Fix a problem where, when ndhc is waiting for an arp packet, an arp packet is received that is discarded by ndhc's basic checks and provokes a busy loop in the main program loop because epoll_wait() constantly sees data that is never drained from the socket buffer since arp_offset exceeds the maximum size of an ARP packet and would overflow the packet buffer.
Fix a problem where, when ndhc is waiting for an arp packet, an arp packet
is received that is discarded by ndhc's basic checks and provokes a busy
loop in the main program loop because epoll_wait() constantly sees data that
is never drained from the socket buffer since arp_offset exceeds the
maximum size of an ARP packet and would overflow the packet buffer.

niklata/ndhc