Merge pull request lightningdevkit#3245 from valentinewallace/2024-07-blinded-pay-path-refactor

Move `BlindedPayInfo` into `BlindedPaymentPath`

Author: TheBlueMatt

fuzz/src/chanmon_consistency.rs

@@ -56,7 +56,7 @@ use lightning::ln::msgs::{
 };
 use lightning::ln::script::ShutdownScript;
 use lightning::ln::types::{ChannelId, PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::offers::invoice::{BlindedPayInfo, UnsignedBolt12Invoice};
+use lightning::offers::invoice::UnsignedBolt12Invoice;
 use lightning::offers::invoice_request::UnsignedInvoiceRequest;
 use lightning::onion_message::messenger::{Destination, MessageRouter, OnionMessagePath};
 use lightning::routing::router::{InFlightHtlcs, Path, Route, RouteHop, RouteParameters, Router};
@@ -126,7 +126,7 @@ impl Router for FuzzRouter {
 	fn create_blinded_payment_paths<T: secp256k1::Signing + secp256k1::Verification>(
 		&self, _recipient: PublicKey, _first_hops: Vec<ChannelDetails>, _tlvs: ReceiveTlvs,
 		_amount_msats: u64, _secp_ctx: &Secp256k1<T>,
-	) -> Result<Vec<(BlindedPayInfo, BlindedPaymentPath)>, ()> {
+	) -> Result<Vec<BlindedPaymentPath>, ()> {
 		unreachable!()
 	}
 }

fuzz/src/full_stack.rs

@@ -49,7 +49,7 @@ use lightning::ln::peer_handler::{
 };
 use lightning::ln::script::ShutdownScript;
 use lightning::ln::types::{ChannelId, PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::offers::invoice::{BlindedPayInfo, UnsignedBolt12Invoice};
+use lightning::offers::invoice::UnsignedBolt12Invoice;
 use lightning::offers::invoice_request::UnsignedInvoiceRequest;
 use lightning::onion_message::messenger::{Destination, MessageRouter, OnionMessagePath};
 use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
@@ -163,7 +163,7 @@ impl Router for FuzzRouter {
 	fn create_blinded_payment_paths<T: secp256k1::Signing + secp256k1::Verification>(
 		&self, _recipient: PublicKey, _first_hops: Vec<ChannelDetails>, _tlvs: ReceiveTlvs,
 		_amount_msats: u64, _secp_ctx: &Secp256k1<T>,
-	) -> Result<Vec<(BlindedPayInfo, BlindedPaymentPath)>, ()> {
+	) -> Result<Vec<BlindedPaymentPath>, ()> {
 		unreachable!()
 	}
 }

fuzz/src/router.rs

@@ -12,15 +12,14 @@ use bitcoin::constants::ChainHash;
 use bitcoin::script::Builder;
 use bitcoin::transaction::TxOut;
 
-use lightning::blinded_path::payment::BlindedPaymentPath;
+use lightning::blinded_path::payment::{BlindedPayInfo, BlindedPaymentPath};
 use lightning::blinded_path::BlindedHop;
 use lightning::chain::transaction::OutPoint;
 use lightning::ln::channel_state::{ChannelCounterparty, ChannelDetails, ChannelShutdownState};
 use lightning::ln::channelmanager;
 use lightning::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
 use lightning::ln::msgs;
 use lightning::ln::types::ChannelId;
-use lightning::offers::invoice::BlindedPayInfo;
 use lightning::routing::gossip::{NetworkGraph, RoutingFees};
 use lightning::routing::router::{
 	find_route, PaymentParameters, RouteHint, RouteHintHop, RouteParameters,
@@ -381,7 +380,7 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 				let mut last_hops_unblinded = Vec::new();
 				last_hops!(last_hops_unblinded);
 				let dummy_pk = PublicKey::from_slice(&[2; 33]).unwrap();
-				let last_hops: Vec<(BlindedPayInfo, BlindedPaymentPath)> = last_hops_unblinded
+				let last_hops: Vec<BlindedPaymentPath> = last_hops_unblinded
 					.into_iter()
 					.map(|hint| {
 						let hop = &hint.0[0];
@@ -401,9 +400,11 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 								encrypted_payload: Vec::new(),
 							});
 						}
-						(
+						BlindedPaymentPath::from_raw(
+							hop.src_node_id,
+							dummy_pk,
+							blinded_hops,
 							payinfo,
-							BlindedPaymentPath::from_raw(hop.src_node_id, dummy_pk, blinded_hops),
 						)
 					})
 					.collect();

lightning/src/blinded_path/mod.rs

@@ -26,7 +26,7 @@ use crate::prelude::*;
 /// Onion messages and payments can be sent and received to blinded paths, which serve to hide the
 /// identity of the recipient.
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
-struct BlindedPath {
+pub(crate) struct BlindedPath {
 	/// To send to a blinded path, the sender first finds a route to the unblinded
 	/// `introduction_node`, which can unblind its [`encrypted_payload`] to find out the onion
 	/// message or payment's next hop and forward it along.

lightning/src/blinded_path/payment.rs

@@ -21,7 +21,6 @@ use crate::ln::channel_state::CounterpartyForwardingInfo;
 use crate::ln::features::BlindedHopFeatures;
 use crate::ln::msgs::DecodeError;
 use crate::ln::onion_utils;
-use crate::offers::invoice::BlindedPayInfo;
 use crate::offers::invoice_request::InvoiceRequestFields;
 use crate::offers::offer::OfferId;
 use crate::routing::gossip::{NodeId, ReadOnlyNetworkGraph};
@@ -34,29 +33,59 @@ use core::ops::Deref;
 #[allow(unused_imports)]
 use crate::prelude::*;
 
-/// A blinded path to be used for sending or receiving a payment, hiding the identity of the
-/// recipient.
-#[derive(Clone, Debug, Hash, PartialEq, Eq)]
-pub struct BlindedPaymentPath(pub(super) BlindedPath);
+/// Information needed to route a payment across a [`BlindedPaymentPath`].
+#[derive(Clone, Debug, Hash, Eq, PartialEq)]
+pub struct BlindedPayInfo {
+	/// Base fee charged (in millisatoshi) for the entire blinded path.
+	pub fee_base_msat: u32,
 
-impl Writeable for BlindedPaymentPath {
-	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		self.0.write(w)
-	}
+	/// Liquidity fee charged (in millionths of the amount transferred) for the entire blinded path
+	/// (i.e., 10,000 is 1%).
+	pub fee_proportional_millionths: u32,
+
+	/// Number of blocks subtracted from an incoming HTLC's `cltv_expiry` for the entire blinded
+	/// path.
+	pub cltv_expiry_delta: u16,
+
+	/// The minimum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
+	/// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
+	/// seen by the recipient.
+	pub htlc_minimum_msat: u64,
+
+	/// The maximum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
+	/// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
+	/// seen by the recipient.
+	pub htlc_maximum_msat: u64,
+
+	/// Features set in `encrypted_data_tlv` for the `encrypted_recipient_data` TLV record in an
+	/// onion payload.
+	pub features: BlindedHopFeatures,
 }
 
-impl Readable for BlindedPaymentPath {
-	fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
-		Ok(Self(BlindedPath::read(r)?))
-	}
+impl_writeable!(BlindedPayInfo, {
+	fee_base_msat,
+	fee_proportional_millionths,
+	cltv_expiry_delta,
+	htlc_minimum_msat,
+	htlc_maximum_msat,
+	features
+});
+
+/// A blinded path to be used for sending or receiving a payment, hiding the identity of the
+/// recipient.
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
+pub struct BlindedPaymentPath {
+	pub(super) inner_path: BlindedPath,
+	/// The [`BlindedPayInfo`] used to pay this blinded path.
+	pub payinfo: BlindedPayInfo,
 }
 
 impl BlindedPaymentPath {
 	/// Create a one-hop blinded path for a payment.
 	pub fn one_hop<ES: Deref, T: secp256k1::Signing + secp256k1::Verification>(
 		payee_node_id: PublicKey, payee_tlvs: ReceiveTlvs, min_final_cltv_expiry_delta: u16,
 		entropy_source: ES, secp_ctx: &Secp256k1<T>
-	) -> Result<(BlindedPayInfo, Self), ()> where ES::Target: EntropySource {
+	) -> Result<Self, ()> where ES::Target: EntropySource {
 		// This value is not considered in pathfinding for 1-hop blinded paths, because it's intended to
 		// be in relation to a specific channel.
 		let htlc_maximum_msat = u64::max_value();
@@ -77,7 +106,7 @@ impl BlindedPaymentPath {
 		intermediate_nodes: &[ForwardNode], payee_node_id: PublicKey, payee_tlvs: ReceiveTlvs,
 		htlc_maximum_msat: u64, min_final_cltv_expiry_delta: u16, entropy_source: ES,
 		secp_ctx: &Secp256k1<T>
-	) -> Result<(BlindedPayInfo, Self), ()> where ES::Target: EntropySource {
+	) -> Result<Self, ()> where ES::Target: EntropySource {
 		let introduction_node = IntroductionNode::NodeId(
 			intermediate_nodes.first().map_or(payee_node_id, |n| n.node_id)
 		);
@@ -87,38 +116,41 @@ impl BlindedPaymentPath {
 		let blinded_payinfo = compute_payinfo(
 			intermediate_nodes, &payee_tlvs, htlc_maximum_msat, min_final_cltv_expiry_delta
 		)?;
-		Ok((blinded_payinfo, Self(BlindedPath {
-			introduction_node,
-			blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret),
-			blinded_hops: blinded_hops(
-				secp_ctx, intermediate_nodes, payee_node_id, payee_tlvs, &blinding_secret
-			).map_err(|_| ())?,
-		})))
+		Ok(Self {
+			inner_path: BlindedPath {
+				introduction_node,
+				blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret),
+				blinded_hops: blinded_hops(
+					secp_ctx, intermediate_nodes, payee_node_id, payee_tlvs, &blinding_secret
+				).map_err(|_| ())?,
+			},
+			payinfo: blinded_payinfo
+		})
 	}
 
 	/// Returns the introduction [`NodeId`] of the blinded path, if it is publicly reachable (i.e.,
 	/// it is found in the network graph).
 	pub fn public_introduction_node_id<'a>(
 		&self, network_graph: &'a ReadOnlyNetworkGraph
 	) -> Option<&'a NodeId> {
-		self.0.public_introduction_node_id(network_graph)
+		self.inner_path.public_introduction_node_id(network_graph)
 	}
 
 	/// The [`IntroductionNode`] of the blinded path.
 	pub fn introduction_node(&self) -> &IntroductionNode {
-		&self.0.introduction_node
+		&self.inner_path.introduction_node
 	}
 
 	/// Used by the [`IntroductionNode`] to decrypt its [`encrypted_payload`] to forward the payment.
 	///
 	/// [`encrypted_payload`]: BlindedHop::encrypted_payload
 	pub fn blinding_point(&self) -> PublicKey {
-		self.0.blinding_point
+		self.inner_path.blinding_point
 	}
 
 	/// The [`BlindedHop`]s within the blinded path.
 	pub fn blinded_hops(&self) -> &[BlindedHop] {
-		&self.0.blinded_hops
+		&self.inner_path.blinded_hops
 	}
 
 	/// Advance the blinded onion payment path by one hop, making the second hop into the new
@@ -133,9 +165,9 @@ impl BlindedPaymentPath {
 		NL::Target: NodeIdLookUp,
 		T: secp256k1::Signing + secp256k1::Verification,
 	{
-		let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &self.0.blinding_point, None)?;
+		let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &self.inner_path.blinding_point, None)?;
 		let rho = onion_utils::gen_rho_from_shared_secret(&control_tlvs_ss.secret_bytes());
-		let encrypted_control_tlvs = &self.0.blinded_hops.get(0).ok_or(())?.encrypted_payload;
+		let encrypted_control_tlvs = &self.inner_path.blinded_hops.get(0).ok_or(())?.encrypted_payload;
 		let mut s = Cursor::new(encrypted_control_tlvs);
 		let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
 		match ChaChaPolyReadAdapter::read(&mut reader, rho) {
@@ -147,31 +179,43 @@ impl BlindedPaymentPath {
 					None => return Err(()),
 				};
 				let mut new_blinding_point = onion_utils::next_hop_pubkey(
-					secp_ctx, self.0.blinding_point, control_tlvs_ss.as_ref()
+					secp_ctx, self.inner_path.blinding_point, control_tlvs_ss.as_ref()
 				).map_err(|_| ())?;
-				mem::swap(&mut self.0.blinding_point, &mut new_blinding_point);
-				self.0.introduction_node = IntroductionNode::NodeId(next_node_id);
-				self.0.blinded_hops.remove(0);
+				mem::swap(&mut self.inner_path.blinding_point, &mut new_blinding_point);
+				self.inner_path.introduction_node = IntroductionNode::NodeId(next_node_id);
+				self.inner_path.blinded_hops.remove(0);
 				Ok(())
 			},
 			_ => Err(())
 		}
 	}
 
+	pub(crate) fn inner_blinded_path(&self) -> &BlindedPath {
+		&self.inner_path
+	}
+
+	pub(crate) fn from_parts(inner_path: BlindedPath, payinfo: BlindedPayInfo) -> Self {
+		Self { inner_path, payinfo }
+	}
+
 	#[cfg(any(test, fuzzing))]
 	pub fn from_raw(
-		introduction_node_id: PublicKey, blinding_point: PublicKey, blinded_hops: Vec<BlindedHop>
+		introduction_node_id: PublicKey, blinding_point: PublicKey, blinded_hops: Vec<BlindedHop>,
+		payinfo: BlindedPayInfo
 	) -> Self {
-		Self(BlindedPath {
-			introduction_node: IntroductionNode::NodeId(introduction_node_id),
-			blinding_point,
-			blinded_hops,
-		})
+		Self {
+			inner_path: BlindedPath {
+				introduction_node: IntroductionNode::NodeId(introduction_node_id),
+				blinding_point,
+				blinded_hops,
+			},
+			payinfo
+		}
 	}
 
 	#[cfg(test)]
 	pub fn clear_blinded_hops(&mut self) {
-		self.0.blinded_hops.clear()
+		self.inner_path.blinded_hops.clear()
 	}
 }
 

lightning/src/ln/blinded_payment_tests.rs

@@ -25,7 +25,7 @@ use crate::ln::onion_payment;
 use crate::ln::onion_utils;
 use crate::ln::onion_utils::INVALID_ONION_BLINDING;
 use crate::ln::outbound_payment::{Retry, IDEMPOTENCY_TIMEOUT_TICKS};
-use crate::offers::invoice::{BlindedPayInfo, UnsignedBolt12Invoice};
+use crate::offers::invoice::UnsignedBolt12Invoice;
 use crate::offers::invoice_request::UnsignedInvoiceRequest;
 use crate::prelude::*;
 use crate::routing::router::{BlindedTail, Path, Payee, PaymentParameters, RouteHop, RouteParameters};
@@ -39,7 +39,7 @@ fn blinded_payment_path(
 	payment_secret: PaymentSecret, intro_node_min_htlc: u64, intro_node_max_htlc: u64,
 	node_ids: Vec<PublicKey>, channel_upds: &[&msgs::UnsignedChannelUpdate],
 	keys_manager: &test_utils::TestKeysInterface
-) -> (BlindedPayInfo, BlindedPaymentPath) {
+) -> BlindedPaymentPath {
 	let mut intermediate_nodes = Vec::new();
 	let mut intro_node_min_htlc_opt = Some(intro_node_min_htlc);
 	let mut intro_node_max_htlc_opt = Some(intro_node_max_htlc);
@@ -839,11 +839,12 @@ fn do_multi_hop_receiver_fail(check: ReceiveCheckFail) {
 				nodes.iter().skip(1).map(|n| n.node.get_our_node_id()).collect(), &[&high_htlc_minimum_upd],
 				&chanmon_cfgs[2].keys_manager);
 			if let Payee::Blinded { route_hints, .. } = high_htlc_min_params.payment_params.payee {
-				route_hints[0].1.clone()
+				route_hints[0].clone()
 			} else { panic!() }
 		};
 		if let Payee::Blinded { ref mut route_hints, .. } = route_params.payment_params.payee {
-			route_hints[0].1 = high_htlc_min_bp;
+			route_hints[0] = high_htlc_min_bp;
+			route_hints[0].payinfo.htlc_minimum_msat = amt_msat;
 		} else { panic!() }
 		find_route(&nodes[0], &route_params).unwrap()
 	} else {
@@ -1121,7 +1122,7 @@ fn min_htlc() {
 		nodes[2].node.get_our_node_id(), nodes[3].node.get_our_node_id()],
 		&[&chan_1_2.0.contents, &chan_2_3.0.contents], &chanmon_cfgs[3].keys_manager);
 	assert_eq!(min_htlc_msat,
-		route_params.payment_params.payee.blinded_route_hints()[0].0.htlc_minimum_msat);
+		route_params.payment_params.payee.blinded_route_hints()[0].payinfo.htlc_minimum_msat);
 
 	nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params.clone(), Retry::Attempts(0)).unwrap();
 	check_added_monitors(&nodes[0], 1);
@@ -1133,7 +1134,7 @@ fn min_htlc() {
 		nodes[0].node.timer_tick_occurred();
 	}
 	if let Payee::Blinded { ref mut route_hints, .. } = route_params.payment_params.payee {
-		route_hints[0].0.htlc_minimum_msat -= 1;
+		route_hints[0].payinfo.htlc_minimum_msat -= 1;
 	} else { panic!() }
 	route_params.final_value_msat -= 1;
 	nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();

lightning/src/ln/channelmanager.rs

@@ -62,7 +62,7 @@ use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
 use crate::ln::outbound_payment;
 use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration};
 use crate::ln::wire::Encode;
-use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder, UnsignedBolt12Invoice};
+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::nonce::Nonce;
@@ -9373,7 +9373,7 @@ where
 	/// [`Router::create_blinded_payment_paths`].
 	fn create_blinded_payment_paths(
 		&self, amount_msats: u64, payment_secret: PaymentSecret, payment_context: PaymentContext
-	) -> Result<Vec<(BlindedPayInfo, BlindedPaymentPath)>, ()> {
+	) -> Result<Vec<BlindedPaymentPath>, ()> {
 		let secp_ctx = &self.secp_ctx;
 
 		let first_hops = self.list_usable_channels();