AsyncDNS-cr  Diff

      sock : UDPSocket
      case used_ns.family
      when Socket::Family::INET6
        if @v6_sock.nil?
          @v6_sock = s = UDPSocket.new
          s.bind "::", 0
          start_recv_loop(s)
        end
        sock = @v6_sock.not_nil!
      when Socket::Family::INET
        if @v4_sock.nil?
          @v4_sock = s = UDPSocket.new
          s.bind "0.0.0.0", 0
          start_recv_loop(s)
        end
        sock = @v4_sock.not_nil!
      else
        raise ArgumentError.new("Nameserver must be INET or INET6")
      end
      sock.send(context.raw_data, used_ns)
    end

    def start_recv_loop(sock : UDPSocket) : Nil
      spawn do
        buf = Bytes.new(0x10000)

        until sock.closed?
          begin
            len, addr = sock.receive(buf)
          rescue ex : IO::Error
            p ex
            break if sock.closed? && ex.os_error.nil?
            raise ex
          end
          handle_packet(buf[0, len], addr)
        end
      end
    end

    def handle_packet(packet : Bytes, sender : Socket::IPAddress)
      p packet
    end

    def stop : Nil
      # TODO
      @v6_sock.try { |s| s.close }
      @v4_sock.try { |s| s.close }
    end
  end
end