Python's method of detecting whether a remote udp port is open

This article illustrates a python method for detecting whether a remote udp port is open. Share with you for your reference. The specific implementation method is as follows:

import socket

import threading

import time

import struct

import Queue

queue = Queue.Queue()

def udp_sender(ip,port):

    try:

        ADDR = (ip,port)

        sock_udp = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)

        sock_udp.sendto("abcd...",ADDR)

        sock_udp.close()

    except:

        pass

def icmp_receiver(ip,port):

    icmp = socket.getprotobyname("icmp")

    try:

        sock_icmp = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)

    except socket.error, (errno, msg):

        if errno == 1:

            # Operation not permitted

            msg = msg + (

                " - Note that ICMP messages can only be sent from processes"

                " running as root."

            )

            raise socket.error(msg)

        raise # raise the original error

    sock_icmp.settimeout(3)

    try:

        recPacket,addr = sock_icmp.recvfrom(64)

    except:

        queue.put(True)

        return

    icmpHeader = recPacket[20:28]

    icmpPort = int(recPacket.encode('hex')[100:104],16)

    head_type, code, checksum, packetID, sequence = struct.unpack(

            "bbHHh", icmpHeader

    )

    sock_icmp.close()

    if code == 3 and icmpPort == port and addr[0] == ip:

        queue.put(False)

    return

def checker_udp(ip,port):

    thread_udp = threading.Thread(target=udp_sender,args=(ip,port))

    thread_icmp = threading.Thread(target=icmp_receiver,args=(ip,port))

    thread_udp.daemon= True

    thread_icmp.daemon = True

    thread_icmp.start()

    time.sleep(0.1)

    thread_udp.start()
    thread_icmp.join()

    thread_udp.join()

    return queue.get(False)

if __name__ == '__main__':

    import sys

    print checker_udp(sys.argv[1],int(sys.argv[2]))

I hope this article has helped you with your Python programming.