Merge pull request #7239 from Roasbeef/gossip-scoping-issues

discovery: ensure we prioritize sending out our own local announcements

discovery/gossiper.go

@@ -18,6 +18,7 @@ import (
 	"github.com/lightningnetwork/lnd/batch"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lnpeer"
@@ -826,6 +827,11 @@ type msgWithSenders struct {
 	// msg is the wire message itself.
 	msg lnwire.Message
 
+	// isLocal is true if this was a message that originated locally. We'll
+	// use this to bypass our normal checks to ensure we prioritize sending
+	// out our own updates.
+	isLocal bool
+
 	// sender is the set of peers that sent us this message.
 	senders map[route.Vertex]struct{}
 }
@@ -903,6 +909,7 @@ func (d *deDupedAnnouncements) addMsg(message networkMsg) {
 		if !ok {
 			mws = msgWithSenders{
 				msg:     msg,
+				isLocal: !message.isRemote,
 				senders: make(map[route.Vertex]struct{}),
 			}
 			mws.senders[sender] = struct{}{}
@@ -949,6 +956,7 @@ func (d *deDupedAnnouncements) addMsg(message networkMsg) {
 		if oldTimestamp < msg.Timestamp {
 			mws = msgWithSenders{
 				msg:     msg,
+				isLocal: !message.isRemote,
 				senders: make(map[route.Vertex]struct{}),
 			}
 
@@ -992,6 +1000,7 @@ func (d *deDupedAnnouncements) addMsg(message networkMsg) {
 		if oldTimestamp < msg.Timestamp {
 			mws = msgWithSenders{
 				msg:     msg,
+				isLocal: !message.isRemote,
 				senders: make(map[route.Vertex]struct{}),
 			}
 
@@ -1020,13 +1029,44 @@ func (d *deDupedAnnouncements) AddMsgs(msgs ...networkMsg) {
 	}
 }
 
+// msgsToBroadcast is returned by Emit() and partitions the messages we'd like
+// to broadcast next into messages that are locally sourced and those that are
+// sourced remotely.
+type msgsToBroadcast struct {
+	// localMsgs is the set of messages we created locally.
+	localMsgs []msgWithSenders
+
+	// remoteMsgs is the set of messages that we received from a remote
+	// party.
+	remoteMsgs []msgWithSenders
+}
+
+// addMsg adds a new message to the appropriate sub-slice.
+func (m *msgsToBroadcast) addMsg(msg msgWithSenders) {
+	if msg.isLocal {
+		m.localMsgs = append(m.localMsgs, msg)
+	} else {
+		m.remoteMsgs = append(m.remoteMsgs, msg)
+	}
+}
+
+// isEmpty returns true if the batch is empty.
+func (m *msgsToBroadcast) isEmpty() bool {
+	return len(m.localMsgs) == 0 && len(m.remoteMsgs) == 0
+}
+
+// length returns the length of the combined message set.
+func (m *msgsToBroadcast) length() int {
+	return len(m.localMsgs) + len(m.remoteMsgs)
+}
+
 // Emit returns the set of de-duplicated announcements to be sent out during
 // the next announcement epoch, in the order of channel announcements, channel
 // updates, and node announcements. Each message emitted, contains the set of
 // peers that sent us the message. This way, we can ensure that we don't waste
 // bandwidth by re-sending a message to the peer that sent it to us in the
 // first place. Additionally, the set of stored messages are reset.
-func (d *deDupedAnnouncements) Emit() []msgWithSenders {
+func (d *deDupedAnnouncements) Emit() msgsToBroadcast {
 	d.Lock()
 	defer d.Unlock()
 
@@ -1036,21 +1076,24 @@ func (d *deDupedAnnouncements) Emit() []msgWithSenders {
 
 	// Create an empty array of lnwire.Messages with a length equal to
 	// the total number of announcements.
-	msgs := make([]msgWithSenders, 0, numAnnouncements)
+	msgs := msgsToBroadcast{
+		localMsgs:  make([]msgWithSenders, 0, numAnnouncements),
+		remoteMsgs: make([]msgWithSenders, 0, numAnnouncements),
+	}
 
 	// Add the channel announcements to the array first.
 	for _, message := range d.channelAnnouncements {
-		msgs = append(msgs, message)
+		msgs.addMsg(message)
 	}
 
 	// Then add the channel updates.
 	for _, message := range d.channelUpdates {
-		msgs = append(msgs, message)
+		msgs.addMsg(message)
 	}
 
 	// Finally add the node announcements.
 	for _, message := range d.nodeAnnouncements {
-		msgs = append(msgs, message)
+		msgs.addMsg(message)
 	}
 
 	d.reset()
@@ -1096,26 +1139,83 @@ func splitAnnouncementBatches(subBatchSize int,
 	return splitAnnouncementBatch
 }
 
-// sendBatch broadcasts a list of announcements to our peers.
-func (d *AuthenticatedGossiper) sendBatch(announcementBatch []msgWithSenders) {
-	syncerPeers := d.syncMgr.GossipSyncers()
+// splitAndSendAnnBatch takes a batch of messages, computes the proper batch
+// split size, and then sends out all items to the set of target peers. If
+// isLocal is true, then we'll send them to all peers and skip any gossip
+// filter checks.
+func (d *AuthenticatedGossiper) splitAndSendAnnBatch(annBatch []msgWithSenders,
+	isLocal bool) {
 
-	// We'll first attempt to filter out this new message
-	// for all peers that have active gossip syncers
-	// active.
-	for _, syncer := range syncerPeers {
-		syncer.FilterGossipMsgs(announcementBatch...)
+	// Next, If we have new things to announce then broadcast them to all
+	// our immediately connected peers.
+	subBatchSize := calculateSubBatchSize(
+		d.cfg.TrickleDelay, d.cfg.SubBatchDelay,
+		d.cfg.MinimumBatchSize, len(annBatch),
+	)
+
+	splitAnnouncementBatch := splitAnnouncementBatches(
+		subBatchSize, annBatch,
+	)
+
+	d.wg.Add(1)
+	go func() {
+		defer d.wg.Done()
+
+		log.Infof("Broadcasting %v new announcements in %d sub "+
+			"batches (local=%v)", len(annBatch),
+			len(splitAnnouncementBatch), isLocal)
+
+		for _, announcementBatch := range splitAnnouncementBatch {
+			d.sendBatch(announcementBatch, isLocal)
+
+			select {
+			case <-time.After(d.cfg.SubBatchDelay):
+			case <-d.quit:
+				return
+			}
+		}
+	}()
+}
+
+// sendBatch broadcasts a list of announcements to our peers.
+func (d *AuthenticatedGossiper) sendBatch(annBatch []msgWithSenders,
+	isLocal bool) {
+
+	// If this is a batch of announcements created locally, then we can
+	// skip the filter and dedup logic below, and just send the
+	// announcements out to all our coonnected peers.
+	if isLocal {
+		msgsToSend := fn.Map(
+			annBatch, func(m msgWithSenders) lnwire.Message {
+				return m.msg
+			},
+		)
+		err := d.cfg.Broadcast(nil, msgsToSend...)
+		if err != nil {
+			log.Errorf("Unable to send local batch "+
+				"announcements: %v", err)
+		}
+
+		return
 	}
 
-	for _, msgChunk := range announcementBatch {
-		// With the syncers taken care of, we'll merge
-		// the sender map with the set of syncers, so
-		// we don't send out duplicate messages.
+	syncerPeers := d.syncMgr.GossipSyncers()
+
+	// We'll first attempt to filter out this new message for all peers
+	// that have active gossip syncers active.
+	for _, syncer := range syncerPeers {
+		syncer.FilterGossipMsgs(annBatch...)
+	}
+
+	for _, msgChunk := range annBatch {
+		msgChunk := msgChunk
+
+		// With the syncers taken care of, we'll merge the sender map
+		// with the set of syncers, so we don't send out duplicate
+		// messages.
 		msgChunk.mergeSyncerMap(syncerPeers)
 
-		err := d.cfg.Broadcast(
-			msgChunk.senders, msgChunk.msg,
-		)
+		err := d.cfg.Broadcast(msgChunk.senders, msgChunk.msg)
 		if err != nil {
 			log.Errorf("Unable to send batch "+
 				"announcements: %v", err)
@@ -1240,39 +1340,23 @@ func (d *AuthenticatedGossiper) networkHandler() {
 
 			// If the current announcements batch is nil, then we
 			// have no further work here.
-			if len(announcementBatch) == 0 {
+			if announcementBatch.isEmpty() {
 				continue
 			}
 
-			// Next, If we have new things to announce then
-			// broadcast them to all our immediately connected
-			// peers.
-			subBatchSize := calculateSubBatchSize(
-				d.cfg.TrickleDelay, d.cfg.SubBatchDelay, d.cfg.MinimumBatchSize,
-				len(announcementBatch),
+			// At this point, we have the set of local and remote
+			// announcements we want to send out. We'll do the
+			// batching as normal for both, but for local
+			// announcements, we'll blast them out w/o regard for
+			// our peer's policies so we ensure they propagate
+			// properly.
+			d.splitAndSendAnnBatch(
+				announcementBatch.localMsgs, true,
 			)
-
-			splitAnnouncementBatch := splitAnnouncementBatches(
-				subBatchSize, announcementBatch,
+			d.splitAndSendAnnBatch(
+				announcementBatch.remoteMsgs, false,
 			)
 
-			d.wg.Add(1)
-			go func() {
-				defer d.wg.Done()
-
-				log.Infof("Broadcasting %v new announcements in %d sub batches",
-					len(announcementBatch), len(splitAnnouncementBatch))
-
-				for _, announcementBatch := range splitAnnouncementBatch {
-					d.sendBatch(announcementBatch)
-					select {
-					case <-time.After(d.cfg.SubBatchDelay):
-					case <-d.quit:
-						return
-					}
-				}
-			}()
-
 		// The retransmission timer has ticked which indicates that we
 		// should check if we need to prune or re-broadcast any of our
 		// personal channels or node announcement. This addresses the
@@ -1611,8 +1695,9 @@ func (d *AuthenticatedGossiper) processChanPolicyUpdate(
 		// We set ourselves as the source of this message to indicate
 		// that we shouldn't skip any peers when sending this message.
 		chanUpdates = append(chanUpdates, networkMsg{
-			source: d.selfKey,
-			msg:    chanUpdate,
+			source:   d.selfKey,
+			isRemote: false,
+			msg:      chanUpdate,
 		})
 	}
 
@@ -2182,9 +2267,10 @@ func (d *AuthenticatedGossiper) handleNodeAnnouncement(nMsg *networkMsg,
 	// be broadcast to the rest of our peers.
 	if isPublic {
 		announcements = append(announcements, networkMsg{
-			peer:   nMsg.peer,
-			source: nMsg.source,
-			msg:    nodeAnn,
+			peer:     nMsg.peer,
+			isRemote: nMsg.isRemote,
+			source:   nMsg.source,
+			msg:      nodeAnn,
 		})
 	} else {
 		log.Tracef("Skipping broadcasting node announcement for %x "+
@@ -2460,9 +2546,10 @@ func (d *AuthenticatedGossiper) handleChanAnnouncement(nMsg *networkMsg,
 
 	if proof != nil {
 		announcements = append(announcements, networkMsg{
-			peer:   nMsg.peer,
-			source: nMsg.source,
-			msg:    ann,
+			peer:     nMsg.peer,
+			isRemote: nMsg.isRemote,
+			source:   nMsg.source,
+			msg:      ann,
 		})
 	}
 
@@ -2848,9 +2935,10 @@ func (d *AuthenticatedGossiper) handleChanUpdate(nMsg *networkMsg,
 	var announcements []networkMsg
 	if chanInfo.AuthProof != nil && !d.cfg.IsAlias(upd.ShortChannelID) {
 		announcements = append(announcements, networkMsg{
-			peer:   nMsg.peer,
-			source: nMsg.source,
-			msg:    upd,
+			peer:     nMsg.peer,
+			source:   nMsg.source,
+			isRemote: nMsg.isRemote,
+			msg:      upd,
 		})
 	}
 
@@ -2949,6 +3037,7 @@ func (d *AuthenticatedGossiper) handleAnnSig(nMsg *networkMsg,
 		} else {
 			remotePubKey = chanInfo.NodeKey1Bytes
 		}
+
 		// Since the remote peer might not be online we'll call a
 		// method that will attempt to deliver the proof when it comes
 		// online.

discovery/gossiper_test.go

@@ -824,6 +824,8 @@ func TestProcessAnnouncement(t *testing.T) {
 	require.NoError(t, err, "can't create context")
 
 	assertSenderExistence := func(sender *btcec.PublicKey, msg msgWithSenders) {
+		t.Helper()
+
 		if _, ok := msg.senders[route.NewVertex(sender)]; !ok {
 			t.Fatalf("sender=%x not present in %v",
 				sender.SerializeCompressed(), spew.Sdump(msg))
@@ -1910,31 +1912,37 @@ func TestDeDuplicatedAnnouncements(t *testing.T) {
 	// Ensure that announcement batch delivers channel announcements,
 	// channel updates, and node announcements in proper order.
 	batch := announcements.Emit()
-	if len(batch) != 4 {
+	if batch.length() != 4 {
 		t.Fatal("announcement batch incorrect length")
 	}
 
-	if !reflect.DeepEqual(batch[0].msg, ca2) {
+	if !reflect.DeepEqual(batch.localMsgs[0].msg, ca2) {
 		t.Fatalf("channel announcement not first in batch: got %v, "+
-			"expected %v", spew.Sdump(batch[0].msg), spew.Sdump(ca2))
+			"expected %v", spew.Sdump(batch.localMsgs[0].msg),
+			spew.Sdump(ca2))
 	}
 
-	if !reflect.DeepEqual(batch[1].msg, ua3) {
+	if !reflect.DeepEqual(batch.localMsgs[1].msg, ua3) {
 		t.Fatalf("channel update not next in batch: got %v, "+
-			"expected %v", spew.Sdump(batch[1].msg), spew.Sdump(ua2))
+			"expected %v", spew.Sdump(batch.localMsgs[1].msg),
+			spew.Sdump(ua2))
 	}
 
 	// We'll ensure that both node announcements are present. We check both
 	// indexes as due to the randomized order of map iteration they may be
 	// in either place.
-	if !reflect.DeepEqual(batch[2].msg, na) && !reflect.DeepEqual(batch[3].msg, na) {
+	if !reflect.DeepEqual(batch.localMsgs[2].msg, na) &&
+		!reflect.DeepEqual(batch.localMsgs[3].msg, na) {
+
 		t.Fatalf("first node announcement not in last part of batch: "+
-			"got %v, expected %v", batch[2].msg,
+			"got %v, expected %v", batch.localMsgs[2].msg,
 			na)
 	}
-	if !reflect.DeepEqual(batch[2].msg, na5) && !reflect.DeepEqual(batch[3].msg, na5) {
+	if !reflect.DeepEqual(batch.localMsgs[2].msg, na5) &&
+		!reflect.DeepEqual(batch.localMsgs[3].msg, na5) {
+
 		t.Fatalf("second node announcement not in last part of batch: "+
-			"got %v, expected %v", batch[3].msg,
+			"got %v, expected %v", batch.localMsgs[3].msg,
 			na5)
 	}
 

docs/release-notes/release-notes-0.16.0.md

@@ -1,5 +1,13 @@
 # Release Notes
 
+## Peer to Peer Behavior
+
+`lnd` will now [properly prioritize sending out gossip updates generated
+locally to all connected
+peers](https://github.com/lightningnetwork/lnd/pull/7239), regardless of their
+current gossip sync query status.
+
+
 ## BOLT Specs
 
 * Warning messages from peers are now recognized and

fn/stream.go

@@ -0,0 +1,13 @@
+package fn
+
+// Map takes an input slice, and applies the function f to each element,
+// yielding a new slice.
+func Map[T1, T2 any](s []T1, f func(T1) T2) []T2 {
+	r := make([]T2, len(s))
+
+	for i, v := range s {
+		r[i] = f(v)
+	}
+
+	return r
+}