Real NIC drivers spend most of their time fiddling with bit fields. It's mostly about translating a hardware-agnostic version of a packet descriptor (mbuf, sk_b

Real NIC drivers spend most of their time fiddling with bit fields. It's mostly about translating a hardware-agnostic version of a packet descriptor (mbuf, sk_buffs, ...) into a hardware-specific DMA descriptor. If your driver copies memory you are doing something wrong.