package htlcswitch import ( "crypto/rand" "crypto/sha256" "fmt" "io" "io/ioutil" "reflect" "testing" "time" "github.com/btcsuite/btcutil" "github.com/davecgh/go-spew/spew" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/htlcswitch/hop" "github.com/lightningnetwork/lnd/lntypes" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/ticker" ) var zeroCircuit = channeldb.CircuitKey{} func genPreimage() ([32]byte, error) { var preimage [32]byte if _, err := io.ReadFull(rand.Reader, preimage[:]); err != nil { return preimage, err } return preimage, nil } // TestSwitchAddDuplicateLink tests that the switch will reject duplicate links // for both pending and live links. It also tests that we can successfully // add a link after having removed it. func TestSwitchAddDuplicateLink(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, _, aliceChanID, _ := genIDs() pendingChanID := lnwire.ShortChannelID{} aliceChannelLink := newMockChannelLink( s, chanID1, pendingChanID, alicePeer, false, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } // Alice should have a pending link, adding again should fail. if err := s.AddLink(aliceChannelLink); err == nil { t.Fatalf("adding duplicate link should have failed") } // Update the short chan id of the channel, so that the link goes live. aliceChannelLink.setLiveShortChanID(aliceChanID) err = s.UpdateShortChanID(chanID1) if err != nil { t.Fatalf("unable to update alice short_chan_id: %v", err) } // Alice should have a live link, adding again should fail. if err := s.AddLink(aliceChannelLink); err == nil { t.Fatalf("adding duplicate link should have failed") } // Remove the live link to ensure the indexes are cleared. s.RemoveLink(chanID1) // Alice has no links, adding should succeed. if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } } // TestSwitchHasActiveLink tests the behavior of HasActiveLink, and asserts that // it only returns true if a link's short channel id has confirmed (meaning the // channel is no longer pending) and it's EligibleToForward method returns true, // i.e. it has received FundingLocked from the remote peer. func TestSwitchHasActiveLink(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, _, aliceChanID, _ := genIDs() pendingChanID := lnwire.ShortChannelID{} aliceChannelLink := newMockChannelLink( s, chanID1, pendingChanID, alicePeer, false, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } // The link has been added, but it's still pending. HasActiveLink should // return false since the link has not been added to the linkIndex // containing live links. if s.HasActiveLink(chanID1) { t.Fatalf("link should not be active yet, still pending") } // Update the short chan id of the channel, so that the link goes live. aliceChannelLink.setLiveShortChanID(aliceChanID) err = s.UpdateShortChanID(chanID1) if err != nil { t.Fatalf("unable to update alice short_chan_id: %v", err) } // UpdateShortChanID will cause the mock link to become eligible to // forward. However, we can simulate the event where the short chan id // is confirmed, but funding locked has yet to be received by resetting // the mock link's eligibility to false. aliceChannelLink.eligible = false // Now, even though the link has been added to the linkIndex because the // short channel id has confirmed, we should still see HasActiveLink // fail because EligibleToForward should return false. if s.HasActiveLink(chanID1) { t.Fatalf("link should not be active yet, still ineligible") } // Finally, simulate the link receiving funding locked by setting its // eligibility to true. aliceChannelLink.eligible = true // The link should now be reported as active, since EligibleToForward // returns true and the link is in the linkIndex. if !s.HasActiveLink(chanID1) { t.Fatalf("link should not be active now") } } // TestSwitchSendPending checks the inability of htlc switch to forward adds // over pending links, and the UpdateShortChanID makes a pending link live. func TestSwitchSendPending(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, chanID2, aliceChanID, bobChanID := genIDs() pendingChanID := lnwire.ShortChannelID{} aliceChannelLink := newMockChannelLink( s, chanID1, pendingChanID, alicePeer, false, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should is being forwarded from Bob channel // link to Alice channel link. preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) packet := &htlcPacket{ incomingChanID: bobChanID, incomingHTLCID: 0, outgoingChanID: aliceChanID, obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } // Send the ADD packet, this should not be forwarded out to the link // since there are no eligible links. if err = s.ForwardPackets(nil, packet); err != nil { t.Fatal(err) } select { case p := <-bobChannelLink.packets: if p.linkFailure != nil { err = p.linkFailure } case <-time.After(time.Second): t.Fatal("no timely reply from switch") } linkErr, ok := err.(*LinkError) if !ok { t.Fatalf("expected link error, got: %T", err) } if linkErr.WireMessage().Code() != lnwire.CodeUnknownNextPeer { t.Fatalf("expected fail unknown next peer, got: %T", linkErr.WireMessage().Code()) } // No message should be sent, since the packet was failed. select { case <-aliceChannelLink.packets: t.Fatal("expected not to receive message") case <-time.After(time.Second): } // Since the packet should have been failed, there should be no active // circuits. if s.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } // Now, update Alice's link with her final short channel id. This should // move the link to the live state. aliceChannelLink.setLiveShortChanID(aliceChanID) err = s.UpdateShortChanID(chanID1) if err != nil { t.Fatalf("unable to update alice short_chan_id: %v", err) } // Increment the packet's HTLC index, so that it does not collide with // the prior attempt. packet.incomingHTLCID++ // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, packet); err != nil { t.Fatalf("unexpected forward failure: %v", err) } // Since Alice's link is now active, this packet should succeed. select { case <-aliceChannelLink.packets: case <-time.After(time.Second): t.Fatal("request was not propagated to alice") } } // TestSwitchForward checks the ability of htlc switch to forward add/settle // requests. func TestSwitchForward(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, chanID2, aliceChanID, bobChanID := genIDs() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) packet := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, packet); err != nil { t.Fatal(err) } select { case <-bobChannelLink.packets: if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumOpen() != 1 { t.Fatal("wrong amount of circuits") } if !s.IsForwardedHTLC(bobChannelLink.ShortChanID(), 0) { t.Fatal("htlc should be identified as forwarded") } // Create settle request pretending that bob link handled the add htlc // request and sent the htlc settle request back. This request should // be forwarder back to Alice link. packet = &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFulfillHTLC{ PaymentPreimage: preimage, }, } // Handle the request and checks that payment circuit works properly. if err := s.ForwardPackets(nil, packet); err != nil { t.Fatal(err) } select { case pkt := <-aliceChannelLink.packets: if err := aliceChannelLink.deleteCircuit(pkt); err != nil { t.Fatalf("unable to remove circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to channelPoint") } if s.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } } func TestSwitchForwardFailAfterFullAdd(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } tempPath, err := ioutil.TempDir("", "circuitdb") if err != nil { t.Fatalf("unable to temporary path: %v", err) } cdb, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to open channeldb: %v", err) } s, err := initSwitchWithDB(testStartingHeight, cdb) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } // Even though we intend to Stop s later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s.Stop() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) ogPacket := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } if s.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Pull packet from bob's link, but do not perform a full add. select { case packet := <-bobChannelLink.packets: // Complete the payment circuit and assign the outgoing htlc id // before restarting. if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 1 { t.Fatalf("wrong amount of circuits") } // Now we will restart bob, leaving the forwarding decision for this // htlc is in the half-added state. if err := s.Stop(); err != nil { t.Fatalf(err.Error()) } if err := cdb.Close(); err != nil { t.Fatalf(err.Error()) } cdb2, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to reopen channeldb: %v", err) } s2, err := initSwitchWithDB(testStartingHeight, cdb2) if err != nil { t.Fatalf("unable reinit switch: %v", err) } if err := s2.Start(); err != nil { t.Fatalf("unable to restart switch: %v", err) } // Even though we intend to Stop s2 later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s2.Stop() aliceChannelLink = newMockChannelLink( s2, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink = newMockChannelLink( s2, chanID2, bobChanID, bobPeer, true, ) if err := s2.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s2.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } if s2.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 1 { t.Fatalf("wrong amount of circuits") } // Craft a failure message from the remote peer. fail := &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFailHTLC{}, } // Send the fail packet from the remote peer through the switch. if err := s2.ForwardPackets(nil, fail); err != nil { t.Fatalf(err.Error()) } // Pull packet from alice's link, as it should have gone through // successfully. select { case pkt := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(pkt); err != nil { t.Fatalf("unable to remove circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } // Circuit map should be empty now. if s2.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Send the fail packet from the remote peer through the switch. if err := s.ForwardPackets(nil, fail); err != nil { t.Fatal(err) } select { case <-aliceChannelLink.packets: t.Fatalf("expected duplicate fail to not arrive at the destination") case <-time.After(time.Second): } } func TestSwitchForwardSettleAfterFullAdd(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } tempPath, err := ioutil.TempDir("", "circuitdb") if err != nil { t.Fatalf("unable to temporary path: %v", err) } cdb, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to open channeldb: %v", err) } s, err := initSwitchWithDB(testStartingHeight, cdb) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } // Even though we intend to Stop s later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s.Stop() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) ogPacket := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } if s.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Pull packet from bob's link, but do not perform a full add. select { case packet := <-bobChannelLink.packets: // Complete the payment circuit and assign the outgoing htlc id // before restarting. if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 1 { t.Fatalf("wrong amount of circuits") } // Now we will restart bob, leaving the forwarding decision for this // htlc is in the half-added state. if err := s.Stop(); err != nil { t.Fatalf(err.Error()) } if err := cdb.Close(); err != nil { t.Fatalf(err.Error()) } cdb2, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to reopen channeldb: %v", err) } s2, err := initSwitchWithDB(testStartingHeight, cdb2) if err != nil { t.Fatalf("unable reinit switch: %v", err) } if err := s2.Start(); err != nil { t.Fatalf("unable to restart switch: %v", err) } // Even though we intend to Stop s2 later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s2.Stop() aliceChannelLink = newMockChannelLink( s2, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink = newMockChannelLink( s2, chanID2, bobChanID, bobPeer, true, ) if err := s2.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s2.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } if s2.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 1 { t.Fatalf("wrong amount of circuits") } // Craft a settle message from the remote peer. settle := &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFulfillHTLC{ PaymentPreimage: preimage, }, } // Send the settle packet from the remote peer through the switch. if err := s2.ForwardPackets(nil, settle); err != nil { t.Fatalf(err.Error()) } // Pull packet from alice's link, as it should have gone through // successfully. select { case packet := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete circuit with in key=%s: %v", packet.inKey(), err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } // Circuit map should be empty now. if s2.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Send the settle packet again, which not arrive at destination. if err := s2.ForwardPackets(nil, settle); err != nil { t.Fatal(err) } select { case <-bobChannelLink.packets: t.Fatalf("expected duplicate fail to not arrive at the destination") case <-time.After(time.Second): } } func TestSwitchForwardDropAfterFullAdd(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } tempPath, err := ioutil.TempDir("", "circuitdb") if err != nil { t.Fatalf("unable to temporary path: %v", err) } cdb, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to open channeldb: %v", err) } s, err := initSwitchWithDB(testStartingHeight, cdb) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } // Even though we intend to Stop s later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s.Stop() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) ogPacket := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } if s.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of half circuits") } // Pull packet from bob's link, but do not perform a full add. select { case packet := <-bobChannelLink.packets: // Complete the payment circuit and assign the outgoing htlc id // before restarting. if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } // Now we will restart bob, leaving the forwarding decision for this // htlc is in the half-added state. if err := s.Stop(); err != nil { t.Fatalf(err.Error()) } if err := cdb.Close(); err != nil { t.Fatalf(err.Error()) } cdb2, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to reopen channeldb: %v", err) } s2, err := initSwitchWithDB(testStartingHeight, cdb2) if err != nil { t.Fatalf("unable reinit switch: %v", err) } if err := s2.Start(); err != nil { t.Fatalf("unable to restart switch: %v", err) } // Even though we intend to Stop s2 later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s2.Stop() aliceChannelLink = newMockChannelLink( s2, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink = newMockChannelLink( s2, chanID2, bobChanID, bobPeer, true, ) if err := s2.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s2.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } if s2.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 1 { t.Fatalf("wrong amount of half circuits") } // Resend the failed htlc. The packet will be dropped silently since the // switch will detect that it has been half added previously. if err := s2.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } // After detecting an incomplete forward, the fail packet should have // been returned to the sender. select { case <-aliceChannelLink.packets: t.Fatal("request should not have returned to source") case <-bobChannelLink.packets: t.Fatal("request should not have forwarded to destination") case <-time.After(time.Second): } } func TestSwitchForwardFailAfterHalfAdd(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } tempPath, err := ioutil.TempDir("", "circuitdb") if err != nil { t.Fatalf("unable to temporary path: %v", err) } cdb, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to open channeldb: %v", err) } s, err := initSwitchWithDB(testStartingHeight, cdb) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } // Even though we intend to Stop s later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s.Stop() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) ogPacket := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } if s.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of half circuits") } // Pull packet from bob's link, but do not perform a full add. select { case <-bobChannelLink.packets: case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } // Now we will restart bob, leaving the forwarding decision for this // htlc is in the half-added state. if err := s.Stop(); err != nil { t.Fatalf(err.Error()) } if err := cdb.Close(); err != nil { t.Fatalf(err.Error()) } cdb2, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to reopen channeldb: %v", err) } s2, err := initSwitchWithDB(testStartingHeight, cdb2) if err != nil { t.Fatalf("unable reinit switch: %v", err) } if err := s2.Start(); err != nil { t.Fatalf("unable to restart switch: %v", err) } // Even though we intend to Stop s2 later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s2.Stop() aliceChannelLink = newMockChannelLink( s2, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink = newMockChannelLink( s2, chanID2, bobChanID, bobPeer, true, ) if err := s2.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s2.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } if s2.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of half circuits") } // Resend the failed htlc, it should be returned to alice since the // switch will detect that it has been half added previously. err = s2.ForwardPackets(nil, ogPacket) if err != nil { t.Fatal(err) } // After detecting an incomplete forward, the fail packet should have // been returned to the sender. select { case pkt := <-aliceChannelLink.packets: linkErr := pkt.linkFailure if linkErr.FailureDetail != OutgoingFailureIncompleteForward { t.Fatalf("expected incomplete forward, got: %v", linkErr.FailureDetail) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } } // TestSwitchForwardCircuitPersistence checks the ability of htlc switch to // maintain the proper entries in the circuit map in the face of restarts. func TestSwitchForwardCircuitPersistence(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } tempPath, err := ioutil.TempDir("", "circuitdb") if err != nil { t.Fatalf("unable to temporary path: %v", err) } cdb, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to open channeldb: %v", err) } s, err := initSwitchWithDB(testStartingHeight, cdb) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } // Even though we intend to Stop s later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s.Stop() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) ogPacket := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } if s.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } // Retrieve packet from outgoing link and cache until after restart. var packet *htlcPacket select { case packet = <-bobChannelLink.packets: case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if err := s.Stop(); err != nil { t.Fatalf(err.Error()) } if err := cdb.Close(); err != nil { t.Fatalf(err.Error()) } cdb2, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to reopen channeldb: %v", err) } s2, err := initSwitchWithDB(testStartingHeight, cdb2) if err != nil { t.Fatalf("unable reinit switch: %v", err) } if err := s2.Start(); err != nil { t.Fatalf("unable to restart switch: %v", err) } // Even though we intend to Stop s2 later in the test, it is safe to // defer this Stop since its execution it is protected by an atomic // guard, guaranteeing it executes at most once. defer s2.Stop() aliceChannelLink = newMockChannelLink( s2, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink = newMockChannelLink( s2, chanID2, bobChanID, bobPeer, true, ) if err := s2.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s2.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } if s2.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of half circuits") } // Now that the switch has restarted, complete the payment circuit. if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } if s2.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s2.circuits.NumOpen() != 1 { t.Fatal("wrong amount of circuits") } // Create settle request pretending that bob link handled the add htlc // request and sent the htlc settle request back. This request should // be forwarder back to Alice link. ogPacket = &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFulfillHTLC{ PaymentPreimage: preimage, }, } // Handle the request and checks that payment circuit works properly. if err := s2.ForwardPackets(nil, ogPacket); err != nil { t.Fatal(err) } select { case packet = <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete circuit with in key=%s: %v", packet.inKey(), err) } case <-time.After(time.Second): t.Fatal("request was not propagated to channelPoint") } if s2.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits, want 1, got %d", s2.circuits.NumPending()) } if s2.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } if err := s2.Stop(); err != nil { t.Fatal(err) } if err := cdb2.Close(); err != nil { t.Fatalf(err.Error()) } cdb3, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to reopen channeldb: %v", err) } s3, err := initSwitchWithDB(testStartingHeight, cdb3) if err != nil { t.Fatalf("unable reinit switch: %v", err) } if err := s3.Start(); err != nil { t.Fatalf("unable to restart switch: %v", err) } defer s3.Stop() aliceChannelLink = newMockChannelLink( s3, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink = newMockChannelLink( s3, chanID2, bobChanID, bobPeer, true, ) if err := s3.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s3.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } if s3.circuits.NumPending() != 0 { t.Fatalf("wrong amount of half circuits") } if s3.circuits.NumOpen() != 0 { t.Fatalf("wrong amount of circuits") } } type multiHopFwdTest struct { name string eligible1, eligible2 bool failure1, failure2 *LinkError expectedReply lnwire.FailCode } // TestCircularForwards tests the allowing/disallowing of circular payments // through the same channel in the case where the switch is configured to allow // and disallow same channel circular forwards. func TestCircularForwards(t *testing.T) { chanID1, aliceChanID := genID() preimage := [sha256.Size]byte{1} hash := sha256.Sum256(preimage[:]) tests := []struct { name string allowCircularPayment bool expectedErr error }{ { name: "circular payment allowed", allowCircularPayment: true, expectedErr: nil, }, { name: "circular payment disallowed", allowCircularPayment: false, expectedErr: NewDetailedLinkError( lnwire.NewTemporaryChannelFailure(nil), OutgoingFailureCircularRoute, ), }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer func() { _ = s.Stop() }() // Set the switch to allow or disallow circular routes // according to the test's requirements. s.cfg.AllowCircularRoute = test.allowCircularPayment aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } // Create a new packet that loops through alice's link // in a circle. obfuscator := NewMockObfuscator() packet := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), outgoingChanID: aliceChannelLink.ShortChanID(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: hash, Amount: 1, }, obfuscator: obfuscator, } // Attempt to forward the packet and check for the expected // error. if err = s.ForwardPackets(nil, packet); err != nil { t.Fatal(err) } select { case p := <-aliceChannelLink.packets: if p.linkFailure != nil { err = p.linkFailure } case <-time.After(time.Second): t.Fatal("no timely reply from switch") } if !reflect.DeepEqual(err, test.expectedErr) { t.Fatalf("expected: %v, got: %v", test.expectedErr, err) } // Ensure that no circuits were opened. if s.circuits.NumOpen() > 0 { t.Fatal("do not expect any open circuits") } }) } } // TestCheckCircularForward tests the error returned by checkCircularForward // in cases where we allow and disallow same channel circular forwards. func TestCheckCircularForward(t *testing.T) { tests := []struct { name string // allowCircular determines whether we should allow circular // forwards. allowCircular bool // incomingLink is the link that the htlc arrived on. incomingLink lnwire.ShortChannelID // outgoingLink is the link that the htlc forward // is destined to leave on. outgoingLink lnwire.ShortChannelID // expectedErr is the error we expect to be returned. expectedErr *LinkError }{ { name: "not circular, allowed in config", allowCircular: true, incomingLink: lnwire.NewShortChanIDFromInt(123), outgoingLink: lnwire.NewShortChanIDFromInt(321), expectedErr: nil, }, { name: "not circular, not allowed in config", allowCircular: false, incomingLink: lnwire.NewShortChanIDFromInt(123), outgoingLink: lnwire.NewShortChanIDFromInt(321), expectedErr: nil, }, { name: "circular, allowed in config", allowCircular: true, incomingLink: lnwire.NewShortChanIDFromInt(123), outgoingLink: lnwire.NewShortChanIDFromInt(123), expectedErr: nil, }, { name: "circular, not allowed in config", allowCircular: false, incomingLink: lnwire.NewShortChanIDFromInt(123), outgoingLink: lnwire.NewShortChanIDFromInt(123), expectedErr: NewDetailedLinkError( lnwire.NewTemporaryChannelFailure(nil), OutgoingFailureCircularRoute, ), }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { t.Parallel() // Check for a circular forward, the hash passed can // be nil because it is only used for logging. err := checkCircularForward( test.incomingLink, test.outgoingLink, test.allowCircular, lntypes.Hash{}, ) if !reflect.DeepEqual(err, test.expectedErr) { t.Fatalf("expected: %v, got: %v", test.expectedErr, err) } }) } } // TestSkipIneligibleLinksMultiHopForward tests that if a multi-hop HTLC comes // along, then we won't attempt to froward it down al ink that isn't yet able // to forward any HTLC's. func TestSkipIneligibleLinksMultiHopForward(t *testing.T) { tests := []multiHopFwdTest{ // None of the channels is eligible. { name: "not eligible", expectedReply: lnwire.CodeUnknownNextPeer, }, // Channel one has a policy failure and the other channel isn't // available. { name: "policy fail", eligible1: true, failure1: NewLinkError( lnwire.NewFinalIncorrectCltvExpiry(0), ), expectedReply: lnwire.CodeFinalIncorrectCltvExpiry, }, // The requested channel is not eligible, but the packet is // forwarded through the other channel. { name: "non-strict success", eligible2: true, expectedReply: lnwire.CodeNone, }, // The requested channel has insufficient bandwidth and the // other channel's policy isn't satisfied. { name: "non-strict policy fail", eligible1: true, failure1: NewDetailedLinkError( lnwire.NewTemporaryChannelFailure(nil), OutgoingFailureInsufficientBalance, ), eligible2: true, failure2: NewLinkError( lnwire.NewFinalIncorrectCltvExpiry(0), ), expectedReply: lnwire.CodeTemporaryChannelFailure, }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { testSkipIneligibleLinksMultiHopForward(t, &test) }) } } // testSkipIneligibleLinksMultiHopForward tests that if a multi-hop HTLC comes // along, then we won't attempt to froward it down al ink that isn't yet able // to forward any HTLC's. func testSkipIneligibleLinksMultiHopForward(t *testing.T, testCase *multiHopFwdTest) { t.Parallel() var packet *htlcPacket alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, aliceChanID := genID() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) // We'll create a link for Bob, but mark the link as unable to forward // any new outgoing HTLC's. chanID2, bobChanID2 := genID() bobChannelLink1 := newMockChannelLink( s, chanID2, bobChanID2, bobPeer, testCase.eligible1, ) bobChannelLink1.checkHtlcForwardResult = testCase.failure1 chanID3, bobChanID3 := genID() bobChannelLink2 := newMockChannelLink( s, chanID3, bobChanID3, bobPeer, testCase.eligible2, ) bobChannelLink2.checkHtlcForwardResult = testCase.failure2 if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink1); err != nil { t.Fatalf("unable to add bob link: %v", err) } if err := s.AddLink(bobChannelLink2); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create a new packet that's destined for Bob as an incoming HTLC from // Alice. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) obfuscator := NewMockObfuscator() packet = &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink1.ShortChanID(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, obfuscator: obfuscator, } // The request to forward should fail as if err := s.ForwardPackets(nil, packet); err != nil { t.Fatal(err) } // We select from all links and extract the error if exists. // The packet must be selected but we don't always expect a link error. var linkError *LinkError select { case p := <-aliceChannelLink.packets: linkError = p.linkFailure case p := <-bobChannelLink1.packets: linkError = p.linkFailure case p := <-bobChannelLink2.packets: linkError = p.linkFailure case <-time.After(time.Second): t.Fatal("no timely reply from switch") } failure := obfuscator.(*mockObfuscator).failure if testCase.expectedReply == lnwire.CodeNone { if linkError != nil { t.Fatalf("forwarding should have succeeded") } if failure != nil { t.Fatalf("unexpected failure %T", failure) } } else { if linkError == nil { t.Fatalf("forwarding should have failed due to " + "inactive link") } if failure.Code() != testCase.expectedReply { t.Fatalf("unexpected failure %T", failure) } } if s.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } } // TestSkipIneligibleLinksLocalForward ensures that the switch will not attempt // to forward any HTLC's down a link that isn't yet eligible for forwarding. func TestSkipIneligibleLinksLocalForward(t *testing.T) { t.Parallel() testSkipLinkLocalForward(t, false, nil) } // TestSkipPolicyUnsatisfiedLinkLocalForward ensures that the switch will not // attempt to send locally initiated HTLCs that would violate the channel policy // down a link. func TestSkipPolicyUnsatisfiedLinkLocalForward(t *testing.T) { t.Parallel() testSkipLinkLocalForward(t, true, lnwire.NewTemporaryChannelFailure(nil)) } func testSkipLinkLocalForward(t *testing.T, eligible bool, policyResult lnwire.FailureMessage) { // We'll create a single link for this test, marking it as being unable // to forward form the get go. alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, _, aliceChanID, _ := genIDs() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, eligible, ) aliceChannelLink.checkHtlcTransitResult = NewLinkError( policyResult, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) addMsg := &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, } // We'll attempt to send out a new HTLC that has Alice as the first // outgoing link. This should fail as Alice isn't yet able to forward // any active HTLC's. err = s.SendHTLC(aliceChannelLink.ShortChanID(), 0, addMsg) if err == nil { t.Fatalf("local forward should fail due to inactive link") } if s.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } } // TestSwitchCancel checks that if htlc was rejected we remove unused // circuits. func TestSwitchCancel(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, chanID2, aliceChanID, bobChanID := genIDs() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarder from alice channel link // to bob channel link. preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) request := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, request); err != nil { t.Fatal(err) } select { case packet := <-bobChannelLink.packets: if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumPending() != 1 { t.Fatalf("wrong amount of half circuits") } if s.circuits.NumOpen() != 1 { t.Fatal("wrong amount of circuits") } // Create settle request pretending that bob channel link handled // the add htlc request and sent the htlc settle request back. This // request should be forwarder back to alice channel link. request = &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFailHTLC{}, } // Handle the request and checks that payment circuit works properly. if err := s.ForwardPackets(nil, request); err != nil { t.Fatal(err) } select { case pkt := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(pkt); err != nil { t.Fatalf("unable to remove circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to channelPoint") } if s.circuits.NumPending() != 0 { t.Fatal("wrong amount of circuits") } if s.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } } // TestSwitchAddSamePayment tests that we send the payment with the same // payment hash. func TestSwitchAddSamePayment(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarder from alice channel link // to bob channel link. preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) request := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, request); err != nil { t.Fatal(err) } select { case packet := <-bobChannelLink.packets: if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumOpen() != 1 { t.Fatal("wrong amount of circuits") } request = &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 1, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } // Handle the request and checks that bob channel link received it. if err := s.ForwardPackets(nil, request); err != nil { t.Fatal(err) } select { case packet := <-bobChannelLink.packets: if err := bobChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumOpen() != 2 { t.Fatal("wrong amount of circuits") } // Create settle request pretending that bob channel link handled // the add htlc request and sent the htlc settle request back. This // request should be forwarder back to alice channel link. request = &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFailHTLC{}, } // Handle the request and checks that payment circuit works properly. if err := s.ForwardPackets(nil, request); err != nil { t.Fatal(err) } select { case pkt := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(pkt); err != nil { t.Fatalf("unable to remove circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to channelPoint") } if s.circuits.NumOpen() != 1 { t.Fatal("wrong amount of circuits") } request = &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 1, amount: 1, htlc: &lnwire.UpdateFailHTLC{}, } // Handle the request and checks that payment circuit works properly. if err := s.ForwardPackets(nil, request); err != nil { t.Fatal(err) } select { case pkt := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(pkt); err != nil { t.Fatalf("unable to remove circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to channelPoint") } if s.circuits.NumOpen() != 0 { t.Fatal("wrong amount of circuits") } } // TestSwitchSendPayment tests ability of htlc switch to respond to the // users when response is came back from channel link. func TestSwitchSendPayment(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, _, aliceChanID, _ := genIDs() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add link: %v", err) } // Create request which should be forwarder from alice channel link // to bob channel link. preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) update := &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, } paymentID := uint64(123) // First check that the switch will correctly respond that this payment // ID is unknown. _, err = s.GetPaymentResult( paymentID, rhash, newMockDeobfuscator(), ) if err != ErrPaymentIDNotFound { t.Fatalf("expected ErrPaymentIDNotFound, got %v", err) } // Handle the request and checks that bob channel link received it. errChan := make(chan error) go func() { err := s.SendHTLC( aliceChannelLink.ShortChanID(), paymentID, update, ) if err != nil { errChan <- err return } resultChan, err := s.GetPaymentResult( paymentID, rhash, newMockDeobfuscator(), ) if err != nil { errChan <- err return } result, ok := <-resultChan if !ok { errChan <- fmt.Errorf("shutting down") } if result.Error != nil { errChan <- result.Error return } errChan <- nil }() select { case packet := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case err := <-errChan: if err != nil { t.Fatalf("unable to send payment: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } if s.circuits.NumOpen() != 1 { t.Fatal("wrong amount of circuits") } // Create fail request pretending that bob channel link handled // the add htlc request with error and sent the htlc fail request // back. This request should be forwarded back to alice channel link. obfuscator := NewMockObfuscator() failure := lnwire.NewFailIncorrectDetails(update.Amount, 100) reason, err := obfuscator.EncryptFirstHop(failure) if err != nil { t.Fatalf("unable obfuscate failure: %v", err) } if s.IsForwardedHTLC(aliceChannelLink.ShortChanID(), update.ID) { t.Fatal("htlc should be identified as not forwarded") } packet := &htlcPacket{ outgoingChanID: aliceChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFailHTLC{ Reason: reason, }, } if err := s.ForwardPackets(nil, packet); err != nil { t.Fatalf("can't forward htlc packet: %v", err) } select { case err := <-errChan: assertFailureCode( t, err, lnwire.CodeIncorrectOrUnknownPaymentDetails, ) case <-time.After(time.Second): t.Fatal("err wasn't received") } } // TestLocalPaymentNoForwardingEvents tests that if we send a series of locally // initiated payments, then they aren't reflected in the forwarding log. func TestLocalPaymentNoForwardingEvents(t *testing.T) { t.Parallel() // First, we'll create our traditional three hop network. We'll only be // interacting with and asserting the state of the first end point for // this test. channels, cleanUp, _, err := createClusterChannels( btcutil.SatoshiPerBitcoin*3, btcutil.SatoshiPerBitcoin*5) if err != nil { t.Fatalf("unable to create channel: %v", err) } defer cleanUp() n := newThreeHopNetwork(t, channels.aliceToBob, channels.bobToAlice, channels.bobToCarol, channels.carolToBob, testStartingHeight) if err := n.start(); err != nil { t.Fatalf("unable to start three hop network: %v", err) } // We'll now craft and send a payment from Alice to Bob. amount := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) htlcAmt, totalTimelock, hops := generateHops( amount, testStartingHeight, n.firstBobChannelLink, ) // With the payment crafted, we'll send it from Alice to Bob. We'll // wait for Alice to receive the preimage for the payment before // proceeding. receiver := n.bobServer firstHop := n.firstBobChannelLink.ShortChanID() _, err = makePayment( n.aliceServer, receiver, firstHop, hops, amount, htlcAmt, totalTimelock, ).Wait(30 * time.Second) if err != nil { t.Fatalf("unable to make the payment: %v", err) } // At this point, we'll forcibly stop the three hop network. Doing // this will cause any pending forwarding events to be flushed by the // various switches in the network. n.stop() // With all the switches stopped, we'll fetch Alice's mock forwarding // event log. log, ok := n.aliceServer.htlcSwitch.cfg.FwdingLog.(*mockForwardingLog) if !ok { t.Fatalf("mockForwardingLog assertion failed") } log.Lock() defer log.Unlock() // If we examine the memory of the forwarding log, then it should be // blank. if len(log.events) != 0 { t.Fatalf("log should have no events, instead has: %v", spew.Sdump(log.events)) } } // TestMultiHopPaymentForwardingEvents tests that if we send a series of // multi-hop payments via Alice->Bob->Carol. Then Bob properly logs forwarding // events, while Alice and Carol don't. func TestMultiHopPaymentForwardingEvents(t *testing.T) { t.Parallel() // First, we'll create our traditional three hop network. channels, cleanUp, _, err := createClusterChannels( btcutil.SatoshiPerBitcoin*3, btcutil.SatoshiPerBitcoin*5) if err != nil { t.Fatalf("unable to create channel: %v", err) } defer cleanUp() n := newThreeHopNetwork(t, channels.aliceToBob, channels.bobToAlice, channels.bobToCarol, channels.carolToBob, testStartingHeight) if err := n.start(); err != nil { t.Fatalf("unable to start three hop network: %v", err) } // We'll make now 10 payments, of 100k satoshis each from Alice to // Carol via Bob. const numPayments = 10 finalAmt := lnwire.NewMSatFromSatoshis(100000) htlcAmt, totalTimelock, hops := generateHops( finalAmt, testStartingHeight, n.firstBobChannelLink, n.carolChannelLink, ) firstHop := n.firstBobChannelLink.ShortChanID() for i := 0; i < numPayments/2; i++ { _, err := makePayment( n.aliceServer, n.carolServer, firstHop, hops, finalAmt, htlcAmt, totalTimelock, ).Wait(30 * time.Second) if err != nil { t.Fatalf("unable to send payment: %v", err) } } bobLog, ok := n.bobServer.htlcSwitch.cfg.FwdingLog.(*mockForwardingLog) if !ok { t.Fatalf("mockForwardingLog assertion failed") } // After sending 5 of the payments, trigger the forwarding ticker, to // make sure the events are properly flushed. bobTicker, ok := n.bobServer.htlcSwitch.cfg.FwdEventTicker.(*ticker.Force) if !ok { t.Fatalf("mockTicker assertion failed") } // We'll trigger the ticker, and wait for the events to appear in Bob's // forwarding log. timeout := time.After(15 * time.Second) for { select { case bobTicker.Force <- time.Now(): case <-time.After(1 * time.Second): t.Fatalf("unable to force tick") } // If all 5 events is found in Bob's log, we can break out and // continue the test. bobLog.Lock() if len(bobLog.events) == 5 { bobLog.Unlock() break } bobLog.Unlock() // Otherwise wait a little bit before checking again. select { case <-time.After(50 * time.Millisecond): case <-timeout: bobLog.Lock() defer bobLog.Unlock() t.Fatalf("expected 5 events in event log, instead "+ "found: %v", spew.Sdump(bobLog.events)) } } // Send the remaining payments. for i := numPayments / 2; i < numPayments; i++ { _, err := makePayment( n.aliceServer, n.carolServer, firstHop, hops, finalAmt, htlcAmt, totalTimelock, ).Wait(30 * time.Second) if err != nil { t.Fatalf("unable to send payment: %v", err) } } // With all 10 payments sent. We'll now manually stop each of the // switches so we can examine their end state. n.stop() // Alice and Carol shouldn't have any recorded forwarding events, as // they were the source and the sink for these payment flows. aliceLog, ok := n.aliceServer.htlcSwitch.cfg.FwdingLog.(*mockForwardingLog) if !ok { t.Fatalf("mockForwardingLog assertion failed") } aliceLog.Lock() defer aliceLog.Unlock() if len(aliceLog.events) != 0 { t.Fatalf("log should have no events, instead has: %v", spew.Sdump(aliceLog.events)) } carolLog, ok := n.carolServer.htlcSwitch.cfg.FwdingLog.(*mockForwardingLog) if !ok { t.Fatalf("mockForwardingLog assertion failed") } carolLog.Lock() defer carolLog.Unlock() if len(carolLog.events) != 0 { t.Fatalf("log should have no events, instead has: %v", spew.Sdump(carolLog.events)) } // Bob on the other hand, should have 10 events. bobLog.Lock() defer bobLog.Unlock() if len(bobLog.events) != 10 { t.Fatalf("log should have 10 events, instead has: %v", spew.Sdump(bobLog.events)) } // Each of the 10 events should have had all fields set properly. for _, event := range bobLog.events { // The incoming and outgoing channels should properly be set for // the event. if event.IncomingChanID != n.aliceChannelLink.ShortChanID() { t.Fatalf("chan id mismatch: expected %v, got %v", event.IncomingChanID, n.aliceChannelLink.ShortChanID()) } if event.OutgoingChanID != n.carolChannelLink.ShortChanID() { t.Fatalf("chan id mismatch: expected %v, got %v", event.OutgoingChanID, n.carolChannelLink.ShortChanID()) } // Additionally, the incoming and outgoing amounts should also // be properly set. if event.AmtIn != htlcAmt { t.Fatalf("incoming amt mismatch: expected %v, got %v", event.AmtIn, htlcAmt) } if event.AmtOut != finalAmt { t.Fatalf("outgoing amt mismatch: expected %v, got %v", event.AmtOut, finalAmt) } } } // TestUpdateFailMalformedHTLCErrorConversion tests that we're able to properly // convert malformed HTLC errors that originate at the direct link, as well as // during multi-hop HTLC forwarding. func TestUpdateFailMalformedHTLCErrorConversion(t *testing.T) { t.Parallel() // First, we'll create our traditional three hop network. channels, cleanUp, _, err := createClusterChannels( btcutil.SatoshiPerBitcoin*3, btcutil.SatoshiPerBitcoin*5, ) if err != nil { t.Fatalf("unable to create channel: %v", err) } defer cleanUp() n := newThreeHopNetwork( t, channels.aliceToBob, channels.bobToAlice, channels.bobToCarol, channels.carolToBob, testStartingHeight, ) if err := n.start(); err != nil { t.Fatalf("unable to start three hop network: %v", err) } assertPaymentFailure := func(t *testing.T) { // With the decoder modified, we'll now attempt to send a // payment from Alice to carol. finalAmt := lnwire.NewMSatFromSatoshis(100000) htlcAmt, totalTimelock, hops := generateHops( finalAmt, testStartingHeight, n.firstBobChannelLink, n.carolChannelLink, ) firstHop := n.firstBobChannelLink.ShortChanID() _, err = makePayment( n.aliceServer, n.carolServer, firstHop, hops, finalAmt, htlcAmt, totalTimelock, ).Wait(30 * time.Second) // The payment should fail as Carol is unable to decode the // onion blob sent to her. if err == nil { t.Fatalf("unable to send payment: %v", err) } routingErr := err.(ClearTextError) failureMsg := routingErr.WireMessage() if _, ok := failureMsg.(*lnwire.FailInvalidOnionKey); !ok { t.Fatalf("expected onion failure instead got: %v", routingErr.WireMessage()) } } t.Run("multi-hop error conversion", func(t *testing.T) { // Now that we have our network up, we'll modify the hop // iterator for the Bob <-> Carol channel to fail to decode in // order to simulate either a replay attack or an issue // decoding the onion. n.carolOnionDecoder.decodeFail = true assertPaymentFailure(t) }) t.Run("direct channel error conversion", func(t *testing.T) { // Similar to the above test case, we'll now make the Alice <-> // Bob link always fail to decode an onion. This differs from // the above test case in that there's no encryption on the // error at all since Alice will directly receive a // UpdateFailMalformedHTLC message. n.bobOnionDecoder.decodeFail = true assertPaymentFailure(t) }) } // TestSwitchGetPaymentResult tests that the switch interacts as expected with // the circuit map and network result store when looking up the result of a // payment ID. This is important for not to lose results under concurrent // lookup and receiving results. func TestSwitchGetPaymentResult(t *testing.T) { t.Parallel() const paymentID = 123 var preimg lntypes.Preimage preimg[0] = 3 s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() lookup := make(chan *PaymentCircuit, 1) s.circuits = &mockCircuitMap{ lookup: lookup, } // If the payment circuit is not found in the circuit map, the payment // result must be found in the store if available. Since we haven't // added anything to the store yet, ErrPaymentIDNotFound should be // returned. lookup <- nil _, err = s.GetPaymentResult( paymentID, lntypes.Hash{}, newMockDeobfuscator(), ) if err != ErrPaymentIDNotFound { t.Fatalf("expected ErrPaymentIDNotFound, got %v", err) } // Next let the lookup find the circuit in the circuit map. It should // subscribe to payment results, and return the result when available. lookup <- &PaymentCircuit{} resultChan, err := s.GetPaymentResult( paymentID, lntypes.Hash{}, newMockDeobfuscator(), ) if err != nil { t.Fatalf("unable to get payment result: %v", err) } // Add the result to the store. n := &networkResult{ msg: &lnwire.UpdateFulfillHTLC{ PaymentPreimage: preimg, }, unencrypted: true, isResolution: true, } err = s.networkResults.storeResult(paymentID, n) if err != nil { t.Fatalf("unable to store result: %v", err) } // The result should be availble. select { case res, ok := <-resultChan: if !ok { t.Fatalf("channel was closed") } if res.Error != nil { t.Fatalf("got unexpected error result") } if res.Preimage != preimg { t.Fatalf("expected preimg %v, got %v", preimg, res.Preimage) } case <-time.After(1 * time.Second): t.Fatalf("result not received") } // As a final test, try to get the result again. Now that is no longer // in the circuit map, it should be immediately available from the // store. lookup <- nil resultChan, err = s.GetPaymentResult( paymentID, lntypes.Hash{}, newMockDeobfuscator(), ) if err != nil { t.Fatalf("unable to get payment result: %v", err) } select { case res, ok := <-resultChan: if !ok { t.Fatalf("channel was closed") } if res.Error != nil { t.Fatalf("got unexpected error result") } if res.Preimage != preimg { t.Fatalf("expected preimg %v, got %v", preimg, res.Preimage) } case <-time.After(1 * time.Second): t.Fatalf("result not received") } } // TestInvalidFailure tests that the switch returns an unreadable failure error // if the failure cannot be decrypted. func TestInvalidFailure(t *testing.T) { t.Parallel() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } s, err := initSwitchWithDB(testStartingHeight, nil) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer s.Stop() chanID1, _, aliceChanID, _ := genIDs() // Set up a mock channel link. aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add link: %v", err) } // Create a request which should be forwarded to the mock channel link. preimage, err := genPreimage() if err != nil { t.Fatalf("unable to generate preimage: %v", err) } rhash := sha256.Sum256(preimage[:]) update := &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, } paymentID := uint64(123) // Send the request. err = s.SendHTLC( aliceChannelLink.ShortChanID(), paymentID, update, ) if err != nil { t.Fatalf("unable to send payment: %v", err) } // Catch the packet and complete the circuit so that the switch is ready // for a response. select { case packet := <-aliceChannelLink.packets: if err := aliceChannelLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): t.Fatal("request was not propagated to destination") } // Send response packet with an unreadable failure message to the // switch. The reason failed is not relevant, because we mock the // decryption. packet := &htlcPacket{ outgoingChanID: aliceChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFailHTLC{ Reason: []byte{1, 2, 3}, }, } if err := s.ForwardPackets(nil, packet); err != nil { t.Fatalf("can't forward htlc packet: %v", err) } // Get payment result from switch. We expect an unreadable failure // message error. deobfuscator := SphinxErrorDecrypter{ OnionErrorDecrypter: &mockOnionErrorDecryptor{ err: ErrUnreadableFailureMessage, }, } resultChan, err := s.GetPaymentResult( paymentID, rhash, &deobfuscator, ) if err != nil { t.Fatal(err) } select { case result := <-resultChan: if result.Error != ErrUnreadableFailureMessage { t.Fatal("expected unreadable failure message") } case <-time.After(time.Second): t.Fatal("err wasn't received") } // Modify the decryption to simulate that decryption went alright, but // the failure cannot be decoded. deobfuscator = SphinxErrorDecrypter{ OnionErrorDecrypter: &mockOnionErrorDecryptor{ sourceIdx: 2, message: []byte{200}, }, } resultChan, err = s.GetPaymentResult( paymentID, rhash, &deobfuscator, ) if err != nil { t.Fatal(err) } select { case result := <-resultChan: rtErr, ok := result.Error.(ClearTextError) if !ok { t.Fatal("expected ClearTextError") } source, ok := rtErr.(*ForwardingError) if !ok { t.Fatalf("expected forwarding error, got: %T", rtErr) } if source.FailureSourceIdx != 2 { t.Fatal("unexpected error source index") } if rtErr.WireMessage() != nil { t.Fatal("expected empty failure message") } case <-time.After(time.Second): t.Fatal("err wasn't received") } } // htlcNotifierEvents is a function that generates a set of expected htlc // notifier evetns for each node in a three hop network with the dynamic // values provided. These functions take dynamic values so that changes to // external systems (such as our default timelock delta) do not break // these tests. type htlcNotifierEvents func(channels *clusterChannels, htlcID uint64, ts time.Time, htlc *lnwire.UpdateAddHTLC, hops []*hop.Payload) ([]interface{}, []interface{}, []interface{}) // TestHtlcNotifier tests the notifying of htlc events that are routed over a // three hop network. It sets up an Alice -> Bob -> Carol network and routes // payments from Alice -> Carol to test events from the perspective of a // sending (Alice), forwarding (Bob) and receiving (Carol) node. Test cases // are present for saduccessful and failed payments. func TestHtlcNotifier(t *testing.T) { tests := []struct { name string // Options is a set of options to apply to the three hop // network's servers. options []serverOption // expectedEvents is a function which returns an expected set // of events for the test. expectedEvents htlcNotifierEvents // iterations is the number of times we will send a payment, // this is used to send more than one payment to force non- // zero htlc indexes to make sure we aren't just checking // default values. iterations int }{ { name: "successful three hop payment", options: nil, expectedEvents: func(channels *clusterChannels, htlcID uint64, ts time.Time, htlc *lnwire.UpdateAddHTLC, hops []*hop.Payload) ([]interface{}, []interface{}, []interface{}) { return getThreeHopEvents( channels, htlcID, ts, htlc, hops, nil, ) }, iterations: 2, }, { name: "failed at forwarding link", // Set a functional option which disables bob as a // forwarding node to force a payment error. options: []serverOption{ serverOptionRejectHtlc(false, true, false), }, expectedEvents: func(channels *clusterChannels, htlcID uint64, ts time.Time, htlc *lnwire.UpdateAddHTLC, hops []*hop.Payload) ([]interface{}, []interface{}, []interface{}) { return getThreeHopEvents( channels, htlcID, ts, htlc, hops, &LinkError{ msg: &lnwire.FailChannelDisabled{}, FailureDetail: OutgoingFailureForwardsDisabled, }, ) }, iterations: 1, }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { testHtcNotifier( t, test.options, test.iterations, test.expectedEvents, ) }) } } // testHtcNotifier runs a htlc notifier test. func testHtcNotifier(t *testing.T, testOpts []serverOption, iterations int, getEvents htlcNotifierEvents) { t.Parallel() // First, we'll create our traditional three hop // network. channels, cleanUp, _, err := createClusterChannels( btcutil.SatoshiPerBitcoin*3, btcutil.SatoshiPerBitcoin*5) if err != nil { t.Fatalf("unable to create channel: %v", err) } defer cleanUp() // Mock time so that all events are reported with a static timestamp. now := time.Now() mockTime := func() time.Time { return now } // Create htlc notifiers for each server in the three hop network and // start them. aliceNotifier := NewHtlcNotifier(mockTime) if err := aliceNotifier.Start(); err != nil { t.Fatalf("could not start alice notifier") } defer aliceNotifier.Stop() bobNotifier := NewHtlcNotifier(mockTime) if err := bobNotifier.Start(); err != nil { t.Fatalf("could not start bob notifier") } defer bobNotifier.Stop() carolNotifier := NewHtlcNotifier(mockTime) if err := carolNotifier.Start(); err != nil { t.Fatalf("could not start carol notifier") } defer carolNotifier.Stop() // Create a notifier server option which will set our htlc notifiers // for the three hop network. notifierOption := serverOptionWithHtlcNotifier( aliceNotifier, bobNotifier, carolNotifier, ) // Add the htlcNotifier option to any other options // set in the test. options := append(testOpts, notifierOption) n := newThreeHopNetwork( t, channels.aliceToBob, channels.bobToAlice, channels.bobToCarol, channels.carolToBob, testStartingHeight, options..., ) if err := n.start(); err != nil { t.Fatalf("unable to start three hop "+ "network: %v", err) } defer n.stop() // Before we forward anything, subscribe to htlc events // from each notifier. aliceEvents, err := aliceNotifier.SubscribeHtlcEvents() if err != nil { t.Fatalf("could not subscribe to alice's"+ " events: %v", err) } defer aliceEvents.Cancel() bobEvents, err := bobNotifier.SubscribeHtlcEvents() if err != nil { t.Fatalf("could not subscribe to bob's"+ " events: %v", err) } defer bobEvents.Cancel() carolEvents, err := carolNotifier.SubscribeHtlcEvents() if err != nil { t.Fatalf("could not subscribe to carol's"+ " events: %v", err) } defer carolEvents.Cancel() // Send multiple payments, as specified by the test to test incrementing // of htlc ids. for i := 0; i < iterations; i++ { // We'll start off by making a payment from // Alice -> Bob -> Carol. htlc, hops := n.sendThreeHopPayment(t) alice, bob, carol := getEvents( channels, uint64(i), now, htlc, hops, ) checkHtlcEvents(t, aliceEvents.Updates(), alice) checkHtlcEvents(t, bobEvents.Updates(), bob) checkHtlcEvents(t, carolEvents.Updates(), carol) } } // checkHtlcEvents checks that a subscription has the set of htlc events // we expect it to have. func checkHtlcEvents(t *testing.T, events <-chan interface{}, expectedEvents []interface{}) { t.Helper() for _, expected := range expectedEvents { select { case event := <-events: if !reflect.DeepEqual(event, expected) { t.Fatalf("expected %v, got: %v", expected, event) } case <-time.After(5 * time.Second): t.Fatalf("expected event: %v", expected) } } } // sendThreeHopPayment is a helper function which sends a payment over // Alice -> Bob -> Carol in a three hop network and returns Alice's first htlc // and the remainder of the hops. func (n *threeHopNetwork) sendThreeHopPayment(t *testing.T) (*lnwire.UpdateAddHTLC, []*hop.Payload) { amount := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) htlcAmt, totalTimelock, hops := generateHops(amount, testStartingHeight, n.firstBobChannelLink, n.carolChannelLink) blob, err := generateRoute(hops...) if err != nil { t.Fatal(err) } invoice, htlc, pid, err := generatePayment( amount, htlcAmt, totalTimelock, blob, ) if err != nil { t.Fatal(err) } err = n.carolServer.registry.AddInvoice(*invoice, htlc.PaymentHash) if err != nil { t.Fatalf("unable to add invoice in carol registry: %v", err) } if err := n.aliceServer.htlcSwitch.SendHTLC( n.firstBobChannelLink.ShortChanID(), pid, htlc, ); err != nil { t.Fatalf("could not send htlc") } return htlc, hops } // getThreeHopEvents gets the set of htlc events that we expect for a payment // from Alice -> Bob -> Carol. If a non-nil link error is provided, the set // of events will fail on Bob's outgoing link. func getThreeHopEvents(channels *clusterChannels, htlcID uint64, ts time.Time, htlc *lnwire.UpdateAddHTLC, hops []*hop.Payload, linkError *LinkError) ([]interface{}, []interface{}, []interface{}) { aliceKey := HtlcKey{ IncomingCircuit: zeroCircuit, OutgoingCircuit: channeldb.CircuitKey{ ChanID: channels.aliceToBob.ShortChanID(), HtlcID: htlcID, }, } // Alice always needs a forwarding event because she initiates the // send. aliceEvents := []interface{}{ &ForwardingEvent{ HtlcKey: aliceKey, HtlcInfo: HtlcInfo{ OutgoingTimeLock: htlc.Expiry, OutgoingAmt: htlc.Amount, }, HtlcEventType: HtlcEventTypeSend, Timestamp: ts, }, } bobKey := HtlcKey{ IncomingCircuit: channeldb.CircuitKey{ ChanID: channels.bobToAlice.ShortChanID(), HtlcID: htlcID, }, OutgoingCircuit: channeldb.CircuitKey{ ChanID: channels.bobToCarol.ShortChanID(), HtlcID: htlcID, }, } bobInfo := HtlcInfo{ IncomingTimeLock: htlc.Expiry, IncomingAmt: htlc.Amount, OutgoingTimeLock: hops[1].FwdInfo.OutgoingCTLV, OutgoingAmt: hops[1].FwdInfo.AmountToForward, } // If we expect the payment to fail, we add failures for alice and // bob, and no events for carol because the payment never reaches her. if linkError != nil { aliceEvents = append(aliceEvents, &ForwardingFailEvent{ HtlcKey: aliceKey, HtlcEventType: HtlcEventTypeSend, Timestamp: ts, }, ) bobEvents := []interface{}{ &LinkFailEvent{ HtlcKey: bobKey, HtlcInfo: bobInfo, HtlcEventType: HtlcEventTypeForward, LinkError: linkError, Incoming: false, Timestamp: ts, }, } return aliceEvents, bobEvents, nil } // If we want to get events for a successful payment, we add a settle // for alice, a forward and settle for bob and a receive settle for // carol. aliceEvents = append( aliceEvents, &SettleEvent{ HtlcKey: aliceKey, HtlcEventType: HtlcEventTypeSend, Timestamp: ts, }, ) bobEvents := []interface{}{ &ForwardingEvent{ HtlcKey: bobKey, HtlcInfo: bobInfo, HtlcEventType: HtlcEventTypeForward, Timestamp: ts, }, &SettleEvent{ HtlcKey: bobKey, HtlcEventType: HtlcEventTypeForward, Timestamp: ts, }, } carolEvents := []interface{}{ &SettleEvent{ HtlcKey: HtlcKey{ IncomingCircuit: channeldb.CircuitKey{ ChanID: channels.carolToBob.ShortChanID(), HtlcID: htlcID, }, OutgoingCircuit: zeroCircuit, }, HtlcEventType: HtlcEventTypeReceive, Timestamp: ts, }, } return aliceEvents, bobEvents, carolEvents } type mockForwardInterceptor struct { intercepted InterceptedForward } func (m *mockForwardInterceptor) InterceptForwardHtlc(intercepted InterceptedForward) bool { m.intercepted = intercepted return true } func (m *mockForwardInterceptor) settle(preimage lntypes.Preimage) error { return m.intercepted.Settle(preimage) } func (m *mockForwardInterceptor) fail() error { return m.intercepted.Fail() } func (m *mockForwardInterceptor) resume() error { return m.intercepted.Resume() } func assertNumCircuits(t *testing.T, s *Switch, pending, opened int) { if s.circuits.NumPending() != pending { t.Fatal("wrong amount of half circuits") } if s.circuits.NumOpen() != opened { t.Fatal("wrong amount of circuits") } } func assertOutgoingLinkReceive(t *testing.T, targetLink *mockChannelLink, expectReceive bool) { // Pull packet from targetLink link. select { case packet := <-targetLink.packets: if !expectReceive { t.Fatal("forward was intercepted, shouldn't land at bob link") } else if err := targetLink.completeCircuit(packet); err != nil { t.Fatalf("unable to complete payment circuit: %v", err) } case <-time.After(time.Second): if expectReceive { t.Fatal("request was not propagated to destination") } } } func TestSwitchHoldForward(t *testing.T) { t.Parallel() chanID1, chanID2, aliceChanID, bobChanID := genIDs() alicePeer, err := newMockServer( t, "alice", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create alice server: %v", err) } bobPeer, err := newMockServer( t, "bob", testStartingHeight, nil, testDefaultDelta, ) if err != nil { t.Fatalf("unable to create bob server: %v", err) } tempPath, err := ioutil.TempDir("", "circuitdb") if err != nil { t.Fatalf("unable to temporary path: %v", err) } cdb, err := channeldb.Open(tempPath) if err != nil { t.Fatalf("unable to open channeldb: %v", err) } s, err := initSwitchWithDB(testStartingHeight, cdb) if err != nil { t.Fatalf("unable to init switch: %v", err) } if err := s.Start(); err != nil { t.Fatalf("unable to start switch: %v", err) } defer func() { if err := s.Stop(); err != nil { t.Fatalf(err.Error()) } }() aliceChannelLink := newMockChannelLink( s, chanID1, aliceChanID, alicePeer, true, ) bobChannelLink := newMockChannelLink( s, chanID2, bobChanID, bobPeer, true, ) if err := s.AddLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice link: %v", err) } if err := s.AddLink(bobChannelLink); err != nil { t.Fatalf("unable to add bob link: %v", err) } // Create request which should be forwarded from Alice channel link to // bob channel link. preimage := [sha256.Size]byte{1} rhash := sha256.Sum256(preimage[:]) ogPacket := &htlcPacket{ incomingChanID: aliceChannelLink.ShortChanID(), incomingHTLCID: 0, outgoingChanID: bobChannelLink.ShortChanID(), obfuscator: NewMockObfuscator(), htlc: &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: 1, }, } forwardInterceptor := &mockForwardInterceptor{} switchForwardInterceptor := NewInterceptableSwitch(s) switchForwardInterceptor.SetInterceptor(forwardInterceptor.InterceptForwardHtlc) linkQuit := make(chan struct{}) // Test resume a hold forward assertNumCircuits(t, s, 0, 0) if err := switchForwardInterceptor.ForwardPackets(linkQuit, ogPacket); err != nil { t.Fatalf("can't forward htlc packet: %v", err) } assertNumCircuits(t, s, 0, 0) assertOutgoingLinkReceive(t, bobChannelLink, false) if err := forwardInterceptor.resume(); err != nil { t.Fatalf("failed to resume forward") } assertOutgoingLinkReceive(t, bobChannelLink, true) assertNumCircuits(t, s, 1, 1) // settling the htlc to close the circuit. settle := &htlcPacket{ outgoingChanID: bobChannelLink.ShortChanID(), outgoingHTLCID: 0, amount: 1, htlc: &lnwire.UpdateFulfillHTLC{ PaymentPreimage: preimage, }, } if err := switchForwardInterceptor.ForwardPackets(linkQuit, settle); err != nil { t.Fatalf("can't forward htlc packet: %v", err) } assertOutgoingLinkReceive(t, aliceChannelLink, true) assertNumCircuits(t, s, 0, 0) // Test failing a hold forward if err := switchForwardInterceptor.ForwardPackets(linkQuit, ogPacket); err != nil { t.Fatalf("can't forward htlc packet: %v", err) } assertNumCircuits(t, s, 0, 0) assertOutgoingLinkReceive(t, bobChannelLink, false) if err := forwardInterceptor.fail(); err != nil { t.Fatalf("failed to cancel forward %v", err) } assertOutgoingLinkReceive(t, bobChannelLink, false) assertOutgoingLinkReceive(t, aliceChannelLink, true) assertNumCircuits(t, s, 0, 0) // Test settling a hold forward if err := switchForwardInterceptor.ForwardPackets(linkQuit, ogPacket); err != nil { t.Fatalf("can't forward htlc packet: %v", err) } assertNumCircuits(t, s, 0, 0) assertOutgoingLinkReceive(t, bobChannelLink, false) if err := forwardInterceptor.settle(preimage); err != nil { t.Fatal("failed to cancel forward") } assertOutgoingLinkReceive(t, bobChannelLink, false) assertOutgoingLinkReceive(t, aliceChannelLink, true) assertNumCircuits(t, s, 0, 0) }