Merge pull request #3785 from Roasbeef/gossip-queries-fix

discovery: properly set FirstBlockHeight and NumBlocks in responses

discovery/syncer.go

@@ -824,6 +824,14 @@ func (g *GossipSyncer) replyChanRangeQuery(query *lnwire.QueryChannelRange) erro
 	// TODO(roasbeef): means can't send max uint above?
 	//  * or make internal 64
 
+	// In the base case (no actual response) the first block and the last
+	// block in the query will be the same. In the loop below, we'll update
+	// these two variables incrementally with each chunk to properly
+	// compute the starting block for each response and the number of
+	// blocks in a response.
+	firstBlockHeight := query.FirstBlockHeight
+	lastBlockHeight := query.FirstBlockHeight
+
 	numChannels := int32(len(channelRange))
 	numChansSent := int32(0)
 	for {
@@ -854,13 +862,31 @@ func (g *GossipSyncer) replyChanRangeQuery(query *lnwire.QueryChannelRange) erro
 				"size=%v", g.cfg.peerPub[:], len(channelChunk))
 		}
 
+		// If we have any channels at all to return, then we need to
+		// update our pointers to the first and last blocks for each
+		// response.
+		if len(channelChunk) > 0 {
+			firstBlockHeight = channelChunk[0].BlockHeight
+			lastBlockHeight = channelChunk[len(channelChunk)-1].BlockHeight
+		}
+
+		// The number of blocks contained in this response (the total
+		// span) is the difference between the last channel ID and the
+		// first in the range. We add one as even if all channels
+		// returned are in the same block, we need to count that.
+		numBlocksInResp := lastBlockHeight - firstBlockHeight + 1
+
 		// With our chunk assembled, we'll now send to the remote peer
 		// the current chunk.
 		replyChunk := lnwire.ReplyChannelRange{
-			QueryChannelRange: *query,
-			Complete:          0,
-			EncodingType:      g.cfg.encodingType,
-			ShortChanIDs:      channelChunk,
+			QueryChannelRange: lnwire.QueryChannelRange{
+				ChainHash:        query.ChainHash,
+				NumBlocks:        numBlocksInResp,
+				FirstBlockHeight: firstBlockHeight,
+			},
+			Complete:     0,
+			EncodingType: g.cfg.encodingType,
+			ShortChanIDs: channelChunk,
 		}
 		if isFinalChunk {
 			replyChunk.Complete = 1

discovery/syncer_test.go

@@ -709,20 +709,31 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 
 	// Next, we'll craft a query to ask for all the new chan ID's after
 	// block 100.
+	const startingBlockHeight int = 100
 	query := &lnwire.QueryChannelRange{
-		FirstBlockHeight: 100,
+		FirstBlockHeight: uint32(startingBlockHeight),
 		NumBlocks:        50,
 	}
 
 	// We'll then launch a goroutine to reply to the query with a set of 5
 	// responses. This will ensure we get two full chunks, and one partial
 	// chunk.
-	resp := []lnwire.ShortChannelID{
-		lnwire.NewShortChanIDFromInt(1),
-		lnwire.NewShortChanIDFromInt(2),
-		lnwire.NewShortChanIDFromInt(3),
-		lnwire.NewShortChanIDFromInt(4),
-		lnwire.NewShortChanIDFromInt(5),
+	queryResp := []lnwire.ShortChannelID{
+		{
+			BlockHeight: uint32(startingBlockHeight),
+		},
+		{
+			BlockHeight: 102,
+		},
+		{
+			BlockHeight: 104,
+		},
+		{
+			BlockHeight: 106,
+		},
+		{
+			BlockHeight: 108,
+		},
 	}
 
 	errCh := make(chan error, 1)
@@ -740,7 +751,7 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 
 			// If the proper request was sent, then we'll respond
 			// with our set of short channel ID's.
-			chanSeries.filterRangeResp <- resp
+			chanSeries.filterRangeResp <- queryResp
 			errCh <- nil
 		}
 	}()
@@ -767,16 +778,52 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 				t.Fatalf("expected ReplyChannelRange instead got %T", msg)
 			}
 
+			// Only for the first iteration do we set the offset to
+			// zero as no chunks have been processed yet. For every
+			// other iteration, we want to move forward by the
+			// chunkSize (from the staring block height).
+			offset := 0
+			if i != 0 {
+				offset = 1
+			}
+			expectedFirstBlockHeight := (i+offset)*2 + startingBlockHeight
+
+			switch {
 			// If this is not the last chunk, then Complete should
 			// be set to zero. Otherwise, it should be one.
-			switch {
 			case i < 2 && rangeResp.Complete != 0:
 				t.Fatalf("non-final chunk should have "+
 					"Complete=0: %v", spew.Sdump(rangeResp))
 
+			case i < 2 && rangeResp.NumBlocks != chunkSize+1:
+				t.Fatalf("NumBlocks fields in resp "+
+					"incorrect: expected %v got %v",
+					chunkSize+1, rangeResp.NumBlocks)
+
+			case i < 2 && rangeResp.FirstBlockHeight !=
+				uint32(expectedFirstBlockHeight):
+
+				t.Fatalf("FirstBlockHeight incorrect: "+
+					"expected %v got %v",
+					rangeResp.FirstBlockHeight,
+					expectedFirstBlockHeight)
 			case i == 2 && rangeResp.Complete != 1:
 				t.Fatalf("final chunk should have "+
 					"Complete=1: %v", spew.Sdump(rangeResp))
+
+			case i == 2 && rangeResp.NumBlocks != 1:
+				t.Fatalf("NumBlocks fields in resp "+
+					"incorrect: expected %v got %v", 1,
+					rangeResp.NumBlocks)
+
+			case i == 2 && rangeResp.FirstBlockHeight !=
+				queryResp[len(queryResp)-1].BlockHeight:
+
+				t.Fatalf("FirstBlockHeight incorrect: "+
+					"expected %v got %v",
+					rangeResp.FirstBlockHeight,
+					queryResp[len(queryResp)-1].BlockHeight)
+
 			}
 
 			respMsgs = append(respMsgs, rangeResp.ShortChanIDs...)
@@ -785,13 +832,13 @@ func TestGossipSyncerReplyChanRangeQuery(t *testing.T) {
 
 	// We should get back exactly 5 short chan ID's, and they should match
 	// exactly the ID's we sent as a reply.
-	if len(respMsgs) != len(resp) {
+	if len(respMsgs) != len(queryResp) {
 		t.Fatalf("expected %v chan ID's, instead got %v",
-			len(resp), spew.Sdump(respMsgs))
+			len(queryResp), spew.Sdump(respMsgs))
 	}
-	if !reflect.DeepEqual(resp, respMsgs) {
+	if !reflect.DeepEqual(queryResp, respMsgs) {
 		t.Fatalf("mismatched response: expected %v, got %v",
-			spew.Sdump(resp), spew.Sdump(respMsgs))
+			spew.Sdump(queryResp), spew.Sdump(respMsgs))
 	}
 
 	// Wait for error from goroutine.