discovery: adhere to proper channel chunk splitting for ReplyChannelRange

discovery/syncer_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"math"
 	"reflect"
+	"sort"
 	"sync"
 	"testing"
 	"time"
@@ -12,7 +13,9 @@ import (
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/davecgh/go-spew/spew"
+	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/stretchr/testify/require"
 )
 
 const (
@@ -95,11 +98,36 @@ func (m *mockChannelGraphTimeSeries) FilterKnownChanIDs(chain chainhash.Hash,
 	return <-m.filterResp, nil
 }
 func (m *mockChannelGraphTimeSeries) FilterChannelRange(chain chainhash.Hash,
-	startHeight, endHeight uint32) ([]lnwire.ShortChannelID, error) {
+	startHeight, endHeight uint32) ([]channeldb.BlockChannelRange, error) {
 
 	m.filterRangeReqs <- filterRangeReq{startHeight, endHeight}
+	reply := <-m.filterRangeResp
 
-	return <-m.filterRangeResp, nil
+	channelsPerBlock := make(map[uint32][]lnwire.ShortChannelID)
+	for _, cid := range reply {
+		channelsPerBlock[cid.BlockHeight] = append(
+			channelsPerBlock[cid.BlockHeight], cid,
+		)
+	}
+
+	// Return the channel ranges in ascending block height order.
+	blocks := make([]uint32, 0, len(channelsPerBlock))
+	for block := range channelsPerBlock {
+		blocks = append(blocks, block)
+	}
+	sort.Slice(blocks, func(i, j int) bool {
+		return blocks[i] < blocks[j]
+	})
+
+	channelRanges := make([]channeldb.BlockChannelRange, 0, len(channelsPerBlock))
+	for _, block := range blocks {
+		channelRanges = append(channelRanges, channeldb.BlockChannelRange{
+			Height:   block,
+			Channels: channelsPerBlock[block],
+		})
+	}
+
+	return channelRanges, nil
 }
 func (m *mockChannelGraphTimeSeries) FetchChanAnns(chain chainhash.Hash,
 	shortChanIDs []lnwire.ShortChannelID) ([]lnwire.Message, error) {
@@ -161,6 +189,7 @@ func newTestSyncer(hID lnwire.ShortChannelID,
 		bestHeight: func() uint32 {
 			return latestKnownHeight
 		},
+		maxQueryChanRangeReplies: maxQueryChanRangeReplies,
 	}
 	syncer := newGossipSyncer(cfg)
 
@@ -828,6 +857,7 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 	// reply. We should get three sets of messages as two of them should be
 	// full, while the other is the final fragment.
 	const numExpectedChunks = 3
+	var prevResp *lnwire.ReplyChannelRange
 	respMsgs := make([]lnwire.ShortChannelID, 0, 5)
 	for i := 0; i < numExpectedChunks; i++ {
 		select {
@@ -855,14 +885,14 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 			// channels.
 			case i == 0:
 				expectedFirstBlockHeight = startingBlockHeight
-				expectedNumBlocks = chunkSize + 1
+				expectedNumBlocks = 4
 
 			// The last reply should range starting from the next
 			// block of our previous reply up until the ending
 			// height of the query. It should also have the Complete
 			// bit set.
 			case i == numExpectedChunks-1:
-				expectedFirstBlockHeight = respMsgs[len(respMsgs)-1].BlockHeight
+				expectedFirstBlockHeight = prevResp.LastBlockHeight() + 1
 				expectedNumBlocks = endingBlockHeight - expectedFirstBlockHeight + 1
 				expectedComplete = 1
 
@@ -870,8 +900,8 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 			// the next block of our previous reply up until it
 			// reaches its maximum capacity of channels.
 			default:
-				expectedFirstBlockHeight = respMsgs[len(respMsgs)-1].BlockHeight
-				expectedNumBlocks = 5
+				expectedFirstBlockHeight = prevResp.LastBlockHeight() + 1
+				expectedNumBlocks = 4
 			}
 
 			switch {
@@ -889,9 +919,10 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 			case rangeResp.Complete != expectedComplete:
 				t.Fatalf("Complete in resp #%d incorrect: "+
 					"expected %v, got %v", i+1,
-					expectedNumBlocks, rangeResp.Complete)
+					expectedComplete, rangeResp.Complete)
 			}
 
+			prevResp = rangeResp
 			respMsgs = append(respMsgs, rangeResp.ShortChanIDs...)
 		}
 	}
@@ -1498,10 +1529,12 @@ func TestGossipSyncerDelayDOS(t *testing.T) {
 	// inherently disjoint.
 	var syncer2Chans []lnwire.ShortChannelID
 	for i := 0; i < numTotalChans; i++ {
-		syncer2Chans = append(syncer2Chans, lnwire.ShortChannelID{
-			BlockHeight: highestID.BlockHeight - 1,
-			TxIndex:     uint32(i),
-		})
+		syncer2Chans = append([]lnwire.ShortChannelID{
+			{
+				BlockHeight: highestID.BlockHeight - uint32(i) - 1,
+				TxIndex:     uint32(i),
+			},
+		}, syncer2Chans...)
 	}
 
 	// We'll kick off the test by asserting syncer1 sends over the
@@ -2305,3 +2338,80 @@ func TestGossipSyncerSyncedSignal(t *testing.T) {
 		t.Fatal("expected to receive chansSynced signal")
 	}
 }
+
+// TestGossipSyncerMaxChannelRangeReplies ensures that a gossip syncer
+// transitions its state after receiving the maximum possible number of replies
+// for a single QueryChannelRange message, and that any further replies after
+// said limit are not processed.
+func TestGossipSyncerMaxChannelRangeReplies(t *testing.T) {
+	t.Parallel()
+
+	msgChan, syncer, chanSeries := newTestSyncer(
+		lnwire.ShortChannelID{BlockHeight: latestKnownHeight},
+		defaultEncoding, defaultChunkSize,
+	)
+
+	// We'll tune the maxQueryChanRangeReplies to a more sensible value for
+	// the sake of testing.
+	syncer.cfg.maxQueryChanRangeReplies = 100
+
+	syncer.Start()
+	defer syncer.Stop()
+
+	// Upon initialization, the syncer should submit a QueryChannelRange
+	// request.
+	var query *lnwire.QueryChannelRange
+	select {
+	case msgs := <-msgChan:
+		require.Len(t, msgs, 1)
+		require.IsType(t, &lnwire.QueryChannelRange{}, msgs[0])
+		query = msgs[0].(*lnwire.QueryChannelRange)
+
+	case <-time.After(time.Second):
+		t.Fatal("expected query channel range request msg")
+	}
+
+	// We'll send the maximum number of replies allowed to a
+	// QueryChannelRange request with each reply consuming only one block in
+	// order to transition the syncer's state.
+	for i := uint32(0); i < syncer.cfg.maxQueryChanRangeReplies; i++ {
+		reply := &lnwire.ReplyChannelRange{
+			QueryChannelRange: *query,
+			ShortChanIDs: []lnwire.ShortChannelID{
+				{
+					BlockHeight: query.FirstBlockHeight + i,
+				},
+			},
+		}
+		reply.FirstBlockHeight = query.FirstBlockHeight + i
+		reply.NumBlocks = 1
+		require.NoError(t, syncer.ProcessQueryMsg(reply, nil))
+	}
+
+	// We should receive a filter request for the syncer's local channels
+	// after processing all of the replies. We'll send back a nil response
+	// indicating that no new channels need to be synced, so it should
+	// transition to its final chansSynced state.
+	select {
+	case <-chanSeries.filterReq:
+	case <-time.After(time.Second):
+		t.Fatal("expected local filter request of known channels")
+	}
+	select {
+	case chanSeries.filterResp <- nil:
+	case <-time.After(time.Second):
+		t.Fatal("timed out sending filter response")
+	}
+	assertSyncerStatus(t, syncer, chansSynced, ActiveSync)
+
+	// Finally, attempting to process another reply for the same query
+	// should result in an error.
+	require.Error(t, syncer.ProcessQueryMsg(&lnwire.ReplyChannelRange{
+		QueryChannelRange: *query,
+		ShortChanIDs: []lnwire.ShortChannelID{
+			{
+				BlockHeight: query.LastBlockHeight() + 1,
+			},
+		},
+	}, nil))
+}