Fix TimeStamp issue in the Gossip Syncer

channeldb/graph.go

@@ -2143,6 +2143,21 @@ func (c *ChannelGraph) FilterKnownChanIDs(chansInfo []ChannelUpdateInfo,
 					zombieIndex, scid,
 				)
 
+				// TODO(ziggie): Make sure that for the strict
+				// pruning case we compare the pubkeys and
+				// whether the right timestamp is not older than
+				// the `ChannelPruneExpiry`.
+				//
+				// NOTE: The timestamp data has no verification
+				// attached to it in the `ReplyChannelRange` msg
+				// so we are trusting this data at this point.
+				// However it is not critical because we are
+				// just removing the channel from the db when
+				// the timestamps are more recent. During the
+				// querying of the gossip msg verification
+				// happens as usual.
+				// However we should start punishing peers when
+				// they don't provide us honest data ?
 				isStillZombie := isZombieChan(
 					info.Node1UpdateTimestamp,
 					info.Node2UpdateTimestamp,
@@ -2211,6 +2226,29 @@ type ChannelUpdateInfo struct {
 	Node2UpdateTimestamp time.Time
 }
 
+// NewChannelUpdateInfo is a constructor which makes sure we initialize the
+// timestamps with zero seconds unix timestamp which equals
+// `January 1, 1970, 00:00:00 UTC` in case the value is `time.Time{}`.
+func NewChannelUpdateInfo(scid lnwire.ShortChannelID, node1Timestamp,
+	node2Timestamp time.Time) ChannelUpdateInfo {
+
+	chanInfo := ChannelUpdateInfo{
+		ShortChannelID:       scid,
+		Node1UpdateTimestamp: node1Timestamp,
+		Node2UpdateTimestamp: node2Timestamp,
+	}
+
+	if node1Timestamp.IsZero() {
+		chanInfo.Node1UpdateTimestamp = time.Unix(0, 0)
+	}
+
+	if node2Timestamp.IsZero() {
+		chanInfo.Node2UpdateTimestamp = time.Unix(0, 0)
+	}
+
+	return chanInfo
+}
+
 // BlockChannelRange represents a range of channels for a given block height.
 type BlockChannelRange struct {
 	// Height is the height of the block all of the channels below were
@@ -2284,9 +2322,9 @@ func (c *ChannelGraph) FilterChannelRange(startHeight,
 			rawCid := byteOrder.Uint64(k)
 			cid := lnwire.NewShortChanIDFromInt(rawCid)
 
-			chanInfo := ChannelUpdateInfo{
-				ShortChannelID: cid,
-			}
+			chanInfo := NewChannelUpdateInfo(
+				cid, time.Time{}, time.Time{},
+			)
 
 			if !withTimestamps {
 				channelsPerBlock[cid.BlockHeight] = append(

channeldb/graph_test.go

@@ -1980,9 +1980,9 @@ func TestFilterKnownChanIDs(t *testing.T) {
 			t.Fatalf("unable to create channel edge: %v", err)
 		}
 
-		chanIDs = append(chanIDs, ChannelUpdateInfo{
-			ShortChannelID: chanID,
-		})
+		chanIDs = append(chanIDs, NewChannelUpdateInfo(
+			chanID, time.Time{}, time.Time{},
+		))
 	}
 
 	const numZombies = 5
@@ -2024,20 +2024,28 @@ func TestFilterKnownChanIDs(t *testing.T) {
 		// should get the same set back.
 		{
 			queryIDs: []ChannelUpdateInfo{
-				{ShortChannelID: lnwire.ShortChannelID{
-					BlockHeight: 99,
-				}},
-				{ShortChannelID: lnwire.ShortChannelID{
-					BlockHeight: 100,
-				}},
+				{
+					ShortChannelID: lnwire.ShortChannelID{
+						BlockHeight: 99,
+					},
+				},
+				{
+					ShortChannelID: lnwire.ShortChannelID{
+						BlockHeight: 100,
+					},
+				},
 			},
 			resp: []ChannelUpdateInfo{
-				{ShortChannelID: lnwire.ShortChannelID{
-					BlockHeight: 99,
-				}},
-				{ShortChannelID: lnwire.ShortChannelID{
-					BlockHeight: 100,
-				}},
+				{
+					ShortChannelID: lnwire.ShortChannelID{
+						BlockHeight: 99,
+					},
+				},
+				{
+					ShortChannelID: lnwire.ShortChannelID{
+						BlockHeight: 100,
+					},
+				},
 			},
 		},
 
@@ -2419,7 +2427,7 @@ func TestFilterChannelRange(t *testing.T) {
 		)
 	)
 
-	updateTimeSeed := int64(1)
+	updateTimeSeed := time.Now().Unix()
 	maybeAddPolicy := func(chanID uint64, node *LightningNode,
 		node2 bool) time.Time {
 
@@ -2428,7 +2436,7 @@ func TestFilterChannelRange(t *testing.T) {
 			chanFlags = lnwire.ChanUpdateDirection
 		}
 
-		var updateTime time.Time
+		var updateTime = time.Unix(0, 0)
 		if rand.Int31n(2) == 0 {
 			updateTime = time.Unix(updateTimeSeed, 0)
 			err = graph.UpdateEdgePolicy(&models.ChannelEdgePolicy{
@@ -2456,11 +2464,16 @@ func TestFilterChannelRange(t *testing.T) {
 		)
 		require.NoError(t, graph.AddChannelEdge(&channel2))
 
+		chanInfo1 := NewChannelUpdateInfo(
+			chanID1, time.Time{}, time.Time{},
+		)
+		chanInfo2 := NewChannelUpdateInfo(
+			chanID2, time.Time{}, time.Time{},
+		)
 		channelRanges = append(channelRanges, BlockChannelRange{
 			Height: chanHeight,
 			Channels: []ChannelUpdateInfo{
-				{ShortChannelID: chanID1},
-				{ShortChannelID: chanID2},
+				chanInfo1, chanInfo2,
 			},
 		})
 
@@ -2471,20 +2484,17 @@ func TestFilterChannelRange(t *testing.T) {
 			time4 = maybeAddPolicy(channel2.ChannelID, node2, true)
 		)
 
+		chanInfo1 = NewChannelUpdateInfo(
+			chanID1, time1, time2,
+		)
+		chanInfo2 = NewChannelUpdateInfo(
+			chanID2, time3, time4,
+		)
 		channelRangesWithTimestamps = append(
 			channelRangesWithTimestamps, BlockChannelRange{
 				Height: chanHeight,
 				Channels: []ChannelUpdateInfo{
-					{
-						ShortChannelID:       chanID1,
-						Node1UpdateTimestamp: time1,
-						Node2UpdateTimestamp: time2,
-					},
-					{
-						ShortChannelID:       chanID2,
-						Node1UpdateTimestamp: time3,
-						Node2UpdateTimestamp: time4,
-					},
+					chanInfo1, chanInfo2,
 				},
 			},
 		)

discovery/gossiper.go

@@ -2745,6 +2745,22 @@ func (d *AuthenticatedGossiper) handleChanUpdate(nMsg *networkMsg,
 		return nil, true
 	}
 
+	// Check that the ChanUpdate is not too far into the future, this could
+	// reveal some faulty implementation therefore we log an error.
+	if time.Until(timestamp) > graph.DefaultChannelPruneExpiry {
+		log.Errorf("Skewed timestamp (%v) for edge policy of "+
+			"short_chan_id(%v), timestamp too far in the future: "+
+			"peer=%v, msg=%s, is_remote=%v", timestamp.Unix(),
+			shortChanID, nMsg.peer, nMsg.msg.MsgType(),
+			nMsg.isRemote,
+		)
+
+		nMsg.err <- fmt.Errorf("skewed timestamp of edge policy, "+
+			"timestamp too far in the future: %v", timestamp.Unix())
+
+		return nil, false
+	}
+
 	// Get the node pub key as far since we don't have it in the channel
 	// update announcement message. We'll need this to properly verify the
 	// message's signature.

discovery/sync_manager.go

@@ -561,7 +561,7 @@ func (m *SyncManager) removeGossipSyncer(peer route.Vertex) {
 		return
 	}
 
-	log.Debugf("Replaced active GossipSyncer(%x) with GossipSyncer(%x)",
+	log.Debugf("Replaced active GossipSyncer(%v) with GossipSyncer(%x)",
 		peer, newActiveSyncer.cfg.peerPub)
 }
 

discovery/syncer.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/graph"
 	"github.com/lightningnetwork/lnd/lnpeer"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"golang.org/x/time/rate"
@@ -787,6 +788,16 @@ func isLegacyReplyChannelRange(query *lnwire.QueryChannelRange,
 // reply to the initial range query to discover new channels that it didn't
 // previously know of.
 func (g *GossipSyncer) processChanRangeReply(msg *lnwire.ReplyChannelRange) error {
+	// isStale returns whether the timestamp is too far into the past.
+	isStale := func(timestamp time.Time) bool {
+		return time.Since(timestamp) > graph.DefaultChannelPruneExpiry
+	}
+
+	// isSkewed returns whether the timestamp is too far into the future.
+	isSkewed := func(timestamp time.Time) bool {
+		return time.Until(timestamp) > graph.DefaultChannelPruneExpiry
+	}
+
 	// If we're not communicating with a legacy node, we'll apply some
 	// further constraints on their reply to ensure it satisfies our query.
 	if !isLegacyReplyChannelRange(g.curQueryRangeMsg, msg) {
@@ -838,16 +849,42 @@ func (g *GossipSyncer) processChanRangeReply(msg *lnwire.ReplyChannelRange) erro
 	}
 
 	for i, scid := range msg.ShortChanIDs {
-		info := channeldb.ChannelUpdateInfo{
-			ShortChannelID: scid,
-		}
+		info := channeldb.NewChannelUpdateInfo(
+			scid, time.Time{}, time.Time{},
+		)
 
 		if len(msg.Timestamps) != 0 {
 			t1 := time.Unix(int64(msg.Timestamps[i].Timestamp1), 0)
 			info.Node1UpdateTimestamp = t1
 
 			t2 := time.Unix(int64(msg.Timestamps[i].Timestamp2), 0)
 			info.Node2UpdateTimestamp = t2
+
+			// Sort out all channels with outdated or skewed
+			// timestamps. Both timestamps need to be out of
+			// boundaries for us to skip the channel and not query
+			// it later on.
+			switch {
+			case isStale(info.Node1UpdateTimestamp) &&
+				isStale(info.Node2UpdateTimestamp):
+
+				continue
+
+			case isSkewed(info.Node1UpdateTimestamp) &&
+				isSkewed(info.Node2UpdateTimestamp):
+
+				continue
+
+			case isStale(info.Node1UpdateTimestamp) &&
+				isSkewed(info.Node2UpdateTimestamp):
+
+				continue
+
+			case isStale(info.Node2UpdateTimestamp) &&
+				isSkewed(info.Node1UpdateTimestamp):
+
+				continue
+			}
 		}
 
 		g.bufferedChanRangeReplies = append(