]> git.bitcoin.ninja Git - rust-lightning/commitdiff
Allow failing back intercepted HTLCs
authorValentine Wallace <vwallace@protonmail.com>
Mon, 7 Nov 2022 16:16:49 +0000 (11:16 -0500)
committerValentine Wallace <vwallace@protonmail.com>
Wed, 30 Nov 2022 17:52:23 +0000 (12:52 -0500)
Co-authored-by: John Cantrell <johncantrell97@gmail.com>
Co-authored-by: Valentine Wallace <vwallace@protonmail.com>
lightning/src/ln/channelmanager.rs
lightning/src/ln/payment_tests.rs
lightning/src/util/events.rs

index de86a8e703c44ce59cfb8b5664412755f8d7d2f3..c4d90480eecd2baeaeca20fd23299b0de2a00d58 100644 (file)
@@ -3059,7 +3059,8 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
        ///
        /// To make use of intercepted HTLCs, use [`ChannelManager::get_intercept_scid`] to generate short
        /// channel id(s) to put in the receiver's invoice route hints. These route hints will signal to
-       /// LDK to generate an [`HTLCIntercepted`] event when it receives the forwarded HTLC.
+       /// LDK to generate an [`HTLCIntercepted`] event when it receives the forwarded HTLC, and this
+       /// method or [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to the event.
        ///
        /// Note that LDK does not enforce fee requirements in `amt_to_forward_msat`, and will not stop
        /// you from forwarding more than you received.
@@ -3102,6 +3103,35 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
                Ok(())
        }
 
+       /// Fails the intercepted HTLC indicated by intercept_id. Should only be called in response to
+       /// an [`HTLCIntercepted`] event. See [`ChannelManager::forward_intercepted_htlc`].
+       ///
+       /// [`HTLCIntercepted`]: events::Event::HTLCIntercepted
+       pub fn fail_intercepted_htlc(&self, intercept_id: InterceptId) -> Result<(), APIError> {
+               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
+
+               let payment = self.pending_intercepted_htlcs.lock().unwrap().remove(&intercept_id)
+                       .ok_or_else(|| APIError::APIMisuseError {
+                               err: format!("Payment with InterceptId {:?} not found", intercept_id)
+                       })?;
+
+               if let PendingHTLCRouting::Forward { short_channel_id, .. } = payment.forward_info.routing {
+                       let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
+                               short_channel_id: payment.prev_short_channel_id,
+                               outpoint: payment.prev_funding_outpoint,
+                               htlc_id: payment.prev_htlc_id,
+                               incoming_packet_shared_secret: payment.forward_info.incoming_shared_secret,
+                               phantom_shared_secret: None,
+                       });
+
+                       let failure_reason = HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() };
+                       let destination = HTLCDestination::UnknownNextHop { requested_forward_scid: short_channel_id };
+                       self.fail_htlc_backwards_internal(htlc_source, &payment.forward_info.payment_hash, failure_reason, destination);
+               } else { unreachable!() } // Only `PendingHTLCRouting::Forward`s are intercepted
+
+               Ok(())
+       }
+
        /// Processes HTLCs which are pending waiting on random forward delay.
        ///
        /// Should only really ever be called in response to a PendingHTLCsForwardable event.
index 4b2ed1f0d8ece388f849bf01a9946ecbbb76c45f..59f6909b837597cfec9c6a5bcf4d2dd17803505e 100644 (file)
@@ -1374,9 +1374,15 @@ fn test_holding_cell_inflight_htlcs() {
 }
 
 #[test]
-fn forward_intercepted_payment() {
+fn intercepted_payment() {
        // Test that detecting an intercept scid on payment forward will signal LDK to generate an
-       // intercept event, which the LSP can then use to open a JIT channel to forward the payment.
+       // intercept event, which the LSP can then use to either (a) open a JIT channel to forward the
+       // payment or (b) fail the payment.
+       do_test_intercepted_payment(false);
+       do_test_intercepted_payment(true);
+}
+
+fn do_test_intercepted_payment(fail_intercept: bool) {
        let chanmon_cfgs = create_chanmon_cfgs(3);
        let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
        let mut chan_config = test_default_channel_config();
@@ -1449,49 +1455,69 @@ fn forward_intercepted_payment() {
        let unknown_chan_id_err = nodes[1].node.forward_intercepted_htlc(intercept_id, &[42; 32], nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap_err();
        assert_eq!(unknown_chan_id_err , APIError::APIMisuseError { err: format!("Channel with id {:?} not found", [42; 32]) });
 
-       // Open the just-in-time channel so the payment can then be forwarded.
-       let (_, channel_id) = open_zero_conf_channel(&nodes[1], &nodes[2], None);
-
-       // Check for unknown intercept id error.
-       let unknown_intercept_id = InterceptId([42; 32]);
-       let unknown_intercept_id_err = nodes[1].node.forward_intercepted_htlc(unknown_intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap_err();
-       assert_eq!(unknown_intercept_id_err , APIError::APIMisuseError { err: format!("Payment with intercept id {:?} not found", unknown_intercept_id.0) });
-
-       // Finally, forward the intercepted payment through and claim it.
-       nodes[1].node.forward_intercepted_htlc(intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap();
-       expect_pending_htlcs_forwardable!(nodes[1]);
-
-       let payment_event = {
-               {
-                       let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
-                       assert_eq!(added_monitors.len(), 1);
-                       added_monitors.clear();
+       if fail_intercept {
+               // Ensure we can fail the intercepted payment back.
+               nodes[1].node.fail_intercepted_htlc(intercept_id).unwrap();
+               expect_pending_htlcs_forwardable_and_htlc_handling_failed_ignore!(nodes[1], vec![HTLCDestination::UnknownNextHop { requested_forward_scid: intercept_scid }]);
+               nodes[1].node.process_pending_htlc_forwards();
+               let update_fail = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+               check_added_monitors!(&nodes[1], 1);
+               assert!(update_fail.update_fail_htlcs.len() == 1);
+               let fail_msg = update_fail.update_fail_htlcs[0].clone();
+               nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
+               commitment_signed_dance!(nodes[0], nodes[1], update_fail.commitment_signed, false);
+
+               // Ensure the payment fails with the expected error.
+               let fail_conditions = PaymentFailedConditions::new()
+                       .blamed_scid(intercept_scid)
+                       .blamed_chan_closed(true)
+                       .expected_htlc_error_data(0x4000 | 10, &[]);
+               expect_payment_failed_conditions(&nodes[0], payment_hash, false, fail_conditions);
+       } else {
+               // Open the just-in-time channel so the payment can then be forwarded.
+               let (_, channel_id) = open_zero_conf_channel(&nodes[1], &nodes[2], None);
+
+               // Check for unknown intercept id error.
+               let unknown_intercept_id = InterceptId([42; 32]);
+               let unknown_intercept_id_err = nodes[1].node.forward_intercepted_htlc(unknown_intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap_err();
+               assert_eq!(unknown_intercept_id_err , APIError::APIMisuseError { err: format!("Payment with intercept id {:?} not found", unknown_intercept_id.0) });
+
+               // Finally, forward the intercepted payment through and claim it.
+               nodes[1].node.forward_intercepted_htlc(intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap();
+               expect_pending_htlcs_forwardable!(nodes[1]);
+
+               let payment_event = {
+                       {
+                               let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
+                               assert_eq!(added_monitors.len(), 1);
+                               added_monitors.clear();
+                       }
+                       let mut events = nodes[1].node.get_and_clear_pending_msg_events();
+                       assert_eq!(events.len(), 1);
+                       SendEvent::from_event(events.remove(0))
+               };
+               nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]);
+               commitment_signed_dance!(nodes[2], nodes[1], &payment_event.commitment_msg, false, true);
+               expect_pending_htlcs_forwardable!(nodes[2]);
+
+               let payment_preimage = nodes[2].node.get_payment_preimage(payment_hash, payment_secret).unwrap();
+               expect_payment_received!(&nodes[2], payment_hash, payment_secret, amt_msat, Some(payment_preimage), nodes[2].node.get_our_node_id());
+               do_claim_payment_along_route(&nodes[0], &vec!(&vec!(&nodes[1], &nodes[2])[..]), false, payment_preimage);
+               let events = nodes[0].node.get_and_clear_pending_events();
+               assert_eq!(events.len(), 2);
+               match events[0] {
+                       Event::PaymentSent { payment_preimage: ref ev_preimage, payment_hash: ref ev_hash, ref fee_paid_msat, .. } => {
+                               assert_eq!(payment_preimage, *ev_preimage);
+                               assert_eq!(payment_hash, *ev_hash);
+                               assert_eq!(fee_paid_msat, &Some(1000));
+                       },
+                       _ => panic!("Unexpected event")
+               }
+               match events[1] {
+                       Event::PaymentPathSuccessful { payment_hash: hash, .. } => {
+                               assert_eq!(hash, Some(payment_hash));
+                       },
+                       _ => panic!("Unexpected event")
                }
-               let mut events = nodes[1].node.get_and_clear_pending_msg_events();
-               assert_eq!(events.len(), 1);
-               SendEvent::from_event(events.remove(0))
-       };
-       nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]);
-       commitment_signed_dance!(nodes[2], nodes[1], &payment_event.commitment_msg, false, true);
-       expect_pending_htlcs_forwardable!(nodes[2]);
-
-       let payment_preimage = nodes[2].node.get_payment_preimage(payment_hash, payment_secret).unwrap();
-       expect_payment_received!(&nodes[2], payment_hash, payment_secret, amt_msat, Some(payment_preimage), nodes[2].node.get_our_node_id());
-       do_claim_payment_along_route(&nodes[0], &vec!(&vec!(&nodes[1], &nodes[2])[..]), false, payment_preimage);
-       let events = nodes[0].node.get_and_clear_pending_events();
-       assert_eq!(events.len(), 2);
-       match events[0] {
-               Event::PaymentSent { payment_preimage: ref ev_preimage, payment_hash: ref ev_hash, ref fee_paid_msat, .. } => {
-                       assert_eq!(payment_preimage, *ev_preimage);
-                       assert_eq!(payment_hash, *ev_hash);
-                       assert_eq!(fee_paid_msat, &Some(1000));
-               },
-               _ => panic!("Unexpected event")
-       }
-       match events[1] {
-               Event::PaymentPathSuccessful { payment_hash: hash, .. } => {
-                       assert_eq!(hash, Some(payment_hash));
-               },
-               _ => panic!("Unexpected event")
        }
 }
index d7e7bb1e37b317a0a750728fc4bf5290adb62370..e3e458cb9005c72af363e5eff7c1285f93c34898 100644 (file)
@@ -614,7 +614,13 @@ pub enum Event {
        /// you've encoded an intercept scid in the receiver's invoice route hints using
        /// [`ChannelManager::get_intercept_scid`].
        ///
+       /// [`ChannelManager::forward_intercepted_htlc`] or
+       /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
+       /// their docs for more information.
+       ///
        /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
+       /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
+       /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
        HTLCIntercepted {
                /// An id to help LDK identify which HTLC is being forwarded or failed.
                intercept_id: InterceptId,