Recently I encountered several questions on SO regarding working with sockets on a very low level. Here's an example. While looking for an answer, I realised that sockets have relatively low capabilities on OSI Level 2. On Linux, we can specify a protocol when creating a socket, but obviously not all Level 2 protocols are present in the list.
While it is possible to assemble and send an ethernet frame, it's (presumably) not possible to send a 802.11 packet - though it looks like wifi device drivers do convert ethernet frames to wifi packets and vice versa.
This made me wonder, if there are more possibilities in reading and writing directly to device files like eht0, ath0? Is it a socket implementation who usually writes to these files, or a device driver? And who's on receiving side - a NIC driver, a peripheral bus controller?
