(require :sb-posix)
(require :sb-bsd-sockets)

(defconstant data       "sup")
(defconstant port-min   1024)
(defconstant port-max   65535)

(setf *random-state* (make-random-state t))

(defun list-ip (ip &optional (start 0))
  (let ((pos (position #\. ip :start start)))
    (if pos
      (cons (parse-integer (subseq ip start pos))
            (list-ip ip (1+ pos)))
      (list (parse-integer (subseq ip start))))))

(defun parse-ip (ip)
  (make-array 4 :initial-contents (list-ip ip)))

(defun fmt-ip (ip)
  (format nil "~d.~d.~d.~d"
              (aref ip 0)
              (aref ip 1)
              (aref ip 2)
              (aref ip 3)))

(defun random-port ()
  (+ port-min (random (1+ (- port-max port-min)))))

(defun klok ()
  (/ (get-internal-real-time)
     internal-time-units-per-second))

(let ((loc-port (parse-integer (second *posix-argv*)))
      (rem-ip   (parse-ip      (third  *posix-argv*)))
      (interval (parse-integer (fourth *posix-argv*)))
      (sock     (make-instance 'sb-bsd-sockets:inet-socket
                               :type     :datagram
                               :protocol :udp))
      (start    (klok))
      (pak      0))

  (setf (sb-bsd-sockets:sockopt-reuse-address sock) t)
  (setf (sb-bsd-sockets:non-blocking-mode     sock) t)
  (sb-bsd-sockets:socket-bind sock #(0 0 0 0) loc-port)

  (defun send (str ip port)
    (sb-bsd-sockets:socket-send sock str (length str)
                                :address (list ip port)))

  (defun recv ()
    (sb-bsd-sockets:socket-receive sock nil 64))

  (format t "drilling pls wait...~%")
  (setf interval (/ interval 1000000))
  (loop
    (sleep interval)
    (send data rem-ip (random-port))
    (incf pak)
    (multiple-value-bind (buf len ip port) (recv)
      (when (string= (subseq buf 0 len) data)
        (format t "connected to ~a:~d in ~f sec with ~d packets sent~%"
                (fmt-ip ip)
                port
                (- (klok) start)
                pak)
        (dotimes (x 1000)
          (sleep interval)
          (send data ip port))
        (exit)))))