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Move blinded path introduction point resolution to a helper method
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This marginally reduces the size of `get_route` by moving a the
blinded path introduction point resolution and blinded path checks
into a helper method.
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@TheBlueMatt
TheBlueMatt committed Jul 10, 2024
1 parent 5fb6637 commit 4f5e17b
Showing 1 changed file with 76 additions and 61 deletions.
137 changes: 76 additions & 61 deletions lightning/src/routing/router.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1635,6 +1635,79 @@ impl<'a> NodeCounters<'a> {
}
}

/// Calculates the introduction point for each blinded path in the given [`PaymentParameters`], if
/// they can be found.
fn calculate_blinded_path_intro_points<'a, L: Deref>(
payment_params: &PaymentParameters, node_counters: &'a NodeCounters,
network_graph: &ReadOnlyNetworkGraph, logger: &L, our_node_id: NodeId,
first_hop_targets: &HashMap<NodeId, (Vec<&ChannelDetails>, u32)>,
) -> Result<Vec<Option<(&'a NodeId, u32)>>, LightningError>
where L::Target: Logger {
let introduction_node_id_cache = payment_params.payee.blinded_route_hints().iter()
.map(|(_, path)| {
match &path.introduction_node {
IntroductionNode::NodeId(pubkey) => {
// Note that this will only return `Some` if the `pubkey` is somehow known to
// us (i.e. a channel counterparty or in the network graph).
node_counters.node_counter_from_id(&NodeId::from_pubkey(&pubkey))
},
IntroductionNode::DirectedShortChannelId(direction, scid) => {
path.public_introduction_node_id(network_graph)
.map(|node_id_ref| *node_id_ref)
.or_else(|| {
first_hop_targets.iter().find(|(_, (channels, _))|
channels
.iter()
.any(|details| Some(*scid) == details.get_outbound_payment_scid())
).map(|(cp, _)| direction.select_node_id(our_node_id, *cp))
})
.and_then(|node_id| node_counters.node_counter_from_id(&node_id))
},
}
})
.collect::<Vec<_>>();
match &payment_params.payee {
Payee::Clear { route_hints, node_id, .. } => {
for route in route_hints.iter() {
for hop in &route.0 {
if hop.src_node_id == *node_id {
return Err(LightningError {
err: "Route hint cannot have the payee as the source.".to_owned(),
action: ErrorAction::IgnoreError
});
}
}
}
},
Payee::Blinded { route_hints, .. } => {
if introduction_node_id_cache.iter().all(|info_opt| info_opt.map(|(a, _)| a) == Some(&our_node_id)) {
return Err(LightningError{err: "Cannot generate a route to blinded paths if we are the introduction node to all of them".to_owned(), action: ErrorAction::IgnoreError});
}
for ((_, blinded_path), info_opt) in route_hints.iter().zip(introduction_node_id_cache.iter()) {
if blinded_path.blinded_hops.len() == 0 {
return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
}
let introduction_node_id = match info_opt {
None => continue,
Some(info) => info.0,
};
if *introduction_node_id == our_node_id {
log_info!(logger, "Got blinded path with ourselves as the introduction node, ignoring");
} else if blinded_path.blinded_hops.len() == 1 &&
route_hints
.iter().zip(introduction_node_id_cache.iter())
.filter(|((_, p), _)| p.blinded_hops.len() == 1)
.any(|(_, iter_info_opt)| iter_info_opt.is_some() && iter_info_opt != info_opt)
{
return Err(LightningError{err: format!("1-hop blinded paths must all have matching introduction node ids"), action: ErrorAction::IgnoreError});
}
}
}
}

Ok(introduction_node_id_cache)
}

#[inline]
fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
Expand Down Expand Up @@ -2183,67 +2256,9 @@ where L::Target: Logger {

let node_counters = node_counter_builder.build();

let introduction_node_id_cache = payment_params.payee.blinded_route_hints().iter()
.map(|(_, path)| {
match &path.introduction_node {
IntroductionNode::NodeId(pubkey) => {
// Note that this will only return `Some` if the `pubkey` is somehow known to
// us (i.e. a channel counterparty or in the network graph).
node_counters.node_counter_from_id(&NodeId::from_pubkey(&pubkey))
},
IntroductionNode::DirectedShortChannelId(direction, scid) => {
path.public_introduction_node_id(network_graph)
.map(|node_id_ref| *node_id_ref)
.or_else(|| {
first_hop_targets.iter().find(|(_, (channels, _))|
channels
.iter()
.any(|details| Some(*scid) == details.get_outbound_payment_scid())
).map(|(cp, _)| direction.select_node_id(our_node_id, *cp))
})
.and_then(|node_id| node_counters.node_counter_from_id(&node_id))
},
}
})
.collect::<Vec<_>>();
match &payment_params.payee {
Payee::Clear { route_hints, node_id, .. } => {
for route in route_hints.iter() {
for hop in &route.0 {
if hop.src_node_id == *node_id {
return Err(LightningError {
err: "Route hint cannot have the payee as the source.".to_owned(),
action: ErrorAction::IgnoreError
});
}
}
}
},
Payee::Blinded { route_hints, .. } => {
if introduction_node_id_cache.iter().all(|info_opt| info_opt.map(|(a, _)| a) == Some(&our_node_id)) {
return Err(LightningError{err: "Cannot generate a route to blinded paths if we are the introduction node to all of them".to_owned(), action: ErrorAction::IgnoreError});
}
for ((_, blinded_path), info_opt) in route_hints.iter().zip(introduction_node_id_cache.iter()) {
if blinded_path.blinded_hops.len() == 0 {
return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
}
let introduction_node_id = match info_opt {
None => continue,
Some(info) => info.0,
};
if *introduction_node_id == our_node_id {
log_info!(logger, "Got blinded path with ourselves as the introduction node, ignoring");
} else if blinded_path.blinded_hops.len() == 1 &&
route_hints
.iter().zip(introduction_node_id_cache.iter())
.filter(|((_, p), _)| p.blinded_hops.len() == 1)
.any(|(_, iter_info_opt)| iter_info_opt.is_some() && iter_info_opt != info_opt)
{
return Err(LightningError{err: format!("1-hop blinded paths must all have matching introduction node ids"), action: ErrorAction::IgnoreError});
}
}
}
}
let introduction_node_id_cache = calculate_blinded_path_intro_points(
&payment_params, &node_counters, network_graph, &logger, our_node_id, &first_hop_targets,
)?;

// The main heap containing all candidate next-hops sorted by their score (max(fee,
// htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
Expand Down

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