diff --git a/eth/fetcher/fetcher.go b/eth/fetcher/fetcher.go index d5ff5d77e..98170cf79 100644 --- a/eth/fetcher/fetcher.go +++ b/eth/fetcher/fetcher.go @@ -16,6 +16,7 @@ import ( const ( arriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested fetchTimeout = 5 * time.Second // Maximum alloted time to return an explicitly requested block + maxUncleDist = 7 // Maximum allowed backward distance from the chain head maxQueueDist = 256 // Maximum allowed distance from the chain head to queue ) @@ -202,7 +203,7 @@ func (f *Fetcher) loop() { break } // Otherwise if fresh and still unknown, try and import - if number <= height || f.getBlock(op.block.Hash()) != nil { + if number+maxUncleDist < height || f.getBlock(op.block.Hash()) != nil { continue } f.insert(op.origin, op.block) @@ -317,7 +318,7 @@ func (f *Fetcher) enqueue(peer string, block *types.Block) { hash := block.Hash() // Discard any past or too distant blocks - if dist := int64(block.NumberU64()) - int64(f.chainHeight()); dist <= 0 || dist > maxQueueDist { + if dist := int64(block.NumberU64()) - int64(f.chainHeight()); dist < -maxUncleDist || dist > maxQueueDist { glog.V(logger.Detail).Infof("Peer %s: discarded block #%d [%x], distance %d", peer, block.NumberU64(), hash.Bytes()[:4], dist) return }