Struct-ify blinded payment path intermediate node info

diff --git a/lightning/src/blinded_path/mod.rs b/lightning/src/blinded_path/mod.rs
index 82d50546ddd6c81f2de149333e1c30ee96754397..927bbea9f6e99ab6e15db2cbb619af0e187060ec 100644 (file)
--- a/lightning/src/blinded_path/mod.rs
+++ b/lightning/src/blinded_path/mod.rs
@@ -76,8 +76,7 @@ impl BlindedPath {
                })
        }
 
-       /// Create a blinded path for a payment, to be forwarded along `intermediate_nodes`, where each
-       /// node is composed of `(node_id, tlvs, htlc_maximum_msat)`.
+       /// Create a blinded path for a payment, to be forwarded along `intermediate_nodes`.
        ///
        /// Errors if:
        /// * a provided node id is invalid
@@ -87,7 +86,7 @@ impl BlindedPath {
        /// [`ForwardTlvs`]: crate::blinded_path::payment::ForwardTlvs
        //  TODO: make all payloads the same size with padding + add dummy hops
        pub fn new_for_payment<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>(
-               intermediate_nodes: &[(PublicKey, payment::ForwardTlvs, u64)], payee_node_id: PublicKey,
+               intermediate_nodes: &[payment::ForwardNode], payee_node_id: PublicKey,
                payee_tlvs: payment::ReceiveTlvs, htlc_maximum_msat: u64, entropy_source: &ES,
                secp_ctx: &Secp256k1<T>
        ) -> Result<(BlindedPayInfo, Self), ()> {
@@ -96,7 +95,7 @@ impl BlindedPath {
 
                let blinded_payinfo = payment::compute_payinfo(intermediate_nodes, &payee_tlvs, htlc_maximum_msat)?;
                Ok((blinded_payinfo, BlindedPath {
-                       introduction_node_id: intermediate_nodes.first().map_or(payee_node_id, |n| n.0),
+                       introduction_node_id: intermediate_nodes.first().map_or(payee_node_id, |n| n.node_id),
                        blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret),
                        blinded_hops: payment::blinded_hops(
                                secp_ctx, intermediate_nodes, payee_node_id, payee_tlvs, &blinding_secret

diff --git a/lightning/src/blinded_path/payment.rs b/lightning/src/blinded_path/payment.rs
index 25031f9b47249176829b879690ea210d890e6e59..32181f7889c350fa3f23f2bdfe37a437d99808d4 100644 (file)
--- a/lightning/src/blinded_path/payment.rs
+++ b/lightning/src/blinded_path/payment.rs
@@ -16,6 +16,18 @@ use crate::util::ser::{Readable, Writeable, Writer};
 
 use core::convert::TryFrom;
 
+/// An intermediate node, its outbound channel, and relay parameters.
+#[derive(Clone, Debug)]
+pub struct ForwardNode {
+       /// The TLVs for this node's [`BlindedHop`], where the fee parameters contained within are also
+       /// used for [`BlindedPayInfo`] construction.
+       pub tlvs: ForwardTlvs,
+       /// This node's pubkey.
+       pub node_id: PublicKey,
+       /// The maximum value, in msat, that may be accepted by this node.
+       pub htlc_maximum_msat: u64,
+}
+
 /// Data to construct a [`BlindedHop`] for forwarding a payment.
 #[derive(Clone, Debug)]
 pub struct ForwardTlvs {
@@ -150,12 +162,12 @@ impl Readable for BlindedPaymentTlvs {
 
 /// Construct blinded payment hops for the given `intermediate_nodes` and payee info.
 pub(super) fn blinded_hops<T: secp256k1::Signing + secp256k1::Verification>(
-       secp_ctx: &Secp256k1<T>, intermediate_nodes: &[(PublicKey, ForwardTlvs, u64)],
+       secp_ctx: &Secp256k1<T>, intermediate_nodes: &[ForwardNode],
        payee_node_id: PublicKey, payee_tlvs: ReceiveTlvs, session_priv: &SecretKey
 ) -> Result<Vec<BlindedHop>, secp256k1::Error> {
-       let pks = intermediate_nodes.iter().map(|(pk, _, _)| pk)
+       let pks = intermediate_nodes.iter().map(|node| &node.node_id)
                .chain(core::iter::once(&payee_node_id));
-       let tlvs = intermediate_nodes.iter().map(|(_, tlvs, _)| BlindedPaymentTlvsRef::Forward(tlvs))
+       let tlvs = intermediate_nodes.iter().map(|node| BlindedPaymentTlvsRef::Forward(&node.tlvs))
                .chain(core::iter::once(BlindedPaymentTlvsRef::Receive(&payee_tlvs)));
        utils::construct_blinded_hops(secp_ctx, pks, tlvs, session_priv)
 }
@@ -182,13 +194,12 @@ fn amt_to_forward_msat(inbound_amt_msat: u64, payment_relay: &PaymentRelay) -> O
 }
 
 pub(super) fn compute_payinfo(
-       intermediate_nodes: &[(PublicKey, ForwardTlvs, u64)], payee_tlvs: &ReceiveTlvs,
-       payee_htlc_maximum_msat: u64
+       intermediate_nodes: &[ForwardNode], payee_tlvs: &ReceiveTlvs, payee_htlc_maximum_msat: u64
 ) -> Result<BlindedPayInfo, ()> {
        let mut curr_base_fee: u64 = 0;
        let mut curr_prop_mil: u64 = 0;
        let mut cltv_expiry_delta: u16 = 0;
-       for (_, tlvs, _) in intermediate_nodes.iter().rev() {
+       for tlvs in intermediate_nodes.iter().rev().map(|n| &n.tlvs) {
                // In the future, we'll want to take the intersection of all supported features for the
                // `BlindedPayInfo`, but there are no features in that context right now.
                if tlvs.features.requires_unknown_bits_from(&BlindedHopFeatures::empty()) { return Err(()) }
@@ -215,16 +226,16 @@ pub(super) fn compute_payinfo(
 
        let mut htlc_minimum_msat: u64 = 1;
        let mut htlc_maximum_msat: u64 = 21_000_000 * 100_000_000 * 1_000; // Total bitcoin supply
-       for (_, tlvs, max_htlc_candidate) in intermediate_nodes.iter() {
+       for node in intermediate_nodes.iter() {
                // The min htlc for an intermediate node is that node's min minus the fees charged by all of the
                // following hops for forwarding that min, since that fee amount will automatically be included
                // in the amount that this node receives and contribute towards reaching its min.
                htlc_minimum_msat = amt_to_forward_msat(
-                       core::cmp::max(tlvs.payment_constraints.htlc_minimum_msat, htlc_minimum_msat),
-                       &tlvs.payment_relay
+                       core::cmp::max(node.tlvs.payment_constraints.htlc_minimum_msat, htlc_minimum_msat),
+                       &node.tlvs.payment_relay
                ).unwrap_or(1); // If underflow occurs, we definitely reached this node's min
                htlc_maximum_msat = amt_to_forward_msat(
-                       core::cmp::min(*max_htlc_candidate, htlc_maximum_msat), &tlvs.payment_relay
+                       core::cmp::min(node.htlc_maximum_msat, htlc_maximum_msat), &node.tlvs.payment_relay
                ).ok_or(())?; // If underflow occurs, we cannot send to this hop without exceeding their max
        }
        htlc_minimum_msat = core::cmp::max(
@@ -257,7 +268,7 @@ impl_writeable_msg!(PaymentConstraints, {
 #[cfg(test)]
 mod tests {
        use bitcoin::secp256k1::PublicKey;
-       use crate::blinded_path::payment::{ForwardTlvs, ReceiveTlvs, PaymentConstraints, PaymentRelay};
+       use crate::blinded_path::payment::{ForwardNode, ForwardTlvs, ReceiveTlvs, PaymentConstraints, PaymentRelay};
        use crate::ln::PaymentSecret;
        use crate::ln::features::BlindedHopFeatures;
 
@@ -266,31 +277,39 @@ mod tests {
                // Taken from the spec example for aggregating blinded payment info. See
                // https://github.com/lightning/bolts/blob/master/proposals/route-blinding.md#blinded-payments
                let dummy_pk = PublicKey::from_slice(&[2; 33]).unwrap();
-               let intermediate_nodes = vec![(dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 144,
-                               fee_proportional_millionths: 500,
-                               fee_base_msat: 100,
-                       },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 100,
+               let intermediate_nodes = vec![ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 144,
+                                       fee_proportional_millionths: 500,
+                                       fee_base_msat: 100,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 100,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       features: BlindedHopFeatures::empty(),
-               }, u64::max_value()), (dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 144,
-                               fee_proportional_millionths: 500,
-                               fee_base_msat: 100,
+                       htlc_maximum_msat: u64::max_value(),
+               }, ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 144,
+                                       fee_proportional_millionths: 500,
+                                       fee_base_msat: 100,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 1_000,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 1_000,
-                       },
-                       features: BlindedHopFeatures::empty(),
-               }, u64::max_value())];
+                       htlc_maximum_msat: u64::max_value(),
+               }];
                let recv_tlvs = ReceiveTlvs {
                        payment_secret: PaymentSecret([0; 32]),
                        payment_constraints: PaymentConstraints {
@@ -329,31 +348,39 @@ mod tests {
                // If no hops charge fees, the htlc_minimum_msat should just be the maximum htlc_minimum_msat
                // along the path.
                let dummy_pk = PublicKey::from_slice(&[2; 33]).unwrap();
-               let intermediate_nodes = vec![(dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 0,
-                               fee_proportional_millionths: 0,
-                               fee_base_msat: 0,
+               let intermediate_nodes = vec![ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 0,
+                                       fee_proportional_millionths: 0,
+                                       fee_base_msat: 0,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 1,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 1,
-                       },
-                       features: BlindedHopFeatures::empty(),
-               }, u64::max_value()), (dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 0,
-                               fee_proportional_millionths: 0,
-                               fee_base_msat: 0,
-                       },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 2_000,
+                       htlc_maximum_msat: u64::max_value()
+               }, ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 0,
+                                       fee_proportional_millionths: 0,
+                                       fee_base_msat: 0,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 2_000,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       features: BlindedHopFeatures::empty(),
-               }, u64::max_value())];
+                       htlc_maximum_msat: u64::max_value()
+               }];
                let recv_tlvs = ReceiveTlvs {
                        payment_secret: PaymentSecret([0; 32]),
                        payment_constraints: PaymentConstraints {
@@ -371,31 +398,39 @@ mod tests {
                // Create a path with varying fees and htlc_mins, and make sure htlc_minimum_msat ends up as the
                // max (htlc_min - following_fees) along the path.
                let dummy_pk = PublicKey::from_slice(&[2; 33]).unwrap();
-               let intermediate_nodes = vec![(dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 0,
-                               fee_proportional_millionths: 500,
-                               fee_base_msat: 1_000,
-                       },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 5_000,
+               let intermediate_nodes = vec![ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 0,
+                                       fee_proportional_millionths: 500,
+                                       fee_base_msat: 1_000,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 5_000,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       features: BlindedHopFeatures::empty(),
-               }, u64::max_value()), (dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 0,
-                               fee_proportional_millionths: 500,
-                               fee_base_msat: 200,
+                       htlc_maximum_msat: u64::max_value()
+               }, ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 0,
+                                       fee_proportional_millionths: 500,
+                                       fee_base_msat: 200,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 2_000,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 2_000,
-                       },
-                       features: BlindedHopFeatures::empty(),
-               }, u64::max_value())];
+                       htlc_maximum_msat: u64::max_value()
+               }];
                let recv_tlvs = ReceiveTlvs {
                        payment_secret: PaymentSecret([0; 32]),
                        payment_constraints: PaymentConstraints {
@@ -417,31 +452,39 @@ mod tests {
                // Create a path with varying fees and `htlc_maximum_msat`s, and make sure the aggregated max
                // htlc ends up as the min (htlc_max - following_fees) along the path.
                let dummy_pk = PublicKey::from_slice(&[2; 33]).unwrap();
-               let intermediate_nodes = vec![(dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 0,
-                               fee_proportional_millionths: 500,
-                               fee_base_msat: 1_000,
+               let intermediate_nodes = vec![ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 0,
+                                       fee_proportional_millionths: 500,
+                                       fee_base_msat: 1_000,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 1,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 1,
-                       },
-                       features: BlindedHopFeatures::empty(),
-               }, 5_000), (dummy_pk, ForwardTlvs {
-                       short_channel_id: 0,
-                       payment_relay: PaymentRelay {
-                               cltv_expiry_delta: 0,
-                               fee_proportional_millionths: 500,
-                               fee_base_msat: 1,
-                       },
-                       payment_constraints: PaymentConstraints {
-                               max_cltv_expiry: 0,
-                               htlc_minimum_msat: 1,
+                       htlc_maximum_msat: 5_000,
+               }, ForwardNode {
+                       node_id: dummy_pk,
+                       tlvs: ForwardTlvs {
+                               short_channel_id: 0,
+                               payment_relay: PaymentRelay {
+                                       cltv_expiry_delta: 0,
+                                       fee_proportional_millionths: 500,
+                                       fee_base_msat: 1,
+                               },
+                               payment_constraints: PaymentConstraints {
+                                       max_cltv_expiry: 0,
+                                       htlc_minimum_msat: 1,
+                               },
+                               features: BlindedHopFeatures::empty(),
                        },
-                       features: BlindedHopFeatures::empty(),
-               }, 10_000)];
+                       htlc_maximum_msat: 10_000
+               }];
                let recv_tlvs = ReceiveTlvs {
                        payment_secret: PaymentSecret([0; 32]),
                        payment_constraints: PaymentConstraints {