Handle sign_counterparty_commitment failing during inb funding
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 2aa2aab2a80e7b061763f08fd43761c2b044e1eb..56820a6c480f93c1acb1aaebf3306bd156ff0889 100644 (file)
@@ -43,7 +43,7 @@ use crate::events::{Event, EventHandler, EventsProvider, MessageSendEvent, Messa
 // construct one themselves.
 use crate::ln::{inbound_payment, ChannelId, PaymentHash, PaymentPreimage, PaymentSecret};
 use crate::ln::channel::{Channel, ChannelPhase, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UnfundedChannelContext, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel};
-use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
+use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
 #[cfg(any(feature = "_test_utils", test))]
 use crate::ln::features::Bolt11InvoiceFeatures;
 use crate::routing::gossip::NetworkGraph;
@@ -55,13 +55,15 @@ use crate::ln::onion_utils::HTLCFailReason;
 use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
 #[cfg(test)]
 use crate::ln::outbound_payment;
-use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration};
+use crate::ln::outbound_payment::{Bolt12PaymentError, OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration};
 use crate::ln::wire::Encode;
-use crate::offers::invoice::{BlindedPayInfo, DEFAULT_RELATIVE_EXPIRY};
+use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, InvoiceBuilder};
+use crate::offers::invoice_error::InvoiceError;
+use crate::offers::merkle::SignError;
 use crate::offers::offer::{DerivedMetadata, Offer, OfferBuilder};
 use crate::offers::parse::Bolt12SemanticError;
 use crate::offers::refund::{Refund, RefundBuilder};
-use crate::onion_message::{Destination, OffersMessage, PendingOnionMessage};
+use crate::onion_message::{Destination, OffersMessage, OffersMessageHandler, PendingOnionMessage, new_pending_onion_message};
 use crate::sign::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, WriteableEcdsaChannelSigner};
 use crate::util::config::{UserConfig, ChannelConfig, ChannelConfigUpdate};
 use crate::util::wakers::{Future, Notifier};
@@ -825,7 +827,8 @@ struct PendingInboundPayment {
 /// or, respectively, [`Router`] for its router, but this type alias chooses the concrete types
 /// of [`KeysManager`] and [`DefaultRouter`].
 ///
-/// This is not exported to bindings users as Arcs don't make sense in bindings
+/// This is not exported to bindings users as type aliases aren't supported in most languages.
+#[cfg(not(c_bindings))]
 pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<
        Arc<M>,
        Arc<T>,
@@ -853,7 +856,8 @@ pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<
 /// or, respectively, [`Router`]  for its router, but this type alias chooses the concrete types
 /// of [`KeysManager`] and [`DefaultRouter`].
 ///
-/// This is not exported to bindings users as Arcs don't make sense in bindings
+/// This is not exported to bindings users as type aliases aren't supported in most languages.
+#[cfg(not(c_bindings))]
 pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> =
        ChannelManager<
                &'a M,
@@ -2679,11 +2683,11 @@ where
        /// will be accepted on the given channel, and after additional timeout/the closing of all
        /// pending HTLCs, the channel will be closed on chain.
        ///
-       ///  * If we are the channel initiator, we will pay between our [`Background`] and
-       ///    [`ChannelConfig::force_close_avoidance_max_fee_satoshis`] plus our [`Normal`] fee
-       ///    estimate.
+       ///  * If we are the channel initiator, we will pay between our [`ChannelCloseMinimum`] and
+       ///    [`ChannelConfig::force_close_avoidance_max_fee_satoshis`] plus our [`NonAnchorChannelFee`]
+       ///    fee estimate.
        ///  * If our counterparty is the channel initiator, we will require a channel closing
-       ///    transaction feerate of at least our [`Background`] feerate or the feerate which
+       ///    transaction feerate of at least our [`ChannelCloseMinimum`] feerate or the feerate which
        ///    would appear on a force-closure transaction, whichever is lower. We will allow our
        ///    counterparty to pay as much fee as they'd like, however.
        ///
@@ -2695,8 +2699,8 @@ where
        /// channel.
        ///
        /// [`ChannelConfig::force_close_avoidance_max_fee_satoshis`]: crate::util::config::ChannelConfig::force_close_avoidance_max_fee_satoshis
-       /// [`Background`]: crate::chain::chaininterface::ConfirmationTarget::Background
-       /// [`Normal`]: crate::chain::chaininterface::ConfirmationTarget::Normal
+       /// [`ChannelCloseMinimum`]: crate::chain::chaininterface::ConfirmationTarget::ChannelCloseMinimum
+       /// [`NonAnchorChannelFee`]: crate::chain::chaininterface::ConfirmationTarget::NonAnchorChannelFee
        /// [`SendShutdown`]: crate::events::MessageSendEvent::SendShutdown
        pub fn close_channel(&self, channel_id: &ChannelId, counterparty_node_id: &PublicKey) -> Result<(), APIError> {
                self.close_channel_internal(channel_id, counterparty_node_id, None, None)
@@ -2710,8 +2714,8 @@ where
        /// the channel being closed or not:
        ///  * If we are the channel initiator, we will pay at least this feerate on the closing
        ///    transaction. The upper-bound is set by
-       ///    [`ChannelConfig::force_close_avoidance_max_fee_satoshis`] plus our [`Normal`] fee
-       ///    estimate (or `target_feerate_sat_per_1000_weight`, if it is greater).
+       ///    [`ChannelConfig::force_close_avoidance_max_fee_satoshis`] plus our [`NonAnchorChannelFee`]
+       ///    fee estimate (or `target_feerate_sat_per_1000_weight`, if it is greater).
        ///  * If our counterparty is the channel initiator, we will refuse to accept a channel closure
        ///    transaction feerate below `target_feerate_sat_per_1000_weight` (or the feerate which
        ///    will appear on a force-closure transaction, whichever is lower).
@@ -2729,8 +2733,7 @@ where
        /// channel.
        ///
        /// [`ChannelConfig::force_close_avoidance_max_fee_satoshis`]: crate::util::config::ChannelConfig::force_close_avoidance_max_fee_satoshis
-       /// [`Background`]: crate::chain::chaininterface::ConfirmationTarget::Background
-       /// [`Normal`]: crate::chain::chaininterface::ConfirmationTarget::Normal
+       /// [`NonAnchorChannelFee`]: crate::chain::chaininterface::ConfirmationTarget::NonAnchorChannelFee
        /// [`SendShutdown`]: crate::events::MessageSendEvent::SendShutdown
        pub fn close_channel_with_feerate_and_script(&self, channel_id: &ChannelId, counterparty_node_id: &PublicKey, target_feerate_sats_per_1000_weight: Option<u32>, shutdown_script: Option<ShutdownScript>) -> Result<(), APIError> {
                self.close_channel_internal(channel_id, counterparty_node_id, target_feerate_sats_per_1000_weight, shutdown_script)
@@ -3579,6 +3582,17 @@ where
                self.pending_outbound_payments.test_set_payment_metadata(payment_id, new_payment_metadata);
        }
 
+       pub(super) fn send_payment_for_bolt12_invoice(&self, invoice: &Bolt12Invoice, payment_id: PaymentId) -> Result<(), Bolt12PaymentError> {
+               let best_block_height = self.best_block.read().unwrap().height();
+               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+               self.pending_outbound_payments
+                       .send_payment_for_bolt12_invoice(
+                               invoice, payment_id, &self.router, self.list_usable_channels(),
+                               || self.compute_inflight_htlcs(), &self.entropy_source, &self.node_signer,
+                               best_block_height, &self.logger, &self.pending_events,
+                               |args| self.send_payment_along_path(args)
+                       )
+       }
 
        /// Signals that no further attempts for the given payment should occur. Useful if you have a
        /// pending outbound payment with retries remaining, but wish to stop retrying the payment before
@@ -3593,10 +3607,20 @@ where
        /// wait until you receive either a [`Event::PaymentFailed`] or [`Event::PaymentSent`] event to
        /// determine the ultimate status of a payment.
        ///
+       /// # Requested Invoices
+       ///
+       /// In the case of paying a [`Bolt12Invoice`] via [`ChannelManager::pay_for_offer`], abandoning
+       /// the payment prior to receiving the invoice will result in an [`Event::InvoiceRequestFailed`]
+       /// and prevent any attempts at paying it once received. The other events may only be generated
+       /// once the invoice has been received.
+       ///
        /// # Restart Behavior
        ///
        /// If an [`Event::PaymentFailed`] is generated and we restart without first persisting the
-       /// [`ChannelManager`], another [`Event::PaymentFailed`] may be generated.
+       /// [`ChannelManager`], another [`Event::PaymentFailed`] may be generated; likewise for
+       /// [`Event::InvoiceRequestFailed`].
+       ///
+       /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn abandon_payment(&self, payment_id: PaymentId) {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.abandon_payment(payment_id, PaymentFailureReason::UserAbandoned, &self.pending_events);
@@ -3779,7 +3803,7 @@ where
 
                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                let peer_state = &mut *peer_state_lock;
-               let (chan, msg) = match peer_state.channel_by_id.remove(temporary_channel_id) {
+               let (chan, msg_opt) = match peer_state.channel_by_id.remove(temporary_channel_id) {
                        Some(ChannelPhase::UnfundedOutboundV1(chan)) => {
                                let funding_txo = find_funding_output(&chan, &funding_transaction)?;
 
@@ -3818,10 +3842,12 @@ where
                                }),
                };
 
-               peer_state.pending_msg_events.push(events::MessageSendEvent::SendFundingCreated {
-                       node_id: chan.context.get_counterparty_node_id(),
-                       msg,
-               });
+               if let Some(msg) = msg_opt {
+                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendFundingCreated {
+                               node_id: chan.context.get_counterparty_node_id(),
+                               msg,
+                       });
+               }
                match peer_state.channel_by_id.entry(chan.context.channel_id()) {
                        hash_map::Entry::Occupied(_) => {
                                panic!("Generated duplicate funding txid?");
@@ -4794,8 +4820,8 @@ where
                PersistenceNotifierGuard::optionally_notify(self, || {
                        let mut should_persist = NotifyOption::SkipPersistNoEvents;
 
-                       let normal_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
-                       let min_mempool_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::MempoolMinimum);
+                       let non_anchor_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::NonAnchorChannelFee);
+                       let anchor_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::AnchorChannelFee);
 
                        let per_peer_state = self.per_peer_state.read().unwrap();
                        for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
@@ -4805,9 +4831,9 @@ where
                                        |(chan_id, phase)| if let ChannelPhase::Funded(chan) = phase { Some((chan_id, chan)) } else { None }
                                ) {
                                        let new_feerate = if chan.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
-                                               min_mempool_feerate
+                                               anchor_feerate
                                        } else {
-                                               normal_feerate
+                                               non_anchor_feerate
                                        };
                                        let chan_needs_persist = self.update_channel_fee(chan_id, chan, new_feerate);
                                        if chan_needs_persist == NotifyOption::DoPersist { should_persist = NotifyOption::DoPersist; }
@@ -4843,8 +4869,8 @@ where
                PersistenceNotifierGuard::optionally_notify(self, || {
                        let mut should_persist = NotifyOption::SkipPersistNoEvents;
 
-                       let normal_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
-                       let min_mempool_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::MempoolMinimum);
+                       let non_anchor_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::NonAnchorChannelFee);
+                       let anchor_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::AnchorChannelFee);
 
                        let mut handle_errors: Vec<(Result<(), _>, _)> = Vec::new();
                        let mut timed_out_mpp_htlcs = Vec::new();
@@ -4891,9 +4917,9 @@ where
                                                match phase {
                                                        ChannelPhase::Funded(chan) => {
                                                                let new_feerate = if chan.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
-                                                                       min_mempool_feerate
+                                                                       anchor_feerate
                                                                } else {
-                                                                       normal_feerate
+                                                                       non_anchor_feerate
                                                                };
                                                                let chan_needs_persist = self.update_channel_fee(chan_id, chan, new_feerate);
                                                                if chan_needs_persist == NotifyOption::DoPersist { should_persist = NotifyOption::DoPersist; }
@@ -6206,7 +6232,7 @@ where
 
                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                let peer_state = &mut *peer_state_lock;
-               let (chan, funding_msg, monitor) =
+               let (chan, funding_msg_opt, monitor) =
                        match peer_state.channel_by_id.remove(&msg.temporary_channel_id) {
                                Some(ChannelPhase::UnfundedInboundV1(inbound_chan)) => {
                                        match inbound_chan.funding_created(msg, best_block, &self.signer_provider, &self.logger) {
@@ -6229,9 +6255,12 @@ where
                                None => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.temporary_channel_id))
                        };
 
-               match peer_state.channel_by_id.entry(funding_msg.channel_id) {
+               match peer_state.channel_by_id.entry(chan.context.channel_id()) {
                        hash_map::Entry::Occupied(_) => {
-                               Err(MsgHandleErrInternal::send_err_msg_no_close("Already had channel with the new channel_id".to_owned(), funding_msg.channel_id))
+                               Err(MsgHandleErrInternal::send_err_msg_no_close(
+                                       "Already had channel with the new channel_id".to_owned(),
+                                       chan.context.channel_id()
+                               ))
                        },
                        hash_map::Entry::Vacant(e) => {
                                let mut id_to_peer_lock = self.id_to_peer.lock().unwrap();
@@ -6239,7 +6268,7 @@ where
                                        hash_map::Entry::Occupied(_) => {
                                                return Err(MsgHandleErrInternal::send_err_msg_no_close(
                                                        "The funding_created message had the same funding_txid as an existing channel - funding is not possible".to_owned(),
-                                                       funding_msg.channel_id))
+                                                       chan.context.channel_id()))
                                        },
                                        hash_map::Entry::Vacant(i_e) => {
                                                let monitor_res = self.chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor);
@@ -6251,10 +6280,12 @@ where
                                                        // hasn't persisted to disk yet - we can't lose money on a transaction that we haven't
                                                        // accepted payment from yet. We do, however, need to wait to send our channel_ready
                                                        // until we have persisted our monitor.
-                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendFundingSigned {
-                                                               node_id: counterparty_node_id.clone(),
-                                                               msg: funding_msg,
-                                                       });
+                                                       if let Some(msg) = funding_msg_opt {
+                                                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendFundingSigned {
+                                                                       node_id: counterparty_node_id.clone(),
+                                                                       msg,
+                                                               });
+                                                       }
 
                                                        if let ChannelPhase::Funded(chan) = e.insert(ChannelPhase::Funded(chan)) {
                                                                handle_new_monitor_update!(self, persist_state, peer_state_lock, peer_state,
@@ -6265,9 +6296,13 @@ where
                                                        Ok(())
                                                } else {
                                                        log_error!(self.logger, "Persisting initial ChannelMonitor failed, implying the funding outpoint was duplicated");
+                                                       let channel_id = match funding_msg_opt {
+                                                               Some(msg) => msg.channel_id,
+                                                               None => chan.context.channel_id(),
+                                                       };
                                                        return Err(MsgHandleErrInternal::send_err_msg_no_close(
                                                                "The funding_created message had the same funding_txid as an existing channel - funding is not possible".to_owned(),
-                                                               funding_msg.channel_id));
+                                                               channel_id));
                                                }
                                        }
                                }
@@ -7295,11 +7330,20 @@ where
        /// [`ChannelManager`] when handling [`InvoiceRequest`] messages for the offer. The offer will
        /// not have an expiration unless otherwise set on the builder.
        ///
+       /// # Privacy
+       ///
        /// Uses a one-hop [`BlindedPath`] for the offer with [`ChannelManager::get_our_node_id`] as the
        /// introduction node and a derived signing pubkey for recipient privacy. As such, currently,
        /// the node must be announced. Otherwise, there is no way to find a path to the introduction
        /// node in order to send the [`InvoiceRequest`].
        ///
+       /// # Limitations
+       ///
+       /// Requires a direct connection to the introduction node in the responding [`InvoiceRequest`]'s
+       /// reply path.
+       ///
+       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
+       ///
        /// [`Offer`]: crate::offers::offer::Offer
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        pub fn create_offer_builder(
@@ -7319,21 +7363,45 @@ where
        /// Creates a [`RefundBuilder`] such that the [`Refund`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`Bolt12Invoice`] messages for the refund.
        ///
+       /// # Payment
+       ///
+       /// The provided `payment_id` is used to ensure that only one invoice is paid for the refund.
+       /// See [Avoiding Duplicate Payments] for other requirements once the payment has been sent.
+       ///
        /// The builder will have the provided expiration set. Any changes to the expiration on the
        /// returned builder will not be honored by [`ChannelManager`]. For `no-std`, the highest seen
        /// block time minus two hours is used for the current time when determining if the refund has
        /// expired.
        ///
-       /// The provided `payment_id` is used to ensure that only one invoice is paid for the refund. To
-       /// revoke the refund, use [`ChannelManager::abandon_payment`] prior to receiving the invoice.
+       /// To revoke the refund, use [`ChannelManager::abandon_payment`] prior to receiving the
+       /// invoice. If abandoned, or an invoice isn't received before expiration, the payment will fail
+       /// with an [`Event::InvoiceRequestFailed`].
+       ///
+       /// If `max_total_routing_fee_msat` is not specified, The default from
+       /// [`RouteParameters::from_payment_params_and_value`] is applied.
+       ///
+       /// # Privacy
        ///
        /// Uses a one-hop [`BlindedPath`] for the refund with [`ChannelManager::get_our_node_id`] as
-       /// the introduction node and a derived payer id for sender privacy. As such, currently, the
+       /// the introduction node and a derived payer id for payer privacy. As such, currently, the
        /// node must be announced. Otherwise, there is no way to find a path to the introduction node
        /// in order to send the [`Bolt12Invoice`].
        ///
+       /// # Limitations
+       ///
+       /// Requires a direct connection to an introduction node in the responding
+       /// [`Bolt12Invoice::payment_paths`].
+       ///
+       /// # Errors
+       ///
+       /// Errors if a duplicate `payment_id` is provided given the caveats in the aforementioned link
+       /// or if `amount_msats` is invalid.
+       ///
+       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
+       ///
        /// [`Refund`]: crate::offers::refund::Refund
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
+       /// [`Bolt12Invoice::payment_paths`]: crate::offers::invoice::Bolt12Invoice::payment_paths
        pub fn create_refund_builder(
                &self, description: String, amount_msats: u64, absolute_expiry: Duration,
                payment_id: PaymentId, retry_strategy: Retry, max_total_routing_fee_msat: Option<u64>
@@ -7373,18 +7441,43 @@ where
        /// - `amount_msats` if overpaying what is required for the given `quantity` is desired, and
        /// - `payer_note` for [`InvoiceRequest::payer_note`].
        ///
+       /// If `max_total_routing_fee_msat` is not specified, The default from
+       /// [`RouteParameters::from_payment_params_and_value`] is applied.
+       ///
+       /// # Payment
+       ///
        /// The provided `payment_id` is used to ensure that only one invoice is paid for the request
        /// when received. See [Avoiding Duplicate Payments] for other requirements once the payment has
-       /// been sent. To revoke the request, use [`ChannelManager::abandon_payment`] prior to receiving
-       /// the invoice.
+       /// been sent.
+       ///
+       /// To revoke the request, use [`ChannelManager::abandon_payment`] prior to receiving the
+       /// invoice. If abandoned, or an invoice isn't received in a reasonable amount of time, the
+       /// payment will fail with an [`Event::InvoiceRequestFailed`].
        ///
-       /// Errors if a duplicate `payment_id` is provided given the caveats in the aforementioned link.
+       /// # Privacy
+       ///
+       /// Uses a one-hop [`BlindedPath`] for the reply path with [`ChannelManager::get_our_node_id`]
+       /// as the introduction node and a derived payer id for payer privacy. As such, currently, the
+       /// node must be announced. Otherwise, there is no way to find a path to the introduction node
+       /// in order to send the [`Bolt12Invoice`].
+       ///
+       /// # Limitations
+       ///
+       /// Requires a direct connection to an introduction node in [`Offer::paths`] or to
+       /// [`Offer::signing_pubkey`], if empty. A similar restriction applies to the responding
+       /// [`Bolt12Invoice::payment_paths`].
+       ///
+       /// # Errors
+       ///
+       /// Errors if a duplicate `payment_id` is provided given the caveats in the aforementioned link
+       /// or if the provided parameters are invalid for the offer.
        ///
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        /// [`InvoiceRequest::quantity`]: crate::offers::invoice_request::InvoiceRequest::quantity
        /// [`InvoiceRequest::payer_note`]: crate::offers::invoice_request::InvoiceRequest::payer_note
        /// [`InvoiceRequestBuilder`]: crate::offers::invoice_request::InvoiceRequestBuilder
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
+       /// [`Bolt12Invoice::payment_paths`]: crate::offers::invoice::Bolt12Invoice::payment_paths
        /// [Avoiding Duplicate Payments]: #avoiding-duplicate-payments
        pub fn pay_for_offer(
                &self, offer: &Offer, quantity: Option<u64>, amount_msats: Option<u64>,
@@ -7423,11 +7516,11 @@ where
 
                let mut pending_offers_messages = self.pending_offers_messages.lock().unwrap();
                if offer.paths().is_empty() {
-                       let message = PendingOnionMessage {
-                               contents: OffersMessage::InvoiceRequest(invoice_request),
-                               destination: Destination::Node(offer.signing_pubkey()),
-                               reply_path: Some(reply_path),
-                       };
+                       let message = new_pending_onion_message(
+                               OffersMessage::InvoiceRequest(invoice_request),
+                               Destination::Node(offer.signing_pubkey()),
+                               Some(reply_path),
+                       );
                        pending_offers_messages.push(message);
                } else {
                        // Send as many invoice requests as there are paths in the offer (with an upper bound).
@@ -7435,11 +7528,11 @@ where
                        // one invoice for a given payment id will be paid, even if more than one is received.
                        const REQUEST_LIMIT: usize = 10;
                        for path in offer.paths().into_iter().take(REQUEST_LIMIT) {
-                               let message = PendingOnionMessage {
-                                       contents: OffersMessage::InvoiceRequest(invoice_request.clone()),
-                                       destination: Destination::BlindedPath(path.clone()),
-                                       reply_path: Some(reply_path.clone()),
-                               };
+                               let message = new_pending_onion_message(
+                                       OffersMessage::InvoiceRequest(invoice_request.clone()),
+                                       Destination::BlindedPath(path.clone()),
+                                       Some(reply_path.clone()),
+                               );
                                pending_offers_messages.push(message);
                        }
                }
@@ -7454,6 +7547,13 @@ where
        /// [`BlindedPath`] containing the [`PaymentSecret`] needed to reconstruct the corresponding
        /// [`PaymentPreimage`].
        ///
+       /// # Limitations
+       ///
+       /// Requires a direct connection to an introduction node in [`Refund::paths`] or to
+       /// [`Refund::payer_id`], if empty. This request is best effort; an invoice will be sent to each
+       /// node meeting the aforementioned criteria, but there's no guarantee that they will be
+       /// received and no retries will be made.
+       ///
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn request_refund_payment(&self, refund: &Refund) -> Result<(), Bolt12SemanticError> {
                let expanded_key = &self.inbound_payment_key;
@@ -7485,19 +7585,19 @@ where
 
                                let mut pending_offers_messages = self.pending_offers_messages.lock().unwrap();
                                if refund.paths().is_empty() {
-                                       let message = PendingOnionMessage {
-                                               contents: OffersMessage::Invoice(invoice),
-                                               destination: Destination::Node(refund.payer_id()),
-                                               reply_path: Some(reply_path),
-                                       };
+                                       let message = new_pending_onion_message(
+                                               OffersMessage::Invoice(invoice),
+                                               Destination::Node(refund.payer_id()),
+                                               Some(reply_path),
+                                       );
                                        pending_offers_messages.push(message);
                                } else {
                                        for path in refund.paths() {
-                                               let message = PendingOnionMessage {
-                                                       contents: OffersMessage::Invoice(invoice.clone()),
-                                                       destination: Destination::BlindedPath(path.clone()),
-                                                       reply_path: Some(reply_path.clone()),
-                                               };
+                                               let message = new_pending_onion_message(
+                                                       OffersMessage::Invoice(invoice.clone()),
+                                                       Destination::BlindedPath(path.clone()),
+                                                       Some(reply_path.clone()),
+                                               );
                                                pending_offers_messages.push(message);
                                        }
                                }
@@ -8244,13 +8344,13 @@ where
                self.best_block.read().unwrap().clone()
        }
 
-       /// Fetches the set of [`NodeFeatures`] flags which are provided by or required by
+       /// Fetches the set of [`NodeFeatures`] flags that are provided by or required by
        /// [`ChannelManager`].
        pub fn node_features(&self) -> NodeFeatures {
                provided_node_features(&self.default_configuration)
        }
 
-       /// Fetches the set of [`Bolt11InvoiceFeatures`] flags which are provided by or required by
+       /// Fetches the set of [`Bolt11InvoiceFeatures`] flags that are provided by or required by
        /// [`ChannelManager`].
        ///
        /// Note that the invoice feature flags can vary depending on if the invoice is a "phantom invoice"
@@ -8260,19 +8360,25 @@ where
                provided_bolt11_invoice_features(&self.default_configuration)
        }
 
-       /// Fetches the set of [`ChannelFeatures`] flags which are provided by or required by
+       /// Fetches the set of [`Bolt12InvoiceFeatures`] flags that are provided by or required by
+       /// [`ChannelManager`].
+       fn bolt12_invoice_features(&self) -> Bolt12InvoiceFeatures {
+               provided_bolt12_invoice_features(&self.default_configuration)
+       }
+
+       /// Fetches the set of [`ChannelFeatures`] flags that are provided by or required by
        /// [`ChannelManager`].
        pub fn channel_features(&self) -> ChannelFeatures {
                provided_channel_features(&self.default_configuration)
        }
 
-       /// Fetches the set of [`ChannelTypeFeatures`] flags which are provided by or required by
+       /// Fetches the set of [`ChannelTypeFeatures`] flags that are provided by or required by
        /// [`ChannelManager`].
        pub fn channel_type_features(&self) -> ChannelTypeFeatures {
                provided_channel_type_features(&self.default_configuration)
        }
 
-       /// Fetches the set of [`InitFeatures`] flags which are provided by or required by
+       /// Fetches the set of [`InitFeatures`] flags that are provided by or required by
        /// [`ChannelManager`].
        pub fn init_features(&self) -> InitFeatures {
                provided_init_features(&self.default_configuration)
@@ -8803,7 +8909,128 @@ where
        }
 }
 
-/// Fetches the set of [`NodeFeatures`] flags which are provided by or required by
+impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>
+OffersMessageHandler for ChannelManager<M, T, ES, NS, SP, F, R, L>
+where
+       M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
+       T::Target: BroadcasterInterface,
+       ES::Target: EntropySource,
+       NS::Target: NodeSigner,
+       SP::Target: SignerProvider,
+       F::Target: FeeEstimator,
+       R::Target: Router,
+       L::Target: Logger,
+{
+       fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage> {
+               let secp_ctx = &self.secp_ctx;
+               let expanded_key = &self.inbound_payment_key;
+
+               match message {
+                       OffersMessage::InvoiceRequest(invoice_request) => {
+                               let amount_msats = match InvoiceBuilder::<DerivedSigningPubkey>::amount_msats(
+                                       &invoice_request
+                               ) {
+                                       Ok(amount_msats) => Some(amount_msats),
+                                       Err(error) => return Some(OffersMessage::InvoiceError(error.into())),
+                               };
+                               let invoice_request = match invoice_request.verify(expanded_key, secp_ctx) {
+                                       Ok(invoice_request) => invoice_request,
+                                       Err(()) => {
+                                               let error = Bolt12SemanticError::InvalidMetadata;
+                                               return Some(OffersMessage::InvoiceError(error.into()));
+                                       },
+                               };
+                               let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32;
+
+                               match self.create_inbound_payment(amount_msats, relative_expiry, None) {
+                                       Ok((payment_hash, payment_secret)) if invoice_request.keys.is_some() => {
+                                               let payment_paths = vec![
+                                                       self.create_one_hop_blinded_payment_path(payment_secret),
+                                               ];
+                                               #[cfg(not(feature = "no-std"))]
+                                               let builder = invoice_request.respond_using_derived_keys(
+                                                       payment_paths, payment_hash
+                                               );
+                                               #[cfg(feature = "no-std")]
+                                               let created_at = Duration::from_secs(
+                                                       self.highest_seen_timestamp.load(Ordering::Acquire) as u64
+                                               );
+                                               #[cfg(feature = "no-std")]
+                                               let builder = invoice_request.respond_using_derived_keys_no_std(
+                                                       payment_paths, payment_hash, created_at
+                                               );
+                                               match builder.and_then(|b| b.allow_mpp().build_and_sign(secp_ctx)) {
+                                                       Ok(invoice) => Some(OffersMessage::Invoice(invoice)),
+                                                       Err(error) => Some(OffersMessage::InvoiceError(error.into())),
+                                               }
+                                       },
+                                       Ok((payment_hash, payment_secret)) => {
+                                               let payment_paths = vec![
+                                                       self.create_one_hop_blinded_payment_path(payment_secret),
+                                               ];
+                                               #[cfg(not(feature = "no-std"))]
+                                               let builder = invoice_request.respond_with(payment_paths, payment_hash);
+                                               #[cfg(feature = "no-std")]
+                                               let created_at = Duration::from_secs(
+                                                       self.highest_seen_timestamp.load(Ordering::Acquire) as u64
+                                               );
+                                               #[cfg(feature = "no-std")]
+                                               let builder = invoice_request.respond_with_no_std(
+                                                       payment_paths, payment_hash, created_at
+                                               );
+                                               let response = builder.and_then(|builder| builder.allow_mpp().build())
+                                                       .map_err(|e| OffersMessage::InvoiceError(e.into()))
+                                                       .and_then(|invoice|
+                                                               match invoice.sign(|invoice| self.node_signer.sign_bolt12_invoice(invoice)) {
+                                                                       Ok(invoice) => Ok(OffersMessage::Invoice(invoice)),
+                                                                       Err(SignError::Signing(())) => Err(OffersMessage::InvoiceError(
+                                                                                       InvoiceError::from_string("Failed signing invoice".to_string())
+                                                                       )),
+                                                                       Err(SignError::Verification(_)) => Err(OffersMessage::InvoiceError(
+                                                                                       InvoiceError::from_string("Failed invoice signature verification".to_string())
+                                                                       )),
+                                                               });
+                                               match response {
+                                                       Ok(invoice) => Some(invoice),
+                                                       Err(error) => Some(error),
+                                               }
+                                       },
+                                       Err(()) => {
+                                               Some(OffersMessage::InvoiceError(Bolt12SemanticError::InvalidAmount.into()))
+                                       },
+                               }
+                       },
+                       OffersMessage::Invoice(invoice) => {
+                               match invoice.verify(expanded_key, secp_ctx) {
+                                       Err(()) => {
+                                               Some(OffersMessage::InvoiceError(InvoiceError::from_string("Unrecognized invoice".to_owned())))
+                                       },
+                                       Ok(_) if invoice.invoice_features().requires_unknown_bits_from(&self.bolt12_invoice_features()) => {
+                                               Some(OffersMessage::InvoiceError(Bolt12SemanticError::UnknownRequiredFeatures.into()))
+                                       },
+                                       Ok(payment_id) => {
+                                               if let Err(e) = self.send_payment_for_bolt12_invoice(&invoice, payment_id) {
+                                                       log_trace!(self.logger, "Failed paying invoice: {:?}", e);
+                                                       Some(OffersMessage::InvoiceError(InvoiceError::from_string(format!("{:?}", e))))
+                                               } else {
+                                                       None
+                                               }
+                                       },
+                               }
+                       },
+                       OffersMessage::InvoiceError(invoice_error) => {
+                               log_trace!(self.logger, "Received invoice_error: {}", invoice_error);
+                               None
+                       },
+               }
+       }
+
+       fn release_pending_messages(&self) -> Vec<PendingOnionMessage<OffersMessage>> {
+               core::mem::take(&mut self.pending_offers_messages.lock().unwrap())
+       }
+}
+
+/// Fetches the set of [`NodeFeatures`] flags that are provided by or required by
 /// [`ChannelManager`].
 pub(crate) fn provided_node_features(config: &UserConfig) -> NodeFeatures {
        let mut node_features = provided_init_features(config).to_context();
@@ -8811,7 +9038,7 @@ pub(crate) fn provided_node_features(config: &UserConfig) -> NodeFeatures {
        node_features
 }
 
-/// Fetches the set of [`Bolt11InvoiceFeatures`] flags which are provided by or required by
+/// Fetches the set of [`Bolt11InvoiceFeatures`] flags that are provided by or required by
 /// [`ChannelManager`].
 ///
 /// Note that the invoice feature flags can vary depending on if the invoice is a "phantom invoice"
@@ -8821,19 +9048,25 @@ pub(crate) fn provided_bolt11_invoice_features(config: &UserConfig) -> Bolt11Inv
        provided_init_features(config).to_context()
 }
 
-/// Fetches the set of [`ChannelFeatures`] flags which are provided by or required by
+/// Fetches the set of [`Bolt12InvoiceFeatures`] flags that are provided by or required by
+/// [`ChannelManager`].
+pub(crate) fn provided_bolt12_invoice_features(config: &UserConfig) -> Bolt12InvoiceFeatures {
+       provided_init_features(config).to_context()
+}
+
+/// Fetches the set of [`ChannelFeatures`] flags that are provided by or required by
 /// [`ChannelManager`].
 pub(crate) fn provided_channel_features(config: &UserConfig) -> ChannelFeatures {
        provided_init_features(config).to_context()
 }
 
-/// Fetches the set of [`ChannelTypeFeatures`] flags which are provided by or required by
+/// Fetches the set of [`ChannelTypeFeatures`] flags that are provided by or required by
 /// [`ChannelManager`].
 pub(crate) fn provided_channel_type_features(config: &UserConfig) -> ChannelTypeFeatures {
        ChannelTypeFeatures::from_init(&provided_init_features(config))
 }
 
-/// Fetches the set of [`InitFeatures`] flags which are provided by or required by
+/// Fetches the set of [`InitFeatures`] flags that are provided by or required by
 /// [`ChannelManager`].
 pub fn provided_init_features(config: &UserConfig) -> InitFeatures {
        // Note that if new features are added here which other peers may (eventually) require, we