Check to see if an IP address is in a range in Redis

ip_range_lookup.py

#!/usr/bin/python3

import redis, ipaddress

r = redis.Redis(host='localhost', port=6379)

def ip2long(ip):
    """
    Convert an IP string to long
    """
    return int(ipaddress.ip_address(ip))

def getbclass(ip):
    """
    Return the Class B for an address
    """
    return '.'.join(ip.split('.')[0:2])


def fillincidr(cidr):
    """
    takes a CIDR range and adds it to the sorted sets
    """
    net4 = ipaddress.ip_network(cidr)
    bclass = getbclass(str(net4.network_address))

    r.zadd(bclass, {
        cidr+"_min": int(net4.network_address),
        cidr+"_max": int(net4.broadcast_address)
        })


def get_cidr(ip):
    """
    Determine if we have a known ip from a range
    """
    bclass = getbclass(ip)
    pipe = r.pipeline()
    pipe.zrevrangebyscore(bclass, ip2long(ip), '-inf', start=0, num=1)
    pipe.zrangebyscore(bclass, ip2long(ip), '+inf', start=0, num=1)
    results = pipe.execute()
    try:
        max = results[0][0].decode("utf-8")
        min = results[1][0].decode("utf-8")
        if max.split('_')[0] == min.split('_')[0]:
            return min.split('_')[0]
        else:
            return(-1)
    except:
        return(-1)
    

myrange  = "10.10.0.0/24"
myrange1  = "10.10.1.0/24"
fillincidr(myrange)
fillincidr(myrange1)
myipbad  = "10.10.2.123"
myipgood = "10.10.0.255"

print(myipgood, get_cidr(myipgood))
print(myipbad, get_cidr(myipbad))