Added fetcher limit for block imports as a DDos prevention mechanism

alejoacosta74 · Sep 12, 2023 · ff5b5e1 · ff5b5e1
1 parent c45b913
commit ff5b5e1
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/eth/fetcher/block_fetcher.go b/eth/fetcher/block_fetcher.go
@@ -350,7 +350,12 @@ func (f *BlockFetcher) loop() {
 				f.forgetBlock(hash)
 				continue
 			}
-			f.importBlocks(op.origin, op.block)
+
+			// Only import blocks using the Fetcher if its within maxUncleDist
+			// This is done to prevent DDos on the append queue
+			if op != nil && op.block.NumberU64()+maxUncleDist > f.chainHeight() {
+				f.importBlocks(op.origin, op.block)
+			}
 		}
 		// Wait for an outside event to occur
 		select {