Merge pull request #2430 from TheBlueMatt/2023-07-116-bindings-part-1
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index 7a69be7dcdf5f7daad8ae6425c076403b1aea3ab..f98c0bcac8c0ef453d281b700272b8ac69dd4d06 100644 (file)
@@ -42,18 +42,15 @@ use crate::chain;
 use crate::chain::{BestBlock, WatchedOutput};
 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
 use crate::chain::transaction::{OutPoint, TransactionData};
-use crate::chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
-#[cfg(anchors)]
-use crate::chain::onchaintx::ClaimEvent;
-use crate::chain::onchaintx::OnchainTxHandler;
+use crate::sign::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
+use crate::chain::onchaintx::{ClaimEvent, OnchainTxHandler};
 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
 use crate::chain::Filter;
 use crate::util::logger::Logger;
 use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48};
 use crate::util::byte_utils;
-use crate::events::Event;
-#[cfg(anchors)]
-use crate::events::bump_transaction::{AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
+use crate::events::{Event, EventHandler};
+use crate::events::bump_transaction::{ChannelDerivationParameters, AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
 
 use crate::prelude::*;
 use core::{cmp, mem};
@@ -69,34 +66,36 @@ use crate::sync::{Mutex, LockTestExt};
 /// 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, Eq))]
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 #[must_use]
 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, with one exception specified below.
+       /// increasing and increase by one for each new update, with two exceptions specified below.
        ///
        /// This sequence number is also used to track up to which points updates which returned
        /// [`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.
+       /// The only instances we allow where update_id values are not strictly increasing have a
+       /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that
+       /// will force close the channel by broadcasting the latest commitment transaction or
+       /// special post-force-close updates, like providing preimages necessary to claim outputs on the
+       /// broadcast commitment transaction. See its docs for more details.
        ///
        /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
        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.
+/// The update ID used for a [`ChannelMonitorUpdate`] that is either:
+///
+///    (1) attempting to force close the channel by broadcasting our latest commitment transaction or
+///    (2) providing a preimage (after the channel has been force closed) from a forward link that
+///            allows us to spend an HTLC output on this channel's (the backward link's) broadcasted
+///            commitment transaction.
+///
+/// No other [`ChannelMonitorUpdate`]s are allowed after force-close.
 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
 
 impl Writeable for ChannelMonitorUpdate {
@@ -263,10 +262,9 @@ impl_writeable_tlv_based!(HolderSignedTx, {
        (8, delayed_payment_key, required),
        (10, per_commitment_point, required),
        (12, feerate_per_kw, required),
-       (14, htlc_outputs, vec_type)
+       (14, htlc_outputs, required_vec)
 });
 
-#[cfg(anchors)]
 impl HolderSignedTx {
        fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
                self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
@@ -488,13 +486,16 @@ impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
 
 );
 
-#[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 pub(crate) enum ChannelMonitorUpdateStep {
        LatestHolderCommitmentTXInfo {
                commitment_tx: HolderCommitmentTransaction,
+               /// Note that LDK after 0.0.115 supports this only containing dust HTLCs (implying the
+               /// `Signature` field is never filled in). At that point, non-dust HTLCs are implied by the
+               /// HTLC fields in `commitment_tx` and the sources passed via `nondust_htlc_sources`.
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
                claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
+               nondust_htlc_sources: Vec<HTLCSource>,
        },
        LatestCounterpartyCommitmentTXInfo {
                commitment_txid: Txid,
@@ -537,14 +538,15 @@ impl ChannelMonitorUpdateStep {
 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
        (0, LatestHolderCommitmentTXInfo) => {
                (0, commitment_tx, required),
-               (1, claimed_htlcs, vec_type),
-               (2, htlc_outputs, vec_type),
+               (1, claimed_htlcs, optional_vec),
+               (2, htlc_outputs, required_vec),
+               (4, nondust_htlc_sources, optional_vec),
        },
        (1, LatestCounterpartyCommitmentTXInfo) => {
                (0, commitment_txid, required),
                (2, commitment_number, required),
                (4, their_per_commitment_point, required),
-               (6, htlc_outputs, vec_type),
+               (6, htlc_outputs, required_vec),
        },
        (2, PaymentPreimage) => {
                (0, payment_preimage, required),
@@ -600,6 +602,10 @@ pub enum Balance {
                /// The height at which the counterparty may be able to claim the balance if we have not
                /// done so.
                timeout_height: u32,
+               /// The payment hash that locks this HTLC.
+               payment_hash: PaymentHash,
+               /// The preimage that can be used to claim this HTLC.
+               payment_preimage: PaymentPreimage,
        },
        /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
        /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
@@ -611,6 +617,8 @@ pub enum Balance {
                /// The height at which we will be able to claim the balance if our counterparty has not
                /// done so.
                claimable_height: u32,
+               /// The payment hash whose preimage our counterparty needs to claim this HTLC.
+               payment_hash: PaymentHash,
        },
        /// HTLCs which we received from our counterparty which are claimable with a preimage which we
        /// do not currently have. This will only be claimable if we receive the preimage from the node
@@ -622,6 +630,8 @@ pub enum Balance {
                /// The height at which our counterparty will be able to claim the balance if we have not
                /// yet received the preimage and claimed it ourselves.
                expiry_height: u32,
+               /// The payment hash whose preimage we need to claim this HTLC.
+               payment_hash: PaymentHash,
        },
        /// The channel has been closed, and our counterparty broadcasted a revoked commitment
        /// transaction.
@@ -637,6 +647,40 @@ pub enum Balance {
        },
 }
 
+impl Balance {
+       /// The amount claimable, in satoshis. This excludes balances that we are unsure if we are able
+       /// to claim, this is because we are waiting for a preimage or for a timeout to expire. For more
+       /// information on these balances see [`Balance::MaybeTimeoutClaimableHTLC`] and
+       /// [`Balance::MaybePreimageClaimableHTLC`].
+       ///
+       /// On-chain fees required to claim the balance are not included in this amount.
+       pub fn claimable_amount_satoshis(&self) -> u64 {
+               match self {
+                       Balance::ClaimableOnChannelClose {
+                               claimable_amount_satoshis,
+                       } => *claimable_amount_satoshis,
+                       Balance::ClaimableAwaitingConfirmations {
+                               claimable_amount_satoshis,
+                               ..
+                       } => *claimable_amount_satoshis,
+                       Balance::ContentiousClaimable {
+                               claimable_amount_satoshis,
+                               ..
+                       } => *claimable_amount_satoshis,
+                       Balance::MaybeTimeoutClaimableHTLC {
+                               ..
+                       } => 0,
+                       Balance::MaybePreimageClaimableHTLC {
+                               ..
+                       } => 0,
+                       Balance::CounterpartyRevokedOutputClaimable {
+                               claimable_amount_satoshis,
+                               ..
+                       } => *claimable_amount_satoshis,
+               }
+       }
+}
+
 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
 #[derive(PartialEq, Eq)]
 struct IrrevocablyResolvedHTLC {
@@ -694,11 +738,6 @@ impl Readable for IrrevocablyResolvedHTLC {
 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
 /// information and are actively monitoring the chain.
 ///
-/// Pending Events or updated HTLCs which have not yet been read out by
-/// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
-/// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
-/// gotten are fully handled before re-serializing the new state.
-///
 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
@@ -708,7 +747,7 @@ pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
        #[cfg(test)]
        pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
        #[cfg(not(test))]
-       inner: Mutex<ChannelMonitorImpl<Signer>>,
+       pub(super) inner: Mutex<ChannelMonitorImpl<Signer>>,
 }
 
 #[derive(PartialEq)]
@@ -785,7 +824,8 @@ pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
        // we further MUST NOT generate events during block/transaction-disconnection.
        pending_monitor_events: Vec<MonitorEvent>,
 
-       pending_events: Vec<Event>,
+       pub(super) pending_events: Vec<Event>,
+       pub(super) is_processing_pending_events: bool,
 
        // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
        // which to take actions once they reach enough confirmations. Each entry includes the
@@ -1031,12 +1071,12 @@ impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signe
 
                write_tlv_fields!(writer, {
                        (1, self.funding_spend_confirmed, option),
-                       (3, self.htlcs_resolved_on_chain, vec_type),
-                       (5, self.pending_monitor_events, vec_type),
+                       (3, self.htlcs_resolved_on_chain, required_vec),
+                       (5, self.pending_monitor_events, required_vec),
                        (7, self.funding_spend_seen, required),
                        (9, self.counterparty_node_id, option),
                        (11, self.confirmed_commitment_tx_counterparty_output, option),
-                       (13, self.spendable_txids_confirmed, vec_type),
+                       (13, self.spendable_txids_confirmed, required_vec),
                        (15, self.counterparty_fulfilled_htlcs, required),
                });
 
@@ -1044,6 +1084,42 @@ impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signe
        }
 }
 
+macro_rules! _process_events_body {
+       ($self_opt: expr, $event_to_handle: expr, $handle_event: expr) => {
+               loop {
+                       let (pending_events, repeated_events);
+                       if let Some(us) = $self_opt {
+                               let mut inner = us.inner.lock().unwrap();
+                               if inner.is_processing_pending_events {
+                                       break;
+                               }
+                               inner.is_processing_pending_events = true;
+
+                               pending_events = inner.pending_events.clone();
+                               repeated_events = inner.get_repeated_events();
+                       } else { break; }
+                       let num_events = pending_events.len();
+
+                       for event in pending_events.into_iter().chain(repeated_events.into_iter()) {
+                               $event_to_handle = event;
+                               $handle_event;
+                       }
+
+                       if let Some(us) = $self_opt {
+                               let mut inner = us.inner.lock().unwrap();
+                               inner.pending_events.drain(..num_events);
+                               inner.is_processing_pending_events = false;
+                               if !inner.pending_events.is_empty() {
+                                       // If there's more events to process, go ahead and do so.
+                                       continue;
+                               }
+                       }
+                       break;
+               }
+       }
+}
+pub(super) use _process_events_body as process_events_body;
+
 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
        /// For lockorder enforcement purposes, we need to have a single site which constructs the
        /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
@@ -1135,6 +1211,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
                        payment_preimages: HashMap::new(),
                        pending_monitor_events: Vec::new(),
                        pending_events: Vec::new(),
+                       is_processing_pending_events: false,
 
                        onchain_events_awaiting_threshold_conf: Vec::new(),
                        outputs_to_watch,
@@ -1180,7 +1257,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
                &self, holder_commitment_tx: HolderCommitmentTransaction,
                htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
        ) -> Result<(), ()> {
-               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new()).map_err(|_| ())
+               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new(), Vec::new()).map_err(|_| ())
        }
 
        /// This is used to provide payment preimage(s) out-of-band during startup without updating the
@@ -1201,17 +1278,6 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
                        payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
        }
 
-       pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
-               &self,
-               broadcaster: &B,
-               logger: &L,
-       ) where
-               B::Target: BroadcasterInterface,
-               L::Target: 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
        /// itself.
        ///
@@ -1273,16 +1339,41 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
                self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
        }
 
-       /// Gets the list of pending events which were generated by previous actions, clearing the list
-       /// in the process.
+       /// Processes [`SpendableOutputs`] events produced from each [`ChannelMonitor`] upon maturity.
+       ///
+       /// For channels featuring anchor outputs, this method will also process [`BumpTransaction`]
+       /// events produced from each [`ChannelMonitor`] while there is a balance to claim onchain
+       /// within each channel. As the confirmation of a commitment transaction may be critical to the
+       /// safety of funds, we recommend invoking this every 30 seconds, or lower if running in an
+       /// environment with spotty connections, like on mobile.
        ///
-       /// This is called by the [`EventsProvider::process_pending_events`] implementation for
-       /// [`ChainMonitor`].
+       /// An [`EventHandler`] may safely call back to the provider, though this shouldn't be needed in
+       /// order to handle these events.
        ///
-       /// [`EventsProvider::process_pending_events`]: crate::events::EventsProvider::process_pending_events
-       /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
+       /// [`SpendableOutputs`]: crate::events::Event::SpendableOutputs
+       /// [`BumpTransaction`]: crate::events::Event::BumpTransaction
+       pub fn process_pending_events<H: Deref>(&self, handler: &H) where H::Target: EventHandler {
+               let mut ev;
+               process_events_body!(Some(self), ev, handler.handle_event(ev));
+       }
+
+       /// Processes any events asynchronously.
+       ///
+       /// See [`Self::process_pending_events`] for more information.
+       pub async fn process_pending_events_async<Future: core::future::Future, H: Fn(Event) -> Future>(
+               &self, handler: &H
+       ) {
+               let mut ev;
+               process_events_body!(Some(self), ev, { handler(ev).await });
+       }
+
+       #[cfg(test)]
        pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
-               self.inner.lock().unwrap().get_and_clear_pending_events()
+               let mut ret = Vec::new();
+               let mut lck = self.inner.lock().unwrap();
+               mem::swap(&mut ret, &mut lck.pending_events);
+               ret.append(&mut lck.get_repeated_events());
+               ret
        }
 
        pub(crate) fn get_min_seen_secret(&self) -> u64 {
@@ -1472,6 +1563,27 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
        pub fn current_best_block(&self) -> BestBlock {
                self.inner.lock().unwrap().best_block.clone()
        }
+
+       /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
+       /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
+       /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
+       /// invoking this every 30 seconds, or lower if running in an environment with spotty
+       /// connections, like on mobile.
+       pub fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
+               &self, broadcaster: B, fee_estimator: F, logger: L,
+       )
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               let fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
+               let mut inner = self.inner.lock().unwrap();
+               let current_height = inner.best_block.height;
+               inner.onchain_tx_handler.rebroadcast_pending_claims(
+                       current_height, &broadcaster, &fee_estimator, &logger,
+               );
+       }
 }
 
 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
@@ -1542,7 +1654,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                        debug_assert!(htlc_input_idx_opt.is_some());
                                        BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
                                } else {
-                                       debug_assert!(!self.onchain_tx_handler.opt_anchors());
+                                       debug_assert!(!self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx());
                                        BitcoinOutPoint::new(*txid, 0)
                                }
                        } else {
@@ -1607,9 +1719,10 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                return Some(Balance::MaybeTimeoutClaimableHTLC {
                                        claimable_amount_satoshis: htlc.amount_msat / 1000,
                                        claimable_height: htlc.cltv_expiry,
+                                       payment_hash: htlc.payment_hash,
                                });
                        }
-               } else if self.payment_preimages.get(&htlc.payment_hash).is_some() {
+               } else if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
                        // Otherwise (the payment was inbound), only expose it as claimable if
                        // we know the preimage.
                        // Note that if there is a pending claim, but it did not use the
@@ -1625,12 +1738,15 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                return Some(Balance::ContentiousClaimable {
                                        claimable_amount_satoshis: htlc.amount_msat / 1000,
                                        timeout_height: htlc.cltv_expiry,
+                                       payment_hash: htlc.payment_hash,
+                                       payment_preimage: *payment_preimage,
                                });
                        }
                } else if htlc_resolved.is_none() {
                        return Some(Balance::MaybePreimageClaimableHTLC {
                                claimable_amount_satoshis: htlc.amount_msat / 1000,
                                expiry_height: htlc.cltv_expiry,
+                               payment_hash: htlc.payment_hash,
                        });
                }
                None
@@ -1792,6 +1908,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
                                        res.push(Balance::MaybeTimeoutClaimableHTLC {
                                                claimable_amount_satoshis: htlc.amount_msat / 1000,
                                                claimable_height: htlc.cltv_expiry,
+                                               payment_hash: htlc.payment_hash,
                                        });
                                } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
                                        claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
@@ -1801,6 +1918,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
                                        res.push(Balance::MaybePreimageClaimableHTLC {
                                                claimable_amount_satoshis: htlc.amount_msat / 1000,
                                                expiry_height: htlc.cltv_expiry,
+                                               payment_hash: htlc.payment_hash,
                                        });
                                }
                        }
@@ -2160,7 +2278,53 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
        /// is important that any clones of this channel monitor (including remote clones) by kept
        /// up-to-date as our holder commitment transaction is updated.
        /// Panics if set_on_holder_tx_csv has never been called.
-       fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)]) -> Result<(), &'static str> {
+       fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, mut htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)], nondust_htlc_sources: Vec<HTLCSource>) -> Result<(), &'static str> {
+               if htlc_outputs.iter().any(|(_, s, _)| s.is_some()) {
+                       // If we have non-dust HTLCs in htlc_outputs, ensure they match the HTLCs in the
+                       // `holder_commitment_tx`. In the future, we'll no longer provide the redundant data
+                       // and just pass in source data via `nondust_htlc_sources`.
+                       debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.trust().htlcs().len());
+                       for (a, b) in htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).map(|(h, _, _)| h).zip(holder_commitment_tx.trust().htlcs().iter()) {
+                               debug_assert_eq!(a, b);
+                       }
+                       debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.counterparty_htlc_sigs.len());
+                       for (a, b) in htlc_outputs.iter().filter_map(|(_, s, _)| s.as_ref()).zip(holder_commitment_tx.counterparty_htlc_sigs.iter()) {
+                               debug_assert_eq!(a, b);
+                       }
+                       debug_assert!(nondust_htlc_sources.is_empty());
+               } else {
+                       // If we don't have any non-dust HTLCs in htlc_outputs, assume they were all passed via
+                       // `nondust_htlc_sources`, building up the final htlc_outputs by combining
+                       // `nondust_htlc_sources` and the `holder_commitment_tx`
+                       #[cfg(debug_assertions)] {
+                               let mut prev = -1;
+                               for htlc in holder_commitment_tx.trust().htlcs().iter() {
+                                       assert!(htlc.transaction_output_index.unwrap() as i32 > prev);
+                                       prev = htlc.transaction_output_index.unwrap() as i32;
+                               }
+                       }
+                       debug_assert!(htlc_outputs.iter().all(|(htlc, _, _)| htlc.transaction_output_index.is_none()));
+                       debug_assert!(htlc_outputs.iter().all(|(_, sig_opt, _)| sig_opt.is_none()));
+                       debug_assert_eq!(holder_commitment_tx.trust().htlcs().len(), holder_commitment_tx.counterparty_htlc_sigs.len());
+
+                       let mut sources_iter = nondust_htlc_sources.into_iter();
+
+                       for (htlc, counterparty_sig) in holder_commitment_tx.trust().htlcs().iter()
+                               .zip(holder_commitment_tx.counterparty_htlc_sigs.iter())
+                       {
+                               if htlc.offered {
+                                       let source = sources_iter.next().expect("Non-dust HTLC sources didn't match commitment tx");
+                                       #[cfg(debug_assertions)] {
+                                               assert!(source.possibly_matches_output(htlc));
+                                       }
+                                       htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), Some(source)));
+                               } else {
+                                       htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), None));
+                               }
+                       }
+                       debug_assert!(sources_iter.next().is_none());
+               }
+
                let trusted_tx = holder_commitment_tx.trust();
                let txid = trusted_tx.txid();
                let tx_keys = trusted_tx.keys();
@@ -2251,10 +2415,13 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                where B::Target: BroadcasterInterface,
                                        L::Target: Logger,
        {
-               for tx in self.get_latest_holder_commitment_txn(logger).iter() {
+               let commit_txs = self.get_latest_holder_commitment_txn(logger);
+               let mut txs = vec![];
+               for tx in commit_txs.iter() {
                        log_info!(logger, "Broadcasting local {}", log_tx!(tx));
-                       broadcaster.broadcast_transaction(tx);
+                       txs.push(tx);
                }
+               broadcaster.broadcast_transactions(&txs);
                self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
        }
 
@@ -2263,16 +2430,32 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                F::Target: FeeEstimator,
                L::Target: Logger,
        {
-               log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
-                       log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
-               // 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 self.latest_update_id == CLOSED_CHANNEL_UPDATE_ID && updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
+                       log_info!(logger, "Applying post-force-closed update to monitor {} with {} change(s).",
+                               log_funding_info!(self), updates.updates.len());
+               } else if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
+                       log_info!(logger, "Applying force close update to monitor {} with {} change(s).",
+                               log_funding_info!(self), updates.updates.len());
+               } else {
+                       log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} change(s).",
+                               log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
+               }
+               // 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.
+               //
+               // The `ChannelManager` may also queue redundant `ChannelForceClosed` updates if it still
+               // thinks the channel needs to have its commitment transaction broadcast, so we'll allow
+               // them as well.
                if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
                        assert_eq!(updates.updates.len(), 1);
                        match updates.updates[0] {
-                               ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
+                               ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
+                               // We should have already seen a `ChannelForceClosed` update if we're trying to
+                               // provide a preimage at this point.
+                               ChannelMonitorUpdateStep::PaymentPreimage { .. } =>
+                                       debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID),
                                _ => {
                                        log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
                                        panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
@@ -2285,10 +2468,10 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
                for update in updates.updates.iter() {
                        match update {
-                               ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs } => {
+                               ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs, nondust_htlc_sources } => {
                                        log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
                                        if self.lockdown_from_offchain { panic!(); }
-                                       if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs) {
+                                       if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs, nondust_htlc_sources.clone()) {
                                                log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
                                                log_error!(logger, "    {}", e);
                                                ret = Err(());
@@ -2323,22 +2506,23 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                                                _ => false,
                                                        }).is_some();
                                                if detected_funding_spend {
+                                                       log_trace!(logger, "Avoiding commitment broadcast, already detected confirmed spend onchain");
                                                        continue;
                                                }
                                                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() {
+                                               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                                                        let funding_output = HolderFundingOutput::build(
                                                                self.funding_redeemscript.clone(), self.channel_value_satoshis,
-                                                               self.onchain_tx_handler.opt_anchors(),
+                                                               self.onchain_tx_handler.channel_type_features().clone(),
                                                        );
                                                        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,
+                                                               best_block_height, best_block_height
                                                        );
                                                        self.onchain_tx_handler.update_claims_view_from_requests(
                                                                vec![commitment_package], best_block_height, best_block_height,
@@ -2364,9 +2548,18 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                },
                        }
                }
+
+               // If the updates succeeded and we were in an already closed channel state, then there's no
+               // need to refuse any updates we expect to receive afer seeing a confirmed commitment.
+               if ret.is_ok() && updates.update_id == CLOSED_CHANNEL_UPDATE_ID && self.latest_update_id == updates.update_id {
+                       return Ok(());
+               }
+
                self.latest_update_id = updates.update_id;
 
-               if ret.is_ok() && self.funding_spend_seen {
+               // Refuse updates after we've detected a spend onchain, but only if we haven't processed a
+               // force closed monitor update yet.
+               if ret.is_ok() && self.funding_spend_seen && self.latest_update_id != CLOSED_CHANNEL_UPDATE_ID {
                        log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
                        Err(())
                } else { ret }
@@ -2396,11 +2589,13 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                ret
        }
 
-       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(..) {
+       /// Gets the set of events that are repeated regularly (e.g. those which RBF bump
+       /// transactions). We're okay if we lose these on restart as they'll be regenerated for us at
+       /// some regular interval via [`ChannelMonitor::rebroadcast_pending_claims`].
+       pub(super) fn get_repeated_events(&mut self) -> Vec<Event> {
+               let pending_claim_events = self.onchain_tx_handler.get_and_clear_pending_claim_events();
+               let mut ret = Vec::with_capacity(pending_claim_events.len());
+               for (claim_id, claim_event) in pending_claim_events {
                        match claim_event {
                                ClaimEvent::BumpCommitment {
                                        package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
@@ -2411,12 +2606,16 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                        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 {
+                                               claim_id,
                                                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,
+                                                       channel_derivation_parameters: ChannelDerivationParameters {
+                                                               keys_id: self.channel_keys_id,
+                                                               value_satoshis: self.channel_value_satoshis,
+                                                               transaction_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
+                                                       },
                                                        outpoint: BitcoinOutPoint {
                                                                txid: commitment_txid,
                                                                vout: anchor_output_idx,
@@ -2426,24 +2625,31 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                        }));
                                },
                                ClaimEvent::BumpHTLC {
-                                       target_feerate_sat_per_1000_weight, htlcs,
+                                       target_feerate_sat_per_1000_weight, htlcs, tx_lock_time,
                                } => {
                                        let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
                                        for htlc in htlcs {
                                                htlc_descriptors.push(HTLCDescriptor {
-                                                       channel_keys_id: self.channel_keys_id,
-                                                       channel_value_satoshis: self.channel_value_satoshis,
-                                                       channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
+                                                       channel_derivation_parameters: ChannelDerivationParameters {
+                                                               keys_id: self.channel_keys_id,
+                                                               value_satoshis: self.channel_value_satoshis,
+                                                               transaction_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
+                                                       },
                                                        commitment_txid: htlc.commitment_txid,
                                                        per_commitment_number: htlc.per_commitment_number,
+                                                       per_commitment_point: self.onchain_tx_handler.signer.get_per_commitment_point(
+                                                               htlc.per_commitment_number, &self.onchain_tx_handler.secp_ctx,
+                                                       ),
                                                        htlc: htlc.htlc,
                                                        preimage: htlc.preimage,
                                                        counterparty_sig: htlc.counterparty_sig,
                                                });
                                        }
                                        ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
+                                               claim_id,
                                                target_feerate_sat_per_1000_weight,
                                                htlc_descriptors,
+                                               tx_lock_time,
                                        }));
                                }
                        }
@@ -2511,8 +2717,8 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                        // First, process non-htlc outputs (to_holder & to_counterparty)
                        for (idx, outp) in tx.output.iter().enumerate() {
                                if outp.script_pubkey == revokeable_p2wsh {
-                                       let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_commitment_params.on_counterparty_tx_csv);
-                                       let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height);
+                                       let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_commitment_params.on_counterparty_tx_csv, self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx());
+                                       let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height);
                                        claimable_outpoints.push(justice_package);
                                        to_counterparty_output_info =
                                                Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
@@ -2529,8 +2735,8 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                                        return (claimable_outpoints, (commitment_txid, watch_outputs),
                                                                to_counterparty_output_info);
                                                }
-                                               let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_some());
-                                               let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
+                                               let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), &self.onchain_tx_handler.channel_transaction_parameters.channel_type_features);
+                                               let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, height);
                                                claimable_outpoints.push(justice_package);
                                        }
                                }
@@ -2647,16 +2853,15 @@ impl<Signer: WriteableEcdsaChannelSigner> 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(), self.onchain_tx_handler.opt_anchors()))
+                                                               preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.channel_type_features().clone()))
                                        } 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(), self.onchain_tx_handler.opt_anchors()))
+                                                               htlc.clone(), self.onchain_tx_handler.channel_type_features().clone()))
                                        };
-                                       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);
+                                       let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry, 0);
                                        claimable_outpoints.push(counterparty_package);
                                }
                        }
@@ -2695,11 +2900,12 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                let revk_outp = RevokedOutput::build(
                                        per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
                                        self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
-                                       tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
+                                       tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv,
+                                       false
                                );
                                let justice_package = PackageTemplate::build_package(
                                        htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
-                                       height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
+                                       height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height
                                );
                                claimable_outpoints.push(justice_package);
                                if outputs_to_watch.is_none() {
@@ -2722,11 +2928,11 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 
                for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
                        if let Some(transaction_output_index) = htlc.transaction_output_index {
-                               let (htlc_output, aggregable) = if htlc.offered {
+                               let htlc_output = if htlc.offered {
                                        let htlc_output = HolderHTLCOutput::build_offered(
-                                               htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
+                                               htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.channel_type_features().clone()
                                        );
-                                       (htlc_output, false)
+                                       htlc_output
                                } else {
                                        let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
                                                preimage.clone()
@@ -2735,14 +2941,14 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                                                continue;
                                        };
                                        let htlc_output = HolderHTLCOutput::build_accepted(
-                                               payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
+                                               payment_preimage, htlc.amount_msat, self.onchain_tx_handler.channel_type_features().clone()
                                        );
-                                       (htlc_output, self.onchain_tx_handler.opt_anchors())
+                                       htlc_output
                                };
                                let htlc_package = PackageTemplate::build_package(
                                        holder_tx.txid, transaction_output_index,
                                        PackageSolvingData::HolderHTLCOutput(htlc_output),
-                                       htlc.cltv_expiry, aggregable, conf_height
+                                       htlc.cltv_expiry, conf_height
                                );
                                claim_requests.push(htlc_package);
                        }
@@ -2819,7 +3025,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                let mut holder_transactions = vec![commitment_tx];
                // When anchor outputs are present, the HTLC transactions are only valid once the commitment
                // transaction confirms.
-               if self.onchain_tx_handler.opt_anchors() {
+               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                        return holder_transactions;
                }
                for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
@@ -2857,7 +3063,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                let mut holder_transactions = vec![commitment_tx];
                // When anchor outputs are present, the HTLC transactions are only final once the commitment
                // transaction confirms due to the CSV 1 encumberance.
-               if self.onchain_tx_handler.opt_anchors() {
+               if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                        return holder_transactions;
                }
                for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
@@ -3081,8 +3287,8 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 
                let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
                if should_broadcast {
-                       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());
+                       let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.channel_type_features().clone());
+                       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(), 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);
@@ -3090,7 +3296,7 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
                        // 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() {
+                       if !self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
                                // 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.
@@ -3668,8 +3874,9 @@ where
        }
 }
 
-impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
+impl<Signer: WriteableEcdsaChannelSigner, M, T: Deref, F: Deref, L: Deref> chain::Confirm for (M, T, F, L)
 where
+       M: Deref<Target = ChannelMonitor<Signer>>,
        T::Target: BroadcasterInterface,
        F::Target: FeeEstimator,
        L::Target: Logger,
@@ -3913,12 +4120,12 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP
                let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
                read_tlv_fields!(reader, {
                        (1, funding_spend_confirmed, option),
-                       (3, htlcs_resolved_on_chain, vec_type),
-                       (5, pending_monitor_events, vec_type),
+                       (3, htlcs_resolved_on_chain, optional_vec),
+                       (5, pending_monitor_events, optional_vec),
                        (7, funding_spend_seen, option),
                        (9, counterparty_node_id, option),
                        (11, confirmed_commitment_tx_counterparty_output, option),
-                       (13, spendable_txids_confirmed, vec_type),
+                       (13, spendable_txids_confirmed, optional_vec),
                        (15, counterparty_fulfilled_htlcs, option),
                });
 
@@ -3958,6 +4165,7 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP
                        payment_preimages,
                        pending_monitor_events: pending_monitor_events.unwrap(),
                        pending_events,
+                       is_processing_pending_events: false,
 
                        onchain_events_awaiting_threshold_conf,
                        outputs_to_watch,
@@ -3980,7 +4188,6 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP
 
 #[cfg(test)]
 mod tests {
-       use bitcoin::blockdata::block::BlockHeader;
        use bitcoin::blockdata::script::{Script, Builder};
        use bitcoin::blockdata::opcodes;
        use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
@@ -4004,12 +4211,12 @@ mod tests {
        use crate::chain::channelmonitor::ChannelMonitor;
        use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
        use crate::chain::transaction::OutPoint;
-       use crate::chain::keysinterface::InMemorySigner;
+       use crate::sign::InMemorySigner;
        use crate::events::ClosureReason;
        use crate::ln::{PaymentPreimage, PaymentHash};
        use crate::ln::chan_utils;
        use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
-       use crate::ln::channelmanager::{PaymentSendFailure, PaymentId};
+       use crate::ln::channelmanager::{PaymentSendFailure, PaymentId, RecipientOnionFields};
        use crate::ln::functional_test_utils::*;
        use crate::ln::script::ShutdownScript;
        use crate::util::errors::APIError;
@@ -4017,7 +4224,8 @@ mod tests {
        use crate::util::ser::{ReadableArgs, Writeable};
        use crate::sync::{Arc, Mutex};
        use crate::io;
-       use bitcoin::{PackedLockTime, Sequence, TxMerkleNode, Witness};
+       use bitcoin::{PackedLockTime, Sequence, Witness};
+       use crate::ln::features::ChannelTypeFeatures;
        use crate::prelude::*;
 
        fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
@@ -4056,10 +4264,7 @@ mod tests {
 
                // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
                // channel is now closed, but the ChannelManager doesn't know that yet.
-               let new_header = BlockHeader {
-                       version: 2, time: 0, bits: 0, nonce: 0,
-                       prev_blockhash: nodes[0].best_block_info().0,
-                       merkle_root: TxMerkleNode::all_zeros() };
+               let new_header = create_dummy_header(nodes[0].best_block_info().0, 0);
                let conf_height = nodes[0].best_block_info().1 + 1;
                nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
                        &[(0, broadcast_tx)], conf_height);
@@ -4071,8 +4276,9 @@ mod tests {
                // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
                // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
                let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
-               unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
-                       true, APIError::ChannelUnavailable { ref err },
+               unwrap_send_err!(nodes[1].node.send_payment_with_route(&route, payment_hash,
+                               RecipientOnionFields::secret_only(payment_secret), PaymentId(payment_hash.0)
+                       ), true, APIError::ChannelUnavailable { ref err },
                        assert!(err.contains("ChannelMonitor storage failure")));
                check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
                check_closed_broadcast!(nodes[1], true);
@@ -4089,7 +4295,7 @@ mod tests {
                replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
                replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
 
-               let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
+               let broadcaster = TestBroadcaster::with_blocks(Arc::clone(&nodes[1].blocks));
                assert!(
                        pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
                        .is_err());
@@ -4115,10 +4321,7 @@ mod tests {
        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()),
-                       blocks: Arc::new(Mutex::new(Vec::new()))
-               });
+               let broadcaster = Arc::new(TestBroadcaster::new(Network::Testnet));
                let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
 
                let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
@@ -4132,7 +4335,7 @@ mod tests {
                        }
                }
 
-               macro_rules! preimages_slice_to_htlc_outputs {
+               macro_rules! preimages_slice_to_htlcs {
                        ($preimages_slice: expr) => {
                                {
                                        let mut res = Vec::new();
@@ -4143,21 +4346,20 @@ mod tests {
                                                        cltv_expiry: 0,
                                                        payment_hash: preimage.1.clone(),
                                                        transaction_output_index: Some(idx as u32),
-                                               }, None));
+                                               }, ()));
                                        }
                                        res
                                }
                        }
                }
-               macro_rules! preimages_to_holder_htlcs {
+               macro_rules! preimages_slice_to_htlc_outputs {
                        ($preimages_slice: expr) => {
-                               {
-                                       let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
-                                       let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
-                                       res
-                               }
+                               preimages_slice_to_htlcs!($preimages_slice).into_iter().map(|(htlc, _)| (htlc, None)).collect()
                        }
                }
+               let dummy_sig = crate::util::crypto::sign(&secp_ctx,
+                       &bitcoin::secp256k1::Message::from_slice(&[42; 32]).unwrap(),
+                       &SecretKey::from_slice(&[42; 32]).unwrap());
 
                macro_rules! test_preimages_exist {
                        ($preimages_slice: expr, $monitor: expr) => {
@@ -4177,6 +4379,7 @@ mod tests {
                        [41; 32],
                        0,
                        [0; 32],
+                       [0; 32],
                );
 
                let counterparty_pubkeys = ChannelPublicKeys {
@@ -4196,21 +4399,22 @@ mod tests {
                                selected_contest_delay: 67,
                        }),
                        funding_outpoint: Some(funding_outpoint),
-                       opt_anchors: None,
-                       opt_non_zero_fee_anchors: None,
+                       channel_type_features: ChannelTypeFeatures::only_static_remote_key()
                };
                // Prune with one old state and a holder commitment tx holding a few overlaps with the
                // old state.
                let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let best_block = BestBlock::from_network(Network::Testnet);
                let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
-                                                 Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
-                                                 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
-                                                 &channel_parameters,
-                                                 Script::new(), 46, 0,
-                                                 HolderCommitmentTransaction::dummy(), best_block, dummy_key);
-
-               monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
+                       Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
+                       (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
+                       &channel_parameters, Script::new(), 46, 0, HolderCommitmentTransaction::dummy(&mut Vec::new()),
+                       best_block, dummy_key);
+
+               let mut htlcs = preimages_slice_to_htlcs!(preimages[0..10]);
+               let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
+               monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
+                       htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
                monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
                        preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
                monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
@@ -4243,7 +4447,10 @@ mod tests {
 
                // Now update holder commitment tx info, pruning only element 18 as we still care about the
                // previous commitment tx's preimages too
-               monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
+               let mut htlcs = preimages_slice_to_htlcs!(preimages[0..5]);
+               let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
+               monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
+                       htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                monitor.provide_secret(281474976710653, secret.clone()).unwrap();
                assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
@@ -4251,7 +4458,10 @@ mod tests {
                test_preimages_exist!(&preimages[18..20], monitor);
 
                // But if we do it again, we'll prune 5-10
-               monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
+               let mut htlcs = preimages_slice_to_htlcs!(preimages[0..3]);
+               let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
+               monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx,
+                       htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                monitor.provide_secret(281474976710652, secret.clone()).unwrap();
                assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
@@ -4305,7 +4515,7 @@ mod tests {
                let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
 
                // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
-               for &opt_anchors in [false, true].iter() {
+               for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
                        let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
                        let mut sum_actual_sigs = 0;
                        for i in 0..4 {
@@ -4324,12 +4534,12 @@ mod tests {
                                value: 0,
                        });
                        let base_weight = claim_tx.weight();
-                       let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(opt_anchors), weight_revoked_offered_htlc(opt_anchors), weight_revoked_received_htlc(opt_anchors)];
+                       let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(channel_type_features), weight_revoked_offered_htlc(channel_type_features), weight_revoked_received_htlc(channel_type_features)];
                        let mut inputs_total_weight = 2; // count segwit flags
                        {
                                let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
                                for (idx, inp) in inputs_weight.iter().enumerate() {
-                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
                                        inputs_total_weight += inp;
                                }
                        }
@@ -4337,7 +4547,7 @@ mod tests {
                }
 
                // Claim tx with 1 offered HTLCs, 3 received HTLCs
-               for &opt_anchors in [false, true].iter() {
+               for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
                        let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
                        let mut sum_actual_sigs = 0;
                        for i in 0..4 {
@@ -4356,12 +4566,12 @@ mod tests {
                                value: 0,
                        });
                        let base_weight = claim_tx.weight();
-                       let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
+                       let inputs_weight = vec![weight_offered_htlc(channel_type_features), weight_received_htlc(channel_type_features), weight_received_htlc(channel_type_features), weight_received_htlc(channel_type_features)];
                        let mut inputs_total_weight = 2; // count segwit flags
                        {
                                let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
                                for (idx, inp) in inputs_weight.iter().enumerate() {
-                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
                                        inputs_total_weight += inp;
                                }
                        }
@@ -4369,7 +4579,7 @@ mod tests {
                }
 
                // Justice tx with 1 revoked HTLC-Success tx output
-               for &opt_anchors in [false, true].iter() {
+               for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
                        let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
                        let mut sum_actual_sigs = 0;
                        claim_tx.input.push(TxIn {
@@ -4391,7 +4601,7 @@ mod tests {
                        {
                                let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
                                for (idx, inp) in inputs_weight.iter().enumerate() {
-                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
+                                       sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
                                        inputs_total_weight += inp;
                                }
                        }