Title: ip_port_arrive()

For a given packet, ip_port_arrive() finds the ip file descriptors that are interested in the packet. ip_port_arrive() then hands the packet off to the higher layer (e.g., udp layer) by calling either packet2user() or a protocol-specific function (e.g., udp_ip_arrived()).

eth_arrive() is the function analogous to ip_port_arrive() on the ethernet layer. eth_arrive() tries to find interested ethernet file descriptors for a given packet.