There are now hundreds of these so I'll supply ONE example so you can find others.
http://www.amazon.com/dp/B00HZWOQZ6 does MANY things including turning an USB drive into a NAS connected drive.
I am using D link DIR 615 wireless N300 router, in this router I don’t have USB port inbuilt my question is I have external HDD with me is there any way to connect my HDD through USB to Ethernet adapter to my router for file sharing. Will it work? or any other way to connect?