Track the sender's skimmed fee in UpdateAddHTLC

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index e74dbe42a77d52d0ad65a5e4d179fb68f543ec29..e24fed12aa7985ce4a855f2ce65cc3a7e47c314b 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -3695,6 +3695,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                                        payment_hash: htlc.payment_hash,
                                        cltv_expiry: htlc.cltv_expiry,
                                        onion_routing_packet: (**onion_packet).clone(),
+                                       skimmed_fee_msat: None,
                                });
                        }
                }
@@ -5145,6 +5146,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                        payment_hash,
                        cltv_expiry,
                        onion_routing_packet,
+                       skimmed_fee_msat: None,
                };
                self.context.next_holder_htlc_id += 1;
 

diff --git a/lightning/src/ln/functional_tests.rs b/lightning/src/ln/functional_tests.rs
index f03ecd14f661bd575976f505d11ad061b0160057..63b3b2bb0a49d9ba661f00050ddb7c2c031ed098 100644 (file)
--- a/lightning/src/ln/functional_tests.rs
+++ b/lightning/src/ln/functional_tests.rs
@@ -1393,6 +1393,7 @@ fn test_fee_spike_violation_fails_htlc() {
                payment_hash: payment_hash,
                cltv_expiry: htlc_cltv,
                onion_routing_packet: onion_packet,
+               skimmed_fee_msat: None,
        };
 
        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &msg);
@@ -1582,6 +1583,7 @@ fn test_chan_reserve_violation_inbound_htlc_outbound_channel() {
                payment_hash: payment_hash,
                cltv_expiry: htlc_cltv,
                onion_routing_packet: onion_packet,
+               skimmed_fee_msat: None,
        };
 
        nodes[0].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &msg);
@@ -1758,6 +1760,7 @@ fn test_chan_reserve_violation_inbound_htlc_inbound_chan() {
                payment_hash: our_payment_hash_1,
                cltv_expiry: htlc_cltv,
                onion_routing_packet: onion_packet,
+               skimmed_fee_msat: None,
        };
 
        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &msg);
@@ -3410,6 +3413,7 @@ fn fail_backward_pending_htlc_upon_channel_failure() {
                        payment_hash,
                        cltv_expiry,
                        onion_routing_packet,
+                       skimmed_fee_msat: None,
                };
                nodes[0].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &update_add_htlc);
        }
@@ -6259,6 +6263,7 @@ fn test_update_add_htlc_bolt2_receiver_check_max_htlc_limit() {
                payment_hash: our_payment_hash,
                cltv_expiry: htlc_cltv,
                onion_routing_packet: onion_packet.clone(),
+               skimmed_fee_msat: None,
        };
 
        for i in 0..50 {

diff --git a/lightning/src/ln/msgs.rs b/lightning/src/ln/msgs.rs
index 3dd4a6da70ccda8bde8a2e22f50db9c12e12d9cd..672c6ae6e96e8387cd840ae97f19080a5d4d8016 100644 (file)
--- a/lightning/src/ln/msgs.rs
+++ b/lightning/src/ln/msgs.rs
@@ -610,6 +610,11 @@ pub struct UpdateAddHTLC {
        pub payment_hash: PaymentHash,
        /// The expiry height of the HTLC
        pub cltv_expiry: u32,
+       /// The extra fee skimmed by the sender of this message. See
+       /// [`ChannelConfig::accept_underpaying_htlcs`].
+       ///
+       /// [`ChannelConfig::accept_underpaying_htlcs`]: crate::util::config::ChannelConfig::accept_underpaying_htlcs
+       pub skimmed_fee_msat: Option<u64>,
        pub(crate) onion_routing_packet: OnionPacket,
 }
 
@@ -1903,8 +1908,10 @@ impl_writeable_msg!(UpdateAddHTLC, {
        amount_msat,
        payment_hash,
        cltv_expiry,
-       onion_routing_packet
-}, {});
+       onion_routing_packet,
+}, {
+       (65537, skimmed_fee_msat, option)
+});
 
 impl Readable for OnionMessage {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
@@ -3330,7 +3337,8 @@ mod tests {
                        amount_msat: 3608586615801332854,
                        payment_hash: PaymentHash([1; 32]),
                        cltv_expiry: 821716,
-                       onion_routing_packet
+                       onion_routing_packet,
+                       skimmed_fee_msat: None,
                };
                let encoded_value = update_add_htlc.encode();
                let target_value = hex::decode("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").unwrap();