Merge pull request #9011 from ziggie1984/fix-gossip-syncer

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) {
@@ -838,9 +849,9 @@ 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)
@@ -848,6 +859,32 @@ func (g *GossipSyncer) processChanRangeReply(msg *lnwire.ReplyChannelRange) erro
 
 			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(

discovery/syncer_test.go

@@ -1229,6 +1229,12 @@ func testGossipSyncerProcessChanRangeReply(t *testing.T, legacy bool) {
 	query, err := syncer.genChanRangeQuery(true)
 	require.NoError(t, err, "unable to generate channel range query")
 
+	currentTimestamp := time.Now().Unix()
+	// Timestamp more than 2 weeks in the past hence expired.
+	expiredTimestamp := time.Unix(0, 0).Unix()
+	// Timestamp three weeks in the future.
+	skewedTimestamp := time.Now().Add(time.Hour * 24 * 18).Unix()
+
 	// When interpreting block ranges, the first reply should start from
 	// our requested first block, and the last should end at our requested
 	// last block.
@@ -1253,14 +1259,78 @@ func testGossipSyncerProcessChanRangeReply(t *testing.T, legacy bool) {
 		},
 		{
 			FirstBlockHeight: 12,
-			NumBlocks:        query.NumBlocks - 12,
-			Complete:         1,
+			NumBlocks:        1,
 			ShortChanIDs: []lnwire.ShortChannelID{
 				{
 					BlockHeight: 12,
 				},
 			},
 		},
+		{
+			FirstBlockHeight: 13,
+			NumBlocks:        query.NumBlocks - 13,
+			Complete:         1,
+			ShortChanIDs: []lnwire.ShortChannelID{
+				{
+					BlockHeight: 13,
+					TxIndex:     1,
+				},
+				{
+					BlockHeight: 13,
+					TxIndex:     2,
+				},
+				{
+					BlockHeight: 13,
+					TxIndex:     3,
+				},
+				{
+					BlockHeight: 13,
+					TxIndex:     4,
+				},
+				{
+					BlockHeight: 13,
+					TxIndex:     5,
+				},
+				{
+					BlockHeight: 13,
+					TxIndex:     6,
+				},
+			},
+			Timestamps: []lnwire.ChanUpdateTimestamps{
+				{
+					// Both timestamps are valid.
+					Timestamp1: uint32(currentTimestamp),
+					Timestamp2: uint32(currentTimestamp),
+				},
+				{
+					// One of the timestamps is valid.
+					Timestamp1: uint32(currentTimestamp),
+					Timestamp2: uint32(expiredTimestamp),
+				},
+				{
+					// Both timestamps are expired.
+					Timestamp1: uint32(expiredTimestamp),
+					Timestamp2: uint32(expiredTimestamp),
+				},
+				{
+					// Both timestamps are skewed.
+					Timestamp1: uint32(skewedTimestamp),
+					Timestamp2: uint32(skewedTimestamp),
+				},
+				{
+					// One timestamp is skewed the other
+					// expired.
+					Timestamp1: uint32(expiredTimestamp),
+					Timestamp2: uint32(skewedTimestamp),
+				},
+				{
+					// One timestamp is skewed the other
+					// expired.
+					Timestamp1: uint32(skewedTimestamp),
+					Timestamp2: uint32(expiredTimestamp),
+				},
+			},
+		},
 	}
 
 	// Each reply query is the same as the original query in the legacy
@@ -1274,6 +1344,9 @@ func testGossipSyncerProcessChanRangeReply(t *testing.T, legacy bool) {
 
 		replies[2].FirstBlockHeight = query.FirstBlockHeight
 		replies[2].NumBlocks = query.NumBlocks
+
+		replies[3].FirstBlockHeight = query.FirstBlockHeight
+		replies[3].NumBlocks = query.NumBlocks
 	}
 
 	// We'll begin by sending the syncer a set of non-complete channel
@@ -1284,6 +1357,9 @@ func testGossipSyncerProcessChanRangeReply(t *testing.T, legacy bool) {
 	if err := syncer.processChanRangeReply(replies[1]); err != nil {
 		t.Fatalf("unable to process reply: %v", err)
 	}
+	if err := syncer.processChanRangeReply(replies[2]); err != nil {
+		t.Fatalf("unable to process reply: %v", err)
+	}
 
 	// At this point, we should still be in our starting state as the query
 	// hasn't finished.
@@ -1301,6 +1377,14 @@ func testGossipSyncerProcessChanRangeReply(t *testing.T, legacy bool) {
 		{
 			BlockHeight: 12,
 		},
+		{
+			BlockHeight: 13,
+			TxIndex:     1,
+		},
+		{
+			BlockHeight: 13,
+			TxIndex:     2,
+		},
 	}
 
 	// As we're about to send the final response, we'll launch a goroutine
@@ -1335,7 +1419,7 @@ func testGossipSyncerProcessChanRangeReply(t *testing.T, legacy bool) {
 
 	// If we send the final message, then we should transition to
 	// queryNewChannels as we've sent a non-empty set of new channels.
-	if err := syncer.processChanRangeReply(replies[2]); err != nil {
+	if err := syncer.processChanRangeReply(replies[3]); err != nil {
 		t.Fatalf("unable to process reply: %v", err)
 	}
 

docs/release-notes/release-notes-0.18.3.md

@@ -63,6 +63,10 @@ commitment when the channel was force closed.
 * [A bug has been fixed that could cause invalid channel
   announcements](https://github.com/lightningnetwork/lnd/pull/9002) to be
   generated if the inbound fee discount is used.
+  
+* [Fixed](https://github.com/lightningnetwork/lnd/pull/9011) a timestamp issue
+  in the `ReplyChannelRange` msg and introduced a check that ChanUpdates with a
+  timestamp too far into the future will be discarded.
 
 # New Features
 ## Functional Enhancements