list_pending_monitor_updates().iter()
901 .find(|(txo, _)| txo == funding_txo).unwrap().1.contains(&next_update));
902 nodes[1].chain_monitor.chain_monitor.channel_monitor_updated(*funding_txo, next_update.clone()).unwrap();
903 // Should not contain the previously pending next_update when pending updates listed.
904 #[cfg(not(c_bindings))]
905 assert!(!nodes[1].chain_monitor.chain_monitor.list_pending_monitor_updates().get(funding_txo)
906 .unwrap().contains(&next_update));
908 assert!(!nodes[1].chain_monitor.chain_monitor.list_pending_monitor_updates().iter()
909 .find(|(txo, _)| txo == funding_txo).unwrap().1.contains(&next_update));
910 assert!(nodes[1].chain_monitor.release_pending_monitor_events().is_empty());
911 assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
912 assert!(nodes[1].node.get_and_clear_pending_events().is_empty());
913 nodes[1].chain_monitor.chain_monitor.channel_monitor_updated(*funding_txo, update_iter.next().unwrap().clone()).unwrap();
915 let claim_events = nodes[1].node.get_and_clear_pending_events();
916 assert_eq!(claim_events.len(), 2);
917 match claim_events[0] {
918 Event::PaymentClaimed { ref payment_hash, amount_msat: 1_000_000, .. } => {
919 assert_eq!(payment_hash_1, *payment_hash);
921 _ => panic!("Unexpected event"),
923 match claim_events[1] {
924 Event::PaymentClaimed { ref payment_hash, amount_msat: 1_000_000, .. } => {
925 assert_eq!(payment_hash_2, *payment_hash);
927 _ => panic!("Unexpected event"),
930 // Now manually walk the commitment signed dance - because we claimed two payments
931 // back-to-back it doesn't fit into the neat walk commitment_signed_dance does.
933 let updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
934 nodes[0].node.handle_update_fulfill_htlc(&nodes[1].node.get_our_node_id(), &updates.update_fulfill_htlcs[0]);
935 expect_payment_sent(&nodes[0], payment_preimage_1, None, false, false);
936 nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &updates.commitment_signed);
937 check_added_monitors!(nodes[0], 1);
938 let (as_first_raa, as_first_update) = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
940 nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_first_raa);
941 check_added_monitors!(nodes[1], 1);
942 let bs_second_updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
943 nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_first_update);
944 check_added_monitors!(nodes[1], 1);
945 let bs_first_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
947 nodes[0].node.handle_update_fulfill_htlc(&nodes[1].node.get_our_node_id(), &bs_second_updates.update_fulfill_htlcs[0]);
948 expect_payment_sent(&nodes[0], payment_preimage_2, None, false, false);
949 nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_second_updates.commitment_signed);
950 check_added_monitors!(nodes[0], 1);
951 nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_first_raa);
952 expect_payment_path_successful!(nodes[0]);
953 check_added_monitors!(nodes[0], 1);
954 let (as_second_raa, as_second_update) = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
956 nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_second_raa);
957 check_added_monitors!(nodes[1], 1);
958 nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_second_update);
959 check_added_monitors!(nodes[1], 1);
960 let bs_second_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
962 nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_second_raa);
963 expect_payment_path_successful!(nodes[0]);
964 check_added_monitors!(nodes[0], 1);
967 fn do_chainsync_pauses_events(block_timeout: bool) {
968 // When a chainsync monitor update occurs, any MonitorUpdates should be held before being
969 // passed upstream to a `ChannelManager` via `Watch::release_pending_monitor_events`. This
970 // tests that behavior, as well as some ways it might go wrong.
971 let chanmon_cfgs = create_chanmon_cfgs(2);
972 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
973 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
974 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
975 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
977 // Get a route for later and rebalance the channel somewhat
978 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
979 let (route, second_payment_hash, _, second_payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[1], 100_000);
981 // First route a payment that we will claim on chain and give the recipient the preimage.
982 let (payment_preimage, payment_hash, ..) = route_payment(&nodes[0], &[&nodes[1]], 1_000_000);
983 nodes[1].node.claim_funds(payment_preimage);
984 expect_payment_claimed!(nodes[1], payment_hash, 1_000_000);
985 nodes[1].node.get_and_clear_pending_msg_events();
986 check_added_monitors!(nodes[1], 1);
987 let remote_txn = get_local_commitment_txn!(nodes[1], channel.2);
988 assert_eq!(remote_txn.len(), 2);
990 // Temp-fail the block connection which will hold the channel-closed event
991 chanmon_cfgs[0].persister.chain_sync_monitor_persistences.lock().unwrap().clear();
992 chanmon_cfgs[0].persister.set_update_ret(ChannelMonitorUpdateStatus::InProgress);
994 // Connect B's commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
995 // channel is now closed, but the ChannelManager doesn't know that yet.
996 let new_header = create_dummy_header(nodes[0].best_block_info().0, 0);
997 nodes[0].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
998 &[(0, &remote_txn[0]), (1, &remote_txn[1])], nodes[0].best_block_info().1 + 1);
999 assert!(nodes[0].chain_monitor.release_pending_monitor_events().is_empty());
1000 nodes[0].chain_monitor.chain_monitor.best_block_updated(&new_header, nodes[0].best_block_info().1 + 1);
1001 assert!(nodes[0].chain_monitor.release_pending_monitor_events().is_empty());
1003 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
1004 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
1005 chanmon_cfgs[0].persister.set_update_ret(ChannelMonitorUpdateStatus::Completed);
1006 unwrap_send_err!(nodes[0].node.send_payment_with_route(&route, second_payment_hash,
1007 RecipientOnionFields::secret_only(second_payment_secret), PaymentId(second_payment_hash.0)
1008 ), false, APIError::MonitorUpdateInProgress, {});
1009 check_added_monitors!(nodes[0], 1);
1011 // However, as the ChainMonitor is still waiting for the original persistence to complete,
1012 // it won't yet release the MonitorEvents.
1013 assert!(nodes[0].chain_monitor.release_pending_monitor_events().is_empty());
1016 // After three blocks, pending MontiorEvents should be released either way.
1017 let latest_header = create_dummy_header(nodes[0].best_block_info().0, 0);
1018 nodes[0].chain_monitor.chain_monitor.best_block_updated(&latest_header, nodes[0].best_block_info().1 + LATENCY_GRACE_PERIOD_BLOCKS);
1020 let persistences = chanmon_cfgs[0].persister.chain_sync_monitor_persistences.lock().unwrap().clone();
1021 for (funding_outpoint, update_ids) in persistences {
1022 for update_id in update_ids {
1023 nodes[0].chain_monitor.chain_monitor.channel_monitor_updated(funding_outpoint, update_id).unwrap();
1028 expect_payment_sent(&nodes[0], payment_preimage, None, true, false);
1032 fn chainsync_pauses_events() {
1033 do_chainsync_pauses_events(false);
1034 do_chainsync_pauses_events(true);
1038 #[cfg(feature = "std")]
1039 fn update_during_chainsync_poisons_channel() {
1040 let chanmon_cfgs = create_chanmon_cfgs(2);
1041 let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
1042 let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
1043 let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
1044 create_announced_chan_between_nodes(&nodes, 0, 1);
1046 chanmon_cfgs[0].persister.chain_sync_monitor_persistences.lock().unwrap().clear();
1047 chanmon_cfgs[0].persister.set_update_ret(ChannelMonitorUpdateStatus::UnrecoverableError);
1049 assert!(std::panic::catch_unwind(|| {
1050 // Returning an UnrecoverableError should always panic immediately
1051 connect_blocks(&nodes[0], 1);
1053 assert!(std::panic::catch_unwind(|| {
1054 // ...and also poison our locks causing later use to panic as well
1055 core::mem::drop(nodes);