Merge pull request #2584 from TheBlueMatt/2023-09-msrv-try-2
[rust-lightning] / lightning / src / ln / channelmanager.rs
index eeeab90a8a7334b6cefb7ef8df57a5f245615d4c..0cadbd41a29d21ccb99de1e0d7bf84319e33971c 100644 (file)
@@ -77,7 +77,7 @@ use core::time::Duration;
 use core::ops::Deref;
 
 // Re-export this for use in the public API.
-pub use crate::ln::outbound_payment::{PaymentSendFailure, Retry, RetryableSendFailure, RecipientOnionFields};
+pub use crate::ln::outbound_payment::{PaymentSendFailure, ProbeSendFailure, Retry, RetryableSendFailure, RecipientOnionFields};
 use crate::ln::script::ShutdownScript;
 
 // We hold various information about HTLC relay in the HTLC objects in Channel itself:
@@ -177,7 +177,7 @@ pub(super) enum HTLCForwardInfo {
 }
 
 /// Tracks the inbound corresponding to an outbound HTLC
-#[derive(Clone, Hash, PartialEq, Eq)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub(crate) struct HTLCPreviousHopData {
        // Note that this may be an outbound SCID alias for the associated channel.
        short_channel_id: u64,
@@ -233,7 +233,8 @@ impl From<&ClaimableHTLC> for events::ClaimedHTLC {
        }
 }
 
-/// A payment identifier used to uniquely identify a payment to LDK.
+/// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+/// a payment and ensure idempotency in LDK.
 ///
 /// This is not exported to bindings users as we just use [u8; 32] directly
 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
@@ -282,7 +283,7 @@ impl Readable for InterceptId {
        }
 }
 
-#[derive(Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 /// Uniquely describes an HTLC by its source. Just the guaranteed-unique subset of [`HTLCSource`].
 pub(crate) enum SentHTLCId {
        PreviousHopData { short_channel_id: u64, htlc_id: u64 },
@@ -313,7 +314,7 @@ impl_writeable_tlv_based_enum!(SentHTLCId,
 
 /// Tracks the inbound corresponding to an outbound HTLC
 #[allow(clippy::derive_hash_xor_eq)] // Our Hash is faithful to the data, we just don't have SecretKey::hash
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum HTLCSource {
        PreviousHopData(HTLCPreviousHopData),
        OutboundRoute {
@@ -659,7 +660,6 @@ pub(crate) enum RAAMonitorUpdateBlockingAction {
 }
 
 impl RAAMonitorUpdateBlockingAction {
-       #[allow(unused)]
        fn from_prev_hop_data(prev_hop: &HTLCPreviousHopData) -> Self {
                Self::ForwardedPaymentInboundClaim {
                        channel_id: prev_hop.outpoint.to_channel_id(),
@@ -839,33 +839,46 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> =
                &'g L
        >;
 
-macro_rules! define_test_pub_trait { ($vis: vis) => {
-/// A trivial trait which describes any [`ChannelManager`] used in testing.
-$vis trait AChannelManager {
+/// A trivial trait which describes any [`ChannelManager`].
+pub trait AChannelManager {
+       /// A type implementing [`chain::Watch`].
        type Watch: chain::Watch<Self::Signer> + ?Sized;
+       /// A type that may be dereferenced to [`Self::Watch`].
        type M: Deref<Target = Self::Watch>;
+       /// A type implementing [`BroadcasterInterface`].
        type Broadcaster: BroadcasterInterface + ?Sized;
+       /// A type that may be dereferenced to [`Self::Broadcaster`].
        type T: Deref<Target = Self::Broadcaster>;
+       /// A type implementing [`EntropySource`].
        type EntropySource: EntropySource + ?Sized;
+       /// A type that may be dereferenced to [`Self::EntropySource`].
        type ES: Deref<Target = Self::EntropySource>;
+       /// A type implementing [`NodeSigner`].
        type NodeSigner: NodeSigner + ?Sized;
+       /// A type that may be dereferenced to [`Self::NodeSigner`].
        type NS: Deref<Target = Self::NodeSigner>;
+       /// A type implementing [`WriteableEcdsaChannelSigner`].
        type Signer: WriteableEcdsaChannelSigner + Sized;
+       /// A type implementing [`SignerProvider`] for [`Self::Signer`].
        type SignerProvider: SignerProvider<Signer = Self::Signer> + ?Sized;
+       /// A type that may be dereferenced to [`Self::SignerProvider`].
        type SP: Deref<Target = Self::SignerProvider>;
+       /// A type implementing [`FeeEstimator`].
        type FeeEstimator: FeeEstimator + ?Sized;
+       /// A type that may be dereferenced to [`Self::FeeEstimator`].
        type F: Deref<Target = Self::FeeEstimator>;
+       /// A type implementing [`Router`].
        type Router: Router + ?Sized;
+       /// A type that may be dereferenced to [`Self::Router`].
        type R: Deref<Target = Self::Router>;
+       /// A type implementing [`Logger`].
        type Logger: Logger + ?Sized;
+       /// A type that may be dereferenced to [`Self::Logger`].
        type L: Deref<Target = Self::Logger>;
+       /// Returns a reference to the actual [`ChannelManager`] object.
        fn get_cm(&self) -> &ChannelManager<Self::M, Self::T, Self::ES, Self::NS, Self::SP, Self::F, Self::R, Self::L>;
 }
-} }
-#[cfg(any(test, feature = "_test_utils"))]
-define_test_pub_trait!(pub);
-#[cfg(not(any(test, feature = "_test_utils")))]
-define_test_pub_trait!(pub(crate));
+
 impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> AChannelManager
 for ChannelManager<M, T, ES, NS, SP, F, R, L>
 where
@@ -1233,7 +1246,7 @@ enum NotifyOption {
 /// We allow callers to either always notify by constructing with `notify_on_drop` or choose to
 /// notify or not based on whether relevant changes have been made, providing a closure to
 /// `optionally_notify` which returns a `NotifyOption`.
-struct PersistenceNotifierGuard<'a, F: Fn() -> NotifyOption> {
+struct PersistenceNotifierGuard<'a, F: FnMut() -> NotifyOption> {
        event_persist_notifier: &'a Notifier,
        needs_persist_flag: &'a AtomicBool,
        should_persist: F,
@@ -1248,12 +1261,12 @@ impl<'a> PersistenceNotifierGuard<'a, fn() -> NotifyOption> { // We don't care w
        /// This must always be called if the changes included a `ChannelMonitorUpdate`, as well as in
        /// other cases where losing the changes on restart may result in a force-close or otherwise
        /// isn't ideal.
-       fn notify_on_drop<C: AChannelManager>(cm: &'a C) -> PersistenceNotifierGuard<'a, impl Fn() -> NotifyOption> {
+       fn notify_on_drop<C: AChannelManager>(cm: &'a C) -> PersistenceNotifierGuard<'a, impl FnMut() -> NotifyOption> {
                Self::optionally_notify(cm, || -> NotifyOption { NotifyOption::DoPersist })
        }
 
-       fn optionally_notify<F: Fn() -> NotifyOption, C: AChannelManager>(cm: &'a C, persist_check: F)
-       -> PersistenceNotifierGuard<'a, impl Fn() -> NotifyOption> {
+       fn optionally_notify<F: FnMut() -> NotifyOption, C: AChannelManager>(cm: &'a C, mut persist_check: F)
+       -> PersistenceNotifierGuard<'a, impl FnMut() -> NotifyOption> {
                let read_guard = cm.get_cm().total_consistency_lock.read().unwrap();
                let force_notify = cm.get_cm().process_background_events();
 
@@ -1292,7 +1305,7 @@ impl<'a> PersistenceNotifierGuard<'a, fn() -> NotifyOption> { // We don't care w
        }
 }
 
-impl<'a, F: Fn() -> NotifyOption> Drop for PersistenceNotifierGuard<'a, F> {
+impl<'a, F: FnMut() -> NotifyOption> Drop for PersistenceNotifierGuard<'a, F> {
        fn drop(&mut self) {
                match (self.should_persist)() {
                        NotifyOption::DoPersist => {
@@ -1707,11 +1720,15 @@ pub enum ChannelShutdownState {
 pub enum RecentPaymentDetails {
        /// When an invoice was requested and thus a payment has not yet been sent.
        AwaitingInvoice {
-               /// Identifier for the payment to ensure idempotency.
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
                payment_id: PaymentId,
        },
        /// When a payment is still being sent and awaiting successful delivery.
        Pending {
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
+               payment_id: PaymentId,
                /// Hash of the payment that is currently being sent but has yet to be fulfilled or
                /// abandoned.
                payment_hash: PaymentHash,
@@ -1723,6 +1740,9 @@ pub enum RecentPaymentDetails {
        /// been resolved. Upon receiving [`Event::PaymentSent`], we delay for a few minutes before the
        /// payment is removed from tracking.
        Fulfilled {
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
+               payment_id: PaymentId,
                /// Hash of the payment that was claimed. `None` for serializations of [`ChannelManager`]
                /// made before LDK version 0.0.104.
                payment_hash: Option<PaymentHash>,
@@ -1731,6 +1751,9 @@ pub enum RecentPaymentDetails {
        /// abandoned via [`ChannelManager::abandon_payment`], it is marked as abandoned until all
        /// pending HTLCs for this payment resolve and an [`Event::PaymentFailed`] is generated.
        Abandoned {
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
+               payment_id: PaymentId,
                /// Hash of the payment that we have given up trying to send.
                payment_hash: PaymentHash,
        },
@@ -2475,15 +2498,16 @@ where
                                },
                                PendingOutboundPayment::Retryable { payment_hash, total_msat, .. } => {
                                        Some(RecentPaymentDetails::Pending {
+                                               payment_id: *payment_id,
                                                payment_hash: *payment_hash,
                                                total_msat: *total_msat,
                                        })
                                },
                                PendingOutboundPayment::Abandoned { payment_hash, .. } => {
-                                       Some(RecentPaymentDetails::Abandoned { payment_hash: *payment_hash })
+                                       Some(RecentPaymentDetails::Abandoned { payment_id: *payment_id, payment_hash: *payment_hash })
                                },
                                PendingOutboundPayment::Fulfilled { payment_hash, .. } => {
-                                       Some(RecentPaymentDetails::Fulfilled { payment_hash: *payment_hash })
+                                       Some(RecentPaymentDetails::Fulfilled { payment_id: *payment_id, payment_hash: *payment_hash })
                                },
                                PendingOutboundPayment::Legacy { .. } => None
                        })
@@ -2784,7 +2808,7 @@ where
                let (short_channel_id, amt_to_forward, outgoing_cltv_value) = match hop_data {
                        msgs::InboundOnionPayload::Forward { short_channel_id, amt_to_forward, outgoing_cltv_value } =>
                                (short_channel_id, amt_to_forward, outgoing_cltv_value),
-                       msgs::InboundOnionPayload::Receive { .. } =>
+                       msgs::InboundOnionPayload::Receive { .. } | msgs::InboundOnionPayload::BlindedReceive { .. } =>
                                return Err(InboundOnionErr {
                                        msg: "Final Node OnionHopData provided for us as an intermediary node",
                                        err_code: 0x4000 | 22,
@@ -2816,12 +2840,19 @@ where
                                payment_data, keysend_preimage, custom_tlvs, amt_msat, outgoing_cltv_value, payment_metadata, ..
                        } =>
                                (payment_data, keysend_preimage, custom_tlvs, amt_msat, outgoing_cltv_value, payment_metadata),
-                       _ =>
+                       msgs::InboundOnionPayload::BlindedReceive {
+                               amt_msat, total_msat, outgoing_cltv_value, payment_secret, ..
+                       } => {
+                               let payment_data = msgs::FinalOnionHopData { payment_secret, total_msat };
+                               (Some(payment_data), None, Vec::new(), amt_msat, outgoing_cltv_value, None)
+                       }
+                       msgs::InboundOnionPayload::Forward { .. } => {
                                return Err(InboundOnionErr {
                                        err_code: 0x4000|22,
                                        err_data: Vec::new(),
                                        msg: "Got non final data with an HMAC of 0",
-                               }),
+                               })
+                       },
                };
                // final_incorrect_cltv_expiry
                if outgoing_cltv_value > cltv_expiry {
@@ -2961,7 +2992,10 @@ where
                        }
                }
 
-               let next_hop = match onion_utils::decode_next_payment_hop(shared_secret, &msg.onion_routing_packet.hop_data[..], msg.onion_routing_packet.hmac, msg.payment_hash) {
+               let next_hop = match onion_utils::decode_next_payment_hop(
+                       shared_secret, &msg.onion_routing_packet.hop_data[..], msg.onion_routing_packet.hmac,
+                       msg.payment_hash, &self.node_signer
+               ) {
                        Ok(res) => res,
                        Err(onion_utils::OnionDecodeErr::Malformed { err_msg, err_code }) => {
                                return_malformed_err!(err_msg, err_code);
@@ -2983,7 +3017,9 @@ where
                        // We'll do receive checks in [`Self::construct_pending_htlc_info`] so we have access to the
                        // inbound channel's state.
                        onion_utils::Hop::Receive { .. } => return Ok((next_hop, shared_secret, None)),
-                       onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionPayload::Receive { .. }, .. } => {
+                       onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionPayload::Receive { .. }, .. } |
+                               onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionPayload::BlindedReceive { .. }, .. } =>
+                       {
                                return_err!("Final Node OnionHopData provided for us as an intermediary node", 0x4000 | 22, &[0; 0]);
                        }
                };
@@ -3523,6 +3559,116 @@ where
                outbound_payment::payment_is_probe(payment_hash, payment_id, self.probing_cookie_secret)
        }
 
+       /// Sends payment probes over all paths of a route that would be used to pay the given
+       /// amount to the given `node_id`.
+       ///
+       /// See [`ChannelManager::send_preflight_probes`] for more information.
+       pub fn send_spontaneous_preflight_probes(
+               &self, node_id: PublicKey, amount_msat: u64, final_cltv_expiry_delta: u32, 
+               liquidity_limit_multiplier: Option<u64>,
+       ) -> Result<Vec<(PaymentHash, PaymentId)>, ProbeSendFailure> {
+               let payment_params =
+                       PaymentParameters::from_node_id(node_id, final_cltv_expiry_delta);
+
+               let route_params = RouteParameters { payment_params, final_value_msat: amount_msat };
+
+               self.send_preflight_probes(route_params, liquidity_limit_multiplier)
+       }
+
+       /// Sends payment probes over all paths of a route that would be used to pay a route found
+       /// according to the given [`RouteParameters`].
+       ///
+       /// This may be used to send "pre-flight" probes, i.e., to train our scorer before conducting
+       /// the actual payment. Note this is only useful if there likely is sufficient time for the
+       /// probe to settle before sending out the actual payment, e.g., when waiting for user
+       /// confirmation in a wallet UI.
+       ///
+       /// Otherwise, there is a chance the probe could take up some liquidity needed to complete the
+       /// actual payment. Users should therefore be cautious and might avoid sending probes if
+       /// liquidity is scarce and/or they don't expect the probe to return before they send the
+       /// payment. To mitigate this issue, channels with available liquidity less than the required
+       /// amount times the given `liquidity_limit_multiplier` won't be used to send pre-flight
+       /// probes. If `None` is given as `liquidity_limit_multiplier`, it defaults to `3`.
+       pub fn send_preflight_probes(
+               &self, route_params: RouteParameters, liquidity_limit_multiplier: Option<u64>,
+       ) -> Result<Vec<(PaymentHash, PaymentId)>, ProbeSendFailure> {
+               let liquidity_limit_multiplier = liquidity_limit_multiplier.unwrap_or(3);
+
+               let payer = self.get_our_node_id();
+               let usable_channels = self.list_usable_channels();
+               let first_hops = usable_channels.iter().collect::<Vec<_>>();
+               let inflight_htlcs = self.compute_inflight_htlcs();
+
+               let route = self
+                       .router
+                       .find_route(&payer, &route_params, Some(&first_hops), inflight_htlcs)
+                       .map_err(|e| {
+                               log_error!(self.logger, "Failed to find path for payment probe: {:?}", e);
+                               ProbeSendFailure::RouteNotFound
+                       })?;
+
+               let mut used_liquidity_map = HashMap::with_capacity(first_hops.len());
+
+               let mut res = Vec::new();
+
+               for mut path in route.paths {
+                       // If the last hop is probably an unannounced channel we refrain from probing all the
+                       // way through to the end and instead probe up to the second-to-last channel.
+                       while let Some(last_path_hop) = path.hops.last() {
+                               if last_path_hop.maybe_announced_channel {
+                                       // We found a potentially announced last hop.
+                                       break;
+                               } else {
+                                       // Drop the last hop, as it's likely unannounced.
+                                       log_debug!(
+                                               self.logger,
+                                               "Avoided sending payment probe all the way to last hop {} as it is likely unannounced.",
+                                               last_path_hop.short_channel_id
+                                       );
+                                       let final_value_msat = path.final_value_msat();
+                                       path.hops.pop();
+                                       if let Some(new_last) = path.hops.last_mut() {
+                                               new_last.fee_msat += final_value_msat;
+                                       }
+                               }
+                       }
+
+                       if path.hops.len() < 2 {
+                               log_debug!(
+                                       self.logger,
+                                       "Skipped sending payment probe over path with less than two hops."
+                               );
+                               continue;
+                       }
+
+                       if let Some(first_path_hop) = path.hops.first() {
+                               if let Some(first_hop) = first_hops.iter().find(|h| {
+                                       h.get_outbound_payment_scid() == Some(first_path_hop.short_channel_id)
+                               }) {
+                                       let path_value = path.final_value_msat() + path.fee_msat();
+                                       let used_liquidity =
+                                               used_liquidity_map.entry(first_path_hop.short_channel_id).or_insert(0);
+
+                                       if first_hop.next_outbound_htlc_limit_msat
+                                               < (*used_liquidity + path_value) * liquidity_limit_multiplier
+                                       {
+                                               log_debug!(self.logger, "Skipped sending payment probe to avoid putting channel {} under the liquidity limit.", first_path_hop.short_channel_id);
+                                               continue;
+                                       } else {
+                                               *used_liquidity += path_value;
+                                       }
+                               }
+                       }
+
+                       res.push(self.send_probe(path).map_err(|e| {
+                               log_error!(self.logger, "Failed to send pre-flight probe: {:?}", e);
+                               ProbeSendFailure::SendingFailed(e)
+                       })?);
+               }
+
+               Ok(res)
+       }
+
        /// Handles the generation of a funding transaction, optionally (for tests) with a function
        /// which checks the correctness of the funding transaction given the associated channel.
        fn funding_transaction_generated_intern<FundingOutput: Fn(&OutboundV1Channel<SP>, &Transaction) -> Result<OutPoint, APIError>>(
@@ -3970,7 +4116,10 @@ where
                                                                                        let phantom_pubkey_res = self.node_signer.get_node_id(Recipient::PhantomNode);
                                                                                        if phantom_pubkey_res.is_ok() && fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, short_chan_id, &self.genesis_hash) {
                                                                                                let phantom_shared_secret = self.node_signer.ecdh(Recipient::PhantomNode, &onion_packet.public_key.unwrap(), None).unwrap().secret_bytes();
-                                                                                               let next_hop = match onion_utils::decode_next_payment_hop(phantom_shared_secret, &onion_packet.hop_data, onion_packet.hmac, payment_hash) {
+                                                                                               let next_hop = match onion_utils::decode_next_payment_hop(
+                                                                                                       phantom_shared_secret, &onion_packet.hop_data, onion_packet.hmac,
+                                                                                                       payment_hash, &self.node_signer
+                                                                                               ) {
                                                                                                        Ok(res) => res,
                                                                                                        Err(onion_utils::OnionDecodeErr::Malformed { err_msg, err_code }) => {
                                                                                                                let sha256_of_onion = Sha256::hash(&onion_packet.hop_data).into_inner();
@@ -5209,11 +5358,17 @@ where
                self.pending_outbound_payments.finalize_claims(sources, &self.pending_events);
        }
 
-       fn claim_funds_internal(&self, source: HTLCSource, payment_preimage: PaymentPreimage, forwarded_htlc_value_msat: Option<u64>, from_onchain: bool, next_channel_outpoint: OutPoint) {
+       fn claim_funds_internal(&self, source: HTLCSource, payment_preimage: PaymentPreimage,
+               forwarded_htlc_value_msat: Option<u64>, from_onchain: bool,
+               next_channel_counterparty_node_id: Option<PublicKey>, next_channel_outpoint: OutPoint
+       ) {
                match source {
                        HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } => {
                                debug_assert!(self.background_events_processed_since_startup.load(Ordering::Acquire),
                                        "We don't support claim_htlc claims during startup - monitors may not be available yet");
+                               if let Some(pubkey) = next_channel_counterparty_node_id {
+                                       debug_assert_eq!(pubkey, path.hops[0].pubkey);
+                               }
                                let ev_completion_action = EventCompletionAction::ReleaseRAAChannelMonitorUpdate {
                                        channel_funding_outpoint: next_channel_outpoint,
                                        counterparty_node_id: path.hops[0].pubkey,
@@ -5224,6 +5379,7 @@ where
                        },
                        HTLCSource::PreviousHopData(hop_data) => {
                                let prev_outpoint = hop_data.outpoint;
+                               let completed_blocker = RAAMonitorUpdateBlockingAction::from_prev_hop_data(&hop_data);
                                let res = self.claim_funds_from_hop(hop_data, payment_preimage,
                                        |htlc_claim_value_msat| {
                                                if let Some(forwarded_htlc_value) = forwarded_htlc_value_msat {
@@ -5239,7 +5395,17 @@ where
                                                                        next_channel_id: Some(next_channel_outpoint.to_channel_id()),
                                                                        outbound_amount_forwarded_msat: forwarded_htlc_value_msat,
                                                                },
-                                                               downstream_counterparty_and_funding_outpoint: None,
+                                                               downstream_counterparty_and_funding_outpoint:
+                                                                       if let Some(node_id) = next_channel_counterparty_node_id {
+                                                                               Some((node_id, next_channel_outpoint, completed_blocker))
+                                                                       } else {
+                                                                               // We can only get `None` here if we are processing a
+                                                                               // `ChannelMonitor`-originated event, in which case we
+                                                                               // don't care about ensuring we wake the downstream
+                                                                               // channel's monitor updating - the channel is already
+                                                                               // closed.
+                                                                               None
+                                                                       },
                                                        })
                                                } else { None }
                                        });
@@ -6087,6 +6253,17 @@ where
                                hash_map::Entry::Occupied(mut chan_phase_entry) => {
                                        if let ChannelPhase::Funded(chan) = chan_phase_entry.get_mut() {
                                                let res = try_chan_phase_entry!(self, chan.update_fulfill_htlc(&msg), chan_phase_entry);
+                                               if let HTLCSource::PreviousHopData(prev_hop) = &res.0 {
+                                                       peer_state.actions_blocking_raa_monitor_updates.entry(msg.channel_id)
+                                                               .or_insert_with(Vec::new)
+                                                               .push(RAAMonitorUpdateBlockingAction::from_prev_hop_data(&prev_hop));
+                                               }
+                                               // Note that we do not need to push an `actions_blocking_raa_monitor_updates`
+                                               // entry here, even though we *do* need to block the next RAA monitor update.
+                                               // We do this instead in the `claim_funds_internal` by attaching a
+                                               // `ReleaseRAAChannelMonitorUpdate` action to the event generated when the
+                                               // outbound HTLC is claimed. This is guaranteed to all complete before we
+                                               // process the RAA as messages are processed from single peers serially.
                                                funding_txo = chan.context.get_funding_txo().expect("We won't accept a fulfill until funded");
                                                res
                                        } else {
@@ -6097,7 +6274,7 @@ where
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
                        }
                };
-               self.claim_funds_internal(htlc_source, msg.payment_preimage.clone(), Some(forwarded_htlc_value), false, funding_txo);
+               self.claim_funds_internal(htlc_source, msg.payment_preimage.clone(), Some(forwarded_htlc_value), false, Some(*counterparty_node_id), funding_txo);
                Ok(())
        }
 
@@ -6303,6 +6480,23 @@ where
                })
        }
 
+       #[cfg(any(test, feature = "_test_utils"))]
+       pub(crate) fn test_raa_monitor_updates_held(&self,
+               counterparty_node_id: PublicKey, channel_id: ChannelId
+       ) -> bool {
+               let per_peer_state = self.per_peer_state.read().unwrap();
+               if let Some(peer_state_mtx) = per_peer_state.get(&counterparty_node_id) {
+                       let mut peer_state_lck = peer_state_mtx.lock().unwrap();
+                       let peer_state = &mut *peer_state_lck;
+
+                       if let Some(chan) = peer_state.channel_by_id.get(&channel_id) {
+                               return self.raa_monitor_updates_held(&peer_state.actions_blocking_raa_monitor_updates,
+                                       chan.context().get_funding_txo().unwrap(), counterparty_node_id);
+                       }
+               }
+               false
+       }
+
        fn internal_revoke_and_ack(&self, counterparty_node_id: &PublicKey, msg: &msgs::RevokeAndACK) -> Result<(), MsgHandleErrInternal> {
                let (htlcs_to_fail, res) = {
                        let per_peer_state = self.per_peer_state.read().unwrap();
@@ -6446,7 +6640,7 @@ where
                Ok(NotifyOption::DoPersist)
        }
 
-       fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
+       fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<NotifyOption, MsgHandleErrInternal> {
                let htlc_forwards;
                let need_lnd_workaround = {
                        let per_peer_state = self.per_peer_state.read().unwrap();
@@ -6502,14 +6696,16 @@ where
                        }
                };
 
+               let mut persist = NotifyOption::SkipPersistHandleEvents;
                if let Some(forwards) = htlc_forwards {
                        self.forward_htlcs(&mut [forwards][..]);
+                       persist = NotifyOption::DoPersist;
                }
 
                if let Some(channel_ready_msg) = need_lnd_workaround {
                        self.internal_channel_ready(counterparty_node_id, &channel_ready_msg)?;
                }
-               Ok(())
+               Ok(persist)
        }
 
        /// Process pending events from the [`chain::Watch`], returning whether any events were processed.
@@ -6524,8 +6720,8 @@ where
                                match monitor_event {
                                        MonitorEvent::HTLCEvent(htlc_update) => {
                                                if let Some(preimage) = htlc_update.payment_preimage {
-                                                       log_trace!(self.logger, "Claiming HTLC with preimage {} from our monitor", &preimage);
-                                                       self.claim_funds_internal(htlc_update.source, preimage, htlc_update.htlc_value_satoshis.map(|v| v * 1000), true, funding_outpoint);
+                                                       log_trace!(self.logger, "Claiming HTLC with preimage {} from our monitor", preimage);
+                                                       self.claim_funds_internal(htlc_update.source, preimage, htlc_update.htlc_value_satoshis.map(|v| v * 1000), true, counterparty_node_id, funding_outpoint);
                                                } else {
                                                        log_trace!(self.logger, "Failing HTLC with hash {} from our monitor", &htlc_update.payment_hash);
                                                        let receiver = HTLCDestination::NextHopChannel { node_id: counterparty_node_id, channel_id: funding_outpoint.to_channel_id() };
@@ -7668,18 +7864,28 @@ where
                        if let Ok(persist) = handle_error!(self, self.internal_channel_update(counterparty_node_id, msg), *counterparty_node_id) {
                                persist
                        } else {
-                               NotifyOption::SkipPersistNoEvents
+                               NotifyOption::DoPersist
                        }
                });
        }
 
        fn handle_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_channel_reestablish(counterparty_node_id, msg), *counterparty_node_id);
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_channel_reestablish(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               Err(_) => NotifyOption::SkipPersistHandleEvents,
+                               Ok(persist) => *persist,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn peer_disconnected(&self, counterparty_node_id: &PublicKey) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(
+                       self, || NotifyOption::SkipPersistHandleEvents);
+
                let mut failed_channels = Vec::new();
                let mut per_peer_state = self.per_peer_state.write().unwrap();
                let remove_peer = {
@@ -7778,76 +7984,82 @@ where
                        return Err(());
                }
 
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+               let mut res = Ok(());
 
-               // If we have too many peers connected which don't have funded channels, disconnect the
-               // peer immediately (as long as it doesn't have funded channels). If we have a bunch of
-               // unfunded channels taking up space in memory for disconnected peers, we still let new
-               // peers connect, but we'll reject new channels from them.
-               let connected_peers_without_funded_channels = self.peers_without_funded_channels(|node| node.is_connected);
-               let inbound_peer_limited = inbound && connected_peers_without_funded_channels >= MAX_NO_CHANNEL_PEERS;
+               PersistenceNotifierGuard::optionally_notify(self, || {
+                       // If we have too many peers connected which don't have funded channels, disconnect the
+                       // peer immediately (as long as it doesn't have funded channels). If we have a bunch of
+                       // unfunded channels taking up space in memory for disconnected peers, we still let new
+                       // peers connect, but we'll reject new channels from them.
+                       let connected_peers_without_funded_channels = self.peers_without_funded_channels(|node| node.is_connected);
+                       let inbound_peer_limited = inbound && connected_peers_without_funded_channels >= MAX_NO_CHANNEL_PEERS;
 
-               {
-                       let mut peer_state_lock = self.per_peer_state.write().unwrap();
-                       match peer_state_lock.entry(counterparty_node_id.clone()) {
-                               hash_map::Entry::Vacant(e) => {
-                                       if inbound_peer_limited {
-                                               return Err(());
-                                       }
-                                       e.insert(Mutex::new(PeerState {
-                                               channel_by_id: HashMap::new(),
-                                               inbound_channel_request_by_id: HashMap::new(),
-                                               latest_features: init_msg.features.clone(),
-                                               pending_msg_events: Vec::new(),
-                                               in_flight_monitor_updates: BTreeMap::new(),
-                                               monitor_update_blocked_actions: BTreeMap::new(),
-                                               actions_blocking_raa_monitor_updates: BTreeMap::new(),
-                                               is_connected: true,
-                                       }));
-                               },
-                               hash_map::Entry::Occupied(e) => {
-                                       let mut peer_state = e.get().lock().unwrap();
-                                       peer_state.latest_features = init_msg.features.clone();
-
-                                       let best_block_height = self.best_block.read().unwrap().height();
-                                       if inbound_peer_limited &&
-                                               Self::unfunded_channel_count(&*peer_state, best_block_height) ==
-                                               peer_state.channel_by_id.len()
-                                       {
-                                               return Err(());
-                                       }
+                       {
+                               let mut peer_state_lock = self.per_peer_state.write().unwrap();
+                               match peer_state_lock.entry(counterparty_node_id.clone()) {
+                                       hash_map::Entry::Vacant(e) => {
+                                               if inbound_peer_limited {
+                                                       res = Err(());
+                                                       return NotifyOption::SkipPersistNoEvents;
+                                               }
+                                               e.insert(Mutex::new(PeerState {
+                                                       channel_by_id: HashMap::new(),
+                                                       inbound_channel_request_by_id: HashMap::new(),
+                                                       latest_features: init_msg.features.clone(),
+                                                       pending_msg_events: Vec::new(),
+                                                       in_flight_monitor_updates: BTreeMap::new(),
+                                                       monitor_update_blocked_actions: BTreeMap::new(),
+                                                       actions_blocking_raa_monitor_updates: BTreeMap::new(),
+                                                       is_connected: true,
+                                               }));
+                                       },
+                                       hash_map::Entry::Occupied(e) => {
+                                               let mut peer_state = e.get().lock().unwrap();
+                                               peer_state.latest_features = init_msg.features.clone();
+
+                                               let best_block_height = self.best_block.read().unwrap().height();
+                                               if inbound_peer_limited &&
+                                                       Self::unfunded_channel_count(&*peer_state, best_block_height) ==
+                                                       peer_state.channel_by_id.len()
+                                               {
+                                                       res = Err(());
+                                                       return NotifyOption::SkipPersistNoEvents;
+                                               }
 
-                                       debug_assert!(!peer_state.is_connected, "A peer shouldn't be connected twice");
-                                       peer_state.is_connected = true;
-                               },
+                                               debug_assert!(!peer_state.is_connected, "A peer shouldn't be connected twice");
+                                               peer_state.is_connected = true;
+                                       },
+                               }
                        }
-               }
 
-               log_debug!(self.logger, "Generating channel_reestablish events for {}", log_pubkey!(counterparty_node_id));
+                       log_debug!(self.logger, "Generating channel_reestablish events for {}", log_pubkey!(counterparty_node_id));
 
-               let per_peer_state = self.per_peer_state.read().unwrap();
-               if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
-                       let mut peer_state_lock = peer_state_mutex.lock().unwrap();
-                       let peer_state = &mut *peer_state_lock;
-                       let pending_msg_events = &mut peer_state.pending_msg_events;
+                       let per_peer_state = self.per_peer_state.read().unwrap();
+                       if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
+                               let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+                               let peer_state = &mut *peer_state_lock;
+                               let pending_msg_events = &mut peer_state.pending_msg_events;
 
-                       peer_state.channel_by_id.iter_mut().filter_map(|(_, phase)|
-                               if let ChannelPhase::Funded(chan) = phase { Some(chan) } else {
-                                       // Since unfunded channel maps are cleared upon disconnecting a peer, and they're not persisted
-                                       // (so won't be recovered after a crash), they shouldn't exist here and we would never need to
-                                       // worry about closing and removing them.
-                                       debug_assert!(false);
-                                       None
-                               }
-                       ).for_each(|chan| {
-                               pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
-                                       node_id: chan.context.get_counterparty_node_id(),
-                                       msg: chan.get_channel_reestablish(&self.logger),
+                               peer_state.channel_by_id.iter_mut().filter_map(|(_, phase)|
+                                       if let ChannelPhase::Funded(chan) = phase { Some(chan) } else {
+                                               // Since unfunded channel maps are cleared upon disconnecting a peer, and they're not persisted
+                                               // (so won't be recovered after a crash), they shouldn't exist here and we would never need to
+                                               // worry about closing and removing them.
+                                               debug_assert!(false);
+                                               None
+                                       }
+                               ).for_each(|chan| {
+                                       pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
+                                               node_id: chan.context.get_counterparty_node_id(),
+                                               msg: chan.get_channel_reestablish(&self.logger),
+                                       });
                                });
-                       });
-               }
-               //TODO: Also re-broadcast announcement_signatures
-               Ok(())
+                       }
+
+                       return NotifyOption::SkipPersistHandleEvents;
+                       //TODO: Also re-broadcast announcement_signatures
+               });
+               res
        }
 
        fn handle_error(&self, counterparty_node_id: &PublicKey, msg: &msgs::ErrorMessage) {
@@ -9429,6 +9641,7 @@ where
                                                                        // downstream chan is closed (because we don't have a
                                                                        // channel_id -> peer map entry).
                                                                        counterparty_opt.is_none(),
+                                                                       counterparty_opt.cloned().or(monitor.get_counterparty_node_id()),
                                                                        monitor.get_funding_txo().0))
                                                        } else { None }
                                                } else {
@@ -9709,12 +9922,12 @@ where
                        channel_manager.fail_htlc_backwards_internal(&source, &payment_hash, &reason, receiver);
                }
 
-               for (source, preimage, downstream_value, downstream_closed, downstream_funding) in pending_claims_to_replay {
+               for (source, preimage, downstream_value, downstream_closed, downstream_node_id, downstream_funding) in pending_claims_to_replay {
                        // We use `downstream_closed` in place of `from_onchain` here just as a guess - we
                        // don't remember in the `ChannelMonitor` where we got a preimage from, but if the
                        // channel is closed we just assume that it probably came from an on-chain claim.
                        channel_manager.claim_funds_internal(source, preimage, Some(downstream_value),
-                               downstream_closed, downstream_funding);
+                               downstream_closed, downstream_node_id, downstream_funding);
                }
 
                //TODO: Broadcast channel update for closed channels, but only after we've made a
@@ -9969,7 +10182,7 @@ mod tests {
 
                // To start (1), send a regular payment but don't claim it.
                let expected_route = [&nodes[1]];
-               let (payment_preimage, payment_hash, _) = route_payment(&nodes[0], &expected_route, 100_000);
+               let (payment_preimage, payment_hash, ..) = route_payment(&nodes[0], &expected_route, 100_000);
 
                // Next, attempt a keysend payment and make sure it fails.
                let route_params = RouteParameters::from_payment_params_and_value(