Python 3.3中的ip地址网络

Question

我正在尝试转换一组IP范围，这些IP范围可以在任何给定的地址上开始和结束，但不一定在.0、.127或.255等上。我的代码大部分都在工作；但是，对于大范围，它可能会很慢。

例如，find_range("1.40.0.0","1.44.255.255")返回1.40.0.0/14和1.44.0.0/16的正确结果需要一分钟以上的时间。

此外，当起始范围不是以.0结束时，我也会遇到麻烦。我如何解决这两个问题:大IP范围慢和起始范围不是以.0结束？

对于速度慢的问题，我尝试一次跳过1个以上的地址，但这样会错过较小的范围。

import ipaddress, socket, struct

def ip2int(addr):                                                               
    return struct.unpack("!I", socket.inet_aton(addr))[0]                       

def int2ip(addr):                                                               
    return socket.inet_ntoa(struct.pack("!I", addr))        

def ipminus(ip, amount=1):
    tmp = ip2int(ip)
    return int2ip(tmp - amount)

def ipplus(ip):
    tmp = ip2int(ip)
    return int2ip(tmp + 1)

def cidr_notation(a,b):
    for mask in range(32, 6, -1):
        test = "%s/%s" % (a,mask)
        try:
            n = ipaddress.IPv4Network(test,False)
            if b == "%s" % (n.broadcast_address):
                return test
        except:
            pass
    return None

def split_range(a,b):
    a1 = ip2int(a)
    b1 = ip2int(b)

    needed = 1
    while needed:
        result = cidr_notation(a,b)
        if result:
            print( "* %16s\t%16s\t%16s" % (result, a, b))
            if ip2int(b) > b1:
                needed = 0
            else:
                a = ipplus(b)
                b = int2ip(b1)
        else:
            b = ipminus(b)

    return result

def find_range(x,y):
    result = cidr_notation(x,y)
    if result:
        print( "# %16s\t%16s\t%16s" % (result, x, y))
    else:
        split_range(x,y)

# main...
print("%16s\t%16s\t%16s" % ("mask","start","end"))
print("%16s\t%16s\t%16s" % ("----","-----","---"))

find_range("128.191.0.0","128.191.255.255") #fast
find_range("10.55.96.106","10.55.96.106") #fast
find_range("5.135.14.0","5.135.61.11") #slow
find_range("4.31.64.72","4.59.175.255") #does not work, how to fix?
find_range("1.40.0.0","1.44.255.255") #very slow
# 5000 more find_range() calls...

Answer 1

基于bsdlp的注释，这段代码变得更简单、更快！

    def find_range(x,y,c_code="",c_name=""):
    print()
    print("%29s\t%23s" % (x,y))
    print("%16s\t%16s\t%16s\t%4s\t%s" % ("mask","start","end","code","name"))
    print("%16s\t%16s\t%16s\t%4s\t%s" % ("----","-----","---","----","----"))

    result = ipaddress.summarize_address_range( ipaddress.IPv4Address(x), ipaddress.IPv4Address(y) )
    for entry in result:
        net = str( entry.network_address )
        bcast = str( entry.broadcast_address )
        print( "%16s\t%16s\t%16s\t%4s\t%s" % (entry, net, bcast,c_code,c_name))