Add a payments section to ChannelManager docs
[rust-lightning] / lightning / src / ln / channelmanager.rs
index ec3e8ef604b2ff077aa4cb53f143f8d915f3bac8..dc170b652b55bc953ee121d3109e5d2ecb77e8df 100644 (file)
@@ -44,6 +44,7 @@ use crate::events::{Event, EventHandler, EventsProvider, MessageSendEvent, Messa
 // construct one themselves.
 use crate::ln::{inbound_payment, ChannelId, PaymentHash, PaymentPreimage, PaymentSecret};
 use crate::ln::channel::{self, Channel, ChannelPhase, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UnfundedChannelContext, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel, WithChannelContext};
+pub use crate::ln::channel::{InboundHTLCDetails, InboundHTLCStateDetails, OutboundHTLCDetails, OutboundHTLCStateDetails};
 use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
 #[cfg(any(feature = "_test_utils", test))]
 use crate::ln::features::Bolt11InvoiceFeatures;
@@ -57,10 +58,11 @@ use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
 use crate::ln::outbound_payment;
 use crate::ln::outbound_payment::{Bolt12PaymentError, OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration};
 use crate::ln::wire::Encode;
-use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, InvoiceBuilder};
+use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder, UnsignedBolt12Invoice};
 use crate::offers::invoice_error::InvoiceError;
+use crate::offers::invoice_request::{DerivedPayerId, InvoiceRequestBuilder};
 use crate::offers::merkle::SignError;
-use crate::offers::offer::{DerivedMetadata, Offer, OfferBuilder};
+use crate::offers::offer::{Offer, OfferBuilder};
 use crate::offers::parse::Bolt12SemanticError;
 use crate::offers::refund::{Refund, RefundBuilder};
 use crate::onion_message::messenger::{Destination, MessageRouter, PendingOnionMessage, new_pending_onion_message};
@@ -76,11 +78,17 @@ use crate::util::logger::{Level, Logger, WithContext};
 use crate::util::errors::APIError;
 #[cfg(not(c_bindings))]
 use {
+       crate::offers::offer::DerivedMetadata,
        crate::routing::router::DefaultRouter,
        crate::routing::gossip::NetworkGraph,
        crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters},
        crate::sign::KeysManager,
 };
+#[cfg(c_bindings)]
+use {
+       crate::offers::offer::OfferWithDerivedMetadataBuilder,
+       crate::offers::refund::RefundMaybeWithDerivedMetadataBuilder,
+};
 
 use alloc::collections::{btree_map, BTreeMap};
 
@@ -192,6 +200,8 @@ pub enum PendingHTLCRouting {
                /// For HTLCs received by LDK, these will ultimately bubble back up as
                /// [`RecipientOnionFields::custom_tlvs`].
                custom_tlvs: Vec<(u64, Vec<u8>)>,
+               /// Set if this HTLC is the final hop in a multi-hop blinded path.
+               requires_blinded_error: bool,
        },
 }
 
@@ -213,6 +223,7 @@ impl PendingHTLCRouting {
                match self {
                        Self::Forward { blinded: Some(BlindedForward { failure, .. }), .. } => Some(*failure),
                        Self::Receive { requires_blinded_error: true, .. } => Some(BlindedFailure::FromBlindedNode),
+                       Self::ReceiveKeysend { requires_blinded_error: true, .. } => Some(BlindedFailure::FromBlindedNode),
                        _ => None,
                }
        }
@@ -288,6 +299,7 @@ pub(super) struct PendingAddHTLCInfo {
        // Note that this may be an outbound SCID alias for the associated channel.
        prev_short_channel_id: u64,
        prev_htlc_id: u64,
+       prev_channel_id: ChannelId,
        prev_funding_outpoint: OutPoint,
        prev_user_channel_id: u128,
 }
@@ -328,6 +340,7 @@ pub(crate) struct HTLCPreviousHopData {
        incoming_packet_shared_secret: [u8; 32],
        phantom_shared_secret: Option<[u8; 32]>,
        blinded_failure: Option<BlindedFailure>,
+       channel_id: ChannelId,
 
        // This field is consumed by `claim_funds_from_hop()` when updating a force-closed backwards
        // channel with a preimage provided by the forward channel.
@@ -368,7 +381,7 @@ struct ClaimableHTLC {
 impl From<&ClaimableHTLC> for events::ClaimedHTLC {
        fn from(val: &ClaimableHTLC) -> Self {
                events::ClaimedHTLC {
-                       channel_id: val.prev_hop.outpoint.to_channel_id(),
+                       channel_id: val.prev_hop.channel_id,
                        user_channel_id: val.prev_hop.user_channel_id.unwrap_or(0),
                        cltv_expiry: val.cltv_expiry,
                        value_msat: val.value,
@@ -707,7 +720,7 @@ enum BackgroundEvent {
        ///
        /// Note that any such events are lost on shutdown, so in general they must be updates which
        /// are regenerated on startup.
-       ClosedMonitorUpdateRegeneratedOnStartup((OutPoint, ChannelMonitorUpdate)),
+       ClosedMonitorUpdateRegeneratedOnStartup((OutPoint, ChannelId, ChannelMonitorUpdate)),
        /// Handle a ChannelMonitorUpdate which may or may not close the channel and may unblock the
        /// channel to continue normal operation.
        ///
@@ -721,6 +734,7 @@ enum BackgroundEvent {
        MonitorUpdateRegeneratedOnStartup {
                counterparty_node_id: PublicKey,
                funding_txo: OutPoint,
+               channel_id: ChannelId,
                update: ChannelMonitorUpdate
        },
        /// Some [`ChannelMonitorUpdate`] (s) completed before we were serialized but we still have
@@ -749,7 +763,7 @@ pub(crate) enum MonitorUpdateCompletionAction {
        /// outbound edge.
        EmitEventAndFreeOtherChannel {
                event: events::Event,
-               downstream_counterparty_and_funding_outpoint: Option<(PublicKey, OutPoint, RAAMonitorUpdateBlockingAction)>,
+               downstream_counterparty_and_funding_outpoint: Option<(PublicKey, OutPoint, ChannelId, RAAMonitorUpdateBlockingAction)>,
        },
        /// Indicates we should immediately resume the operation of another channel, unless there is
        /// some other reason why the channel is blocked. In practice this simply means immediately
@@ -767,6 +781,7 @@ pub(crate) enum MonitorUpdateCompletionAction {
                downstream_counterparty_node_id: PublicKey,
                downstream_funding_outpoint: OutPoint,
                blocking_action: RAAMonitorUpdateBlockingAction,
+               downstream_channel_id: ChannelId,
        },
 }
 
@@ -778,6 +793,9 @@ impl_writeable_tlv_based_enum_upgradable!(MonitorUpdateCompletionAction,
                (0, downstream_counterparty_node_id, required),
                (2, downstream_funding_outpoint, required),
                (4, blocking_action, required),
+               // Note that by the time we get past the required read above, downstream_funding_outpoint will be
+               // filled in, so we can safely unwrap it here.
+               (5, downstream_channel_id, (default_value, ChannelId::v1_from_funding_outpoint(downstream_funding_outpoint.0.unwrap()))),
        },
        (2, EmitEventAndFreeOtherChannel) => {
                (0, event, upgradable_required),
@@ -795,12 +813,16 @@ pub(crate) enum EventCompletionAction {
        ReleaseRAAChannelMonitorUpdate {
                counterparty_node_id: PublicKey,
                channel_funding_outpoint: OutPoint,
+               channel_id: ChannelId,
        },
 }
 impl_writeable_tlv_based_enum!(EventCompletionAction,
        (0, ReleaseRAAChannelMonitorUpdate) => {
                (0, channel_funding_outpoint, required),
                (2, counterparty_node_id, required),
+               // Note that by the time we get past the required read above, channel_funding_outpoint will be
+               // filled in, so we can safely unwrap it here.
+               (3, channel_id, (default_value, ChannelId::v1_from_funding_outpoint(channel_funding_outpoint.0.unwrap()))),
        };
 );
 
@@ -822,7 +844,7 @@ pub(crate) enum RAAMonitorUpdateBlockingAction {
 impl RAAMonitorUpdateBlockingAction {
        fn from_prev_hop_data(prev_hop: &HTLCPreviousHopData) -> Self {
                Self::ForwardedPaymentInboundClaim {
-                       channel_id: prev_hop.outpoint.to_channel_id(),
+                       channel_id: prev_hop.channel_id,
                        htlc_id: prev_hop.htlc_id,
                }
        }
@@ -892,7 +914,16 @@ impl <SP: Deref> PeerState<SP> where SP::Target: SignerProvider {
                if require_disconnected && self.is_connected {
                        return false
                }
-               self.channel_by_id.iter().filter(|(_, phase)| matches!(phase, ChannelPhase::Funded(_))).count() == 0
+               !self.channel_by_id.iter().any(|(_, phase)|
+                       match phase {
+                               ChannelPhase::Funded(_) | ChannelPhase::UnfundedOutboundV1(_) => true,
+                               ChannelPhase::UnfundedInboundV1(_) => false,
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedOutboundV2(_) => true,
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedInboundV2(_) => false,
+                       }
+               )
                        && self.monitor_update_blocked_actions.is_empty()
                        && self.in_flight_monitor_updates.is_empty()
        }
@@ -964,6 +995,7 @@ pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<
        Arc<DefaultRouter<
                Arc<NetworkGraph<Arc<L>>>,
                Arc<L>,
+               Arc<KeysManager>,
                Arc<RwLock<ProbabilisticScorer<Arc<NetworkGraph<Arc<L>>>, Arc<L>>>>,
                ProbabilisticScoringFeeParameters,
                ProbabilisticScorer<Arc<NetworkGraph<Arc<L>>>, Arc<L>>,
@@ -994,6 +1026,7 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> =
                &'e DefaultRouter<
                        &'f NetworkGraph<&'g L>,
                        &'g L,
+                       &'c KeysManager,
                        &'h RwLock<ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>>,
                        ProbabilisticScoringFeeParameters,
                        ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>
@@ -1076,11 +1109,424 @@ where
        fn get_cm(&self) -> &ChannelManager<M, T, ES, NS, SP, F, R, L> { self }
 }
 
-/// Manager which keeps track of a number of channels and sends messages to the appropriate
-/// channel, also tracking HTLC preimages and forwarding onion packets appropriately.
+/// A lightning node's channel state machine and payment management logic, which facilitates
+/// sending, forwarding, and receiving payments through lightning channels.
+///
+/// [`ChannelManager`] is parameterized by a number of components to achieve this.
+/// - [`chain::Watch`] (typically [`ChainMonitor`]) for on-chain monitoring and enforcement of each
+///   channel
+/// - [`BroadcasterInterface`] for broadcasting transactions related to opening, funding, and
+///   closing channels
+/// - [`EntropySource`] for providing random data needed for cryptographic operations
+/// - [`NodeSigner`] for cryptographic operations scoped to the node
+/// - [`SignerProvider`] for providing signers whose operations are scoped to individual channels
+/// - [`FeeEstimator`] to determine transaction fee rates needed to have a transaction mined in a
+///   timely manner
+/// - [`Router`] for finding payment paths when initiating and retrying payments
+/// - [`Logger`] for logging operational information of varying degrees
+///
+/// Additionally, it implements the following traits:
+/// - [`ChannelMessageHandler`] to handle off-chain channel activity from peers
+/// - [`MessageSendEventsProvider`] to similarly send such messages to peers
+/// - [`OffersMessageHandler`] for BOLT 12 message handling and sending
+/// - [`EventsProvider`] to generate user-actionable [`Event`]s
+/// - [`chain::Listen`] and [`chain::Confirm`] for notification of on-chain activity
+///
+/// Thus, [`ChannelManager`] is typically used to parameterize a [`MessageHandler`] and an
+/// [`OnionMessenger`]. The latter is required to support BOLT 12 functionality.
+///
+/// # `ChannelManager` vs `ChannelMonitor`
+///
+/// It's important to distinguish between the *off-chain* management and *on-chain* enforcement of
+/// lightning channels. [`ChannelManager`] exchanges messages with peers to manage the off-chain
+/// state of each channel. During this process, it generates a [`ChannelMonitor`] for each channel
+/// and a [`ChannelMonitorUpdate`] for each relevant change, notifying its parameterized
+/// [`chain::Watch`] of them.
+///
+/// An implementation of [`chain::Watch`], such as [`ChainMonitor`], is responsible for aggregating
+/// these [`ChannelMonitor`]s and applying any [`ChannelMonitorUpdate`]s to them. It then monitors
+/// for any pertinent on-chain activity, enforcing claims as needed.
+///
+/// This division of off-chain management and on-chain enforcement allows for interesting node
+/// setups. For instance, on-chain enforcement could be moved to a separate host or have added
+/// redundancy, possibly as a watchtower. See [`chain::Watch`] for the relevant interface.
+///
+/// # Initialization
+///
+/// Use [`ChannelManager::new`] with the most recent [`BlockHash`] when creating a fresh instance.
+/// Otherwise, if restarting, construct [`ChannelManagerReadArgs`] with the necessary parameters and
+/// references to any deserialized [`ChannelMonitor`]s that were previously persisted. Use this to
+/// deserialize the [`ChannelManager`] and feed it any new chain data since it was last online, as
+/// detailed in the [`ChannelManagerReadArgs`] documentation.
+///
+/// ```
+/// use bitcoin::BlockHash;
+/// use bitcoin::network::constants::Network;
+/// use lightning::chain::BestBlock;
+/// # use lightning::chain::channelmonitor::ChannelMonitor;
+/// use lightning::ln::channelmanager::{ChainParameters, ChannelManager, ChannelManagerReadArgs};
+/// # use lightning::routing::gossip::NetworkGraph;
+/// use lightning::util::config::UserConfig;
+/// use lightning::util::ser::ReadableArgs;
+///
+/// # fn read_channel_monitors() -> Vec<ChannelMonitor<lightning::sign::InMemorySigner>> { vec![] }
+/// # fn example<
+/// #     'a,
+/// #     L: lightning::util::logger::Logger,
+/// #     ES: lightning::sign::EntropySource,
+/// #     S: for <'b> lightning::routing::scoring::LockableScore<'b, ScoreLookUp = SL>,
+/// #     SL: lightning::routing::scoring::ScoreLookUp<ScoreParams = SP>,
+/// #     SP: Sized,
+/// #     R: lightning::io::Read,
+/// # >(
+/// #     fee_estimator: &dyn lightning::chain::chaininterface::FeeEstimator,
+/// #     chain_monitor: &dyn lightning::chain::Watch<lightning::sign::InMemorySigner>,
+/// #     tx_broadcaster: &dyn lightning::chain::chaininterface::BroadcasterInterface,
+/// #     router: &lightning::routing::router::DefaultRouter<&NetworkGraph<&'a L>, &'a L, &ES, &S, SP, SL>,
+/// #     logger: &L,
+/// #     entropy_source: &ES,
+/// #     node_signer: &dyn lightning::sign::NodeSigner,
+/// #     signer_provider: &lightning::sign::DynSignerProvider,
+/// #     best_block: lightning::chain::BestBlock,
+/// #     current_timestamp: u32,
+/// #     mut reader: R,
+/// # ) -> Result<(), lightning::ln::msgs::DecodeError> {
+/// // Fresh start with no channels
+/// let params = ChainParameters {
+///     network: Network::Bitcoin,
+///     best_block,
+/// };
+/// let default_config = UserConfig::default();
+/// let channel_manager = ChannelManager::new(
+///     fee_estimator, chain_monitor, tx_broadcaster, router, logger, entropy_source, node_signer,
+///     signer_provider, default_config, params, current_timestamp
+/// );
+///
+/// // Restart from deserialized data
+/// let mut channel_monitors = read_channel_monitors();
+/// let args = ChannelManagerReadArgs::new(
+///     entropy_source, node_signer, signer_provider, fee_estimator, chain_monitor, tx_broadcaster,
+///     router, logger, default_config, channel_monitors.iter_mut().collect()
+/// );
+/// let (block_hash, channel_manager) =
+///     <(BlockHash, ChannelManager<_, _, _, _, _, _, _, _>)>::read(&mut reader, args)?;
+///
+/// // Update the ChannelManager and ChannelMonitors with the latest chain data
+/// // ...
+///
+/// // Move the monitors to the ChannelManager's chain::Watch parameter
+/// for monitor in channel_monitors {
+///     chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor);
+/// }
+/// # Ok(())
+/// # }
+/// ```
+///
+/// # Operation
+///
+/// The following is required for [`ChannelManager`] to function properly:
+/// - Handle messages from peers using its [`ChannelMessageHandler`] implementation (typically
+///   called by [`PeerManager::read_event`] when processing network I/O)
+/// - Send messages to peers obtained via its [`MessageSendEventsProvider`] implementation
+///   (typically initiated when [`PeerManager::process_events`] is called)
+/// - Feed on-chain activity using either its [`chain::Listen`] or [`chain::Confirm`] implementation
+///   as documented by those traits
+/// - Perform any periodic channel and payment checks by calling [`timer_tick_occurred`] roughly
+///   every minute
+/// - Persist to disk whenever [`get_and_clear_needs_persistence`] returns `true` using a
+///   [`Persister`] such as a [`KVStore`] implementation
+/// - Handle [`Event`]s obtained via its [`EventsProvider`] implementation
+///
+/// The [`Future`] returned by [`get_event_or_persistence_needed_future`] is useful in determining
+/// when the last two requirements need to be checked.
+///
+/// The [`lightning-block-sync`] and [`lightning-transaction-sync`] crates provide utilities that
+/// simplify feeding in on-chain activity using the [`chain::Listen`] and [`chain::Confirm`] traits,
+/// respectively. The remaining requirements can be met using the [`lightning-background-processor`]
+/// crate. For languages other than Rust, the availability of similar utilities may vary.
+///
+/// # Channels
+///
+/// [`ChannelManager`]'s primary function involves managing a channel state. Without channels,
+/// payments can't be sent. Use [`list_channels`] or [`list_usable_channels`] for a snapshot of the
+/// currently open channels.
+///
+/// ```
+/// # use lightning::ln::channelmanager::AChannelManager;
+/// #
+/// # fn example<T: AChannelManager>(channel_manager: T) {
+/// # let channel_manager = channel_manager.get_cm();
+/// let channels = channel_manager.list_usable_channels();
+/// for details in channels {
+///     println!("{:?}", details);
+/// }
+/// # }
+/// ```
+///
+/// Each channel is identified using a [`ChannelId`], which will change throughout the channel's
+/// life cycle. Additionally, channels are assigned a `user_channel_id`, which is given in
+/// [`Event`]s associated with the channel and serves as a fixed identifier but is otherwise unused
+/// by [`ChannelManager`].
 ///
-/// Implements [`ChannelMessageHandler`], handling the multi-channel parts and passing things through
-/// to individual Channels.
+/// ## Opening Channels
+///
+/// To an open a channel with a peer, call [`create_channel`]. This will initiate the process of
+/// opening an outbound channel, which requires self-funding when handling
+/// [`Event::FundingGenerationReady`].
+///
+/// ```
+/// # use bitcoin::{ScriptBuf, Transaction};
+/// # use bitcoin::secp256k1::PublicKey;
+/// # use lightning::ln::channelmanager::AChannelManager;
+/// # use lightning::events::{Event, EventsProvider};
+/// #
+/// # trait Wallet {
+/// #     fn create_funding_transaction(
+/// #         &self, _amount_sats: u64, _output_script: ScriptBuf
+/// #     ) -> Transaction;
+/// # }
+/// #
+/// # fn example<T: AChannelManager, W: Wallet>(channel_manager: T, wallet: W, peer_id: PublicKey) {
+/// # let channel_manager = channel_manager.get_cm();
+/// let value_sats = 1_000_000;
+/// let push_msats = 10_000_000;
+/// match channel_manager.create_channel(peer_id, value_sats, push_msats, 42, None, None) {
+///     Ok(channel_id) => println!("Opening channel {}", channel_id),
+///     Err(e) => println!("Error opening channel: {:?}", e),
+/// }
+///
+/// // On the event processing thread once the peer has responded
+/// channel_manager.process_pending_events(&|event| match event {
+///     Event::FundingGenerationReady {
+///         temporary_channel_id, counterparty_node_id, channel_value_satoshis, output_script,
+///         user_channel_id, ..
+///     } => {
+///         assert_eq!(user_channel_id, 42);
+///         let funding_transaction = wallet.create_funding_transaction(
+///             channel_value_satoshis, output_script
+///         );
+///         match channel_manager.funding_transaction_generated(
+///             &temporary_channel_id, &counterparty_node_id, funding_transaction
+///         ) {
+///             Ok(()) => println!("Funding channel {}", temporary_channel_id),
+///             Err(e) => println!("Error funding channel {}: {:?}", temporary_channel_id, e),
+///         }
+///     },
+///     Event::ChannelPending { channel_id, user_channel_id, former_temporary_channel_id, .. } => {
+///         assert_eq!(user_channel_id, 42);
+///         println!(
+///             "Channel {} now {} pending (funding transaction has been broadcasted)", channel_id,
+///             former_temporary_channel_id.unwrap()
+///         );
+///     },
+///     Event::ChannelReady { channel_id, user_channel_id, .. } => {
+///         assert_eq!(user_channel_id, 42);
+///         println!("Channel {} ready", channel_id);
+///     },
+///     // ...
+/// #     _ => {},
+/// });
+/// # }
+/// ```
+///
+/// ## Accepting Channels
+///
+/// Inbound channels are initiated by peers and are automatically accepted unless [`ChannelManager`]
+/// has [`UserConfig::manually_accept_inbound_channels`] set. In that case, the channel may be
+/// either accepted or rejected when handling [`Event::OpenChannelRequest`].
+///
+/// ```
+/// # use bitcoin::secp256k1::PublicKey;
+/// # use lightning::ln::channelmanager::AChannelManager;
+/// # use lightning::events::{Event, EventsProvider};
+/// #
+/// # fn is_trusted(counterparty_node_id: PublicKey) -> bool {
+/// #     // ...
+/// #     unimplemented!()
+/// # }
+/// #
+/// # fn example<T: AChannelManager>(channel_manager: T) {
+/// # let channel_manager = channel_manager.get_cm();
+/// channel_manager.process_pending_events(&|event| match event {
+///     Event::OpenChannelRequest { temporary_channel_id, counterparty_node_id, ..  } => {
+///         if !is_trusted(counterparty_node_id) {
+///             match channel_manager.force_close_without_broadcasting_txn(
+///                 &temporary_channel_id, &counterparty_node_id
+///             ) {
+///                 Ok(()) => println!("Rejecting channel {}", temporary_channel_id),
+///                 Err(e) => println!("Error rejecting channel {}: {:?}", temporary_channel_id, e),
+///             }
+///             return;
+///         }
+///
+///         let user_channel_id = 43;
+///         match channel_manager.accept_inbound_channel(
+///             &temporary_channel_id, &counterparty_node_id, user_channel_id
+///         ) {
+///             Ok(()) => println!("Accepting channel {}", temporary_channel_id),
+///             Err(e) => println!("Error accepting channel {}: {:?}", temporary_channel_id, e),
+///         }
+///     },
+///     // ...
+/// #     _ => {},
+/// });
+/// # }
+/// ```
+///
+/// ## Closing Channels
+///
+/// There are two ways to close a channel: either cooperatively using [`close_channel`] or
+/// unilaterally using [`force_close_broadcasting_latest_txn`]. The former is ideal as it makes for
+/// lower fees and immediate access to funds. However, the latter may be necessary if the
+/// counterparty isn't behaving properly or has gone offline. [`Event::ChannelClosed`] is generated
+/// once the channel has been closed successfully.
+///
+/// ```
+/// # use bitcoin::secp256k1::PublicKey;
+/// # use lightning::ln::ChannelId;
+/// # use lightning::ln::channelmanager::AChannelManager;
+/// # use lightning::events::{Event, EventsProvider};
+/// #
+/// # fn example<T: AChannelManager>(
+/// #     channel_manager: T, channel_id: ChannelId, counterparty_node_id: PublicKey
+/// # ) {
+/// # let channel_manager = channel_manager.get_cm();
+/// match channel_manager.close_channel(&channel_id, &counterparty_node_id) {
+///     Ok(()) => println!("Closing channel {}", channel_id),
+///     Err(e) => println!("Error closing channel {}: {:?}", channel_id, e),
+/// }
+///
+/// // On the event processing thread
+/// channel_manager.process_pending_events(&|event| match event {
+///     Event::ChannelClosed { channel_id, user_channel_id, ..  } => {
+///         assert_eq!(user_channel_id, 42);
+///         println!("Channel {} closed", channel_id);
+///     },
+///     // ...
+/// #     _ => {},
+/// });
+/// # }
+/// ```
+///
+/// # Payments
+///
+/// [`ChannelManager`] is responsible for sending, forwarding, and receiving payments through its
+/// channels. A payment is typically initiated from a [BOLT 11] invoice or a [BOLT 12] offer, though
+/// spontaneous (i.e., keysend) payments are also possible. Incoming payments don't require
+/// maintaining any additional state as [`ChannelManager`] can reconstruct the [`PaymentPreimage`]
+/// from the [`PaymentSecret`]. Sending payments, however, require tracking in order to retry failed
+/// HTLCs.
+///
+/// After a payment is initiated, it will appear in [`list_recent_payments`] until a short time
+/// after either an [`Event::PaymentSent`] or [`Event::PaymentFailed`] is handled. Failed HTLCs
+/// for a payment will be retried according to the payment's [`Retry`] strategy or until
+/// [`abandon_payment`] is called.
+///
+/// ## BOLT 11 Invoices
+///
+/// The [`lightning-invoice`] crate is useful for creating BOLT 11 invoices. Specifically, use the
+/// functions in its `utils` module for constructing invoices that are compatible with
+/// [`ChannelManager`]. These functions serve as a convenience for building invoices with the
+/// [`PaymentHash`] and [`PaymentSecret`] returned from [`create_inbound_payment`]. To provide your
+/// own [`PaymentHash`], use [`create_inbound_payment_for_hash`] or the corresponding functions in
+/// the [`lightning-invoice`] `utils` module.
+///
+/// [`ChannelManager`] generates an [`Event::PaymentClaimable`] once the full payment has been
+/// received. Call [`claim_funds`] to release the [`PaymentPreimage`], which in turn will result in
+/// an [`Event::PaymentClaimed`].
+///
+/// ```
+/// # use lightning::events::{Event, EventsProvider, PaymentPurpose};
+/// # use lightning::ln::channelmanager::AChannelManager;
+/// #
+/// # fn example<T: AChannelManager>(channel_manager: T) {
+/// # let channel_manager = channel_manager.get_cm();
+/// // Or use utils::create_invoice_from_channelmanager
+/// let known_payment_hash = match channel_manager.create_inbound_payment(
+///     Some(10_000_000), 3600, None
+/// ) {
+///     Ok((payment_hash, _payment_secret)) => {
+///         println!("Creating inbound payment {}", payment_hash);
+///         payment_hash
+///     },
+///     Err(()) => panic!("Error creating inbound payment"),
+/// };
+///
+/// // On the event processing thread
+/// channel_manager.process_pending_events(&|event| match event {
+///     Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose {
+///         PaymentPurpose::InvoicePayment { payment_preimage: Some(payment_preimage), .. } => {
+///             assert_eq!(payment_hash, known_payment_hash);
+///             println!("Claiming payment {}", payment_hash);
+///             channel_manager.claim_funds(payment_preimage);
+///         },
+///         PaymentPurpose::InvoicePayment { payment_preimage: None, .. } => {
+///             println!("Unknown payment hash: {}", payment_hash);
+///         },
+///         PaymentPurpose::SpontaneousPayment(payment_preimage) => {
+///             assert_ne!(payment_hash, known_payment_hash);
+///             println!("Claiming spontaneous payment {}", payment_hash);
+///             channel_manager.claim_funds(payment_preimage);
+///         },
+///     },
+///     Event::PaymentClaimed { payment_hash, amount_msat, .. } => {
+///         assert_eq!(payment_hash, known_payment_hash);
+///         println!("Claimed {} msats", amount_msat);
+///     },
+///     // ...
+/// #     _ => {},
+/// });
+/// # }
+/// ```
+///
+/// For paying an invoice, [`lightning-invoice`] provides a `payment` module with convenience
+/// functions for use with [`send_payment`].
+///
+/// ```
+/// # use lightning::events::{Event, EventsProvider};
+/// # use lightning::ln::PaymentHash;
+/// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, RecipientOnionFields, Retry};
+/// # use lightning::routing::router::RouteParameters;
+/// #
+/// # fn example<T: AChannelManager>(
+/// #     channel_manager: T, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
+/// #     route_params: RouteParameters, retry: Retry
+/// # ) {
+/// # let channel_manager = channel_manager.get_cm();
+/// // let (payment_hash, recipient_onion, route_params) =
+/// //     payment::payment_parameters_from_invoice(&invoice);
+/// let payment_id = PaymentId([42; 32]);
+/// match channel_manager.send_payment(
+///     payment_hash, recipient_onion, payment_id, route_params, retry
+/// ) {
+///     Ok(()) => println!("Sending payment with hash {}", payment_hash),
+///     Err(e) => println!("Failed sending payment with hash {}: {:?}", payment_hash, e),
+/// }
+///
+/// let expected_payment_id = payment_id;
+/// let expected_payment_hash = payment_hash;
+/// assert!(
+///     channel_manager.list_recent_payments().iter().find(|details| matches!(
+///         details,
+///         RecentPaymentDetails::Pending {
+///             payment_id: expected_payment_id,
+///             payment_hash: expected_payment_hash,
+///             ..
+///         }
+///     )).is_some()
+/// );
+///
+/// // On the event processing thread
+/// channel_manager.process_pending_events(&|event| match event {
+///     Event::PaymentSent { payment_hash, .. } => println!("Paid {}", payment_hash),
+///     Event::PaymentFailed { payment_hash, .. } => println!("Failed paying {}", payment_hash),
+///     // ...
+/// #     _ => {},
+/// });
+/// # }
+/// ```
+///
+/// # Persistence
 ///
 /// Implements [`Writeable`] to write out all channel state to disk. Implies [`peer_disconnected`] for
 /// all peers during write/read (though does not modify this instance, only the instance being
@@ -1101,12 +1547,16 @@ where
 /// tells you the last block hash which was connected. You should get the best block tip before using the manager.
 /// See [`chain::Listen`] and [`chain::Confirm`] for more details.
 ///
+/// # `ChannelUpdate` Messages
+///
 /// Note that `ChannelManager` is responsible for tracking liveness of its channels and generating
 /// [`ChannelUpdate`] messages informing peers that the channel is temporarily disabled. To avoid
 /// spam due to quick disconnection/reconnection, updates are not sent until the channel has been
 /// offline for a full minute. In order to track this, you must call
 /// [`timer_tick_occurred`] roughly once per minute, though it doesn't have to be perfect.
 ///
+/// # DoS Mitigation
+///
 /// To avoid trivial DoS issues, `ChannelManager` limits the number of inbound connections and
 /// inbound channels without confirmed funding transactions. This may result in nodes which we do
 /// not have a channel with being unable to connect to us or open new channels with us if we have
@@ -1116,19 +1566,47 @@ where
 /// exempted from the count of unfunded channels. Similarly, outbound channels and connections are
 /// never limited. Please ensure you limit the count of such channels yourself.
 ///
+/// # Type Aliases
+///
 /// Rather than using a plain `ChannelManager`, it is preferable to use either a [`SimpleArcChannelManager`]
 /// a [`SimpleRefChannelManager`], for conciseness. See their documentation for more details, but
 /// essentially you should default to using a [`SimpleRefChannelManager`], and use a
 /// [`SimpleArcChannelManager`] when you require a `ChannelManager` with a static lifetime, such as when
 /// you're using lightning-net-tokio.
 ///
+/// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
+/// [`MessageHandler`]: crate::ln::peer_handler::MessageHandler
+/// [`OnionMessenger`]: crate::onion_message::messenger::OnionMessenger
+/// [`PeerManager::read_event`]: crate::ln::peer_handler::PeerManager::read_event
+/// [`PeerManager::process_events`]: crate::ln::peer_handler::PeerManager::process_events
+/// [`timer_tick_occurred`]: Self::timer_tick_occurred
+/// [`get_and_clear_needs_persistence`]: Self::get_and_clear_needs_persistence
+/// [`Persister`]: crate::util::persist::Persister
+/// [`KVStore`]: crate::util::persist::KVStore
+/// [`get_event_or_persistence_needed_future`]: Self::get_event_or_persistence_needed_future
+/// [`lightning-block-sync`]: https://docs.rs/lightning_block_sync/latest/lightning_block_sync
+/// [`lightning-transaction-sync`]: https://docs.rs/lightning_transaction_sync/latest/lightning_transaction_sync
+/// [`lightning-background-processor`]: https://docs.rs/lightning_background_processor/lightning_background_processor
+/// [`list_channels`]: Self::list_channels
+/// [`list_usable_channels`]: Self::list_usable_channels
+/// [`create_channel`]: Self::create_channel
+/// [`close_channel`]: Self::force_close_broadcasting_latest_txn
+/// [`force_close_broadcasting_latest_txn`]: Self::force_close_broadcasting_latest_txn
+/// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
+/// [BOLT 12]: https://github.com/rustyrussell/lightning-rfc/blob/guilt/offers/12-offer-encoding.md
+/// [`list_recent_payments`]: Self::list_recent_payments
+/// [`abandon_payment`]: Self::abandon_payment
+/// [`lightning-invoice`]: https://docs.rs/lightning_invoice/latest/lightning_invoice
+/// [`create_inbound_payment`]: Self::create_inbound_payment
+/// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
+/// [`claim_funds`]: Self::claim_funds
+/// [`send_payment`]: Self::send_payment
 /// [`peer_disconnected`]: msgs::ChannelMessageHandler::peer_disconnected
 /// [`funding_created`]: msgs::FundingCreated
 /// [`funding_transaction_generated`]: Self::funding_transaction_generated
 /// [`BlockHash`]: bitcoin::hash_types::BlockHash
 /// [`update_channel`]: chain::Watch::update_channel
 /// [`ChannelUpdate`]: msgs::ChannelUpdate
-/// [`timer_tick_occurred`]: Self::timer_tick_occurred
 /// [`read`]: ReadableArgs::read
 //
 // Lock order:
@@ -1625,9 +2103,6 @@ pub struct ChannelDetails {
        pub counterparty: ChannelCounterparty,
        /// The Channel's funding transaction output, if we've negotiated the funding transaction with
        /// our counterparty already.
-       ///
-       /// Note that, if this has been set, `channel_id` will be equivalent to
-       /// `funding_txo.unwrap().to_channel_id()`.
        pub funding_txo: Option<OutPoint>,
        /// The features which this channel operates with. See individual features for more info.
        ///
@@ -1793,6 +2268,14 @@ pub struct ChannelDetails {
        ///
        /// This field is only `None` for `ChannelDetails` objects serialized prior to LDK 0.0.109.
        pub config: Option<ChannelConfig>,
+       /// Pending inbound HTLCs.
+       ///
+       /// This field is empty for objects serialized with LDK versions prior to 0.0.122.
+       pub pending_inbound_htlcs: Vec<InboundHTLCDetails>,
+       /// Pending outbound HTLCs.
+       ///
+       /// This field is empty for objects serialized with LDK versions prior to 0.0.122.
+       pub pending_outbound_htlcs: Vec<OutboundHTLCDetails>,
 }
 
 impl ChannelDetails {
@@ -1870,6 +2353,8 @@ impl ChannelDetails {
                        inbound_htlc_maximum_msat: context.get_holder_htlc_maximum_msat(),
                        config: Some(context.config()),
                        channel_shutdown_state: Some(context.shutdown_state()),
+                       pending_inbound_htlcs: context.get_pending_inbound_htlc_details(),
+                       pending_outbound_htlcs: context.get_pending_outbound_htlc_details(),
                }
        }
 }
@@ -2069,6 +2554,14 @@ macro_rules! convert_chan_phase_err {
                        ChannelPhase::UnfundedInboundV1(channel) => {
                                convert_chan_phase_err!($self, $err, channel, $channel_id, UNFUNDED_CHANNEL)
                        },
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedOutboundV2(channel) => {
+                               convert_chan_phase_err!($self, $err, channel, $channel_id, UNFUNDED_CHANNEL)
+                       },
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedInboundV2(channel) => {
+                               convert_chan_phase_err!($self, $err, channel, $channel_id, UNFUNDED_CHANNEL)
+                       },
                }
        };
 }
@@ -2144,6 +2637,7 @@ macro_rules! emit_channel_pending_event {
                                counterparty_node_id: $channel.context.get_counterparty_node_id(),
                                user_channel_id: $channel.context.get_user_id(),
                                funding_txo: $channel.context.get_funding_txo().unwrap().into_bitcoin_outpoint(),
+                               channel_type: Some($channel.context.get_channel_type().clone()),
                        }, None));
                        $channel.context.set_channel_pending_event_emitted();
                }
@@ -2170,7 +2664,7 @@ macro_rules! handle_monitor_update_completion {
                let logger = WithChannelContext::from(&$self.logger, &$chan.context);
                let mut updates = $chan.monitor_updating_restored(&&logger,
                        &$self.node_signer, $self.chain_hash, &$self.default_configuration,
-                       $self.best_block.read().unwrap().height());
+                       $self.best_block.read().unwrap().height);
                let counterparty_node_id = $chan.context.get_counterparty_node_id();
                let channel_update = if updates.channel_ready.is_some() && $chan.context.is_usable() {
                        // We only send a channel_update in the case where we are just now sending a
@@ -2424,14 +2918,14 @@ where
 
                        best_block: RwLock::new(params.best_block),
 
-                       outbound_scid_aliases: Mutex::new(HashSet::new()),
-                       pending_inbound_payments: Mutex::new(HashMap::new()),
+                       outbound_scid_aliases: Mutex::new(new_hash_set()),
+                       pending_inbound_payments: Mutex::new(new_hash_map()),
                        pending_outbound_payments: OutboundPayments::new(),
-                       forward_htlcs: Mutex::new(HashMap::new()),
-                       claimable_payments: Mutex::new(ClaimablePayments { claimable_payments: HashMap::new(), pending_claiming_payments: HashMap::new() }),
-                       pending_intercepted_htlcs: Mutex::new(HashMap::new()),
-                       outpoint_to_peer: Mutex::new(HashMap::new()),
-                       short_to_chan_info: FairRwLock::new(HashMap::new()),
+                       forward_htlcs: Mutex::new(new_hash_map()),
+                       claimable_payments: Mutex::new(ClaimablePayments { claimable_payments: new_hash_map(), pending_claiming_payments: new_hash_map() }),
+                       pending_intercepted_htlcs: Mutex::new(new_hash_map()),
+                       outpoint_to_peer: Mutex::new(new_hash_map()),
+                       short_to_chan_info: FairRwLock::new(new_hash_map()),
 
                        our_network_pubkey: node_signer.get_node_id(Recipient::Node).unwrap(),
                        secp_ctx,
@@ -2443,7 +2937,7 @@ where
 
                        highest_seen_timestamp: AtomicUsize::new(current_timestamp as usize),
 
-                       per_peer_state: FairRwLock::new(HashMap::new()),
+                       per_peer_state: FairRwLock::new(new_hash_map()),
 
                        pending_events: Mutex::new(VecDeque::new()),
                        pending_events_processor: AtomicBool::new(false),
@@ -2470,7 +2964,7 @@ where
        }
 
        fn create_and_insert_outbound_scid_alias(&self) -> u64 {
-               let height = self.best_block.read().unwrap().height();
+               let height = self.best_block.read().unwrap().height;
                let mut outbound_scid_alias = 0;
                let mut i = 0;
                loop {
@@ -2548,7 +3042,7 @@ where
                        let config = if override_config.is_some() { override_config.as_ref().unwrap() } else { &self.default_configuration };
                        match OutboundV1Channel::new(&self.fee_estimator, &self.entropy_source, &self.signer_provider, their_network_key,
                                their_features, channel_value_satoshis, push_msat, user_channel_id, config,
-                               self.best_block.read().unwrap().height(), outbound_scid_alias, temporary_channel_id)
+                               self.best_block.read().unwrap().height, outbound_scid_alias, temporary_channel_id)
                        {
                                Ok(res) => res,
                                Err(e) => {
@@ -2587,7 +3081,7 @@ where
                // the same channel.
                let mut res = Vec::with_capacity(self.short_to_chan_info.read().unwrap().len());
                {
-                       let best_block_height = self.best_block.read().unwrap().height();
+                       let best_block_height = self.best_block.read().unwrap().height;
                        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();
@@ -2620,7 +3114,7 @@ where
                // the same channel.
                let mut res = Vec::with_capacity(self.short_to_chan_info.read().unwrap().len());
                {
-                       let best_block_height = self.best_block.read().unwrap().height();
+                       let best_block_height = self.best_block.read().unwrap().height;
                        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();
@@ -2650,7 +3144,7 @@ where
 
        /// Gets the list of channels we have with a given counterparty, in random order.
        pub fn list_channels_with_counterparty(&self, counterparty_node_id: &PublicKey) -> Vec<ChannelDetails> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let per_peer_state = self.per_peer_state.read().unwrap();
 
                if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
@@ -2853,7 +3347,7 @@ where
                        let receiver = HTLCDestination::NextHopChannel { node_id: Some(counterparty_node_id), channel_id };
                        self.fail_htlc_backwards_internal(&source, &payment_hash, &reason, receiver);
                }
-               if let Some((_, funding_txo, monitor_update)) = shutdown_res.monitor_update {
+               if let Some((_, funding_txo, _channel_id, monitor_update)) = shutdown_res.monitor_update {
                        // There isn't anything we can do if we get an update failure - we're already
                        // force-closing. The monitor update on the required in-memory copy should broadcast
                        // the latest local state, which is the best we can do anyway. Thus, it is safe to
@@ -2934,6 +3428,13 @@ where
                                                // Unfunded channel has no update
                                                (None, chan_phase.context().get_counterparty_node_id())
                                        },
+                                       // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                                       #[cfg(dual_funding)]
+                                       ChannelPhase::UnfundedOutboundV2(_) | ChannelPhase::UnfundedInboundV2(_) => {
+                                               self.finish_close_channel(chan_phase.context_mut().force_shutdown(false, closure_reason));
+                                               // Unfunded channel has no update
+                                               (None, chan_phase.context().get_counterparty_node_id())
+                                       },
                                }
                        } else if peer_state.inbound_channel_request_by_id.remove(channel_id).is_some() {
                                log_error!(logger, "Force-closing channel {}", &channel_id);
@@ -2997,8 +3498,8 @@ where
        /// the latest local transaction(s). Fails if `channel_id` is unknown to the manager, or if the
        /// `counterparty_node_id` isn't the counterparty of the corresponding channel.
        ///
-       /// You can always get the latest local transaction(s) to broadcast from
-       /// [`ChannelMonitor::get_latest_holder_commitment_txn`].
+       /// You can always broadcast the latest local transaction(s) via
+       /// [`ChannelMonitor::broadcast_latest_holder_commitment_txn`].
        pub fn force_close_without_broadcasting_txn(&self, channel_id: &ChannelId, counterparty_node_id: &PublicKey)
        -> Result<(), APIError> {
                self.force_close_sending_error(channel_id, counterparty_node_id, false)
@@ -3153,7 +3654,7 @@ where
                                None
                        };
 
-                       let cur_height = self.best_block.read().unwrap().height() + 1;
+                       let cur_height = self.best_block.read().unwrap().height + 1;
 
                        if let Err((err_msg, code)) = check_incoming_htlc_cltv(
                                cur_height, outgoing_cltv_value, msg.cltv_expiry
@@ -3230,7 +3731,7 @@ where
                match decoded_hop {
                        onion_utils::Hop::Receive(next_hop_data) => {
                                // OUR PAYMENT!
-                               let current_height: u32 = self.best_block.read().unwrap().height();
+                               let current_height: u32 = self.best_block.read().unwrap().height;
                                match create_recv_pending_htlc_info(next_hop_data, shared_secret, msg.payment_hash,
                                        msg.amount_msat, msg.cltv_expiry, None, allow_underpay, msg.skimmed_fee_msat,
                                        current_height, self.default_configuration.accept_mpp_keysend)
@@ -3490,7 +3991,7 @@ where
        /// [`PeerManager::process_events`]: crate::ln::peer_handler::PeerManager::process_events
        /// [`ChannelMonitorUpdateStatus::InProgress`]: crate::chain::ChannelMonitorUpdateStatus::InProgress
        pub fn send_payment_with_route(&self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId) -> Result<(), PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               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,
@@ -3501,7 +4002,7 @@ where
        /// Similar to [`ChannelManager::send_payment_with_route`], but will automatically find a route based on
        /// `route_params` and retry failed payment paths based on `retry_strategy`.
        pub fn send_payment(&self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<(), RetryableSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments
                        .send_payment(payment_hash, recipient_onion, payment_id, retry_strategy, route_params,
@@ -3512,7 +4013,7 @@ where
 
        #[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 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,
@@ -3521,7 +4022,7 @@ where
 
        #[cfg(test)]
        pub(crate) fn test_add_new_pending_payment(&self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId, route: &Route) -> Result<Vec<[u8; 32]>, PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                self.pending_outbound_payments.test_add_new_pending_payment(payment_hash, recipient_onion, payment_id, route, None, &self.entropy_source, best_block_height)
        }
 
@@ -3531,7 +4032,7 @@ where
        }
 
        pub(super) fn send_payment_for_bolt12_invoice(&self, invoice: &Bolt12Invoice, payment_id: PaymentId) -> Result<(), Bolt12PaymentError> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments
                        .send_payment_for_bolt12_invoice(
@@ -3588,7 +4089,7 @@ where
        ///
        /// [`send_payment`]: Self::send_payment
        pub fn send_spontaneous_payment(&self, route: &Route, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields, payment_id: PaymentId) -> Result<PaymentHash, PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                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,
@@ -3603,7 +4104,7 @@ where
        ///
        /// [`PaymentParameters::for_keysend`]: crate::routing::router::PaymentParameters::for_keysend
        pub fn send_spontaneous_payment_with_retry(&self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<PaymentHash, RetryableSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.send_spontaneous_payment(payment_preimage, recipient_onion,
                        payment_id, retry_strategy, route_params, &self.router, self.list_usable_channels(),
@@ -3615,7 +4116,7 @@ where
        /// [`PaymentHash`] of probes based on a static secret and a random [`PaymentId`], which allows
        /// us to easily discern them from real payments.
        pub fn send_probe(&self, path: Path) -> Result<(PaymentHash, PaymentId), PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               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,
@@ -3677,7 +4178,7 @@ where
                                ProbeSendFailure::RouteNotFound
                        })?;
 
-               let mut used_liquidity_map = HashMap::with_capacity(first_hops.len());
+               let mut used_liquidity_map = hash_map_with_capacity(first_hops.len());
 
                let mut res = Vec::new();
 
@@ -3893,7 +4394,7 @@ where
                        }));
                }
                {
-                       let height = self.best_block.read().unwrap().height();
+                       let height = self.best_block.read().unwrap().height;
                        // Transactions are evaluated as final by network mempools if their locktime is strictly
                        // lower than the next block height. However, the modules constituting our Lightning
                        // node might not have perfect sync about their blockchain views. Thus, if the wallet
@@ -3952,7 +4453,10 @@ where
                                        }
                                        let outpoint = OutPoint { txid: tx.txid(), index: output_index.unwrap() };
                                        if let Some(funding_batch_state) = funding_batch_state.as_mut() {
-                                               funding_batch_state.push((outpoint.to_channel_id(), *counterparty_node_id, false));
+                                               // TODO(dual_funding): We only do batch funding for V1 channels at the moment, but we'll probably
+                                               // need to fix this somehow to not rely on using the outpoint for the channel ID if we
+                                               // want to support V2 batching here as well.
+                                               funding_batch_state.push((ChannelId::v1_from_funding_outpoint(outpoint), *counterparty_node_id, false));
                                        }
                                        Ok(outpoint)
                                })
@@ -4177,6 +4681,7 @@ where
                let mut per_source_pending_forward = [(
                        payment.prev_short_channel_id,
                        payment.prev_funding_outpoint,
+                       payment.prev_channel_id,
                        payment.prev_user_channel_id,
                        vec![(pending_htlc_info, payment.prev_htlc_id)]
                )];
@@ -4204,6 +4709,7 @@ where
                                short_channel_id: payment.prev_short_channel_id,
                                user_channel_id: Some(payment.prev_user_channel_id),
                                outpoint: payment.prev_funding_outpoint,
+                               channel_id: payment.prev_channel_id,
                                htlc_id: payment.prev_htlc_id,
                                incoming_packet_shared_secret: payment.forward_info.incoming_shared_secret,
                                phantom_shared_secret: None,
@@ -4227,9 +4733,9 @@ where
 
                let mut new_events = VecDeque::new();
                let mut failed_forwards = Vec::new();
-               let mut phantom_receives: Vec<(u64, OutPoint, u128, Vec<(PendingHTLCInfo, u64)>)> = Vec::new();
+               let mut phantom_receives: Vec<(u64, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)> = Vec::new();
                {
-                       let mut forward_htlcs = HashMap::new();
+                       let mut forward_htlcs = new_hash_map();
                        mem::swap(&mut forward_htlcs, &mut self.forward_htlcs.lock().unwrap());
 
                        for (short_chan_id, mut pending_forwards) in forward_htlcs {
@@ -4240,20 +4746,21 @@ where
                                                        for forward_info in pending_forwards.drain(..) {
                                                                match forward_info {
                                                                        HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
-                                                                               prev_short_channel_id, prev_htlc_id, prev_funding_outpoint, prev_user_channel_id,
-                                                                               forward_info: PendingHTLCInfo {
+                                                                               prev_short_channel_id, prev_htlc_id, prev_channel_id, prev_funding_outpoint,
+                                                                               prev_user_channel_id, forward_info: PendingHTLCInfo {
                                                                                        routing, incoming_shared_secret, payment_hash, outgoing_amt_msat,
                                                                                        outgoing_cltv_value, ..
                                                                                }
                                                                        }) => {
                                                                                macro_rules! failure_handler {
                                                                                        ($msg: expr, $err_code: expr, $err_data: expr, $phantom_ss: expr, $next_hop_unknown: expr) => {
-                                                                                               let logger = WithContext::from(&self.logger, forwarding_counterparty, Some(prev_funding_outpoint.to_channel_id()));
+                                                                                               let logger = WithContext::from(&self.logger, forwarding_counterparty, Some(prev_channel_id));
                                                                                                log_info!(logger, "Failed to accept/forward incoming HTLC: {}", $msg);
 
                                                                                                let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                                        short_channel_id: prev_short_channel_id,
                                                                                                        user_channel_id: Some(prev_user_channel_id),
+                                                                                                       channel_id: prev_channel_id,
                                                                                                        outpoint: prev_funding_outpoint,
                                                                                                        htlc_id: prev_htlc_id,
                                                                                                        incoming_packet_shared_secret: incoming_shared_secret,
@@ -4311,13 +4818,13 @@ where
                                                                                                };
                                                                                                match next_hop {
                                                                                                        onion_utils::Hop::Receive(hop_data) => {
-                                                                                                               let current_height: u32 = self.best_block.read().unwrap().height();
+                                                                                                               let current_height: u32 = self.best_block.read().unwrap().height;
                                                                                                                match create_recv_pending_htlc_info(hop_data,
                                                                                                                        incoming_shared_secret, payment_hash, outgoing_amt_msat,
                                                                                                                        outgoing_cltv_value, Some(phantom_shared_secret), false, None,
                                                                                                                        current_height, self.default_configuration.accept_mpp_keysend)
                                                                                                                {
-                                                                                                                       Ok(info) => phantom_receives.push((prev_short_channel_id, prev_funding_outpoint, prev_user_channel_id, vec![(info, prev_htlc_id)])),
+                                                                                                                       Ok(info) => phantom_receives.push((prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_user_channel_id, vec![(info, prev_htlc_id)])),
                                                                                                                        Err(InboundHTLCErr { err_code, err_data, msg }) => failed_payment!(msg, err_code, err_data, Some(phantom_shared_secret))
                                                                                                                }
                                                                                                        },
@@ -4362,8 +4869,8 @@ where
                                                for forward_info in pending_forwards.drain(..) {
                                                        let queue_fail_htlc_res = match forward_info {
                                                                HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
-                                                                       prev_short_channel_id, prev_htlc_id, prev_funding_outpoint, prev_user_channel_id,
-                                                                       forward_info: PendingHTLCInfo {
+                                                                       prev_short_channel_id, prev_htlc_id, prev_channel_id, prev_funding_outpoint,
+                                                                       prev_user_channel_id, forward_info: PendingHTLCInfo {
                                                                                incoming_shared_secret, payment_hash, outgoing_amt_msat, outgoing_cltv_value,
                                                                                routing: PendingHTLCRouting::Forward {
                                                                                        onion_packet, blinded, ..
@@ -4374,6 +4881,7 @@ where
                                                                        let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                short_channel_id: prev_short_channel_id,
                                                                                user_channel_id: Some(prev_user_channel_id),
+                                                                               channel_id: prev_channel_id,
                                                                                outpoint: prev_funding_outpoint,
                                                                                htlc_id: prev_htlc_id,
                                                                                incoming_packet_shared_secret: incoming_shared_secret,
@@ -4445,8 +4953,8 @@ where
                                        'next_forwardable_htlc: for forward_info in pending_forwards.drain(..) {
                                                match forward_info {
                                                        HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
-                                                               prev_short_channel_id, prev_htlc_id, prev_funding_outpoint, prev_user_channel_id,
-                                                               forward_info: PendingHTLCInfo {
+                                                               prev_short_channel_id, prev_htlc_id, prev_channel_id, prev_funding_outpoint,
+                                                               prev_user_channel_id, forward_info: PendingHTLCInfo {
                                                                        routing, incoming_shared_secret, payment_hash, incoming_amt_msat, outgoing_amt_msat,
                                                                        skimmed_fee_msat, ..
                                                                }
@@ -4463,7 +4971,10 @@ where
                                                                                (incoming_cltv_expiry, OnionPayload::Invoice { _legacy_hop_data },
                                                                                        Some(payment_data), phantom_shared_secret, onion_fields)
                                                                        },
-                                                                       PendingHTLCRouting::ReceiveKeysend { payment_data, payment_preimage, payment_metadata, incoming_cltv_expiry, custom_tlvs } => {
+                                                                       PendingHTLCRouting::ReceiveKeysend {
+                                                                               payment_data, payment_preimage, payment_metadata,
+                                                                               incoming_cltv_expiry, custom_tlvs, requires_blinded_error: _
+                                                                       } => {
                                                                                let onion_fields = RecipientOnionFields {
                                                                                        payment_secret: payment_data.as_ref().map(|data| data.payment_secret),
                                                                                        payment_metadata,
@@ -4480,6 +4991,7 @@ where
                                                                        prev_hop: HTLCPreviousHopData {
                                                                                short_channel_id: prev_short_channel_id,
                                                                                user_channel_id: Some(prev_user_channel_id),
+                                                                               channel_id: prev_channel_id,
                                                                                outpoint: prev_funding_outpoint,
                                                                                htlc_id: prev_htlc_id,
                                                                                incoming_packet_shared_secret: incoming_shared_secret,
@@ -4506,11 +5018,12 @@ where
                                                                                debug_assert!(!committed_to_claimable);
                                                                                let mut htlc_msat_height_data = $htlc.value.to_be_bytes().to_vec();
                                                                                htlc_msat_height_data.extend_from_slice(
-                                                                                       &self.best_block.read().unwrap().height().to_be_bytes(),
+                                                                                       &self.best_block.read().unwrap().height.to_be_bytes(),
                                                                                );
                                                                                failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                                short_channel_id: $htlc.prev_hop.short_channel_id,
                                                                                                user_channel_id: $htlc.prev_hop.user_channel_id,
+                                                                                               channel_id: prev_channel_id,
                                                                                                outpoint: prev_funding_outpoint,
                                                                                                htlc_id: $htlc.prev_hop.htlc_id,
                                                                                                incoming_packet_shared_secret: $htlc.prev_hop.incoming_packet_shared_secret,
@@ -4591,7 +5104,6 @@ where
                                                                                        #[allow(unused_assignments)] {
                                                                                                committed_to_claimable = true;
                                                                                        }
-                                                                                       let prev_channel_id = prev_funding_outpoint.to_channel_id();
                                                                                        htlcs.push(claimable_htlc);
                                                                                        let amount_msat = htlcs.iter().map(|htlc| htlc.value).sum();
                                                                                        htlcs.iter_mut().for_each(|htlc| htlc.total_value_received = Some(amount_msat));
@@ -4644,7 +5156,7 @@ where
                                                                                                        }
                                                                                                };
                                                                                                if let Some(min_final_cltv_expiry_delta) = min_final_cltv_expiry_delta {
-                                                                                                       let expected_min_expiry_height = (self.current_best_block().height() + min_final_cltv_expiry_delta as u32) as u64;
+                                                                                                       let expected_min_expiry_height = (self.current_best_block().height + min_final_cltv_expiry_delta as u32) as u64;
                                                                                                        if (cltv_expiry as u64) < expected_min_expiry_height {
                                                                                                                log_trace!(self.logger, "Failing new HTLC with payment_hash {} as its CLTV expiry was too soon (had {}, earliest expected {})",
                                                                                                                        &payment_hash, cltv_expiry, expected_min_expiry_height);
@@ -4698,7 +5210,7 @@ where
                        }
                }
 
-               let best_block_height = self.best_block.read().unwrap().height();
+               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, |args| self.send_payment_along_path(args));
@@ -4735,19 +5247,19 @@ where
 
                for event in background_events.drain(..) {
                        match event {
-                               BackgroundEvent::ClosedMonitorUpdateRegeneratedOnStartup((funding_txo, update)) => {
+                               BackgroundEvent::ClosedMonitorUpdateRegeneratedOnStartup((funding_txo, _channel_id, update)) => {
                                        // The channel has already been closed, so no use bothering to care about the
                                        // monitor updating completing.
                                        let _ = self.chain_monitor.update_channel(funding_txo, &update);
                                },
-                               BackgroundEvent::MonitorUpdateRegeneratedOnStartup { counterparty_node_id, funding_txo, update } => {
+                               BackgroundEvent::MonitorUpdateRegeneratedOnStartup { counterparty_node_id, funding_txo, channel_id, update } => {
                                        let mut updated_chan = false;
                                        {
                                                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;
-                                                       match peer_state.channel_by_id.entry(funding_txo.to_channel_id()) {
+                                                       match peer_state.channel_by_id.entry(channel_id) {
                                                                hash_map::Entry::Occupied(mut chan_phase) => {
                                                                        if let ChannelPhase::Funded(chan) = chan_phase.get_mut() {
                                                                                updated_chan = true;
@@ -4801,10 +5313,6 @@ where
 
                // If the feerate has decreased by less than half, don't bother
                if new_feerate <= chan.context.get_feerate_sat_per_1000_weight() && new_feerate * 2 > chan.context.get_feerate_sat_per_1000_weight() {
-                       if new_feerate != chan.context.get_feerate_sat_per_1000_weight() {
-                               log_trace!(logger, "Channel {} does not qualify for a feerate change from {} to {}.",
-                               chan_id, chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
-                       }
                        return NotifyOption::SkipPersistNoEvents;
                }
                if !chan.context.is_live() {
@@ -5003,6 +5511,16 @@ where
                                                                process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context,
                                                                        pending_msg_events, counterparty_node_id)
                                                        },
+                                                       #[cfg(dual_funding)]
+                                                       ChannelPhase::UnfundedInboundV2(chan) => {
+                                                               process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context,
+                                                                       pending_msg_events, counterparty_node_id)
+                                                       },
+                                                       #[cfg(dual_funding)]
+                                                       ChannelPhase::UnfundedOutboundV2(chan) => {
+                                                               process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context,
+                                                                       pending_msg_events, counterparty_node_id)
+                                                       },
                                                }
                                        });
 
@@ -5163,7 +5681,7 @@ where
                        FailureCode::RequiredNodeFeatureMissing => HTLCFailReason::from_failure_code(failure_code.into()),
                        FailureCode::IncorrectOrUnknownPaymentDetails => {
                                let mut htlc_msat_height_data = htlc.value.to_be_bytes().to_vec();
-                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height().to_be_bytes());
+                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height.to_be_bytes());
                                HTLCFailReason::reason(failure_code.into(), htlc_msat_height_data)
                        },
                        FailureCode::InvalidOnionPayload(data) => {
@@ -5286,10 +5804,10 @@ where
                        },
                        HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                ref short_channel_id, ref htlc_id, ref incoming_packet_shared_secret,
-                               ref phantom_shared_secret, ref outpoint, ref blinded_failure, ..
+                               ref phantom_shared_secret, outpoint: _, ref blinded_failure, ref channel_id, ..
                        }) => {
                                log_trace!(
-                                       WithContext::from(&self.logger, None, Some(outpoint.to_channel_id())),
+                                       WithContext::from(&self.logger, None, Some(*channel_id)),
                                        "Failing {}HTLC with payment_hash {} backwards from us: {:?}",
                                        if blinded_failure.is_some() { "blinded " } else { "" }, &payment_hash, onion_error
                                );
@@ -5333,7 +5851,7 @@ where
                                if push_forward_ev { self.push_pending_forwards_ev(); }
                                let mut pending_events = self.pending_events.lock().unwrap();
                                pending_events.push_back((events::Event::HTLCHandlingFailed {
-                                       prev_channel_id: outpoint.to_channel_id(),
+                                       prev_channel_id: *channel_id,
                                        failed_next_destination: destination,
                                }, None));
                        },
@@ -5474,7 +5992,7 @@ where
                }
                if valid_mpp {
                        for htlc in sources.drain(..) {
-                               let prev_hop_chan_id = htlc.prev_hop.outpoint.to_channel_id();
+                               let prev_hop_chan_id = htlc.prev_hop.channel_id;
                                if let Err((pk, err)) = self.claim_funds_from_hop(
                                        htlc.prev_hop, payment_preimage,
                                        |_, definitely_duplicate| {
@@ -5494,7 +6012,7 @@ where
                if !valid_mpp {
                        for htlc in sources.drain(..) {
                                let mut htlc_msat_height_data = htlc.value.to_be_bytes().to_vec();
-                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height().to_be_bytes());
+                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height.to_be_bytes());
                                let source = HTLCSource::PreviousHopData(htlc.prev_hop);
                                let reason = HTLCFailReason::reason(0x4000 | 15, htlc_msat_height_data);
                                let receiver = HTLCDestination::FailedPayment { payment_hash };
@@ -5527,7 +6045,7 @@ where
 
                {
                        let per_peer_state = self.per_peer_state.read().unwrap();
-                       let chan_id = prev_hop.outpoint.to_channel_id();
+                       let chan_id = prev_hop.channel_id;
                        let counterparty_node_id_opt = match self.short_to_chan_info.read().unwrap().get(&prev_hop.short_channel_id) {
                                Some((cp_id, _dup_chan_id)) => Some(cp_id.clone()),
                                None => None
@@ -5565,6 +6083,7 @@ where
                                                                                BackgroundEvent::MonitorUpdateRegeneratedOnStartup {
                                                                                        counterparty_node_id,
                                                                                        funding_txo: prev_hop.outpoint,
+                                                                                       channel_id: prev_hop.channel_id,
                                                                                        update: monitor_update.clone(),
                                                                                });
                                                                }
@@ -5579,13 +6098,13 @@ where
 
                                                                log_trace!(logger, "Completing monitor update completion action for channel {} as claim was redundant: {:?}",
                                                                        chan_id, action);
-                                                               let (node_id, funding_outpoint, blocker) =
+                                                               let (node_id, _funding_outpoint, channel_id, blocker) =
                                                                if let MonitorUpdateCompletionAction::FreeOtherChannelImmediately {
                                                                        downstream_counterparty_node_id: node_id,
                                                                        downstream_funding_outpoint: funding_outpoint,
-                                                                       blocking_action: blocker,
+                                                                       blocking_action: blocker, downstream_channel_id: channel_id,
                                                                } = action {
-                                                                       (node_id, funding_outpoint, blocker)
+                                                                       (node_id, funding_outpoint, channel_id, blocker)
                                                                } else {
                                                                        debug_assert!(false,
                                                                                "Duplicate claims should always free another channel immediately");
@@ -5595,7 +6114,7 @@ where
                                                                        let mut peer_state = peer_state_mtx.lock().unwrap();
                                                                        if let Some(blockers) = peer_state
                                                                                .actions_blocking_raa_monitor_updates
-                                                                               .get_mut(&funding_outpoint.to_channel_id())
+                                                                               .get_mut(&channel_id)
                                                                        {
                                                                                let mut found_blocker = false;
                                                                                blockers.retain(|iter| {
@@ -5624,6 +6143,7 @@ where
                        updates: vec![ChannelMonitorUpdateStep::PaymentPreimage {
                                payment_preimage,
                        }],
+                       channel_id: Some(prev_hop.channel_id),
                };
 
                if !during_init {
@@ -5635,7 +6155,8 @@ where
                                // with a preimage we *must* somehow manage to propagate it to the upstream
                                // channel, or we must have an ability to receive the same event and try
                                // again on restart.
-                               log_error!(WithContext::from(&self.logger, None, Some(prev_hop.outpoint.to_channel_id())), "Critical error: failed to update channel monitor with preimage {:?}: {:?}",
+                               log_error!(WithContext::from(&self.logger, None, Some(prev_hop.channel_id)),
+                                       "Critical error: failed to update channel monitor with preimage {:?}: {:?}",
                                        payment_preimage, update_res);
                        }
                } else {
@@ -5651,7 +6172,7 @@ where
                        // complete the monitor update completion action from `completion_action`.
                        self.pending_background_events.lock().unwrap().push(
                                BackgroundEvent::ClosedMonitorUpdateRegeneratedOnStartup((
-                                       prev_hop.outpoint, preimage_update,
+                                       prev_hop.outpoint, prev_hop.channel_id, preimage_update,
                                )));
                }
                // Note that we do process the completion action here. This totally could be a
@@ -5668,8 +6189,9 @@ where
        }
 
        fn claim_funds_internal(&self, source: HTLCSource, payment_preimage: PaymentPreimage,
-               forwarded_htlc_value_msat: Option<u64>, from_onchain: bool, startup_replay: bool,
-               next_channel_counterparty_node_id: Option<PublicKey>, next_channel_outpoint: OutPoint
+               forwarded_htlc_value_msat: Option<u64>, skimmed_fee_msat: Option<u64>, from_onchain: bool,
+               startup_replay: bool, next_channel_counterparty_node_id: Option<PublicKey>,
+               next_channel_outpoint: OutPoint, next_channel_id: ChannelId, next_user_channel_id: Option<u128>,
        ) {
                match source {
                        HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } => {
@@ -5679,7 +6201,7 @@ where
                                        debug_assert_eq!(pubkey, path.hops[0].pubkey);
                                }
                                let ev_completion_action = EventCompletionAction::ReleaseRAAChannelMonitorUpdate {
-                                       channel_funding_outpoint: next_channel_outpoint,
+                                       channel_funding_outpoint: next_channel_outpoint, channel_id: next_channel_id,
                                        counterparty_node_id: path.hops[0].pubkey,
                                };
                                self.pending_outbound_payments.claim_htlc(payment_id, payment_preimage,
@@ -5687,7 +6209,8 @@ where
                                        &self.logger);
                        },
                        HTLCSource::PreviousHopData(hop_data) => {
-                               let prev_outpoint = hop_data.outpoint;
+                               let prev_channel_id = hop_data.channel_id;
+                               let prev_user_channel_id = hop_data.user_channel_id;
                                let completed_blocker = RAAMonitorUpdateBlockingAction::from_prev_hop_data(&hop_data);
                                #[cfg(debug_assertions)]
                                let claiming_chan_funding_outpoint = hop_data.outpoint;
@@ -5695,7 +6218,7 @@ where
                                        |htlc_claim_value_msat, definitely_duplicate| {
                                                let chan_to_release =
                                                        if let Some(node_id) = next_channel_counterparty_node_id {
-                                                               Some((node_id, next_channel_outpoint, completed_blocker))
+                                                               Some((node_id, next_channel_outpoint, next_channel_id, completed_blocker))
                                                        } else {
                                                                // We can only get `None` here if we are processing a
                                                                // `ChannelMonitor`-originated event, in which case we
@@ -5732,7 +6255,7 @@ where
                                                                                },
                                                                                // or the channel we'd unblock is already closed,
                                                                                BackgroundEvent::ClosedMonitorUpdateRegeneratedOnStartup(
-                                                                                       (funding_txo, monitor_update)
+                                                                                       (funding_txo, _channel_id, monitor_update)
                                                                                ) => {
                                                                                        if *funding_txo == next_channel_outpoint {
                                                                                                assert_eq!(monitor_update.updates.len(), 1);
@@ -5748,7 +6271,7 @@ where
                                                                                BackgroundEvent::MonitorUpdatesComplete {
                                                                                        channel_id, ..
                                                                                } =>
-                                                                                       *channel_id == claiming_chan_funding_outpoint.to_channel_id(),
+                                                                                       *channel_id == prev_channel_id,
                                                                        }
                                                                }), "{:?}", *background_events);
                                                        }
@@ -5758,21 +6281,27 @@ where
                                                                Some(MonitorUpdateCompletionAction::FreeOtherChannelImmediately {
                                                                        downstream_counterparty_node_id: other_chan.0,
                                                                        downstream_funding_outpoint: other_chan.1,
-                                                                       blocking_action: other_chan.2,
+                                                                       downstream_channel_id: other_chan.2,
+                                                                       blocking_action: other_chan.3,
                                                                })
                                                        } else { None }
                                                } else {
-                                                       let fee_earned_msat = if let Some(forwarded_htlc_value) = forwarded_htlc_value_msat {
+                                                       let total_fee_earned_msat = if let Some(forwarded_htlc_value) = forwarded_htlc_value_msat {
                                                                if let Some(claimed_htlc_value) = htlc_claim_value_msat {
                                                                        Some(claimed_htlc_value - forwarded_htlc_value)
                                                                } else { None }
                                                        } else { None };
+                                                       debug_assert!(skimmed_fee_msat <= total_fee_earned_msat,
+                                                               "skimmed_fee_msat must always be included in total_fee_earned_msat");
                                                        Some(MonitorUpdateCompletionAction::EmitEventAndFreeOtherChannel {
                                                                event: events::Event::PaymentForwarded {
-                                                                       fee_earned_msat,
+                                                                       prev_channel_id: Some(prev_channel_id),
+                                                                       next_channel_id: Some(next_channel_id),
+                                                                       prev_user_channel_id,
+                                                                       next_user_channel_id,
+                                                                       total_fee_earned_msat,
+                                                                       skimmed_fee_msat,
                                                                        claim_from_onchain_tx: from_onchain,
-                                                                       prev_channel_id: Some(prev_outpoint.to_channel_id()),
-                                                                       next_channel_id: Some(next_channel_outpoint.to_channel_id()),
                                                                        outbound_amount_forwarded_msat: forwarded_htlc_value_msat,
                                                                },
                                                                downstream_counterparty_and_funding_outpoint: chan_to_release,
@@ -5822,16 +6351,17 @@ where
                                        event, downstream_counterparty_and_funding_outpoint
                                } => {
                                        self.pending_events.lock().unwrap().push_back((event, None));
-                                       if let Some((node_id, funding_outpoint, blocker)) = downstream_counterparty_and_funding_outpoint {
-                                               self.handle_monitor_update_release(node_id, funding_outpoint, Some(blocker));
+                                       if let Some((node_id, funding_outpoint, channel_id, blocker)) = downstream_counterparty_and_funding_outpoint {
+                                               self.handle_monitor_update_release(node_id, funding_outpoint, channel_id, Some(blocker));
                                        }
                                },
                                MonitorUpdateCompletionAction::FreeOtherChannelImmediately {
-                                       downstream_counterparty_node_id, downstream_funding_outpoint, blocking_action,
+                                       downstream_counterparty_node_id, downstream_funding_outpoint, downstream_channel_id, blocking_action,
                                } => {
                                        self.handle_monitor_update_release(
                                                downstream_counterparty_node_id,
                                                downstream_funding_outpoint,
+                                               downstream_channel_id,
                                                Some(blocking_action),
                                        );
                                },
@@ -5846,7 +6376,7 @@ where
                commitment_update: Option<msgs::CommitmentUpdate>, order: RAACommitmentOrder,
                pending_forwards: Vec<(PendingHTLCInfo, u64)>, funding_broadcastable: Option<Transaction>,
                channel_ready: Option<msgs::ChannelReady>, announcement_sigs: Option<msgs::AnnouncementSignatures>)
-       -> Option<(u64, OutPoint, u128, Vec<(PendingHTLCInfo, u64)>)> {
+       -> Option<(u64, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)> {
                let logger = WithChannelContext::from(&self.logger, &channel.context);
                log_trace!(logger, "Handling channel resumption for channel {} with {} RAA, {} commitment update, {} pending forwards, {}broadcasting funding, {} channel ready, {} announcement",
                        &channel.context.channel_id(),
@@ -5861,7 +6391,7 @@ where
                let counterparty_node_id = channel.context.get_counterparty_node_id();
                if !pending_forwards.is_empty() {
                        htlc_forwards = Some((channel.context.get_short_channel_id().unwrap_or(channel.context.outbound_scid_alias()),
-                               channel.context.get_funding_txo().unwrap(), channel.context.get_user_id(), pending_forwards));
+                               channel.context.get_funding_txo().unwrap(), channel.context.channel_id(), channel.context.get_user_id(), pending_forwards));
                }
 
                if let Some(msg) = channel_ready {
@@ -5915,7 +6445,7 @@ where
                htlc_forwards
        }
 
-       fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64, counterparty_node_id: Option<&PublicKey>) {
+       fn channel_monitor_updated(&self, funding_txo: &OutPoint, channel_id: &ChannelId, highest_applied_update_id: u64, counterparty_node_id: Option<&PublicKey>) {
                debug_assert!(self.total_consistency_lock.try_write().is_err()); // Caller holds read lock
 
                let counterparty_node_id = match counterparty_node_id {
@@ -5924,7 +6454,7 @@ where
                                // TODO: Once we can rely on the counterparty_node_id from the
                                // monitor event, this and the outpoint_to_peer map should be removed.
                                let outpoint_to_peer = self.outpoint_to_peer.lock().unwrap();
-                               match outpoint_to_peer.get(&funding_txo) {
+                               match outpoint_to_peer.get(funding_txo) {
                                        Some(cp_id) => cp_id.clone(),
                                        None => return,
                                }
@@ -5937,11 +6467,11 @@ where
                peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
                let peer_state = &mut *peer_state_lock;
                let channel =
-                       if let Some(ChannelPhase::Funded(chan)) = peer_state.channel_by_id.get_mut(&funding_txo.to_channel_id()) {
+                       if let Some(ChannelPhase::Funded(chan)) = peer_state.channel_by_id.get_mut(channel_id) {
                                chan
                        } else {
                                let update_actions = peer_state.monitor_update_blocked_actions
-                                       .remove(&funding_txo.to_channel_id()).unwrap_or(Vec::new());
+                                       .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);
@@ -6027,73 +6557,82 @@ where
                // happening and return an error. N.B. that we create channel with an outbound SCID of zero so
                // that we can delay allocating the SCID until after we're sure that the checks below will
                // succeed.
-               let mut channel = match peer_state.inbound_channel_request_by_id.remove(temporary_channel_id) {
+               let res = match peer_state.inbound_channel_request_by_id.remove(temporary_channel_id) {
                        Some(unaccepted_channel) => {
-                               let best_block_height = self.best_block.read().unwrap().height();
+                               let best_block_height = self.best_block.read().unwrap().height;
                                InboundV1Channel::new(&self.fee_estimator, &self.entropy_source, &self.signer_provider,
                                        counterparty_node_id.clone(), &self.channel_type_features(), &peer_state.latest_features,
                                        &unaccepted_channel.open_channel_msg, user_channel_id, &self.default_configuration, best_block_height,
-                                       &self.logger, accept_0conf).map_err(|e| {
-                                               let err_str = e.to_string();
-                                               log_error!(logger, "{}", err_str);
-
-                                               APIError::ChannelUnavailable { err: err_str }
-                                       })
-                               }
+                                       &self.logger, accept_0conf).map_err(|err| MsgHandleErrInternal::from_chan_no_close(err, *temporary_channel_id))
+                       },
                        _ => {
                                let err_str = "No such channel awaiting to be accepted.".to_owned();
                                log_error!(logger, "{}", err_str);
 
-                               Err(APIError::APIMisuseError { err: err_str })
+                               return Err(APIError::APIMisuseError { err: err_str });
                        }
-               }?;
+               };
 
-               if accept_0conf {
-                       // This should have been correctly configured by the call to InboundV1Channel::new.
-                       debug_assert!(channel.context.minimum_depth().unwrap() == 0);
-               } else if channel.context.get_channel_type().requires_zero_conf() {
-                       let send_msg_err_event = events::MessageSendEvent::HandleError {
-                               node_id: channel.context.get_counterparty_node_id(),
-                               action: msgs::ErrorAction::SendErrorMessage{
-                                       msg: msgs::ErrorMessage { channel_id: temporary_channel_id.clone(), data: "No zero confirmation channels accepted".to_owned(), }
+               match res {
+                       Err(err) => {
+                               mem::drop(peer_state_lock);
+                               mem::drop(per_peer_state);
+                               match handle_error!(self, Result::<(), MsgHandleErrInternal>::Err(err), *counterparty_node_id) {
+                                       Ok(_) => unreachable!("`handle_error` only returns Err as we've passed in an Err"),
+                                       Err(e) => {
+                                               return Err(APIError::ChannelUnavailable { err: e.err });
+                                       },
                                }
-                       };
-                       peer_state.pending_msg_events.push(send_msg_err_event);
-                       let err_str = "Please use accept_inbound_channel_from_trusted_peer_0conf to accept channels with zero confirmations.".to_owned();
-                       log_error!(logger, "{}", err_str);
+                       }
+                       Ok(mut channel) => {
+                               if accept_0conf {
+                                       // This should have been correctly configured by the call to InboundV1Channel::new.
+                                       debug_assert!(channel.context.minimum_depth().unwrap() == 0);
+                               } else if channel.context.get_channel_type().requires_zero_conf() {
+                                       let send_msg_err_event = events::MessageSendEvent::HandleError {
+                                               node_id: channel.context.get_counterparty_node_id(),
+                                               action: msgs::ErrorAction::SendErrorMessage{
+                                                       msg: msgs::ErrorMessage { channel_id: temporary_channel_id.clone(), data: "No zero confirmation channels accepted".to_owned(), }
+                                               }
+                                       };
+                                       peer_state.pending_msg_events.push(send_msg_err_event);
+                                       let err_str = "Please use accept_inbound_channel_from_trusted_peer_0conf to accept channels with zero confirmations.".to_owned();
+                                       log_error!(logger, "{}", err_str);
 
-                       return Err(APIError::APIMisuseError { err: err_str });
-               } else {
-                       // If this peer already has some channels, a new channel won't increase our number of peers
-                       // with unfunded channels, so as long as we aren't over the maximum number of unfunded
-                       // channels per-peer we can accept channels from a peer with existing ones.
-                       if is_only_peer_channel && peers_without_funded_channels >= MAX_UNFUNDED_CHANNEL_PEERS {
-                               let send_msg_err_event = events::MessageSendEvent::HandleError {
-                                       node_id: channel.context.get_counterparty_node_id(),
-                                       action: msgs::ErrorAction::SendErrorMessage{
-                                               msg: msgs::ErrorMessage { channel_id: temporary_channel_id.clone(), data: "Have too many peers with unfunded channels, not accepting new ones".to_owned(), }
-                                       }
-                               };
-                               peer_state.pending_msg_events.push(send_msg_err_event);
-                               let err_str = "Too many peers with unfunded channels, refusing to accept new ones".to_owned();
-                               log_error!(logger, "{}", err_str);
+                                       return Err(APIError::APIMisuseError { err: err_str });
+                               } else {
+                                       // If this peer already has some channels, a new channel won't increase our number of peers
+                                       // with unfunded channels, so as long as we aren't over the maximum number of unfunded
+                                       // channels per-peer we can accept channels from a peer with existing ones.
+                                       if is_only_peer_channel && peers_without_funded_channels >= MAX_UNFUNDED_CHANNEL_PEERS {
+                                               let send_msg_err_event = events::MessageSendEvent::HandleError {
+                                                       node_id: channel.context.get_counterparty_node_id(),
+                                                       action: msgs::ErrorAction::SendErrorMessage{
+                                                               msg: msgs::ErrorMessage { channel_id: temporary_channel_id.clone(), data: "Have too many peers with unfunded channels, not accepting new ones".to_owned(), }
+                                                       }
+                                               };
+                                               peer_state.pending_msg_events.push(send_msg_err_event);
+                                               let err_str = "Too many peers with unfunded channels, refusing to accept new ones".to_owned();
+                                               log_error!(logger, "{}", err_str);
 
-                               return Err(APIError::APIMisuseError { err: err_str });
-                       }
-               }
+                                               return Err(APIError::APIMisuseError { err: err_str });
+                                       }
+                               }
 
-               // Now that we know we have a channel, assign an outbound SCID alias.
-               let outbound_scid_alias = self.create_and_insert_outbound_scid_alias();
-               channel.context.set_outbound_scid_alias(outbound_scid_alias);
+                               // Now that we know we have a channel, assign an outbound SCID alias.
+                               let outbound_scid_alias = self.create_and_insert_outbound_scid_alias();
+                               channel.context.set_outbound_scid_alias(outbound_scid_alias);
 
-               peer_state.pending_msg_events.push(events::MessageSendEvent::SendAcceptChannel {
-                       node_id: channel.context.get_counterparty_node_id(),
-                       msg: channel.accept_inbound_channel(),
-               });
+                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendAcceptChannel {
+                                       node_id: channel.context.get_counterparty_node_id(),
+                                       msg: channel.accept_inbound_channel(),
+                               });
 
-               peer_state.channel_by_id.insert(temporary_channel_id.clone(), ChannelPhase::UnfundedInboundV1(channel));
+                               peer_state.channel_by_id.insert(temporary_channel_id.clone(), ChannelPhase::UnfundedInboundV1(channel));
 
-               Ok(())
+                               Ok(())
+                       },
+               }
        }
 
        /// Gets the number of peers which match the given filter and do not have any funded, outbound,
@@ -6104,7 +6643,7 @@ where
        fn peers_without_funded_channels<Filter>(&self, maybe_count_peer: Filter) -> usize
        where Filter: Fn(&PeerState<SP>) -> bool {
                let mut peers_without_funded_channels = 0;
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                {
                        let peer_state_lock = self.per_peer_state.read().unwrap();
                        for (_, peer_mtx) in peer_state_lock.iter() {
@@ -6139,9 +6678,25 @@ where
                                                num_unfunded_channels += 1;
                                        }
                                },
+                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedInboundV2(chan) => {
+                                       // Only inbound V2 channels that are not 0conf and that we do not contribute to will be
+                                       // included in the unfunded count.
+                                       if chan.context.minimum_depth().unwrap_or(1) != 0 &&
+                                               chan.dual_funding_context.our_funding_satoshis == 0 {
+                                               num_unfunded_channels += 1;
+                                       }
+                               },
                                ChannelPhase::UnfundedOutboundV1(_) => {
                                        // Outbound channels don't contribute to the unfunded count in the DoS context.
                                        continue;
+                               },
+                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedOutboundV2(_) => {
+                                       // Outbound channels don't contribute to the unfunded count in the DoS context.
+                                       continue;
                                }
                        }
                }
@@ -6151,12 +6706,14 @@ where
        fn internal_open_channel(&self, counterparty_node_id: &PublicKey, msg: &msgs::OpenChannel) -> Result<(), MsgHandleErrInternal> {
                // Note that the ChannelManager is NOT re-persisted on disk after this, so any changes are
                // likely to be lost on restart!
-               if msg.chain_hash != self.chain_hash {
-                       return Err(MsgHandleErrInternal::send_err_msg_no_close("Unknown genesis block hash".to_owned(), msg.temporary_channel_id.clone()));
+               if msg.common_fields.chain_hash != self.chain_hash {
+                       return Err(MsgHandleErrInternal::send_err_msg_no_close("Unknown genesis block hash".to_owned(),
+                                msg.common_fields.temporary_channel_id.clone()));
                }
 
                if !self.default_configuration.accept_inbound_channels {
-                       return Err(MsgHandleErrInternal::send_err_msg_no_close("No inbound channels accepted".to_owned(), msg.temporary_channel_id.clone()));
+                       return Err(MsgHandleErrInternal::send_err_msg_no_close("No inbound channels accepted".to_owned(),
+                                msg.common_fields.temporary_channel_id.clone()));
                }
 
                // Get the number of peers with channels, but without funded ones. We don't care too much
@@ -6169,7 +6726,9 @@ where
                let peer_state_mutex = per_peer_state.get(counterparty_node_id)
                    .ok_or_else(|| {
                                debug_assert!(false);
-                               MsgHandleErrInternal::send_err_msg_no_close(format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id), msg.temporary_channel_id.clone())
+                               MsgHandleErrInternal::send_err_msg_no_close(
+                                       format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id),
+                                       msg.common_fields.temporary_channel_id.clone())
                        })?;
                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                let peer_state = &mut *peer_state_lock;
@@ -6183,34 +6742,36 @@ where
                {
                        return Err(MsgHandleErrInternal::send_err_msg_no_close(
                                "Have too many peers with unfunded channels, not accepting new ones".to_owned(),
-                               msg.temporary_channel_id.clone()));
+                               msg.common_fields.temporary_channel_id.clone()));
                }
 
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                if Self::unfunded_channel_count(peer_state, best_block_height) >= MAX_UNFUNDED_CHANS_PER_PEER {
                        return Err(MsgHandleErrInternal::send_err_msg_no_close(
                                format!("Refusing more than {} unfunded channels.", MAX_UNFUNDED_CHANS_PER_PEER),
-                               msg.temporary_channel_id.clone()));
+                               msg.common_fields.temporary_channel_id.clone()));
                }
 
-               let channel_id = msg.temporary_channel_id;
+               let channel_id = msg.common_fields.temporary_channel_id;
                let channel_exists = peer_state.has_channel(&channel_id);
                if channel_exists {
-                       return Err(MsgHandleErrInternal::send_err_msg_no_close("temporary_channel_id collision for the same peer!".to_owned(), msg.temporary_channel_id.clone()));
+                       return Err(MsgHandleErrInternal::send_err_msg_no_close(
+                               "temporary_channel_id collision for the same peer!".to_owned(),
+                               msg.common_fields.temporary_channel_id.clone()));
                }
 
                // If we're doing manual acceptance checks on the channel, then defer creation until we're sure we want to accept.
                if self.default_configuration.manually_accept_inbound_channels {
                        let channel_type = channel::channel_type_from_open_channel(
-                                       &msg, &peer_state.latest_features, &self.channel_type_features()
+                                       &msg.common_fields, &peer_state.latest_features, &self.channel_type_features()
                                ).map_err(|e|
-                                       MsgHandleErrInternal::from_chan_no_close(e, msg.temporary_channel_id)
+                                       MsgHandleErrInternal::from_chan_no_close(e, msg.common_fields.temporary_channel_id)
                                )?;
                        let mut pending_events = self.pending_events.lock().unwrap();
                        pending_events.push_back((events::Event::OpenChannelRequest {
-                               temporary_channel_id: msg.temporary_channel_id.clone(),
+                               temporary_channel_id: msg.common_fields.temporary_channel_id.clone(),
                                counterparty_node_id: counterparty_node_id.clone(),
-                               funding_satoshis: msg.funding_satoshis,
+                               funding_satoshis: msg.common_fields.funding_satoshis,
                                push_msat: msg.push_msat,
                                channel_type,
                        }, None));
@@ -6230,17 +6791,21 @@ where
                        &self.default_configuration, best_block_height, &self.logger, /*is_0conf=*/false)
                {
                        Err(e) => {
-                               return Err(MsgHandleErrInternal::from_chan_no_close(e, msg.temporary_channel_id));
+                               return Err(MsgHandleErrInternal::from_chan_no_close(e, msg.common_fields.temporary_channel_id));
                        },
                        Ok(res) => res
                };
 
                let channel_type = channel.context.get_channel_type();
                if channel_type.requires_zero_conf() {
-                       return Err(MsgHandleErrInternal::send_err_msg_no_close("No zero confirmation channels accepted".to_owned(), msg.temporary_channel_id.clone()));
+                       return Err(MsgHandleErrInternal::send_err_msg_no_close(
+                               "No zero confirmation channels accepted".to_owned(),
+                               msg.common_fields.temporary_channel_id.clone()));
                }
                if channel_type.requires_anchors_zero_fee_htlc_tx() {
-                       return Err(MsgHandleErrInternal::send_err_msg_no_close("No channels with anchor outputs accepted".to_owned(), msg.temporary_channel_id.clone()));
+                       return Err(MsgHandleErrInternal::send_err_msg_no_close(
+                               "No channels with anchor outputs accepted".to_owned(),
+                               msg.common_fields.temporary_channel_id.clone()));
                }
 
                let outbound_scid_alias = self.create_and_insert_outbound_scid_alias();
@@ -6262,11 +6827,11 @@ where
                        let peer_state_mutex = per_peer_state.get(counterparty_node_id)
                                .ok_or_else(|| {
                                        debug_assert!(false);
-                                       MsgHandleErrInternal::send_err_msg_no_close(format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id), msg.temporary_channel_id)
+                                       MsgHandleErrInternal::send_err_msg_no_close(format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id), msg.common_fields.temporary_channel_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(msg.temporary_channel_id) {
+                       match peer_state.channel_by_id.entry(msg.common_fields.temporary_channel_id) {
                                hash_map::Entry::Occupied(mut phase) => {
                                        match phase.get_mut() {
                                                ChannelPhase::UnfundedOutboundV1(chan) => {
@@ -6274,16 +6839,16 @@ where
                                                        (chan.context.get_value_satoshis(), chan.context.get_funding_redeemscript().to_v0_p2wsh(), chan.context.get_user_id())
                                                },
                                                _ => {
-                                                       return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got an unexpected accept_channel message from peer with counterparty_node_id {}", counterparty_node_id), msg.temporary_channel_id));
+                                                       return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got an unexpected accept_channel message from peer with counterparty_node_id {}", counterparty_node_id), msg.common_fields.temporary_channel_id));
                                                }
                                        }
                                },
-                               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.temporary_channel_id))
+                               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.common_fields.temporary_channel_id))
                        }
                };
                let mut pending_events = self.pending_events.lock().unwrap();
                pending_events.push_back((events::Event::FundingGenerationReady {
-                       temporary_channel_id: msg.temporary_channel_id,
+                       temporary_channel_id: msg.common_fields.temporary_channel_id,
                        counterparty_node_id: *counterparty_node_id,
                        channel_value_satoshis: value,
                        output_script,
@@ -6554,6 +7119,14 @@ where
                                                let mut chan = remove_channel_phase!(self, chan_phase_entry);
                                                finish_shutdown = Some(chan.context_mut().force_shutdown(false, ClosureReason::CounterpartyCoopClosedUnfundedChannel));
                                        },
+                                       // TODO(dual_funding): Combine this match arm with above.
+                                       #[cfg(dual_funding)]
+                                       ChannelPhase::UnfundedInboundV2(_) | ChannelPhase::UnfundedOutboundV2(_) => {
+                                               let context = phase.context_mut();
+                                               log_error!(self.logger, "Immediately closing unfunded channel {} as peer asked to cooperatively shut it down (which is unnecessary)", &msg.channel_id);
+                                               let mut chan = remove_channel_phase!(self, chan_phase_entry);
+                                               finish_shutdown = Some(chan.context_mut().force_shutdown(false, ClosureReason::CounterpartyCoopClosedUnfundedChannel));
+                                       },
                                }
                        } 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))
@@ -6712,7 +7285,8 @@ where
 
        fn internal_update_fulfill_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) -> Result<(), MsgHandleErrInternal> {
                let funding_txo;
-               let (htlc_source, forwarded_htlc_value) = {
+               let next_user_channel_id;
+               let (htlc_source, forwarded_htlc_value, skimmed_fee_msat) = {
                        let per_peer_state = self.per_peer_state.read().unwrap();
                        let peer_state_mutex = per_peer_state.get(counterparty_node_id)
                                .ok_or_else(|| {
@@ -6741,6 +7315,7 @@ where
                                                // outbound HTLC is claimed. This is guaranteed to all complete before we
                                                // process the RAA as messages are processed from single peers serially.
                                                funding_txo = chan.context.get_funding_txo().expect("We won't accept a fulfill until funded");
+                                               next_user_channel_id = chan.context.get_user_id();
                                                res
                                        } else {
                                                return try_chan_phase_entry!(self, Err(ChannelError::Close(
@@ -6750,7 +7325,11 @@ where
                                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))
                        }
                };
-               self.claim_funds_internal(htlc_source, msg.payment_preimage.clone(), Some(forwarded_htlc_value), false, false, Some(*counterparty_node_id), funding_txo);
+               self.claim_funds_internal(htlc_source, msg.payment_preimage.clone(),
+                       Some(forwarded_htlc_value), skimmed_fee_msat, false, false, Some(*counterparty_node_id),
+                       funding_txo, msg.channel_id, Some(next_user_channel_id),
+               );
+
                Ok(())
        }
 
@@ -6838,8 +7417,8 @@ where
        }
 
        #[inline]
-       fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, OutPoint, u128, Vec<(PendingHTLCInfo, u64)>)]) {
-               for &mut (prev_short_channel_id, prev_funding_outpoint, prev_user_channel_id, ref mut pending_forwards) in per_source_pending_forwards {
+       fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)]) {
+               for &mut (prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_user_channel_id, ref mut pending_forwards) in per_source_pending_forwards {
                        let mut push_forward_event = false;
                        let mut new_intercept_events = VecDeque::new();
                        let mut failed_intercept_forwards = Vec::new();
@@ -6858,7 +7437,7 @@ where
                                        match forward_htlcs.entry(scid) {
                                                hash_map::Entry::Occupied(mut entry) => {
                                                        entry.get_mut().push(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
-                                                               prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info }));
+                                                               prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_htlc_id, prev_user_channel_id, forward_info }));
                                                },
                                                hash_map::Entry::Vacant(entry) => {
                                                        if !is_our_scid && forward_info.incoming_amt_msat.is_some() &&
@@ -6876,15 +7455,16 @@ where
                                                                                        intercept_id
                                                                                }, None));
                                                                                entry.insert(PendingAddHTLCInfo {
-                                                                                       prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info });
+                                                                                       prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_htlc_id, prev_user_channel_id, forward_info });
                                                                        },
                                                                        hash_map::Entry::Occupied(_) => {
-                                                                               let logger = WithContext::from(&self.logger, None, Some(prev_funding_outpoint.to_channel_id()));
+                                                                               let logger = WithContext::from(&self.logger, None, Some(prev_channel_id));
                                                                                log_info!(logger, "Failed to forward incoming HTLC: detected duplicate intercepted payment over short channel id {}", scid);
                                                                                let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                        short_channel_id: prev_short_channel_id,
                                                                                        user_channel_id: Some(prev_user_channel_id),
                                                                                        outpoint: prev_funding_outpoint,
+                                                                                       channel_id: prev_channel_id,
                                                                                        htlc_id: prev_htlc_id,
                                                                                        incoming_packet_shared_secret: forward_info.incoming_shared_secret,
                                                                                        phantom_shared_secret: None,
@@ -6904,7 +7484,7 @@ where
                                                                        push_forward_event = true;
                                                                }
                                                                entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
-                                                                       prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info })));
+                                                                       prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_htlc_id, prev_user_channel_id, forward_info })));
                                                        }
                                                }
                                        }
@@ -6948,13 +7528,14 @@ where
        /// the [`ChannelMonitorUpdate`] in question.
        fn raa_monitor_updates_held(&self,
                actions_blocking_raa_monitor_updates: &BTreeMap<ChannelId, Vec<RAAMonitorUpdateBlockingAction>>,
-               channel_funding_outpoint: OutPoint, counterparty_node_id: PublicKey
+               channel_funding_outpoint: OutPoint, channel_id: ChannelId, counterparty_node_id: PublicKey
        ) -> bool {
                actions_blocking_raa_monitor_updates
-                       .get(&channel_funding_outpoint.to_channel_id()).map(|v| !v.is_empty()).unwrap_or(false)
+                       .get(&channel_id).map(|v| !v.is_empty()).unwrap_or(false)
                || self.pending_events.lock().unwrap().iter().any(|(_, action)| {
                        action == &Some(EventCompletionAction::ReleaseRAAChannelMonitorUpdate {
                                channel_funding_outpoint,
+                               channel_id,
                                counterparty_node_id,
                        })
                })
@@ -6971,7 +7552,7 @@ where
 
                        if let Some(chan) = peer_state.channel_by_id.get(&channel_id) {
                                return self.raa_monitor_updates_held(&peer_state.actions_blocking_raa_monitor_updates,
-                                       chan.context().get_funding_txo().unwrap(), counterparty_node_id);
+                                       chan.context().get_funding_txo().unwrap(), channel_id, counterparty_node_id);
                        }
                }
                false
@@ -6993,7 +7574,7 @@ where
                                                let funding_txo_opt = chan.context.get_funding_txo();
                                                let mon_update_blocked = if let Some(funding_txo) = funding_txo_opt {
                                                        self.raa_monitor_updates_held(
-                                                               &peer_state.actions_blocking_raa_monitor_updates, funding_txo,
+                                                               &peer_state.actions_blocking_raa_monitor_updates, funding_txo, msg.channel_id,
                                                                *counterparty_node_id)
                                                } else { false };
                                                let (htlcs_to_fail, monitor_update_opt) = try_chan_phase_entry!(self,
@@ -7059,7 +7640,7 @@ where
 
                                        peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
                                                msg: try_chan_phase_entry!(self, chan.announcement_signatures(
-                                                       &self.node_signer, self.chain_hash, self.best_block.read().unwrap().height(),
+                                                       &self.node_signer, self.chain_hash, self.best_block.read().unwrap().height,
                                                        msg, &self.default_configuration
                                                ), chan_phase_entry),
                                                // Note that announcement_signatures fails if the channel cannot be announced,
@@ -7239,22 +7820,24 @@ where
                let mut failed_channels = Vec::new();
                let mut pending_monitor_events = self.chain_monitor.release_pending_monitor_events();
                let has_pending_monitor_events = !pending_monitor_events.is_empty();
-               for (funding_outpoint, mut monitor_events, counterparty_node_id) in pending_monitor_events.drain(..) {
+               for (funding_outpoint, channel_id, mut monitor_events, counterparty_node_id) in pending_monitor_events.drain(..) {
                        for monitor_event in monitor_events.drain(..) {
                                match monitor_event {
                                        MonitorEvent::HTLCEvent(htlc_update) => {
-                                               let logger = WithContext::from(&self.logger, counterparty_node_id, Some(funding_outpoint.to_channel_id()));
+                                               let logger = WithContext::from(&self.logger, counterparty_node_id, Some(channel_id));
                                                if let Some(preimage) = htlc_update.payment_preimage {
                                                        log_trace!(logger, "Claiming HTLC with preimage {} from our monitor", preimage);
-                                                       self.claim_funds_internal(htlc_update.source, preimage, htlc_update.htlc_value_satoshis.map(|v| v * 1000), true, false, counterparty_node_id, funding_outpoint);
+                                                       self.claim_funds_internal(htlc_update.source, preimage,
+                                                               htlc_update.htlc_value_satoshis.map(|v| v * 1000), None, true,
+                                                               false, counterparty_node_id, funding_outpoint, channel_id, None);
                                                } else {
                                                        log_trace!(logger, "Failing HTLC with hash {} from our monitor", &htlc_update.payment_hash);
-                                                       let receiver = HTLCDestination::NextHopChannel { node_id: counterparty_node_id, channel_id: funding_outpoint.to_channel_id() };
+                                                       let receiver = HTLCDestination::NextHopChannel { node_id: counterparty_node_id, channel_id };
                                                        let reason = HTLCFailReason::from_failure_code(0x4000 | 8);
                                                        self.fail_htlc_backwards_internal(&htlc_update.source, &htlc_update.payment_hash, &reason, receiver);
                                                }
                                        },
-                                       MonitorEvent::HolderForceClosed(funding_outpoint) => {
+                                       MonitorEvent::HolderForceClosed(_) | MonitorEvent::HolderForceClosedWithInfo { .. } => {
                                                let counterparty_node_id_opt = match counterparty_node_id {
                                                        Some(cp_id) => Some(cp_id),
                                                        None => {
@@ -7270,9 +7853,14 @@ where
                                                                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;
-                                                               if let hash_map::Entry::Occupied(chan_phase_entry) = peer_state.channel_by_id.entry(funding_outpoint.to_channel_id()) {
+                                                               if let hash_map::Entry::Occupied(chan_phase_entry) = peer_state.channel_by_id.entry(channel_id) {
                                                                        if let ChannelPhase::Funded(mut chan) = remove_channel_phase!(self, chan_phase_entry) {
-                                                                               failed_channels.push(chan.context.force_shutdown(false, ClosureReason::HolderForceClosed));
+                                                                               let reason = if let MonitorEvent::HolderForceClosedWithInfo { reason, .. } = monitor_event {
+                                                                                       reason
+                                                                               } else {
+                                                                                       ClosureReason::HolderForceClosed
+                                                                               };
+                                                                               failed_channels.push(chan.context.force_shutdown(false, reason.clone()));
                                                                                if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                                                                        pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                                                                msg: update
@@ -7281,7 +7869,7 @@ where
                                                                                pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                                                        node_id: chan.context.get_counterparty_node_id(),
                                                                                        action: msgs::ErrorAction::DisconnectPeer {
-                                                                                               msg: Some(msgs::ErrorMessage { channel_id: chan.context.channel_id(), data: "Channel force-closed".to_owned() })
+                                                                                               msg: Some(msgs::ErrorMessage { channel_id: chan.context.channel_id(), data: reason.to_string() })
                                                                                        },
                                                                                });
                                                                        }
@@ -7289,8 +7877,8 @@ where
                                                        }
                                                }
                                        },
-                                       MonitorEvent::Completed { funding_txo, monitor_update_id } => {
-                                               self.channel_monitor_updated(&funding_txo, monitor_update_id, counterparty_node_id.as_ref());
+                                       MonitorEvent::Completed { funding_txo, channel_id, monitor_update_id } => {
+                                               self.channel_monitor_updated(&funding_txo, &channel_id, monitor_update_id, counterparty_node_id.as_ref());
                                        },
                                }
                        }
@@ -7507,20 +8095,22 @@ where
                        // Channel::force_shutdown tries to make us do) as we may still be in initialization,
                        // so we track the update internally and handle it when the user next calls
                        // timer_tick_occurred, guaranteeing we're running normally.
-                       if let Some((counterparty_node_id, funding_txo, update)) = failure.monitor_update.take() {
+                       if let Some((counterparty_node_id, funding_txo, channel_id, update)) = failure.monitor_update.take() {
                                assert_eq!(update.updates.len(), 1);
                                if let ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } = update.updates[0] {
                                        assert!(should_broadcast);
                                } else { unreachable!(); }
                                self.pending_background_events.lock().unwrap().push(
                                        BackgroundEvent::MonitorUpdateRegeneratedOnStartup {
-                                               counterparty_node_id, funding_txo, update
+                                               counterparty_node_id, funding_txo, update, channel_id,
                                        });
                        }
                        self.finish_close_channel(failure);
                }
        }
+}
 
+macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
        /// Creates an [`OfferBuilder`] such that the [`Offer`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`InvoiceRequest`] messages for the offer. The offer will
        /// not have an expiration unless otherwise set on the builder.
@@ -7549,23 +8139,25 @@ where
        /// [`Offer`]: crate::offers::offer::Offer
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        pub fn create_offer_builder(
-               &self, description: String
-       ) -> Result<OfferBuilder<DerivedMetadata, secp256k1::All>, Bolt12SemanticError> {
-               let node_id = self.get_our_node_id();
-               let expanded_key = &self.inbound_payment_key;
-               let entropy = &*self.entropy_source;
-               let secp_ctx = &self.secp_ctx;
-
-               let path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
+               &$self, description: String
+       ) -> Result<$builder, Bolt12SemanticError> {
+               let node_id = $self.get_our_node_id();
+               let expanded_key = &$self.inbound_payment_key;
+               let entropy = &*$self.entropy_source;
+               let secp_ctx = &$self.secp_ctx;
+
+               let path = $self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
                let builder = OfferBuilder::deriving_signing_pubkey(
                        description, node_id, expanded_key, entropy, secp_ctx
                )
-                       .chain_hash(self.chain_hash)
+                       .chain_hash($self.chain_hash)
                        .path(path);
 
-               Ok(builder)
+               Ok(builder.into())
        }
+} }
 
+macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
        /// Creates a [`RefundBuilder`] such that the [`Refund`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`Bolt12Invoice`] messages for the refund.
        ///
@@ -7615,31 +8207,55 @@ where
        /// [`Bolt12Invoice::payment_paths`]: crate::offers::invoice::Bolt12Invoice::payment_paths
        /// [Avoiding Duplicate Payments]: #avoiding-duplicate-payments
        pub fn create_refund_builder(
-               &self, description: String, amount_msats: u64, absolute_expiry: Duration,
+               &$self, description: String, amount_msats: u64, absolute_expiry: Duration,
                payment_id: PaymentId, retry_strategy: Retry, max_total_routing_fee_msat: Option<u64>
-       ) -> Result<RefundBuilder<secp256k1::All>, Bolt12SemanticError> {
-               let node_id = self.get_our_node_id();
-               let expanded_key = &self.inbound_payment_key;
-               let entropy = &*self.entropy_source;
-               let secp_ctx = &self.secp_ctx;
+       ) -> Result<$builder, Bolt12SemanticError> {
+               let node_id = $self.get_our_node_id();
+               let expanded_key = &$self.inbound_payment_key;
+               let entropy = &*$self.entropy_source;
+               let secp_ctx = &$self.secp_ctx;
 
-               let path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
+               let path = $self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
                let builder = RefundBuilder::deriving_payer_id(
                        description, node_id, expanded_key, entropy, secp_ctx, amount_msats, payment_id
                )?
-                       .chain_hash(self.chain_hash)
+                       .chain_hash($self.chain_hash)
                        .absolute_expiry(absolute_expiry)
                        .path(path);
 
+               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop($self);
+
                let expiration = StaleExpiration::AbsoluteTimeout(absolute_expiry);
-               self.pending_outbound_payments
+               $self.pending_outbound_payments
                        .add_new_awaiting_invoice(
                                payment_id, expiration, retry_strategy, max_total_routing_fee_msat,
                        )
                        .map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
 
-               Ok(builder)
+               Ok(builder.into())
        }
+} }
+
+impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> ChannelManager<M, T, ES, NS, SP, F, R, L>
+where
+       M::Target: chain::Watch<<SP::Target as SignerProvider>::EcdsaSigner>,
+       T::Target: BroadcasterInterface,
+       ES::Target: EntropySource,
+       NS::Target: NodeSigner,
+       SP::Target: SignerProvider,
+       F::Target: FeeEstimator,
+       R::Target: Router,
+       L::Target: Logger,
+{
+       #[cfg(not(c_bindings))]
+       create_offer_builder!(self, OfferBuilder<DerivedMetadata, secp256k1::All>);
+       #[cfg(not(c_bindings))]
+       create_refund_builder!(self, RefundBuilder<secp256k1::All>);
+
+       #[cfg(c_bindings)]
+       create_offer_builder!(self, OfferWithDerivedMetadataBuilder);
+       #[cfg(c_bindings)]
+       create_refund_builder!(self, RefundMaybeWithDerivedMetadataBuilder);
 
        /// Pays for an [`Offer`] using the given parameters by creating an [`InvoiceRequest`] and
        /// enqueuing it to be sent via an onion message. [`ChannelManager`] will pay the actual
@@ -7684,6 +8300,7 @@ where
        /// Errors if:
        /// - a duplicate `payment_id` is provided given the caveats in the aforementioned link,
        /// - the provided parameters are invalid for the offer,
+       /// - the offer is for an unsupported chain, or
        /// - the parameterized [`Router`] is unable to create a blinded reply path for the invoice
        ///   request.
        ///
@@ -7703,9 +8320,11 @@ where
                let entropy = &*self.entropy_source;
                let secp_ctx = &self.secp_ctx;
 
-               let builder = offer
+               let builder: InvoiceRequestBuilder<DerivedPayerId, secp256k1::All> = offer
                        .request_invoice_deriving_payer_id(expanded_key, entropy, secp_ctx, payment_id)?
-                       .chain_hash(self.chain_hash)?;
+                       .into();
+               let builder = builder.chain_hash(self.chain_hash)?;
+
                let builder = match quantity {
                        None => builder,
                        Some(quantity) => builder.quantity(quantity)?,
@@ -7721,6 +8340,8 @@ where
                let invoice_request = builder.build_and_sign()?;
                let reply_path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
 
+               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+
                let expiration = StaleExpiration::TimerTicks(1);
                self.pending_outbound_payments
                        .add_new_awaiting_invoice(
@@ -7770,8 +8391,10 @@ where
        ///
        /// # Errors
        ///
-       /// Errors if the parameterized [`Router`] is unable to create a blinded payment path or reply
-       /// path for the invoice.
+       /// Errors if:
+       /// - the refund is for an unsupported chain, or
+       /// - the parameterized [`Router`] is unable to create a blinded payment path or reply path for
+       ///   the invoice.
        ///
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn request_refund_payment(&self, refund: &Refund) -> Result<(), Bolt12SemanticError> {
@@ -7782,6 +8405,12 @@ where
                let amount_msats = refund.amount_msats();
                let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32;
 
+               if refund.chain() != self.chain_hash {
+                       return Err(Bolt12SemanticError::UnsupportedChain);
+               }
+
+               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+
                match self.create_inbound_payment(Some(amount_msats), relative_expiry, None) {
                        Ok((payment_hash, payment_secret)) => {
                                let payment_paths = self.create_blinded_payment_paths(amount_msats, payment_secret)
@@ -7799,6 +8428,7 @@ where
                                let builder = refund.respond_using_derived_keys_no_std(
                                        payment_paths, payment_hash, created_at, expanded_key, entropy
                                )?;
+                               let builder: InvoiceBuilder<DerivedSigningPubkey> = builder.into();
                                let invoice = builder.allow_mpp().build_and_sign(secp_ctx)?;
                                let reply_path = self.create_blinded_path()
                                        .map_err(|_| Bolt12SemanticError::MissingPaths)?;
@@ -7933,7 +8563,6 @@ where
        /// Errors if the `MessageRouter` errors or returns an empty `Vec`.
        fn create_blinded_path(&self) -> Result<BlindedPath, ()> {
                let recipient = self.get_our_node_id();
-               let entropy_source = self.entropy_source.deref();
                let secp_ctx = &self.secp_ctx;
 
                let peers = self.per_peer_state.read().unwrap()
@@ -7943,7 +8572,7 @@ where
                        .collect::<Vec<_>>();
 
                self.router
-                       .create_blinded_paths(recipient, peers, entropy_source, secp_ctx)
+                       .create_blinded_paths(recipient, peers, secp_ctx)
                        .and_then(|paths| paths.into_iter().next().ok_or(()))
        }
 
@@ -7952,12 +8581,11 @@ where
        fn create_blinded_payment_paths(
                &self, amount_msats: u64, payment_secret: PaymentSecret
        ) -> Result<Vec<(BlindedPayInfo, BlindedPath)>, ()> {
-               let entropy_source = self.entropy_source.deref();
                let secp_ctx = &self.secp_ctx;
 
                let first_hops = self.list_usable_channels();
                let payee_node_id = self.get_our_node_id();
-               let max_cltv_expiry = self.best_block.read().unwrap().height() + CLTV_FAR_FAR_AWAY
+               let max_cltv_expiry = self.best_block.read().unwrap().height + CLTV_FAR_FAR_AWAY
                        + LATENCY_GRACE_PERIOD_BLOCKS;
                let payee_tlvs = ReceiveTlvs {
                        payment_secret,
@@ -7967,7 +8595,7 @@ where
                        },
                };
                self.router.create_blinded_payment_paths(
-                       payee_node_id, first_hops, payee_tlvs, amount_msats, entropy_source, secp_ctx
+                       payee_node_id, first_hops, payee_tlvs, amount_msats, secp_ctx
                )
        }
 
@@ -7976,7 +8604,7 @@ where
        ///
        /// [phantom node payments]: crate::sign::PhantomKeysManager
        pub fn get_phantom_scid(&self) -> u64 {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let short_to_chan_info = self.short_to_chan_info.read().unwrap();
                loop {
                        let scid_candidate = fake_scid::Namespace::Phantom.get_fake_scid(best_block_height, &self.chain_hash, &self.fake_scid_rand_bytes, &self.entropy_source);
@@ -8006,7 +8634,7 @@ where
        /// Note that this method is not guaranteed to return unique values, you may need to call it a few
        /// times to get a unique scid.
        pub fn get_intercept_scid(&self) -> u64 {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let short_to_chan_info = self.short_to_chan_info.read().unwrap();
                loop {
                        let scid_candidate = fake_scid::Namespace::Intercept.get_fake_scid(best_block_height, &self.chain_hash, &self.fake_scid_rand_bytes, &self.entropy_source);
@@ -8073,9 +8701,12 @@ where
        /// [`Event`] being handled) completes, this should be called to restore the channel to normal
        /// operation. It will double-check that nothing *else* is also blocking the same channel from
        /// making progress and then let any blocked [`ChannelMonitorUpdate`]s fly.
-       fn handle_monitor_update_release(&self, counterparty_node_id: PublicKey, channel_funding_outpoint: OutPoint, mut completed_blocker: Option<RAAMonitorUpdateBlockingAction>) {
+       fn handle_monitor_update_release(&self, counterparty_node_id: PublicKey,
+               channel_funding_outpoint: OutPoint, channel_id: ChannelId,
+               mut completed_blocker: Option<RAAMonitorUpdateBlockingAction>) {
+
                let logger = WithContext::from(
-                       &self.logger, Some(counterparty_node_id), Some(channel_funding_outpoint.to_channel_id())
+                       &self.logger, Some(counterparty_node_id), Some(channel_id),
                );
                loop {
                        let per_peer_state = self.per_peer_state.read().unwrap();
@@ -8085,28 +8716,29 @@ where
                                if let Some(blocker) = completed_blocker.take() {
                                        // Only do this on the first iteration of the loop.
                                        if let Some(blockers) = peer_state.actions_blocking_raa_monitor_updates
-                                               .get_mut(&channel_funding_outpoint.to_channel_id())
+                                               .get_mut(&channel_id)
                                        {
                                                blockers.retain(|iter| iter != &blocker);
                                        }
                                }
 
                                if self.raa_monitor_updates_held(&peer_state.actions_blocking_raa_monitor_updates,
-                                       channel_funding_outpoint, counterparty_node_id) {
+                                       channel_funding_outpoint, channel_id, counterparty_node_id) {
                                        // Check that, while holding the peer lock, we don't have anything else
                                        // blocking monitor updates for this channel. If we do, release the monitor
                                        // update(s) when those blockers complete.
                                        log_trace!(logger, "Delaying monitor unlock for channel {} as another channel's mon update needs to complete first",
-                                               &channel_funding_outpoint.to_channel_id());
+                                               &channel_id);
                                        break;
                                }
 
-                               if let hash_map::Entry::Occupied(mut chan_phase_entry) = peer_state.channel_by_id.entry(channel_funding_outpoint.to_channel_id()) {
+                               if let hash_map::Entry::Occupied(mut chan_phase_entry) = peer_state.channel_by_id.entry(
+                                       channel_id) {
                                        if let ChannelPhase::Funded(chan) = chan_phase_entry.get_mut() {
                                                debug_assert_eq!(chan.context.get_funding_txo().unwrap(), channel_funding_outpoint);
                                                if let Some((monitor_update, further_update_exists)) = chan.unblock_next_blocked_monitor_update() {
                                                        log_debug!(logger, "Unlocking monitor updating for channel {} and updating monitor",
-                                                               channel_funding_outpoint.to_channel_id());
+                                                               channel_id);
                                                        handle_new_monitor_update!(self, channel_funding_outpoint, monitor_update,
                                                                peer_state_lck, peer_state, per_peer_state, chan);
                                                        if further_update_exists {
@@ -8116,7 +8748,7 @@ where
                                                        }
                                                } else {
                                                        log_trace!(logger, "Unlocked monitor updating for channel {} without monitors to update",
-                                                               channel_funding_outpoint.to_channel_id());
+                                                               channel_id);
                                                }
                                        }
                                }
@@ -8133,9 +8765,9 @@ where
                for action in actions {
                        match action {
                                EventCompletionAction::ReleaseRAAChannelMonitorUpdate {
-                                       channel_funding_outpoint, counterparty_node_id
+                                       channel_funding_outpoint, channel_id, counterparty_node_id
                                } => {
-                                       self.handle_monitor_update_release(counterparty_node_id, channel_funding_outpoint, None);
+                                       self.handle_monitor_update_release(counterparty_node_id, channel_funding_outpoint, channel_id, None);
                                }
                        }
                }
@@ -8250,9 +8882,9 @@ where
        fn filtered_block_connected(&self, header: &Header, txdata: &TransactionData, height: u32) {
                {
                        let best_block = self.best_block.read().unwrap();
-                       assert_eq!(best_block.block_hash(), header.prev_blockhash,
+                       assert_eq!(best_block.block_hash, header.prev_blockhash,
                                "Blocks must be connected in chain-order - the connected header must build on the last connected header");
-                       assert_eq!(best_block.height(), height - 1,
+                       assert_eq!(best_block.height, height - 1,
                                "Blocks must be connected in chain-order - the connected block height must be one greater than the previous height");
                }
 
@@ -8267,9 +8899,9 @@ where
                let new_height = height - 1;
                {
                        let mut best_block = self.best_block.write().unwrap();
-                       assert_eq!(best_block.block_hash(), header.block_hash(),
+                       assert_eq!(best_block.block_hash, header.block_hash(),
                                "Blocks must be disconnected in chain-order - the disconnected header must be the last connected header");
-                       assert_eq!(best_block.height(), height,
+                       assert_eq!(best_block.height, height,
                                "Blocks must be disconnected in chain-order - the disconnected block must have the correct height");
                        *best_block = BestBlock::new(header.prev_blockhash, new_height)
                }
@@ -8303,7 +8935,7 @@ where
                self.do_chain_event(Some(height), |channel| channel.transactions_confirmed(&block_hash, height, txdata, self.chain_hash, &self.node_signer, &self.default_configuration, &&WithChannelContext::from(&self.logger, &channel.context))
                        .map(|(a, b)| (a, Vec::new(), b)));
 
-               let last_best_block_height = self.best_block.read().unwrap().height();
+               let last_best_block_height = self.best_block.read().unwrap().height;
                if height < last_best_block_height {
                        let timestamp = self.highest_seen_timestamp.load(Ordering::Acquire);
                        self.do_chain_event(Some(last_best_block_height), |channel| channel.best_block_updated(last_best_block_height, timestamp as u32, self.chain_hash, &self.node_signer, &self.default_configuration, &&WithChannelContext::from(&self.logger, &channel.context)));
@@ -8411,6 +9043,9 @@ where
                                        match phase {
                                                // Retain unfunded channels.
                                                ChannelPhase::UnfundedOutboundV1(_) | ChannelPhase::UnfundedInboundV1(_) => true,
+                                               // TODO(dual_funding): Combine this match arm with above.
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedOutboundV2(_) | ChannelPhase::UnfundedInboundV2(_) => true,
                                                ChannelPhase::Funded(channel) => {
                                                        let res = f(channel);
                                                        if let Ok((channel_ready_opt, mut timed_out_pending_htlcs, announcement_sigs)) = res {
@@ -8531,6 +9166,7 @@ where
                                                incoming_packet_shared_secret: htlc.forward_info.incoming_shared_secret,
                                                phantom_shared_secret: None,
                                                outpoint: htlc.prev_funding_outpoint,
+                                               channel_id: htlc.prev_channel_id,
                                                blinded_failure: htlc.forward_info.routing.blinded_failure(),
                                        });
 
@@ -8542,7 +9178,7 @@ where
                                                        HTLCFailReason::from_failure_code(0x2000 | 2),
                                                        HTLCDestination::InvalidForward { requested_forward_scid }));
                                        let logger = WithContext::from(
-                                               &self.logger, None, Some(htlc.prev_funding_outpoint.to_channel_id())
+                                               &self.logger, None, Some(htlc.prev_channel_id)
                                        );
                                        log_trace!(logger, "Timing out intercepted HTLC with requested forward scid {}", requested_forward_scid);
                                        false
@@ -8570,6 +9206,9 @@ where
        }
 
        /// Returns true if this [`ChannelManager`] needs to be persisted.
+       ///
+       /// See [`Self::get_event_or_persistence_needed_future`] for retrieving a [`Future`] that
+       /// indicates this should be checked.
        pub fn get_and_clear_needs_persistence(&self) -> bool {
                self.needs_persist_flag.swap(false, Ordering::AcqRel)
        }
@@ -8659,7 +9298,7 @@ where
        fn handle_open_channel_v2(&self, counterparty_node_id: &PublicKey, msg: &msgs::OpenChannelV2) {
                let _: Result<(), _> = handle_error!(self, Err(MsgHandleErrInternal::send_err_msg_no_close(
                        "Dual-funded channels not supported".to_owned(),
-                        msg.temporary_channel_id.clone())), *counterparty_node_id);
+                        msg.common_fields.temporary_channel_id.clone())), *counterparty_node_id);
        }
 
        fn handle_accept_channel(&self, counterparty_node_id: &PublicKey, msg: &msgs::AcceptChannel) {
@@ -8675,7 +9314,7 @@ where
        fn handle_accept_channel_v2(&self, counterparty_node_id: &PublicKey, msg: &msgs::AcceptChannelV2) {
                let _: Result<(), _> = handle_error!(self, Err(MsgHandleErrInternal::send_err_msg_no_close(
                        "Dual-funded channels not supported".to_owned(),
-                        msg.temporary_channel_id.clone())), *counterparty_node_id);
+                        msg.common_fields.temporary_channel_id.clone())), *counterparty_node_id);
        }
 
        fn handle_funding_created(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingCreated) {
@@ -8870,13 +9509,23 @@ where
                                                        }
                                                        &mut chan.context
                                                },
-                                               // Unfunded channels will always be removed.
-                                               ChannelPhase::UnfundedOutboundV1(chan) => {
-                                                       &mut chan.context
+                                               // We retain UnfundedOutboundV1 channel for some time in case
+                                               // peer unexpectedly disconnects, and intends to reconnect again.
+                                               ChannelPhase::UnfundedOutboundV1(_) => {
+                                                       return true;
                                                },
+                                               // Unfunded inbound channels will always be removed.
                                                ChannelPhase::UnfundedInboundV1(chan) => {
                                                        &mut chan.context
                                                },
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedOutboundV2(chan) => {
+                                                       &mut chan.context
+                                               },
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedInboundV2(chan) => {
+                                                       &mut chan.context
+                                               },
                                        };
                                        // Clean up for removal.
                                        update_maps_on_chan_removal!(self, &context);
@@ -8975,8 +9624,8 @@ where
                                                        return NotifyOption::SkipPersistNoEvents;
                                                }
                                                e.insert(Mutex::new(PeerState {
-                                                       channel_by_id: HashMap::new(),
-                                                       inbound_channel_request_by_id: HashMap::new(),
+                                                       channel_by_id: new_hash_map(),
+                                                       inbound_channel_request_by_id: new_hash_map(),
                                                        latest_features: init_msg.features.clone(),
                                                        pending_msg_events: Vec::new(),
                                                        in_flight_monitor_updates: BTreeMap::new(),
@@ -8989,7 +9638,7 @@ where
                                                let mut peer_state = e.get().lock().unwrap();
                                                peer_state.latest_features = init_msg.features.clone();
 
-                                               let best_block_height = self.best_block.read().unwrap().height();
+                                               let best_block_height = self.best_block.read().unwrap().height;
                                                if inbound_peer_limited &&
                                                        Self::unfunded_channel_count(&*peer_state, best_block_height) ==
                                                        peer_state.channel_by_id.len()
@@ -9012,15 +9661,49 @@ where
                                let peer_state = &mut *peer_state_lock;
                                let pending_msg_events = &mut peer_state.pending_msg_events;
 
-                               peer_state.channel_by_id.iter_mut().filter_map(|(_, phase)|
-                                       if let ChannelPhase::Funded(chan) = phase { Some(chan) } else { None }
-                               ).for_each(|chan| {
-                                       let logger = WithChannelContext::from(&self.logger, &chan.context);
-                                       pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
-                                               node_id: chan.context.get_counterparty_node_id(),
-                                               msg: chan.get_channel_reestablish(&&logger),
-                                       });
-                               });
+                               for (_, phase) in peer_state.channel_by_id.iter_mut() {
+                                       match phase {
+                                               ChannelPhase::Funded(chan) => {
+                                                       let logger = WithChannelContext::from(&self.logger, &chan.context);
+                                                       pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
+                                                               node_id: chan.context.get_counterparty_node_id(),
+                                                               msg: chan.get_channel_reestablish(&&logger),
+                                                       });
+                                               }
+
+                                               ChannelPhase::UnfundedOutboundV1(chan) => {
+                                                       pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
+                                                               node_id: chan.context.get_counterparty_node_id(),
+                                                               msg: chan.get_open_channel(self.chain_hash),
+                                                       });
+                                               }
+
+                                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedOutboundV2(chan) => {
+                                                       pending_msg_events.push(events::MessageSendEvent::SendOpenChannelV2 {
+                                                               node_id: chan.context.get_counterparty_node_id(),
+                                                               msg: chan.get_open_channel_v2(self.chain_hash),
+                                                       });
+                                               },
+
+                                               ChannelPhase::UnfundedInboundV1(_) => {
+                                                       // Since unfunded inbound channel maps are cleared upon disconnecting a peer,
+                                                       // they are not persisted and won't be recovered after a crash.
+                                                       // Therefore, they shouldn't exist at this point.
+                                                       debug_assert!(false);
+                                               }
+
+                                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedInboundV2(channel) => {
+                                                       // Since unfunded inbound channel maps are cleared upon disconnecting a peer,
+                                                       // they are not persisted and won't be recovered after a crash.
+                                                       // Therefore, they shouldn't exist at this point.
+                                                       debug_assert!(false);
+                                               },
+                                       }
+                               }
                        }
 
                        return NotifyOption::SkipPersistHandleEvents;
@@ -9030,8 +9713,6 @@ where
        }
 
        fn handle_error(&self, counterparty_node_id: &PublicKey, msg: &msgs::ErrorMessage) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-
                match &msg.data as &str {
                        "cannot co-op close channel w/ active htlcs"|
                        "link failed to shutdown" =>
@@ -9044,34 +9725,45 @@ where
                                // We're not going to bother handling this in a sensible way, instead simply
                                // repeating the Shutdown message on repeat until morale improves.
                                if !msg.channel_id.is_zero() {
-                                       let per_peer_state = self.per_peer_state.read().unwrap();
-                                       let peer_state_mutex_opt = per_peer_state.get(counterparty_node_id);
-                                       if peer_state_mutex_opt.is_none() { return; }
-                                       let mut peer_state = peer_state_mutex_opt.unwrap().lock().unwrap();
-                                       if let Some(ChannelPhase::Funded(chan)) = peer_state.channel_by_id.get(&msg.channel_id) {
-                                               if let Some(msg) = chan.get_outbound_shutdown() {
-                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
-                                                               node_id: *counterparty_node_id,
-                                                               msg,
-                                                       });
-                                               }
-                                               peer_state.pending_msg_events.push(events::MessageSendEvent::HandleError {
-                                                       node_id: *counterparty_node_id,
-                                                       action: msgs::ErrorAction::SendWarningMessage {
-                                                               msg: msgs::WarningMessage {
-                                                                       channel_id: msg.channel_id,
-                                                                       data: "You appear to be exhibiting LND bug 6039, we'll keep sending you shutdown messages until you handle them correctly".to_owned()
-                                                               },
-                                                               log_level: Level::Trace,
+                                       PersistenceNotifierGuard::optionally_notify(
+                                               self,
+                                               || -> NotifyOption {
+                                                       let per_peer_state = self.per_peer_state.read().unwrap();
+                                                       let peer_state_mutex_opt = per_peer_state.get(counterparty_node_id);
+                                                       if peer_state_mutex_opt.is_none() { return NotifyOption::SkipPersistNoEvents; }
+                                                       let mut peer_state = peer_state_mutex_opt.unwrap().lock().unwrap();
+                                                       if let Some(ChannelPhase::Funded(chan)) = peer_state.channel_by_id.get(&msg.channel_id) {
+                                                               if let Some(msg) = chan.get_outbound_shutdown() {
+                                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
+                                                                               node_id: *counterparty_node_id,
+                                                                               msg,
+                                                                       });
+                                                               }
+                                                               peer_state.pending_msg_events.push(events::MessageSendEvent::HandleError {
+                                                                       node_id: *counterparty_node_id,
+                                                                       action: msgs::ErrorAction::SendWarningMessage {
+                                                                               msg: msgs::WarningMessage {
+                                                                                       channel_id: msg.channel_id,
+                                                                                       data: "You appear to be exhibiting LND bug 6039, we'll keep sending you shutdown messages until you handle them correctly".to_owned()
+                                                                               },
+                                                                               log_level: Level::Trace,
+                                                                       }
+                                                               });
+                                                               // This can happen in a fairly tight loop, so we absolutely cannot trigger
+                                                               // a `ChannelManager` write here.
+                                                               return NotifyOption::SkipPersistHandleEvents;
                                                        }
-                                               });
-                                       }
+                                                       NotifyOption::SkipPersistNoEvents
+                                               }
+                                       );
                                }
                                return;
                        }
                        _ => {}
                }
 
+               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+
                if msg.channel_id.is_zero() {
                        let channel_ids: Vec<ChannelId> = {
                                let per_peer_state = self.per_peer_state.read().unwrap();
@@ -9096,14 +9788,29 @@ where
                                if peer_state_mutex_opt.is_none() { return; }
                                let mut peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
                                let peer_state = &mut *peer_state_lock;
-                               if let Some(ChannelPhase::UnfundedOutboundV1(chan)) = peer_state.channel_by_id.get_mut(&msg.channel_id) {
-                                       if let Ok(msg) = chan.maybe_handle_error_without_close(self.chain_hash, &self.fee_estimator) {
-                                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
-                                                       node_id: *counterparty_node_id,
-                                                       msg,
-                                               });
-                                               return;
-                                       }
+                               match peer_state.channel_by_id.get_mut(&msg.channel_id) {
+                                       Some(ChannelPhase::UnfundedOutboundV1(ref mut chan)) => {
+                                               if let Ok(msg) = chan.maybe_handle_error_without_close(self.chain_hash, &self.fee_estimator) {
+                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
+                                                               node_id: *counterparty_node_id,
+                                                               msg,
+                                                       });
+                                                       return;
+                                               }
+                                       },
+                                       #[cfg(dual_funding)]
+                                       Some(ChannelPhase::UnfundedOutboundV2(ref mut chan)) => {
+                                               if let Ok(msg) = chan.maybe_handle_error_without_close(self.chain_hash, &self.fee_estimator) {
+                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannelV2 {
+                                                               node_id: *counterparty_node_id,
+                                                               msg,
+                                                       });
+                                                       return;
+                                               }
+                                       },
+                                       None | Some(ChannelPhase::UnfundedInboundV1(_) | ChannelPhase::Funded(_)) => (),
+                                       #[cfg(dual_funding)]
+                                       Some(ChannelPhase::UnfundedInboundV2(_)) => (),
                                }
                        }
 
@@ -9246,6 +9953,8 @@ where
                                        let builder = invoice_request.respond_using_derived_keys_no_std(
                                                payment_paths, payment_hash, created_at
                                        );
+                                       let builder: Result<InvoiceBuilder<DerivedSigningPubkey>, _> =
+                                               builder.map(|b| b.into());
                                        match builder.and_then(|b| b.allow_mpp().build_and_sign(secp_ctx)) {
                                                Ok(invoice) => Some(OffersMessage::Invoice(invoice)),
                                                Err(error) => Some(OffersMessage::InvoiceError(error.into())),
@@ -9257,18 +9966,25 @@ where
                                        let builder = invoice_request.respond_with_no_std(
                                                payment_paths, payment_hash, created_at
                                        );
+                                       let builder: Result<InvoiceBuilder<ExplicitSigningPubkey>, _> =
+                                               builder.map(|b| b.into());
                                        let response = builder.and_then(|builder| builder.allow_mpp().build())
                                                .map_err(|e| OffersMessage::InvoiceError(e.into()))
-                                               .and_then(|invoice|
-                                                       match invoice.sign(|invoice| self.node_signer.sign_bolt12_invoice(invoice)) {
+                                               .and_then(|invoice| {
+                                                       #[cfg(c_bindings)]
+                                                       let mut invoice = invoice;
+                                                       match invoice.sign(|invoice: &UnsignedBolt12Invoice|
+                                                               self.node_signer.sign_bolt12_invoice(invoice)
+                                                       ) {
                                                                Ok(invoice) => Ok(OffersMessage::Invoice(invoice)),
-                                                               Err(SignError::Signing(())) => Err(OffersMessage::InvoiceError(
+                                                               Err(SignError::Signing) => Err(OffersMessage::InvoiceError(
                                                                                InvoiceError::from_string("Failed signing invoice".to_string())
                                                                )),
                                                                Err(SignError::Verification(_)) => Err(OffersMessage::InvoiceError(
                                                                                InvoiceError::from_string("Failed invoice signature verification".to_string())
                                                                )),
-                                                       });
+                                                       }
+                                               });
                                        match response {
                                                Ok(invoice) => Some(invoice),
                                                Err(error) => Some(error),
@@ -9419,6 +10135,8 @@ impl Writeable for ChannelDetails {
                        (37, user_channel_id_high_opt, option),
                        (39, self.feerate_sat_per_1000_weight, option),
                        (41, self.channel_shutdown_state, option),
+                       (43, self.pending_inbound_htlcs, optional_vec),
+                       (45, self.pending_outbound_htlcs, optional_vec),
                });
                Ok(())
        }
@@ -9457,6 +10175,8 @@ impl Readable for ChannelDetails {
                        (37, user_channel_id_high_opt, option),
                        (39, feerate_sat_per_1000_weight, option),
                        (41, channel_shutdown_state, option),
+                       (43, pending_inbound_htlcs, optional_vec),
+                       (45, pending_outbound_htlcs, optional_vec),
                });
 
                // `user_channel_id` used to be a single u64 value. In order to remain backwards compatible with
@@ -9493,6 +10213,8 @@ impl Readable for ChannelDetails {
                        inbound_htlc_maximum_msat,
                        feerate_sat_per_1000_weight,
                        channel_shutdown_state,
+                       pending_inbound_htlcs: pending_inbound_htlcs.unwrap_or(Vec::new()),
+                       pending_outbound_htlcs: pending_outbound_htlcs.unwrap_or(Vec::new()),
                })
        }
 }
@@ -9524,6 +10246,7 @@ impl_writeable_tlv_based_enum!(PendingHTLCRouting,
        },
        (2, ReceiveKeysend) => {
                (0, payment_preimage, required),
+               (1, requires_blinded_error, (default_value, false)),
                (2, incoming_cltv_expiry, required),
                (3, payment_metadata, option),
                (4, payment_data, option), // Added in 0.0.116
@@ -9627,6 +10350,9 @@ impl_writeable_tlv_based!(HTLCPreviousHopData, {
        (4, htlc_id, required),
        (6, incoming_packet_shared_secret, required),
        (7, user_channel_id, option),
+       // Note that by the time we get past the required read for type 2 above, outpoint will be
+       // filled in, so we can safely unwrap it here.
+       (9, channel_id, (default_value, ChannelId::v1_from_funding_outpoint(outpoint.0.unwrap()))),
 });
 
 impl Writeable for ClaimableHTLC {
@@ -9778,6 +10504,9 @@ impl_writeable_tlv_based!(PendingAddHTLCInfo, {
        (2, prev_short_channel_id, required),
        (4, prev_htlc_id, required),
        (6, prev_funding_outpoint, required),
+       // Note that by the time we get past the required read for type 6 above, prev_funding_outpoint will be
+       // filled in, so we can safely unwrap it here.
+       (7, prev_channel_id, (default_value, ChannelId::v1_from_funding_outpoint(prev_funding_outpoint.0.unwrap()))),
 });
 
 impl Writeable for HTLCForwardInfo {
@@ -9870,8 +10599,8 @@ where
                self.chain_hash.write(writer)?;
                {
                        let best_block = self.best_block.read().unwrap();
-                       best_block.height().write(writer)?;
-                       best_block.block_hash().write(writer)?;
+                       best_block.height.write(writer)?;
+                       best_block.block_hash.write(writer)?;
                }
 
                let mut serializable_peer_count: u64 = 0;
@@ -10021,7 +10750,7 @@ where
                }
 
                // Encode without retry info for 0.0.101 compatibility.
-               let mut pending_outbound_payments_no_retry: HashMap<PaymentId, HashSet<[u8; 32]>> = HashMap::new();
+               let mut pending_outbound_payments_no_retry: HashMap<PaymentId, HashSet<[u8; 32]>> = new_hash_map();
                for (id, outbound) in pending_outbound_payments.iter() {
                        match outbound {
                                PendingOutboundPayment::Legacy { session_privs } |
@@ -10049,7 +10778,7 @@ where
                for ((counterparty_id, _), peer_state) in per_peer_state.iter().zip(peer_states.iter()) {
                        for (funding_outpoint, updates) in peer_state.in_flight_monitor_updates.iter() {
                                if !updates.is_empty() {
-                                       if in_flight_monitor_updates.is_none() { in_flight_monitor_updates = Some(HashMap::new()); }
+                                       if in_flight_monitor_updates.is_none() { in_flight_monitor_updates = Some(new_hash_map()); }
                                        in_flight_monitor_updates.as_mut().unwrap().insert((counterparty_id, funding_outpoint), updates);
                                }
                        }
@@ -10238,7 +10967,9 @@ where
                        mut channel_monitors: Vec<&'a mut ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>>) -> Self {
                Self {
                        entropy_source, node_signer, signer_provider, fee_estimator, chain_monitor, tx_broadcaster, router, logger, default_config,
-                       channel_monitors: channel_monitors.drain(..).map(|monitor| { (monitor.get_funding_txo().0, monitor) }).collect()
+                       channel_monitors: hash_map_from_iter(
+                               channel_monitors.drain(..).map(|monitor| { (monitor.get_funding_txo().0, monitor) })
+                       ),
                }
        }
 }
@@ -10285,18 +11016,20 @@ where
                let mut failed_htlcs = Vec::new();
 
                let channel_count: u64 = Readable::read(reader)?;
-               let mut funding_txo_set = HashSet::with_capacity(cmp::min(channel_count as usize, 128));
-               let mut funded_peer_channels: HashMap<PublicKey, HashMap<ChannelId, ChannelPhase<SP>>> = HashMap::with_capacity(cmp::min(channel_count as usize, 128));
-               let mut outpoint_to_peer = HashMap::with_capacity(cmp::min(channel_count as usize, 128));
-               let mut short_to_chan_info = HashMap::with_capacity(cmp::min(channel_count as usize, 128));
+               let mut funding_txo_set = hash_set_with_capacity(cmp::min(channel_count as usize, 128));
+               let mut funded_peer_channels: HashMap<PublicKey, HashMap<ChannelId, ChannelPhase<SP>>> = hash_map_with_capacity(cmp::min(channel_count as usize, 128));
+               let mut outpoint_to_peer = hash_map_with_capacity(cmp::min(channel_count as usize, 128));
+               let mut short_to_chan_info = hash_map_with_capacity(cmp::min(channel_count as usize, 128));
                let mut channel_closures = VecDeque::new();
                let mut close_background_events = Vec::new();
+               let mut funding_txo_to_channel_id = hash_map_with_capacity(channel_count as usize);
                for _ in 0..channel_count {
                        let mut channel: Channel<SP> = Channel::read(reader, (
                                &args.entropy_source, &args.signer_provider, best_block_height, &provided_channel_type_features(&args.default_config)
                        ))?;
                        let logger = WithChannelContext::from(&args.logger, &channel.context);
                        let funding_txo = channel.context.get_funding_txo().ok_or(DecodeError::InvalidValue)?;
+                       funding_txo_to_channel_id.insert(funding_txo, channel.context.channel_id());
                        funding_txo_set.insert(funding_txo.clone());
                        if let Some(ref mut monitor) = args.channel_monitors.get_mut(&funding_txo) {
                                if channel.get_cur_holder_commitment_transaction_number() > monitor.get_cur_holder_commitment_number() ||
@@ -10326,9 +11059,9 @@ where
                                        if shutdown_result.unbroadcasted_batch_funding_txid.is_some() {
                                                return Err(DecodeError::InvalidValue);
                                        }
-                                       if let Some((counterparty_node_id, funding_txo, update)) = shutdown_result.monitor_update {
+                                       if let Some((counterparty_node_id, funding_txo, channel_id, update)) = shutdown_result.monitor_update {
                                                close_background_events.push(BackgroundEvent::MonitorUpdateRegeneratedOnStartup {
-                                                       counterparty_node_id, funding_txo, update
+                                                       counterparty_node_id, funding_txo, channel_id, update
                                                });
                                        }
                                        failed_htlcs.append(&mut shutdown_result.dropped_outbound_htlcs);
@@ -10375,7 +11108,7 @@ where
                                                        by_id_map.insert(channel.context.channel_id(), ChannelPhase::Funded(channel));
                                                },
                                                hash_map::Entry::Vacant(entry) => {
-                                                       let mut by_id_map = HashMap::new();
+                                                       let mut by_id_map = new_hash_map();
                                                        by_id_map.insert(channel.context.channel_id(), ChannelPhase::Funded(channel));
                                                        entry.insert(by_id_map);
                                                }
@@ -10407,20 +11140,22 @@ where
                for (funding_txo, monitor) in args.channel_monitors.iter() {
                        if !funding_txo_set.contains(funding_txo) {
                                let logger = WithChannelMonitor::from(&args.logger, monitor);
+                               let channel_id = monitor.channel_id();
                                log_info!(logger, "Queueing monitor update to ensure missing channel {} is force closed",
-                                       &funding_txo.to_channel_id());
+                                       &channel_id);
                                let monitor_update = ChannelMonitorUpdate {
                                        update_id: CLOSED_CHANNEL_UPDATE_ID,
                                        counterparty_node_id: None,
                                        updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast: true }],
+                                       channel_id: Some(monitor.channel_id()),
                                };
-                               close_background_events.push(BackgroundEvent::ClosedMonitorUpdateRegeneratedOnStartup((*funding_txo, monitor_update)));
+                               close_background_events.push(BackgroundEvent::ClosedMonitorUpdateRegeneratedOnStartup((*funding_txo, channel_id, monitor_update)));
                        }
                }
 
                const MAX_ALLOC_SIZE: usize = 1024 * 64;
                let forward_htlcs_count: u64 = Readable::read(reader)?;
-               let mut forward_htlcs = HashMap::with_capacity(cmp::min(forward_htlcs_count as usize, 128));
+               let mut forward_htlcs = hash_map_with_capacity(cmp::min(forward_htlcs_count as usize, 128));
                for _ in 0..forward_htlcs_count {
                        let short_channel_id = Readable::read(reader)?;
                        let pending_forwards_count: u64 = Readable::read(reader)?;
@@ -10446,7 +11181,7 @@ where
                let peer_state_from_chans = |channel_by_id| {
                        PeerState {
                                channel_by_id,
-                               inbound_channel_request_by_id: HashMap::new(),
+                               inbound_channel_request_by_id: new_hash_map(),
                                latest_features: InitFeatures::empty(),
                                pending_msg_events: Vec::new(),
                                in_flight_monitor_updates: BTreeMap::new(),
@@ -10457,10 +11192,10 @@ where
                };
 
                let peer_count: u64 = Readable::read(reader)?;
-               let mut per_peer_state = HashMap::with_capacity(cmp::min(peer_count as usize, MAX_ALLOC_SIZE/mem::size_of::<(PublicKey, Mutex<PeerState<SP>>)>()));
+               let mut per_peer_state = hash_map_with_capacity(cmp::min(peer_count as usize, MAX_ALLOC_SIZE/mem::size_of::<(PublicKey, Mutex<PeerState<SP>>)>()));
                for _ in 0..peer_count {
                        let peer_pubkey = Readable::read(reader)?;
-                       let peer_chans = funded_peer_channels.remove(&peer_pubkey).unwrap_or(HashMap::new());
+                       let peer_chans = funded_peer_channels.remove(&peer_pubkey).unwrap_or(new_hash_map());
                        let mut peer_state = peer_state_from_chans(peer_chans);
                        peer_state.latest_features = Readable::read(reader)?;
                        per_peer_state.insert(peer_pubkey, Mutex::new(peer_state));
@@ -10494,7 +11229,7 @@ where
                let highest_seen_timestamp: u32 = Readable::read(reader)?;
 
                let pending_inbound_payment_count: u64 = Readable::read(reader)?;
-               let mut pending_inbound_payments: HashMap<PaymentHash, PendingInboundPayment> = HashMap::with_capacity(cmp::min(pending_inbound_payment_count as usize, MAX_ALLOC_SIZE/(3*32)));
+               let mut pending_inbound_payments: HashMap<PaymentHash, PendingInboundPayment> = hash_map_with_capacity(cmp::min(pending_inbound_payment_count as usize, MAX_ALLOC_SIZE/(3*32)));
                for _ in 0..pending_inbound_payment_count {
                        if pending_inbound_payments.insert(Readable::read(reader)?, Readable::read(reader)?).is_some() {
                                return Err(DecodeError::InvalidValue);
@@ -10503,11 +11238,11 @@ where
 
                let pending_outbound_payments_count_compat: u64 = Readable::read(reader)?;
                let mut pending_outbound_payments_compat: HashMap<PaymentId, PendingOutboundPayment> =
-                       HashMap::with_capacity(cmp::min(pending_outbound_payments_count_compat as usize, MAX_ALLOC_SIZE/32));
+                       hash_map_with_capacity(cmp::min(pending_outbound_payments_count_compat as usize, MAX_ALLOC_SIZE/32));
                for _ in 0..pending_outbound_payments_count_compat {
                        let session_priv = Readable::read(reader)?;
                        let payment = PendingOutboundPayment::Legacy {
-                               session_privs: [session_priv].iter().cloned().collect()
+                               session_privs: hash_set_from_iter([session_priv]),
                        };
                        if pending_outbound_payments_compat.insert(PaymentId(session_priv), payment).is_some() {
                                return Err(DecodeError::InvalidValue)
@@ -10517,13 +11252,13 @@ where
                // pending_outbound_payments_no_retry is for compatibility with 0.0.101 clients.
                let mut pending_outbound_payments_no_retry: Option<HashMap<PaymentId, HashSet<[u8; 32]>>> = None;
                let mut pending_outbound_payments = None;
-               let mut pending_intercepted_htlcs: Option<HashMap<InterceptId, PendingAddHTLCInfo>> = Some(HashMap::new());
+               let mut pending_intercepted_htlcs: Option<HashMap<InterceptId, PendingAddHTLCInfo>> = Some(new_hash_map());
                let mut received_network_pubkey: Option<PublicKey> = None;
                let mut fake_scid_rand_bytes: Option<[u8; 32]> = None;
                let mut probing_cookie_secret: Option<[u8; 32]> = None;
                let mut claimable_htlc_purposes = None;
                let mut claimable_htlc_onion_fields = None;
-               let mut pending_claiming_payments = Some(HashMap::new());
+               let mut pending_claiming_payments = Some(new_hash_map());
                let mut monitor_update_blocked_actions_per_peer: Option<Vec<(_, BTreeMap<_, Vec<_>>)>> = Some(Vec::new());
                let mut events_override = None;
                let mut in_flight_monitor_updates: Option<HashMap<(PublicKey, OutPoint), Vec<ChannelMonitorUpdate>>> = None;
@@ -10560,7 +11295,7 @@ where
                if pending_outbound_payments.is_none() && pending_outbound_payments_no_retry.is_none() {
                        pending_outbound_payments = Some(pending_outbound_payments_compat);
                } else if pending_outbound_payments.is_none() {
-                       let mut outbounds = HashMap::new();
+                       let mut outbounds = new_hash_map();
                        for (id, session_privs) in pending_outbound_payments_no_retry.unwrap().drain() {
                                outbounds.insert(id, PendingOutboundPayment::Legacy { session_privs });
                        }
@@ -10591,12 +11326,13 @@ where
                                $chan_in_flight_upds.retain(|upd| upd.update_id > $monitor.get_latest_update_id());
                                for update in $chan_in_flight_upds.iter() {
                                        log_trace!($logger, "Replaying ChannelMonitorUpdate {} for {}channel {}",
-                                               update.update_id, $channel_info_log, &$funding_txo.to_channel_id());
+                                               update.update_id, $channel_info_log, &$monitor.channel_id());
                                        max_in_flight_update_id = cmp::max(max_in_flight_update_id, update.update_id);
                                        pending_background_events.push(
                                                BackgroundEvent::MonitorUpdateRegeneratedOnStartup {
                                                        counterparty_node_id: $counterparty_node_id,
                                                        funding_txo: $funding_txo,
+                                                       channel_id: $monitor.channel_id(),
                                                        update: update.clone(),
                                                });
                                }
@@ -10607,7 +11343,7 @@ where
                                        pending_background_events.push(
                                                BackgroundEvent::MonitorUpdatesComplete {
                                                        counterparty_node_id: $counterparty_node_id,
-                                                       channel_id: $funding_txo.to_channel_id(),
+                                                       channel_id: $monitor.channel_id(),
                                                });
                                }
                                if $peer_state.in_flight_monitor_updates.insert($funding_txo, $chan_in_flight_upds).is_some() {
@@ -10661,21 +11397,22 @@ where
 
                if let Some(in_flight_upds) = in_flight_monitor_updates {
                        for ((counterparty_id, funding_txo), mut chan_in_flight_updates) in in_flight_upds {
-                               let logger = WithContext::from(&args.logger, Some(counterparty_id), Some(funding_txo.to_channel_id()));
+                               let channel_id = funding_txo_to_channel_id.get(&funding_txo).copied();
+                               let logger = WithContext::from(&args.logger, Some(counterparty_id), channel_id);
                                if let Some(monitor) = args.channel_monitors.get(&funding_txo) {
                                        // Now that we've removed all the in-flight monitor updates for channels that are
                                        // still open, we need to replay any monitor updates that are for closed channels,
                                        // creating the neccessary peer_state entries as we go.
                                        let peer_state_mutex = per_peer_state.entry(counterparty_id).or_insert_with(|| {
-                                               Mutex::new(peer_state_from_chans(HashMap::new()))
+                                               Mutex::new(peer_state_from_chans(new_hash_map()))
                                        });
                                        let mut peer_state = peer_state_mutex.lock().unwrap();
                                        handle_in_flight_updates!(counterparty_id, chan_in_flight_updates,
                                                funding_txo, monitor, peer_state, logger, "closed ");
                                } else {
                                        log_error!(logger, "A ChannelMonitor is missing even though we have in-flight updates for it! This indicates a potentially-critical violation of the chain::Watch API!");
-                                       log_error!(logger, " The ChannelMonitor for channel {} is missing.",
-                                               &funding_txo.to_channel_id());
+                                       log_error!(logger, " The ChannelMonitor for channel {} is missing.", if let Some(channel_id) =
+                                               channel_id { channel_id.to_string() } else { format!("with outpoint {}", funding_txo) } );
                                        log_error!(logger, " The chain::Watch API *requires* that monitors are persisted durably before returning,");
                                        log_error!(logger, " client applications must ensure that ChannelMonitor data is always available and the latest to avoid funds loss!");
                                        log_error!(logger, " Without the latest ChannelMonitor we cannot continue without risking funds.");
@@ -10728,7 +11465,7 @@ where
                                                                                retry_strategy: None,
                                                                                attempts: PaymentAttempts::new(),
                                                                                payment_params: None,
-                                                                               session_privs: [session_priv_bytes].iter().map(|a| *a).collect(),
+                                                                               session_privs: hash_set_from_iter([session_priv_bytes]),
                                                                                payment_hash: htlc.payment_hash,
                                                                                payment_secret: None, // only used for retries, and we'll never retry on startup
                                                                                payment_metadata: None, // only used for retries, and we'll never retry on startup
@@ -10763,7 +11500,7 @@ where
                                                                                if let HTLCForwardInfo::AddHTLC(htlc_info) = forward {
                                                                                        if pending_forward_matches_htlc(&htlc_info) {
                                                                                                log_info!(logger, "Removing pending to-forward HTLC with hash {} as it was forwarded to the closed channel {}",
-                                                                                                       &htlc.payment_hash, &monitor.get_funding_txo().0.to_channel_id());
+                                                                                                       &htlc.payment_hash, &monitor.channel_id());
                                                                                                false
                                                                                        } else { true }
                                                                                } else { true }
@@ -10773,7 +11510,7 @@ where
                                                                pending_intercepted_htlcs.as_mut().unwrap().retain(|intercepted_id, htlc_info| {
                                                                        if pending_forward_matches_htlc(&htlc_info) {
                                                                                log_info!(logger, "Removing pending intercepted HTLC with hash {} as it was forwarded to the closed channel {}",
-                                                                                       &htlc.payment_hash, &monitor.get_funding_txo().0.to_channel_id());
+                                                                                       &htlc.payment_hash, &monitor.channel_id());
                                                                                pending_events_read.retain(|(event, _)| {
                                                                                        if let Event::HTLCIntercepted { intercept_id: ev_id, .. } = event {
                                                                                                intercepted_id != ev_id
@@ -10797,6 +11534,7 @@ where
                                                                        let compl_action =
                                                                                EventCompletionAction::ReleaseRAAChannelMonitorUpdate {
                                                                                        channel_funding_outpoint: monitor.get_funding_txo().0,
+                                                                                       channel_id: monitor.channel_id(),
                                                                                        counterparty_node_id: path.hops[0].pubkey,
                                                                                };
                                                                        pending_outbounds.claim_htlc(payment_id, preimage, session_priv,
@@ -10822,7 +11560,7 @@ where
                                                                        // channel_id -> peer map entry).
                                                                        counterparty_opt.is_none(),
                                                                        counterparty_opt.cloned().or(monitor.get_counterparty_node_id()),
-                                                                       monitor.get_funding_txo().0))
+                                                                       monitor.get_funding_txo().0, monitor.channel_id()))
                                                        } else { None }
                                                } else {
                                                        // If it was an outbound payment, we've handled it above - if a preimage
@@ -10852,7 +11590,7 @@ where
                let inbound_pmt_key_material = args.node_signer.get_inbound_payment_key_material();
                let expanded_inbound_key = inbound_payment::ExpandedKey::new(&inbound_pmt_key_material);
 
-               let mut claimable_payments = HashMap::with_capacity(claimable_htlcs_list.len());
+               let mut claimable_payments = hash_map_with_capacity(claimable_htlcs_list.len());
                if let Some(purposes) = claimable_htlc_purposes {
                        if purposes.len() != claimable_htlcs_list.len() {
                                return Err(DecodeError::InvalidValue);
@@ -10925,7 +11663,7 @@ where
                        }
                }
 
-               let mut outbound_scid_aliases = HashSet::new();
+               let mut outbound_scid_aliases = new_hash_set();
                for (_peer_node_id, peer_state_mutex) in per_peer_state.iter_mut() {
                        let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                        let peer_state = &mut *peer_state_lock;
@@ -10995,7 +11733,7 @@ where
                                                // this channel as well. On the flip side, there's no harm in restarting
                                                // without the new monitor persisted - we'll end up right back here on
                                                // restart.
-                                               let previous_channel_id = claimable_htlc.prev_hop.outpoint.to_channel_id();
+                                               let previous_channel_id = claimable_htlc.prev_hop.channel_id;
                                                if let Some(peer_node_id) = outpoint_to_peer.get(&claimable_htlc.prev_hop.outpoint) {
                                                        let peer_state_mutex = per_peer_state.get(peer_node_id).unwrap();
                                                        let mut peer_state_lock = peer_state_mutex.lock().unwrap();
@@ -11028,14 +11766,14 @@ where
                                        for action in actions.iter() {
                                                if let MonitorUpdateCompletionAction::EmitEventAndFreeOtherChannel {
                                                        downstream_counterparty_and_funding_outpoint:
-                                                               Some((blocked_node_id, blocked_channel_outpoint, blocking_action)), ..
+                                                               Some((blocked_node_id, _blocked_channel_outpoint, blocked_channel_id, blocking_action)), ..
                                                } = action {
-                                                       if let Some(blocked_peer_state) = per_peer_state.get(&blocked_node_id) {
+                                                       if let Some(blocked_peer_state) = per_peer_state.get(blocked_node_id) {
                                                                log_trace!(logger,
                                                                        "Holding the next revoke_and_ack from {} until the preimage is durably persisted in the inbound edge's ChannelMonitor",
-                                                                       blocked_channel_outpoint.to_channel_id());
+                                                                       blocked_channel_id);
                                                                blocked_peer_state.lock().unwrap().actions_blocking_raa_monitor_updates
-                                                                       .entry(blocked_channel_outpoint.to_channel_id())
+                                                                       .entry(*blocked_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
@@ -11115,12 +11853,14 @@ where
                        channel_manager.fail_htlc_backwards_internal(&source, &payment_hash, &reason, receiver);
                }
 
-               for (source, preimage, downstream_value, downstream_closed, downstream_node_id, downstream_funding) in pending_claims_to_replay {
+               for (source, preimage, downstream_value, downstream_closed, downstream_node_id, downstream_funding, downstream_channel_id) in pending_claims_to_replay {
                        // We use `downstream_closed` in place of `from_onchain` here just as a guess - we
                        // don't remember in the `ChannelMonitor` where we got a preimage from, but if the
                        // channel is closed we just assume that it probably came from an on-chain claim.
-                       channel_manager.claim_funds_internal(source, preimage, Some(downstream_value),
-                               downstream_closed, true, downstream_node_id, downstream_funding);
+                       channel_manager.claim_funds_internal(source, preimage, Some(downstream_value), None,
+                               downstream_closed, true, downstream_node_id, downstream_funding,
+                               downstream_channel_id, None
+                       );
                }
 
                //TODO: Broadcast channel update for closed channels, but only after we've made a
@@ -11807,8 +12547,8 @@ mod tests {
                }
                let (_nodes_1_update, _none) = get_closing_signed_broadcast!(nodes[1].node, nodes[0].node.get_our_node_id());
 
-               check_closed_event!(nodes[0], 1, ClosureReason::CooperativeClosure, [nodes[1].node.get_our_node_id()], 1000000);
-               check_closed_event!(nodes[1], 1, ClosureReason::CooperativeClosure, [nodes[0].node.get_our_node_id()], 1000000);
+               check_closed_event!(nodes[0], 1, ClosureReason::LocallyInitiatedCooperativeClosure, [nodes[1].node.get_our_node_id()], 1000000);
+               check_closed_event!(nodes[1], 1, ClosureReason::CounterpartyInitiatedCooperativeClosure, [nodes[0].node.get_our_node_id()], 1000000);
        }
 
        fn check_not_connected_to_peer_error<T>(res_err: Result<T, APIError>, expected_public_key: PublicKey) {
@@ -11940,14 +12680,15 @@ mod tests {
                                check_added_monitors!(nodes[0], 1);
                                expect_channel_pending_event(&nodes[0], &nodes[1].node.get_our_node_id());
                        }
-                       open_channel_msg.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
+                       open_channel_msg.common_fields.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
                }
 
                // A MAX_UNFUNDED_CHANS_PER_PEER + 1 channel will be summarily rejected
-               open_channel_msg.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
+               open_channel_msg.common_fields.temporary_channel_id = ChannelId::temporary_from_entropy_source(
+                       &nodes[0].keys_manager);
                nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
                assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
-                       open_channel_msg.temporary_channel_id);
+                       open_channel_msg.common_fields.temporary_channel_id);
 
                // Further, because all of our channels with nodes[0] are inbound, and none of them funded,
                // it doesn't count as a "protected" peer, i.e. it counts towards the MAX_NO_CHANNEL_PEERS
@@ -11995,11 +12736,11 @@ mod tests {
                for i in 0..super::MAX_UNFUNDED_CHANNEL_PEERS - 1 {
                        nodes[1].node.handle_open_channel(&peer_pks[i], &open_channel_msg);
                        get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, peer_pks[i]);
-                       open_channel_msg.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
+                       open_channel_msg.common_fields.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
                }
                nodes[1].node.handle_open_channel(&last_random_pk, &open_channel_msg);
                assert_eq!(get_err_msg(&nodes[1], &last_random_pk).channel_id,
-                       open_channel_msg.temporary_channel_id);
+                       open_channel_msg.common_fields.temporary_channel_id);
 
                // Of course, however, outbound channels are always allowed
                nodes[1].node.create_channel(last_random_pk, 100_000, 0, 42, None, None).unwrap();
@@ -12035,14 +12776,14 @@ mod tests {
                for _ in 0..super::MAX_UNFUNDED_CHANS_PER_PEER {
                        nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
                        get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[0].node.get_our_node_id());
-                       open_channel_msg.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
+                       open_channel_msg.common_fields.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
                }
 
                // Once we have MAX_UNFUNDED_CHANS_PER_PEER unfunded channels, new inbound channels will be
                // rejected.
                nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
                assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
-                       open_channel_msg.temporary_channel_id);
+                       open_channel_msg.common_fields.temporary_channel_id);
 
                // but we can still open an outbound channel.
                nodes[1].node.create_channel(nodes[0].node.get_our_node_id(), 100_000, 0, 42, None, None).unwrap();
@@ -12051,7 +12792,7 @@ mod tests {
                // but even with such an outbound channel, additional inbound channels will still fail.
                nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
                assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
-                       open_channel_msg.temporary_channel_id);
+                       open_channel_msg.common_fields.temporary_channel_id);
        }
 
        #[test]
@@ -12087,7 +12828,7 @@ mod tests {
                                _ => panic!("Unexpected event"),
                        }
                        get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, random_pk);
-                       open_channel_msg.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
+                       open_channel_msg.common_fields.temporary_channel_id = ChannelId::temporary_from_entropy_source(&nodes[0].keys_manager);
                }
 
                // If we try to accept a channel from another peer non-0conf it will fail.
@@ -12109,7 +12850,7 @@ mod tests {
                        _ => panic!("Unexpected event"),
                }
                assert_eq!(get_err_msg(&nodes[1], &last_random_pk).channel_id,
-                       open_channel_msg.temporary_channel_id);
+                       open_channel_msg.common_fields.temporary_channel_id);
 
                // ...however if we accept the same channel 0conf it should work just fine.
                nodes[1].node.handle_open_channel(&last_random_pk, &open_channel_msg);
@@ -12143,7 +12884,7 @@ mod tests {
                };
                // Check that if the amount we received + the penultimate hop extra fee is less than the sender
                // intended amount, we fail the payment.
-               let current_height: u32 = node[0].node.best_block.read().unwrap().height();
+               let current_height: u32 = node[0].node.best_block.read().unwrap().height;
                if let Err(crate::ln::channelmanager::InboundHTLCErr { err_code, .. }) =
                        create_recv_pending_htlc_info(hop_data, [0; 32], PaymentHash([0; 32]),
                                sender_intended_amt_msat - extra_fee_msat - 1, 42, None, true, Some(extra_fee_msat),
@@ -12163,7 +12904,7 @@ mod tests {
                        }),
                        custom_tlvs: Vec::new(),
                };
-               let current_height: u32 = node[0].node.best_block.read().unwrap().height();
+               let current_height: u32 = node[0].node.best_block.read().unwrap().height;
                assert!(create_recv_pending_htlc_info(hop_data, [0; 32], PaymentHash([0; 32]),
                        sender_intended_amt_msat - extra_fee_msat, 42, None, true, Some(extra_fee_msat),
                        current_height, node[0].node.default_configuration.accept_mpp_keysend).is_ok());
@@ -12176,7 +12917,7 @@ mod tests {
                let node_chanmgr = create_node_chanmgrs(1, &node_cfg, &[None]);
                let node = create_network(1, &node_cfg, &node_chanmgr);
 
-               let current_height: u32 = node[0].node.best_block.read().unwrap().height();
+               let current_height: u32 = node[0].node.best_block.read().unwrap().height;
                let result = create_recv_pending_htlc_info(msgs::InboundOnionPayload::Receive {
                        sender_intended_htlc_amt_msat: 100,
                        cltv_expiry_height: 22,
@@ -12254,7 +12995,7 @@ mod tests {
 
                nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, 0, 0, None, None).unwrap();
                let open_channel_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
-               assert!(open_channel_msg.channel_type.as_ref().unwrap().supports_anchors_zero_fee_htlc_tx());
+               assert!(open_channel_msg.common_fields.channel_type.as_ref().unwrap().supports_anchors_zero_fee_htlc_tx());
 
                nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
                let events = nodes[1].node.get_and_clear_pending_events();
@@ -12269,7 +13010,7 @@ mod tests {
                nodes[0].node.handle_error(&nodes[1].node.get_our_node_id(), &error_msg);
 
                let open_channel_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
-               assert!(!open_channel_msg.channel_type.unwrap().supports_anchors_zero_fee_htlc_tx());
+               assert!(!open_channel_msg.common_fields.channel_type.unwrap().supports_anchors_zero_fee_htlc_tx());
 
                // Since nodes[1] should not have accepted the channel, it should
                // not have generated any events.
@@ -12458,7 +13199,7 @@ mod tests {
 
 
                let (scid_1, scid_2) = (42, 43);
-               let mut forward_htlcs = HashMap::new();
+               let mut forward_htlcs = new_hash_map();
                forward_htlcs.insert(scid_1, dummy_htlcs_1.clone());
                forward_htlcs.insert(scid_2, dummy_htlcs_2.clone());
 
@@ -12602,7 +13343,7 @@ pub mod bench {
 
                assert_eq!(&tx_broadcaster.txn_broadcasted.lock().unwrap()[..], &[tx.clone()]);
 
-               let block = create_dummy_block(BestBlock::from_network(network).block_hash(), 42, vec![tx]);
+               let block = create_dummy_block(BestBlock::from_network(network).block_hash, 42, vec![tx]);
                Listen::block_connected(&node_a, &block, 1);
                Listen::block_connected(&node_b, &block, 1);