Organize create_refund and pay_for_offer docs
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 2df3b5d416376cdeed5c62ba26a40b92f6b530a2..d28270db5bb6b49542434064cdd8cbcc8dce6c83 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};
 use crate::sign::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, WriteableEcdsaChannelSigner};
 use crate::util::config::{UserConfig, ChannelConfig, ChannelConfigUpdate};
 use crate::util::wakers::{Future, Notifier};
@@ -3579,6 +3581,17 @@ 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 +3606,20 @@ 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);
@@ -7295,6 +7318,8 @@ 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
@@ -7319,19 +7344,32 @@ 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`].
+       ///
+       /// # 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
        /// node must be announced. Otherwise, there is no way to find a path to the introduction node
        /// in order to send the [`Bolt12Invoice`].
        ///
+       /// # Errors
+       ///
+       /// Errors if a duplicate `payment_id` is provided given the caveats in the aforementioned link
+       /// or if `amount_msats` is invalid.
+       ///
        /// [`Refund`]: crate::offers::refund::Refund
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn create_refund_builder(
@@ -7373,12 +7411,20 @@ where
        /// - `amount_msats` if overpaying what is required for the given `quantity` is desired, and
        /// - `payer_note` for [`InvoiceRequest::payer_note`].
        ///
+       /// # 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.
+       /// # 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
@@ -8244,35 +8290,41 @@ 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"
        /// or not. Thus, this method is not public.
        #[cfg(any(feature = "_test_utils", test))]
-       pub fn invoice_features(&self) -> Bolt11InvoiceFeatures {
-               provided_invoice_features(&self.default_configuration)
+       pub fn bolt11_invoice_features(&self) -> Bolt11InvoiceFeatures {
+               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 +8855,128 @@ 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_str("Failed signing invoice")
+                                                                       )),
+                                                                       Err(SignError::Verification(_)) => Err(OffersMessage::InvoiceError(
+                                                                                       InvoiceError::from_str("Failed invoice signature verification")
+                                                                       )),
+                                                               });
+                                               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_str("Unrecognized invoice")))
+                                       },
+                                       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_str(&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();
@@ -8811,29 +8984,35 @@ 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"
 /// or not. Thus, this method is not public.
 #[cfg(any(feature = "_test_utils", test))]
-pub(crate) fn provided_invoice_features(config: &UserConfig) -> Bolt11InvoiceFeatures {
+pub(crate) fn provided_bolt11_invoice_features(config: &UserConfig) -> Bolt11InvoiceFeatures {
+       provided_init_features(config).to_context()
+}
+
+/// 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 which are provided by or required by
+/// 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
@@ -11988,7 +12167,7 @@ pub mod bench {
                macro_rules! send_payment {
                        ($node_a: expr, $node_b: expr) => {
                                let payment_params = PaymentParameters::from_node_id($node_b.get_our_node_id(), TEST_FINAL_CLTV)
-                                       .with_bolt11_features($node_b.invoice_features()).unwrap();
+                                       .with_bolt11_features($node_b.bolt11_invoice_features()).unwrap();
                                let mut payment_preimage = PaymentPreimage([0; 32]);
                                payment_preimage.0[0..8].copy_from_slice(&payment_count.to_le_bytes());
                                payment_count += 1;