From 59925c1fa0509cda696825d334237655a346f294 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Tue, 21 Sep 2021 18:09:15 +0000 Subject: [PATCH] Fix a panic in Route's new fee-calculation methods and clean up This addresses Val's feedback on the new Route fee- and amount-calculation methods, including fixing the panic she identified and cleaning up various docs and comments. --- lightning/src/routing/router.rs | 40 +++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 14 deletions(-) diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs index 98b3d8f52..e60fd1ee1 100644 --- a/lightning/src/routing/router.rs +++ b/lightning/src/routing/router.rs @@ -72,21 +72,22 @@ pub struct Route { } impl Route { - /// Returns the total amount of fees paid on this Route. - /// This doesn't include any extra payment made to the recipient, - /// which can happen in excess of the amount passed to `get_route`'s `final_value_msat`. + /// Returns the total amount of fees paid on this [`Route`]. + /// + /// This doesn't include any extra payment made to the recipient, which can happen in excess of + /// the amount passed to [`get_route`]'s `final_value_msat`. pub fn get_total_fees(&self) -> u64 { // Do not count last hop of each path since that's the full value of the payment return self.paths.iter() - .flat_map(|path| path.split_last().unwrap().1) + .flat_map(|path| path.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])) .map(|hop| &hop.fee_msat) .sum(); } - /// Returns the total amount paid on this Route, excluding the fees. + + /// Returns the total amount paid on this [`Route`], excluding the fees. pub fn get_total_amount(&self) -> u64 { return self.paths.iter() - .map(|path| path.split_last().unwrap().0) - .map(|hop| &hop.fee_msat) + .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0)) .sum(); } } @@ -4226,17 +4227,17 @@ mod tests { RouteHop { pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0 }, RouteHop { pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0 }, RouteHop { pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0 }, ]], }; @@ -4252,23 +4253,23 @@ mod tests { RouteHop { pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0 }, RouteHop { pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0 }, ],vec![ RouteHop { pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0 }, RouteHop { pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(), channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(), - short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually + short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0 }, ]], }; @@ -4277,6 +4278,17 @@ mod tests { assert_eq!(route.get_total_amount(), 300); } + #[test] + fn total_empty_route_no_panic() { + // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they + // would both panic if the route was completely empty. We test to ensure they return 0 + // here, even though its somewhat nonsensical as a route. + let route = Route { paths: Vec::new() }; + + assert_eq!(route.get_total_fees(), 0); + assert_eq!(route.get_total_amount(), 0); + } + #[cfg(not(feature = "no-std"))] pub(super) fn random_init_seed() -> u64 { // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG. -- 2.39.5