How Python detects whether a remote UDP port is open _python

This example describes how Python detects whether a remote UDP port is open. Share to everyone for your reference. The implementation methods are as follows:

Copy Code code 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 this ICMP messages can only is 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 will help you with your Python programming.