That's still not easy enough to do. UDP is simple enough but doing TCP in those drivers is still a pain. There are DPDK with LWIP or with some BSD tacked on top but so far I didn't find something that I can just take for a ride in that area.

For the extreme cases you really want to control the packet allocation for receive and make the buffers your app uses be also used for the network transmit so you get a real zero-copy.