// The median hop CLTV expiry delta currently seen in the network.
const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
+/// Estimated maximum number of hops that can be included in a payment path. May be inaccurate if
+/// payment metadata, custom TLVs, or blinded paths are included in the payment.
// During routing, we only consider paths shorter than our maximum length estimate.
// In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
// field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
// (payment_secret and total_msat) = 93 bytes for the final hop.
// Since the length of the potentially included `payment_metadata` is unknown to us, we round
// down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
-const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
+pub const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
/// Information used to route a payment.
#[derive(Clone, Debug, Hash, PartialEq, Eq)]
/// Defaults to [`DEFAULT_MAX_PATH_COUNT`].
pub max_path_count: u8,
+ /// The maximum number of [`Path::hops`] in any returned path.
+ /// Defaults to [`MAX_PATH_LENGTH_ESTIMATE`].
+ pub max_path_length: u8,
+
/// Selects the maximum share of a channel's total capacity which will be sent over a channel,
/// as a power of 1/2. A higher value prefers to send the payment using more MPP parts whereas
/// a lower value prefers to send larger MPP parts, potentially saturating channels and
(8, *blinded_hints, optional_vec),
(9, self.payee.final_cltv_expiry_delta(), option),
(11, self.previously_failed_blinded_path_idxs, required_vec),
+ (13, self.max_path_length, required),
});
Ok(())
}
(8, blinded_route_hints, optional_vec),
(9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
(11, previously_failed_blinded_path_idxs, optional_vec),
+ (13, max_path_length, (default_value, MAX_PATH_LENGTH_ESTIMATE)),
});
let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
let payee = if blinded_route_hints.len() != 0 {
expiry_time,
previously_failed_channels: previously_failed_channels.unwrap_or(Vec::new()),
previously_failed_blinded_path_idxs: previously_failed_blinded_path_idxs.unwrap_or(Vec::new()),
+ max_path_length: _init_tlv_based_struct_field!(max_path_length, (default_value, unused)),
})
}
}
expiry_time: None,
max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
max_path_count: DEFAULT_MAX_PATH_COUNT,
+ max_path_length: MAX_PATH_LENGTH_ESTIMATE,
max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
previously_failed_channels: Vec::new(),
previously_failed_blinded_path_idxs: Vec::new(),
expiry_time: None,
max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
max_path_count: DEFAULT_MAX_PATH_COUNT,
+ max_path_length: MAX_PATH_LENGTH_ESTIMATE,
max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
previously_failed_channels: Vec::new(),
previously_failed_blinded_path_idxs: Vec::new(),
where L::Target: Logger {
let payment_params = &route_params.payment_params;
+ let max_path_length = core::cmp::min(payment_params.max_path_length, MAX_PATH_LENGTH_ESTIMATE);
let final_value_msat = route_params.final_value_msat;
// If we're routing to a blinded recipient, we won't have their node id. Therefore, keep the
// unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
// Verify the liquidity offered by this channel complies to the minimal contribution.
let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
// Do not consider candidate hops that would exceed the maximum path length.
- let path_length_to_node = $next_hops_path_length + 1;
- let exceeds_max_path_length = path_length_to_node > MAX_PATH_LENGTH_ESTIMATE;
+ let path_length_to_node = $next_hops_path_length
+ + if $candidate.blinded_hint_idx().is_some() { 0 } else { 1 };
+ let exceeds_max_path_length = path_length_to_node > max_path_length;
// Do not consider candidates that exceed the maximum total cltv expiry limit.
// In order to already account for some of the privacy enhancing random CLTV
};
let path_min = candidate.htlc_minimum_msat().saturating_add(
compute_fees_saturating(candidate.htlc_minimum_msat(), candidate.fees()));
- add_entry!(&first_hop_candidate, blinded_path_fee,
- path_contribution_msat, path_min, 0_u64, candidate.cltv_expiry_delta(),
- candidate.blinded_path().map_or(1, |bp| bp.blinded_hops.len() as u8));
+ add_entry!(&first_hop_candidate, blinded_path_fee, path_contribution_msat, path_min,
+ 0_u64, candidate.cltv_expiry_delta(), 0);
}
}
}
fn simple_route_test() {
let (secp_ctx, network_graph, _, _, logger) = build_graph();
let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
- let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
+ let mut payment_params = PaymentParameters::from_node_id(nodes[2], 42);
let scorer = ln_test_utils::TestScorer::new();
let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
let random_seed_bytes = keys_manager.get_secure_random_bytes();
assert_eq!(err, "Cannot send a payment of 0 msat");
} else { panic!(); }
- let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+ payment_params.max_path_length = 2;
+ let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
assert_eq!(route.paths[0].hops.len(), 2);
assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
+
+ route_params.payment_params.max_path_length = 1;
+ get_route(&our_id, &route_params, &network_graph.read_only(), None,
+ Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap_err();
}
#[test]
});
// If all the channels require some features we don't understand, route should fail
- let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+ let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
&route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
&Default::default(), &random_seed_bytes) {
// If we specify a channel to node7, that overrides our local channel view and that gets used
let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
+ route_params.payment_params.max_path_length = 2;
let route = get_route(&our_id, &route_params, &network_graph.read_only(),
Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
&Default::default(), &random_seed_bytes).unwrap();
} else { panic!(); }
}
- let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
+ let mut payment_params = PaymentParameters::from_node_id(nodes[6], 42)
.with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
+ payment_params.max_path_length = 5;
let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
let random_seed_bytes = keys_manager.get_secure_random_bytes();
// Test through channels 2, 3, 0xff00, 0xff01.
- // Test shows that multiple hop hints are considered.
+ // Test shows that multi-hop route hints are considered and factored correctly into the
+ // max path length.
// Disabling channels 6 & 7 by flags=2
update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
excess_data: Vec::new()
});
- let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+ let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
+ route_params.payment_params.max_path_length = 4;
let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
assert_eq!(route.paths[0].hops.len(), 4);
assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
+ route_params.payment_params.max_path_length = 3;
+ get_route(&our_id, &route_params, &network_graph.read_only(), None,
+ Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap_err();
}
#[test]
projects / rust-lightning / blobdiff