Extend update_monitor logging
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index 93a4edb6e3c4cf4499afda966688db17c07dad69..2428f0c9ee3676ab763caaf2de41315eab2a1288 100644 (file)
@@ -64,14 +64,29 @@ pub struct ChannelMonitorUpdate {
        pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
        /// The sequence number of this update. Updates *must* be replayed in-order according to this
        /// sequence number (and updates may panic if they are not). The update_id values are strictly
-       /// increasing and increase by one for each new update.
+       /// increasing and increase by one for each new update, with one exception specified below.
        ///
        /// This sequence number is also used to track up to which points updates which returned
        /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
        /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
+       ///
+       /// The only instance where update_id values are not strictly increasing is the case where we
+       /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
+       /// its docs for more details.
+       ///
+       /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
        pub update_id: u64,
 }
 
+/// If:
+///    (1) a channel has been force closed and
+///    (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
+///        this channel's (the backward link's) broadcasted commitment transaction
+/// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
+/// with the update providing said payment preimage. No other update types are allowed after
+/// force-close.
+pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
+
 impl Writeable for ChannelMonitorUpdate {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
                self.update_id.write(w)?;
@@ -95,7 +110,7 @@ impl Readable for ChannelMonitorUpdate {
 }
 
 /// An error enum representing a failure to persist a channel monitor update.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum ChannelMonitorUpdateErr {
        /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
        /// our state failed, but is expected to succeed at some point in the future).
@@ -159,7 +174,7 @@ pub enum ChannelMonitorUpdateErr {
 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
 /// corrupted.
-/// Contains a human-readable error message.
+/// Contains a developer-readable error message.
 #[derive(Debug)]
 pub struct MonitorUpdateError(pub &'static str);
 
@@ -746,7 +761,7 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
        /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
        /// returned block hash and the the current chain and then reconnecting blocks to get to the
        /// best chain) upon deserializing the object!
-       pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
+       pub fn serialize_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
                //TODO: We still write out all the serialization here manually instead of using the fancy
                //serialization framework we have, we should migrate things over to it.
                writer.write_all(&[SERIALIZATION_VERSION; 1])?;
@@ -1144,7 +1159,11 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
        /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
        /// commitment_tx_infos which contain the payment hash have been revoked.
-       pub(crate) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
+       pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
+       where B::Target: BroadcasterInterface,
+                   F::Target: FeeEstimator,
+                   L::Target: Logger,
+       {
                self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
        }
 
@@ -1162,28 +1181,47 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        /// itself.
        ///
        /// panics if the given update is not the next update by update_id.
-       pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
-               where B::Target: BroadcasterInterface,
-                                       L::Target: Logger,
+       pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
+       where B::Target: BroadcasterInterface,
+                   F::Target: FeeEstimator,
+                   L::Target: Logger,
        {
-               if self.latest_update_id + 1 != updates.update_id {
+               // ChannelMonitor updates may be applied after force close if we receive a
+               // preimage for a broadcasted commitment transaction HTLC output that we'd
+               // like to claim on-chain. If this is the case, we no longer have guaranteed
+               // access to the monitor's update ID, so we use a sentinel value instead.
+               if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
+                       match updates.updates[0] {
+                               ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
+                               _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
+                       }
+                       assert_eq!(updates.updates.len(), 1);
+               } else if self.latest_update_id + 1 != updates.update_id {
                        panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
                }
-               for update in updates.updates.drain(..) {
+               for update in updates.updates.iter() {
                        match update {
                                ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
+                                       log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
                                        if self.lockdown_from_offchain { panic!(); }
-                                       self.provide_latest_holder_commitment_tx_info(commitment_tx, htlc_outputs)?
+                                       self.provide_latest_holder_commitment_tx_info(commitment_tx.clone(), htlc_outputs.clone())?
+                               },
+                               ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } => {
+                                       log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
+                                       self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
+                               },
+                               ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
+                                       log_trace!(logger, "Updating ChannelMonitor with payment preimage");
+                                       self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
+                               },
+                               ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
+                                       log_trace!(logger, "Updating ChannelMonitor with commitment secret");
+                                       self.provide_secret(*idx, *secret)?
                                },
-                               ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
-                                       self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
-                               ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
-                                       self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
-                               ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
-                                       self.provide_secret(idx, secret)?,
                                ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
+                                       log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
                                        self.lockdown_from_offchain = true;
-                                       if should_broadcast {
+                                       if *should_broadcast {
                                                self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
                                        } else {
                                                log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
@@ -2141,10 +2179,10 @@ pub trait Persist<Keys: ChannelKeys>: Send + Sync {
        /// stored channel data). Note that you **must** persist every new monitor to
        /// disk. See the `Persist` trait documentation for more details.
        ///
-       /// See [`ChannelMonitor::write_for_disk`] for writing out a `ChannelMonitor`,
+       /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
        /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
        ///
-       /// [`ChannelMonitor::write_for_disk`]: struct.ChannelMonitor.html#method.write_for_disk
+       /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
        /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
        fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
 
@@ -2167,12 +2205,12 @@ pub trait Persist<Keys: ChannelKeys>: Send + Sync {
        /// them in batches. The size of each monitor grows `O(number of state updates)`
        /// whereas updates are small and `O(1)`.
        ///
-       /// See [`ChannelMonitor::write_for_disk`] for writing out a `ChannelMonitor`,
+       /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
        /// [`ChannelMonitorUpdate::write`] for writing out an update, and
        /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
        ///
        /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
-       /// [`ChannelMonitor::write_for_disk`]: struct.ChannelMonitor.html#method.write_for_disk
+       /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
        /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
        /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
        fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
@@ -2486,16 +2524,18 @@ mod tests {
        use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
        use ln::chan_utils;
        use ln::chan_utils::{HTLCOutputInCommitment, HolderCommitmentTransaction};
-       use util::test_utils::TestLogger;
+       use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
        use bitcoin::secp256k1::key::{SecretKey,PublicKey};
        use bitcoin::secp256k1::Secp256k1;
-       use std::sync::Arc;
+       use std::sync::{Arc, Mutex};
        use chain::keysinterface::InMemoryChannelKeys;
 
        #[test]
        fn test_prune_preimages() {
                let secp_ctx = Secp256k1::new();
                let logger = Arc::new(TestLogger::new());
+               let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
+               let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
 
                let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
@@ -2571,7 +2611,7 @@ mod tests {
                monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
                monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
                for &(ref preimage, ref hash) in preimages.iter() {
-                       monitor.provide_payment_preimage(hash, preimage);
+                       monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
                }
 
                // Now provide a secret, pruning preimages 10-15