package discovery import ( "fmt" "math" "reflect" "sync/atomic" "testing" "time" "github.com/davecgh/go-spew/spew" "github.com/lightningnetwork/lnd/lntest/wait" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/ticker" ) // randPeer creates a random peer. func randPeer(t *testing.T, quit chan struct{}) *mockPeer { t.Helper() return &mockPeer{ pk: randPubKey(t), sentMsgs: make(chan lnwire.Message), quit: quit, } } // newTestSyncManager creates a new test SyncManager using mock implementations // of its dependencies. func newTestSyncManager(numActiveSyncers int) *SyncManager { hID := lnwire.ShortChannelID{BlockHeight: latestKnownHeight} return newSyncManager(&SyncManagerCfg{ ChanSeries: newMockChannelGraphTimeSeries(hID), RotateTicker: ticker.NewForce(DefaultSyncerRotationInterval), HistoricalSyncTicker: ticker.NewForce(DefaultHistoricalSyncInterval), NumActiveSyncers: numActiveSyncers, }) } // TestSyncManagerNumActiveSyncers ensures that we are unable to have more than // NumActiveSyncers active syncers. func TestSyncManagerNumActiveSyncers(t *testing.T) { t.Parallel() // We'll start by creating our test sync manager which will hold up to // 3 active syncers. const numActiveSyncers = 3 const numSyncers = numActiveSyncers + 1 syncMgr := newTestSyncManager(numActiveSyncers) syncMgr.Start() defer syncMgr.Stop() // We'll go ahead and create our syncers. We'll gather the ones which // should be active and passive to check them later on. for i := 0; i < numActiveSyncers; i++ { peer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(peer) s := assertSyncerExistence(t, syncMgr, peer) // The first syncer registered always attempts a historical // sync. if i == 0 { assertTransitionToChansSynced(t, s, peer) } assertActiveGossipTimestampRange(t, peer) assertSyncerStatus(t, s, chansSynced, ActiveSync) } for i := 0; i < numSyncers-numActiveSyncers; i++ { peer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(peer) s := assertSyncerExistence(t, syncMgr, peer) assertSyncerStatus(t, s, chansSynced, PassiveSync) } } // TestSyncManagerNewActiveSyncerAfterDisconnect ensures that we can regain an // active syncer after losing one due to the peer disconnecting. func TestSyncManagerNewActiveSyncerAfterDisconnect(t *testing.T) { t.Parallel() // We'll create our test sync manager to have two active syncers. syncMgr := newTestSyncManager(2) syncMgr.Start() defer syncMgr.Stop() // The first will be an active syncer that performs a historical sync // since it is the first one registered with the SyncManager. historicalSyncPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(historicalSyncPeer) historicalSyncer := assertSyncerExistence(t, syncMgr, historicalSyncPeer) assertTransitionToChansSynced(t, historicalSyncer, historicalSyncPeer) assertActiveGossipTimestampRange(t, historicalSyncPeer) assertSyncerStatus(t, historicalSyncer, chansSynced, ActiveSync) // Then, we'll create the second active syncer, which is the one we'll // disconnect. activeSyncPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(activeSyncPeer) activeSyncer := assertSyncerExistence(t, syncMgr, activeSyncPeer) assertActiveGossipTimestampRange(t, activeSyncPeer) assertSyncerStatus(t, activeSyncer, chansSynced, ActiveSync) // It will then be torn down to simulate a disconnection. Since there // are no other candidate syncers available, the active syncer won't be // replaced. syncMgr.PruneSyncState(activeSyncPeer.PubKey()) // Then, we'll start our active syncer again, but this time we'll also // have a passive syncer available to replace the active syncer after // the peer disconnects. syncMgr.InitSyncState(activeSyncPeer) activeSyncer = assertSyncerExistence(t, syncMgr, activeSyncPeer) assertActiveGossipTimestampRange(t, activeSyncPeer) assertSyncerStatus(t, activeSyncer, chansSynced, ActiveSync) // Create our second peer, which should be initialized as a passive // syncer. newActiveSyncPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(newActiveSyncPeer) newActiveSyncer := assertSyncerExistence(t, syncMgr, newActiveSyncPeer) assertSyncerStatus(t, newActiveSyncer, chansSynced, PassiveSync) // Disconnect our active syncer, which should trigger the SyncManager to // replace it with our passive syncer. go syncMgr.PruneSyncState(activeSyncPeer.PubKey()) assertPassiveSyncerTransition(t, newActiveSyncer, newActiveSyncPeer) } // TestSyncManagerRotateActiveSyncerCandidate tests that we can successfully // rotate our active syncers after a certain interval. func TestSyncManagerRotateActiveSyncerCandidate(t *testing.T) { t.Parallel() // We'll create our sync manager with three active syncers. syncMgr := newTestSyncManager(1) syncMgr.Start() defer syncMgr.Stop() // The first syncer registered always performs a historical sync. activeSyncPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(activeSyncPeer) activeSyncer := assertSyncerExistence(t, syncMgr, activeSyncPeer) assertTransitionToChansSynced(t, activeSyncer, activeSyncPeer) assertActiveGossipTimestampRange(t, activeSyncPeer) assertSyncerStatus(t, activeSyncer, chansSynced, ActiveSync) // We'll send a tick to force a rotation. Since there aren't any // candidates, none of the active syncers will be rotated. syncMgr.cfg.RotateTicker.(*ticker.Force).Force <- time.Time{} assertNoMsgSent(t, activeSyncPeer) assertSyncerStatus(t, activeSyncer, chansSynced, ActiveSync) // We'll then go ahead and add a passive syncer. passiveSyncPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(passiveSyncPeer) passiveSyncer := assertSyncerExistence(t, syncMgr, passiveSyncPeer) assertSyncerStatus(t, passiveSyncer, chansSynced, PassiveSync) // We'll force another rotation - this time, since we have a passive // syncer available, they should be rotated. syncMgr.cfg.RotateTicker.(*ticker.Force).Force <- time.Time{} // The transition from an active syncer to a passive syncer causes the // peer to send out a new GossipTimestampRange in the past so that they // don't receive new graph updates. assertActiveSyncerTransition(t, activeSyncer, activeSyncPeer) // The transition from a passive syncer to an active syncer causes the // peer to send a new GossipTimestampRange with the current timestamp to // signal that they would like to receive new graph updates from their // peers. This will also cause the gossip syncer to redo its state // machine, starting from its initial syncingChans state. We'll then // need to transition it to its final chansSynced state to ensure the // next syncer is properly started in the round-robin. assertPassiveSyncerTransition(t, passiveSyncer, passiveSyncPeer) } // TestSyncManagerInitialHistoricalSync ensures that we only attempt a single // historical sync during the SyncManager's startup. If the peer corresponding // to the initial historical syncer disconnects, we should attempt to find a // replacement. func TestSyncManagerInitialHistoricalSync(t *testing.T) { t.Parallel() syncMgr := newTestSyncManager(0) // The graph should not be considered as synced since the sync manager // has yet to start. if syncMgr.IsGraphSynced() { t.Fatal("expected graph to not be considered as synced") } syncMgr.Start() defer syncMgr.Stop() // We should expect to see a QueryChannelRange message with a // FirstBlockHeight of the genesis block, signaling that an initial // historical sync is being attempted. peer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(peer) assertMsgSent(t, peer, &lnwire.QueryChannelRange{ FirstBlockHeight: 0, NumBlocks: math.MaxUint32, }) // The graph should not be considered as synced since the initial // historical sync has not finished. if syncMgr.IsGraphSynced() { t.Fatal("expected graph to not be considered as synced") } // If an additional peer connects, then another historical sync should // not be attempted. finalHistoricalPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(finalHistoricalPeer) finalHistoricalSyncer := assertSyncerExistence(t, syncMgr, finalHistoricalPeer) assertNoMsgSent(t, finalHistoricalPeer) // If we disconnect the peer performing the initial historical sync, a // new one should be chosen. syncMgr.PruneSyncState(peer.PubKey()) // Complete the initial historical sync by transitionining the syncer to // its final chansSynced state. The graph should be considered as synced // after the fact. assertTransitionToChansSynced(t, finalHistoricalSyncer, finalHistoricalPeer) if !syncMgr.IsGraphSynced() { t.Fatal("expected graph to be considered as synced") } // Once the initial historical sync has succeeded, another one should // not be attempted by disconnecting the peer who performed it. extraPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(extraPeer) assertNoMsgSent(t, extraPeer) syncMgr.PruneSyncState(finalHistoricalPeer.PubKey()) assertNoMsgSent(t, extraPeer) } // TestSyncManagerHistoricalSyncOnReconnect tests that the sync manager will // re-trigger a historical sync when a new peer connects after a historical // sync has completed, but we have lost all peers. func TestSyncManagerHistoricalSyncOnReconnect(t *testing.T) { t.Parallel() syncMgr := newTestSyncManager(2) syncMgr.Start() defer syncMgr.Stop() // We should expect to see a QueryChannelRange message with a // FirstBlockHeight of the genesis block, signaling that an initial // historical sync is being attempted. peer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(peer) s := assertSyncerExistence(t, syncMgr, peer) assertTransitionToChansSynced(t, s, peer) assertActiveGossipTimestampRange(t, peer) assertSyncerStatus(t, s, chansSynced, ActiveSync) // Now that the historical sync is completed, we prune the syncer, // simulating all peers having disconnected. syncMgr.PruneSyncState(peer.PubKey()) // If a new peer now connects, then another historical sync should // be attempted. This is to ensure we get an up-to-date graph if we // haven't had any peers for a time. nextPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(nextPeer) s1 := assertSyncerExistence(t, syncMgr, nextPeer) assertTransitionToChansSynced(t, s1, nextPeer) assertActiveGossipTimestampRange(t, nextPeer) assertSyncerStatus(t, s1, chansSynced, ActiveSync) } // TestSyncManagerForceHistoricalSync ensures that we can perform routine // historical syncs whenever the HistoricalSyncTicker fires. func TestSyncManagerForceHistoricalSync(t *testing.T) { t.Parallel() syncMgr := newTestSyncManager(0) syncMgr.Start() defer syncMgr.Stop() // We should expect to see a QueryChannelRange message with a // FirstBlockHeight of the genesis block, signaling that a historical // sync is being attempted. peer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(peer) assertMsgSent(t, peer, &lnwire.QueryChannelRange{ FirstBlockHeight: 0, NumBlocks: math.MaxUint32, }) // If an additional peer connects, then a historical sync should not be // attempted again. extraPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(extraPeer) assertNoMsgSent(t, extraPeer) // Then, we'll send a tick to force a historical sync. This should // trigger the extra peer to also perform a historical sync since the // first peer is not eligible due to not being in a chansSynced state. syncMgr.cfg.HistoricalSyncTicker.(*ticker.Force).Force <- time.Time{} assertMsgSent(t, extraPeer, &lnwire.QueryChannelRange{ FirstBlockHeight: 0, NumBlocks: math.MaxUint32, }) } // TestSyncManagerGraphSyncedAfterHistoricalSyncReplacement ensures that the // sync manager properly marks the graph as synced given that our initial // historical sync has stalled, but a replacement has fully completed. func TestSyncManagerGraphSyncedAfterHistoricalSyncReplacement(t *testing.T) { t.Parallel() syncMgr := newTestSyncManager(0) syncMgr.Start() defer syncMgr.Stop() // We should expect to see a QueryChannelRange message with a // FirstBlockHeight of the genesis block, signaling that an initial // historical sync is being attempted. peer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(peer) assertMsgSent(t, peer, &lnwire.QueryChannelRange{ FirstBlockHeight: 0, NumBlocks: math.MaxUint32, }) // The graph should not be considered as synced since the initial // historical sync has not finished. if syncMgr.IsGraphSynced() { t.Fatal("expected graph to not be considered as synced") } // If an additional peer connects, then another historical sync should // not be attempted. finalHistoricalPeer := randPeer(t, syncMgr.quit) syncMgr.InitSyncState(finalHistoricalPeer) finalHistoricalSyncer := assertSyncerExistence(t, syncMgr, finalHistoricalPeer) assertNoMsgSent(t, finalHistoricalPeer) // To simulate that our initial historical sync has stalled, we'll force // a historical sync with the new peer to ensure it is replaced. syncMgr.cfg.HistoricalSyncTicker.(*ticker.Force).Force <- time.Time{} // The graph should still not be considered as synced since the // replacement historical sync has not finished. if syncMgr.IsGraphSynced() { t.Fatal("expected graph to not be considered as synced") } // Complete the replacement historical sync by transitioning the syncer // to its final chansSynced state. The graph should be considered as // synced after the fact. assertTransitionToChansSynced(t, finalHistoricalSyncer, finalHistoricalPeer) if !syncMgr.IsGraphSynced() { t.Fatal("expected graph to be considered as synced") } } // TestSyncManagerWaitUntilInitialHistoricalSync ensures that no GossipSyncers // are initialized as ActiveSync until the initial historical sync has been // completed. Once it does, the pending GossipSyncers should be transitioned to // ActiveSync. func TestSyncManagerWaitUntilInitialHistoricalSync(t *testing.T) { t.Parallel() const numActiveSyncers = 2 // We'll start by creating our test sync manager which will hold up to // 2 active syncers. syncMgr := newTestSyncManager(numActiveSyncers) syncMgr.Start() defer syncMgr.Stop() // We'll go ahead and create our syncers. peers := make([]*mockPeer, 0, numActiveSyncers) syncers := make([]*GossipSyncer, 0, numActiveSyncers) for i := 0; i < numActiveSyncers; i++ { peer := randPeer(t, syncMgr.quit) peers = append(peers, peer) syncMgr.InitSyncState(peer) s := assertSyncerExistence(t, syncMgr, peer) syncers = append(syncers, s) // The first one always attempts a historical sync. We won't // transition it to chansSynced to ensure the remaining syncers // aren't started as active. if i == 0 { assertSyncerStatus(t, s, syncingChans, PassiveSync) continue } // The rest should remain in a passive and chansSynced state, // and they should be queued to transition to active once the // initial historical sync is completed. assertNoMsgSent(t, peer) assertSyncerStatus(t, s, chansSynced, PassiveSync) } // To ensure we don't transition any pending active syncers that have // previously disconnected, we'll disconnect the last one. stalePeer := peers[numActiveSyncers-1] syncMgr.PruneSyncState(stalePeer.PubKey()) // Then, we'll complete the initial historical sync by transitioning the // historical syncer to its final chansSynced state. This should trigger // all of the pending active syncers to transition, except for the one // we disconnected. assertTransitionToChansSynced(t, syncers[0], peers[0]) for i, s := range syncers { if i == numActiveSyncers-1 { assertNoMsgSent(t, peers[i]) continue } assertPassiveSyncerTransition(t, s, peers[i]) } } // assertNoMsgSent is a helper function that ensures a peer hasn't sent any // messages. func assertNoMsgSent(t *testing.T, peer *mockPeer) { t.Helper() select { case msg := <-peer.sentMsgs: t.Fatalf("peer %x sent unexpected message %v", peer.PubKey(), spew.Sdump(msg)) case <-time.After(time.Second): } } // assertMsgSent asserts that the peer has sent the given message. func assertMsgSent(t *testing.T, peer *mockPeer, msg lnwire.Message) { t.Helper() var msgSent lnwire.Message select { case msgSent = <-peer.sentMsgs: case <-time.After(time.Second): t.Fatalf("expected peer %x to send %T message", peer.PubKey(), msg) } if !reflect.DeepEqual(msgSent, msg) { t.Fatalf("expected peer %x to send message: %v\ngot: %v", peer.PubKey(), spew.Sdump(msg), spew.Sdump(msgSent)) } } // assertActiveGossipTimestampRange is a helper function that ensures a peer has // sent a lnwire.GossipTimestampRange message indicating that it would like to // receive new graph updates. func assertActiveGossipTimestampRange(t *testing.T, peer *mockPeer) { t.Helper() var msgSent lnwire.Message select { case msgSent = <-peer.sentMsgs: case <-time.After(2 * time.Second): t.Fatalf("expected peer %x to send lnwire.GossipTimestampRange "+ "message", peer.PubKey()) } msg, ok := msgSent.(*lnwire.GossipTimestampRange) if !ok { t.Fatalf("expected peer %x to send %T message", peer.PubKey(), msg) } if msg.FirstTimestamp == 0 { t.Fatalf("expected *lnwire.GossipTimestampRange message with " + "non-zero FirstTimestamp") } if msg.TimestampRange == 0 { t.Fatalf("expected *lnwire.GossipTimestampRange message with " + "non-zero TimestampRange") } } // assertSyncerExistence asserts that a GossipSyncer exists for the given peer. func assertSyncerExistence(t *testing.T, syncMgr *SyncManager, peer *mockPeer) *GossipSyncer { t.Helper() s, ok := syncMgr.GossipSyncer(peer.PubKey()) if !ok { t.Fatalf("gossip syncer for peer %x not found", peer.PubKey()) } return s } // assertSyncerStatus asserts that the gossip syncer for the given peer matches // the expected sync state and type. func assertSyncerStatus(t *testing.T, s *GossipSyncer, syncState syncerState, syncType SyncerType) { t.Helper() // We'll check the status of our syncer within a WaitPredicate as some // sync transitions might cause this to be racy. err := wait.NoError(func() error { state := s.syncState() if s.syncState() != syncState { return fmt.Errorf("expected syncState %v for peer "+ "%x, got %v", syncState, s.cfg.peerPub, state) } typ := s.SyncType() if s.SyncType() != syncType { return fmt.Errorf("expected syncType %v for peer "+ "%x, got %v", syncType, s.cfg.peerPub, typ) } return nil }, time.Second) if err != nil { t.Fatal(err) } } // assertTransitionToChansSynced asserts the transition of an ActiveSync // GossipSyncer to its final chansSynced state. func assertTransitionToChansSynced(t *testing.T, s *GossipSyncer, peer *mockPeer) { t.Helper() query := &lnwire.QueryChannelRange{ FirstBlockHeight: 0, NumBlocks: math.MaxUint32, } assertMsgSent(t, peer, query) s.ProcessQueryMsg(&lnwire.ReplyChannelRange{ QueryChannelRange: *query, Complete: 1, }, nil) chanSeries := s.cfg.channelSeries.(*mockChannelGraphTimeSeries) select { case <-chanSeries.filterReq: chanSeries.filterResp <- nil case <-time.After(2 * time.Second): t.Fatal("expected to receive FilterKnownChanIDs request") } err := wait.NoError(func() error { state := syncerState(atomic.LoadUint32(&s.state)) if state != chansSynced { return fmt.Errorf("expected syncerState %v, got %v", chansSynced, state) } return nil }, time.Second) if err != nil { t.Fatal(err) } } // assertPassiveSyncerTransition asserts that a gossip syncer goes through all // of its expected steps when transitioning from passive to active. func assertPassiveSyncerTransition(t *testing.T, s *GossipSyncer, peer *mockPeer) { t.Helper() assertActiveGossipTimestampRange(t, peer) assertSyncerStatus(t, s, chansSynced, ActiveSync) } // assertActiveSyncerTransition asserts that a gossip syncer goes through all of // its expected steps when transitioning from active to passive. func assertActiveSyncerTransition(t *testing.T, s *GossipSyncer, peer *mockPeer) { t.Helper() assertMsgSent(t, peer, &lnwire.GossipTimestampRange{ FirstTimestamp: uint32(zeroTimestamp.Unix()), TimestampRange: 0, }) assertSyncerStatus(t, s, chansSynced, PassiveSync) }