f - remove fallback from ChannelManager

Author: jkczyz

lightning/src/ln/channelmanager.rs

@@ -7658,7 +7658,9 @@ where
 
 		match self.create_inbound_payment(Some(amount_msats), relative_expiry, None) {
 			Ok((payment_hash, payment_secret)) => {
-				let payment_paths = self.create_blinded_payment_paths(amount_msats, payment_secret);
+				let payment_paths = self.create_blinded_payment_paths(amount_msats, payment_secret)
+					.map_err(|_| Bolt12SemanticError::MissingPaths)?;
+
 				#[cfg(not(feature = "no-std"))]
 				let builder = refund.respond_using_derived_keys(
 					payment_paths, payment_hash, expanded_key, entropy
@@ -7819,49 +7821,9 @@ where
 			.and_then(|paths| paths.into_iter().next().ok_or(()))
 	}
 
-	/// Creates multi-hop blinded payment paths for the given `amount_msats` by delegating to
-	/// [`Router::create_blinded_payment_paths`]. If the router returns an error or no paths,
-	/// creates a one-hop blinded payment path instead.
-	fn create_blinded_payment_paths(
-		&self, amount_msats: u64, payment_secret: PaymentSecret
-	) -> Vec<(BlindedPayInfo, BlindedPath)> {
-		self.create_multi_hop_blinded_payment_paths(amount_msats, payment_secret)
-			.ok()
-			.and_then(|paths| (!paths.is_empty()).then(|| paths))
-			.unwrap_or_else(|| vec![self.create_one_hop_blinded_payment_path(payment_secret)])
-	}
-
-	/// Creates a one-hop blinded payment path with [`ChannelManager::get_our_node_id`] as the
-	/// introduction node.
-	fn create_one_hop_blinded_payment_path(
-		&self, payment_secret: PaymentSecret
-	) -> (BlindedPayInfo, BlindedPath) {
-		let entropy_source = self.entropy_source.deref();
-		let secp_ctx = &self.secp_ctx;
-
-		let payee_node_id = self.get_our_node_id();
-		let max_cltv_expiry = self.best_block.read().unwrap().height() + LATENCY_GRACE_PERIOD_BLOCKS;
-		let payee_tlvs = ReceiveTlvs {
-			payment_secret,
-			payment_constraints: PaymentConstraints {
-				max_cltv_expiry,
-				htlc_minimum_msat: 1,
-			},
-		};
-		// TODO: Err for overflow?
-		BlindedPath::one_hop_for_payment(
-			payee_node_id, payee_tlvs, entropy_source, secp_ctx
-		).unwrap()
-	}
-
 	/// Creates multi-hop blinded payment paths for the given `amount_msats` by delegating to
 	/// [`Router::create_blinded_payment_paths`].
-	///
-	/// May return no paths if no peers [support route blinding] or whose channels don't have enough
-	/// inbound liquidity.
-	///
-	/// [support route blinding]: crate::ln::features::InitFeatures::supports_route_blinding
-	fn create_multi_hop_blinded_payment_paths(
+	fn create_blinded_payment_paths(
 		&self, amount_msats: u64, payment_secret: PaymentSecret
 	) -> Result<Vec<(BlindedPayInfo, BlindedPath)>, ()> {
 		let entropy_source = self.entropy_source.deref();
@@ -9133,9 +9095,15 @@ where
 
 				match self.create_inbound_payment(Some(amount_msats), relative_expiry, None) {
 					Ok((payment_hash, payment_secret)) if invoice_request.keys.is_some() => {
-						let payment_paths = self.create_blinded_payment_paths(
+						let payment_paths = match self.create_blinded_payment_paths(
 							amount_msats, payment_secret
-						);
+						) {
+							Ok(payment_paths) => payment_paths,
+							Err(()) => {
+								let error = Bolt12SemanticError::MissingPaths;
+								return Some(OffersMessage::InvoiceError(error.into()));
+							},
+						};
 						#[cfg(not(feature = "no-std"))]
 						let builder = invoice_request.respond_using_derived_keys(
 							payment_paths, payment_hash
@@ -9154,9 +9122,16 @@ where
 						}
 					},
 					Ok((payment_hash, payment_secret)) => {
-						let payment_paths = self.create_blinded_payment_paths(
+						let payment_paths = match self.create_blinded_payment_paths(
 							amount_msats, payment_secret
-						);
+						) {
+							Ok(payment_paths) => payment_paths,
+							Err(()) => {
+								let error = Bolt12SemanticError::MissingPaths;
+								return Some(OffersMessage::InvoiceError(error.into()));
+							},
+						};
+
 						#[cfg(not(feature = "no-std"))]
 						let builder = invoice_request.respond_with(payment_paths, payment_hash);
 						#[cfg(feature = "no-std")]