Ethernet at belt 12


int handler calls ether_input(), with pointers to
the interface the packet was received on
a struct ether_header (never used these days)
the mbuf from the RX ring
of course you noticed it is really an mbuf pointing to the mbuf cluster from the RX ring

ether_input does its ethernet magic

eventually figures out it is IPv4, queues our nice mbuf in ipintrq and asserts a "soft interrupt"