用python實現ping

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#!/usr/bin/env python#coding=utf-8import os import argparse import socketimport structimport selectimport time  ICMP_ECHO_REQUEST = 8 # Platform specificDEFAULT_TIMEOUT = 2DEFAULT_COUNT = 4   class Pinger(object):    """       Pings to a host -- the Pythonic way    """    def __init__(self, target_host, count=DEFAULT_COUNT, timeout=DEFAULT_TIMEOUT):        self.target_host = target_host        self.count = count        self.timeout = timeout    def do_checksum(self, source_string):        """           Verify the packet integritity         """        sum = 0        max_count = (len(source_string)/2)*2        count = 0        while count < max_count:  # 分割資料每兩位元(16bit)為一組            val = ord(source_string[count + 1])*256 + ord(source_string[count])            sum = sum + val            sum = sum & 0xffffffff             count = count + 2             if max_count<len(source_string):  # 如果資料長度為基數,則將最後一位單獨相加            sum = sum + ord(source_string[len(source_string) - 1])            sum = sum & 0xffffffff              sum = (sum >> 16)  +  (sum & 0xffff)   # 將高16位與低16位相加直到高16位為0        sum = sum + (sum >> 16)        answer = ~sum        answer = answer & 0xffff        answer = answer >> 8 | (answer << 8 & 0xff00)        return answer   # 返回的是十進位整數    def receive_ping(self, sock, ID, timeout):        """        Receive ping from the socket.        """        time_remaining = timeout        while True:            start_time = time.time()            readable = select.select([sock], [], [], time_remaining)            time_spent = (time.time() - start_time)            if readable[0] == []: # Timeout                return                 time_received = time.time()            recv_packet, addr = sock.recvfrom(1024)            icmp_header = recv_packet[20:28]            type, code, checksum, packet_ID, sequence = struct.unpack(                "bbHHh", icmp_header            )            if packet_ID == ID:                bytes_In_double = struct.calcsize("d")                time_sent = struct.unpack("d", recv_packet[28:28 + bytes_In_double])[0]                return time_received - time_sent                 time_remaining = time_remaining - time_spent            if time_remaining <= 0:                return    def send_ping(self, sock, ID):        #Send ping to the target host        target_addr  =  socket.gethostbyname(self.target_host)             my_checksum = 0             # Create a dummy heder with a 0 checksum.        header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, my_checksum, ID, 1)        bytes_In_double = struct.calcsize("d")        data = (192 - bytes_In_double) * "Q"        data = struct.pack("d", time.time()) + data             # Get the checksum on the data and the dummy header.        my_checksum = self.do_checksum(header + data)        header = struct.pack(            "bbHHh", ICMP_ECHO_REQUEST, 0, socket.htons(my_checksum), ID, 1        )        packet = header + data        sock.sendto(packet, (target_addr, 1))    def ping_once(self):        """        Returns the delay (in seconds) or none on timeout.        """        icmp = socket.getprotobyname("icmp")        try:            sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)        except socket.error, (errno, msg):            if errno == 1:                # Not superuser, so operation not permitted                msg +=  "ICMP messages can only be sent from root user processes"                raise socket.error(msg)        except Exception, e:            print "Exception: %s" %(e)            my_ID = os.getpid() & 0xFFFF             self.send_ping(sock, my_ID)        delay = self.receive_ping(sock, my_ID, self.timeout)        sock.close()        return delay    def ping(self):        """        Run the ping process        """        for i in xrange(self.count):            print "Ping to %s..." % self.target_host,            try:                delay  =  self.ping_once()            except socket.gaierror, e:                print "Ping failed. (socket error: ‘%s‘)" % e[1]                break                 if delay  ==  None:                print "Ping failed. (timeout within %ssec.)" % self.timeout            else:                delay  =  delay * 1000                print "Get ping in %0.4fms" % delayif __name__ == ‘__main__‘:    parser = argparse.ArgumentParser(description=‘Python ping‘)    parser.add_argument(‘--target-host‘, action="store", dest="target_host", required=True)    given_args = parser.parse_args()      target_host = given_args.target_host    pinger = Pinger(target_host=target_host, count=5, timeout=5)    pinger.ping()

 

用python實現ping