[雪峰磁针石博客]python网络作业：使用python的socket库实现ICMP协议的ping

末蓝、 2022-02-13 05:29 172阅读 0赞

ICMP ping是您遇到过的最常见的网络扫描类型。 打开命令行提示符或终端并输入ping www.google.com非常容易。

为什么要在python中实现？

*  很多名牌大学喜欢考试用python的socket库实现ICMP协议的ping
 *  个别环境没有ping

直接上代码：

#!/usr/bin/python3
    # -*- coding: utf-8 -*-
    # 技术支持：https://www.jianshu.com/u/69f40328d4f0 
    # 技术支持 https://china-testing.github.io/
    # https://github.com/china-testing/python-api-tesing/blob/master/practices/ping.py
    # 讨论钉钉免费群21745728 qq群144081101 567351477
    # CreateDate: 2018-11-22
    
    import os 
    import argparse 
    import socket
    import struct
    import select
    import time
    
    
    ICMP_ECHO_REQUEST = 8 # Platform specific
    DEFAULT_TIMEOUT = 2
    DEFAULT_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:
    
                val = source_string[count + 1]*256 + source_string[count]                   
                sum = sum + val
                sum = sum & 0xffffffff 
                count = count + 2
    
            if max_count<len(source_string):
                sum = sum + ord(source_string[len(source_string) - 1])
                sum = sum & 0xffffffff 
    
            sum = (sum >> 16)  +  (sum & 0xffff)
            sum = sum + (sum >> 16)
            answer = ~sum
            answer = answer & 0xffff
            answer = answer >> 8 | (answer << 8 & 0xff00)
            return answer
    
        def receive_pong(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()) + bytes(data.encode('utf-8'))
    
            # 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 as e:
                if e.errno == 1:
                    # Not superuser, so operation not permitted
                    e.msg +=  "ICMP messages can only be sent from root user processes"
                    raise socket.error(e.msg)
            except Exception as e:
                print ("Exception: %s" %(e))
    
            my_ID = os.getpid() & 0xFFFF
    
            self.send_ping(sock, my_ID)
            delay = self.receive_pong(sock, my_ID, self.timeout)
            sock.close()
            return delay
    
    
        def ping(self):
            """
            Run the ping process
            """
            for i in range(self.count):
                print ("Ping to %s..." % self.target_host,)
                try:
                    delay  =  self.ping_once()
                except socket.gaierror as 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 pong in %0.4fms" % delay)
    
    
    
    if __name__ == '__main__':
        parser = argparse.ArgumentParser(description='Python ping')
        parser.add_argument('host', action="store", help=u'主机名')
        given_args = parser.parse_args()  
        target_host = given_args.host
        pinger = Pinger(target_host=target_host)
        pinger.ping()

### 参考资料 ###

*  [本文最新版本地址][Link 1]
 *  讨论 钉钉群21745728 qq群144081101 567351477
 *  [本文涉及的python测试开发库][python] 谢谢点赞！
 *  [本文相关海量书籍下载][Link 2]
 *  [python 3.7极速入门教程9最佳python中文工具书籍下载][python 3.7_9_python]
 *  [最新代码地址][Link 3]

### 执行 ###

注意要有root或管理员权限：

# python3 ping.py china-testing.github.io
    Ping to china-testing.github.io...
    Get pong in 160.7175ms
    Ping to china-testing.github.io...
    Get pong in 160.8465ms
    Ping to china-testing.github.io...
    Get pong in 12.0983ms
    Ping to china-testing.github.io...
    Get pong in 161.3324ms
    # python3 ping.py www.so.com
    Ping to www.so.com...
    Get pong in 29.0303ms
    Ping to www.so.com...
    Get pong in 28.8599ms
    Ping to www.so.com...
    Get pong in 28.9860ms
    Ping to www.so.com...
    Get pong in 29.0167ms

[Link 1]: https://china-testing.github.io/network_ping.html
[python]: https://github.com/china-testing/python-api-tesing
[Link 2]: https://github.com/china-testing/python-api-tesing/blob/master/books.md
[python 3.7_9_python]: https://china-testing.github.io/python3_quick9.html
[Link 3]: https://github.com/china-testing/python-api-tesing/blob/master/practices/ping.py