f - check invalid amount

Author: jkczyz

lightning/src/offers/offer.rs

@@ -61,6 +61,7 @@ use core::ops::{Bound, RangeBounds};
 use core::time::Duration;
 use io;
 use ln::features::OfferFeatures;
+use ln::msgs::MAX_VALUE_MSAT;
 use onion_message::BlindedPath;
 use util::ser::{Writeable, Writer};
 
@@ -204,6 +205,14 @@ impl OfferBuilder {
 
 	/// Builds an [`Offer`] from the builder's settings.
 	pub fn build(self) -> Result<Offer, ()> {
+		if let Some(Amount::Currency { .. }) = self.offer.amount {
+			return Err(());
+		}
+
+		if self.offer.amount_msats() > MAX_VALUE_MSAT {
+			return Err(());
+		}
+
 		if self.offer.quantity_min() > self.offer.quantity_max() {
 			return Err(());
 		}
@@ -332,6 +341,10 @@ impl Offer {
 }
 
 impl OfferContents {
+	pub fn amount_msats(&self) -> u64 {
+		self.amount.as_ref().map(Amount::as_msats).unwrap_or(0)
+	}
+
 	pub fn quantity_min(&self) -> u64 {
 		self.quantity_min.unwrap_or(1)
 	}
@@ -395,6 +408,16 @@ pub enum Amount {
 	},
 }
 
+impl Amount {
+	/// Returns the amount in millisatoshi.
+	pub fn as_msats(&self) -> u64 {
+		match self {
+			Amount::Currency { .. } => unimplemented!(),
+			Amount::Bitcoin { amount_msats } => *amount_msats,
+		}
+	}
+}
+
 /// An ISO 4712 three-letter currency code (e.g., USD).
 pub type CurrencyCode = [u8; 3];
 
@@ -423,6 +446,7 @@ mod tests {
 	use core::num::NonZeroU64;
 	use core::time::Duration;
 	use ln::features::OfferFeatures;
+	use ln::msgs::MAX_VALUE_MSAT;
 	use onion_message::{BlindedHop, BlindedPath};
 	use util::ser::Writeable;
 
@@ -535,14 +559,16 @@ mod tests {
 		assert_eq!(tlv_stream.amount, Some(1000));
 		assert_eq!(tlv_stream.currency, None);
 
-		let offer = OfferBuilder::new("foo".into(), pubkey(42))
-			.amount(currency_amount.clone())
-			.build()
-			.unwrap();
-		let tlv_stream = offer.as_tlv_stream();
-		assert_eq!(offer.amount(), Some(&currency_amount));
+		let builder = OfferBuilder::new("foo".into(), pubkey(42))
+			.amount(currency_amount.clone());
+		let tlv_stream = builder.offer.as_tlv_stream();
+		assert_eq!(builder.offer.amount.as_ref(), Some(&currency_amount));
 		assert_eq!(tlv_stream.amount, Some(10));
 		assert_eq!(tlv_stream.currency, Some(b"USD"));
+		match builder.build() {
+			Ok(_) => panic!("expected error"),
+			Err(e) => assert_eq!(e, ()),
+		}
 
 		let offer = OfferBuilder::new("foo".into(), pubkey(42))
 			.amount(currency_amount.clone())
@@ -552,6 +578,12 @@ mod tests {
 		let tlv_stream = offer.as_tlv_stream();
 		assert_eq!(tlv_stream.amount, Some(1000));
 		assert_eq!(tlv_stream.currency, None);
+
+		let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
+		match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
+			Ok(_) => panic!("expected error"),
+			Err(e) => assert_eq!(e, ()),
+		}
 	}
 
 	#[test]