
Implementation: Server side


very easy
recvfrom(2)
decode request
gettimeofday(2)
build reply
sendmsg(2)

oups, not that easy... we might reply with the wrong src address
many implementations will refuse our answer
listen on each individual IP, so we know which IP the request was sent to and can use that as src address when replying
use getifaddrs(3) to get the IPs

