python检测远程udp端口是否打开

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]))</pre>