Introduce `RouteParameters::max_total_routing_fee_msat`

[rust-lightning] / lightning / src / routing / router.rs

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 1758cbbf9c3eaae24151050f488c2524f43109da..dacc137ae8f536b6282f52576c7427b53908d825 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -409,6 +409,7 @@ impl Writeable for Route {
                        (1, self.route_params.as_ref().map(|p| &p.payment_params), option),
                        (2, blinded_tails, optional_vec),
                        (3, self.route_params.as_ref().map(|p| p.final_value_msat), option),
+                       (5, self.route_params.as_ref().map(|p| p.max_total_routing_fee_msat), option),
                });
                Ok(())
        }
@@ -436,6 +437,7 @@ impl Readable for Route {
                        (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
                        (2, blinded_tails, optional_vec),
                        (3, final_value_msat, option),
+                       (5, max_total_routing_fee_msat, option)
                });
                let blinded_tails = blinded_tails.unwrap_or(Vec::new());
                if blinded_tails.len() != 0 {
@@ -448,7 +450,7 @@ impl Readable for Route {
                // If we previously wrote the corresponding fields, reconstruct RouteParameters.
                let route_params = match (payment_params, final_value_msat) {
                        (Some(payment_params), Some(final_value_msat)) => {
-                               Some(RouteParameters { payment_params, final_value_msat })
+                               Some(RouteParameters { payment_params, final_value_msat, max_total_routing_fee_msat })
                        }
                        _ => None,
                };
@@ -467,12 +469,20 @@ pub struct RouteParameters {
 
        /// The amount in msats sent on the failed payment path.
        pub final_value_msat: u64,
+
+       /// The maximum total fees, in millisatoshi, that may accrue during route finding.
+       ///
+       /// This limit also applies to the total fees that may arise while retrying failed payment
+       /// paths.
+       ///
+       /// Default value: `None`
+       pub max_total_routing_fee_msat: Option<u64>,
 }
 
 impl RouteParameters {
        /// Constructs [`RouteParameters`] from the given [`PaymentParameters`] and a payment amount.
        pub fn from_payment_params_and_value(payment_params: PaymentParameters, final_value_msat: u64) -> Self {
-               Self { payment_params, final_value_msat }
+               Self { payment_params, final_value_msat, max_total_routing_fee_msat: None }
        }
 }
 
@@ -480,6 +490,7 @@ impl Writeable for RouteParameters {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                write_tlv_fields!(writer, {
                        (0, self.payment_params, required),
+                       (1, self.max_total_routing_fee_msat, option),
                        (2, self.final_value_msat, required),
                        // LDK versions prior to 0.0.114 had the `final_cltv_expiry_delta` parameter in
                        // `RouteParameters` directly. For compatibility, we write it here.
@@ -493,6 +504,7 @@ impl Readable for RouteParameters {
        fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payment_params, (required: ReadableArgs, 0)),
+                       (1, max_total_routing_fee_msat, option),
                        (2, final_value_msat, required),
                        (4, final_cltv_delta, option),
                });
@@ -505,6 +517,7 @@ impl Readable for RouteParameters {
                Ok(Self {
                        payment_params,
                        final_value_msat: final_value_msat.0.unwrap(),
+                       max_total_routing_fee_msat,
                })
        }
 }