我发布了Python find first network hop关于尝试找到第一跳的内容,我想的越多,它就越容易成为python中路由表的过程.我不是程序员,我不知道我在做什么. ：p

这就是我提出的,我注意到的第一个问题是环回接口没有显示在/ proc / net / route文件中 – 所以评估127.0.0.0/8会给你默认路由…对于我申请,没关系.

还有什么重要我忽略了吗？解析ip route get< ip>还是个好主意？

import re
import struct
import socket

'''
   Read all the routes into a list. Most specific first.
   # eth0  000219AC        04001EAC        0003    0       0       0       00FFFFFF ...
'''
def _RtTable():
    _rt = []
    rt_m = re.compile('^[a-z0-9]*\W([0-9A-F]{8})\W([0-9A-F]{8})[\W0-9]*([0-9A-F]{8})')
    rt = open('/proc/net/route', 'r')
    for line in rt.read().split('\n'):
        if rt_m.match(line):
            _rt.append(rt_m.findall(line)[0])

    rt.close()
    return _rt

'''
   Create a temp ip (tip) that is the entered ip with the host 
   section striped off.  Matching to routers in order, 
   the first match should be the most specific.

   If we get 0.0.0.0 as the next hop, the network is likely(?) 
   directly attached- the entered IP is the next (only) hop
'''
def FindGw(ip):
    int_ip = struct.unpack("I", socket.inet_aton(ip))[0]
    for entry in _RtTable():
        tip = int_ip & int(entry[2], 16)
        if tip == int(entry[0], 16):
            gw_s = socket.inet_ntoa(struct.pack("I", int(entry[1], 16)))
            if gw_s == '0.0.0.0':
                return ip
            else:
                return gw_s

if __name__ == '__main__':
    import sys
    print FindGw(sys.argv[1])

解决方法:

在proc文件系统的手册页中给出了它.

   /proc/net
          various net pseudo-files, all of which give the status of some part of
          the networking layer.  These files contain ASCII structures and  are,
          there‐fore, readable with cat(1).
          However, the standard netstat(8) suite provides much 
          cleaner access to these files.

只需依靠为这些目的设计的工具.使用netstat,traceroute或任何其他标准工具.使用子进程模块干净地包装这些命令,并获取您要查找的信息.