Add currency conversion support for BOLT 12 offers

fuzz/src/full_stack.rs

@@ -51,7 +51,9 @@ use lightning::ln::peer_handler::{
 };
 use lightning::ln::script::ShutdownScript;
 use lightning::ln::types::ChannelId;
+use lightning::offers::currency::CurrencyConversion;
 use lightning::offers::invoice::UnsignedBolt12Invoice;
+use lightning::offers::offer::CurrencyCode;
 use lightning::onion_message::messenger::{Destination, MessageRouter, OnionMessagePath};
 use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
 use lightning::routing::router::{
@@ -184,6 +186,14 @@ impl MessageRouter for FuzzRouter {
 	}
 }
 
+struct FuzzCurrencyConversion;
+
+impl CurrencyConversion for FuzzCurrencyConversion {
+	fn msats_per_minor_unit(&self, _iso4217_code: CurrencyCode) -> Result<(f64, u8), ()> {
+		Err(())
+	}
+}
+
 struct TestBroadcaster {
 	txn_broadcasted: Mutex<Vec<Transaction>>,
 }
@@ -239,6 +249,7 @@ type ChannelMan<'a> = ChannelManager<
 	Arc<FuzzEstimator>,
 	&'a FuzzRouter,
 	&'a FuzzRouter,
+	&'a FuzzCurrencyConversion,
 	Arc<dyn Logger + MaybeSend + MaybeSync>,
 >;
 type PeerMan<'a> = PeerManager<
@@ -549,6 +560,8 @@ pub fn do_test(mut data: &[u8], logger: &Arc<dyn Logger + MaybeSend + MaybeSync>
 	let fee_est = Arc::new(FuzzEstimator { input: input.clone() });
 	let router = FuzzRouter {};
 
+	let conversion = FuzzCurrencyConversion;
+
 	macro_rules! get_slice {
 		($len: expr) => {
 			match input.get_slice($len as usize) {
@@ -613,6 +626,7 @@ pub fn do_test(mut data: &[u8], logger: &Arc<dyn Logger + MaybeSend + MaybeSync>
 		broadcast.clone(),
 		&router,
 		&router,
+		&conversion,
 		Arc::clone(&logger),
 		keys_manager.clone(),
 		keys_manager.clone(),

fuzz/src/invoice_request_deser.rs

@@ -16,9 +16,10 @@ use lightning::blinded_path::payment::{
 };
 use lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY_DELTA;
 use lightning::ln::inbound_payment::ExpandedKey;
+use lightning::offers::currency::CurrencyConversion;
 use lightning::offers::invoice::UnsignedBolt12Invoice;
 use lightning::offers::invoice_request::{InvoiceRequest, InvoiceRequestFields};
-use lightning::offers::offer::OfferId;
+use lightning::offers::offer::{CurrencyCode, OfferId};
 use lightning::offers::parse::Bolt12SemanticError;
 use lightning::sign::{EntropySource, ReceiveAuthKey};
 use lightning::types::features::BlindedHopFeatures;
@@ -61,6 +62,14 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], _out: Out) {
 	}
 }
 
+struct FuzzCurrencyConversion;
+
+impl CurrencyConversion for FuzzCurrencyConversion {
+	fn msats_per_minor_unit(&self, _iso4217_code: CurrencyCode) -> Result<(f64, u8), ()> {
+		Err(())
+	}
+}
+
 struct Randomness;
 
 impl EntropySource for Randomness {
@@ -144,7 +153,10 @@ fn build_response<T: secp256k1::Signing + secp256k1::Verification>(
 	.unwrap();
 
 	let payment_hash = PaymentHash([42; 32]);
-	invoice_request.respond_with(vec![payment_path], payment_hash)?.build()
+	let conversion = FuzzCurrencyConversion;
+	invoice_request
+		.respond_with(&conversion, vec![payment_path], payment_hash)?
+		.build()
 }
 
 pub fn invoice_request_deser_test<Out: test_logger::Output>(data: &[u8], out: Out) {

fuzz/src/offer_deser.rs

@@ -12,9 +12,10 @@ use bitcoin::secp256k1::Secp256k1;
 use core::convert::TryFrom;
 use lightning::ln::channelmanager::PaymentId;
 use lightning::ln::inbound_payment::ExpandedKey;
+use lightning::offers::currency::DefaultCurrencyConversion;
 use lightning::offers::invoice_request::InvoiceRequest;
 use lightning::offers::nonce::Nonce;
-use lightning::offers::offer::{Amount, Offer, Quantity};
+use lightning::offers::offer::{Offer, Quantity};
 use lightning::offers::parse::Bolt12SemanticError;
 use lightning::sign::EntropySource;
 use lightning::util::ser::Writeable;
@@ -48,13 +49,13 @@ fn build_request(offer: &Offer) -> Result<InvoiceRequest, Bolt12SemanticError> {
 	let nonce = Nonce::from_entropy_source(&entropy);
 	let secp_ctx = Secp256k1::new();
 	let payment_id = PaymentId([1; 32]);
+	let conversion = DefaultCurrencyConversion;
 
-	let mut builder = offer.request_invoice(&expanded_key, nonce, &secp_ctx, payment_id)?;
+	let mut builder = offer.request_invoice(&expanded_key, nonce, &secp_ctx, payment_id, &conversion)?;
 
 	builder = match offer.amount() {
 		None => builder.amount_msats(1000).unwrap(),
-		Some(Amount::Bitcoin { amount_msats }) => builder.amount_msats(amount_msats + 1)?,
-		Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
+		Some(amount) => builder.amount_msats(amount.into_msats(&conversion)?)?,
 	};
 
 	builder = match offer.supported_quantity() {

lightning-background-processor/src/lib.rs

@@ -378,6 +378,9 @@ type DynMessageRouter = lightning::onion_message::messenger::DefaultMessageRoute
 	&'static (dyn EntropySource + Send + Sync),
 >;
 
+#[cfg(not(c_bindings))]
+type DynCurrencyConversion = lightning::offers::currency::DefaultCurrencyConversion;
+
 #[cfg(not(c_bindings))]
 type DynSignerProvider = dyn lightning::sign::SignerProvider<EcdsaSigner = lightning::sign::InMemorySigner>
 	+ Send
@@ -393,6 +396,7 @@ type DynChannelManager = lightning::ln::channelmanager::ChannelManager<
 	&'static (dyn FeeEstimator + Send + Sync),
 	&'static DynRouter,
 	&'static DynMessageRouter,
+	&'static DynCurrencyConversion,
 	&'static (dyn Logger + Send + Sync),
 >;
 
@@ -1949,6 +1953,7 @@ mod tests {
 		IgnoringMessageHandler, MessageHandler, PeerManager, SocketDescriptor,
 	};
 	use lightning::ln::types::ChannelId;
+	use lightning::offers::currency::DefaultCurrencyConversion;
 	use lightning::onion_message::messenger::{DefaultMessageRouter, OnionMessenger};
 	use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
 	use lightning::routing::router::{CandidateRouteHop, DefaultRouter, Path, RouteHop};
@@ -2044,6 +2049,7 @@ mod tests {
 				Arc<KeysManager>,
 			>,
 		>,
+		Arc<DefaultCurrencyConversion>,
 		Arc<test_utils::TestLogger>,
 	>;
 
@@ -2468,6 +2474,7 @@ mod tests {
 				Arc::clone(&network_graph),
 				Arc::clone(&keys_manager),
 			));
+			let conversion = Arc::new(DefaultCurrencyConversion);
 			let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Bitcoin));
 			let kv_store =
 				Arc::new(Persister::new(format!("{}_persister_{}", &persist_dir, i).into()));
@@ -2494,6 +2501,7 @@ mod tests {
 				Arc::clone(&tx_broadcaster),
 				Arc::clone(&router),
 				Arc::clone(&msg_router),
+				Arc::clone(&conversion),
 				Arc::clone(&logger),
 				Arc::clone(&keys_manager),
 				Arc::clone(&keys_manager),

lightning-block-sync/src/init.rs

@@ -53,6 +53,7 @@ where
 /// use lightning::chain::chaininterface::BroadcasterInterface;
 /// use lightning::chain::chaininterface::FeeEstimator;
 /// use lightning::ln::channelmanager::{ChannelManager, ChannelManagerReadArgs};
+/// use lightning::offers::currency::CurrencyConversion;
 /// use lightning::onion_message::messenger::MessageRouter;
 /// use lightning::routing::router::Router;
 /// use lightning::sign;
@@ -74,6 +75,7 @@ where
 /// 	F: FeeEstimator,
 /// 	R: Router,
 /// 	MR: MessageRouter,
+/// 	CC: CurrencyConversion,
 /// 	L: Logger,
 /// 	C: chain::Filter,
 /// 	P: chainmonitor::Persist<SP::EcdsaSigner>,
@@ -88,6 +90,7 @@ where
 /// 	fee_estimator: &F,
 /// 	router: &R,
 /// 	message_router: &MR,
+/// 	currency_conversion: &CC,
 /// 	logger: &L,
 /// 	persister: &P,
 /// ) {
@@ -108,11 +111,12 @@ where
 /// 			tx_broadcaster,
 /// 			router,
 /// 			message_router,
+/// 			currency_conversion,
 /// 			logger,
 /// 			config,
 /// 			vec![&mut monitor],
 /// 		);
-/// 		<(BestBlock, ChannelManager<&ChainMonitor<SP::EcdsaSigner, &C, &T, &F, &L, &P, &ES>, &T, &ES, &NS, &SP, &F, &R, &MR, &L>)>::read(
+/// 		<(BestBlock, ChannelManager<&ChainMonitor<SP::EcdsaSigner, &C, &T, &F, &L, &P, &ES>, &T, &ES, &NS, &SP, &F, &R, &MR, &CC, &L>)>::read(
 /// 			&mut Cursor::new(&serialized_manager), read_args).unwrap()
 /// 	};
 ///

lightning/src/ln/async_payments_tests.rs

@@ -299,6 +299,7 @@ fn create_static_invoice_builder<'a>(
 			relative_expiry_secs,
 			recipient.node.list_usable_channels(),
 			recipient.node.test_get_peers_for_blinded_path(),
+			recipient.node.currency_conversion,
 		)
 		.unwrap()
 }
@@ -324,7 +325,7 @@ fn create_static_invoice<T: secp256k1::Signing + secp256k1::Verification>(
 		.flow
 		.create_async_receive_offer_builder(entropy_source, blinded_paths_to_always_online_node)
 		.unwrap();
-	let offer = offer_builder.build().unwrap();
+	let offer = offer_builder.build();
 	let static_invoice =
 		create_static_invoice_builder(recipient, &offer, offer_nonce, relative_expiry)
 			.build_and_sign(&secp_ctx)
@@ -695,7 +696,7 @@ fn static_invoice_unknown_required_features() {
 		.flow
 		.create_async_receive_offer_builder(entropy_source, blinded_paths_to_always_online_node)
 		.unwrap();
-	let offer = offer_builder.build().unwrap();
+	let offer = offer_builder.build();
 	let static_invoice_unknown_req_features =
 		create_static_invoice_builder(&nodes[2], &offer, nonce, None)
 			.features_unchecked(Bolt12InvoiceFeatures::unknown())
@@ -1478,6 +1479,7 @@ fn amount_doesnt_match_invreq() {
 					Nonce::from_entropy_source(nodes[0].keys_manager),
 					&secp_ctx,
 					payment_id,
+					nodes[0].node.currency_conversion,
 				)
 				.unwrap()
 				.amount_msats(amt_msat + 1)
@@ -1679,7 +1681,7 @@ fn invalid_async_receive_with_retry<F1, F2>(
 		.flow
 		.create_async_receive_offer_builder(entropy_source, blinded_paths_to_always_online_node)
 		.unwrap();
-	let offer = offer_builder.build().unwrap();
+	let offer = offer_builder.build();
 	let amt_msat = 5000;
 	let payment_id = PaymentId([1; 32]);