Merge pull request #2136 from marctyndel/2023-03-paymentforwarded-expose-amount-forwarded
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 50cdd2a46b318c08db3393a8d42980b4222e1cfe..d591788f64a68209349b2d7b86c269997a63fbab 100644 (file)
@@ -9,7 +9,7 @@
 
 //! The top-level channel management and payment tracking stuff lives here.
 //!
-//! The ChannelManager is the main chunk of logic implementing the lightning protocol and is
+//! The [`ChannelManager`] is the main chunk of logic implementing the lightning protocol and is
 //! responsible for tracking which channels are open, HTLCs are in flight and reestablishing those
 //! upon reconnect to the relevant peer(s).
 //!
@@ -35,6 +35,8 @@ use crate::chain::{Confirm, ChannelMonitorUpdateStatus, Watch, BestBlock};
 use crate::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator, LowerBoundedFeeEstimator};
 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, HTLC_FAIL_BACK_BUFFER, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY, MonitorEvent, CLOSED_CHANNEL_UPDATE_ID};
 use crate::chain::transaction::{OutPoint, TransactionData};
+use crate::events;
+use crate::events::{Event, EventHandler, EventsProvider, MessageSendEvent, MessageSendEventsProvider, ClosureReason, HTLCDestination};
 // Since this struct is returned in `list_channels` methods, expose it here in case users want to
 // construct one themselves.
 use crate::ln::{inbound_payment, PaymentHash, PaymentPreimage, PaymentSecret};
@@ -55,10 +57,9 @@ use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutb
 use crate::ln::wire::Encode;
 use crate::chain::keysinterface::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, ChannelSigner, WriteableEcdsaChannelSigner};
 use crate::util::config::{UserConfig, ChannelConfig};
-use crate::util::events::{Event, EventHandler, EventsProvider, MessageSendEvent, MessageSendEventsProvider, ClosureReason, HTLCDestination};
-use crate::util::events;
 use crate::util::wakers::{Future, Notifier};
 use crate::util::scid_utils::fake_scid;
+use crate::util::string::UntrustedString;
 use crate::util::ser::{BigSize, FixedLengthReader, Readable, ReadableArgs, MaybeReadable, Writeable, Writer, VecWriter};
 use crate::util::logger::{Level, Logger};
 use crate::util::errors::APIError;
@@ -119,7 +120,10 @@ pub(super) struct PendingHTLCInfo {
        pub(super) routing: PendingHTLCRouting,
        pub(super) incoming_shared_secret: [u8; 32],
        payment_hash: PaymentHash,
+       /// Amount received
        pub(super) incoming_amt_msat: Option<u64>, // Added in 0.0.113
+       /// Sender intended amount to forward or receive (actual amount received
+       /// may overshoot this in either case)
        pub(super) outgoing_amt_msat: u64,
        pub(super) outgoing_cltv_value: u32,
 }
@@ -191,14 +195,21 @@ struct ClaimableHTLC {
        cltv_expiry: u32,
        /// The amount (in msats) of this MPP part
        value: u64,
+       /// The amount (in msats) that the sender intended to be sent in this MPP
+       /// part (used for validating total MPP amount)
+       sender_intended_value: u64,
        onion_payload: OnionPayload,
        timer_ticks: u8,
-       /// The sum total of all MPP parts
+       /// The total value received for a payment (sum of all MPP parts if the payment is a MPP).
+       /// Gets set to the amount reported when pushing [`Event::PaymentClaimable`].
+       total_value_received: Option<u64>,
+       /// The sender intended sum total of all MPP parts specified in the onion
        total_msat: u64,
 }
 
 /// A payment identifier used to uniquely identify a payment to LDK.
-/// (C-not exported) as we just use [u8; 32] directly
+///
+/// This is not exported to bindings users as we just use [u8; 32] directly
 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
 pub struct PaymentId(pub [u8; 32]);
 
@@ -216,7 +227,8 @@ impl Readable for PaymentId {
 }
 
 /// An identifier used to uniquely identify an intercepted HTLC to LDK.
-/// (C-not exported) as we just use [u8; 32] directly
+///
+/// This is not exported to bindings users as we just use [u8; 32] directly
 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
 pub struct InterceptId(pub [u8; 32]);
 
@@ -275,11 +287,6 @@ pub(crate) enum HTLCSource {
                first_hop_htlc_msat: u64,
                payment_id: PaymentId,
                payment_secret: Option<PaymentSecret>,
-               /// Note that this is now "deprecated" - we write it for forwards (and read it for
-               /// backwards) compatibility reasons, but prefer to use the data in the
-               /// [`super::outbound_payment`] module, which stores per-payment data once instead of in
-               /// each HTLC.
-               payment_params: Option<PaymentParameters>,
        },
 }
 #[allow(clippy::derive_hash_xor_eq)] // Our Hash is faithful to the data, we just don't have SecretKey::hash
@@ -290,14 +297,13 @@ impl core::hash::Hash for HTLCSource {
                                0u8.hash(hasher);
                                prev_hop_data.hash(hasher);
                        },
-                       HTLCSource::OutboundRoute { path, session_priv, payment_id, payment_secret, first_hop_htlc_msat, payment_params } => {
+                       HTLCSource::OutboundRoute { path, session_priv, payment_id, payment_secret, first_hop_htlc_msat } => {
                                1u8.hash(hasher);
                                path.hash(hasher);
                                session_priv[..].hash(hasher);
                                payment_id.hash(hasher);
                                payment_secret.hash(hasher);
                                first_hop_htlc_msat.hash(hasher);
-                               payment_params.hash(hasher);
                        },
                }
        }
@@ -312,7 +318,6 @@ impl HTLCSource {
                        first_hop_htlc_msat: 0,
                        payment_id: PaymentId([2; 32]),
                        payment_secret: None,
-                       payment_params: None,
                }
        }
 }
@@ -566,15 +571,16 @@ struct PendingInboundPayment {
        min_value_msat: Option<u64>,
 }
 
-/// SimpleArcChannelManager is useful when you need a ChannelManager with a static lifetime, e.g.
-/// when you're using lightning-net-tokio (since tokio::spawn requires parameters with static
+/// [`SimpleArcChannelManager`] is useful when you need a [`ChannelManager`] with a static lifetime, e.g.
+/// when you're using `lightning-net-tokio` (since `tokio::spawn` requires parameters with static
 /// lifetimes). Other times you can afford a reference, which is more efficient, in which case
-/// SimpleRefChannelManager is the more appropriate type. Defining these type aliases prevents
-/// issues such as overly long function definitions. Note that the ChannelManager can take any type
-/// that implements KeysInterface or Router for its keys manager and router, respectively, but this
-/// type alias chooses the concrete types of KeysManager and DefaultRouter.
+/// [`SimpleRefChannelManager`] is the more appropriate type. Defining these type aliases prevents
+/// issues such as overly long function definitions. Note that the `ChannelManager` can take any type
+/// that implements [`NodeSigner`], [`EntropySource`], and [`SignerProvider`] for its keys manager,
+/// or, respectively, [`Router`] for its router, but this type alias chooses the concrete types
+/// of [`KeysManager`] and [`DefaultRouter`].
 ///
-/// (C-not exported) as Arcs don't make sense in bindings
+/// This is not exported to bindings users as Arcs don't make sense in bindings
 pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<
        Arc<M>,
        Arc<T>,
@@ -590,50 +596,49 @@ pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<
        Arc<L>
 >;
 
-/// SimpleRefChannelManager is a type alias for a ChannelManager reference, and is the reference
-/// counterpart to the SimpleArcChannelManager type alias. Use this type by default when you don't
+/// [`SimpleRefChannelManager`] is a type alias for a ChannelManager reference, and is the reference
+/// counterpart to the [`SimpleArcChannelManager`] type alias. Use this type by default when you don't
 /// need a ChannelManager with a static lifetime. You'll need a static lifetime in cases such as
-/// usage of lightning-net-tokio (since tokio::spawn requires parameters with static lifetimes).
+/// usage of lightning-net-tokio (since `tokio::spawn` requires parameters with static lifetimes).
 /// But if this is not necessary, using a reference is more efficient. Defining these type aliases
 /// issues such as overly long function definitions. Note that the ChannelManager can take any type
-/// that implements KeysInterface or Router for its keys manager and router, respectively, but this
-/// type alias chooses the concrete types of KeysManager and DefaultRouter.
+/// that implements [`NodeSigner`], [`EntropySource`], and [`SignerProvider`] for its keys manager,
+/// or, respectively, [`Router`]  for its router, but this type alias chooses the concrete types
+/// of [`KeysManager`] and [`DefaultRouter`].
 ///
-/// (C-not exported) as Arcs don't make sense in bindings
+/// This is not exported to bindings users as Arcs don't make sense in bindings
 pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> = ChannelManager<&'a M, &'b T, &'c KeysManager, &'c KeysManager, &'c KeysManager, &'d F, &'e DefaultRouter<&'f NetworkGraph<&'g L>, &'g L, &'h Mutex<ProbabilisticScorer<&'f NetworkGraph<&'g L>, &'g L>>>, &'g L>;
 
 /// 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.
 ///
-/// Implements ChannelMessageHandler, handling the multi-channel parts and passing things through
+/// Implements [`ChannelMessageHandler`], handling the multi-channel parts and passing things through
 /// to individual Channels.
 ///
-/// Implements Writeable to write out all channel state to disk. Implies peer_disconnected() for
+/// 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
-/// serialized). This will result in any channels which have not yet exchanged funding_created (ie
-/// called funding_transaction_generated for outbound channels).
+/// serialized). This will result in any channels which have not yet exchanged [`funding_created`] (i.e.,
+/// called [`funding_transaction_generated`] for outbound channels) being closed.
 ///
-/// Note that you can be a bit lazier about writing out ChannelManager than you can be with
-/// ChannelMonitors. With ChannelMonitors you MUST write each monitor update out to disk before
-/// returning from chain::Watch::watch_/update_channel, with ChannelManagers, writing updates
-/// happens out-of-band (and will prevent any other ChannelManager operations from occurring during
+/// Note that you can be a bit lazier about writing out `ChannelManager` than you can be with
+/// [`ChannelMonitor`]. With [`ChannelMonitor`] you MUST write each monitor update out to disk before
+/// returning from [`chain::Watch::watch_channel`]/[`update_channel`], with ChannelManagers, writing updates
+/// happens out-of-band (and will prevent any other `ChannelManager` operations from occurring during
 /// the serialization process). If the deserialized version is out-of-date compared to the
-/// ChannelMonitors passed by reference to read(), those channels will be force-closed based on the
-/// ChannelMonitor state and no funds will be lost (mod on-chain transaction fees).
+/// [`ChannelMonitor`] passed by reference to [`read`], those channels will be force-closed based on the
+/// `ChannelMonitor` state and no funds will be lost (mod on-chain transaction fees).
 ///
-/// Note that the deserializer is only implemented for (BlockHash, ChannelManager), which
-/// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
-/// the "reorg path" (ie call block_disconnected() until you get to a common block and then call
-/// block_connected() to step towards your best block) upon deserialization before using the
-/// object!
+/// Note that the deserializer is only implemented for `(`[`BlockHash`]`, `[`ChannelManager`]`)`, which
+/// 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.
 ///
-/// 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
+/// 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.
+/// [`timer_tick_occurred`] roughly once per minute, though it doesn't have to be perfect.
 ///
-/// To avoid trivial DoS issues, ChannelManager limits the number of inbound connections and
+/// 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
 /// many peers with unfunded channels.
@@ -642,11 +647,20 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> = C
 /// 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.
 ///
-/// 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
+/// 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.
+///
+/// [`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:
 // The tree structure below illustrates the lock order requirements for the different locks of the
@@ -1047,7 +1061,7 @@ pub struct ChannelCounterparty {
        pub outbound_htlc_maximum_msat: Option<u64>,
 }
 
-/// Details of a channel, as returned by ChannelManager::list_channels and ChannelManager::list_usable_channels
+/// Details of a channel, as returned by [`ChannelManager::list_channels`] and [`ChannelManager::list_usable_channels`]
 #[derive(Clone, Debug, PartialEq)]
 pub struct ChannelDetails {
        /// The channel's ID (prior to funding transaction generation, this is a random 32 bytes,
@@ -1118,6 +1132,11 @@ pub struct ChannelDetails {
        /// inbound. This may be zero for inbound channels serialized with LDK versions prior to
        /// 0.0.113.
        pub user_channel_id: u128,
+       /// The currently negotiated fee rate denominated in satoshi per 1000 weight units,
+       /// which is applied to commitment and HTLC transactions.
+       ///
+       /// This value will be `None` for objects serialized with LDK versions prior to 0.0.115.
+       pub feerate_sat_per_1000_weight: Option<u32>,
        /// Our total balance.  This is the amount we would get if we close the channel.
        /// This value is not exact. Due to various in-flight changes and feerate changes, exactly this
        /// amount is not likely to be recoverable on close.
@@ -1260,6 +1279,7 @@ impl ChannelDetails {
                        outbound_scid_alias: if channel.is_usable() { Some(channel.outbound_scid_alias()) } else { None },
                        inbound_scid_alias: channel.latest_inbound_scid_alias(),
                        channel_value_satoshis: channel.get_value_satoshis(),
+                       feerate_sat_per_1000_weight: Some(channel.get_feerate_sat_per_1000_weight()),
                        unspendable_punishment_reserve: to_self_reserve_satoshis,
                        balance_msat: balance.balance_msat,
                        inbound_capacity_msat: balance.inbound_capacity_msat,
@@ -1592,16 +1612,21 @@ where
        R::Target: Router,
        L::Target: Logger,
 {
-       /// Constructs a new ChannelManager to hold several channels and route between them.
+       /// Constructs a new `ChannelManager` to hold several channels and route between them.
        ///
        /// This is the main "logic hub" for all channel-related actions, and implements
-       /// ChannelMessageHandler.
+       /// [`ChannelMessageHandler`].
        ///
        /// Non-proportional fees are fixed according to our risk using the provided fee estimator.
        ///
-       /// Users need to notify the new ChannelManager when a new block is connected or
-       /// disconnected using its `block_connected` and `block_disconnected` methods, starting
-       /// from after `params.latest_hash`.
+       /// Users need to notify the new `ChannelManager` when a new block is connected or
+       /// disconnected using its [`block_connected`] and [`block_disconnected`] methods, starting
+       /// from after [`params.best_block.block_hash`]. See [`chain::Listen`] and [`chain::Confirm`] for
+       /// more details.
+       ///
+       /// [`block_connected`]: chain::Listen::block_connected
+       /// [`block_disconnected`]: chain::Listen::block_disconnected
+       /// [`params.best_block.block_hash`]: chain::BestBlock::block_hash
        pub fn new(fee_est: F, chain_monitor: M, tx_broadcaster: T, router: R, logger: L, entropy_source: ES, node_signer: NS, signer_provider: SP, config: UserConfig, params: ChainParameters) -> Self {
                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
@@ -1775,7 +1800,7 @@ where
                res
        }
 
-       /// Gets the list of open channels, in random order. See ChannelDetail field documentation for
+       /// Gets the list of open channels, in random order. See [`ChannelDetails`] field documentation for
        /// more information.
        pub fn list_channels(&self) -> Vec<ChannelDetails> {
                self.list_channels_with_filter(|_| true)
@@ -1928,11 +1953,12 @@ where
        ///    would appear on a force-closure transaction, whichever is lower. We will allow our
        ///    counterparty to pay as much fee as they'd like, however.
        ///
-       /// May generate a SendShutdown message event on success, which should be relayed.
+       /// May generate a [`SendShutdown`] message event on success, which should be relayed.
        ///
        /// [`ChannelConfig::force_close_avoidance_max_fee_satoshis`]: crate::util::config::ChannelConfig::force_close_avoidance_max_fee_satoshis
        /// [`Background`]: crate::chain::chaininterface::ConfirmationTarget::Background
        /// [`Normal`]: crate::chain::chaininterface::ConfirmationTarget::Normal
+       /// [`SendShutdown`]: crate::events::MessageSendEvent::SendShutdown
        pub fn close_channel(&self, channel_id: &[u8; 32], counterparty_node_id: &PublicKey) -> Result<(), APIError> {
                self.close_channel_internal(channel_id, counterparty_node_id, None)
        }
@@ -1951,11 +1977,12 @@ where
        ///    transaction feerate below `target_feerate_sat_per_1000_weight` (or the feerate which
        ///    will appear on a force-closure transaction, whichever is lower).
        ///
-       /// May generate a SendShutdown message event on success, which should be relayed.
+       /// May generate a [`SendShutdown`] message event on success, which should be relayed.
        ///
        /// [`ChannelConfig::force_close_avoidance_max_fee_satoshis`]: crate::util::config::ChannelConfig::force_close_avoidance_max_fee_satoshis
        /// [`Background`]: crate::chain::chaininterface::ConfirmationTarget::Background
        /// [`Normal`]: crate::chain::chaininterface::ConfirmationTarget::Normal
+       /// [`SendShutdown`]: crate::events::MessageSendEvent::SendShutdown
        pub fn close_channel_with_target_feerate(&self, channel_id: &[u8; 32], counterparty_node_id: &PublicKey, target_feerate_sats_per_1000_weight: u32) -> Result<(), APIError> {
                self.close_channel_internal(channel_id, counterparty_node_id, Some(target_feerate_sats_per_1000_weight))
        }
@@ -1991,7 +2018,7 @@ where
                        let peer_state = &mut *peer_state_lock;
                        if let hash_map::Entry::Occupied(chan) = peer_state.channel_by_id.entry(channel_id.clone()) {
                                if let Some(peer_msg) = peer_msg {
-                                       self.issue_channel_close_events(chan.get(),ClosureReason::CounterpartyForceClosed { peer_msg: peer_msg.to_string() });
+                                       self.issue_channel_close_events(chan.get(),ClosureReason::CounterpartyForceClosed { peer_msg: UntrustedString(peer_msg.to_string()) });
                                } else {
                                        self.issue_channel_close_events(chan.get(),ClosureReason::HolderForceClosed);
                                }
@@ -2074,9 +2101,9 @@ where
                payment_hash: PaymentHash, amt_msat: u64, cltv_expiry: u32, phantom_shared_secret: Option<[u8; 32]>) -> Result<PendingHTLCInfo, ReceiveError>
        {
                // final_incorrect_cltv_expiry
-               if hop_data.outgoing_cltv_value != cltv_expiry {
+               if hop_data.outgoing_cltv_value > cltv_expiry {
                        return Err(ReceiveError {
-                               msg: "Upstream node set CLTV to the wrong value",
+                               msg: "Upstream node set CLTV to less than the CLTV set by the sender",
                                err_code: 18,
                                err_data: cltv_expiry.to_be_bytes().to_vec()
                        })
@@ -2160,7 +2187,7 @@ where
                        payment_hash,
                        incoming_shared_secret: shared_secret,
                        incoming_amt_msat: Some(amt_msat),
-                       outgoing_amt_msat: amt_msat,
+                       outgoing_amt_msat: hop_data.amt_to_forward,
                        outgoing_cltv_value: hop_data.outgoing_cltv_value,
                })
        }
@@ -2400,13 +2427,16 @@ where
                pending_forward_info
        }
 
-       /// Gets the current channel_update for the given channel. This first checks if the channel is
+       /// Gets the current [`channel_update`] for the given channel. This first checks if the channel is
        /// public, and thus should be called whenever the result is going to be passed out in a
        /// [`MessageSendEvent::BroadcastChannelUpdate`] event.
        ///
-       /// Note that in `internal_closing_signed`, this function is called without the `peer_state`
+       /// Note that in [`internal_closing_signed`], this function is called without the `peer_state`
        /// corresponding to the channel's counterparty locked, as the channel been removed from the
        /// storage and the `peer_state` lock has been dropped.
+       ///
+       /// [`channel_update`]: msgs::ChannelUpdate
+       /// [`internal_closing_signed`]: Self::internal_closing_signed
        fn get_channel_update_for_broadcast(&self, chan: &Channel<<SP::Target as SignerProvider>::Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
                if !chan.should_announce() {
                        return Err(LightningError {
@@ -2421,14 +2451,17 @@ where
                self.get_channel_update_for_unicast(chan)
        }
 
-       /// Gets the current channel_update for the given channel. This does not check if the channel
-       /// is public (only returning an Err if the channel does not yet have an assigned short_id),
+       /// Gets the current [`channel_update`] for the given channel. This does not check if the channel
+       /// is public (only returning an `Err` if the channel does not yet have an assigned SCID),
        /// and thus MUST NOT be called unless the recipient of the resulting message has already
        /// provided evidence that they know about the existence of the channel.
        ///
-       /// Note that through `internal_closing_signed`, this function is called without the
+       /// Note that through [`internal_closing_signed`], this function is called without the
        /// `peer_state`  corresponding to the channel's counterparty locked, as the channel been
        /// removed from the storage and the `peer_state` lock has been dropped.
+       ///
+       /// [`channel_update`]: msgs::ChannelUpdate
+       /// [`internal_closing_signed`]: Self::internal_closing_signed
        fn get_channel_update_for_unicast(&self, chan: &Channel<<SP::Target as SignerProvider>::Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
                log_trace!(self.logger, "Attempting to generate channel update for channel {}", log_bytes!(chan.channel_id()));
                let short_channel_id = match chan.get_short_channel_id().or(chan.latest_inbound_scid_alias()) {
@@ -2467,12 +2500,12 @@ where
        }
 
        #[cfg(test)]
-       pub(crate) fn test_send_payment_along_path(&self, path: &Vec<RouteHop>, payment_params: &Option<PaymentParameters>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
+       pub(crate) fn test_send_payment_along_path(&self, path: &Vec<RouteHop>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
                let _lck = self.total_consistency_lock.read().unwrap();
-               self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv_bytes)
+               self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv_bytes)
        }
 
-       fn send_payment_along_path(&self, path: &Vec<RouteHop>, payment_params: &Option<PaymentParameters>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
+       fn send_payment_along_path(&self, path: &Vec<RouteHop>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
                // The top-level caller should hold the total_consistency_lock read lock.
                debug_assert!(self.total_consistency_lock.try_write().is_err());
 
@@ -2511,7 +2544,6 @@ where
                                                first_hop_htlc_msat: htlc_msat,
                                                payment_id,
                                                payment_secret: payment_secret.clone(),
-                                               payment_params: payment_params.clone(),
                                        }, onion_packet, &self.logger);
                                match break_chan_entry!(self, send_res, chan) {
                                        Some(monitor_update) => {
@@ -2555,7 +2587,7 @@ where
        /// Value parameters are provided via the last hop in route, see documentation for [`RouteHop`]
        /// fields for more info.
        ///
-       /// May generate SendHTLCs message(s) event on success, which should be relayed (e.g. via
+       /// May generate [`UpdateHTLCs`] message(s) event on success, which should be relayed (e.g. via
        /// [`PeerManager::process_events`]).
        ///
        /// # Avoiding Duplicate Payments
@@ -2579,7 +2611,7 @@ where
        ///
        /// # Possible Error States on [`PaymentSendFailure`]
        ///
-       /// Each path may have a different return value, and PaymentSendValue may return a Vec with
+       /// Each path may have a different return value, and [`PaymentSendFailure`] may return a `Vec` with
        /// each entry matching the corresponding-index entry in the route paths, see
        /// [`PaymentSendFailure`] for more info.
        ///
@@ -2592,7 +2624,7 @@ where
        ///  * [`APIError::MonitorUpdateInProgress`] if a new monitor update failure prevented sending the
        ///    relevant updates.
        ///
-       /// Note that depending on the type of the PaymentSendFailure the HTLC may have been
+       /// Note that depending on the type of the [`PaymentSendFailure`] the HTLC may have been
        /// irrevocably committed to on our end. In such a case, do NOT retry the payment with a
        /// different route unless you intend to pay twice!
        ///
@@ -2610,6 +2642,7 @@ where
        ///
        /// [`Event::PaymentSent`]: events::Event::PaymentSent
        /// [`Event::PaymentFailed`]: events::Event::PaymentFailed
+       /// [`UpdateHTLCs`]: events::MessageSendEvent::UpdateHTLCs
        /// [`PeerManager::process_events`]: crate::ln::peer_handler::PeerManager::process_events
        /// [`ChannelMonitorUpdateStatus::InProgress`]: crate::chain::ChannelMonitorUpdateStatus::InProgress
        pub fn send_payment(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId) -> Result<(), PaymentSendFailure> {
@@ -2617,8 +2650,8 @@ where
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
                self.pending_outbound_payments
                        .send_payment_with_route(route, payment_hash, payment_secret, payment_id, &self.entropy_source, &self.node_signer, best_block_height,
-                               |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                               self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                               |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                               self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
        /// Similar to [`ChannelManager::send_payment`], but will automatically find a route based on
@@ -2631,17 +2664,17 @@ where
                                &self.router, self.list_usable_channels(), || self.compute_inflight_htlcs(),
                                &self.entropy_source, &self.node_signer, best_block_height, &self.logger,
                                &self.pending_events,
-                               |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                               self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                               |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                               self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
        #[cfg(test)]
-       fn test_send_payment_internal(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>, onion_session_privs: Vec<[u8; 32]>) -> Result<(), PaymentSendFailure> {
+       pub(super) fn test_send_payment_internal(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>, onion_session_privs: Vec<[u8; 32]>) -> Result<(), PaymentSendFailure> {
                let best_block_height = self.best_block.read().unwrap().height();
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
                self.pending_outbound_payments.test_send_payment_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id, recv_value_msat, onion_session_privs, &self.node_signer, best_block_height,
-                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
        #[cfg(test)]
@@ -2693,8 +2726,8 @@ where
                self.pending_outbound_payments.send_spontaneous_payment_with_route(
                        route, payment_preimage, payment_id, &self.entropy_source, &self.node_signer,
                        best_block_height,
-                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
        /// Similar to [`ChannelManager::send_spontaneous_payment`], but will automatically find a route
@@ -2711,8 +2744,8 @@ where
                        retry_strategy, route_params, &self.router, self.list_usable_channels(),
                        || self.compute_inflight_htlcs(),  &self.entropy_source, &self.node_signer, best_block_height,
                        &self.logger, &self.pending_events,
-                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
        /// Send a payment that is probing the given route for liquidity. We calculate the
@@ -2722,8 +2755,8 @@ where
                let best_block_height = self.best_block.read().unwrap().height();
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
                self.pending_outbound_payments.send_probe(hops, self.probing_cookie_secret, &self.entropy_source, &self.node_signer, best_block_height,
-                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
+                       |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
        }
 
        /// Returns whether a payment with the given [`PaymentHash`] and [`PaymentId`] is, in fact, a
@@ -2823,8 +2856,8 @@ where
        /// implemented by Bitcoin Core wallet. See <https://bitcoinops.org/en/topics/fee-sniping/>
        /// for more details.
        ///
-       /// [`Event::FundingGenerationReady`]: crate::util::events::Event::FundingGenerationReady
-       /// [`Event::ChannelClosed`]: crate::util::events::Event::ChannelClosed
+       /// [`Event::FundingGenerationReady`]: crate::events::Event::FundingGenerationReady
+       /// [`Event::ChannelClosed`]: crate::events::Event::ChannelClosed
        pub fn funding_transaction_generated(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, funding_transaction: Transaction) -> Result<(), APIError> {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
@@ -3234,7 +3267,7 @@ where
                                                        HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
                                                                prev_short_channel_id, prev_htlc_id, prev_funding_outpoint, prev_user_channel_id,
                                                                forward_info: PendingHTLCInfo {
-                                                                       routing, incoming_shared_secret, payment_hash, outgoing_amt_msat, ..
+                                                                       routing, incoming_shared_secret, payment_hash, incoming_amt_msat, outgoing_amt_msat, ..
                                                                }
                                                        }) => {
                                                                let (cltv_expiry, onion_payload, payment_data, phantom_shared_secret) = match routing {
@@ -3248,7 +3281,7 @@ where
                                                                                panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
                                                                        }
                                                                };
-                                                               let claimable_htlc = ClaimableHTLC {
+                                                               let mut claimable_htlc = ClaimableHTLC {
                                                                        prev_hop: HTLCPreviousHopData {
                                                                                short_channel_id: prev_short_channel_id,
                                                                                outpoint: prev_funding_outpoint,
@@ -3256,8 +3289,13 @@ where
                                                                                incoming_packet_shared_secret: incoming_shared_secret,
                                                                                phantom_shared_secret,
                                                                        },
-                                                                       value: outgoing_amt_msat,
+                                                                       // We differentiate the received value from the sender intended value
+                                                                       // if possible so that we don't prematurely mark MPP payments complete
+                                                                       // if routing nodes overpay
+                                                                       value: incoming_amt_msat.unwrap_or(outgoing_amt_msat),
+                                                                       sender_intended_value: outgoing_amt_msat,
                                                                        timer_ticks: 0,
+                                                                       total_value_received: None,
                                                                        total_msat: if let Some(data) = &payment_data { data.total_msat } else { outgoing_amt_msat },
                                                                        cltv_expiry,
                                                                        onion_payload,
@@ -3302,7 +3340,7 @@ where
                                                                                        fail_htlc!(claimable_htlc, payment_hash);
                                                                                        continue
                                                                                }
-                                                                               let (_, htlcs) = claimable_payments.claimable_htlcs.entry(payment_hash)
+                                                                               let (_, ref mut htlcs) = claimable_payments.claimable_htlcs.entry(payment_hash)
                                                                                        .or_insert_with(|| (purpose(), Vec::new()));
                                                                                if htlcs.len() == 1 {
                                                                                        if let OnionPayload::Spontaneous(_) = htlcs[0].onion_payload {
@@ -3311,9 +3349,9 @@ where
                                                                                                continue
                                                                                        }
                                                                                }
-                                                                               let mut total_value = claimable_htlc.value;
+                                                                               let mut total_value = claimable_htlc.sender_intended_value;
                                                                                for htlc in htlcs.iter() {
-                                                                                       total_value += htlc.value;
+                                                                                       total_value += htlc.sender_intended_value;
                                                                                        match &htlc.onion_payload {
                                                                                                OnionPayload::Invoice { .. } => {
                                                                                                        if htlc.total_msat != $payment_data.total_msat {
@@ -3326,18 +3364,24 @@ where
                                                                                                _ => unreachable!(),
                                                                                        }
                                                                                }
-                                                                               if total_value >= msgs::MAX_VALUE_MSAT || total_value > $payment_data.total_msat {
-                                                                                       log_trace!(self.logger, "Failing HTLCs with payment_hash {} as the total value {} ran over expected value {} (or HTLCs were inconsistent)",
-                                                                                               log_bytes!(payment_hash.0), total_value, $payment_data.total_msat);
+                                                                               // The condition determining whether an MPP is complete must
+                                                                               // match exactly the condition used in `timer_tick_occurred`
+                                                                               if total_value >= msgs::MAX_VALUE_MSAT {
+                                                                                       fail_htlc!(claimable_htlc, payment_hash);
+                                                                               } else if total_value - claimable_htlc.sender_intended_value >= $payment_data.total_msat {
+                                                                                       log_trace!(self.logger, "Failing HTLC with payment_hash {} as payment is already claimable",
+                                                                                               log_bytes!(payment_hash.0));
                                                                                        fail_htlc!(claimable_htlc, payment_hash);
-                                                                               } else if total_value == $payment_data.total_msat {
+                                                                               } else if total_value >= $payment_data.total_msat {
                                                                                        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));
                                                                                        new_events.push(events::Event::PaymentClaimable {
                                                                                                receiver_node_id: Some(receiver_node_id),
                                                                                                payment_hash,
                                                                                                purpose: purpose(),
-                                                                                               amount_msat: total_value,
+                                                                                               amount_msat,
                                                                                                via_channel_id: Some(prev_channel_id),
                                                                                                via_user_channel_id: Some(prev_user_channel_id),
                                                                                        });
@@ -3391,13 +3435,15 @@ where
                                                                                                }
                                                                                                match claimable_payments.claimable_htlcs.entry(payment_hash) {
                                                                                                        hash_map::Entry::Vacant(e) => {
+                                                                                                               let amount_msat = claimable_htlc.value;
+                                                                                                               claimable_htlc.total_value_received = Some(amount_msat);
                                                                                                                let purpose = events::PaymentPurpose::SpontaneousPayment(preimage);
                                                                                                                e.insert((purpose.clone(), vec![claimable_htlc]));
                                                                                                                let prev_channel_id = prev_funding_outpoint.to_channel_id();
                                                                                                                new_events.push(events::Event::PaymentClaimable {
                                                                                                                        receiver_node_id: Some(receiver_node_id),
                                                                                                                        payment_hash,
-                                                                                                                       amount_msat: outgoing_amt_msat,
+                                                                                                                       amount_msat,
                                                                                                                        purpose,
                                                                                                                        via_channel_id: Some(prev_channel_id),
                                                                                                                        via_user_channel_id: Some(prev_user_channel_id),
@@ -3447,8 +3493,8 @@ where
                self.pending_outbound_payments.check_retry_payments(&self.router, || self.list_usable_channels(),
                        || self.compute_inflight_htlcs(), &self.entropy_source, &self.node_signer, best_block_height,
                        &self.pending_events, &self.logger,
-                       |path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
-                       self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv));
+                       |path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
+                       self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv));
 
                for (htlc_source, payment_hash, failure_reason, destination) in failed_forwards.drain(..) {
                        self.fail_htlc_backwards_internal(&htlc_source, &payment_hash, &failure_reason, destination);
@@ -3500,18 +3546,18 @@ where
        fn update_channel_fee(&self, chan_id: &[u8; 32], chan: &mut Channel<<SP::Target as SignerProvider>::Signer>, new_feerate: u32) -> NotifyOption {
                if !chan.is_outbound() { return NotifyOption::SkipPersist; }
                // If the feerate has decreased by less than half, don't bother
-               if new_feerate <= chan.get_feerate() && new_feerate * 2 > chan.get_feerate() {
+               if new_feerate <= chan.get_feerate_sat_per_1000_weight() && new_feerate * 2 > chan.get_feerate_sat_per_1000_weight() {
                        log_trace!(self.logger, "Channel {} does not qualify for a feerate change from {} to {}.",
-                               log_bytes!(chan_id[..]), chan.get_feerate(), new_feerate);
+                               log_bytes!(chan_id[..]), chan.get_feerate_sat_per_1000_weight(), new_feerate);
                        return NotifyOption::SkipPersist;
                }
                if !chan.is_live() {
                        log_trace!(self.logger, "Channel {} does not qualify for a feerate change from {} to {} as it cannot currently be updated (probably the peer is disconnected).",
-                               log_bytes!(chan_id[..]), chan.get_feerate(), new_feerate);
+                               log_bytes!(chan_id[..]), chan.get_feerate_sat_per_1000_weight(), new_feerate);
                        return NotifyOption::SkipPersist;
                }
                log_trace!(self.logger, "Channel {} qualifies for a feerate change from {} to {}.",
-                       log_bytes!(chan_id[..]), chan.get_feerate(), new_feerate);
+                       log_bytes!(chan_id[..]), chan.get_feerate_sat_per_1000_weight(), new_feerate);
 
                chan.queue_update_fee(new_feerate, &self.logger);
                NotifyOption::DoPersist
@@ -3546,15 +3592,18 @@ where
        ///
        /// This currently includes:
        ///  * Increasing or decreasing the on-chain feerate estimates for our outbound channels,
-       ///  * Broadcasting `ChannelUpdate` messages if we've been disconnected from our peer for more
+       ///  * Broadcasting [`ChannelUpdate`] messages if we've been disconnected from our peer for more
        ///    than a minute, informing the network that they should no longer attempt to route over
        ///    the channel.
-       ///  * Expiring a channel's previous `ChannelConfig` if necessary to only allow forwarding HTLCs
-       ///    with the current `ChannelConfig`.
+       ///  * Expiring a channel's previous [`ChannelConfig`] if necessary to only allow forwarding HTLCs
+       ///    with the current [`ChannelConfig`].
        ///  * Removing peers which have disconnected but and no longer have any channels.
        ///
-       /// Note that this may cause reentrancy through `chain::Watch::update_channel` calls or feerate
+       /// Note that this may cause reentrancy through [`chain::Watch::update_channel`] calls or feerate
        /// estimate fetches.
+       ///
+       /// [`ChannelUpdate`]: msgs::ChannelUpdate
+       /// [`ChannelConfig`]: crate::util::config::ChannelConfig
        pub fn timer_tick_occurred(&self) {
                PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
                        let mut should_persist = NotifyOption::SkipPersist;
@@ -3654,7 +3703,9 @@ where
                                if let OnionPayload::Invoice { .. } = htlcs[0].onion_payload {
                                        // Check if we've received all the parts we need for an MPP (the value of the parts adds to total_msat).
                                        // In this case we're not going to handle any timeouts of the parts here.
-                                       if htlcs[0].total_msat == htlcs.iter().fold(0, |total, htlc| total + htlc.value) {
+                                       // This condition determining whether the MPP is complete here must match
+                                       // exactly the condition used in `process_pending_htlc_forwards`.
+                                       if htlcs[0].total_msat <= htlcs.iter().fold(0, |total, htlc| total + htlc.sender_intended_value) {
                                                return true;
                                        } else if htlcs.into_iter().any(|htlc| {
                                                htlc.timer_ticks += 1;
@@ -3834,9 +3885,9 @@ where
                // from block_connected which may run during initialization prior to the chain_monitor
                // being fully configured. See the docs for `ChannelManagerReadArgs` for more.
                match source {
-                       HTLCSource::OutboundRoute { ref path, ref session_priv, ref payment_id, ref payment_params, .. } => {
+                       HTLCSource::OutboundRoute { ref path, ref session_priv, ref payment_id, .. } => {
                                if self.pending_outbound_payments.fail_htlc(source, payment_hash, onion_error, path,
-                                       session_priv, payment_id, payment_params, self.probing_cookie_secret, &self.secp_ctx,
+                                       session_priv, payment_id, self.probing_cookie_secret, &self.secp_ctx,
                                        &self.pending_events, &self.logger)
                                { self.push_pending_forwards_ev(); }
                        },
@@ -3880,8 +3931,8 @@ where
        /// event matches your expectation. If you fail to do so and call this method, you may provide
        /// the sender "proof-of-payment" when they did not fulfill the full expected payment.
        ///
-       /// [`Event::PaymentClaimable`]: crate::util::events::Event::PaymentClaimable
-       /// [`Event::PaymentClaimed`]: crate::util::events::Event::PaymentClaimed
+       /// [`Event::PaymentClaimable`]: crate::events::Event::PaymentClaimable
+       /// [`Event::PaymentClaimed`]: crate::events::Event::PaymentClaimed
        /// [`process_pending_events`]: EventsProvider::process_pending_events
        /// [`create_inbound_payment`]: Self::create_inbound_payment
        /// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
@@ -3933,6 +3984,7 @@ where
                // provide the preimage, so worrying too much about the optimal handling isn't worth
                // it.
                let mut claimable_amt_msat = 0;
+               let mut prev_total_msat = None;
                let mut expected_amt_msat = None;
                let mut valid_mpp = true;
                let mut errs = Vec::new();
@@ -3960,14 +4012,22 @@ where
                                break;
                        }
 
-                       if expected_amt_msat.is_some() && expected_amt_msat != Some(htlc.total_msat) {
-                               log_error!(self.logger, "Somehow ended up with an MPP payment with different total amounts - this should not be reachable!");
+                       if prev_total_msat.is_some() && prev_total_msat != Some(htlc.total_msat) {
+                               log_error!(self.logger, "Somehow ended up with an MPP payment with different expected total amounts - this should not be reachable!");
                                debug_assert!(false);
                                valid_mpp = false;
                                break;
                        }
+                       prev_total_msat = Some(htlc.total_msat);
+
+                       if expected_amt_msat.is_some() && expected_amt_msat != htlc.total_value_received {
+                               log_error!(self.logger, "Somehow ended up with an MPP payment with different received total amounts - this should not be reachable!");
+                               debug_assert!(false);
+                               valid_mpp = false;
+                               break;
+                       }
+                       expected_amt_msat = htlc.total_value_received;
 
-                       expected_amt_msat = Some(htlc.total_msat);
                        if let OnionPayload::Spontaneous(_) = &htlc.onion_payload {
                                // We don't currently support MPP for spontaneous payments, so just check
                                // that there's one payment here and move on.
@@ -4124,6 +4184,7 @@ where
                                                                claim_from_onchain_tx: from_onchain,
                                                                prev_channel_id,
                                                                next_channel_id,
+                                                               outbound_amount_forwarded_msat: forwarded_htlc_value_msat,
                                                        }})
                                                } else { None }
                                        });
@@ -5168,7 +5229,7 @@ where
                Ok(())
        }
 
-       /// Process pending events from the `chain::Watch`, returning whether any events were processed.
+       /// Process pending events from the [`chain::Watch`], returning whether any events were processed.
        fn process_pending_monitor_events(&self) -> bool {
                debug_assert!(self.total_consistency_lock.try_write().is_err()); // Caller holds read lock
 
@@ -6495,8 +6556,8 @@ pub(crate) fn provided_channel_type_features(config: &UserConfig) -> ChannelType
 /// [`ChannelManager`].
 pub fn provided_init_features(_config: &UserConfig) -> InitFeatures {
        // Note that if new features are added here which other peers may (eventually) require, we
-       // should also add the corresponding (optional) bit to the ChannelMessageHandler impl for
-       // ErroringMessageHandler.
+       // should also add the corresponding (optional) bit to the [`ChannelMessageHandler`] impl for
+       // [`ErroringMessageHandler`].
        let mut features = InitFeatures::empty();
        features.set_data_loss_protect_optional();
        features.set_upfront_shutdown_script_optional();
@@ -6570,6 +6631,7 @@ impl Writeable for ChannelDetails {
                        (33, self.inbound_htlc_minimum_msat, option),
                        (35, self.inbound_htlc_maximum_msat, option),
                        (37, user_channel_id_high_opt, option),
+                       (39, self.feerate_sat_per_1000_weight, option),
                });
                Ok(())
        }
@@ -6605,6 +6667,7 @@ impl Readable for ChannelDetails {
                        (33, inbound_htlc_minimum_msat, option),
                        (35, inbound_htlc_maximum_msat, option),
                        (37, user_channel_id_high_opt, option),
+                       (39, feerate_sat_per_1000_weight, option),
                });
 
                // `user_channel_id` used to be a single u64 value. In order to remain backwards compatible with
@@ -6638,6 +6701,7 @@ impl Readable for ChannelDetails {
                        is_public: is_public.0.unwrap(),
                        inbound_htlc_minimum_msat,
                        inbound_htlc_maximum_msat,
+                       feerate_sat_per_1000_weight,
                })
        }
 }
@@ -6764,7 +6828,9 @@ impl Writeable for ClaimableHTLC {
                        (0, self.prev_hop, required),
                        (1, self.total_msat, required),
                        (2, self.value, required),
+                       (3, self.sender_intended_value, required),
                        (4, payment_data, option),
+                       (5, self.total_value_received, option),
                        (6, self.cltv_expiry, required),
                        (8, keysend_preimage, option),
                });
@@ -6776,15 +6842,19 @@ impl Readable for ClaimableHTLC {
        fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
                let mut prev_hop = crate::util::ser::RequiredWrapper(None);
                let mut value = 0;
+               let mut sender_intended_value = None;
                let mut payment_data: Option<msgs::FinalOnionHopData> = None;
                let mut cltv_expiry = 0;
+               let mut total_value_received = None;
                let mut total_msat = None;
                let mut keysend_preimage: Option<PaymentPreimage> = None;
                read_tlv_fields!(reader, {
                        (0, prev_hop, required),
                        (1, total_msat, option),
                        (2, value, required),
+                       (3, sender_intended_value, option),
                        (4, payment_data, option),
+                       (5, total_value_received, option),
                        (6, cltv_expiry, required),
                        (8, keysend_preimage, option)
                });
@@ -6812,6 +6882,8 @@ impl Readable for ClaimableHTLC {
                        prev_hop: prev_hop.0.unwrap(),
                        timer_ticks: 0,
                        value,
+                       sender_intended_value: sender_intended_value.unwrap_or(value),
+                       total_value_received,
                        total_msat: total_msat.unwrap(),
                        onion_payload,
                        cltv_expiry,
@@ -6858,7 +6930,6 @@ impl Readable for HTLCSource {
                                        path,
                                        payment_id: payment_id.unwrap(),
                                        payment_secret,
-                                       payment_params,
                                })
                        }
                        1 => Ok(HTLCSource::PreviousHopData(Readable::read(reader)?)),
@@ -6870,7 +6941,7 @@ impl Readable for HTLCSource {
 impl Writeable for HTLCSource {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), crate::io::Error> {
                match self {
-                       HTLCSource::OutboundRoute { ref session_priv, ref first_hop_htlc_msat, ref path, payment_id, payment_secret, payment_params } => {
+                       HTLCSource::OutboundRoute { ref session_priv, ref first_hop_htlc_msat, ref path, payment_id, payment_secret } => {
                                0u8.write(writer)?;
                                let payment_id_opt = Some(payment_id);
                                write_tlv_fields!(writer, {
@@ -6879,7 +6950,7 @@ impl Writeable for HTLCSource {
                                        (2, first_hop_htlc_msat, required),
                                        (3, payment_secret, option),
                                        (4, *path, vec_type),
-                                       (5, payment_params, option),
+                                       (5, None::<PaymentParameters>, option), // payment_params in LDK versions prior to 0.0.115
                                 });
                        }
                        HTLCSource::PreviousHopData(ref field) => {
@@ -7209,7 +7280,7 @@ where
        /// In such cases the latest local transactions will be sent to the tx_broadcaster included in
        /// this struct.
        ///
-       /// (C-not exported) because we have no HashMap bindings
+       /// This is not exported to bindings users because we have no HashMap bindings
        pub channel_monitors: HashMap<OutPoint, &'a mut ChannelMonitor<<SP::Target as SignerProvider>::Signer>>,
 }
 
@@ -7284,6 +7355,7 @@ where
                let mut id_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 channel_closures = Vec::new();
+               let mut pending_background_events = Vec::new();
                for _ in 0..channel_count {
                        let mut channel: Channel<<SP::Target as SignerProvider>::Signer> = Channel::read(reader, (
                                &args.entropy_source, &args.signer_provider, best_block_height, &provided_channel_type_features(&args.default_config)
@@ -7313,9 +7385,11 @@ where
                                        log_error!(args.logger, " The channel will be force-closed and the latest commitment transaction from the ChannelMonitor broadcast.");
                                        log_error!(args.logger, " The ChannelMonitor for channel {} is at update_id {} but the ChannelManager is at update_id {}.",
                                                log_bytes!(channel.channel_id()), monitor.get_latest_update_id(), channel.get_latest_monitor_update_id());
-                                       let (_, mut new_failed_htlcs) = channel.force_shutdown(true);
+                                       let (monitor_update, mut new_failed_htlcs) = channel.force_shutdown(true);
+                                       if let Some(monitor_update) = monitor_update {
+                                               pending_background_events.push(BackgroundEvent::ClosingMonitorUpdate(monitor_update));
+                                       }
                                        failed_htlcs.append(&mut new_failed_htlcs);
-                                       monitor.broadcast_latest_holder_commitment_txn(&args.tx_broadcaster, &args.logger);
                                        channel_closures.push(events::Event::ChannelClosed {
                                                channel_id: channel.channel_id(),
                                                user_channel_id: channel.get_user_id(),
@@ -7380,10 +7454,13 @@ where
                        }
                }
 
-               for (funding_txo, monitor) in args.channel_monitors.iter_mut() {
+               for (funding_txo, _) in args.channel_monitors.iter() {
                        if !funding_txo_set.contains(funding_txo) {
-                               log_info!(args.logger, "Broadcasting latest holder commitment transaction for closed channel {}", log_bytes!(funding_txo.to_channel_id()));
-                               monitor.broadcast_latest_holder_commitment_txn(&args.tx_broadcaster, &args.logger);
+                               let monitor_update = ChannelMonitorUpdate {
+                                       update_id: CLOSED_CHANNEL_UPDATE_ID,
+                                       updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast: true }],
+                               };
+                               pending_background_events.push(BackgroundEvent::ClosingMonitorUpdate((*funding_txo, monitor_update)));
                        }
                }
 
@@ -7436,10 +7513,17 @@ where
                }
 
                let background_event_count: u64 = Readable::read(reader)?;
-               let mut pending_background_events_read: Vec<BackgroundEvent> = Vec::with_capacity(cmp::min(background_event_count as usize, MAX_ALLOC_SIZE/mem::size_of::<BackgroundEvent>()));
                for _ in 0..background_event_count {
                        match <u8 as Readable>::read(reader)? {
-                               0 => pending_background_events_read.push(BackgroundEvent::ClosingMonitorUpdate((Readable::read(reader)?, Readable::read(reader)?))),
+                               0 => {
+                                       let (funding_txo, monitor_update): (OutPoint, ChannelMonitorUpdate) = (Readable::read(reader)?, Readable::read(reader)?);
+                                       if pending_background_events.iter().find(|e| {
+                                               let BackgroundEvent::ClosingMonitorUpdate((pending_funding_txo, pending_monitor_update)) = e;
+                                               *pending_funding_txo == funding_txo && *pending_monitor_update == monitor_update
+                                       }).is_none() {
+                                               pending_background_events.push(BackgroundEvent::ClosingMonitorUpdate((funding_txo, monitor_update)));
+                                       }
+                               }
                                _ => return Err(DecodeError::InvalidValue),
                        }
                }
@@ -7814,7 +7898,7 @@ where
                        per_peer_state: FairRwLock::new(per_peer_state),
 
                        pending_events: Mutex::new(pending_events_read),
-                       pending_background_events: Mutex::new(pending_background_events_read),
+                       pending_background_events: Mutex::new(pending_background_events),
                        total_consistency_lock: RwLock::new(()),
                        persistence_notifier: Notifier::new(),
 
@@ -7847,6 +7931,7 @@ mod tests {
        use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
        use core::time::Duration;
        use core::sync::atomic::Ordering;
+       use crate::events::{Event, HTLCDestination, MessageSendEvent, MessageSendEventsProvider, ClosureReason};
        use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
        use crate::ln::channelmanager::{inbound_payment, PaymentId, PaymentSendFailure, InterceptId};
        use crate::ln::functional_test_utils::*;
@@ -7854,7 +7939,6 @@ mod tests {
        use crate::ln::msgs::ChannelMessageHandler;
        use crate::routing::router::{PaymentParameters, RouteParameters, find_route};
        use crate::util::errors::APIError;
-       use crate::util::events::{Event, HTLCDestination, MessageSendEvent, MessageSendEventsProvider, ClosureReason};
        use crate::util::test_utils;
        use crate::util::config::ChannelConfig;
        use crate::chain::keysinterface::EntropySource;
@@ -7959,7 +8043,7 @@ mod tests {
                // indicates there are more HTLCs coming.
                let cur_height = CHAN_CONFIRM_DEPTH + 1; // route_payment calls send_payment, which adds 1 to the current height. So we do the same here to match.
                let session_privs = nodes[0].node.test_add_new_pending_payment(our_payment_hash, Some(payment_secret), payment_id, &mpp_route).unwrap();
-               nodes[0].node.test_send_payment_along_path(&mpp_route.paths[0], &route.payment_params, &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[0]).unwrap();
+               nodes[0].node.test_send_payment_along_path(&mpp_route.paths[0], &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[0]).unwrap();
                check_added_monitors!(nodes[0], 1);
                let mut events = nodes[0].node.get_and_clear_pending_msg_events();
                assert_eq!(events.len(), 1);
@@ -7989,7 +8073,7 @@ mod tests {
                expect_payment_failed!(nodes[0], our_payment_hash, true);
 
                // Send the second half of the original MPP payment.
-               nodes[0].node.test_send_payment_along_path(&mpp_route.paths[1], &route.payment_params, &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[1]).unwrap();
+               nodes[0].node.test_send_payment_along_path(&mpp_route.paths[1], &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[1]).unwrap();
                check_added_monitors!(nodes[0], 1);
                let mut events = nodes[0].node.get_and_clear_pending_msg_events();
                assert_eq!(events.len(), 1);
@@ -8195,7 +8279,7 @@ mod tests {
                assert!(updates.update_fee.is_none());
                nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
 
-               nodes[1].logger.assert_log_contains("lightning::ln::channelmanager".to_string(), "Payment preimage didn't match payment hash".to_string(), 1);
+               nodes[1].logger.assert_log_contains("lightning::ln::channelmanager", "Payment preimage didn't match payment hash", 1);
        }
 
        #[test]
@@ -8238,7 +8322,7 @@ mod tests {
                assert!(updates.update_fee.is_none());
                nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
 
-               nodes[1].logger.assert_log_contains("lightning::ln::channelmanager".to_string(), "We don't support MPP keysend payments".to_string(), 1);
+               nodes[1].logger.assert_log_contains("lightning::ln::channelmanager", "We don't support MPP keysend payments", 1);
        }
 
        #[test]
@@ -8266,7 +8350,8 @@ mod tests {
 
                match nodes[0].node.send_payment(&route, payment_hash, &None, PaymentId(payment_hash.0)).unwrap_err() {
                        PaymentSendFailure::ParameterError(APIError::APIMisuseError { ref err }) => {
-                               assert!(regex::Regex::new(r"Payment secret is required for multi-path payments").unwrap().is_match(err))                        },
+                               assert!(regex::Regex::new(r"Payment secret is required for multi-path payments").unwrap().is_match(err))
+                       },
                        _ => panic!("unexpected error")
                }
        }
@@ -8326,7 +8411,7 @@ mod tests {
                match inbound_payment::verify(bad_payment_hash, &payment_data, nodes[0].node.highest_seen_timestamp.load(Ordering::Acquire) as u64, &nodes[0].node.inbound_payment_key, &nodes[0].logger) {
                        Ok(_) => panic!("Unexpected ok"),
                        Err(()) => {
-                               nodes[0].logger.assert_log_contains("lightning::ln::inbound_payment".to_string(), "Failing HTLC with user-generated payment_hash".to_string(), 1);
+                               nodes[0].logger.assert_log_contains("lightning::ln::inbound_payment", "Failing HTLC with user-generated payment_hash", 1);
                        }
                }
 
@@ -8543,7 +8628,7 @@ mod tests {
                // A MAX_UNFUNDED_CHANS_PER_PEER + 1 channel will be summarily rejected
                open_channel_msg.temporary_channel_id = nodes[0].keys_manager.get_secure_random_bytes();
                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,
+               assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
                        open_channel_msg.temporary_channel_id);
 
                // Further, because all of our channels with nodes[0] are inbound, and none of them funded,
@@ -8590,7 +8675,7 @@ mod tests {
                        open_channel_msg.temporary_channel_id = nodes[0].keys_manager.get_secure_random_bytes();
                }
                nodes[1].node.handle_open_channel(&last_random_pk, &open_channel_msg);
-               assert_eq!(get_err_msg!(nodes[1], last_random_pk).channel_id,
+               assert_eq!(get_err_msg(&nodes[1], &last_random_pk).channel_id,
                        open_channel_msg.temporary_channel_id);
 
                // Of course, however, outbound channels are always allowed
@@ -8632,7 +8717,7 @@ mod tests {
                // 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,
+               assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
                        open_channel_msg.temporary_channel_id);
 
                // but we can still open an outbound channel.
@@ -8641,7 +8726,7 @@ 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,
+               assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
                        open_channel_msg.temporary_channel_id);
        }
 
@@ -8697,7 +8782,7 @@ mod tests {
                        }
                        _ => panic!("Unexpected event"),
                }
-               assert_eq!(get_err_msg!(nodes[1], last_random_pk).channel_id,
+               assert_eq!(get_err_msg(&nodes[1], &last_random_pk).channel_id,
                        open_channel_msg.temporary_channel_id);
 
                // ...however if we accept the same channel 0conf it should work just fine.
@@ -8739,7 +8824,7 @@ mod tests {
                        _ => panic!("Unexpected event"),
                }
 
-               let error_msg = get_err_msg!(nodes[1], nodes[0].node.get_our_node_id());
+               let error_msg = get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id());
                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());
@@ -8754,6 +8839,7 @@ pub mod bench {
        use crate::chain::Listen;
        use crate::chain::chainmonitor::{ChainMonitor, Persist};
        use crate::chain::keysinterface::{EntropySource, KeysManager, InMemorySigner};
+       use crate::events::{Event, MessageSendEvent, MessageSendEventsProvider};
        use crate::ln::channelmanager::{self, BestBlock, ChainParameters, ChannelManager, PaymentHash, PaymentPreimage, PaymentId};
        use crate::ln::functional_test_utils::*;
        use crate::ln::msgs::{ChannelMessageHandler, Init};
@@ -8761,7 +8847,6 @@ pub mod bench {
        use crate::routing::router::{PaymentParameters, get_route};
        use crate::util::test_utils;
        use crate::util::config::UserConfig;
-       use crate::util::events::{Event, MessageSendEvent, MessageSendEventsProvider};
 
        use bitcoin::hashes::Hash;
        use bitcoin::hashes::sha256::Hash as Sha256;
@@ -8905,7 +8990,7 @@ pub mod bench {
                                let payment_event = SendEvent::from_event($node_a.get_and_clear_pending_msg_events().pop().unwrap());
                                $node_b.handle_update_add_htlc(&$node_a.get_our_node_id(), &payment_event.msgs[0]);
                                $node_b.handle_commitment_signed(&$node_a.get_our_node_id(), &payment_event.commitment_msg);
-                               let (raa, cs) = get_revoke_commit_msgs!(NodeHolder { node: &$node_b }, $node_a.get_our_node_id());
+                               let (raa, cs) = do_get_revoke_commit_msgs!(NodeHolder { node: &$node_b }, &$node_a.get_our_node_id());
                                $node_a.handle_revoke_and_ack(&$node_b.get_our_node_id(), &raa);
                                $node_a.handle_commitment_signed(&$node_b.get_our_node_id(), &cs);
                                $node_b.handle_revoke_and_ack(&$node_a.get_our_node_id(), &get_event_msg!(NodeHolder { node: &$node_a }, MessageSendEvent::SendRevokeAndACK, $node_b.get_our_node_id()));
@@ -8924,7 +9009,7 @@ pub mod bench {
                                        _ => panic!("Failed to generate claim event"),
                                }
 
-                               let (raa, cs) = get_revoke_commit_msgs!(NodeHolder { node: &$node_a }, $node_b.get_our_node_id());
+                               let (raa, cs) = do_get_revoke_commit_msgs!(NodeHolder { node: &$node_a }, &$node_b.get_our_node_id());
                                $node_b.handle_revoke_and_ack(&$node_a.get_our_node_id(), &raa);
                                $node_b.handle_commitment_signed(&$node_a.get_our_node_id(), &cs);
                                $node_a.handle_revoke_and_ack(&$node_b.get_our_node_id(), &get_event_msg!(NodeHolder { node: &$node_b }, MessageSendEvent::SendRevokeAndACK, $node_a.get_our_node_id()));