From 3657a1d612b5a057aa12fc6221572d781a50233b Mon Sep 17 00:00:00 2001
From: Rongjian Lan <rongjian.lan@gmail.com>
Date: Thu, 13 Jan 2022 21:52:22 -0800
Subject: [PATCH] reject old viewid (#3992)

---
 node/node.go | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/node/node.go b/node/node.go
index dbfcd701d..9071a6230 100644
--- a/node/node.go
+++ b/node/node.go
@@ -375,6 +375,7 @@ type withError struct {
 var (
 	errNotRightKeySize   = errors.New("key received over wire is wrong size")
 	errNoSenderPubKey    = errors.New("no sender public BLS key in message")
+	errViewIDTooOld      = errors.New("view id too old")
 	errWrongSizeOfBitmap = errors.New("wrong size of sender bitmap")
 	errWrongShardID      = errors.New("wrong shard id")
 	errInvalidNodeMsg    = errors.New("invalid node message")
@@ -425,6 +426,10 @@ func (node *Node) validateNodeMessage(ctx context.Context, payload []byte) (
 					utils.Logger().Debug().Uint64("receivedNum", block.NumberU64()).
 						Uint64("currentNum", curBeaconHeight).Msg("beacon block sync message rejected")
 					return nil, 0, errors.New("beacon block height smaller than current height beyond tolerance")
+				} else if block.NumberU64()-beaconBlockHeightTolerance > curBeaconHeight {
+					utils.Logger().Debug().Uint64("receivedNum", block.NumberU64()).
+						Uint64("currentNum", curBeaconHeight).Msg("beacon block sync message rejected")
+					return nil, 0, errors.New("beacon block height too much higher than current height beyond tolerance")
 				} else if block.NumberU64() <= curBeaconHeight {
 					utils.Logger().Debug().Uint64("receivedNum", block.NumberU64()).
 						Uint64("currentNum", curBeaconHeight).Msg("beacon block sync message ignored")
@@ -535,12 +540,20 @@ func (node *Node) validateShardBoundMessage(
 		if len(maybeCon.SenderPubkeyBitmap) > 0 {
 			senderBitmap = maybeCon.SenderPubkeyBitmap
 		}
+		// If the viewID is too old, reject the message.
+		if maybeCon.ViewId+5 < node.Consensus.GetCurBlockViewID() {
+			return nil, nil, true, errors.WithStack(errViewIDTooOld)
+		}
 	} else if maybeVC != nil {
 		if maybeVC.ShardId != node.Consensus.ShardID {
 			nodeConsensusMessageCounterVec.With(prometheus.Labels{"type": "invalid_shard"}).Inc()
 			return nil, nil, true, errors.WithStack(errWrongShardID)
 		}
 		senderKey = maybeVC.SenderPubkey
+		// If the viewID is too old, reject the message.
+		if maybeVC.ViewId+5 < node.Consensus.GetViewChangingID() {
+			return nil, nil, true, errors.WithStack(errViewIDTooOld)
+		}
 	} else {
 		nodeConsensusMessageCounterVec.With(prometheus.Labels{"type": "invalid"}).Inc()
 		return nil, nil, true, errors.WithStack(errNoSenderPubKey)