単純なDNSのプロキシを書いてみた

クエリの最大長っていくつだろう？

require 'socket'

HOST = '8.8.8.8' # Google DNS Server

sock = UDPSocket.open
sock.bind('', 53)

def proxy(msg)
  s = UDPSocket.open
  s.send(msg, 0, HOST, 53)
  msg = s.recvfrom(1024)[0]
  s.close
  return msg
end

loop do
  msg, (afam, port, host, ip) = sock.recvfrom(1024)
  puts "recv: #{msg.inspect}"
  sock.send(proxy(msg), 0, ip, port)
end