Merge pull request #3010 from shaavan/issue2836

Introduce Retry InvoiceRequest Flow

lightning-net-tokio/src/lib.rs

@@ -786,6 +786,7 @@ mod tests {
 		fn get_chain_hashes(&self) -> Option<Vec<ChainHash>> {
 			Some(vec![ChainHash::using_genesis_block(Network::Testnet)])
 		}
+		fn message_received(&self) {}
 	}
 	impl MessageSendEventsProvider for MsgHandler {
 		fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {

lightning/src/ln/channelmanager.rs

@@ -61,11 +61,11 @@ use crate::ln::onion_utils::{HTLCFailReason, INVALID_ONION_BLINDING};
 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::{OutboundPayments, PaymentAttempts, PendingOutboundPayment, RetryableInvoiceRequest, SendAlongPathArgs, StaleExpiration};
 use crate::ln::wire::Encode;
 use crate::offers::invoice::{Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder, UnsignedBolt12Invoice};
 use crate::offers::invoice_error::InvoiceError;
-use crate::offers::invoice_request::{DerivedPayerId, InvoiceRequestBuilder};
+use crate::offers::invoice_request::{DerivedPayerId, InvoiceRequest, InvoiceRequestBuilder};
 use crate::offers::nonce::Nonce;
 use crate::offers::offer::{Offer, OfferBuilder};
 use crate::offers::parse::Bolt12SemanticError;
@@ -3105,7 +3105,7 @@ where
 
 			outbound_scid_aliases: Mutex::new(new_hash_set()),
 			pending_inbound_payments: Mutex::new(new_hash_map()),
-			pending_outbound_payments: OutboundPayments::new(),
+			pending_outbound_payments: OutboundPayments::new(new_hash_map()),
 			forward_htlcs: Mutex::new(new_hash_map()),
 			decode_update_add_htlcs: Mutex::new(new_hash_map()),
 			claimable_payments: Mutex::new(ClaimablePayments { claimable_payments: new_hash_map(), pending_claiming_payments: new_hash_map() }),
@@ -9005,7 +9005,7 @@ macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
 		let expiration = StaleExpiration::AbsoluteTimeout(absolute_expiry);
 		$self.pending_outbound_payments
 			.add_new_awaiting_invoice(
-				payment_id, expiration, retry_strategy, max_total_routing_fee_msat,
+				payment_id, expiration, retry_strategy, max_total_routing_fee_msat, None,
 			)
 			.map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
 
@@ -9131,17 +9131,30 @@ where
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
 
 		let expiration = StaleExpiration::TimerTicks(1);
+		let retryable_invoice_request = RetryableInvoiceRequest {
+			invoice_request: invoice_request.clone(),
+			nonce,
+		};
 		self.pending_outbound_payments
 			.add_new_awaiting_invoice(
-				payment_id, expiration, retry_strategy, max_total_routing_fee_msat
+				payment_id, expiration, retry_strategy, max_total_routing_fee_msat,
+				Some(retryable_invoice_request)
 			)
 			.map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
 
+		self.enqueue_invoice_request(invoice_request, reply_paths)
+	}
+
+	fn enqueue_invoice_request(
+		&self,
+		invoice_request: InvoiceRequest,
+		reply_paths: Vec<BlindedMessagePath>,
+	) -> Result<(), Bolt12SemanticError> {
 		let mut pending_offers_messages = self.pending_offers_messages.lock().unwrap();
-		if !offer.paths().is_empty() {
+		if !invoice_request.paths().is_empty() {
 			reply_paths
 				.iter()
-				.flat_map(|reply_path| offer.paths().iter().map(move |path| (path, reply_path)))
+				.flat_map(|reply_path| invoice_request.paths().iter().map(move |path| (path, reply_path)))
 				.take(OFFERS_MESSAGE_REQUEST_LIMIT)
 				.for_each(|(path, reply_path)| {
 					let instructions = MessageSendInstructions::WithSpecifiedReplyPath {
@@ -9151,7 +9164,7 @@ where
 					let message = OffersMessage::InvoiceRequest(invoice_request.clone());
 					pending_offers_messages.push((message, instructions));
 				});
-		} else if let Some(signing_pubkey) = offer.signing_pubkey() {
+		} else if let Some(signing_pubkey) = invoice_request.signing_pubkey() {
 			for reply_path in reply_paths {
 				let instructions = MessageSendInstructions::WithSpecifiedReplyPath {
 					destination: Destination::Node(signing_pubkey),
@@ -10811,6 +10824,39 @@ where
 			"Dual-funded channels not supported".to_owned(),
 			msg.channel_id.clone())), counterparty_node_id);
 	}
+
+	fn message_received(&self) {
+		for (payment_id, retryable_invoice_request) in self
+			.pending_outbound_payments
+			.release_invoice_requests_awaiting_invoice()
+		{
+			let RetryableInvoiceRequest { invoice_request, nonce } = retryable_invoice_request;
+			let hmac = payment_id.hmac_for_offer_payment(nonce, &self.inbound_payment_key);
+			let context = OffersContext::OutboundPayment {
+				payment_id,
+				nonce,
+				hmac: Some(hmac)
+			};
+			match self.create_blinded_paths(context) {
+				Ok(reply_paths) => match self.enqueue_invoice_request(invoice_request, reply_paths) {
+					Ok(_) => {}
+					Err(_) => {
+						log_warn!(self.logger,
+							"Retry failed for an invoice request with payment_id: {}",
+							payment_id
+						);
+					}
+				},
+				Err(_) => {
+					log_warn!(self.logger,
+						"Retry failed for an invoice request with payment_id: {}. \
+							Reason: router could not find a blinded path to include as the reply path",
+						payment_id
+					);
+				}
+			}
+		}
+	}
 }
 
 impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>
@@ -12227,10 +12273,7 @@ where
 			}
 			pending_outbound_payments = Some(outbounds);
 		}
-		let pending_outbounds = OutboundPayments {
-			pending_outbound_payments: Mutex::new(pending_outbound_payments.unwrap()),
-			retry_lock: Mutex::new(())
-		};
+		let pending_outbounds = OutboundPayments::new(pending_outbound_payments.unwrap());
 
 		// We have to replay (or skip, if they were completed after we wrote the `ChannelManager`)
 		// each `ChannelMonitorUpdate` in `in_flight_monitor_updates`. After doing so, we have to

lightning/src/ln/msgs.rs

@@ -1605,6 +1605,14 @@ pub trait ChannelMessageHandler : MessageSendEventsProvider {
 	/// If it's `None`, then no particular network chain hash compatibility will be enforced when
 	/// connecting to peers.
 	fn get_chain_hashes(&self) -> Option<Vec<ChainHash>>;
+
+	/// Indicates that a message was received from any peer for any handler.
+	/// Called before the message is passed to the appropriate handler.
+	/// Useful for indicating that a network connection is active.
+	///
+	/// Note: Since this function is called frequently, it should be as
+	/// efficient as possible for its intended purpose.
+	fn message_received(&self);
 }
 
 /// A trait to describe an object which can receive routing messages.

lightning/src/ln/offers_tests.rs

@@ -1070,6 +1070,78 @@ fn send_invoice_for_refund_with_distinct_reply_path() {
 	assert_eq!(reply_path.introduction_node(), &IntroductionNode::NodeId(nodes[6].node.get_our_node_id()));
 }
 
+/// Verifies that the invoice request message can be retried if it fails to reach the
+/// payee on the first attempt.
+#[test]
+fn creates_and_pays_for_offer_with_retry() {
+	let chanmon_cfgs = create_chanmon_cfgs(2);
+	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 10_000_000, 1_000_000_000);
+
+	let alice = &nodes[0];
+	let alice_id = alice.node.get_our_node_id();
+	let bob = &nodes[1];
+	let bob_id = bob.node.get_our_node_id();
+
+	let offer = alice.node
+		.create_offer_builder(None).unwrap()
+		.amount_msats(10_000_000)
+		.build().unwrap();
+	assert_ne!(offer.signing_pubkey(), Some(alice_id));
+	assert!(!offer.paths().is_empty());
+	for path in offer.paths() {
+		assert_eq!(path.introduction_node(), &IntroductionNode::NodeId(alice_id));
+	}
+	let payment_id = PaymentId([1; 32]);
+	bob.node.pay_for_offer(&offer, None, None, None, payment_id, Retry::Attempts(0), None).unwrap();
+	expect_recent_payment!(bob, RecentPaymentDetails::AwaitingInvoice, payment_id);
+
+	let _lost_onion_message = bob.onion_messenger.next_onion_message_for_peer(alice_id).unwrap();
+
+	// Simulate a scenario where the original onion_message is lost before reaching Alice.
+	// Use handle_message_received to regenerate the message.
+	bob.node.message_received();
+	let onion_message = bob.onion_messenger.next_onion_message_for_peer(alice_id).unwrap();
+
+	alice.onion_messenger.handle_onion_message(bob_id, &onion_message);
+
+	let (invoice_request, reply_path) = extract_invoice_request(alice, &onion_message);
+	let payment_context = PaymentContext::Bolt12Offer(Bolt12OfferContext {
+		offer_id: offer.id(),
+		invoice_request: InvoiceRequestFields {
+			payer_id: invoice_request.payer_id(),
+			quantity: None,
+			payer_note_truncated: None,
+		},
+	});
+	assert_eq!(invoice_request.amount_msats(), None);
+	assert_ne!(invoice_request.payer_id(), bob_id);
+	assert_eq!(reply_path.introduction_node(), &IntroductionNode::NodeId(bob_id));
+	let onion_message = alice.onion_messenger.next_onion_message_for_peer(bob_id).unwrap();
+	bob.onion_messenger.handle_onion_message(alice_id, &onion_message);
+
+	// Expect no more OffersMessage to be enqueued by this point, even after calling
+	// handle_message_received.
+	bob.node.message_received();
+
+	assert!(bob.onion_messenger.next_onion_message_for_peer(alice_id).is_none());
+
+	let (invoice, _) = extract_invoice(bob, &onion_message);
+	assert_eq!(invoice.amount_msats(), 10_000_000);
+	assert_ne!(invoice.signing_pubkey(), alice_id);
+	assert!(!invoice.payment_paths().is_empty());
+	for path in invoice.payment_paths() {
+		assert_eq!(path.introduction_node(), &IntroductionNode::NodeId(alice_id));
+	}
+	route_bolt12_payment(bob, &[alice], &invoice);
+	expect_recent_payment!(bob, RecentPaymentDetails::Pending, payment_id);
+	claim_bolt12_payment(bob, &[alice], payment_context);
+	expect_recent_payment!(bob, RecentPaymentDetails::Fulfilled, payment_id);
+}
+
 /// Checks that a deferred invoice can be paid asynchronously from an Event::InvoiceReceived.
 #[test]
 fn pays_bolt12_invoice_asynchronously() {