@@ -1732,6 +1732,133 @@ fn do_test_intercepted_payment(test: InterceptTest) {
17321732 }
17331733}
17341734
1735+ #[ test]
1736+ fn accept_underpaying_htlcs_config ( ) {
1737+ do_accept_underpaying_htlcs_config ( 1 ) ;
1738+ do_accept_underpaying_htlcs_config ( 2 ) ;
1739+ do_accept_underpaying_htlcs_config ( 3 ) ;
1740+ }
1741+
1742+ fn do_accept_underpaying_htlcs_config ( num_mpp_parts : usize ) {
1743+ let chanmon_cfgs = create_chanmon_cfgs ( 3 ) ;
1744+ let node_cfgs = create_node_cfgs ( 3 , & chanmon_cfgs) ;
1745+ let mut intercept_forwards_config = test_default_channel_config ( ) ;
1746+ intercept_forwards_config. accept_intercept_htlcs = true ;
1747+ let mut underpay_config = test_default_channel_config ( ) ;
1748+ underpay_config. channel_config . accept_underpaying_htlcs = true ;
1749+ let node_chanmgrs = create_node_chanmgrs ( 3 , & node_cfgs, & [ None , Some ( intercept_forwards_config) , Some ( underpay_config) ] ) ;
1750+ let nodes = create_network ( 3 , & node_cfgs, & node_chanmgrs) ;
1751+
1752+ let mut chan_ids = Vec :: new ( ) ;
1753+ for _ in 0 ..num_mpp_parts {
1754+ let _ = create_announced_chan_between_nodes_with_value ( & nodes, 0 , 1 , 10_000 , 0 ) ;
1755+ let channel_id = create_unannounced_chan_between_nodes_with_value ( & nodes, 1 , 2 , 2_000_000 , 0 ) . 0 . channel_id ;
1756+ chan_ids. push ( channel_id) ;
1757+ }
1758+
1759+ // Send the initial payment.
1760+ let amt_msat = 900_000 ;
1761+ let skimmed_fee_msat = 20 ;
1762+ let mut route_hints = Vec :: new ( ) ;
1763+ for _ in 0 ..num_mpp_parts {
1764+ route_hints. push ( RouteHint ( vec ! [ RouteHintHop {
1765+ src_node_id: nodes[ 1 ] . node. get_our_node_id( ) ,
1766+ short_channel_id: nodes[ 1 ] . node. get_intercept_scid( ) ,
1767+ fees: RoutingFees {
1768+ base_msat: 1000 ,
1769+ proportional_millionths: 0 ,
1770+ } ,
1771+ cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA ,
1772+ htlc_minimum_msat: None ,
1773+ htlc_maximum_msat: Some ( amt_msat / num_mpp_parts as u64 + 5 ) ,
1774+ } ] ) ) ;
1775+ }
1776+ let payment_params = PaymentParameters :: from_node_id ( nodes[ 2 ] . node . get_our_node_id ( ) , TEST_FINAL_CLTV )
1777+ . with_route_hints ( route_hints) . unwrap ( )
1778+ . with_bolt11_features ( nodes[ 2 ] . node . invoice_features ( ) ) . unwrap ( ) ;
1779+ let route_params = RouteParameters {
1780+ payment_params,
1781+ final_value_msat : amt_msat,
1782+ } ;
1783+ let ( payment_hash, payment_secret) = nodes[ 2 ] . node . create_inbound_payment ( Some ( amt_msat) , 60 * 60 , None ) . unwrap ( ) ;
1784+ nodes[ 0 ] . node . send_payment ( payment_hash, RecipientOnionFields :: secret_only ( payment_secret) ,
1785+ PaymentId ( payment_hash. 0 ) , route_params, Retry :: Attempts ( 0 ) ) . unwrap ( ) ;
1786+ check_added_monitors ! ( nodes[ 0 ] , num_mpp_parts) ; // one monitor per path
1787+ let mut events: Vec < SendEvent > = nodes[ 0 ] . node . get_and_clear_pending_msg_events ( ) . into_iter ( ) . map ( |e| SendEvent :: from_event ( e) ) . collect ( ) ;
1788+ assert_eq ! ( events. len( ) , num_mpp_parts) ;
1789+
1790+ // Forward the intercepted payments.
1791+ for ( idx, ev) in events. into_iter ( ) . enumerate ( ) {
1792+ nodes[ 1 ] . node . handle_update_add_htlc ( & nodes[ 0 ] . node . get_our_node_id ( ) , & ev. msgs [ 0 ] ) ;
1793+ do_commitment_signed_dance ( & nodes[ 1 ] , & nodes[ 0 ] , & ev. commitment_msg , false , true ) ;
1794+
1795+ let events = nodes[ 1 ] . node . get_and_clear_pending_events ( ) ;
1796+ assert_eq ! ( events. len( ) , 1 ) ;
1797+ let ( intercept_id, expected_outbound_amt_msat) = match events[ 0 ] {
1798+ crate :: events:: Event :: HTLCIntercepted {
1799+ intercept_id, expected_outbound_amount_msat, payment_hash : pmt_hash, ..
1800+ } => {
1801+ assert_eq ! ( pmt_hash, payment_hash) ;
1802+ ( intercept_id, expected_outbound_amount_msat)
1803+ } ,
1804+ _ => panic ! ( )
1805+ } ;
1806+ nodes[ 1 ] . node . forward_intercepted_htlc ( intercept_id, & chan_ids[ idx] ,
1807+ nodes[ 2 ] . node . get_our_node_id ( ) , expected_outbound_amt_msat - skimmed_fee_msat) . unwrap ( ) ;
1808+ expect_pending_htlcs_forwardable ! ( nodes[ 1 ] ) ;
1809+ let payment_event = {
1810+ {
1811+ let mut added_monitors = nodes[ 1 ] . chain_monitor . added_monitors . lock ( ) . unwrap ( ) ;
1812+ assert_eq ! ( added_monitors. len( ) , 1 ) ;
1813+ added_monitors. clear ( ) ;
1814+ }
1815+ let mut events = nodes[ 1 ] . node . get_and_clear_pending_msg_events ( ) ;
1816+ assert_eq ! ( events. len( ) , 1 ) ;
1817+ SendEvent :: from_event ( events. remove ( 0 ) )
1818+ } ;
1819+ nodes[ 2 ] . node . handle_update_add_htlc ( & nodes[ 1 ] . node . get_our_node_id ( ) , & payment_event. msgs [ 0 ] ) ;
1820+ do_commitment_signed_dance ( & nodes[ 2 ] , & nodes[ 1 ] , & payment_event. commitment_msg , false , true ) ;
1821+ if idx == num_mpp_parts - 1 {
1822+ expect_pending_htlcs_forwardable ! ( nodes[ 2 ] ) ;
1823+ }
1824+ }
1825+
1826+ // Claim the payment and check that the skimmed fee is as expected.
1827+ let payment_preimage = nodes[ 2 ] . node . get_payment_preimage ( payment_hash, payment_secret) . unwrap ( ) ;
1828+ let events = nodes[ 2 ] . node . get_and_clear_pending_events ( ) ;
1829+ assert_eq ! ( events. len( ) , 1 ) ;
1830+ match events[ 0 ] {
1831+ crate :: events:: Event :: PaymentClaimable {
1832+ ref payment_hash, ref purpose, amount_msat, counterparty_skimmed_fee_msat, receiver_node_id, ..
1833+ } => {
1834+ assert_eq ! ( payment_hash, payment_hash) ;
1835+ assert_eq ! ( amt_msat - skimmed_fee_msat * num_mpp_parts as u64 , amount_msat) ;
1836+ assert_eq ! ( skimmed_fee_msat * num_mpp_parts as u64 , counterparty_skimmed_fee_msat) ;
1837+ assert_eq ! ( nodes[ 2 ] . node. get_our_node_id( ) , receiver_node_id. unwrap( ) ) ;
1838+ match purpose {
1839+ crate :: events:: PaymentPurpose :: InvoicePayment { payment_preimage : ev_payment_preimage,
1840+ payment_secret : ev_payment_secret, .. } =>
1841+ {
1842+ assert_eq ! ( payment_preimage, ev_payment_preimage. unwrap( ) ) ;
1843+ assert_eq ! ( payment_secret, * ev_payment_secret) ;
1844+ } ,
1845+ _ => panic ! ( ) ,
1846+ }
1847+ } ,
1848+ _ => panic ! ( "Unexpected event" ) ,
1849+ }
1850+ let mut expected_paths_vecs = Vec :: new ( ) ;
1851+ let mut expected_paths = Vec :: new ( ) ;
1852+ for _ in 0 ..num_mpp_parts { expected_paths_vecs. push ( vec ! ( & nodes[ 1 ] , & nodes[ 2 ] ) ) ; }
1853+ for i in 0 ..num_mpp_parts { expected_paths. push ( & expected_paths_vecs[ i] [ ..] ) ; }
1854+ let total_fee_msat = do_claim_payment_along_route_with_extra_penultimate_hop_fees (
1855+ & nodes[ 0 ] , & expected_paths[ ..] , & vec ! [ skimmed_fee_msat as u32 ; num_mpp_parts] [ ..] , false ,
1856+ payment_preimage) ;
1857+ // The sender doesn't know that the penultimate hop took an extra fee.
1858+ expect_payment_sent ( & nodes[ 0 ] , payment_preimage,
1859+ Some ( Some ( total_fee_msat - skimmed_fee_msat * num_mpp_parts as u64 ) ) , true ) ;
1860+ }
1861+
17351862#[ derive( PartialEq ) ]
17361863enum AutoRetry {
17371864 Success ,
0 commit comments