I am trying to convert a group of IP ranges that can start and end on any given address, but not necessarily on a .0, .127, or .255, etc. I have code that is mostly working; however, it can be slow for large ranges.
For example find_range("1.40.0.0","1.44.255.255")
will take over a minute to return the correct result of 1.40.0.0/14
and 1.44.0.0/16
.
Also, I am have trouble when the starting range does not end with a .0. How can I fix these 2 issues: slowness on large IP ranges and when the starting range does not end in .0?
For the slowness problem, I tried skipping more than 1 address at a time, but then this would miss smaller ranges.
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...