X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fblinded_path%2Fpayment.rs;h=106cd802caac2abb860a19ab0366eea69370bfd2;hb=ab4b87209886569ba94df10ee27dccf9c0562d05;hp=488bdfee6c2b05f98ce96048aba7430df3fb47d8;hpb=02990cad80c26df89ad691c98df979e9382f8e2f;p=rust-lightning diff --git a/lightning/src/blinded_path/payment.rs b/lightning/src/blinded_path/payment.rs index 488bdfee..106cd802 100644 --- a/lightning/src/blinded_path/payment.rs +++ b/lightning/src/blinded_path/payment.rs @@ -8,6 +8,7 @@ use crate::blinded_path::BlindedHop; use crate::blinded_path::utils; use crate::io; use crate::ln::PaymentSecret; +use crate::ln::channelmanager::CounterpartyForwardingInfo; use crate::ln::features::BlindedHopFeatures; use crate::ln::msgs::DecodeError; use crate::offers::invoice::BlindedPayInfo; @@ -16,28 +17,42 @@ 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 { /// The short channel id this payment should be forwarded out over. - short_channel_id: u64, + pub short_channel_id: u64, /// Payment parameters for relaying over [`Self::short_channel_id`]. - payment_relay: PaymentRelay, + pub payment_relay: PaymentRelay, /// Payment constraints for relaying over [`Self::short_channel_id`]. - payment_constraints: PaymentConstraints, + pub payment_constraints: PaymentConstraints, /// Supported and required features when relaying a payment onion containing this object's /// corresponding [`BlindedHop::encrypted_payload`]. /// /// [`BlindedHop::encrypted_payload`]: crate::blinded_path::BlindedHop::encrypted_payload - features: BlindedHopFeatures, + pub features: BlindedHopFeatures, } /// Data to construct a [`BlindedHop`] for receiving a payment. This payload is custom to LDK and /// may not be valid if received by another lightning implementation. +#[derive(Clone, Debug)] pub struct ReceiveTlvs { /// Used to authenticate the sender of a payment to the receiver and tie MPP HTLCs together. - payment_secret: PaymentSecret, + pub payment_secret: PaymentSecret, /// Constraints for the receiver of this payment. - payment_constraints: PaymentConstraints, + pub payment_constraints: PaymentConstraints, } /// Data to construct a [`BlindedHop`] for sending a payment over. @@ -59,47 +74,71 @@ enum BlindedPaymentTlvsRef<'a> { /// Parameters for relaying over a given [`BlindedHop`]. /// /// [`BlindedHop`]: crate::blinded_path::BlindedHop +#[derive(Clone, Debug)] pub struct PaymentRelay { /// Number of blocks subtracted from an incoming HTLC's `cltv_expiry` for this [`BlindedHop`]. - /// - ///[`BlindedHop`]: crate::blinded_path::BlindedHop pub cltv_expiry_delta: u16, /// Liquidity fee charged (in millionths of the amount transferred) for relaying a payment over /// this [`BlindedHop`], (i.e., 10,000 is 1%). - /// - ///[`BlindedHop`]: crate::blinded_path::BlindedHop pub fee_proportional_millionths: u32, /// Base fee charged (in millisatoshi) for relaying a payment over this [`BlindedHop`]. - /// - ///[`BlindedHop`]: crate::blinded_path::BlindedHop pub fee_base_msat: u32, } /// Constraints for relaying over a given [`BlindedHop`]. /// /// [`BlindedHop`]: crate::blinded_path::BlindedHop +#[derive(Clone, Debug)] pub struct PaymentConstraints { - /// The maximum total CLTV delta that is acceptable when relaying a payment over this - /// [`BlindedHop`]. - /// - ///[`BlindedHop`]: crate::blinded_path::BlindedHop + /// The maximum total CLTV that is acceptable when relaying a payment over this [`BlindedHop`]. pub max_cltv_expiry: u32, /// The minimum value, in msat, that may be accepted by the node corresponding to this /// [`BlindedHop`]. pub htlc_minimum_msat: u64, } -impl_writeable_tlv_based!(ForwardTlvs, { - (2, short_channel_id, required), - (10, payment_relay, required), - (12, payment_constraints, required), - (14, features, required), -}); +impl TryFrom for PaymentRelay { + type Error = (); -impl_writeable_tlv_based!(ReceiveTlvs, { - (12, payment_constraints, required), - (65536, payment_secret, required), -}); + fn try_from(info: CounterpartyForwardingInfo) -> Result { + let CounterpartyForwardingInfo { + fee_base_msat, fee_proportional_millionths, cltv_expiry_delta + } = info; + + // Avoid exposing esoteric CLTV expiry deltas + let cltv_expiry_delta = match cltv_expiry_delta { + 0..=40 => 40, + 41..=80 => 80, + 81..=144 => 144, + 145..=216 => 216, + _ => return Err(()), + }; + + Ok(Self { cltv_expiry_delta, fee_proportional_millionths, fee_base_msat }) + } +} + +impl Writeable for ForwardTlvs { + fn write(&self, w: &mut W) -> Result<(), io::Error> { + encode_tlv_stream!(w, { + (2, self.short_channel_id, required), + (10, self.payment_relay, required), + (12, self.payment_constraints, required), + (14, self.features, required) + }); + Ok(()) + } +} + +impl Writeable for ReceiveTlvs { + fn write(&self, w: &mut W) -> Result<(), io::Error> { + encode_tlv_stream!(w, { + (12, self.payment_constraints, required), + (65536, self.payment_secret, required) + }); + Ok(()) + } +} impl<'a> Writeable for BlindedPaymentTlvsRef<'a> { fn write(&self, w: &mut W) -> Result<(), io::Error> { @@ -144,18 +183,18 @@ impl Readable for BlindedPaymentTlvs { /// Construct blinded payment hops for the given `intermediate_nodes` and payee info. pub(super) fn blinded_hops( - secp_ctx: &Secp256k1, intermediate_nodes: &[(PublicKey, ForwardTlvs)], + secp_ctx: &Secp256k1, intermediate_nodes: &[ForwardNode], payee_node_id: PublicKey, payee_tlvs: ReceiveTlvs, session_priv: &SecretKey ) -> Result, 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) } /// `None` if underflow occurs. -fn amt_to_forward_msat(inbound_amt_msat: u64, payment_relay: &PaymentRelay) -> Option { +pub(crate) fn amt_to_forward_msat(inbound_amt_msat: u64, payment_relay: &PaymentRelay) -> Option { let inbound_amt = inbound_amt_msat as u128; let base = payment_relay.fee_base_msat as u128; let prop = payment_relay.fee_proportional_millionths as u128; @@ -176,12 +215,13 @@ fn amt_to_forward_msat(inbound_amt_msat: u64, payment_relay: &PaymentRelay) -> O } pub(super) fn compute_payinfo( - intermediate_nodes: &[(PublicKey, ForwardTlvs)], payee_tlvs: &ReceiveTlvs + intermediate_nodes: &[ForwardNode], payee_tlvs: &ReceiveTlvs, payee_htlc_maximum_msat: u64, + min_final_cltv_expiry_delta: u16 ) -> Result { 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() { + let mut cltv_expiry_delta: u16 = min_final_cltv_expiry_delta; + 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(()) } @@ -207,25 +247,31 @@ pub(super) fn compute_payinfo( } let mut htlc_minimum_msat: u64 = 1; - for (_, tlvs) in intermediate_nodes.iter() { + let mut htlc_maximum_msat: u64 = 21_000_000 * 100_000_000 * 1_000; // Total bitcoin supply + 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(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( payee_tlvs.payment_constraints.htlc_minimum_msat, htlc_minimum_msat ); + htlc_maximum_msat = core::cmp::min(payee_htlc_maximum_msat, htlc_maximum_msat); + if htlc_maximum_msat < htlc_minimum_msat { return Err(()) } Ok(BlindedPayInfo { fee_base_msat: u32::try_from(curr_base_fee).map_err(|_| ())?, fee_proportional_millionths: u32::try_from(curr_prop_mil).map_err(|_| ())?, cltv_expiry_delta, htlc_minimum_msat, - htlc_maximum_msat: 21_000_000 * 100_000_000 * 1_000, // TODO + htlc_maximum_msat, features: BlindedHopFeatures::empty(), }) } @@ -244,40 +290,49 @@ 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; + use crate::ln::functional_test_utils::TEST_FINAL_CLTV; #[test] fn compute_payinfo() { // 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(), - }), (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(), - })]; + htlc_maximum_msat: u64::max_value(), + }]; let recv_tlvs = ReceiveTlvs { payment_secret: PaymentSecret([0; 32]), payment_constraints: PaymentConstraints { @@ -285,11 +340,13 @@ mod tests { htlc_minimum_msat: 1, }, }; - let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs).unwrap(); + let htlc_maximum_msat = 100_000; + let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs, htlc_maximum_msat, 12).unwrap(); assert_eq!(blinded_payinfo.fee_base_msat, 201); assert_eq!(blinded_payinfo.fee_proportional_millionths, 1001); - assert_eq!(blinded_payinfo.cltv_expiry_delta, 288); + assert_eq!(blinded_payinfo.cltv_expiry_delta, 300); assert_eq!(blinded_payinfo.htlc_minimum_msat, 900); + assert_eq!(blinded_payinfo.htlc_maximum_msat, htlc_maximum_msat); } #[test] @@ -301,11 +358,12 @@ mod tests { htlc_minimum_msat: 1, }, }; - let blinded_payinfo = super::compute_payinfo(&[], &recv_tlvs).unwrap(); + let blinded_payinfo = super::compute_payinfo(&[], &recv_tlvs, 4242, TEST_FINAL_CLTV as u16).unwrap(); assert_eq!(blinded_payinfo.fee_base_msat, 0); assert_eq!(blinded_payinfo.fee_proportional_millionths, 0); - assert_eq!(blinded_payinfo.cltv_expiry_delta, 0); + assert_eq!(blinded_payinfo.cltv_expiry_delta, TEST_FINAL_CLTV as u16); assert_eq!(blinded_payinfo.htlc_minimum_msat, 1); + assert_eq!(blinded_payinfo.htlc_maximum_msat, 4242); } #[test] @@ -313,31 +371,39 @@ 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, - }, - payment_constraints: PaymentConstraints { - max_cltv_expiry: 0, - htlc_minimum_msat: 1, + 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(), }, - features: BlindedHopFeatures::empty(), - }), (dummy_pk, ForwardTlvs { - short_channel_id: 0, - payment_relay: PaymentRelay { - cltv_expiry_delta: 0, - fee_proportional_millionths: 0, - fee_base_msat: 0, + 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(), }, - payment_constraints: PaymentConstraints { - max_cltv_expiry: 0, - htlc_minimum_msat: 2_000, - }, - features: BlindedHopFeatures::empty(), - })]; + htlc_maximum_msat: u64::max_value() + }]; let recv_tlvs = ReceiveTlvs { payment_secret: PaymentSecret([0; 32]), payment_constraints: PaymentConstraints { @@ -345,7 +411,8 @@ mod tests { htlc_minimum_msat: 3, }, }; - let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs).unwrap(); + let htlc_maximum_msat = 100_000; + let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs, htlc_maximum_msat, TEST_FINAL_CLTV as u16).unwrap(); assert_eq!(blinded_payinfo.htlc_minimum_msat, 2_000); } @@ -354,31 +421,93 @@ 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, + 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(), + }, + 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(), }, + htlc_maximum_msat: u64::max_value() + }]; + let recv_tlvs = ReceiveTlvs { + payment_secret: PaymentSecret([0; 32]), payment_constraints: PaymentConstraints { max_cltv_expiry: 0, - htlc_minimum_msat: 5_000, + htlc_minimum_msat: 1, }, - features: BlindedHopFeatures::empty(), - }), (dummy_pk, ForwardTlvs { - short_channel_id: 0, - payment_relay: PaymentRelay { - cltv_expiry_delta: 0, - fee_proportional_millionths: 500, - fee_base_msat: 200, + }; + let htlc_minimum_msat = 3798; + assert!(super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs, htlc_minimum_msat - 1, TEST_FINAL_CLTV as u16).is_err()); + + let htlc_maximum_msat = htlc_minimum_msat + 1; + let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs, htlc_maximum_msat, TEST_FINAL_CLTV as u16).unwrap(); + assert_eq!(blinded_payinfo.htlc_minimum_msat, htlc_minimum_msat); + assert_eq!(blinded_payinfo.htlc_maximum_msat, htlc_maximum_msat); + } + + #[test] + fn aggregated_htlc_max() { + // 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![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: 2_000, + 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(), - })]; + htlc_maximum_msat: 10_000 + }]; let recv_tlvs = ReceiveTlvs { payment_secret: PaymentSecret([0; 32]), payment_constraints: PaymentConstraints { @@ -386,8 +515,8 @@ mod tests { htlc_minimum_msat: 1, }, }; - let htlc_minimum_msat = 3798; - let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs).unwrap(); - assert_eq!(blinded_payinfo.htlc_minimum_msat, htlc_minimum_msat); + + let blinded_payinfo = super::compute_payinfo(&intermediate_nodes[..], &recv_tlvs, 10_000, TEST_FINAL_CLTV as u16).unwrap(); + assert_eq!(blinded_payinfo.htlc_maximum_msat, 3997); } }