Test MPP to 3-hop blinded paths.

diff --git a/lightning/src/ln/blinded_payment_tests.rs b/lightning/src/ln/blinded_payment_tests.rs
index 267929517d228ff36bfaca3df58e7d3fc7ddf7e0..93b13538c1c6c282d450e31d4f3fc099343e5591 100644 (file)
--- a/lightning/src/ln/blinded_payment_tests.rs
+++ b/lightning/src/ln/blinded_payment_tests.rs
@@ -169,6 +169,70 @@ fn mpp_to_one_hop_blinded_path() {
        claim_payment_along_route(&nodes[0], expected_route, false, payment_preimage);
 }
 
+#[test]
+fn mpp_to_three_hop_blinded_paths() {
+       let chanmon_cfgs = create_chanmon_cfgs(6);
+       let node_cfgs = create_node_cfgs(6, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(6, &node_cfgs, &[None, None, None, None, None, None]);
+       let nodes = create_network(6, &node_cfgs, &node_chanmgrs);
+
+       // Create this network topology so node 0 MPP's over 2 3-hop blinded paths:
+       //     n1 -- n3
+       //    /        \
+       // n0           n5
+       //    \        /
+       //     n2 -- n4
+       create_announced_chan_between_nodes(&nodes, 0, 1);
+       create_announced_chan_between_nodes(&nodes, 0, 2);
+       let chan_upd_1_3 = create_announced_chan_between_nodes(&nodes, 1, 3).0.contents;
+       let chan_upd_2_4 = create_announced_chan_between_nodes(&nodes, 2, 4).0.contents;
+       let chan_upd_3_5 = create_announced_chan_between_nodes(&nodes, 3, 5).0.contents;
+       let chan_upd_4_5 = create_announced_chan_between_nodes(&nodes, 4, 5).0.contents;
+
+       let amt_msat = 15_000_000;
+       let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[5], Some(amt_msat), None);
+       let route_params = {
+               let path_1_params = get_blinded_route_parameters(
+                       amt_msat, payment_secret, vec![
+                               nodes[1].node.get_our_node_id(), nodes[3].node.get_our_node_id(),
+                               nodes[5].node.get_our_node_id()
+                       ], &[&chan_upd_1_3, &chan_upd_3_5], &chanmon_cfgs[5].keys_manager
+               );
+               let path_2_params = get_blinded_route_parameters(
+                       amt_msat, payment_secret, vec![
+                               nodes[2].node.get_our_node_id(), nodes[4].node.get_our_node_id(),
+                               nodes[5].node.get_our_node_id()
+                       ], &[&chan_upd_2_4, &chan_upd_4_5], &chanmon_cfgs[5].keys_manager
+               );
+               let pay_params = PaymentParameters::blinded(
+                       vec![
+                               path_1_params.payment_params.payee.blinded_route_hints()[0].clone(),
+                               path_2_params.payment_params.payee.blinded_route_hints()[0].clone()
+                       ]
+               )
+                       .with_bolt12_features(channelmanager::provided_bolt12_invoice_features(&UserConfig::default()))
+                       .unwrap();
+               RouteParameters::from_payment_params_and_value(pay_params, amt_msat)
+       };
+
+       nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(),
+               PaymentId(payment_hash.0), route_params, Retry::Attempts(0)).unwrap();
+       check_added_monitors(&nodes[0], 2);
+
+       let expected_route: &[&[&Node]] = &[&[&nodes[1], &nodes[3], &nodes[5]], &[&nodes[2], &nodes[4], &nodes[5]]];
+       let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+       assert_eq!(events.len(), 2);
+
+       let ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
+       pass_along_path(&nodes[0], expected_route[0], amt_msat, payment_hash.clone(),
+               Some(payment_secret), ev.clone(), false, None);
+
+       let ev = remove_first_msg_event_to_node(&nodes[2].node.get_our_node_id(), &mut events);
+       pass_along_path(&nodes[0], expected_route[1], amt_msat, payment_hash.clone(),
+               Some(payment_secret), ev.clone(), true, None);
+       claim_payment_along_route(&nodes[0], expected_route, false, payment_preimage);
+}
+
 enum ForwardCheckFail {
        // Fail a check on the inbound onion payload. In this case, we underflow when calculating the
        // outgoing cltv_expiry.

diff --git a/lightning/src/ln/functional_test_utils.rs b/lightning/src/ln/functional_test_utils.rs
index adf2768b4152700ed82172e9a44ab75c6c3475a2..d147924b0fe4e7f0cd9e75c227d6200ac1db064c 100644 (file)
--- a/lightning/src/ln/functional_test_utils.rs
+++ b/lightning/src/ln/functional_test_utils.rs
@@ -2690,8 +2690,12 @@ pub fn pass_claimed_payment_along_route<'a, 'b, 'c, 'd>(args: ClaimAlongRouteArg
                per_path_msgs.push(msgs_from_ev!(&events[0]));
        } else {
                for expected_path in expected_paths.iter() {
-                       // For MPP payments, we always want the message to the first node in the path.
-                       let ev = remove_first_msg_event_to_node(&expected_path[0].node.get_our_node_id(), &mut events);
+                       // For MPP payments, we want the fulfill message from the payee to the penultimate hop in the
+                       // path.
+                       let penultimate_hop_node_id = expected_path.iter().rev().skip(1).next()
+                               .map(|n| n.node.get_our_node_id())
+                               .unwrap_or(origin_node.node.get_our_node_id());
+                       let ev = remove_first_msg_event_to_node(&penultimate_hop_node_id, &mut events);
                        per_path_msgs.push(msgs_from_ev!(&ev));
                }
        }

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 8e59c9bd46f5ff5edeed994adb96d2667a0acfc3..8d37182266b11debdda0d96787358c36c87dcd59 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -986,7 +986,7 @@ impl Payee {
                        _ => None,
                }
        }
-       fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
+       pub(crate) fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
                match self {
                        Self::Blinded { route_hints, .. } => &route_hints[..],
                        Self::Clear { .. } => &[]