Add MPP receive timeout handling
authorDuncan Dean <duncangleeddean@gmail.com>
Thu, 3 Mar 2022 19:06:40 +0000 (21:06 +0200)
committerDuncan Dean <duncangleeddean@gmail.com>
Tue, 22 Mar 2022 18:06:42 +0000 (20:06 +0200)
lightning/src/ln/channelmanager.rs
lightning/src/ln/payment_tests.rs

index 10404195c955325ff33e6e9e2b07be87c2e51c8a..82dec03bbfbc8783cd0469c7300d819d92daa41b 100644 (file)
@@ -441,6 +441,7 @@ struct ClaimableHTLC {
        cltv_expiry: u32,
        value: u64,
        onion_payload: OnionPayload,
+       timer_ticks: u8,
 }
 
 /// A payment identifier used to uniquely identify a payment to LDK.
@@ -1148,6 +1149,9 @@ const CHECK_CLTV_EXPIRY_SANITY_2: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_G
 /// pending HTLCs in flight.
 pub(crate) const PAYMENT_EXPIRY_BLOCKS: u32 = 3;
 
+/// The number of ticks of [`ChannelManager::timer_tick_occurred`] until expiry of incomplete MPPs
+pub(crate) const MPP_TIMEOUT_TICKS: u8 = 3;
+
 /// Information needed for constructing an invoice route hint for this channel.
 #[derive(Clone, Debug, PartialEq)]
 pub struct CounterpartyForwardingInfo {
@@ -3326,6 +3330,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                                phantom_shared_secret,
                                                                        },
                                                                        value: amt_to_forward,
+                                                                       timer_ticks: 0,
                                                                        cltv_expiry,
                                                                        onion_payload,
                                                                };
@@ -3620,6 +3625,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        let new_feerate = self.fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 
                        let mut handle_errors = Vec::new();
+                       let mut timed_out_mpp_htlcs = Vec::new();
                        {
                                let mut channel_state_lock = self.channel_state.lock().unwrap();
                                let channel_state = &mut *channel_state_lock;
@@ -3668,6 +3674,32 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 
                                        true
                                });
+
+                               channel_state.claimable_htlcs.retain(|payment_hash, htlcs| {
+                                       if htlcs.is_empty() {
+                                               // This should be unreachable
+                                               debug_assert!(false);
+                                               return false;
+                                       }
+                                       if let OnionPayload::Invoice(ref final_hop_data) = htlcs[0].onion_payload {
+                                               // Check if we've received all the parts we need for an MPP (the value of the parts adds to total_msat).
+                                               // In this case we're not going to handle any timeouts of the parts here.
+                                               if final_hop_data.total_msat == htlcs.iter().fold(0, |total, htlc| total + htlc.value) {
+                                                       return true;
+                                               } else if htlcs.into_iter().any(|htlc| {
+                                                       htlc.timer_ticks += 1;
+                                                       return htlc.timer_ticks >= MPP_TIMEOUT_TICKS
+                                               }) {
+                                                       timed_out_mpp_htlcs.extend(htlcs.into_iter().map(|htlc| (htlc.prev_hop.clone(), payment_hash.clone())));
+                                                       return false;
+                                               }
+                                       }
+                                       true
+                               });
+                       }
+
+                       for htlc_source in timed_out_mpp_htlcs.drain(..) {
+                               self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), HTLCSource::PreviousHopData(htlc_source.0), &htlc_source.1, HTLCFailReason::Reason { failure_code: 23, data: Vec::new() });
                        }
 
                        for (err, counterparty_node_id) in handle_errors.drain(..) {
@@ -6239,6 +6271,7 @@ impl Readable for ClaimableHTLC {
                };
                Ok(Self {
                        prev_hop: prev_hop.0.unwrap(),
+                       timer_ticks: 0,
                        value,
                        onion_payload,
                        cltv_expiry,
index bae9a2914fa8014a87b8a97015bc010d5580a366..26a0c19381343c365ba26ce9337965d4e804da71 100644 (file)
@@ -15,7 +15,7 @@ use chain::{ChannelMonitorUpdateErr, Confirm, Listen, Watch};
 use chain::channelmonitor::{ANTI_REORG_DELAY, ChannelMonitor, LATENCY_GRACE_PERIOD_BLOCKS};
 use chain::transaction::OutPoint;
 use chain::keysinterface::KeysInterface;
-use ln::channelmanager::{BREAKDOWN_TIMEOUT, ChannelManager, ChannelManagerReadArgs, PaymentId, PaymentSendFailure};
+use ln::channelmanager::{BREAKDOWN_TIMEOUT, ChannelManager, ChannelManagerReadArgs, MPP_TIMEOUT_TICKS, PaymentId, PaymentSendFailure};
 use ln::features::{InitFeatures, InvoiceFeatures};
 use ln::msgs;
 use ln::msgs::ChannelMessageHandler;
@@ -199,6 +199,78 @@ fn mpp_retry() {
        claim_payment_along_route(&nodes[0], &[&[&nodes[1], &nodes[3]], &[&nodes[2], &nodes[3]]], false, payment_preimage);
 }
 
+fn do_mpp_receive_timeout(send_partial_mpp: bool) {
+       let chanmon_cfgs = create_chanmon_cfgs(4);
+       let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, None, None]);
+       let nodes = create_network(4, &node_cfgs, &node_chanmgrs);
+
+       let chan_1_id = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known()).0.contents.short_channel_id;
+       let chan_2_id = create_announced_chan_between_nodes(&nodes, 0, 2, InitFeatures::known(), InitFeatures::known()).0.contents.short_channel_id;
+       let chan_3_id = create_announced_chan_between_nodes(&nodes, 1, 3, InitFeatures::known(), InitFeatures::known()).0.contents.short_channel_id;
+       let chan_4_id = create_announced_chan_between_nodes(&nodes, 2, 3, InitFeatures::known(), InitFeatures::known()).0.contents.short_channel_id;
+
+       let (mut route, payment_hash, payment_preimage, payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[3], 100_000);
+       let path = route.paths[0].clone();
+       route.paths.push(path);
+       route.paths[0][0].pubkey = nodes[1].node.get_our_node_id();
+       route.paths[0][0].short_channel_id = chan_1_id;
+       route.paths[0][1].short_channel_id = chan_3_id;
+       route.paths[1][0].pubkey = nodes[2].node.get_our_node_id();
+       route.paths[1][0].short_channel_id = chan_2_id;
+       route.paths[1][1].short_channel_id = chan_4_id;
+
+       // Initiate the MPP payment.
+       let _ = nodes[0].node.send_payment(&route, payment_hash, &Some(payment_secret)).unwrap();
+       check_added_monitors!(nodes[0], 2); // one monitor per path
+       let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+       assert_eq!(events.len(), 2);
+
+       // Pass half of the payment along the first path.
+       pass_along_path(&nodes[0], &[&nodes[1], &nodes[3]], 200_000, payment_hash, Some(payment_secret), events.remove(0), false, None);
+
+       if send_partial_mpp {
+               // Time out the partial MPP
+               for _ in 0..MPP_TIMEOUT_TICKS {
+                       nodes[3].node.timer_tick_occurred();
+               }
+
+               // Failed HTLC from node 3 -> 1
+               expect_pending_htlcs_forwardable!(nodes[3]);
+               let htlc_fail_updates_3_1 = get_htlc_update_msgs!(nodes[3], nodes[1].node.get_our_node_id());
+               assert_eq!(htlc_fail_updates_3_1.update_fail_htlcs.len(), 1);
+               nodes[1].node.handle_update_fail_htlc(&nodes[3].node.get_our_node_id(), &htlc_fail_updates_3_1.update_fail_htlcs[0]);
+               check_added_monitors!(nodes[3], 1);
+               commitment_signed_dance!(nodes[1], nodes[3], htlc_fail_updates_3_1.commitment_signed, false);
+
+               // Failed HTLC from node 1 -> 0
+               expect_pending_htlcs_forwardable!(nodes[1]);
+               let htlc_fail_updates_1_0 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+               assert_eq!(htlc_fail_updates_1_0.update_fail_htlcs.len(), 1);
+               nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &htlc_fail_updates_1_0.update_fail_htlcs[0]);
+               check_added_monitors!(nodes[1], 1);
+               commitment_signed_dance!(nodes[0], nodes[1], htlc_fail_updates_1_0.commitment_signed, false);
+
+               expect_payment_failed_conditions!(nodes[0], payment_hash, false, PaymentFailedConditions::new().mpp_parts_remain().expected_htlc_error_data(23, &[][..]));
+       } else {
+               // Pass half of the payment along the second path.
+               pass_along_path(&nodes[0], &[&nodes[2], &nodes[3]], 200_000, payment_hash, Some(payment_secret), events.remove(0), true, None);
+
+               // Even after MPP_TIMEOUT_TICKS we should not timeout the MPP if we have all the parts
+               for _ in 0..MPP_TIMEOUT_TICKS {
+                       nodes[3].node.timer_tick_occurred();
+               }
+
+               claim_payment_along_route(&nodes[0], &[&[&nodes[1], &nodes[3]], &[&nodes[2], &nodes[3]]], false, payment_preimage);
+       }
+}
+
+#[test]
+fn mpp_receive_timeout() {
+       do_mpp_receive_timeout(true);
+       do_mpp_receive_timeout(false);
+}
+
 #[test]
 fn retry_expired_payment() {
        let chanmon_cfgs = create_chanmon_cfgs(3);