Move DefaultRouter to router module
[rust-lightning] / lightning / src / ln / channelmanager.rs
index ba3729207077474ec711ac2caa7647881155dd99..b22dacdd686d1ceca2511c8b44046c14fa7e787f 100644 (file)
@@ -46,14 +46,14 @@ use crate::ln::channel::{Channel, ChannelError, ChannelUpdateStatus, UpdateFulfi
 use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
 #[cfg(any(feature = "_test_utils", test))]
 use crate::ln::features::InvoiceFeatures;
-use crate::routing::router::{PaymentParameters, Route, RouteHop, RoutePath, RouteParameters};
+use crate::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, RoutePath, RouteParameters};
 use crate::ln::msgs;
 use crate::ln::onion_utils;
 use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError, MAX_VALUE_MSAT};
 use crate::ln::wire::Encode;
 use crate::chain::keysinterface::{Sign, KeysInterface, KeysManager, Recipient};
 use crate::util::config::{UserConfig, ChannelConfig};
-use crate::util::events::{EventHandler, EventsProvider, MessageSendEvent, MessageSendEventsProvider, ClosureReason, HTLCDestination};
+use crate::util::events::{Event, EventHandler, EventsProvider, MessageSendEvent, MessageSendEventsProvider, ClosureReason, HTLCDestination};
 use crate::util::{byte_utils, events};
 use crate::util::wakers::{Future, Notifier};
 use crate::util::scid_utils::fake_scid;
@@ -112,8 +112,8 @@ pub(super) struct PendingHTLCInfo {
        pub(super) routing: PendingHTLCRouting,
        pub(super) incoming_shared_secret: [u8; 32],
        payment_hash: PaymentHash,
-       pub(super) amt_to_forward: u64,
-       pub(super) amt_incoming: Option<u64>, // Added in 0.0.113
+       pub(super) incoming_amt_msat: Option<u64>, // Added in 0.0.113
+       pub(super) outgoing_amt_msat: u64,
        pub(super) outgoing_cltv_value: u32,
 }
 
@@ -292,7 +292,7 @@ type ShutdownResult = (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource
 
 struct MsgHandleErrInternal {
        err: msgs::LightningError,
-       chan_id: Option<([u8; 32], u64)>, // If Some a channel of ours has been closed
+       chan_id: Option<([u8; 32], u128)>, // If Some a channel of ours has been closed
        shutdown_finish: Option<(ShutdownResult, Option<msgs::ChannelUpdate>)>,
 }
 impl MsgHandleErrInternal {
@@ -328,7 +328,7 @@ impl MsgHandleErrInternal {
                Self { err, chan_id: None, shutdown_finish: None }
        }
        #[inline]
-       fn from_finish_shutdown(err: String, channel_id: [u8; 32], user_channel_id: u64, shutdown_res: ShutdownResult, channel_update: Option<msgs::ChannelUpdate>) -> Self {
+       fn from_finish_shutdown(err: String, channel_id: [u8; 32], user_channel_id: u128, shutdown_res: ShutdownResult, channel_update: Option<msgs::ChannelUpdate>) -> Self {
                Self {
                        err: LightningError {
                                err: err.clone(),
@@ -398,13 +398,6 @@ pub(super) enum RAACommitmentOrder {
 // Note this is only exposed in cfg(test):
 pub(super) struct ChannelHolder<Signer: Sign> {
        pub(super) by_id: HashMap<[u8; 32], Channel<Signer>>,
-       /// Map from payment hash to the payment data and any HTLCs which are to us and can be
-       /// failed/claimed by the user.
-       ///
-       /// Note that while this is held in the same mutex as the channels themselves, no consistency
-       /// guarantees are made about the channels given here actually existing anymore by the time you
-       /// go to read them!
-       claimable_htlcs: HashMap<PaymentHash, (events::PaymentPurpose, Vec<ClaimableHTLC>)>,
        /// Messages to send to peers - pushed to in the same lock that they are generated in (except
        /// for broadcast messages, where ordering isn't as strict).
        pub(super) pending_msg_events: Vec<MessageSendEvent>,
@@ -673,19 +666,21 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L> = ChannelManage
 //  |
 //  |__`forward_htlcs`
 //  |
-//  |__`channel_state`
+//  |__`pending_inbound_payments`
 //  |   |
-//  |   |__`id_to_peer`
+//  |   |__`claimable_htlcs`
 //  |   |
-//  |   |__`short_to_chan_info`
-//  |   |
-//  |   |__`per_peer_state`
-//  |       |
-//  |       |__`outbound_scid_aliases`
+//  |   |__`pending_outbound_payments`
 //  |       |
-//  |       |__`pending_inbound_payments`
+//  |       |__`channel_state`
+//  |           |
+//  |           |__`id_to_peer`
 //  |           |
-//  |           |__`pending_outbound_payments`
+//  |           |__`short_to_chan_info`
+//  |           |
+//  |           |__`per_peer_state`
+//  |               |
+//  |               |__`outbound_scid_aliases`
 //  |               |
 //  |               |__`best_block`
 //  |               |
@@ -756,6 +751,15 @@ pub struct ChannelManager<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
        #[cfg(not(test))]
        forward_htlcs: Mutex<HashMap<u64, Vec<HTLCForwardInfo>>>,
 
+       /// Map from payment hash to the payment data and any HTLCs which are to us and can be
+       /// failed/claimed by the user.
+       ///
+       /// Note that, no consistency guarantees are made about the channels given here actually
+       /// existing anymore by the time you go to read them!
+       ///
+       /// See `ChannelManager` struct-level documentation for lock order requirements.
+       claimable_htlcs: Mutex<HashMap<PaymentHash, (events::PaymentPurpose, Vec<ClaimableHTLC>)>>,
+
        /// The set of outbound SCID aliases across all our channels, including unconfirmed channels
        /// and some closed channels which reached a usable state prior to being closed. This is used
        /// only to avoid duplicates, and is not persisted explicitly to disk, but rebuilt from the
@@ -1086,8 +1090,10 @@ pub struct ChannelDetails {
        ///
        /// [`outbound_capacity_msat`]: ChannelDetails::outbound_capacity_msat
        pub unspendable_punishment_reserve: Option<u64>,
-       /// The `user_channel_id` passed in to create_channel, or 0 if the channel was inbound.
-       pub user_channel_id: u64,
+       /// The `user_channel_id` passed in to create_channel, or a random value if the channel was
+       /// inbound. This may be zero for inbound channels serialized with LDK versions prior to
+       /// 0.0.113.
+       pub user_channel_id: u128,
        /// 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.
@@ -1203,24 +1209,40 @@ impl ChannelDetails {
 #[derive(Clone, Debug)]
 pub enum PaymentSendFailure {
        /// A parameter which was passed to send_payment was invalid, preventing us from attempting to
-       /// send the payment at all. No channel state has been changed or messages sent to peers, and
-       /// once you've changed the parameter at error, you can freely retry the payment in full.
+       /// send the payment at all.
+       ///
+       /// You can freely resend the payment in full (with the parameter error fixed).
+       ///
+       /// Because the payment failed outright, no payment tracking is done, you do not need to call
+       /// [`ChannelManager::abandon_payment`] and [`ChannelManager::retry_payment`] will *not* work
+       /// for this payment.
        ParameterError(APIError),
        /// A parameter in a single path which was passed to send_payment was invalid, preventing us
-       /// from attempting to send the payment at all. No channel state has been changed or messages
-       /// sent to peers, and once you've changed the parameter at error, you can freely retry the
-       /// payment in full.
+       /// from attempting to send the payment at all.
+       ///
+       /// You can freely resend the payment in full (with the parameter error fixed).
        ///
        /// The results here are ordered the same as the paths in the route object which was passed to
        /// send_payment.
+       ///
+       /// Because the payment failed outright, no payment tracking is done, you do not need to call
+       /// [`ChannelManager::abandon_payment`] and [`ChannelManager::retry_payment`] will *not* work
+       /// for this payment.
        PathParameterError(Vec<Result<(), APIError>>),
        /// All paths which were attempted failed to send, with no channel state change taking place.
-       /// You can freely retry the payment in full (though you probably want to do so over different
+       /// You can freely resend the payment in full (though you probably want to do so over different
        /// paths than the ones selected).
        ///
-       /// [`ChannelManager::abandon_payment`] does *not* need to be called for this payment and
-       /// [`ChannelManager::retry_payment`] will *not* work for this payment.
-       AllFailedRetrySafe(Vec<APIError>),
+       /// Because the payment failed outright, no payment tracking is done, you do not need to call
+       /// [`ChannelManager::abandon_payment`] and [`ChannelManager::retry_payment`] will *not* work
+       /// for this payment.
+       AllFailedResendSafe(Vec<APIError>),
+       /// Indicates that a payment for the provided [`PaymentId`] is already in-flight and has not
+       /// yet completed (i.e. generated an [`Event::PaymentSent`]) or been abandoned (via
+       /// [`ChannelManager::abandon_payment`]).
+       ///
+       /// [`Event::PaymentSent`]: events::Event::PaymentSent
+       DuplicatePayment,
        /// Some paths which were attempted failed to send, though possibly not all. At least some
        /// paths have irrevocably committed to the HTLC and retrying the payment in full would result
        /// in over-/re-payment.
@@ -1499,134 +1521,6 @@ macro_rules! emit_channel_ready_event {
        }
 }
 
-macro_rules! handle_chan_restoration_locked {
-       ($self: ident, $channel_lock: expr, $channel_state: expr, $channel_entry: expr,
-        $raa: expr, $commitment_update: expr, $order: expr, $chanmon_update: expr,
-        $pending_forwards: expr, $funding_broadcastable: expr, $channel_ready: expr, $announcement_sigs: expr) => { {
-               let mut htlc_forwards = None;
-
-               let chanmon_update: Option<ChannelMonitorUpdate> = $chanmon_update; // Force type-checking to resolve
-               let chanmon_update_is_none = chanmon_update.is_none();
-               let counterparty_node_id = $channel_entry.get().get_counterparty_node_id();
-               let res = loop {
-                       let forwards: Vec<(PendingHTLCInfo, u64)> = $pending_forwards; // Force type-checking to resolve
-                       if !forwards.is_empty() {
-                               htlc_forwards = Some(($channel_entry.get().get_short_channel_id().unwrap_or($channel_entry.get().outbound_scid_alias()),
-                                       $channel_entry.get().get_funding_txo().unwrap(), forwards));
-                       }
-
-                       if chanmon_update.is_some() {
-                               // On reconnect, we, by definition, only resend a channel_ready if there have been
-                               // no commitment updates, so the only channel monitor update which could also be
-                               // associated with a channel_ready would be the funding_created/funding_signed
-                               // monitor update. That monitor update failing implies that we won't send
-                               // channel_ready until it's been updated, so we can't have a channel_ready and a
-                               // monitor update here (so we don't bother to handle it correctly below).
-                               assert!($channel_ready.is_none());
-                               // A channel monitor update makes no sense without either a channel_ready or a
-                               // commitment update to process after it. Since we can't have a channel_ready, we
-                               // only bother to handle the monitor-update + commitment_update case below.
-                               assert!($commitment_update.is_some());
-                       }
-
-                       if let Some(msg) = $channel_ready {
-                               // Similar to the above, this implies that we're letting the channel_ready fly
-                               // before it should be allowed to.
-                               assert!(chanmon_update.is_none());
-                               send_channel_ready!($self, $channel_state.pending_msg_events, $channel_entry.get(), msg);
-                       }
-                       if let Some(msg) = $announcement_sigs {
-                               $channel_state.pending_msg_events.push(events::MessageSendEvent::SendAnnouncementSignatures {
-                                       node_id: counterparty_node_id,
-                                       msg,
-                               });
-                       }
-
-                       emit_channel_ready_event!($self, $channel_entry.get_mut());
-
-                       let funding_broadcastable: Option<Transaction> = $funding_broadcastable; // Force type-checking to resolve
-                       if let Some(monitor_update) = chanmon_update {
-                               // We only ever broadcast a funding transaction in response to a funding_signed
-                               // message and the resulting monitor update. Thus, on channel_reestablish
-                               // message handling we can't have a funding transaction to broadcast. When
-                               // processing a monitor update finishing resulting in a funding broadcast, we
-                               // cannot have a second monitor update, thus this case would indicate a bug.
-                               assert!(funding_broadcastable.is_none());
-                               // Given we were just reconnected or finished updating a channel monitor, the
-                               // only case where we can get a new ChannelMonitorUpdate would be if we also
-                               // have some commitment updates to send as well.
-                               assert!($commitment_update.is_some());
-                               match $self.chain_monitor.update_channel($channel_entry.get().get_funding_txo().unwrap(), monitor_update) {
-                                       ChannelMonitorUpdateStatus::Completed => {},
-                                       e => {
-                                               // channel_reestablish doesn't guarantee the order it returns is sensical
-                                               // for the messages it returns, but if we're setting what messages to
-                                               // re-transmit on monitor update success, we need to make sure it is sane.
-                                               let mut order = $order;
-                                               if $raa.is_none() {
-                                                       order = RAACommitmentOrder::CommitmentFirst;
-                                               }
-                                               break handle_monitor_update_res!($self, e, $channel_entry, order, $raa.is_some(), true);
-                                       }
-                               }
-                       }
-
-                       macro_rules! handle_cs { () => {
-                               if let Some(update) = $commitment_update {
-                                       $channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
-                                               node_id: counterparty_node_id,
-                                               updates: update,
-                                       });
-                               }
-                       } }
-                       macro_rules! handle_raa { () => {
-                               if let Some(revoke_and_ack) = $raa {
-                                       $channel_state.pending_msg_events.push(events::MessageSendEvent::SendRevokeAndACK {
-                                               node_id: counterparty_node_id,
-                                               msg: revoke_and_ack,
-                                       });
-                               }
-                       } }
-                       match $order {
-                               RAACommitmentOrder::CommitmentFirst => {
-                                       handle_cs!();
-                                       handle_raa!();
-                               },
-                               RAACommitmentOrder::RevokeAndACKFirst => {
-                                       handle_raa!();
-                                       handle_cs!();
-                               },
-                       }
-                       if let Some(tx) = funding_broadcastable {
-                               log_info!($self.logger, "Broadcasting funding transaction with txid {}", tx.txid());
-                               $self.tx_broadcaster.broadcast_transaction(&tx);
-                       }
-                       break Ok(());
-               };
-
-               if chanmon_update_is_none {
-                       // If there was no ChannelMonitorUpdate, we should never generate an Err in the res loop
-                       // above. Doing so would imply calling handle_err!() from channel_monitor_updated() which
-                       // should *never* end up calling back to `chain_monitor.update_channel()`.
-                       assert!(res.is_ok());
-               }
-
-               (htlc_forwards, res, counterparty_node_id)
-       } }
-}
-
-macro_rules! post_handle_chan_restoration {
-       ($self: ident, $locked_res: expr) => { {
-               let (htlc_forwards, res, counterparty_node_id) = $locked_res;
-
-               let _ = handle_error!($self, res, counterparty_node_id);
-
-               if let Some(forwards) = htlc_forwards {
-                       $self.forward_htlcs(&mut [forwards][..]);
-               }
-       } }
-}
-
 impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F, L>
        where M::Target: chain::Watch<<K::Target as KeysInterface>::Signer>,
         T::Target: BroadcasterInterface,
@@ -1660,13 +1554,13 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
 
                        channel_state: Mutex::new(ChannelHolder{
                                by_id: HashMap::new(),
-                               claimable_htlcs: HashMap::new(),
                                pending_msg_events: Vec::new(),
                        }),
                        outbound_scid_aliases: Mutex::new(HashSet::new()),
                        pending_inbound_payments: Mutex::new(HashMap::new()),
                        pending_outbound_payments: Mutex::new(HashMap::new()),
                        forward_htlcs: Mutex::new(HashMap::new()),
+                       claimable_htlcs: Mutex::new(HashMap::new()),
                        id_to_peer: Mutex::new(HashMap::new()),
                        short_to_chan_info: FairRwLock::new(HashMap::new()),
 
@@ -1722,10 +1616,9 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        ///
        /// `user_channel_id` will be provided back as in
        /// [`Event::FundingGenerationReady::user_channel_id`] to allow tracking of which events
-       /// correspond with which `create_channel` call. Note that the `user_channel_id` defaults to 0
-       /// for inbound channels, so you may wish to avoid using 0 for `user_channel_id` here.
-       /// `user_channel_id` has no meaning inside of LDK, it is simply copied to events and otherwise
-       /// ignored.
+       /// correspond with which `create_channel` call. Note that the `user_channel_id` defaults to a
+       /// randomized value for inbound channels. `user_channel_id` has no meaning inside of LDK, it
+       /// is simply copied to events and otherwise ignored.
        ///
        /// Raises [`APIError::APIMisuseError`] when `channel_value_satoshis` > 2**24 or `push_msat` is
        /// greater than `channel_value_satoshis * 1k` or `channel_value_satoshis < 1000`.
@@ -1744,7 +1637,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        /// [`Event::FundingGenerationReady::user_channel_id`]: events::Event::FundingGenerationReady::user_channel_id
        /// [`Event::FundingGenerationReady::temporary_channel_id`]: events::Event::FundingGenerationReady::temporary_channel_id
        /// [`Event::ChannelClosed::channel_id`]: events::Event::ChannelClosed::channel_id
-       pub fn create_channel(&self, their_network_key: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_channel_id: u64, override_config: Option<UserConfig>) -> Result<[u8; 32], APIError> {
+       pub fn create_channel(&self, their_network_key: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_channel_id: u128, override_config: Option<UserConfig>) -> Result<[u8; 32], APIError> {
                if channel_value_satoshis < 1000 {
                        return Err(APIError::APIMisuseError { err: format!("Channel value must be at least 1000 satoshis. It was {}", channel_value_satoshis) });
                }
@@ -1905,14 +1798,16 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                        if *counterparty_node_id != chan_entry.get().get_counterparty_node_id(){
                                                return Err(APIError::APIMisuseError { err: "The passed counterparty_node_id doesn't match the channel's counterparty node_id".to_owned() });
                                        }
-                                       let per_peer_state = self.per_peer_state.read().unwrap();
-                                       let (shutdown_msg, monitor_update, htlcs) = match per_peer_state.get(&counterparty_node_id) {
-                                               Some(peer_state) => {
-                                                       let peer_state = peer_state.lock().unwrap();
-                                                       let their_features = &peer_state.latest_features;
-                                                       chan_entry.get_mut().get_shutdown(&self.keys_manager, their_features, target_feerate_sats_per_1000_weight)?
-                                               },
-                                               None => return Err(APIError::ChannelUnavailable { err: format!("Not connected to node: {}", counterparty_node_id) }),
+                                       let (shutdown_msg, monitor_update, htlcs) = {
+                                               let per_peer_state = self.per_peer_state.read().unwrap();
+                                               match per_peer_state.get(&counterparty_node_id) {
+                                                       Some(peer_state) => {
+                                                               let peer_state = peer_state.lock().unwrap();
+                                                               let their_features = &peer_state.latest_features;
+                                                               chan_entry.get_mut().get_shutdown(&self.keys_manager, their_features, target_feerate_sats_per_1000_weight)?
+                                                       },
+                                                       None => return Err(APIError::ChannelUnavailable { err: format!("Not connected to node: {}", counterparty_node_id) }),
+                                               }
                                        };
                                        failed_htlcs = htlcs;
 
@@ -2138,13 +2033,6 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                }
 
                let routing = match hop_data.format {
-                       msgs::OnionHopDataFormat::Legacy { .. } => {
-                               return Err(ReceiveError {
-                                       err_code: 0x4000|0x2000|3,
-                                       err_data: Vec::new(),
-                                       msg: "We require payment_secrets",
-                               });
-                       },
                        msgs::OnionHopDataFormat::NonFinalNode { .. } => {
                                return Err(ReceiveError {
                                        err_code: 0x4000|22,
@@ -2197,8 +2085,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                        routing,
                        payment_hash,
                        incoming_shared_secret: shared_secret,
-                       amt_incoming: Some(amt_msat),
-                       amt_to_forward: amt_msat,
+                       incoming_amt_msat: Some(amt_msat),
+                       outgoing_amt_msat: amt_msat,
                        outgoing_cltv_value: hop_data.outgoing_cltv_value,
                })
        }
@@ -2280,7 +2168,6 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                };
 
                                let short_channel_id = match next_hop_data.format {
-                                       msgs::OnionHopDataFormat::Legacy { short_channel_id } => short_channel_id,
                                        msgs::OnionHopDataFormat::NonFinalNode { short_channel_id } => short_channel_id,
                                        msgs::OnionHopDataFormat::FinalNode { .. } => {
                                                return_err!("Final Node OnionHopData provided for us as an intermediary node", 0x4000 | 22, &[0;0]);
@@ -2294,14 +2181,14 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                        },
                                        payment_hash: msg.payment_hash.clone(),
                                        incoming_shared_secret: shared_secret,
-                                       amt_incoming: Some(msg.amount_msat),
-                                       amt_to_forward: next_hop_data.amt_to_forward,
+                                       incoming_amt_msat: Some(msg.amount_msat),
+                                       outgoing_amt_msat: next_hop_data.amt_to_forward,
                                        outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
                                })
                        }
                };
 
-               if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref routing, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
+               if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref routing, ref outgoing_amt_msat, ref outgoing_cltv_value, .. }) = &pending_forward_info {
                        // If short_channel_id is 0 here, we'll reject the HTLC as there cannot be a channel
                        // with a short_channel_id of 0. This is important as various things later assume
                        // short_channel_id is non-0 in any ::Forward.
@@ -2352,10 +2239,10 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                if !chan.is_live() { // channel_disabled
                                                        break Some(("Forwarding channel is not in a ready state.", 0x1000 | 20, chan_update_opt));
                                                }
-                                               if *amt_to_forward < chan.get_counterparty_htlc_minimum_msat() { // amount_below_minimum
+                                               if *outgoing_amt_msat < chan.get_counterparty_htlc_minimum_msat() { // amount_below_minimum
                                                        break Some(("HTLC amount was below the htlc_minimum_msat", 0x1000 | 11, chan_update_opt));
                                                }
-                                               if let Err((err, code)) = chan.htlc_satisfies_config(&msg, *amt_to_forward, *outgoing_cltv_value) {
+                                               if let Err((err, code)) = chan.htlc_satisfies_config(&msg, *outgoing_amt_msat, *outgoing_cltv_value) {
                                                        break Some((err, code, chan_update_opt));
                                                }
                                                chan_update_opt
@@ -2640,9 +2527,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
 
                let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
                match pending_outbounds.entry(payment_id) {
-                       hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::ParameterError(APIError::RouteError {
-                               err: "Payment already in progress"
-                       })),
+                       hash_map::Entry::Occupied(_) => Err(PaymentSendFailure::DuplicatePayment),
                        hash_map::Entry::Vacant(entry) => {
                                let payment = entry.insert(PendingOutboundPayment::Retryable {
                                        session_privs: HashSet::new(),
@@ -2756,7 +2641,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                        // `pending_outbound_payments` map, as the user isn't expected to `abandon_payment`.
                        let removed = self.pending_outbound_payments.lock().unwrap().remove(&payment_id).is_some();
                        debug_assert!(removed, "We should always have a pending payment to remove here");
-                       Err(PaymentSendFailure::AllFailedRetrySafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
+                       Err(PaymentSendFailure::AllFailedResendSafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
                } else {
                        Ok(())
                }
@@ -3147,8 +3032,6 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                        mem::swap(&mut forward_htlcs, &mut self.forward_htlcs.lock().unwrap());
 
                        for (short_chan_id, mut pending_forwards) in forward_htlcs {
-                               let mut channel_state_lock = self.channel_state.lock().unwrap();
-                               let channel_state = &mut *channel_state_lock;
                                if short_chan_id != 0 {
                                        macro_rules! forwarding_channel_not_found {
                                                () => {
@@ -3157,8 +3040,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                        HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
                                                                                prev_short_channel_id, prev_htlc_id, prev_funding_outpoint,
                                                                                forward_info: PendingHTLCInfo {
-                                                                                       routing, incoming_shared_secret, payment_hash, amt_to_forward,
-                                                                                       outgoing_cltv_value, amt_incoming: _
+                                                                                       routing, incoming_shared_secret, payment_hash, outgoing_amt_msat,
+                                                                                       outgoing_cltv_value, incoming_amt_msat: _
                                                                                }
                                                                        }) => {
                                                                                macro_rules! failure_handler {
@@ -3220,7 +3103,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                                                };
                                                                                                match next_hop {
                                                                                                        onion_utils::Hop::Receive(hop_data) => {
-                                                                                                               match self.construct_recv_pending_htlc_info(hop_data, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value, Some(phantom_shared_secret)) {
+                                                                                                               match self.construct_recv_pending_htlc_info(hop_data, incoming_shared_secret, payment_hash, outgoing_amt_msat, outgoing_cltv_value, Some(phantom_shared_secret)) {
                                                                                                                        Ok(info) => phantom_receives.push((prev_short_channel_id, prev_funding_outpoint, vec![(info, prev_htlc_id)])),
                                                                                                                        Err(ReceiveError { err_code, err_data, msg }) => failed_payment!(msg, err_code, err_data, Some(phantom_shared_secret))
                                                                                                                }
@@ -3251,6 +3134,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                        continue;
                                                }
                                        };
+                                       let mut channel_state_lock = self.channel_state.lock().unwrap();
+                                       let channel_state = &mut *channel_state_lock;
                                        match channel_state.by_id.entry(forward_chan_id) {
                                                hash_map::Entry::Vacant(_) => {
                                                        forwarding_channel_not_found!();
@@ -3264,8 +3149,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                        HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
                                                                                prev_short_channel_id, prev_htlc_id, prev_funding_outpoint ,
                                                                                forward_info: PendingHTLCInfo {
-                                                                                       incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value,
-                                                                                       routing: PendingHTLCRouting::Forward { onion_packet, .. }, amt_incoming: _,
+                                                                                       incoming_shared_secret, payment_hash, outgoing_amt_msat, outgoing_cltv_value,
+                                                                                       routing: PendingHTLCRouting::Forward { onion_packet, .. }, incoming_amt_msat: _,
                                                                                },
                                                                        }) => {
                                                                                log_trace!(self.logger, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", prev_short_channel_id, log_bytes!(payment_hash.0), short_chan_id);
@@ -3277,7 +3162,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                                        // Phantom payments are only PendingHTLCRouting::Receive.
                                                                                        phantom_shared_secret: None,
                                                                                });
-                                                                               match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet, &self.logger) {
+                                                                               match chan.get_mut().send_htlc(outgoing_amt_msat, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet, &self.logger) {
                                                                                        Err(e) => {
                                                                                                if let ChannelError::Ignore(msg) = e {
                                                                                                        log_trace!(self.logger, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg);
@@ -3391,7 +3276,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                        HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
                                                                prev_short_channel_id, prev_htlc_id, prev_funding_outpoint,
                                                                forward_info: PendingHTLCInfo {
-                                                                       routing, incoming_shared_secret, payment_hash, amt_to_forward, ..
+                                                                       routing, incoming_shared_secret, payment_hash, outgoing_amt_msat, ..
                                                                }
                                                        }) => {
                                                                let (cltv_expiry, onion_payload, payment_data, phantom_shared_secret) = match routing {
@@ -3413,9 +3298,9 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                                incoming_packet_shared_secret: incoming_shared_secret,
                                                                                phantom_shared_secret,
                                                                        },
-                                                                       value: amt_to_forward,
+                                                                       value: outgoing_amt_msat,
                                                                        timer_ticks: 0,
-                                                                       total_msat: if let Some(data) = &payment_data { data.total_msat } else { amt_to_forward },
+                                                                       total_msat: if let Some(data) = &payment_data { data.total_msat } else { outgoing_amt_msat },
                                                                        cltv_expiry,
                                                                        onion_payload,
                                                                };
@@ -3448,7 +3333,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                                                payment_secret: $payment_data.payment_secret,
                                                                                        }
                                                                                };
-                                                                               let (_, htlcs) = channel_state.claimable_htlcs.entry(payment_hash)
+                                                                               let mut claimable_htlcs = self.claimable_htlcs.lock().unwrap();
+                                                                               let (_, htlcs) = claimable_htlcs.entry(payment_hash)
                                                                                        .or_insert_with(|| (purpose(), Vec::new()));
                                                                                if htlcs.len() == 1 {
                                                                                        if let OnionPayload::Spontaneous(_) = htlcs[0].onion_payload {
@@ -3516,13 +3402,13 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                                                                check_total_value!(payment_data, payment_preimage);
                                                                                        },
                                                                                        OnionPayload::Spontaneous(preimage) => {
-                                                                                               match channel_state.claimable_htlcs.entry(payment_hash) {
+                                                                                               match self.claimable_htlcs.lock().unwrap().entry(payment_hash) {
                                                                                                        hash_map::Entry::Vacant(e) => {
                                                                                                                let purpose = events::PaymentPurpose::SpontaneousPayment(preimage);
                                                                                                                e.insert((purpose.clone(), vec![claimable_htlc]));
                                                                                                                new_events.push(events::Event::PaymentReceived {
                                                                                                                        payment_hash,
-                                                                                                                       amount_msat: amt_to_forward,
+                                                                                                                       amount_msat: outgoing_amt_msat,
                                                                                                                        purpose,
                                                                                                                });
                                                                                                        },
@@ -3805,29 +3691,29 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
 
                                        true
                                });
+                       }
 
-                               channel_state.claimable_htlcs.retain(|payment_hash, (_, htlcs)| {
-                                       if htlcs.is_empty() {
-                                               // This should be unreachable
-                                               debug_assert!(false);
+                       self.claimable_htlcs.lock().unwrap().retain(|payment_hash, (_, htlcs)| {
+                               if htlcs.is_empty() {
+                                       // This should be unreachable
+                                       debug_assert!(false);
+                                       return false;
+                               }
+                               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) {
+                                               return true;
+                                       } else if htlcs.into_iter().any(|htlc| {
+                                               htlc.timer_ticks += 1;
+                                               return htlc.timer_ticks >= MPP_TIMEOUT_TICKS
+                                       }) {
+                                               timed_out_mpp_htlcs.extend(htlcs.into_iter().map(|htlc| (htlc.prev_hop.clone(), payment_hash.clone())));
                                                return false;
                                        }
-                                       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) {
-                                                       return true;
-                                               } else if htlcs.into_iter().any(|htlc| {
-                                                       htlc.timer_ticks += 1;
-                                                       return htlc.timer_ticks >= MPP_TIMEOUT_TICKS
-                                               }) {
-                                                       timed_out_mpp_htlcs.extend(htlcs.into_iter().map(|htlc| (htlc.prev_hop.clone(), payment_hash.clone())));
-                                                       return false;
-                                               }
-                                       }
-                                       true
-                               });
-                       }
+                               }
+                               true
+                       });
 
                        for htlc_source in timed_out_mpp_htlcs.drain(..) {
                                let receiver = HTLCDestination::FailedPayment { payment_hash: htlc_source.1 };
@@ -3860,10 +3746,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash) {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
-               let removed_source = {
-                       let mut channel_state = self.channel_state.lock().unwrap();
-                       channel_state.claimable_htlcs.remove(payment_hash)
-               };
+               let removed_source = self.claimable_htlcs.lock().unwrap().remove(payment_hash);
                if let Some((_, mut sources)) = removed_source {
                        for htlc in sources.drain(..) {
                                let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
@@ -4165,7 +4048,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
 
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
-               let removed_source = self.channel_state.lock().unwrap().claimable_htlcs.remove(&payment_hash);
+               let removed_source = self.claimable_htlcs.lock().unwrap().remove(&payment_hash);
                if let Some((payment_purpose, mut sources)) = removed_source {
                        assert!(!sources.is_empty());
 
@@ -4483,10 +4366,73 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                self.our_network_pubkey.clone()
        }
 
+       /// Handles a channel reentering a functional state, either due to reconnect or a monitor
+       /// update completion.
+       fn handle_channel_resumption(&self, pending_msg_events: &mut Vec<MessageSendEvent>,
+               channel: &mut Channel<<K::Target as KeysInterface>::Signer>, raa: Option<msgs::RevokeAndACK>,
+               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, Vec<(PendingHTLCInfo, u64)>)> {
+               let mut htlc_forwards = None;
+
+               let counterparty_node_id = channel.get_counterparty_node_id();
+               if !pending_forwards.is_empty() {
+                       htlc_forwards = Some((channel.get_short_channel_id().unwrap_or(channel.outbound_scid_alias()),
+                               channel.get_funding_txo().unwrap(), pending_forwards));
+               }
+
+               if let Some(msg) = channel_ready {
+                       send_channel_ready!(self, pending_msg_events, channel, msg);
+               }
+               if let Some(msg) = announcement_sigs {
+                       pending_msg_events.push(events::MessageSendEvent::SendAnnouncementSignatures {
+                               node_id: counterparty_node_id,
+                               msg,
+                       });
+               }
+
+               emit_channel_ready_event!(self, channel);
+
+               macro_rules! handle_cs { () => {
+                       if let Some(update) = commitment_update {
+                               pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
+                                       node_id: counterparty_node_id,
+                                       updates: update,
+                               });
+                       }
+               } }
+               macro_rules! handle_raa { () => {
+                       if let Some(revoke_and_ack) = raa {
+                               pending_msg_events.push(events::MessageSendEvent::SendRevokeAndACK {
+                                       node_id: counterparty_node_id,
+                                       msg: revoke_and_ack,
+                               });
+                       }
+               } }
+               match order {
+                       RAACommitmentOrder::CommitmentFirst => {
+                               handle_cs!();
+                               handle_raa!();
+                       },
+                       RAACommitmentOrder::RevokeAndACKFirst => {
+                               handle_raa!();
+                               handle_cs!();
+                       },
+               }
+
+               if let Some(tx) = funding_broadcastable {
+                       log_info!(self.logger, "Broadcasting funding transaction with txid {}", tx.txid());
+                       self.tx_broadcaster.broadcast_transaction(&tx);
+               }
+
+               htlc_forwards
+       }
+
        fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64) {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
-               let chan_restoration_res;
+               let htlc_forwards;
                let (mut pending_failures, finalized_claims, counterparty_node_id) = {
                        let mut channel_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_lock;
@@ -4513,14 +4459,16 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                        })
                                } else { None }
                        } else { None };
-                       chan_restoration_res = handle_chan_restoration_locked!(self, channel_lock, channel_state, channel, updates.raa, updates.commitment_update, updates.order, None, updates.accepted_htlcs, updates.funding_broadcastable, updates.channel_ready, updates.announcement_sigs);
+                       htlc_forwards = self.handle_channel_resumption(&mut channel_state.pending_msg_events, channel.get_mut(), updates.raa, updates.commitment_update, updates.order, updates.accepted_htlcs, updates.funding_broadcastable, updates.channel_ready, updates.announcement_sigs);
                        if let Some(upd) = channel_update {
                                channel_state.pending_msg_events.push(upd);
                        }
 
                        (updates.failed_htlcs, updates.finalized_claimed_htlcs, counterparty_node_id)
                };
-               post_handle_chan_restoration!(self, chan_restoration_res);
+               if let Some(forwards) = htlc_forwards {
+                       self.forward_htlcs(&mut [forwards][..]);
+               }
                self.finalize_claims(finalized_claims);
                for failure in pending_failures.drain(..) {
                        let receiver = HTLCDestination::NextHopChannel { node_id: Some(counterparty_node_id), channel_id: funding_txo.to_channel_id() };
@@ -4544,7 +4492,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        ///
        /// [`Event::OpenChannelRequest`]: events::Event::OpenChannelRequest
        /// [`Event::ChannelClosed::user_channel_id`]: events::Event::ChannelClosed::user_channel_id
-       pub fn accept_inbound_channel(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, user_channel_id: u64) -> Result<(), APIError> {
+       pub fn accept_inbound_channel(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, user_channel_id: u128) -> Result<(), APIError> {
                self.do_accept_inbound_channel(temporary_channel_id, counterparty_node_id, false, user_channel_id)
        }
 
@@ -4566,11 +4514,11 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        ///
        /// [`Event::OpenChannelRequest`]: events::Event::OpenChannelRequest
        /// [`Event::ChannelClosed::user_channel_id`]: events::Event::ChannelClosed::user_channel_id
-       pub fn accept_inbound_channel_from_trusted_peer_0conf(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, user_channel_id: u64) -> Result<(), APIError> {
+       pub fn accept_inbound_channel_from_trusted_peer_0conf(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, user_channel_id: u128) -> Result<(), APIError> {
                self.do_accept_inbound_channel(temporary_channel_id, counterparty_node_id, true, user_channel_id)
        }
 
-       fn do_accept_inbound_channel(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, accept_0conf: bool, user_channel_id: u64) -> Result<(), APIError> {
+       fn do_accept_inbound_channel(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, accept_0conf: bool, user_channel_id: u128) -> Result<(), APIError> {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
                let mut channel_state_lock = self.channel_state.lock().unwrap();
@@ -4618,9 +4566,13 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                        return Err(MsgHandleErrInternal::send_err_msg_no_close("No inbound channels accepted".to_owned(), msg.temporary_channel_id.clone()));
                }
 
+               let mut random_bytes = [0u8; 16];
+               random_bytes.copy_from_slice(&self.keys_manager.get_secure_random_bytes()[..16]);
+               let user_channel_id = u128::from_be_bytes(random_bytes);
+
                let outbound_scid_alias = self.create_and_insert_outbound_scid_alias();
                let mut channel = match Channel::new_from_req(&self.fee_estimator, &self.keys_manager,
-                       counterparty_node_id.clone(), &their_features, msg, 0, &self.default_configuration,
+                       counterparty_node_id.clone(), &their_features, msg, user_channel_id, &self.default_configuration,
                        self.best_block.read().unwrap().height(), &self.logger, outbound_scid_alias)
                {
                        Err(e) => {
@@ -4643,7 +4595,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                        }
                                        channel_state.pending_msg_events.push(events::MessageSendEvent::SendAcceptChannel {
                                                node_id: counterparty_node_id.clone(),
-                                               msg: channel.accept_inbound_channel(0),
+                                               msg: channel.accept_inbound_channel(user_channel_id),
                                        });
                                } else {
                                        let mut pending_events = self.pending_events.lock().unwrap();
@@ -5197,7 +5149,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                if chan.get().get_counterparty_node_id() != *counterparty_node_id {
                                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
                                }
-                               try_chan_entry!(self, chan.get_mut().update_fee(&self.fee_estimator, &msg), chan);
+                               try_chan_entry!(self, chan.get_mut().update_fee(&self.fee_estimator, &msg, &self.logger), chan);
                        },
                        hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                }
@@ -5267,8 +5219,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        }
 
        fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
-               let chan_restoration_res;
-               let (htlcs_failed_forward, need_lnd_workaround) = {
+               let htlc_forwards;
+               let need_lnd_workaround = {
                        let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_state_lock;
 
@@ -5302,19 +5254,21 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                                                }
                                        }
                                        let need_lnd_workaround = chan.get_mut().workaround_lnd_bug_4006.take();
-                                       chan_restoration_res = handle_chan_restoration_locked!(
-                                               self, channel_state_lock, channel_state, chan, responses.raa, responses.commitment_update, responses.order,
-                                               responses.mon_update, Vec::new(), None, responses.channel_ready, responses.announcement_sigs);
+                                       htlc_forwards = self.handle_channel_resumption(
+                                               &mut channel_state.pending_msg_events, chan.get_mut(), responses.raa, responses.commitment_update, responses.order,
+                                               Vec::new(), None, responses.channel_ready, responses.announcement_sigs);
                                        if let Some(upd) = channel_update {
                                                channel_state.pending_msg_events.push(upd);
                                        }
-                                       (responses.holding_cell_failed_htlcs, need_lnd_workaround)
+                                       need_lnd_workaround
                                },
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                        }
                };
-               post_handle_chan_restoration!(self, chan_restoration_res);
-               self.fail_holding_cell_htlcs(htlcs_failed_forward, msg.channel_id, counterparty_node_id);
+
+               if let Some(forwards) = htlc_forwards {
+                       self.forward_htlcs(&mut [forwards][..]);
+               }
 
                if let Some(channel_ready_msg) = need_lnd_workaround {
                        self.internal_channel_ready(counterparty_node_id, &channel_ready_msg)?;
@@ -5711,10 +5665,26 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                }
        }
 
+       /// Gets inflight HTLC information by processing pending outbound payments that are in
+       /// our channels. May be used during pathfinding to account for in-use channel liquidity.
+       pub fn compute_inflight_htlcs(&self) -> InFlightHtlcs {
+               let mut inflight_htlcs = InFlightHtlcs::new();
+
+               for chan in self.channel_state.lock().unwrap().by_id.values() {
+                       for htlc_source in chan.inflight_htlc_sources() {
+                               if let HTLCSource::OutboundRoute { path, .. } = htlc_source {
+                                       inflight_htlcs.process_path(path, self.get_our_node_id());
+                               }
+                       }
+               }
+
+               inflight_htlcs
+       }
+
        #[cfg(any(test, fuzzing, feature = "_test_utils"))]
        pub fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
                let events = core::cell::RefCell::new(Vec::new());
-               let event_handler = |event: &events::Event| events.borrow_mut().push(event.clone());
+               let event_handler = |event: events::Event| events.borrow_mut().push(event);
                self.process_pending_events(&event_handler);
                events.into_inner()
        }
@@ -5728,6 +5698,39 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        pub fn clear_pending_payments(&self) {
                self.pending_outbound_payments.lock().unwrap().clear()
        }
+
+       /// Processes any events asynchronously in the order they were generated since the last call
+       /// using the given event handler.
+       ///
+       /// See the trait-level documentation of [`EventsProvider`] for requirements.
+       pub async fn process_pending_events_async<Future: core::future::Future, H: Fn(Event) -> Future>(
+               &self, handler: H
+       ) {
+               // We'll acquire our total consistency lock until the returned future completes so that
+               // we can be sure no other persists happen while processing events.
+               let _read_guard = self.total_consistency_lock.read().unwrap();
+
+               let mut result = NotifyOption::SkipPersist;
+
+               // TODO: This behavior should be documented. It's unintuitive that we query
+               // ChannelMonitors when clearing other events.
+               if self.process_pending_monitor_events() {
+                       result = NotifyOption::DoPersist;
+               }
+
+               let pending_events = mem::replace(&mut *self.pending_events.lock().unwrap(), vec![]);
+               if !pending_events.is_empty() {
+                       result = NotifyOption::DoPersist;
+               }
+
+               for event in pending_events {
+                       handler(event).await;
+               }
+
+               if result == NotifyOption::DoPersist {
+                       self.persistence_notifier.notify();
+               }
+       }
 }
 
 impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> MessageSendEventsProvider for ChannelManager<M, T, K, F, L>
@@ -5791,13 +5794,13 @@ where
                                result = NotifyOption::DoPersist;
                        }
 
-                       let mut pending_events = mem::replace(&mut *self.pending_events.lock().unwrap(), vec![]);
+                       let pending_events = mem::replace(&mut *self.pending_events.lock().unwrap(), vec![]);
                        if !pending_events.is_empty() {
                                result = NotifyOption::DoPersist;
                        }
 
-                       for event in pending_events.drain(..) {
-                               handler.handle_event(&event);
+                       for event in pending_events {
+                               handler.handle_event(event);
                        }
 
                        result
@@ -5906,12 +5909,12 @@ where
                });
        }
 
-       fn get_relevant_txids(&self) -> Vec<Txid> {
+       fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
                let channel_state = self.channel_state.lock().unwrap();
                let mut res = Vec::with_capacity(channel_state.by_id.len());
                for chan in channel_state.by_id.values() {
-                       if let Some(funding_txo) = chan.get_funding_txo() {
-                               res.push(funding_txo.txid);
+                       if let (Some(funding_txo), block_hash) = (chan.get_funding_txo(), chan.get_funding_tx_confirmed_in()) {
+                               res.push((funding_txo.txid, block_hash));
                        }
                }
                res
@@ -6033,28 +6036,28 @@ where
                                }
                                true
                        });
+               }
 
-                       if let Some(height) = height_opt {
-                               channel_state.claimable_htlcs.retain(|payment_hash, (_, htlcs)| {
-                                       htlcs.retain(|htlc| {
-                                               // If height is approaching the number of blocks we think it takes us to get
-                                               // our commitment transaction confirmed before the HTLC expires, plus the
-                                               // number of blocks we generally consider it to take to do a commitment update,
-                                               // just give up on it and fail the HTLC.
-                                               if height >= htlc.cltv_expiry - HTLC_FAIL_BACK_BUFFER {
-                                                       let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
-                                                       htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(height));
-
-                                                       timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), HTLCFailReason::Reason {
-                                                               failure_code: 0x4000 | 15,
-                                                               data: htlc_msat_height_data
-                                                       }, HTLCDestination::FailedPayment { payment_hash: payment_hash.clone() }));
-                                                       false
-                                               } else { true }
-                                       });
-                                       !htlcs.is_empty() // Only retain this entry if htlcs has at least one entry.
+               if let Some(height) = height_opt {
+                       self.claimable_htlcs.lock().unwrap().retain(|payment_hash, (_, htlcs)| {
+                               htlcs.retain(|htlc| {
+                                       // If height is approaching the number of blocks we think it takes us to get
+                                       // our commitment transaction confirmed before the HTLC expires, plus the
+                                       // number of blocks we generally consider it to take to do a commitment update,
+                                       // just give up on it and fail the HTLC.
+                                       if height >= htlc.cltv_expiry - HTLC_FAIL_BACK_BUFFER {
+                                               let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
+                                               htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(height));
+
+                                               timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), HTLCFailReason::Reason {
+                                                       failure_code: 0x4000 | 15,
+                                                       data: htlc_msat_height_data
+                                               }, HTLCDestination::FailedPayment { payment_hash: payment_hash.clone() }));
+                                               false
+                                       } else { true }
                                });
-                       }
+                               !htlcs.is_empty() // Only retain this entry if htlcs has at least one entry.
+                       });
                }
 
                self.handle_init_event_channel_failures(failed_channels);
@@ -6066,18 +6069,25 @@ where
 
        /// Blocks until ChannelManager needs to be persisted or a timeout is reached. It returns a bool
        /// indicating whether persistence is necessary. Only one listener on
-       /// `await_persistable_update` or `await_persistable_update_timeout` is guaranteed to be woken
-       /// up.
+       /// [`await_persistable_update`], [`await_persistable_update_timeout`], or a future returned by
+       /// [`get_persistable_update_future`] is guaranteed to be woken up.
        ///
        /// Note that this method is not available with the `no-std` feature.
+       ///
+       /// [`await_persistable_update`]: Self::await_persistable_update
+       /// [`await_persistable_update_timeout`]: Self::await_persistable_update_timeout
+       /// [`get_persistable_update_future`]: Self::get_persistable_update_future
        #[cfg(any(test, feature = "std"))]
        pub fn await_persistable_update_timeout(&self, max_wait: Duration) -> bool {
                self.persistence_notifier.wait_timeout(max_wait)
        }
 
        /// Blocks until ChannelManager needs to be persisted. Only one listener on
-       /// `await_persistable_update` or `await_persistable_update_timeout` is guaranteed to be woken
-       /// up.
+       /// [`await_persistable_update`], `await_persistable_update_timeout`, or a future returned by
+       /// [`get_persistable_update_future`] is guaranteed to be woken up.
+       ///
+       /// [`await_persistable_update`]: Self::await_persistable_update
+       /// [`get_persistable_update_future`]: Self::get_persistable_update_future
        pub fn await_persistable_update(&self) {
                self.persistence_notifier.wait()
        }
@@ -6418,33 +6428,108 @@ impl_writeable_tlv_based!(ChannelCounterparty, {
        (11, outbound_htlc_maximum_msat, option),
 });
 
-impl_writeable_tlv_based!(ChannelDetails, {
-       (1, inbound_scid_alias, option),
-       (2, channel_id, required),
-       (3, channel_type, option),
-       (4, counterparty, required),
-       (5, outbound_scid_alias, option),
-       (6, funding_txo, option),
-       (7, config, option),
-       (8, short_channel_id, option),
-       (10, channel_value_satoshis, required),
-       (12, unspendable_punishment_reserve, option),
-       (14, user_channel_id, required),
-       (16, balance_msat, required),
-       (18, outbound_capacity_msat, required),
-       // Note that by the time we get past the required read above, outbound_capacity_msat will be
-       // filled in, so we can safely unwrap it here.
-       (19, next_outbound_htlc_limit_msat, (default_value, outbound_capacity_msat.0.unwrap() as u64)),
-       (20, inbound_capacity_msat, required),
-       (22, confirmations_required, option),
-       (24, force_close_spend_delay, option),
-       (26, is_outbound, required),
-       (28, is_channel_ready, required),
-       (30, is_usable, required),
-       (32, is_public, required),
-       (33, inbound_htlc_minimum_msat, option),
-       (35, inbound_htlc_maximum_msat, option),
-});
+impl Writeable for ChannelDetails {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+               // `user_channel_id` used to be a single u64 value. In order to remain backwards compatible with
+               // versions prior to 0.0.113, the u128 is serialized as two separate u64 values.
+               let user_channel_id_low = self.user_channel_id as u64;
+               let user_channel_id_high_opt = Some((self.user_channel_id >> 64) as u64);
+               write_tlv_fields!(writer, {
+                       (1, self.inbound_scid_alias, option),
+                       (2, self.channel_id, required),
+                       (3, self.channel_type, option),
+                       (4, self.counterparty, required),
+                       (5, self.outbound_scid_alias, option),
+                       (6, self.funding_txo, option),
+                       (7, self.config, option),
+                       (8, self.short_channel_id, option),
+                       (10, self.channel_value_satoshis, required),
+                       (12, self.unspendable_punishment_reserve, option),
+                       (14, user_channel_id_low, required),
+                       (16, self.balance_msat, required),
+                       (18, self.outbound_capacity_msat, required),
+                       // Note that by the time we get past the required read above, outbound_capacity_msat will be
+                       // filled in, so we can safely unwrap it here.
+                       (19, self.next_outbound_htlc_limit_msat, (default_value, outbound_capacity_msat.0.unwrap() as u64)),
+                       (20, self.inbound_capacity_msat, required),
+                       (22, self.confirmations_required, option),
+                       (24, self.force_close_spend_delay, option),
+                       (26, self.is_outbound, required),
+                       (28, self.is_channel_ready, required),
+                       (30, self.is_usable, required),
+                       (32, self.is_public, required),
+                       (33, self.inbound_htlc_minimum_msat, option),
+                       (35, self.inbound_htlc_maximum_msat, option),
+                       (37, user_channel_id_high_opt, option),
+               });
+               Ok(())
+       }
+}
+
+impl Readable for ChannelDetails {
+       fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
+               init_and_read_tlv_fields!(reader, {
+                       (1, inbound_scid_alias, option),
+                       (2, channel_id, required),
+                       (3, channel_type, option),
+                       (4, counterparty, required),
+                       (5, outbound_scid_alias, option),
+                       (6, funding_txo, option),
+                       (7, config, option),
+                       (8, short_channel_id, option),
+                       (10, channel_value_satoshis, required),
+                       (12, unspendable_punishment_reserve, option),
+                       (14, user_channel_id_low, required),
+                       (16, balance_msat, required),
+                       (18, outbound_capacity_msat, required),
+                       // Note that by the time we get past the required read above, outbound_capacity_msat will be
+                       // filled in, so we can safely unwrap it here.
+                       (19, next_outbound_htlc_limit_msat, (default_value, outbound_capacity_msat.0.unwrap() as u64)),
+                       (20, inbound_capacity_msat, required),
+                       (22, confirmations_required, option),
+                       (24, force_close_spend_delay, option),
+                       (26, is_outbound, required),
+                       (28, is_channel_ready, required),
+                       (30, is_usable, required),
+                       (32, is_public, required),
+                       (33, inbound_htlc_minimum_msat, option),
+                       (35, inbound_htlc_maximum_msat, option),
+                       (37, user_channel_id_high_opt, option),
+               });
+
+               // `user_channel_id` used to be a single u64 value. In order to remain backwards compatible with
+               // versions prior to 0.0.113, the u128 is serialized as two separate u64 values.
+               let user_channel_id_low: u64 = user_channel_id_low.0.unwrap();
+               let user_channel_id = user_channel_id_low as u128 +
+                       ((user_channel_id_high_opt.unwrap_or(0 as u64) as u128) << 64);
+
+               Ok(Self {
+                       inbound_scid_alias,
+                       channel_id: channel_id.0.unwrap(),
+                       channel_type,
+                       counterparty: counterparty.0.unwrap(),
+                       outbound_scid_alias,
+                       funding_txo,
+                       config,
+                       short_channel_id,
+                       channel_value_satoshis: channel_value_satoshis.0.unwrap(),
+                       unspendable_punishment_reserve,
+                       user_channel_id,
+                       balance_msat: balance_msat.0.unwrap(),
+                       outbound_capacity_msat: outbound_capacity_msat.0.unwrap(),
+                       next_outbound_htlc_limit_msat: next_outbound_htlc_limit_msat.0.unwrap(),
+                       inbound_capacity_msat: inbound_capacity_msat.0.unwrap(),
+                       confirmations_required,
+                       force_close_spend_delay,
+                       is_outbound: is_outbound.0.unwrap(),
+                       is_channel_ready: is_channel_ready.0.unwrap(),
+                       is_usable: is_usable.0.unwrap(),
+                       is_public: is_public.0.unwrap(),
+                       inbound_htlc_minimum_msat,
+                       inbound_htlc_maximum_msat,
+               })
+       }
+}
 
 impl_writeable_tlv_based!(PhantomRouteHints, {
        (2, channels, vec_type),
@@ -6472,9 +6557,9 @@ impl_writeable_tlv_based!(PendingHTLCInfo, {
        (0, routing, required),
        (2, incoming_shared_secret, required),
        (4, payment_hash, required),
-       (6, amt_to_forward, required),
+       (6, outgoing_amt_msat, required),
        (8, outgoing_cltv_value, required),
-       (9, amt_incoming, option),
+       (9, incoming_amt_msat, option),
 });
 
 
@@ -6673,7 +6758,7 @@ impl Writeable for HTLCSource {
                                        (1, payment_id_opt, option),
                                        (2, first_hop_htlc_msat, required),
                                        (3, payment_secret, option),
-                                       (4, path, vec_type),
+                                       (4, *path, vec_type),
                                        (5, payment_params, option),
                                 });
                        }
@@ -6792,10 +6877,13 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelMana
                        }
                }
 
-               let channel_state = self.channel_state.lock().unwrap();
+               let pending_inbound_payments = self.pending_inbound_payments.lock().unwrap();
+               let claimable_htlcs = self.claimable_htlcs.lock().unwrap();
+               let pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
+
                let mut htlc_purposes: Vec<&events::PaymentPurpose> = Vec::new();
-               (channel_state.claimable_htlcs.len() as u64).write(writer)?;
-               for (payment_hash, (purpose, previous_hops)) in channel_state.claimable_htlcs.iter() {
+               (claimable_htlcs.len() as u64).write(writer)?;
+               for (payment_hash, (purpose, previous_hops)) in claimable_htlcs.iter() {
                        payment_hash.write(writer)?;
                        (previous_hops.len() as u64).write(writer)?;
                        for htlc in previous_hops.iter() {
@@ -6812,8 +6900,6 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelMana
                        peer_state.latest_features.write(writer)?;
                }
 
-               let pending_inbound_payments = self.pending_inbound_payments.lock().unwrap();
-               let pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
                let events = self.pending_events.lock().unwrap();
                (events.len() as u64).write(writer)?;
                for event in events.iter() {
@@ -6921,10 +7007,10 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelMana
 /// which you've already broadcasted the transaction.
 ///
 /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
-pub struct ChannelManagerReadArgs<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
-       where M::Target: chain::Watch<Signer>,
+pub struct ChannelManagerReadArgs<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
+       where M::Target: chain::Watch<<K::Target as KeysInterface>::Signer>,
         T::Target: BroadcasterInterface,
-        K::Target: KeysInterface<Signer = Signer>,
+        K::Target: KeysInterface,
         F::Target: FeeEstimator,
         L::Target: Logger,
 {
@@ -6967,14 +7053,14 @@ pub struct ChannelManagerReadArgs<'a, Signer: 'a + Sign, M: Deref, T: Deref, K:
        /// this struct.
        ///
        /// (C-not exported) because we have no HashMap bindings
-       pub channel_monitors: HashMap<OutPoint, &'a mut ChannelMonitor<Signer>>,
+       pub channel_monitors: HashMap<OutPoint, &'a mut ChannelMonitor<<K::Target as KeysInterface>::Signer>>,
 }
 
-impl<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
-               ChannelManagerReadArgs<'a, Signer, M, T, K, F, L>
-       where M::Target: chain::Watch<Signer>,
+impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
+               ChannelManagerReadArgs<'a, M, T, K, F, L>
+       where M::Target: chain::Watch<<K::Target as KeysInterface>::Signer>,
                T::Target: BroadcasterInterface,
-               K::Target: KeysInterface<Signer = Signer>,
+               K::Target: KeysInterface,
                F::Target: FeeEstimator,
                L::Target: Logger,
        {
@@ -6982,7 +7068,7 @@ impl<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
        /// HashMap for you. This is primarily useful for C bindings where it is not practical to
        /// populate a HashMap directly from C.
        pub fn new(keys_manager: K, fee_estimator: F, chain_monitor: M, tx_broadcaster: T, logger: L, default_config: UserConfig,
-                       mut channel_monitors: Vec<&'a mut ChannelMonitor<Signer>>) -> Self {
+                       mut channel_monitors: Vec<&'a mut ChannelMonitor<<K::Target as KeysInterface>::Signer>>) -> Self {
                Self {
                        keys_manager, fee_estimator, chain_monitor, tx_broadcaster, logger, default_config,
                        channel_monitors: channel_monitors.drain(..).map(|monitor| { (monitor.get_funding_txo().0, monitor) }).collect()
@@ -6993,28 +7079,28 @@ impl<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
 // Implement ReadableArgs for an Arc'd ChannelManager to make it a bit easier to work with the
 // SipmleArcChannelManager type:
 impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
-       ReadableArgs<ChannelManagerReadArgs<'a, <K::Target as KeysInterface>::Signer, M, T, K, F, L>> for (BlockHash, Arc<ChannelManager<M, T, K, F, L>>)
+       ReadableArgs<ChannelManagerReadArgs<'a, M, T, K, F, L>> for (BlockHash, Arc<ChannelManager<M, T, K, F, L>>)
        where M::Target: chain::Watch<<K::Target as KeysInterface>::Signer>,
         T::Target: BroadcasterInterface,
         K::Target: KeysInterface,
         F::Target: FeeEstimator,
         L::Target: Logger,
 {
-       fn read<R: io::Read>(reader: &mut R, args: ChannelManagerReadArgs<'a, <K::Target as KeysInterface>::Signer, M, T, K, F, L>) -> Result<Self, DecodeError> {
+       fn read<R: io::Read>(reader: &mut R, args: ChannelManagerReadArgs<'a, M, T, K, F, L>) -> Result<Self, DecodeError> {
                let (blockhash, chan_manager) = <(BlockHash, ChannelManager<M, T, K, F, L>)>::read(reader, args)?;
                Ok((blockhash, Arc::new(chan_manager)))
        }
 }
 
 impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
-       ReadableArgs<ChannelManagerReadArgs<'a, <K::Target as KeysInterface>::Signer, M, T, K, F, L>> for (BlockHash, ChannelManager<M, T, K, F, L>)
+       ReadableArgs<ChannelManagerReadArgs<'a, M, T, K, F, L>> for (BlockHash, ChannelManager<M, T, K, F, L>)
        where M::Target: chain::Watch<<K::Target as KeysInterface>::Signer>,
         T::Target: BroadcasterInterface,
         K::Target: KeysInterface,
         F::Target: FeeEstimator,
         L::Target: Logger,
 {
-       fn read<R: io::Read>(reader: &mut R, mut args: ChannelManagerReadArgs<'a, <K::Target as KeysInterface>::Signer, M, T, K, F, L>) -> Result<Self, DecodeError> {
+       fn read<R: io::Read>(reader: &mut R, mut args: ChannelManagerReadArgs<'a, M, T, K, F, L>) -> Result<Self, DecodeError> {
                let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 
                let genesis_hash: BlockHash = Readable::read(reader)?;
@@ -7406,7 +7492,6 @@ impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
 
                        channel_state: Mutex::new(ChannelHolder {
                                by_id,
-                               claimable_htlcs,
                                pending_msg_events: Vec::new(),
                        }),
                        inbound_payment_key: expanded_inbound_key,
@@ -7414,6 +7499,7 @@ impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                        pending_outbound_payments: Mutex::new(pending_outbound_payments.unwrap()),
 
                        forward_htlcs: Mutex::new(forward_htlcs),
+                       claimable_htlcs: Mutex::new(claimable_htlcs),
                        outbound_scid_aliases: Mutex::new(outbound_scid_aliases),
                        id_to_peer: Mutex::new(id_to_peer),
                        short_to_chan_info: FairRwLock::new(short_to_chan_info),