Merge pull request #2370 from valentinewallace/2023-06-send-along-path-args
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 398975c6565c1968778b4de5948e1109c301f886..c7fc70a4593d66601b7d0d0e2acf8759196e5ffd 100644 (file)
@@ -40,12 +40,12 @@ use crate::events::{Event, EventHandler, EventsProvider, MessageSendEvent, Messa
 // Since this struct is returned in `list_channels` methods, expose it here in case users want to
 // construct one themselves.
 use crate::ln::{inbound_payment, PaymentHash, PaymentPreimage, PaymentSecret};
-use crate::ln::channel::{Channel, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel};
+use crate::ln::channel::{Channel, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UnfundedChannelContext, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel};
 use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
 #[cfg(any(feature = "_test_utils", test))]
-use crate::ln::features::InvoiceFeatures;
+use crate::ln::features::Bolt11InvoiceFeatures;
 use crate::routing::gossip::NetworkGraph;
-use crate::routing::router::{BlindedTail, DefaultRouter, InFlightHtlcs, Path, Payee, PaymentParameters, Route, RouteHop, RouteParameters, Router};
+use crate::routing::router::{BlindedTail, DefaultRouter, InFlightHtlcs, Path, Payee, PaymentParameters, Route, RouteParameters, Router};
 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
 use crate::ln::msgs;
 use crate::ln::onion_utils;
@@ -53,7 +53,7 @@ use crate::ln::onion_utils::HTLCFailReason;
 use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
 #[cfg(test)]
 use crate::ln::outbound_payment;
-use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment};
+use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs};
 use crate::ln::wire::Encode;
 use crate::sign::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, ChannelSigner, WriteableEcdsaChannelSigner};
 use crate::util::config::{UserConfig, ChannelConfig, ChannelConfigUpdate};
@@ -530,6 +530,13 @@ enum BackgroundEvent {
                funding_txo: OutPoint,
                update: ChannelMonitorUpdate
        },
+       /// Some [`ChannelMonitorUpdate`] (s) completed before we were serialized but we still have
+       /// them marked pending, thus we need to run any [`MonitorUpdateCompletionAction`] (s) pending
+       /// on a channel.
+       MonitorUpdatesComplete {
+               counterparty_node_id: PublicKey,
+               channel_id: [u8; 32],
+       },
 }
 
 #[derive(Debug)]
@@ -678,7 +685,7 @@ impl <Signer: ChannelSigner> PeerState<Signer> {
                        && self.in_flight_monitor_updates.is_empty()
        }
 
-       // Returns a count of all channels we have with this peer, including pending channels.
+       // Returns a count of all channels we have with this peer, including unfunded channels.
        fn total_channel_count(&self) -> usize {
                self.channel_by_id.len() +
                        self.outbound_v1_channel_by_id.len() +
@@ -752,7 +759,23 @@ pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<
 /// of [`KeysManager`] and [`DefaultRouter`].
 ///
 /// This is not exported to bindings users as Arcs don't make sense in bindings
-pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> = ChannelManager<&'a M, &'b T, &'c KeysManager, &'c KeysManager, &'c KeysManager, &'d F, &'e DefaultRouter<&'f NetworkGraph<&'g L>, &'g L, &'h Mutex<ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>>, ProbabilisticScoringFeeParameters, ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>>, &'g L>;
+pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> =
+       ChannelManager<
+               &'a M,
+               &'b T,
+               &'c KeysManager,
+               &'c KeysManager,
+               &'c KeysManager,
+               &'d F,
+               &'e DefaultRouter<
+                       &'f NetworkGraph<&'g L>,
+                       &'g L,
+                       &'h Mutex<ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>>,
+                       ProbabilisticScoringFeeParameters,
+                       ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>
+               >,
+               &'g L
+       >;
 
 macro_rules! define_test_pub_trait { ($vis: vis) => {
 /// A trivial trait which describes any [`ChannelManager`] used in testing.
@@ -1463,6 +1486,9 @@ pub struct ChannelDetails {
        ///
        /// [`confirmations_required`]: ChannelDetails::confirmations_required
        pub is_channel_ready: bool,
+       /// The stage of the channel's shutdown.
+       /// `None` for `ChannelDetails` serialized on LDK versions prior to 0.0.116.
+       pub channel_shutdown_state: Option<ChannelShutdownState>,
        /// True if the channel is (a) confirmed and channel_ready messages have been exchanged, (b)
        /// the peer is connected, and (c) the channel is not currently negotiating a shutdown.
        ///
@@ -1502,10 +1528,13 @@ impl ChannelDetails {
                self.short_channel_id.or(self.outbound_scid_alias)
        }
 
-       fn from_channel_context<Signer: WriteableEcdsaChannelSigner>(context: &ChannelContext<Signer>,
-               best_block_height: u32, latest_features: InitFeatures) -> Self {
-
-               let balance = context.get_available_balances();
+       fn from_channel_context<Signer: WriteableEcdsaChannelSigner, F: Deref>(
+               context: &ChannelContext<Signer>, best_block_height: u32, latest_features: InitFeatures,
+               fee_estimator: &LowerBoundedFeeEstimator<F>
+       ) -> Self
+       where F::Target: FeeEstimator
+       {
+               let balance = context.get_available_balances(fee_estimator);
                let (to_remote_reserve_satoshis, to_self_reserve_satoshis) =
                        context.get_holder_counterparty_selected_channel_reserve_satoshis();
                ChannelDetails {
@@ -1550,10 +1579,33 @@ impl ChannelDetails {
                        inbound_htlc_minimum_msat: Some(context.get_holder_htlc_minimum_msat()),
                        inbound_htlc_maximum_msat: context.get_holder_htlc_maximum_msat(),
                        config: Some(context.config()),
+                       channel_shutdown_state: Some(context.shutdown_state()),
                }
        }
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+/// Further information on the details of the channel shutdown.
+/// Upon channels being forced closed (i.e. commitment transaction confirmation detected
+/// by `ChainMonitor`), ChannelShutdownState will be set to `ShutdownComplete` or
+/// the channel will be removed shortly.
+/// Also note, that in normal operation, peers could disconnect at any of these states
+/// and require peer re-connection before making progress onto other states
+pub enum ChannelShutdownState {
+       /// Channel has not sent or received a shutdown message.
+       NotShuttingDown,
+       /// Local node has sent a shutdown message for this channel.
+       ShutdownInitiated,
+       /// Shutdown message exchanges have concluded and the channels are in the midst of
+       /// resolving all existing open HTLCs before closing can continue.
+       ResolvingHTLCs,
+       /// All HTLCs have been resolved, nodes are currently negotiating channel close onchain fee rates.
+       NegotiatingClosingFee,
+       /// We've successfully negotiated a closing_signed dance. At this point `ChannelManager` is about
+       /// to drop the channel.
+       ShutdownComplete,
+}
+
 /// Used by [`ChannelManager::list_recent_payments`] to express the status of recent payments.
 /// These include payments that have yet to find a successful path, or have unresolved HTLCs.
 #[derive(Debug, PartialEq)]
@@ -1697,12 +1749,12 @@ macro_rules! convert_chan_err {
                        },
                }
        };
-       ($self: ident, $err: expr, $channel_context: expr, $channel_id: expr, PREFUNDED) => {
+       ($self: ident, $err: expr, $channel_context: expr, $channel_id: expr, UNFUNDED) => {
                match $err {
-                       // We should only ever have `ChannelError::Close` when prefunded channels error.
+                       // We should only ever have `ChannelError::Close` when unfunded channels error.
                        // In any case, just close the channel.
                        ChannelError::Warn(msg) | ChannelError::Ignore(msg) | ChannelError::Close(msg) => {
-                               log_error!($self.logger, "Closing prefunded channel {} due to an error: {}", log_bytes!($channel_id[..]), msg);
+                               log_error!($self.logger, "Closing unfunded channel {} due to an error: {}", log_bytes!($channel_id[..]), msg);
                                update_maps_on_chan_removal!($self, &$channel_context);
                                let shutdown_res = $channel_context.force_shutdown(false);
                                (true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, $channel_context.get_user_id(),
@@ -1732,7 +1784,7 @@ macro_rules! try_v1_outbound_chan_entry {
                match $res {
                        Ok(res) => res,
                        Err(e) => {
-                               let (drop, res) = convert_chan_err!($self, e, $entry.get_mut().context, $entry.key(), PREFUNDED);
+                               let (drop, res) = convert_chan_err!($self, e, $entry.get_mut().context, $entry.key(), UNFUNDED);
                                if drop {
                                        $entry.remove_entry();
                                }
@@ -1975,6 +2027,8 @@ macro_rules! process_events_body {
                                let mut pending_events = $self.pending_events.lock().unwrap();
                                pending_events.drain(..num_events);
                                processed_all_events = pending_events.is_empty();
+                               // Note that `push_pending_forwards_ev` relies on `pending_events_processor` being
+                               // updated here with the `pending_events` lock acquired.
                                $self.pending_events_processor.store(false, Ordering::Release);
                        }
 
@@ -2004,6 +2058,8 @@ where
 {
        /// Constructs a new `ChannelManager` to hold several channels and route between them.
        ///
+       /// The current time or latest block header time can be provided as the `current_timestamp`.
+       ///
        /// This is the main "logic hub" for all channel-related actions, and implements
        /// [`ChannelMessageHandler`].
        ///
@@ -2017,7 +2073,11 @@ where
        /// [`block_connected`]: chain::Listen::block_connected
        /// [`block_disconnected`]: chain::Listen::block_disconnected
        /// [`params.best_block.block_hash`]: chain::BestBlock::block_hash
-       pub fn new(fee_est: F, chain_monitor: M, tx_broadcaster: T, router: R, logger: L, entropy_source: ES, node_signer: NS, signer_provider: SP, config: UserConfig, params: ChainParameters) -> Self {
+       pub fn new(
+               fee_est: F, chain_monitor: M, tx_broadcaster: T, router: R, logger: L, entropy_source: ES,
+               node_signer: NS, signer_provider: SP, config: UserConfig, params: ChainParameters,
+               current_timestamp: u32,
+       ) -> Self {
                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
                let inbound_pmt_key_material = node_signer.get_inbound_payment_key_material();
@@ -2049,7 +2109,7 @@ where
 
                        probing_cookie_secret: entropy_source.get_secure_random_bytes(),
 
-                       highest_seen_timestamp: AtomicUsize::new(0),
+                       highest_seen_timestamp: AtomicUsize::new(current_timestamp as usize),
 
                        per_peer_state: FairRwLock::new(HashMap::new()),
 
@@ -2186,9 +2246,10 @@ where
                        for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
                                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                                let peer_state = &mut *peer_state_lock;
+                               // Only `Channels` in the channel_by_id map can be considered funded.
                                for (_channel_id, channel) in peer_state.channel_by_id.iter().filter(f) {
                                        let details = ChannelDetails::from_channel_context(&channel.context, best_block_height,
-                                               peer_state.latest_features.clone());
+                                               peer_state.latest_features.clone(), &self.fee_estimator);
                                        res.push(details);
                                }
                        }
@@ -2214,17 +2275,17 @@ where
                                let peer_state = &mut *peer_state_lock;
                                for (_channel_id, channel) in peer_state.channel_by_id.iter() {
                                        let details = ChannelDetails::from_channel_context(&channel.context, best_block_height,
-                                               peer_state.latest_features.clone());
+                                               peer_state.latest_features.clone(), &self.fee_estimator);
                                        res.push(details);
                                }
                                for (_channel_id, channel) in peer_state.inbound_v1_channel_by_id.iter() {
                                        let details = ChannelDetails::from_channel_context(&channel.context, best_block_height,
-                                               peer_state.latest_features.clone());
+                                               peer_state.latest_features.clone(), &self.fee_estimator);
                                        res.push(details);
                                }
                                for (_channel_id, channel) in peer_state.outbound_v1_channel_by_id.iter() {
                                        let details = ChannelDetails::from_channel_context(&channel.context, best_block_height,
-                                               peer_state.latest_features.clone());
+                                               peer_state.latest_features.clone(), &self.fee_estimator);
                                        res.push(details);
                                }
                        }
@@ -2254,10 +2315,15 @@ where
                        let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                        let peer_state = &mut *peer_state_lock;
                        let features = &peer_state.latest_features;
+                       let chan_context_to_details = |context| {
+                               ChannelDetails::from_channel_context(context, best_block_height, features.clone(), &self.fee_estimator)
+                       };
                        return peer_state.channel_by_id
                                .iter()
-                               .map(|(_, channel)|
-                                       ChannelDetails::from_channel_context(&channel.context, best_block_height, features.clone()))
+                               .map(|(_, channel)| &channel.context)
+                               .chain(peer_state.outbound_v1_channel_by_id.iter().map(|(_, channel)| &channel.context))
+                               .chain(peer_state.inbound_v1_channel_by_id.iter().map(|(_, channel)| &channel.context))
+                               .map(chan_context_to_details)
                                .collect();
                }
                vec![]
@@ -2314,48 +2380,58 @@ where
 
                let mut failed_htlcs: Vec<(HTLCSource, PaymentHash)>;
                let result: Result<(), _> = loop {
-                       let per_peer_state = self.per_peer_state.read().unwrap();
+                       {
+                               let per_peer_state = self.per_peer_state.read().unwrap();
 
-                       let peer_state_mutex = per_peer_state.get(counterparty_node_id)
-                               .ok_or_else(|| APIError::ChannelUnavailable { err: format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id) })?;
+                               let peer_state_mutex = per_peer_state.get(counterparty_node_id)
+                                       .ok_or_else(|| APIError::ChannelUnavailable { err: format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id) })?;
 
-                       let mut peer_state_lock = peer_state_mutex.lock().unwrap();
-                       let peer_state = &mut *peer_state_lock;
-                       match peer_state.channel_by_id.entry(channel_id.clone()) {
-                               hash_map::Entry::Occupied(mut chan_entry) => {
-                                       let funding_txo_opt = chan_entry.get().context.get_funding_txo();
-                                       let their_features = &peer_state.latest_features;
-                                       let (shutdown_msg, mut monitor_update_opt, htlcs) = chan_entry.get_mut()
-                                               .get_shutdown(&self.signer_provider, their_features, target_feerate_sats_per_1000_weight, override_shutdown_script)?;
-                                       failed_htlcs = htlcs;
+                               let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+                               let peer_state = &mut *peer_state_lock;
 
-                                       // We can send the `shutdown` message before updating the `ChannelMonitor`
-                                       // here as we don't need the monitor update to complete until we send a
-                                       // `shutdown_signed`, which we'll delay if we're pending a monitor update.
-                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
-                                               node_id: *counterparty_node_id,
-                                               msg: shutdown_msg,
-                                       });
+                               match peer_state.channel_by_id.entry(channel_id.clone()) {
+                                       hash_map::Entry::Occupied(mut chan_entry) => {
+                                               let funding_txo_opt = chan_entry.get().context.get_funding_txo();
+                                               let their_features = &peer_state.latest_features;
+                                               let (shutdown_msg, mut monitor_update_opt, htlcs) = chan_entry.get_mut()
+                                                       .get_shutdown(&self.signer_provider, their_features, target_feerate_sats_per_1000_weight, override_shutdown_script)?;
+                                               failed_htlcs = htlcs;
 
-                                       // Update the monitor with the shutdown script if necessary.
-                                       if let Some(monitor_update) = monitor_update_opt.take() {
-                                               break handle_new_monitor_update!(self, funding_txo_opt.unwrap(), monitor_update,
-                                                       peer_state_lock, peer_state, per_peer_state, chan_entry).map(|_| ());
-                                       }
+                                               // We can send the `shutdown` message before updating the `ChannelMonitor`
+                                               // here as we don't need the monitor update to complete until we send a
+                                               // `shutdown_signed`, which we'll delay if we're pending a monitor update.
+                                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
+                                                       node_id: *counterparty_node_id,
+                                                       msg: shutdown_msg,
+                                               });
 
-                                       if chan_entry.get().is_shutdown() {
-                                               let channel = remove_channel!(self, chan_entry);
-                                               if let Ok(channel_update) = self.get_channel_update_for_broadcast(&channel) {
-                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
-                                                               msg: channel_update
-                                                       });
+                                               // Update the monitor with the shutdown script if necessary.
+                                               if let Some(monitor_update) = monitor_update_opt.take() {
+                                                       break handle_new_monitor_update!(self, funding_txo_opt.unwrap(), monitor_update,
+                                                               peer_state_lock, peer_state, per_peer_state, chan_entry).map(|_| ());
                                                }
-                                               self.issue_channel_close_events(&channel.context, ClosureReason::HolderForceClosed);
-                                       }
-                                       break Ok(());
-                               },
-                               hash_map::Entry::Vacant(_) => return Err(APIError::ChannelUnavailable{err: format!("Channel with id {} not found for the passed counterparty node_id {}", log_bytes!(*channel_id), counterparty_node_id) })
+
+                                               if chan_entry.get().is_shutdown() {
+                                                       let channel = remove_channel!(self, chan_entry);
+                                                       if let Ok(channel_update) = self.get_channel_update_for_broadcast(&channel) {
+                                                               peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
+                                                                       msg: channel_update
+                                                               });
+                                                       }
+                                                       self.issue_channel_close_events(&channel.context, ClosureReason::HolderForceClosed);
+                                               }
+                                               break Ok(());
+                                       },
+                                       hash_map::Entry::Vacant(_) => (),
+                               }
                        }
+                       // If we reach this point, it means that the channel_id either refers to an unfunded channel or
+                       // it does not exist for this peer. Either way, we can attempt to force-close it.
+                       //
+                       // An appropriate error will be returned for non-existence of the channel if that's the case.
+                       return self.force_close_channel_with_peer(&channel_id, counterparty_node_id, None, false).map(|_| ())
+                       // TODO(dunxen): This is still not ideal as we're doing some extra lookups.
+                       // Fix this with https://github.com/lightningdevkit/rust-lightning/issues/2422
                };
 
                for htlc_source in failed_htlcs.drain(..) {
@@ -2474,14 +2550,14 @@ where
                                self.issue_channel_close_events(&chan.get().context, closure_reason);
                                let mut chan = remove_channel!(self, chan);
                                self.finish_force_close_channel(chan.context.force_shutdown(false));
-                               // Prefunded channel has no update
+                               // Unfunded channel has no update
                                (None, chan.context.get_counterparty_node_id())
                        } else if let hash_map::Entry::Occupied(chan) = peer_state.inbound_v1_channel_by_id.entry(channel_id.clone()) {
                                log_error!(self.logger, "Force-closing channel {}", log_bytes!(channel_id[..]));
                                self.issue_channel_close_events(&chan.get().context, closure_reason);
                                let mut chan = remove_channel!(self, chan);
                                self.finish_force_close_channel(chan.context.force_shutdown(false));
-                               // Prefunded channel has no update
+                               // Unfunded channel has no update
                                (None, chan.context.get_counterparty_node_id())
                        } else {
                                return Err(APIError::ChannelUnavailable{ err: format!("Channel with id {} not found for the passed counterparty node_id {}", log_bytes!(*channel_id), peer_node_id) });
@@ -3021,10 +3097,17 @@ where
        #[cfg(test)]
        pub(crate) fn test_send_payment_along_path(&self, path: &Path, payment_hash: &PaymentHash, recipient_onion: RecipientOnionFields, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
                let _lck = self.total_consistency_lock.read().unwrap();
-               self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv_bytes)
+               self.send_payment_along_path(SendAlongPathArgs {
+                       path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage,
+                       session_priv_bytes
+               })
        }
 
-       fn send_payment_along_path(&self, path: &Path, payment_hash: &PaymentHash, recipient_onion: RecipientOnionFields, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
+       fn send_payment_along_path(&self, args: SendAlongPathArgs) -> Result<(), APIError> {
+               let SendAlongPathArgs {
+                       path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage,
+                       session_priv_bytes
+               } = args;
                // The top-level caller should hold the total_consistency_lock read lock.
                debug_assert!(self.total_consistency_lock.try_write().is_err());
 
@@ -3061,7 +3144,7 @@ where
                                                session_priv: session_priv.clone(),
                                                first_hop_htlc_msat: htlc_msat,
                                                payment_id,
-                                       }, onion_packet, None, &self.logger);
+                                       }, onion_packet, None, &self.fee_estimator, &self.logger);
                                match break_chan_entry!(self, send_res, chan) {
                                        Some(monitor_update) => {
                                                match handle_new_monitor_update!(self, funding_txo, monitor_update, peer_state_lock, peer_state, per_peer_state, chan) {
@@ -3144,6 +3227,7 @@ where
        /// irrevocably committed to on our end. In such a case, do NOT retry the payment with a
        /// different route unless you intend to pay twice!
        ///
+       /// [`RouteHop`]: crate::routing::router::RouteHop
        /// [`Event::PaymentSent`]: events::Event::PaymentSent
        /// [`Event::PaymentFailed`]: events::Event::PaymentFailed
        /// [`UpdateHTLCs`]: events::MessageSendEvent::UpdateHTLCs
@@ -3153,9 +3237,9 @@ where
                let best_block_height = self.best_block.read().unwrap().height();
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments
-                       .send_payment_with_route(route, payment_hash, recipient_onion, payment_id, &self.entropy_source, &self.node_signer, best_block_height,
-                               |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                               self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       .send_payment_with_route(route, payment_hash, recipient_onion, payment_id,
+                               &self.entropy_source, &self.node_signer, best_block_height,
+                               |args| self.send_payment_along_path(args))
        }
 
        /// Similar to [`ChannelManager::send_payment_with_route`], but will automatically find a route based on
@@ -3167,18 +3251,16 @@ where
                        .send_payment(payment_hash, recipient_onion, payment_id, retry_strategy, route_params,
                                &self.router, self.list_usable_channels(), || self.compute_inflight_htlcs(),
                                &self.entropy_source, &self.node_signer, best_block_height, &self.logger,
-                               &self.pending_events,
-                               |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                               self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                               &self.pending_events, |args| self.send_payment_along_path(args))
        }
 
        #[cfg(test)]
        pub(super) fn test_send_payment_internal(&self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>, onion_session_privs: Vec<[u8; 32]>) -> Result<(), PaymentSendFailure> {
                let best_block_height = self.best_block.read().unwrap().height();
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               self.pending_outbound_payments.test_send_payment_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id, recv_value_msat, onion_session_privs, &self.node_signer, best_block_height,
-                       |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+               self.pending_outbound_payments.test_send_payment_internal(route, payment_hash, recipient_onion,
+                       keysend_preimage, payment_id, recv_value_msat, onion_session_privs, &self.node_signer,
+                       best_block_height, |args| self.send_payment_along_path(args))
        }
 
        #[cfg(test)]
@@ -3232,9 +3314,7 @@ where
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.send_spontaneous_payment_with_route(
                        route, payment_preimage, recipient_onion, payment_id, &self.entropy_source,
-                       &self.node_signer, best_block_height,
-                       |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       &self.node_signer, best_block_height, |args| self.send_payment_along_path(args))
        }
 
        /// Similar to [`ChannelManager::send_spontaneous_payment`], but will automatically find a route
@@ -3250,9 +3330,7 @@ where
                self.pending_outbound_payments.send_spontaneous_payment(payment_preimage, recipient_onion,
                        payment_id, retry_strategy, route_params, &self.router, self.list_usable_channels(),
                        || self.compute_inflight_htlcs(),  &self.entropy_source, &self.node_signer, best_block_height,
-                       &self.logger, &self.pending_events,
-                       |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       &self.logger, &self.pending_events, |args| self.send_payment_along_path(args))
        }
 
        /// Send a payment that is probing the given route for liquidity. We calculate the
@@ -3261,9 +3339,9 @@ where
        pub fn send_probe(&self, path: Path) -> Result<(PaymentHash, PaymentId), PaymentSendFailure> {
                let best_block_height = self.best_block.read().unwrap().height();
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               self.pending_outbound_payments.send_probe(path, self.probing_cookie_secret, &self.entropy_source, &self.node_signer, best_block_height,
-                       |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+               self.pending_outbound_payments.send_probe(path, self.probing_cookie_secret,
+                       &self.entropy_source, &self.node_signer, best_block_height,
+                       |args| self.send_payment_along_path(args))
        }
 
        /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
@@ -3288,7 +3366,7 @@ where
                        Some(chan) => {
                                let funding_txo = find_funding_output(&chan, &funding_transaction)?;
 
-                               let funding_res = chan.get_outbound_funding_created(funding_transaction, funding_txo, &self.logger)
+                               let funding_res = chan.get_funding_created(funding_transaction, funding_txo, &self.logger)
                                        .map_err(|(mut chan, e)| if let ChannelError::Close(msg) = e {
                                                let channel_id = chan.context.channel_id();
                                                let user_id = chan.context.get_user_id();
@@ -3461,27 +3539,48 @@ where
                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                let peer_state = &mut *peer_state_lock;
                for channel_id in channel_ids {
-                       if !peer_state.channel_by_id.contains_key(channel_id) {
+                       if !peer_state.has_channel(channel_id) {
                                return Err(APIError::ChannelUnavailable {
                                        err: format!("Channel with ID {} was not found for the passed counterparty_node_id {}", log_bytes!(*channel_id), counterparty_node_id),
                                });
-                       }
+                       };
                }
                for channel_id in channel_ids {
-                       let channel = peer_state.channel_by_id.get_mut(channel_id).unwrap();
-                       let mut config = channel.context.config();
-                       config.apply(config_update);
-                       if !channel.context.update_config(&config) {
+                       if let Some(channel) = peer_state.channel_by_id.get_mut(channel_id) {
+                               let mut config = channel.context.config();
+                               config.apply(config_update);
+                               if !channel.context.update_config(&config) {
+                                       continue;
+                               }
+                               if let Ok(msg) = self.get_channel_update_for_broadcast(channel) {
+                                       peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { msg });
+                               } else if let Ok(msg) = self.get_channel_update_for_unicast(channel) {
+                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
+                                               node_id: channel.context.get_counterparty_node_id(),
+                                               msg,
+                                       });
+                               }
                                continue;
                        }
-                       if let Ok(msg) = self.get_channel_update_for_broadcast(channel) {
-                               peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { msg });
-                       } else if let Ok(msg) = self.get_channel_update_for_unicast(channel) {
-                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
-                                       node_id: channel.context.get_counterparty_node_id(),
-                                       msg,
+
+                       let context = if let Some(channel) = peer_state.inbound_v1_channel_by_id.get_mut(channel_id) {
+                               &mut channel.context
+                       } else if let Some(channel) = peer_state.outbound_v1_channel_by_id.get_mut(channel_id) {
+                               &mut channel.context
+                       } else {
+                               // This should not be reachable as we've already checked for non-existence in the previous channel_id loop.
+                               debug_assert!(false);
+                               return Err(APIError::ChannelUnavailable {
+                                       err: format!(
+                                               "Channel with ID {} for passed counterparty_node_id {} disappeared after we confirmed its existence - this should not be reachable!",
+                                               log_bytes!(*channel_id), counterparty_node_id),
                                });
-                       }
+                       };
+                       let mut config = context.config();
+                       config.apply(config_update);
+                       // We update the config, but we MUST NOT broadcast a `channel_update` before `channel_ready`
+                       // which would be the case for pending inbound/outbound channels.
+                       context.update_config(&config);
                }
                Ok(())
        }
@@ -3778,7 +3877,8 @@ where
                                                                                });
                                                                                if let Err(e) = chan.get_mut().queue_add_htlc(outgoing_amt_msat,
                                                                                        payment_hash, outgoing_cltv_value, htlc_source.clone(),
-                                                                                       onion_packet, skimmed_fee_msat, &self.logger)
+                                                                                       onion_packet, skimmed_fee_msat, &self.fee_estimator,
+                                                                                       &self.logger)
                                                                                {
                                                                                        if let ChannelError::Ignore(msg) = e {
                                                                                                log_trace!(self.logger, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg);
@@ -4067,9 +4167,7 @@ where
                let best_block_height = self.best_block.read().unwrap().height();
                self.pending_outbound_payments.check_retry_payments(&self.router, || self.list_usable_channels(),
                        || self.compute_inflight_htlcs(), &self.entropy_source, &self.node_signer, best_block_height,
-                       &self.pending_events, &self.logger,
-                       |path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_hash, recipient_onion, total_value, cur_height, payment_id, keysend_preimage, session_priv));
+                       &self.pending_events, &self.logger, |args| self.send_payment_along_path(args));
 
                for (htlc_source, payment_hash, failure_reason, destination) in failed_forwards.drain(..) {
                        self.fail_htlc_backwards_internal(&htlc_source, &payment_hash, &failure_reason, destination);
@@ -4138,6 +4236,22 @@ where
                                        }
                                        let _ = handle_error!(self, res, counterparty_node_id);
                                },
+                               BackgroundEvent::MonitorUpdatesComplete { counterparty_node_id, channel_id } => {
+                                       let per_peer_state = self.per_peer_state.read().unwrap();
+                                       if let Some(peer_state_mutex) = per_peer_state.get(&counterparty_node_id) {
+                                               let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+                                               let peer_state = &mut *peer_state_lock;
+                                               if let Some(chan) = peer_state.channel_by_id.get_mut(&channel_id) {
+                                                       handle_monitor_update_completion!(self, peer_state_lock, peer_state, per_peer_state, chan);
+                                               } else {
+                                                       let update_actions = peer_state.monitor_update_blocked_actions
+                                                               .remove(&channel_id).unwrap_or(Vec::new());
+                                                       mem::drop(peer_state_lock);
+                                                       mem::drop(per_peer_state);
+                                                       self.handle_monitor_update_completion_actions(update_actions);
+                                               }
+                                       }
+                               },
                        }
                }
                NotifyOption::DoPersist
@@ -4166,7 +4280,7 @@ where
                log_trace!(self.logger, "Channel {} qualifies for a feerate change from {} to {}.",
                        log_bytes!(chan_id[..]), chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
 
-               chan.queue_update_fee(new_feerate, &self.logger);
+               chan.queue_update_fee(new_feerate, &self.fee_estimator, &self.logger);
                NotifyOption::DoPersist
        }
 
@@ -4179,13 +4293,19 @@ where
                PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
                        let mut should_persist = self.process_background_events();
 
-                       let new_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+                       let normal_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+                       let min_mempool_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::MempoolMinimum);
 
                        let per_peer_state = self.per_peer_state.read().unwrap();
                        for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
                                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                                let peer_state = &mut *peer_state_lock;
                                for (chan_id, chan) in peer_state.channel_by_id.iter_mut() {
+                                       let new_feerate = if chan.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                                               min_mempool_feerate
+                                       } else {
+                                               normal_feerate
+                                       };
                                        let chan_needs_persist = self.update_channel_fee(chan_id, chan, new_feerate);
                                        if chan_needs_persist == NotifyOption::DoPersist { should_persist = NotifyOption::DoPersist; }
                                }
@@ -4205,6 +4325,7 @@ where
        ///  * Expiring a channel's previous [`ChannelConfig`] if necessary to only allow forwarding HTLCs
        ///    with the current [`ChannelConfig`].
        ///  * Removing peers which have disconnected but and no longer have any channels.
+       ///  * Force-closing and removing channels which have not completed establishment in a timely manner.
        ///
        /// Note that this may cause reentrancy through [`chain::Watch::update_channel`] calls or feerate
        /// estimate fetches.
@@ -4215,7 +4336,8 @@ where
                PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
                        let mut should_persist = self.process_background_events();
 
-                       let new_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+                       let normal_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+                       let min_mempool_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::MempoolMinimum);
 
                        let mut handle_errors: Vec<(Result<(), _>, _)> = Vec::new();
                        let mut timed_out_mpp_htlcs = Vec::new();
@@ -4228,6 +4350,11 @@ where
                                        let pending_msg_events = &mut peer_state.pending_msg_events;
                                        let counterparty_node_id = *counterparty_node_id;
                                        peer_state.channel_by_id.retain(|chan_id, chan| {
+                                               let new_feerate = if chan.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                                                       min_mempool_feerate
+                                               } else {
+                                                       normal_feerate
+                                               };
                                                let chan_needs_persist = self.update_channel_fee(chan_id, chan, new_feerate);
                                                if chan_needs_persist == NotifyOption::DoPersist { should_persist = NotifyOption::DoPersist; }
 
@@ -4293,6 +4420,26 @@ where
 
                                                true
                                        });
+
+                                       let process_unfunded_channel_tick = |
+                                               chan_id: &[u8; 32],
+                                               chan_context: &mut ChannelContext<<SP::Target as SignerProvider>::Signer>,
+                                               unfunded_chan_context: &mut UnfundedChannelContext,
+                                       | {
+                                               chan_context.maybe_expire_prev_config();
+                                               if unfunded_chan_context.should_expire_unfunded_channel() {
+                                                       log_error!(self.logger, "Force-closing pending outbound channel {} for not establishing in a timely manner", log_bytes!(&chan_id[..]));
+                                                       update_maps_on_chan_removal!(self, &chan_context);
+                                                       self.issue_channel_close_events(&chan_context, ClosureReason::HolderForceClosed);
+                                                       self.finish_force_close_channel(chan_context.force_shutdown(false));
+                                                       false
+                                               } else {
+                                                       true
+                                               }
+                                       };
+                                       peer_state.outbound_v1_channel_by_id.retain(|chan_id, chan| process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context));
+                                       peer_state.inbound_v1_channel_by_id.retain(|chan_id, chan| process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context));
+
                                        if peer_state.ok_to_remove(true) {
                                                pending_peers_awaiting_removal.push(counterparty_node_id);
                                        }
@@ -4948,24 +5095,29 @@ where
                if peer_state_mutex_opt.is_none() { return }
                peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
                let peer_state = &mut *peer_state_lock;
-               let mut channel = {
-                       match peer_state.channel_by_id.entry(funding_txo.to_channel_id()){
-                               hash_map::Entry::Occupied(chan) => chan,
-                               hash_map::Entry::Vacant(_) => return,
-                       }
-               };
+               let channel =
+                       if let Some(chan) = peer_state.channel_by_id.get_mut(&funding_txo.to_channel_id()) {
+                               chan
+                       } else {
+                               let update_actions = peer_state.monitor_update_blocked_actions
+                                       .remove(&funding_txo.to_channel_id()).unwrap_or(Vec::new());
+                               mem::drop(peer_state_lock);
+                               mem::drop(per_peer_state);
+                               self.handle_monitor_update_completion_actions(update_actions);
+                               return;
+                       };
                let remaining_in_flight =
                        if let Some(pending) = peer_state.in_flight_monitor_updates.get_mut(funding_txo) {
                                pending.retain(|upd| upd.update_id > highest_applied_update_id);
                                pending.len()
                        } else { 0 };
                log_trace!(self.logger, "ChannelMonitor updated to {}. Current highest is {}. {} pending in-flight updates.",
-                       highest_applied_update_id, channel.get().context.get_latest_monitor_update_id(),
+                       highest_applied_update_id, channel.context.get_latest_monitor_update_id(),
                        remaining_in_flight);
-               if !channel.get().is_awaiting_monitor_update() || channel.get().context.get_latest_monitor_update_id() != highest_applied_update_id {
+               if !channel.is_awaiting_monitor_update() || channel.context.get_latest_monitor_update_id() != highest_applied_update_id {
                        return;
                }
-               handle_monitor_update_completion!(self, peer_state_lock, peer_state, per_peer_state, channel.get_mut());
+               handle_monitor_update_completion!(self, peer_state_lock, peer_state, per_peer_state, channel);
        }
 
        /// Accepts a request to open a channel after a [`Event::OpenChannelRequest`].
@@ -5398,38 +5550,50 @@ where
                                })?;
                        let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                        let peer_state = &mut *peer_state_lock;
-                       match peer_state.channel_by_id.entry(msg.channel_id.clone()) {
-                               hash_map::Entry::Occupied(mut chan_entry) => {
-
-                                       if !chan_entry.get().received_shutdown() {
-                                               log_info!(self.logger, "Received a shutdown message from our counterparty for channel {}{}.",
-                                                       log_bytes!(msg.channel_id),
-                                                       if chan_entry.get().sent_shutdown() { " after we initiated shutdown" } else { "" });
-                                       }
+                       // TODO(dunxen): Fix this duplication when we switch to a single map with enums as per
+                       // https://github.com/lightningdevkit/rust-lightning/issues/2422
+                       if let hash_map::Entry::Occupied(chan_entry) = peer_state.outbound_v1_channel_by_id.entry(msg.channel_id.clone()) {
+                               log_error!(self.logger, "Immediately closing unfunded channel {} as peer asked to cooperatively shut it down (which is unnecessary)", log_bytes!(&msg.channel_id[..]));
+                               self.issue_channel_close_events(&chan_entry.get().context, ClosureReason::CounterpartyCoopClosedUnfundedChannel);
+                               let mut chan = remove_channel!(self, chan_entry);
+                               self.finish_force_close_channel(chan.context.force_shutdown(false));
+                               return Ok(());
+                       } else if let hash_map::Entry::Occupied(chan_entry) = peer_state.inbound_v1_channel_by_id.entry(msg.channel_id.clone()) {
+                               log_error!(self.logger, "Immediately closing unfunded channel {} as peer asked to cooperatively shut it down (which is unnecessary)", log_bytes!(&msg.channel_id[..]));
+                               self.issue_channel_close_events(&chan_entry.get().context, ClosureReason::CounterpartyCoopClosedUnfundedChannel);
+                               let mut chan = remove_channel!(self, chan_entry);
+                               self.finish_force_close_channel(chan.context.force_shutdown(false));
+                               return Ok(());
+                       } else if let hash_map::Entry::Occupied(mut chan_entry) = peer_state.channel_by_id.entry(msg.channel_id.clone()) {
+                               if !chan_entry.get().received_shutdown() {
+                                       log_info!(self.logger, "Received a shutdown message from our counterparty for channel {}{}.",
+                                               log_bytes!(msg.channel_id),
+                                               if chan_entry.get().sent_shutdown() { " after we initiated shutdown" } else { "" });
+                               }
 
-                                       let funding_txo_opt = chan_entry.get().context.get_funding_txo();
-                                       let (shutdown, monitor_update_opt, htlcs) = try_chan_entry!(self,
-                                               chan_entry.get_mut().shutdown(&self.signer_provider, &peer_state.latest_features, &msg), chan_entry);
-                                       dropped_htlcs = htlcs;
+                               let funding_txo_opt = chan_entry.get().context.get_funding_txo();
+                               let (shutdown, monitor_update_opt, htlcs) = try_chan_entry!(self,
+                                       chan_entry.get_mut().shutdown(&self.signer_provider, &peer_state.latest_features, &msg), chan_entry);
+                               dropped_htlcs = htlcs;
 
-                                       if let Some(msg) = shutdown {
-                                               // We can send the `shutdown` message before updating the `ChannelMonitor`
-                                               // here as we don't need the monitor update to complete until we send a
-                                               // `shutdown_signed`, which we'll delay if we're pending a monitor update.
-                                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
-                                                       node_id: *counterparty_node_id,
-                                                       msg,
-                                               });
-                                       }
+                               if let Some(msg) = shutdown {
+                                       // We can send the `shutdown` message before updating the `ChannelMonitor`
+                                       // here as we don't need the monitor update to complete until we send a
+                                       // `shutdown_signed`, which we'll delay if we're pending a monitor update.
+                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
+                                               node_id: *counterparty_node_id,
+                                               msg,
+                                       });
+                               }
 
-                                       // Update the monitor with the shutdown script if necessary.
-                                       if let Some(monitor_update) = monitor_update_opt {
-                                               break handle_new_monitor_update!(self, funding_txo_opt.unwrap(), monitor_update,
-                                                       peer_state_lock, peer_state, per_peer_state, chan_entry).map(|_| ());
-                                       }
-                                       break Ok(());
-                               },
-                               hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
+                               // Update the monitor with the shutdown script if necessary.
+                               if let Some(monitor_update) = monitor_update_opt {
+                                       break handle_new_monitor_update!(self, funding_txo_opt.unwrap(), monitor_update,
+                                               peer_state_lock, peer_state, per_peer_state, chan_entry).map(|_| ());
+                               }
+                               break Ok(());
+                       } else {
+                               return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
                        }
                };
                for htlc_source in dropped_htlcs.drain(..) {
@@ -5539,7 +5703,7 @@ where
                                                _ => pending_forward_info
                                        }
                                };
-                               try_chan_entry!(self, chan.get_mut().update_add_htlc(&msg, pending_forward_info, create_pending_htlc_status, &self.logger), chan);
+                               try_chan_entry!(self, chan.get_mut().update_add_htlc(&msg, pending_forward_info, create_pending_htlc_status, &self.fee_estimator, &self.logger), chan);
                        },
                        hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
                }
@@ -5712,16 +5876,21 @@ where
                }
        }
 
-       // We only want to push a PendingHTLCsForwardable event if no others are queued.
        fn push_pending_forwards_ev(&self) {
                let mut pending_events = self.pending_events.lock().unwrap();
-               let forward_ev_exists = pending_events.iter()
-                       .find(|(ev, _)| if let events::Event::PendingHTLCsForwardable { .. } = ev { true } else { false })
-                       .is_some();
-               if !forward_ev_exists {
-                       pending_events.push_back((events::Event::PendingHTLCsForwardable {
-                               time_forwardable:
-                                       Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS),
+               let is_processing_events = self.pending_events_processor.load(Ordering::Acquire);
+               let num_forward_events = pending_events.iter().filter(|(ev, _)|
+                       if let events::Event::PendingHTLCsForwardable { .. } = ev { true } else { false }
+               ).count();
+               // We only want to push a PendingHTLCsForwardable event if no others are queued. Processing
+               // events is done in batches and they are not removed until we're done processing each
+               // batch. Since handling a `PendingHTLCsForwardable` event will call back into the
+               // `ChannelManager`, we'll still see the original forwarding event not removed. Phantom
+               // payments will need an additional forwarding event before being claimed to make them look
+               // real by taking more time.
+               if (is_processing_events && num_forward_events <= 1) || num_forward_events < 1 {
+                       pending_events.push_back((Event::PendingHTLCsForwardable {
+                               time_forwardable: Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS),
                        }, None));
                }
        }
@@ -5756,7 +5925,7 @@ where
                        match peer_state.channel_by_id.entry(msg.channel_id) {
                                hash_map::Entry::Occupied(mut chan) => {
                                        let funding_txo = chan.get().context.get_funding_txo();
-                                       let (htlcs_to_fail, monitor_update_opt) = try_chan_entry!(self, chan.get_mut().revoke_and_ack(&msg, &self.logger), chan);
+                                       let (htlcs_to_fail, monitor_update_opt) = try_chan_entry!(self, chan.get_mut().revoke_and_ack(&msg, &self.fee_estimator, &self.logger), chan);
                                        let res = if let Some(monitor_update) = monitor_update_opt {
                                                handle_new_monitor_update!(self, funding_txo.unwrap(), monitor_update,
                                                        peer_state_lock, peer_state, per_peer_state, chan).map(|_| ())
@@ -6027,7 +6196,7 @@ where
                                                let counterparty_node_id = chan.context.get_counterparty_node_id();
                                                let funding_txo = chan.context.get_funding_txo();
                                                let (monitor_opt, holding_cell_failed_htlcs) =
-                                                       chan.maybe_free_holding_cell_htlcs(&self.logger);
+                                                       chan.maybe_free_holding_cell_htlcs(&self.fee_estimator, &self.logger);
                                                if !holding_cell_failed_htlcs.is_empty() {
                                                        failed_htlcs.push((holding_cell_failed_htlcs, *channel_id, counterparty_node_id));
                                                }
@@ -6839,13 +7008,13 @@ where
                provided_node_features(&self.default_configuration)
        }
 
-       /// Fetches the set of [`InvoiceFeatures`] flags which are provided by or required by
+       /// Fetches the set of [`Bolt11InvoiceFeatures`] flags which are provided by or required by
        /// [`ChannelManager`].
        ///
        /// Note that the invoice feature flags can vary depending on if the invoice is a "phantom invoice"
        /// or not. Thus, this method is not public.
        #[cfg(any(feature = "_test_utils", test))]
-       pub fn invoice_features(&self) -> InvoiceFeatures {
+       pub fn invoice_features(&self) -> Bolt11InvoiceFeatures {
                provided_invoice_features(&self.default_configuration)
        }
 
@@ -7125,37 +7294,20 @@ where
                log_debug!(self.logger, "Generating channel_reestablish events for {}", log_pubkey!(counterparty_node_id));
 
                let per_peer_state = self.per_peer_state.read().unwrap();
-               for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
+               if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
                        let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                        let peer_state = &mut *peer_state_lock;
                        let pending_msg_events = &mut peer_state.pending_msg_events;
-                       peer_state.channel_by_id.retain(|_, chan| {
-                               let retain = if chan.context.get_counterparty_node_id() == *counterparty_node_id {
-                                       if !chan.context.have_received_message() {
-                                               // If we created this (outbound) channel while we were disconnected from the
-                                               // peer we probably failed to send the open_channel message, which is now
-                                               // lost. We can't have had anything pending related to this channel, so we just
-                                               // drop it.
-                                               false
-                                       } else {
-                                               pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
-                                                       node_id: chan.context.get_counterparty_node_id(),
-                                                       msg: chan.get_channel_reestablish(&self.logger),
-                                               });
-                                               true
-                                       }
-                               } else { true };
-                               if retain && chan.context.get_counterparty_node_id() != *counterparty_node_id {
-                                       if let Some(msg) = chan.get_signed_channel_announcement(&self.node_signer, self.genesis_hash.clone(), self.best_block.read().unwrap().height(), &self.default_configuration) {
-                                               if let Ok(update_msg) = self.get_channel_update_for_broadcast(chan) {
-                                                       pending_msg_events.push(events::MessageSendEvent::SendChannelAnnouncement {
-                                                               node_id: *counterparty_node_id,
-                                                               msg, update_msg,
-                                                       });
-                                               }
-                                       }
-                               }
-                               retain
+
+                       // Since unfunded channel maps are cleared upon disconnecting a peer, and they're not persisted
+                       // (so won't be recovered after a crash) we don't need to bother closing unfunded channels and
+                       // clearing their maps here. Instead we can just send queue channel_reestablish messages for
+                       // channels in the channel_by_id map.
+                       peer_state.channel_by_id.iter_mut().for_each(|(_, chan)| {
+                               pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
+                                       node_id: chan.context.get_counterparty_node_id(),
+                                       msg: chan.get_channel_reestablish(&self.logger),
+                               });
                        });
                }
                //TODO: Also re-broadcast announcement_signatures
@@ -7189,7 +7341,7 @@ where
                                let mut peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
                                let peer_state = &mut *peer_state_lock;
                                if let Some(chan) = peer_state.outbound_v1_channel_by_id.get_mut(&msg.channel_id) {
-                                       if let Ok(msg) = chan.maybe_handle_error_without_close(self.genesis_hash) {
+                                       if let Ok(msg) = chan.maybe_handle_error_without_close(self.genesis_hash, &self.fee_estimator) {
                                                peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
                                                        node_id: *counterparty_node_id,
                                                        msg,
@@ -7277,13 +7429,13 @@ pub(crate) fn provided_node_features(config: &UserConfig) -> NodeFeatures {
        provided_init_features(config).to_context()
 }
 
-/// Fetches the set of [`InvoiceFeatures`] flags which are provided by or required by
+/// Fetches the set of [`Bolt11InvoiceFeatures`] flags which are provided by or required by
 /// [`ChannelManager`].
 ///
 /// Note that the invoice feature flags can vary depending on if the invoice is a "phantom invoice"
 /// or not. Thus, this method is not public.
 #[cfg(any(feature = "_test_utils", test))]
-pub(crate) fn provided_invoice_features(config: &UserConfig) -> InvoiceFeatures {
+pub(crate) fn provided_invoice_features(config: &UserConfig) -> Bolt11InvoiceFeatures {
        provided_init_features(config).to_context()
 }
 
@@ -7375,6 +7527,7 @@ impl Writeable for ChannelDetails {
                        (35, self.inbound_htlc_maximum_msat, option),
                        (37, user_channel_id_high_opt, option),
                        (39, self.feerate_sat_per_1000_weight, option),
+                       (41, self.channel_shutdown_state, option),
                });
                Ok(())
        }
@@ -7412,6 +7565,7 @@ impl Readable for ChannelDetails {
                        (35, inbound_htlc_maximum_msat, option),
                        (37, user_channel_id_high_opt, option),
                        (39, feerate_sat_per_1000_weight, option),
+                       (41, channel_shutdown_state, option),
                });
 
                // `user_channel_id` used to be a single u64 value. In order to remain backwards compatible with
@@ -7447,12 +7601,13 @@ impl Readable for ChannelDetails {
                        inbound_htlc_minimum_msat,
                        inbound_htlc_maximum_msat,
                        feerate_sat_per_1000_weight,
+                       channel_shutdown_state,
                })
        }
 }
 
 impl_writeable_tlv_based!(PhantomRouteHints, {
-       (2, channels, vec_type),
+       (2, channels, required_vec),
        (4, phantom_scid, required),
        (6, real_node_pubkey, required),
 });
@@ -7644,7 +7799,7 @@ impl Readable for HTLCSource {
                        0 => {
                                let mut session_priv: crate::util::ser::RequiredWrapper<SecretKey> = crate::util::ser::RequiredWrapper(None);
                                let mut first_hop_htlc_msat: u64 = 0;
-                               let mut path_hops: Option<Vec<RouteHop>> = Some(Vec::new());
+                               let mut path_hops = Vec::new();
                                let mut payment_id = None;
                                let mut payment_params: Option<PaymentParameters> = None;
                                let mut blinded_tail: Option<BlindedTail> = None;
@@ -7652,7 +7807,7 @@ impl Readable for HTLCSource {
                                        (0, session_priv, required),
                                        (1, payment_id, option),
                                        (2, first_hop_htlc_msat, required),
-                                       (4, path_hops, vec_type),
+                                       (4, path_hops, required_vec),
                                        (5, payment_params, (option: ReadableArgs, 0)),
                                        (6, blinded_tail, option),
                                });
@@ -7661,7 +7816,7 @@ impl Readable for HTLCSource {
                                        // instead.
                                        payment_id = Some(PaymentId(*session_priv.0.unwrap().as_ref()));
                                }
-                               let path = Path { hops: path_hops.ok_or(DecodeError::InvalidValue)?, blinded_tail };
+                               let path = Path { hops: path_hops, blinded_tail };
                                if path.hops.len() == 0 {
                                        return Err(DecodeError::InvalidValue);
                                }
@@ -7696,7 +7851,7 @@ impl Writeable for HTLCSource {
                                        (1, payment_id_opt, option),
                                        (2, first_hop_htlc_msat, required),
                                        // 3 was previously used to write a PaymentSecret for the payment.
-                                       (4, path.hops, vec_type),
+                                       (4, path.hops, required_vec),
                                        (5, None::<PaymentParameters>, option), // payment_params in LDK versions prior to 0.0.115
                                        (6, path.blinded_tail, option),
                                 });
@@ -7946,7 +8101,7 @@ where
                        (6, monitor_update_blocked_actions_per_peer, option),
                        (7, self.fake_scid_rand_bytes, required),
                        (8, if events_not_backwards_compatible { Some(&*events) } else { None }, option),
-                       (9, htlc_purposes, vec_type),
+                       (9, htlc_purposes, required_vec),
                        (10, in_flight_monitor_updates, option),
                        (11, self.probing_cookie_secret, required),
                        (13, htlc_onion_fields, optional_vec),
@@ -7997,6 +8152,14 @@ impl Readable for VecDeque<(Event, Option<EventCompletionAction>)> {
        }
 }
 
+impl_writeable_tlv_based_enum!(ChannelShutdownState,
+       (0, NotShuttingDown) => {},
+       (2, ShutdownInitiated) => {},
+       (4, ResolvingHTLCs) => {},
+       (6, NegotiatingClosingFee) => {},
+       (8, ShutdownComplete) => {}, ;
+);
+
 /// Arguments for the creation of a ChannelManager that are not deserialized.
 ///
 /// At a high-level, the process for deserializing a ChannelManager and resuming normal operation
@@ -8385,7 +8548,7 @@ where
                        (6, monitor_update_blocked_actions_per_peer, option),
                        (7, fake_scid_rand_bytes, option),
                        (8, events_override, option),
-                       (9, claimable_htlc_purposes, vec_type),
+                       (9, claimable_htlc_purposes, optional_vec),
                        (10, in_flight_monitor_updates, option),
                        (11, probing_cookie_secret, option),
                        (13, claimable_htlc_onion_fields, optional_vec),
@@ -8449,6 +8612,16 @@ where
                                                        update: update.clone(),
                                                });
                                }
+                               if $chan_in_flight_upds.is_empty() {
+                                       // We had some updates to apply, but it turns out they had completed before we
+                                       // were serialized, we just weren't notified of that. Thus, we may have to run
+                                       // the completion actions for any monitor updates, but otherwise are done.
+                                       pending_background_events.push(
+                                               BackgroundEvent::MonitorUpdatesComplete {
+                                                       counterparty_node_id: $counterparty_node_id,
+                                                       channel_id: $funding_txo.to_channel_id(),
+                                               });
+                               }
                                if $peer_state.in_flight_monitor_updates.insert($funding_txo, $chan_in_flight_upds).is_some() {
                                        log_error!(args.logger, "Duplicate in-flight monitor update set for the same channel!");
                                        return Err(DecodeError::InvalidValue);
@@ -8841,6 +9014,12 @@ where
                                                                blocked_peer_state.lock().unwrap().actions_blocking_raa_monitor_updates
                                                                        .entry(blocked_channel_outpoint.to_channel_id())
                                                                        .or_insert_with(Vec::new).push(blocking_action.clone());
+                                                       } else {
+                                                               // If the channel we were blocking has closed, we don't need to
+                                                               // worry about it - the blocked monitor update should never have
+                                                               // been released from the `Channel` object so it can't have
+                                                               // completed, and if the channel closed there's no reason to bother
+                                                               // anymore.
                                                        }
                                                }
                                        }
@@ -10058,6 +10237,25 @@ mod tests {
                        MessageSendEvent::BroadcastChannelUpdate { .. } => {},
                        _ => panic!("expected BroadcastChannelUpdate event"),
                }
+
+               // If we provide a channel_id not associated with the peer, we should get an error and no updates
+               // should be applied to ensure update atomicity as specified in the API docs.
+               let bad_channel_id = [10; 32];
+               let current_fee = nodes[0].node.list_channels()[0].config.unwrap().forwarding_fee_proportional_millionths;
+               let new_fee = current_fee + 100;
+               assert!(
+                       matches!(
+                               nodes[0].node.update_partial_channel_config(&channel.counterparty.node_id, &[channel.channel_id, bad_channel_id], &ChannelConfigUpdate {
+                                       forwarding_fee_proportional_millionths: Some(new_fee),
+                                       ..Default::default()
+                               }),
+                               Err(APIError::ChannelUnavailable { err: _ }),
+                       )
+               );
+               // Check that the fee hasn't changed for the channel that exists.
+               assert_eq!(nodes[0].node.list_channels()[0].config.unwrap().forwarding_fee_proportional_millionths, current_fee);
+               let events = nodes[0].node.get_and_clear_pending_msg_events();
+               assert_eq!(events.len(), 0);
        }
 }
 
@@ -10073,7 +10271,7 @@ pub mod bench {
        use crate::routing::gossip::NetworkGraph;
        use crate::routing::router::{PaymentParameters, RouteParameters};
        use crate::util::test_utils;
-       use crate::util::config::UserConfig;
+       use crate::util::config::{UserConfig, MaxDustHTLCExposure};
 
        use bitcoin::hashes::Hash;
        use bitcoin::hashes::sha256::Hash as Sha256;
@@ -10111,6 +10309,7 @@ pub mod bench {
                // Note that this is unrealistic as each payment send will require at least two fsync
                // calls per node.
                let network = bitcoin::Network::Testnet;
+               let genesis_block = bitcoin::blockdata::constants::genesis_block(network);
 
                let tx_broadcaster = test_utils::TestBroadcaster::new(network);
                let fee_estimator = test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) };
@@ -10119,6 +10318,7 @@ pub mod bench {
                let router = test_utils::TestRouter::new(Arc::new(NetworkGraph::new(network, &logger_a)), &scorer);
 
                let mut config: UserConfig = Default::default();
+               config.channel_config.max_dust_htlc_exposure = MaxDustHTLCExposure::FeeRateMultiplier(5_000_000 / 253);
                config.channel_handshake_config.minimum_depth = 1;
 
                let chain_monitor_a = ChainMonitor::new(None, &tx_broadcaster, &logger_a, &fee_estimator, &persister_a);
@@ -10127,7 +10327,7 @@ pub mod bench {
                let node_a = ChannelManager::new(&fee_estimator, &chain_monitor_a, &tx_broadcaster, &router, &logger_a, &keys_manager_a, &keys_manager_a, &keys_manager_a, config.clone(), ChainParameters {
                        network,
                        best_block: BestBlock::from_network(network),
-               });
+               }, genesis_block.header.time);
                let node_a_holder = ANodeHolder { node: &node_a };
 
                let logger_b = test_utils::TestLogger::with_id("node a".to_owned());
@@ -10137,7 +10337,7 @@ pub mod bench {
                let node_b = ChannelManager::new(&fee_estimator, &chain_monitor_b, &tx_broadcaster, &router, &logger_b, &keys_manager_b, &keys_manager_b, &keys_manager_b, config.clone(), ChainParameters {
                        network,
                        best_block: BestBlock::from_network(network),
-               });
+               }, genesis_block.header.time);
                let node_b_holder = ANodeHolder { node: &node_b };
 
                node_a.peer_connected(&node_b.get_our_node_id(), &Init {