Given an ip address (say 192.168.0.1), how do I check if it's in a network (say 192.168.0.0/24) in Python?
Are there general tools in Python for ip address manipulation? Stuff like host lookups, ip adddress to int, network address with netmask to int and so on? Hopefully in the standard Python library for 2.5.
This article shows you can do it with socket and struct modules without too much extra effort. I added a little to the article as follows:
import socket,struct
def makeMask(n):
"return a mask of n bits as a long integer"
return (2L<<n-1) - 1
def dottedQuadToNum(ip):
"convert decimal dotted quad string to long integer"
return struct.unpack('L',socket.inet_aton(ip))[0]
def networkMask(ip,bits):
"Convert a network address to a long integer"
return dottedQuadToNum(ip) & makeMask(bits)
def addressInNetwork(ip,net):
"Is an address in a network"
return ip & net == net
address = dottedQuadToNum("192.168.1.1")
networka = networkMask("10.0.0.0",24)
networkb = networkMask("192.168.0.0",24)
print (address,networka,networkb)
print addressInNetwork(address,networka)
print addressInNetwork(address,networkb)
This outputs:
False
True
If you just want a single function that takes strings it would look like this:
import socket,struct
def addressInNetwork(ip,net):
"Is an address in a network"
ipaddr = struct.unpack('L',socket.inet_aton(ip))[0]
netaddr,bits = net.split('/')
netmask = struct.unpack('L',socket.inet_aton(netaddr))[0] & ((2L<<int(bits)-1) - 1)
return ipaddr & netmask == netmask
I like to use netaddr for that:
from netaddr import CIDR, IP
if IP("192.168.0.1") in CIDR("192.168.0.0/24"):
print "Yay!"
As arno_v pointed out in the comments, new version of netaddr does it like this:
from netaddr import IPNetwork, IPAddress
if IPAddress("192.168.0.1") in IPNetwork("192.168.0.0/24"):
print "Yay!"
Using ipaddress (in the stdlib since 3.3, at PyPi for 2.6/2.7):
>>> import ipaddress
>>> ipaddress.ip_address('192.168.0.1') in ipaddress.ip_network('192.168.0.0/24')
True
If you want to evaluate a lot of IP addresses this way, you'll probably want to calculate the netmask upfront, like
n = ipaddress.ip_network('192.0.0.0/16')
netw = int(n.network_address)
mask = int(n.netmask)
Then, for each address, calculate the binary representation with one of
a = int(ipaddress.ip_address('192.0.43.10'))
a = struct.unpack('!I', socket.inet_pton(socket.AF_INET, '192.0.43.10'))[0]
a = struct.unpack('!I', socket.inet_aton('192.0.43.10'))[0] # IPv4 only
Finally, you can simply check:
in_network = (a & mask) == netw
This code is working for me on Linux x86. I haven't really given any thought to endianess issues, but I have tested it against the "ipaddr" module using over 200K IP addresses tested against 8 different network strings, and the results of ipaddr are the same as this code.
def addressInNetwork(ip, net):
import socket,struct
ipaddr = int(''.join([ '%02x' % int(x) for x in ip.split('.') ]), 16)
netstr, bits = net.split('/')
netaddr = int(''.join([ '%02x' % int(x) for x in netstr.split('.') ]), 16)
mask = (0xffffffff << (32 - int(bits))) & 0xffffffff
return (ipaddr & mask) == (netaddr & mask)
Example:
>>> print addressInNetwork('10.9.8.7', '10.9.1.0/16')
True
>>> print addressInNetwork('10.9.8.7', '10.9.1.0/24')
False
For python3
In [64]: ipaddress.IPv4Address('192.168.1.1') in ipaddress.IPv4Network('192.168.0.0/24')
Out[64]: False
I tried Dave Webb's solution but hit some problems:
Most fundamentally - a match should be checked by ANDing the IP address with the mask, then checking the result matched the Network address exactly. Not ANDing the IP address with the Network address as was done.
I also noticed that just ignoring the Endian behaviour assuming that consistency will save you will only work for masks on octet boundaries (/24, /16). In order to get other masks (/23, /21) working correctly I added a "greater than" to the struct commands and changed the code for creating the binary mask to start with all "1" and shift left by (32-mask).
Finally, I added a simple check that the network address is valid for the mask and just print a warning if it is not.
Here's the result:
def addressInNetwork(ip,net):
"Is an address in a network"
ipaddr = struct.unpack('>L',socket.inet_aton(ip))[0]
netaddr,bits = net.split('/')
netmask = struct.unpack('>L',socket.inet_aton(netaddr))[0]
ipaddr_masked = ipaddr & (4294967295<<(32-int(bits))) # Logical AND of IP address and mask will equal the network address if it matches
if netmask == netmask & (4294967295<<(32-int(bits))): # Validate network address is valid for mask
return ipaddr_masked == netmask
else:
print "***WARNING*** Network",netaddr,"not valid with mask /"+bits
return ipaddr_masked == netmask
I'm not a fan of using modules when they are not needed. This job only requires simple math, so here is my simple function to do the job:
def ipToInt(ip):
o = map(int, ip.split('.'))
res = (16777216 * o[0]) + (65536 * o[1]) + (256 * o[2]) + o[3]
return res
def isIpInSubnet(ip, ipNetwork, maskLength):
ipInt = ipToInt(ip)#my test ip, in int form
maskLengthFromRight = 32 - maskLength
ipNetworkInt = ipToInt(ipNetwork) #convert the ip network into integer form
binString = "{0:b}".format(ipNetworkInt) #convert that into into binary (string format)
chopAmount = 0 #find out how much of that int I need to cut off
for i in range(maskLengthFromRight):
if i < len(binString):
chopAmount += int(binString[len(binString)-1-i]) * 2**i
minVal = ipNetworkInt-chopAmount
maxVal = minVal+2**maskLengthFromRight -1
return minVal <= ipInt and ipInt <= maxVal
Then to use it:
>>> print isIpInSubnet('66.151.97.0', '66.151.97.192',24)
True
>>> print isIpInSubnet('66.151.97.193', '66.151.97.192',29)
True
>>> print isIpInSubnet('66.151.96.0', '66.151.97.192',24)
False
>>> print isIpInSubnet('66.151.97.0', '66.151.97.192',29)
That's it, this is much faster than the solutions above with the included modules.
The accepted answer doesn't work ... which is making me angry. Mask is backwards and doesn't work with any bits that are not a simple 8 bit block (eg /24). I adapted the answer, and it works nicely.
import socket,struct
def addressInNetwork(ip, net_n_bits):
ipaddr = struct.unpack('!L', socket.inet_aton(ip))[0]
net, bits = net_n_bits.split('/')
netaddr = struct.unpack('!L', socket.inet_aton(net))[0]
netmask = (0xFFFFFFFF >> int(bits)) ^ 0xFFFFFFFF
return ipaddr & netmask == netaddr
here is a function that returns a dotted binary string to help visualize the masking.. kind of like ipcalc output.
def bb(i):
def s = '{:032b}'.format(i)
def return s[0:8]+"."+s[8:16]+"."+s[16:24]+"."+s[24:32]
eg:
Not in the Standard library for 2.5, but ipaddr makes this very easy. I believe it is in 3.3 under the name ipaddress.
import ipaddr
a = ipaddr.IPAddress('192.168.0.1')
n = ipaddr.IPNetwork('192.168.0.0/24')
#This will return True
n.Contains(a)
Marc's code is nearly correct. A complete version of the code is -
def addressInNetwork3(ip,net):
'''This function allows you to check if on IP belogs to a Network'''
ipaddr = struct.unpack('=L',socket.inet_aton(ip))[0]
netaddr,bits = net.split('/')
netmask = struct.unpack('=L',socket.inet_aton(calcDottedNetmask(int(bits))))[0]
network = struct.unpack('=L',socket.inet_aton(netaddr))[0] & netmask
return (ipaddr & netmask) == (network & netmask)
def calcDottedNetmask(mask):
bits = 0
for i in xrange(32-mask,32):
bits |= (1 << i)
return "%d.%d.%d.%d" % ((bits & 0xff000000) >> 24, (bits & 0xff0000) >> 16, (bits & 0xff00) >> 8 , (bits & 0xff))
Obviously from the same sources as above...
A very Important note is that the first code has a small glitch - The IP address 255.255.255.255 also shows up as a Valid IP for any subnet. I had a heck of time getting this code to work and thanks to Marc for the correct answer.
Relying on the "struct" module can cause problems with endian-ness and type sizes, and just isn't needed. Nor is socket.inet_aton(). Python works very well with dotted-quad IP addresses:
def ip_to_u32(ip):
return int(''.join('%02x' % int(d) for d in ip.split('.')), 16)
I need to do IP matching on each socket accept() call, against a whole set of allowable source networks, so I precompute masks and networks, as integers:
SNS_SOURCES = [
# US-EAST-1
'207.171.167.101',
'207.171.167.25',
'207.171.167.26',
'207.171.172.6',
'54.239.98.0/24',
'54.240.217.16/29',
'54.240.217.8/29',
'54.240.217.64/28',
'54.240.217.80/29',
'72.21.196.64/29',
'72.21.198.64/29',
'72.21.198.72',
'72.21.217.0/24',
]
def build_masks():
masks = [ ]
for cidr in SNS_SOURCES:
if '/' in cidr:
netstr, bits = cidr.split('/')
mask = (0xffffffff << (32 - int(bits))) & 0xffffffff
net = ip_to_u32(netstr) & mask
else:
mask = 0xffffffff
net = ip_to_u32(cidr)
masks.append((mask, net))
return masks
Then I can quickly see if a given IP is within one of those networks:
ip = ip_to_u32(ipstr)
for mask, net in cached_masks:
if ip & mask == net:
# matched!
break
else:
raise BadClientIP(ipstr)
No module imports needed, and the code is very fast at matching.
from netaddr import all_matching_cidrs
>>> from netaddr import all_matching_cidrs
>>> all_matching_cidrs("212.11.70.34", ["192.168.0.0/24","212.11.64.0/19"] )
[IPNetwork('212.11.64.0/19')]
Here is the usage for this method:
>>> help(all_matching_cidrs)
Help on function all_matching_cidrs in module netaddr.ip:
all_matching_cidrs(ip, cidrs)
Matches an IP address or subnet against a given sequence of IP addresses and subnets.
@param ip: a single IP address or subnet.
@param cidrs: a sequence of IP addresses and/or subnets.
@return: all matching IPAddress and/or IPNetwork objects from the provided
sequence, an empty list if there was no match.
Basically you provide an ip address as the first argument and a list of cidrs as the second argument. A list of hits are returned.
#This works properly without the weird byte by byte handling
def addressInNetwork(ip,net):
'''Is an address in a network'''
# Convert addresses to host order, so shifts actually make sense
ip = struct.unpack('>L',socket.inet_aton(ip))[0]
netaddr,bits = net.split('/')
netaddr = struct.unpack('>L',socket.inet_aton(netaddr))[0]
# Must shift left an all ones value, /32 = zero shift, /0 = 32 shift left
netmask = (0xffffffff << (32-int(bits))) & 0xffffffff
# There's no need to mask the network address, as long as its a proper network address
return (ip & netmask) == netaddr
The choosen answer has a bug.
Following is the correct code:
def addressInNetwork(ip, net_n_bits):
ipaddr = struct.unpack('<L', socket.inet_aton(ip))[0]
net, bits = net_n_bits.split('/')
netaddr = struct.unpack('<L', socket.inet_aton(net))[0]
netmask = ((1L << int(bits)) - 1)
return ipaddr & netmask == netaddr & netmask
Note: ipaddr & netmask == netaddr & netmask instead of ipaddr & netmask == netmask.
I also replace ((2L<<int(bits)-1) - 1) with ((1L << int(bits)) - 1), as the latter seems more understandable.
Here is a class I wrote for longest prefix matching:
#!/usr/bin/env python
class Node:
def __init__(self):
self.left_child = None
self.right_child = None
self.data = "-"
def setData(self, data): self.data = data
def setLeft(self, pointer): self.left_child = pointer
def setRight(self, pointer): self.right_child = pointer
def getData(self): return self.data
def getLeft(self): return self.left_child
def getRight(self): return self.right_child
def __str__(self):
return "LC: %s RC: %s data: %s" % (self.left_child, self.right_child, self.data)
class LPMTrie:
def __init__(self):
self.nodes = [Node()]
self.curr_node_ind = 0
def addPrefix(self, prefix):
self.curr_node_ind = 0
prefix_bits = ''.join([bin(int(x)+256)[3:] for x in prefix.split('/')[0].split('.')])
prefix_length = int(prefix.split('/')[1])
for i in xrange(0, prefix_length):
if (prefix_bits[i] == '1'):
if (self.nodes[self.curr_node_ind].getRight()):
self.curr_node_ind = self.nodes[self.curr_node_ind].getRight()
else:
tmp = Node()
self.nodes[self.curr_node_ind].setRight(len(self.nodes))
tmp.setData(self.nodes[self.curr_node_ind].getData());
self.curr_node_ind = len(self.nodes)
self.nodes.append(tmp)
else:
if (self.nodes[self.curr_node_ind].getLeft()):
self.curr_node_ind = self.nodes[self.curr_node_ind].getLeft()
else:
tmp = Node()
self.nodes[self.curr_node_ind].setLeft(len(self.nodes))
tmp.setData(self.nodes[self.curr_node_ind].getData());
self.curr_node_ind = len(self.nodes)
self.nodes.append(tmp)
if i == prefix_length - 1 :
self.nodes[self.curr_node_ind].setData(prefix)
def searchPrefix(self, ip):
self.curr_node_ind = 0
ip_bits = ''.join([bin(int(x)+256)[3:] for x in ip.split('.')])
for i in xrange(0, 32):
if (ip_bits[i] == '1'):
if (self.nodes[self.curr_node_ind].getRight()):
self.curr_node_ind = self.nodes[self.curr_node_ind].getRight()
else:
return self.nodes[self.curr_node_ind].getData()
else:
if (self.nodes[self.curr_node_ind].getLeft()):
self.curr_node_ind = self.nodes[self.curr_node_ind].getLeft()
else:
return self.nodes[self.curr_node_ind].getData()
return None
def triePrint(self):
n = 1
for i in self.nodes:
print n, ':'
print i
n += 1
And here is a test program:
n=LPMTrie()
n.addPrefix('10.25.63.0/24')
n.addPrefix('10.25.63.0/16')
n.addPrefix('100.25.63.2/8')
n.addPrefix('100.25.0.3/16')
print n.searchPrefix('10.25.63.152')
print n.searchPrefix('100.25.63.200')
#10.25.63.0/24
#100.25.0.3/16
Thank you for your script!
I have work quite a long on it to make everything working... So I'm sharing it here
- Using netaddr Class is 10 times slower than using binary conversion, so if you'd like to use it on a big list of IP, you should consider not using netaddr class
makeMask function is not working! Only working for /8,/16,/24
Ex:bits = "21" ; socket.inet_ntoa(struct.pack('=L',(2L << int(bits)-1) - 1))
'255.255.31.0' whereas it should be 255.255.248.0So I have used another function calcDottedNetmask(mask) from http://code.activestate.com/recipes/576483-convert-subnetmask-from-cidr-notation-to-dotdecima/
Ex:
#!/usr/bin/python
>>> calcDottedNetmask(21)
>>> '255.255.248.0'
- Another problem is the process of matching if an IP belongs to a network! Basic Operation should be to compare (ipaddr & netmask) and (network & netmask).
Ex: for the time being, the function is wrong
#!/usr/bin/python
>>> addressInNetwork('188.104.8.64','172.16.0.0/12')
>>>True which is completely WRONG!!
So my new addressInNetwork function looks-like:
#!/usr/bin/python
import socket,struct
def addressInNetwork(ip,net):
'''This function allows you to check if on IP belogs to a Network'''
ipaddr = struct.unpack('=L',socket.inet_aton(ip))[0]
netaddr,bits = net.split('/')
netmask = struct.unpack('=L',socket.inet_aton(calcDottedNetmask(bits)))[0]
network = struct.unpack('=L',socket.inet_aton(netaddr))[0] & netmask
return (ipaddr & netmask) == (network & netmask)
def calcDottedNetmask(mask):
bits = 0
for i in xrange(32-int(mask),32):
bits |= (1 > 24, (bits & 0xff0000) >> 16, (bits & 0xff00) >> 8 , (bits & 0xff))
And now, answer is right!!
#!/usr/bin/python
>>> addressInNetwork('188.104.8.64','172.16.0.0/12')
False
I hope that it will help other people, saving time for them!
Relating to all of the above, I think socket.inet_aton() returns bytes in network order, so the correct way to unpack them is probably
struct.unpack('!L', ... )
previous solution have a bug in ip & net == net. Correct ip lookup is ip & netmask = net
bugfixed code:
import socket
import struct
def makeMask(n):
"return a mask of n bits as a long integer"
return (2L<<n-1) - 1
def dottedQuadToNum(ip):
"convert decimal dotted quad string to long integer"
return struct.unpack('L',socket.inet_aton(ip))[0]
def addressInNetwork(ip,net,netmask):
"Is an address in a network"
print "IP "+str(ip) + " NET "+str(net) + " MASK "+str(netmask)+" AND "+str(ip & netmask)
return ip & netmask == net
def humannetcheck(ip,net):
address=dottedQuadToNum(ip)
netaddr=dottedQuadToNum(net.split("/")[0])
netmask=makeMask(long(net.split("/")[1]))
return addressInNetwork(address,netaddr,netmask)
print humannetcheck("192.168.0.1","192.168.0.0/24");
print humannetcheck("192.169.0.1","192.168.0.0/24");
There is an API that's called SubnetTree available in python that do this job very well. This is a simple example :
import SubnetTree
t = SubnetTree.SubnetTree()
t.insert("10.0.1.3/32")
print("10.0.1.3" in t)
import socket,struct
def addressInNetwork(ip,net):
"Is an address in a network"
ipaddr = struct.unpack('!L',socket.inet_aton(ip))[0]
netaddr,bits = net.split('/')
netaddr = struct.unpack('!L',socket.inet_aton(netaddr))[0]
netmask = ((1<<(32-int(bits))) - 1)^0xffffffff
return ipaddr & netmask == netaddr & netmask
print addressInNetwork('10.10.10.110','10.10.10.128/25')
print addressInNetwork('10.10.10.110','10.10.10.0/25')
print addressInNetwork('10.10.10.110','10.20.10.128/25')
$ python check-subnet.py
False
True
False
I don't know of anything in the standard library, but PySubnetTree is a Python library that will do subnet matching.
From various sources above, and from my own research, this is how I got subnet and address calculation working. These pieces are enough to solve the question and other related questions.
class iptools:
@staticmethod
def dottedQuadToNum(ip):
"convert decimal dotted quad string to long integer"
return struct.unpack('>L', socket.inet_aton(ip))[0]
@staticmethod
def numToDottedQuad(n):
"convert long int to dotted quad string"
return socket.inet_ntoa(struct.pack('>L', n))
@staticmethod
def makeNetmask(mask):
bits = 0
for i in xrange(32-int(mask), 32):
bits |= (1 << i)
return bits
@staticmethod
def ipToNetAndHost(ip, maskbits):
"returns tuple (network, host) dotted-quad addresses given"
" IP and mask size"
# (by Greg Jorgensen)
n = iptools.dottedQuadToNum(ip)
m = iptools.makeMask(maskbits)
net = n & m
host = n - mask
return iptools.numToDottedQuad(net), iptools.numToDottedQuad(host)
Here is my code
# -*- coding: utf-8 -*-
import socket
class SubnetTest(object):
def __init__(self, network):
self.network, self.netmask = network.split('/')
self._network_int = int(socket.inet_aton(self.network).encode('hex'), 16)
self._mask = ((1L << int(self.netmask)) - 1) << (32 - int(self.netmask))
self._net_prefix = self._network_int & self._mask
def match(self, ip):
'''
判断传入的 IP 是不是本 Network 内的 IP
'''
ip_int = int(socket.inet_aton(ip).encode('hex'), 16)
return (ip_int & self._mask) == self._net_prefix
st = SubnetTest('100.98.21.0/24')
print st.match('100.98.23.32')
If you do not want to import other modules you could go with:
def ip_matches_network(self, network, ip):
"""
'{:08b}'.format(254): Converts 254 in a string of its binary representation
ip_bits[:net_mask] == net_ip_bits[:net_mask]: compare the ip bit streams
:param network: string like '192.168.33.0/24'
:param ip: string like '192.168.33.1'
:return: if ip matches network
"""
net_ip, net_mask = network.split('/')
net_mask = int(net_mask)
ip_bits = ''.join('{:08b}'.format(int(x)) for x in ip.split('.'))
net_ip_bits = ''.join('{:08b}'.format(int(x)) for x in net_ip.split('.'))
# example: net_mask=24 -> compare strings at position 0 to 23
return ip_bits[:net_mask] == net_ip_bits[:net_mask]
I tried one subset of proposed solutions in these answers.. with no success, I finally adapted and fixed the proposed code and wrote my fixed function.
I tested it and works at least on little endian architectures--e.g.x86-- if anyone likes to try on a big endian architecture, please give me feedback.
IP2Int code comes from this post, the other method is a fully (for my test cases) working fix of previous proposals in this question.
The code:
def IP2Int(ip):
o = map(int, ip.split('.'))
res = (16777216 * o[0]) + (65536 * o[1]) + (256 * o[2]) + o[3]
return res
def addressInNetwork(ip, net_n_bits):
ipaddr = IP2Int(ip)
net, bits = net_n_bits.split('/')
netaddr = IP2Int(net)
bits_num = int(bits)
netmask = ((1L << bits_num) - 1) << (32 - bits_num)
return ipaddr & netmask == netaddr & netmask
Hope useful,
来源：https://stackoverflow.com/questions/819355/how-can-i-check-if-an-ip-is-in-a-network-in-python