Add payer_note in PaymentKind::Bolt12

Add support for including `payer_note` in `Bolt12Offer`
and `PaymentKind::Bolt12` and updated the relevant code to
handle where the new `payer_note` field was required.

Author: slanesuke

bindings/ldk_node.udl

@@ -120,17 +120,17 @@ interface Bolt11Payment {
 
 interface Bolt12Payment {
 	[Throws=NodeError]
-	PaymentId send([ByRef]Offer offer, string? payer_note);
+	PaymentId send([ByRef]Offer offer, u64? quantity, string? payer_note);
 	[Throws=NodeError]
-	PaymentId send_using_amount([ByRef]Offer offer, string? payer_note, u64 amount_msat);
+	PaymentId send_using_amount([ByRef]Offer offer, u64 amount_msat, u64? quantity, string? payer_note);
 	[Throws=NodeError]
-	Offer receive(u64 amount_msat, [ByRef]string description);
+	Offer receive(u64 amount_msat, [ByRef]string description, u64? quantity);
 	[Throws=NodeError]
 	Offer receive_variable_amount([ByRef]string description);
 	[Throws=NodeError]
 	Bolt12Invoice request_refund_payment([ByRef]Refund refund);
 	[Throws=NodeError]
-	Refund initiate_refund(u64 amount_msat, u32 expiry_secs);
+	Refund initiate_refund(u64 amount_msat, u32 expiry_secs, u64? quantity, string? payer_note);
 };
 
 interface SpontaneousPayment {
@@ -201,6 +201,7 @@ enum NodeError {
 	"InvalidChannelId",
 	"InvalidNetwork",
 	"InvalidUri",
+	"InvalidQuantity",
 	"DuplicatePayment",
 	"UnsupportedCurrency",
 	"InsufficientFunds",
@@ -281,8 +282,8 @@ interface PaymentKind {
 	Onchain();
 	Bolt11(PaymentHash hash, PaymentPreimage? preimage, PaymentSecret? secret);
 	Bolt11Jit(PaymentHash hash, PaymentPreimage? preimage, PaymentSecret? secret, LSPFeeLimits lsp_fee_limits);
-	Bolt12Offer(PaymentHash? hash, PaymentPreimage? preimage, PaymentSecret? secret, OfferId offer_id);
-	Bolt12Refund(PaymentHash? hash, PaymentPreimage? preimage, PaymentSecret? secret);
+	Bolt12Offer(PaymentHash? hash, PaymentPreimage? preimage, PaymentSecret? secret, OfferId offer_id, UntrustedString? payer_note, u64? quantity);
+	Bolt12Refund(PaymentHash? hash, PaymentPreimage? preimage, PaymentSecret? secret, UntrustedString? payer_note, u64? quantity);
 	Spontaneous(PaymentHash hash, PaymentPreimage? preimage);
 };
 

src/error.rs

@@ -89,6 +89,8 @@ pub enum Error {
 	InvalidNetwork,
 	/// The given URI is invalid.
 	InvalidUri,
+	/// The given quantity is invalid.
+	InvalidQuantity,
 	/// A payment with the given hash has already been initiated.
 	DuplicatePayment,
 	/// The provided offer was denonminated in an unsupported currency.
@@ -153,6 +155,7 @@ impl fmt::Display for Error {
 			Self::InvalidChannelId => write!(f, "The given channel ID is invalid."),
 			Self::InvalidNetwork => write!(f, "The given network is invalid."),
 			Self::InvalidUri => write!(f, "The given URI is invalid."),
+			Self::InvalidQuantity => write!(f, "The given quantity is invalid."),
 			Self::DuplicatePayment => {
 				write!(f, "A payment with the given hash has already been initiated.")
 			},

src/event.rs

@@ -597,12 +597,16 @@ where
 						payment_context,
 						..
 					} => {
+						let payer_note = payment_context.invoice_request.payer_note_truncated;
 						let offer_id = payment_context.offer_id;
+						let quantity = payment_context.invoice_request.quantity;
 						let kind = PaymentKind::Bolt12Offer {
 							hash: Some(payment_hash),
 							preimage: payment_preimage,
 							secret: Some(payment_secret),
 							offer_id,
+							payer_note,
+							quantity,
 						};
 
 						let payment = PaymentDetails::new(

src/payment/bolt12.rs

@@ -12,12 +12,14 @@ use crate::types::ChannelManager;
 
 use lightning::ln::channelmanager::{PaymentId, Retry};
 use lightning::offers::invoice::Bolt12Invoice;
-use lightning::offers::offer::{Amount, Offer};
+use lightning::offers::offer::{Amount, Offer, Quantity};
 use lightning::offers::parse::Bolt12SemanticError;
 use lightning::offers::refund::Refund;
+use lightning::util::string::UntrustedString;
 
 use rand::RngCore;
 
+use std::num::NonZeroU64;
 use std::sync::{Arc, RwLock};
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
@@ -47,13 +49,15 @@ impl Bolt12Payment {
 	///
 	/// If `payer_note` is `Some` it will be seen by the recipient and reflected back in the invoice
 	/// response.
-	pub fn send(&self, offer: &Offer, payer_note: Option<String>) -> Result<PaymentId, Error> {
+	///
+	/// If `quantity` is `Some` it represents the number of items requested.
+	pub fn send(
+		&self, offer: &Offer, quantity: Option<u64>, payer_note: Option<String>,
+	) -> Result<PaymentId, Error> {
 		let rt_lock = self.runtime.read().unwrap();
 		if rt_lock.is_none() {
 			return Err(Error::NotRunning);
 		}
-
-		let quantity = None;
 		let mut random_bytes = [0u8; 32];
 		rand::thread_rng().fill_bytes(&mut random_bytes);
 		let payment_id = PaymentId(random_bytes);
@@ -76,7 +80,7 @@ impl Bolt12Payment {
 			&offer,
 			quantity,
 			None,
-			payer_note,
+			payer_note.clone(),
 			payment_id,
 			retry_strategy,
 			max_total_routing_fee_msat,
@@ -95,6 +99,8 @@ impl Bolt12Payment {
 					preimage: None,
 					secret: None,
 					offer_id: offer.id(),
+					payer_note: payer_note.map(UntrustedString),
+					quantity,
 				};
 				let payment = PaymentDetails::new(
 					payment_id,
@@ -117,6 +123,8 @@ impl Bolt12Payment {
 							preimage: None,
 							secret: None,
 							offer_id: offer.id(),
+							payer_note: payer_note.map(UntrustedString),
+							quantity,
 						};
 						let payment = PaymentDetails::new(
 							payment_id,
@@ -143,14 +151,13 @@ impl Bolt12Payment {
 	/// If `payer_note` is `Some` it will be seen by the recipient and reflected back in the invoice
 	/// response.
 	pub fn send_using_amount(
-		&self, offer: &Offer, payer_note: Option<String>, amount_msat: u64,
+		&self, offer: &Offer, amount_msat: u64, quantity: Option<u64>, payer_note: Option<String>,
 	) -> Result<PaymentId, Error> {
 		let rt_lock = self.runtime.read().unwrap();
 		if rt_lock.is_none() {
 			return Err(Error::NotRunning);
 		}
 
-		let quantity = None;
 		let mut random_bytes = [0u8; 32];
 		rand::thread_rng().fill_bytes(&mut random_bytes);
 		let payment_id = PaymentId(random_bytes);
@@ -177,7 +184,7 @@ impl Bolt12Payment {
 			&offer,
 			quantity,
 			Some(amount_msat),
-			payer_note,
+			payer_note.clone(),
 			payment_id,
 			retry_strategy,
 			max_total_routing_fee_msat,
@@ -196,6 +203,8 @@ impl Bolt12Payment {
 					preimage: None,
 					secret: None,
 					offer_id: offer.id(),
+					payer_note: payer_note.map(UntrustedString),
+					quantity,
 				};
 				let payment = PaymentDetails::new(
 					payment_id,
@@ -218,6 +227,8 @@ impl Bolt12Payment {
 							preimage: None,
 							secret: None,
 							offer_id: offer.id(),
+							payer_note: payer_note.map(UntrustedString),
+							quantity,
 						};
 						let payment = PaymentDetails::new(
 							payment_id,
@@ -236,21 +247,32 @@ impl Bolt12Payment {
 
 	/// Returns a payable offer that can be used to request and receive a payment of the amount
 	/// given.
-	pub fn receive(&self, amount_msat: u64, description: &str) -> Result<Offer, Error> {
+	pub fn receive(
+		&self, amount_msat: u64, description: &str, quantity: Option<u64>,
+	) -> Result<Offer, Error> {
 		let offer_builder = self.channel_manager.create_offer_builder().map_err(|e| {
 			log_error!(self.logger, "Failed to create offer builder: {:?}", e);
 			Error::OfferCreationFailed
 		})?;
-		let offer = offer_builder
-			.amount_msats(amount_msat)
-			.description(description.to_string())
-			.build()
-			.map_err(|e| {
-				log_error!(self.logger, "Failed to create offer: {:?}", e);
-				Error::OfferCreationFailed
-			})?;
 
-		Ok(offer)
+		let mut offer =
+			offer_builder.amount_msats(amount_msat).description(description.to_string());
+
+		if let Some(qty) = quantity {
+			if qty == 0 {
+				log_error!(self.logger, "Failed to create offer: quantity can't be zero.");
+				return Err(Error::InvalidQuantity);
+			} else {
+				offer = offer.supported_quantity(Quantity::Bounded(NonZeroU64::new(qty).unwrap()))
+			};
+		};
+
+		let finalized_offer = offer.build().map_err(|e| {
+			log_error!(self.logger, "Failed to create offer: {:?}", e);
+			Error::OfferCreationFailed
+		})?;
+
+		Ok(finalized_offer)
 	}
 
 	/// Returns a payable offer that can be used to request and receive a payment for which the
@@ -281,8 +303,13 @@ impl Bolt12Payment {
 		let payment_hash = invoice.payment_hash();
 		let payment_id = PaymentId(payment_hash.0);
 
-		let kind =
-			PaymentKind::Bolt12Refund { hash: Some(payment_hash), preimage: None, secret: None };
+		let kind = PaymentKind::Bolt12Refund {
+			hash: Some(payment_hash),
+			preimage: None,
+			secret: None,
+			payer_note: refund.payer_note().map(|note| UntrustedString(note.0.to_string())),
+			quantity: refund.quantity(),
+		};
 
 		let payment = PaymentDetails::new(
 			payment_id,
@@ -298,7 +325,10 @@ impl Bolt12Payment {
 	}
 
 	/// Returns a [`Refund`] object that can be used to offer a refund payment of the amount given.
-	pub fn initiate_refund(&self, amount_msat: u64, expiry_secs: u32) -> Result<Refund, Error> {
+	pub fn initiate_refund(
+		&self, amount_msat: u64, expiry_secs: u32, quantity: Option<u64>,
+		payer_note: Option<String>,
+	) -> Result<Refund, Error> {
 		let mut random_bytes = [0u8; 32];
 		rand::thread_rng().fill_bytes(&mut random_bytes);
 		let payment_id = PaymentId(random_bytes);
@@ -309,7 +339,7 @@ impl Bolt12Payment {
 		let retry_strategy = Retry::Timeout(LDK_PAYMENT_RETRY_TIMEOUT);
 		let max_total_routing_fee_msat = None;
 
-		let refund = self
+		let mut refund_builder = self
 			.channel_manager
 			.create_refund_builder(
 				amount_msat,
@@ -321,17 +351,30 @@ impl Bolt12Payment {
 			.map_err(|e| {
 				log_error!(self.logger, "Failed to create refund builder: {:?}", e);
 				Error::RefundCreationFailed
-			})?
-			.build()
-			.map_err(|e| {
-				log_error!(self.logger, "Failed to create refund: {:?}", e);
-				Error::RefundCreationFailed
 			})?;
 
-		log_info!(self.logger, "Offering refund of {}msat", amount_msat);
+		if let Some(qty) = quantity {
+			refund_builder = refund_builder.quantity(qty);
+		}
+
+		if let Some(note) = payer_note.clone() {
+			refund_builder = refund_builder.payer_note(note);
+		}
+
+		let refund = refund_builder.build().map_err(|e| {
+			log_error!(self.logger, "Failed to create refund: {:?}", e);
+			Error::RefundCreationFailed
+		})?;
 
-		let kind = PaymentKind::Bolt12Refund { hash: None, preimage: None, secret: None };
+		log_info!(self.logger, "Offering refund of {}msat", amount_msat);
 
+		let kind = PaymentKind::Bolt12Refund {
+			hash: None,
+			preimage: None,
+			secret: None,
+			payer_note: payer_note.map(|note| UntrustedString(note)),
+			quantity,
+		};
 		let payment = PaymentDetails::new(
 			payment_id,
 			kind,

src/payment/store.rs

@@ -11,6 +11,7 @@ use lightning::ln::msgs::DecodeError;
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 use lightning::offers::offer::OfferId;
 use lightning::util::ser::{Readable, Writeable};
+use lightning::util::string::UntrustedString;
 use lightning::{
 	_init_and_read_len_prefixed_tlv_fields, impl_writeable_tlv_based,
 	impl_writeable_tlv_based_enum, write_tlv_fields,
@@ -212,6 +213,18 @@ pub enum PaymentKind {
 		secret: Option<PaymentSecret>,
 		/// The ID of the offer this payment is for.
 		offer_id: OfferId,
+		/// The payer note for the payment.
+		///
+		/// Truncated to [`PAYER_NOTE_LIMIT`] characters.
+		///
+		/// This will always be `None` for payments serialized with version `v0.3.0`.
+		///
+		/// [`PAYER_NOTE_LIMIT`]: lightning::offers::invoice_request::PAYER_NOTE_LIMIT
+		payer_note: Option<UntrustedString>,
+		/// The quantity of an item requested in the offer.
+		///
+		/// This will always be `None` for payments serialized with version `v0.3.0`.
+		quantity: Option<u64>,
 	},
 	/// A [BOLT 12] 'refund' payment, i.e., a payment for a [`Refund`].
 	///
@@ -224,6 +237,14 @@ pub enum PaymentKind {
 		preimage: Option<PaymentPreimage>,
 		/// The secret used by the payment.
 		secret: Option<PaymentSecret>,
+		/// The payer note for the refund payment.
+		///
+		/// This will always be `None` for payments serialized with version `v0.3.0`.
+		payer_note: Option<UntrustedString>,
+		/// The quantity of an item that the refund is for.
+		///
+		/// This will always be `None` for payments serialized with version `v0.3.0`.
+		quantity: Option<u64>,
 	},
 	/// A spontaneous ("keysend") payment.
 	Spontaneous {
@@ -249,7 +270,9 @@ impl_writeable_tlv_based_enum!(PaymentKind,
 	},
 	(6, Bolt12Offer) => {
 		(0, hash, option),
+		(1, payer_note, option),
 		(2, preimage, option),
+		(3, quantity, option),
 		(4, secret, option),
 		(6, offer_id, required),
 	},
@@ -259,7 +282,9 @@ impl_writeable_tlv_based_enum!(PaymentKind,
 	},
 	(10, Bolt12Refund) => {
 		(0, hash, option),
+		(1, payer_note, option),
 		(2, preimage, option),
+		(3, quantity, option),
 		(4, secret, option),
 	};
 );

src/payment/unified_qr.rs

@@ -92,7 +92,7 @@ impl UnifiedQrPayment {
 
 		let amount_msats = amount_sats * 1_000;
 
-		let bolt12_offer = match self.bolt12_payment.receive(amount_msats, description) {
+		let bolt12_offer = match self.bolt12_payment.receive(amount_msats, description, None) {
 			Ok(offer) => Some(offer),
 			Err(e) => {
 				log_error!(self.logger, "Failed to create offer: {}", e);
@@ -136,7 +136,7 @@ impl UnifiedQrPayment {
 			uri.clone().require_network(self.config.network).map_err(|_| Error::InvalidNetwork)?;
 
 		if let Some(offer) = uri_network_checked.extras.bolt12_offer {
-			match self.bolt12_payment.send(&offer, None) {
+			match self.bolt12_payment.send(&offer, None, None) {
 				Ok(payment_id) => return Ok(QrPaymentResult::Bolt12 { payment_id }),
 				Err(e) => log_error!(self.logger, "Failed to send BOLT12 offer: {:?}. This is part of a unified QR code payment. Falling back to the BOLT11 invoice.", e),
 			}