]> git.bitcoin.ninja Git - rust-lightning/commitdiff
Merge pull request #316 from TheBlueMatt/2019-03-removed-reserve-check
authorMatt Corallo <649246+TheBlueMatt@users.noreply.github.com>
Mon, 25 Mar 2019 16:47:42 +0000 (12:47 -0400)
committerGitHub <noreply@github.com>
Mon, 25 Mar 2019 16:47:42 +0000 (12:47 -0400)
Fix remote reserve check with inbound claims-in-flight

src/ln/channel.rs
src/ln/functional_test_utils.rs
src/ln/functional_tests.rs

index 74728e3a96fd7f0290aae550c9909a8a4b977469..3745c11a1ae295b58ff8e2af23f43a52a9517f38 100644 (file)
@@ -881,9 +881,14 @@ impl Channel {
                        }
                }
 
-
                let value_to_self_msat: i64 = (self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset;
-               let value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000 - self.value_to_self_msat - remote_htlc_total_msat) as i64 - value_to_self_msat_offset;
+               assert!(value_to_self_msat >= 0);
+               // Note that in case they have several just-awaiting-last-RAA fulfills in-progress (ie
+               // AwaitingRemoteRevokeToRemove or AwaitingRemovedRemoteRevoke) we may have allowed them to
+               // "violate" their reserve value by couting those against it. Thus, we have to convert
+               // everything to i64 before subtracting as otherwise we can overflow.
+               let value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000) as i64 - (self.value_to_self_msat as i64) - (remote_htlc_total_msat as i64) - value_to_self_msat_offset;
+               assert!(value_to_remote_msat >= 0);
 
                #[cfg(debug_assertions)]
                {
@@ -1595,7 +1600,24 @@ impl Channel {
                // Check our_channel_reserve_satoshis (we're getting paid, so they have to at least meet
                // the reserve_satoshis we told them to always have as direct payment so that they lose
                // something if we punish them for broadcasting an old state).
-               if htlc_inbound_value_msat + msg.amount_msat + self.value_to_self_msat > (self.channel_value_satoshis - Channel::get_our_channel_reserve_satoshis(self.channel_value_satoshis)) * 1000 {
+               // Note that we don't really care about having a small/no to_remote output in our local
+               // commitment transactions, as the purpose of the channel reserve is to ensure we can
+               // punish *them* if they misbehave, so we discount any outbound HTLCs which will not be
+               // present in the next commitment transaction we send them (at least for fulfilled ones,
+               // failed ones won't modify value_to_self).
+               // Note that we will send HTLCs which another instance of rust-lightning would think
+               // violate the reserve value if we do not do this (as we forget inbound HTLCs from the
+               // Channel state once they will not be present in the next received commitment
+               // transaction).
+               let mut removed_outbound_total_msat = 0;
+               for ref htlc in self.pending_outbound_htlcs.iter() {
+                       if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(None) = htlc.state {
+                               removed_outbound_total_msat += htlc.amount_msat;
+                       } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) = htlc.state {
+                               removed_outbound_total_msat += htlc.amount_msat;
+                       }
+               }
+               if htlc_inbound_value_msat + msg.amount_msat + self.value_to_self_msat > (self.channel_value_satoshis - Channel::get_our_channel_reserve_satoshis(self.channel_value_satoshis)) * 1000 + removed_outbound_total_msat {
                        return Err(ChannelError::Close("Remote HTLC add would put them over their reserve value"));
                }
                if self.next_remote_htlc_id != msg.htlc_id {
index 1f11fe74bef235e92fe491cca95436c9551690e2..387c83761a69cb1ee063b90299174c873d6cda77 100644 (file)
@@ -542,6 +542,33 @@ macro_rules! expect_pending_htlcs_forwardable {
        }}
 }
 
+macro_rules! expect_payment_received {
+       ($node: expr, $expected_payment_hash: expr, $expected_recv_value: expr) => {
+               let events = $node.node.get_and_clear_pending_events();
+               assert_eq!(events.len(), 1);
+               match events[0] {
+                       Event::PaymentReceived { ref payment_hash, amt } => {
+                               assert_eq!($expected_payment_hash, *payment_hash);
+                               assert_eq!($expected_recv_value, amt);
+                       },
+                       _ => panic!("Unexpected event"),
+               }
+       }
+}
+
+macro_rules! expect_payment_sent {
+       ($node: expr, $expected_payment_preimage: expr) => {
+               let events = $node.node.get_and_clear_pending_events();
+               assert_eq!(events.len(), 1);
+               match events[0] {
+                       Event::PaymentSent { ref payment_preimage } => {
+                               assert_eq!($expected_payment_preimage, *payment_preimage);
+                       },
+                       _ => panic!("Unexpected event"),
+               }
+       }
+}
+
 pub fn send_along_route_with_hash(origin_node: &Node, route: Route, expected_route: &[&Node], recv_value: u64, our_payment_hash: PaymentHash) {
        let mut payment_event = {
                origin_node.node.send_payment(route, our_payment_hash).unwrap();
@@ -664,14 +691,7 @@ pub fn claim_payment_along_route(origin_node: &Node, expected_route: &[&Node], s
 
        if !skip_last {
                last_update_fulfill_dance!(origin_node, expected_route.first().unwrap());
-               let events = origin_node.node.get_and_clear_pending_events();
-               assert_eq!(events.len(), 1);
-               match events[0] {
-                       Event::PaymentSent { payment_preimage } => {
-                               assert_eq!(payment_preimage, our_payment_preimage);
-                       },
-                       _ => panic!("Unexpected event"),
-               }
+               expect_payment_sent!(origin_node, our_payment_preimage);
        }
 }
 
@@ -935,20 +955,6 @@ pub fn get_announce_close_broadcast_events(nodes: &Vec<Node>, a: usize, b: usize
        }
 }
 
-macro_rules! expect_payment_received {
-       ($node: expr, $expected_payment_hash: expr, $expected_recv_value: expr) => {
-               let events = $node.node.get_and_clear_pending_events();
-               assert_eq!(events.len(), 1);
-               match events[0] {
-                       Event::PaymentReceived { ref payment_hash, amt } => {
-                               assert_eq!($expected_payment_hash, *payment_hash);
-                               assert_eq!($expected_recv_value, amt);
-                       },
-                       _ => panic!("Unexpected event"),
-               }
-       }
-}
-
 macro_rules! get_channel_value_stat {
        ($node: expr, $channel_id: expr) => {{
                let chan_lock = $node.node.channel_state.lock().unwrap();
index 049777dad46bd76c41a4dbab13b0225e79007a51..0e82b4e696b91084068b156c9dc0cac9e9cae55f 100644 (file)
@@ -1450,6 +1450,153 @@ fn channel_reserve_test() {
        do_channel_reserve_test(true);
 }
 
+#[test]
+fn channel_reserve_in_flight_removes() {
+       // In cases where one side claims an HTLC, it thinks it has additional available funds that it
+       // can send to its counterparty, but due to update ordering, the other side may not yet have
+       // considered those HTLCs fully removed.
+       // This tests that we don't count HTLCs which will not be included in the next remote
+       // commitment transaction towards the reserve value (as it implies no commitment transaction
+       // will be generated which violates the remote reserve value).
+       // This was broken previously, and discovered by the chanmon_fail_consistency fuzz test.
+       // To test this we:
+       //  * route two HTLCs from A to B (note that, at a high level, this test is checking that, when
+       //    you consider the values of both of these HTLCs, B may not send an HTLC back to A, but if
+       //    you only consider the value of the first HTLC, it may not),
+       //  * start routing a third HTLC from A to B,
+       //  * claim the first two HTLCs (though B will generate an update_fulfill for one, and put
+       //    the other claim in its holding cell, as it immediately goes into AwaitingRAA),
+       //  * deliver the first fulfill from B
+       //  * deliver the update_add and an RAA from A, resulting in B freeing the second holding cell
+       //    claim,
+       //  * deliver A's response CS and RAA.
+       //    This results in A having the second HTLC in AwaitingRemovedRemoteRevoke, but B having
+       //    removed it fully. B now has the push_msat plus the first two HTLCs in value.
+       //  * Now B happily sends another HTLC, potentially violating its reserve value from A's point
+       //    of view (if A counts the AwaitingRemovedRemoteRevoke HTLC).
+       let mut nodes = create_network(2);
+       let chan_1 = create_announced_chan_between_nodes(&nodes, 0, 1);
+
+       let b_chan_values = get_channel_value_stat!(nodes[1], chan_1.2);
+       // Route the first two HTLCs.
+       let (payment_preimage_1, _) = route_payment(&nodes[0], &[&nodes[1]], b_chan_values.channel_reserve_msat - b_chan_values.value_to_self_msat - 10000);
+       let (payment_preimage_2, _) = route_payment(&nodes[0], &[&nodes[1]], 20000);
+
+       // Start routing the third HTLC (this is just used to get everyone in the right state).
+       let (payment_preimage_3, payment_hash_3) = get_payment_preimage_hash!(nodes[0]);
+       let send_1 = {
+               let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 100000, TEST_FINAL_CLTV).unwrap();
+               nodes[0].node.send_payment(route, payment_hash_3).unwrap();
+               check_added_monitors!(nodes[0], 1);
+               let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+               assert_eq!(events.len(), 1);
+               SendEvent::from_event(events.remove(0))
+       };
+
+       // Now claim both of the first two HTLCs on B's end, putting B in AwaitingRAA and generating an
+       // initial fulfill/CS.
+       assert!(nodes[1].node.claim_funds(payment_preimage_1));
+       check_added_monitors!(nodes[1], 1);
+       let bs_removes = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+       // This claim goes in B's holding cell, allowing us to have a pending B->A RAA which does not
+       // remove the second HTLC when we send the HTLC back from B to A.
+       assert!(nodes[1].node.claim_funds(payment_preimage_2));
+       check_added_monitors!(nodes[1], 1);
+       assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
+
+       nodes[0].node.handle_update_fulfill_htlc(&nodes[1].node.get_our_node_id(), &bs_removes.update_fulfill_htlcs[0]).unwrap();
+       nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_removes.commitment_signed).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let as_raa = get_event_msg!(nodes[0], MessageSendEvent::SendRevokeAndACK, nodes[1].node.get_our_node_id());
+       expect_payment_sent!(nodes[0], payment_preimage_1);
+
+       nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &send_1.msgs[0]).unwrap();
+       nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &send_1.commitment_msg).unwrap();
+       check_added_monitors!(nodes[1], 1);
+       // B is already AwaitingRAA, so cant generate a CS here
+       let bs_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+       nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_raa).unwrap();
+       check_added_monitors!(nodes[1], 1);
+       let bs_cs = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+       nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_raa).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let as_cs = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+
+       nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_cs.commitment_signed).unwrap();
+       check_added_monitors!(nodes[1], 1);
+       let bs_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+       // The second HTLCis removed, but as A is in AwaitingRAA it can't generate a CS here, so the
+       // RAA that B generated above doesn't fully resolve the second HTLC from A's point of view.
+       // However, the RAA A generates here *does* fully resolve the HTLC from B's point of view (as A
+       // can no longer broadcast a commitment transaction with it and B has the preimage so can go
+       // on-chain as necessary).
+       nodes[0].node.handle_update_fulfill_htlc(&nodes[1].node.get_our_node_id(), &bs_cs.update_fulfill_htlcs[0]).unwrap();
+       nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_cs.commitment_signed).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let as_raa = get_event_msg!(nodes[0], MessageSendEvent::SendRevokeAndACK, nodes[1].node.get_our_node_id());
+       expect_payment_sent!(nodes[0], payment_preimage_2);
+
+       nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_raa).unwrap();
+       check_added_monitors!(nodes[1], 1);
+       assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
+
+       expect_pending_htlcs_forwardable!(nodes[1]);
+       expect_payment_received!(nodes[1], payment_hash_3, 100000);
+
+       // Note that as this RAA was generated before the delivery of the update_fulfill it shouldn't
+       // resolve the second HTLC from A's point of view.
+       nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_raa).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let as_cs = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+
+       // Now that B doesn't have the second RAA anymore, but A still does, send a payment from B back
+       // to A to ensure that A doesn't count the almost-removed HTLC in update_add processing.
+       let (payment_preimage_4, payment_hash_4) = get_payment_preimage_hash!(nodes[1]);
+       let send_2 = {
+               let route = nodes[1].router.get_route(&nodes[0].node.get_our_node_id(), None, &[], 10000, TEST_FINAL_CLTV).unwrap();
+               nodes[1].node.send_payment(route, payment_hash_4).unwrap();
+               check_added_monitors!(nodes[1], 1);
+               let mut events = nodes[1].node.get_and_clear_pending_msg_events();
+               assert_eq!(events.len(), 1);
+               SendEvent::from_event(events.remove(0))
+       };
+
+       nodes[0].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &send_2.msgs[0]).unwrap();
+       nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &send_2.commitment_msg).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let as_raa = get_event_msg!(nodes[0], MessageSendEvent::SendRevokeAndACK, nodes[1].node.get_our_node_id());
+
+       // Now just resolve all the outstanding messages/HTLCs for completeness...
+
+       nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_cs.commitment_signed).unwrap();
+       check_added_monitors!(nodes[1], 1);
+       let bs_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+       nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_raa).unwrap();
+       check_added_monitors!(nodes[1], 1);
+
+       nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_raa).unwrap();
+       check_added_monitors!(nodes[0], 1);
+       let as_cs = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+
+       nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_cs.commitment_signed).unwrap();
+       check_added_monitors!(nodes[1], 1);
+       let bs_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+       nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_raa).unwrap();
+       check_added_monitors!(nodes[0], 1);
+
+       expect_pending_htlcs_forwardable!(nodes[0]);
+       expect_payment_received!(nodes[0], payment_hash_4, 10000);
+
+       claim_payment(&nodes[1], &[&nodes[0]], payment_preimage_4);
+       claim_payment(&nodes[0], &[&nodes[1]], payment_preimage_3);
+}
+
 #[test]
 fn channel_monitor_network_test() {
        // Simple test which builds a network of ChannelManagers, connects them to each other, and