Merge pull request #1748 from valentinewallace/2022-10-custom-oms
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index bfb6e1ab3a8b72f363d948c539fd2ee212540bfa..7c6b48d144b79b06c67105cc50d609f238b7581f 100644 (file)
@@ -21,8 +21,7 @@
 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
 
 use bitcoin::blockdata::block::BlockHeader;
-use bitcoin::blockdata::transaction::{TxOut,Transaction};
-use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
+use bitcoin::blockdata::transaction::{OutPoint as BitcoinOutPoint, TxOut, Transaction};
 use bitcoin::blockdata::script::{Script, Builder};
 use bitcoin::blockdata::opcodes;
 
@@ -44,6 +43,8 @@ use chain::{BestBlock, WatchedOutput};
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
 use chain::transaction::{OutPoint, TransactionData};
 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
+#[cfg(anchors)]
+use chain::onchaintx::ClaimEvent;
 use chain::onchaintx::OnchainTxHandler;
 use chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
 use chain::Filter;
@@ -51,6 +52,8 @@ use util::logger::Logger;
 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48, OptionDeserWrapper};
 use util::byte_utils;
 use util::events::Event;
+#[cfg(anchors)]
+use util::events::{AnchorDescriptor, BumpTransactionEvent};
 
 use prelude::*;
 use core::{cmp, mem};
@@ -66,7 +69,7 @@ use sync::Mutex;
 /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
 /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
 /// transaction), a single update may reach upwards of 1 MiB in serialized size.
-#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq))]
+#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
 #[derive(Clone)]
 #[must_use]
 pub struct ChannelMonitorUpdate {
@@ -76,12 +79,14 @@ pub struct ChannelMonitorUpdate {
        /// 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
+       /// [`ChannelMonitorUpdateStatus::InProgress`] 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.
+       ///
+       /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
        pub update_id: u64,
 }
 
@@ -123,7 +128,7 @@ impl Readable for ChannelMonitorUpdate {
 }
 
 /// An event to be processed by the ChannelManager.
-#[derive(Clone, PartialEq)]
+#[derive(Clone, PartialEq, Eq)]
 pub enum MonitorEvent {
        /// A monitor event containing an HTLCUpdate.
        HTLCEvent(HTLCUpdate),
@@ -132,10 +137,10 @@ pub enum MonitorEvent {
        CommitmentTxConfirmed(OutPoint),
 
        /// Indicates a [`ChannelMonitor`] update has completed. See
-       /// [`ChannelMonitorUpdateErr::TemporaryFailure`] for more information on how this is used.
+       /// [`ChannelMonitorUpdateStatus::InProgress`] for more information on how this is used.
        ///
-       /// [`ChannelMonitorUpdateErr::TemporaryFailure`]: super::ChannelMonitorUpdateErr::TemporaryFailure
-       UpdateCompleted {
+       /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
+       Completed {
                /// The funding outpoint of the [`ChannelMonitor`] that was updated
                funding_txo: OutPoint,
                /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
@@ -147,15 +152,15 @@ pub enum MonitorEvent {
        },
 
        /// Indicates a [`ChannelMonitor`] update has failed. See
-       /// [`ChannelMonitorUpdateErr::PermanentFailure`] for more information on how this is used.
+       /// [`ChannelMonitorUpdateStatus::PermanentFailure`] for more information on how this is used.
        ///
-       /// [`ChannelMonitorUpdateErr::PermanentFailure`]: super::ChannelMonitorUpdateErr::PermanentFailure
+       /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
        UpdateFailed(OutPoint),
 }
 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
-       // Note that UpdateCompleted and UpdateFailed are currently never serialized to disk as they are
+       // Note that Completed and UpdateFailed are currently never serialized to disk as they are
        // generated only in ChainMonitor
-       (0, UpdateCompleted) => {
+       (0, Completed) => {
                (0, funding_txo, required),
                (2, monitor_update_id, required),
        },
@@ -168,7 +173,7 @@ impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
 /// preimage claim backward will lead to loss of funds.
-#[derive(Clone, PartialEq)]
+#[derive(Clone, PartialEq, Eq)]
 pub struct HTLCUpdate {
        pub(crate) payment_hash: PaymentHash,
        pub(crate) payment_preimage: Option<PaymentPreimage>,
@@ -234,7 +239,7 @@ pub const ANTI_REORG_DELAY: u32 = 6;
 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
 
 // TODO(devrandom) replace this with HolderCommitmentTransaction
-#[derive(Clone, PartialEq)]
+#[derive(Clone, PartialEq, Eq)]
 struct HolderSignedTx {
        /// txid of the transaction in tx, just used to make comparison faster
        txid: Txid,
@@ -261,9 +266,23 @@ impl_writeable_tlv_based!(HolderSignedTx, {
        (14, htlc_outputs, vec_type)
 });
 
+#[cfg(anchors)]
+impl HolderSignedTx {
+       fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
+               self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
+                       if let Some(_) = htlc.transaction_output_index {
+                               Some(htlc.clone())
+                       } else {
+                               None
+                       }
+               })
+               .collect()
+       }
+}
+
 /// We use this to track static counterparty commitment transaction data and to generate any
 /// justice or 2nd-stage preimage/timeout transactions.
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq)]
 struct CounterpartyCommitmentParameters {
        counterparty_delayed_payment_base_key: PublicKey,
        counterparty_htlc_base_key: PublicKey,
@@ -317,7 +336,7 @@ impl Readable for CounterpartyCommitmentParameters {
 /// transaction causing it.
 ///
 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq)]
 struct OnchainEventEntry {
        txid: Txid,
        height: u32,
@@ -359,7 +378,7 @@ type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
 
 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq)]
 enum OnchainEvent {
        /// An outbound HTLC failing after a transaction is confirmed. Used
        ///  * when an outbound HTLC output is spent by us after the HTLC timed out
@@ -469,7 +488,7 @@ impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
 
 );
 
-#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq))]
+#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
 #[derive(Clone)]
 pub(crate) enum ChannelMonitorUpdateStep {
        LatestHolderCommitmentTXInfo {
@@ -617,7 +636,7 @@ pub enum Balance {
 }
 
 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq)]
 struct IrrevocablyResolvedHTLC {
        commitment_tx_output_idx: Option<u32>,
        /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
@@ -1219,7 +1238,7 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                B::Target: BroadcasterInterface,
                L::Target: Logger,
        {
-               self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
+               self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
        }
 
        /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
@@ -1314,14 +1333,20 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
        }
 
        /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
-       /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
-       /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
-       /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
-       /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
-       /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
-       /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
-       /// out-of-band the other node operator to coordinate with him if option is available to you.
-       /// In any-case, choice is up to the user.
+       /// the Channel was out-of-date.
+       ///
+       /// You may also use this to broadcast the latest local commitment transaction, either because
+       /// a monitor update failed with [`ChannelMonitorUpdateStatus::PermanentFailure`] or because we've
+       /// fallen behind (i.e. we've received proof that our counterparty side knows a revocation
+       /// secret we gave them that they shouldn't know).
+       ///
+       /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
+       /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
+       /// close channel with their commitment transaction after a substantial amount of time. Best
+       /// may be to contact the other node operator out-of-band to coordinate other options available
+       /// to you. In any-case, the choice is up to you.
+       ///
+       /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
        pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
        where L::Target: Logger {
                self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
@@ -2214,6 +2239,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
                }
                let mut ret = Ok(());
+               let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
                for update in updates.updates.iter() {
                        match update {
                                ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
@@ -2231,7 +2257,6 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                },
                                ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
                                        log_trace!(logger, "Updating ChannelMonitor with payment preimage");
-                                       let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
                                        self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
                                },
                                ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
@@ -2247,8 +2272,29 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        self.lockdown_from_offchain = true;
                                        if *should_broadcast {
                                                self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
+                                               // If the channel supports anchor outputs, we'll need to emit an external
+                                               // event to be consumed such that a child transaction is broadcast with a
+                                               // high enough feerate for the parent commitment transaction to confirm.
+                                               if self.onchain_tx_handler.opt_anchors() {
+                                                       let funding_output = HolderFundingOutput::build(
+                                                               self.funding_redeemscript.clone(), self.channel_value_satoshis,
+                                                               self.onchain_tx_handler.opt_anchors(),
+                                                       );
+                                                       let best_block_height = self.best_block.height();
+                                                       let commitment_package = PackageTemplate::build_package(
+                                                               self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
+                                                               PackageSolvingData::HolderFundingOutput(funding_output),
+                                                               best_block_height, false, best_block_height,
+                                                       );
+                                                       self.onchain_tx_handler.update_claims_view(
+                                                               &[], vec![commitment_package], best_block_height, best_block_height,
+                                                               broadcaster, &bounded_fee_estimator, logger,
+                                                       );
+                                               }
                                        } else if !self.holder_tx_signed {
-                                               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");
+                                               log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
+                                               log_error!(logger, "    in channel monitor for channel {}!", log_bytes!(self.funding_info.0.to_channel_id()));
+                                               log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
                                        } else {
                                                // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
                                                // will still give us a ChannelForceClosed event with !should_broadcast, but we
@@ -2299,6 +2345,34 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
                let mut ret = Vec::new();
                mem::swap(&mut ret, &mut self.pending_events);
+               #[cfg(anchors)]
+               for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
+                       match claim_event {
+                               ClaimEvent::BumpCommitment {
+                                       package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
+                               } => {
+                                       let commitment_txid = commitment_tx.txid();
+                                       debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
+                                       let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
+                                       let commitment_tx_fee_satoshis = self.channel_value_satoshis -
+                                               commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
+                                       ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
+                                               package_target_feerate_sat_per_1000_weight,
+                                               commitment_tx,
+                                               commitment_tx_fee_satoshis,
+                                               anchor_descriptor: AnchorDescriptor {
+                                                       channel_keys_id: self.channel_keys_id,
+                                                       channel_value_satoshis: self.channel_value_satoshis,
+                                                       outpoint: BitcoinOutPoint {
+                                                               txid: commitment_txid,
+                                                               vout: anchor_output_idx,
+                                                       },
+                                               },
+                                               pending_htlcs,
+                                       }));
+                               },
+                       }
+               }
                ret
        }
 
@@ -2511,13 +2585,13 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                        CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
                                                                self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
                                                                self.counterparty_commitment_params.counterparty_htlc_base_key,
-                                                               preimage.unwrap(), htlc.clone()))
+                                                               preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
                                        } else {
                                                PackageSolvingData::CounterpartyReceivedHTLCOutput(
                                                        CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
                                                                self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
                                                                self.counterparty_commitment_params.counterparty_htlc_base_key,
-                                                               htlc.clone()))
+                                                               htlc.clone(), self.onchain_tx_handler.opt_anchors()))
                                        };
                                        let aggregation = if !htlc.offered { false } else { true };
                                        let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
@@ -2816,7 +2890,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
                                                txid,
                                                transaction: Some((*tx).clone()),
-                                               height: height,
+                                               height,
                                                event: OnchainEvent::FundingSpendConfirmation {
                                                        on_local_output_csv: balance_spendable_csv,
                                                        commitment_tx_to_counterparty_output,
@@ -2874,21 +2948,26 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
 
                let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
                if should_broadcast {
-                       let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone());
+                       let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
                        let commitment_package = PackageTemplate::build_package(self.funding_info.0.txid.clone(), self.funding_info.0.index as u32, PackageSolvingData::HolderFundingOutput(funding_outp), self.best_block.height(), false, self.best_block.height());
                        claimable_outpoints.push(commitment_package);
                        self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
                        let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
                        self.holder_tx_signed = true;
-                       // Because we're broadcasting a commitment transaction, we should construct the package
-                       // assuming it gets confirmed in the next block. Sadly, we have code which considers
-                       // "not yet confirmed" things as discardable, so we cannot do that here.
-                       let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
-                       let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
-                       if !new_outputs.is_empty() {
-                               watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
+                       // We can't broadcast our HTLC transactions while the commitment transaction is
+                       // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
+                       // `transactions_confirmed`.
+                       if !self.onchain_tx_handler.opt_anchors() {
+                               // Because we're broadcasting a commitment transaction, we should construct the package
+                               // assuming it gets confirmed in the next block. Sadly, we have code which considers
+                               // "not yet confirmed" things as discardable, so we cannot do that here.
+                               let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
+                               let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
+                               if !new_outputs.is_empty() {
+                                       watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
+                               }
+                               claimable_outpoints.append(&mut new_outpoints);
                        }
-                       claimable_outpoints.append(&mut new_outpoints);
                }
 
                // Find which on-chain events have reached their confirmation threshold.
@@ -3162,8 +3241,10 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        let htlc_claim = HTLCClaim::from_witness(&input.witness);
                        let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
                        let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
+                       #[cfg(not(fuzzing))]
                        let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
                        let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
+                       #[cfg(not(fuzzing))]
                        let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
 
                        let mut payment_preimage = PaymentPreimage([0; 32]);
@@ -3406,7 +3487,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                        let entry = OnchainEventEntry {
                                txid: tx.txid(),
                                transaction: Some(tx.clone()),
-                               height: height,
+                               height,
                                event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
                        };
                        log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
@@ -3765,8 +3846,7 @@ mod tests {
        use ln::{PaymentPreimage, PaymentHash};
        use ln::chan_utils;
        use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
-       use ln::channelmanager::PaymentSendFailure;
-       use ln::features::InitFeatures;
+       use ln::channelmanager::{self, PaymentSendFailure};
        use ln::functional_test_utils::*;
        use ln::script::ShutdownScript;
        use util::errors::APIError;
@@ -3795,9 +3875,9 @@ mod tests {
                let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
                let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
                let channel = create_announced_chan_between_nodes(
-                       &nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+                       &nodes, 0, 1, channelmanager::provided_init_features(), channelmanager::provided_init_features());
                create_announced_chan_between_nodes(
-                       &nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
+                       &nodes, 1, 2, channelmanager::provided_init_features(), channelmanager::provided_init_features());
 
                // Rebalance somewhat
                send_payment(&nodes[0], &[&nodes[1]], 10_000_000);