Initial commit

Author: chamilton-ccn

README.md

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+# `python-hexroute`
+
+
+## Summary
+
+This is a python version of the original bash `hexroute` script (availble [here](http://www.xrx.ca/hexroute.htm)).
+
+
+## Installation
+
+Just download and run the script:
+
+    wget https://raw.githubusercontent.com/musashiXXX/python-hexroute/main/hexroute.py
+    chmod 755 hexroute.py
+    ./hexroute.py
+
+
+Or install it via `pipenv` to be used as a module:
+
+    pipenv install -e git+https://github.com/musashiXXX/python-hexroute.git#egg=python-hexroute
+
+
+## Usage
+
+    usage: hexroute.py [-h] (-r 192.168.0.0/16 192.168.0.1 | -R 18:C0:A8:64:C0:A8:64:01)
+
+    Generate or parse a DHCP option 249 hexadecimal string
+
+    optional arguments:
+      -h, --help            show this help message and exit
+      -r 192.168.0.0/16 192.168.0.1, --route 192.168.0.0/16 192.168.0.1
+                            Specify a network/gateway pair
+      -R 18:C0:A8:64:C0:A8:64:01, --reverse 18:C0:A8:64:C0:A8:64:01
+                            Convert an option 121/249 hex string into IPv4 network/route pairs
+
+
+Generate a hex string:
+
+    ./hexroute.py -r 10.10.10.0/24 192.168.0.1 -r 172.16.0.0/12 192.168.0.1
+    18:0A:0A:0A:C0:A8:00:01:0C:AC:10:C0:A8:00:01
+
+
+Parse a hex string:
+
+    ./hexroute.py -R '18:0A:0A:0A:C0:A8:00:01:0C:AC:10:C0:A8:00:01'
+    [(IPv4Network('10.10.10.0/24'), IPv4Address('192.168.0.1')), (IPv4Network('172.16.0.0/12'), IPv4Address('192.168.0.1'))]
+

hexroute.py

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+#!/usr/bin/env python
+
+import ipaddress, argparse, itertools
+
+def hexroute(routes: list, uppercase=True) -> str:
+    '''
+       Takes a list of lists or tuples in the form ('network/prefix', 'gateway_ip')
+       and returns a DHCP option 121/249 hex string
+
+       >>> hexroute([('192.168.100.0/24','192.168.100.1')])
+       '18:C0:A8:64:C0:A8:64:01'
+       >>> hexroute([('172.16.0.0/24', '172.16.0.1')])
+       '18:AC:10:00:AC:10:00:01'
+       >>> hexroute([('10.1.1.10/8', '10.254.254.1')])
+       '08:0A:0A:FE:FE:01'
+       >>> hexroute([('192.168.1.0/23','192.168.0.1'), ('192.168.0.0/23', '192.168.0.1')])
+       '17:C0:A8:00:C0:A8:00:01'
+    '''
+
+    hex = []
+    networks = []
+    for route in routes:
+        net = ipaddress.IPv4Network(route[0], strict=False)
+        if net in networks:
+            continue
+        prefix = net.prefixlen
+        net_address = [int(i) for i in str(net.network_address).split('.')]
+        gateway_address = [int(i) for i in str(route[1]).split('.')]
+        octets = []
+        if prefix > 0:
+            octets.append(net_address[0])
+        if prefix > 8:
+            octets.append(net_address[1])
+        if prefix > 16:
+            octets.append(net_address[2])
+        if prefix > 24:
+            octets.append(net_address[3])
+        container = [prefix]
+        container += octets
+        container += gateway_address
+        hex += ['{:02X}'.format(i) for i in container]
+        networks.append(net)
+    
+    opt249str = ':'.join(hex)
+    if not uppercase:
+        return opt249str.lower()
+    return opt249str
+
+def hexroute_reverse(hex_string):
+    '''
+       Takes a hexadecimal DHCP option 249 string and returns the IPv4 networks and their gateways
+
+       >>> hexroute_reverse('18:C0:A8:64:C0:A8:64:01')
+       [(IPv4Network('192.168.100.0/24'), IPv4Address('192.168.100.1'))]
+       >>> hexroute_reverse('18:AC:10:00:AC:10:00:01')
+       [(IPv4Network('172.16.0.0/24'), IPv4Address('172.16.0.1'))]
+       >>> hexroute_reverse('08:0A:0A:FE:FE:01')
+       [(IPv4Network('10.0.0.0/8'), IPv4Address('10.254.254.1'))]
+       >>> hexroute_reverse('17:C0:A8:00:C0:A8:00:01')
+       [(IPv4Network('192.168.0.0/23'), IPv4Address('192.168.0.1'))]
+    '''
+
+    decimal_vals = [int(i, 16) for i in hex_string.split(':')]
+    routes = []
+    while len(decimal_vals):
+        next = 0
+        subnet = decimal_vals.pop(0)
+        for i in (0, 8, 16, 24):
+                if subnet > i:
+                        next += 1
+        subnet_octets = decimal_vals[:next]
+        while len(subnet_octets) < 4:
+                subnet_octets.append(0)
+        network = ipaddress.IPv4Network('.'.join([str(i) for i in subnet_octets]) + '/{}'.format(subnet), strict=False)
+        del decimal_vals[:next]
+        gateway_address = decimal_vals[:4]
+        gateway = ipaddress.IPv4Address('.'.join([str(i) for i in gateway_address]))
+        del decimal_vals[:4]
+        routes.append((network, gateway))
+    return routes
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description = 'Generate or parse a DHCP option 249 hexadecimal string')
+    group = parser.add_mutually_exclusive_group(required=True)
+    group.add_argument(
+        '-r',
+        '--route',
+        help='Specify a network/gateway pair',
+        metavar=('192.168.0.0/16', '192.168.0.1'),
+        nargs=2,
+        action='append'
+    )
+    group.add_argument(
+        '-R',
+        '--reverse',
+        help='Convert an option 121/249 hex string into IPv4 network/route pairs',
+        metavar='18:C0:A8:64:C0:A8:64:01'
+    )
+    args = parser.parse_args()
+    if args.route:
+        print(hexroute(args.route))
+    if args.reverse:
+        print(hexroute_reverse(args.reverse))

pyproject.toml

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+[project]
+name = "python-hexroute"
+version = "0.1"
+
+readme = "README.md"
+keywords = ["dhcp", "249", "121"]
+requires-python = ">3.7"

setup.py

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+#!/usr/bin/env python
+# -*- coding: utf8 -*-
+
+import sys 
+
+try:
+    from setuptools import setup
+except ImportError:
+    from distutils.core import setup
+
+setup( 
+  name='hexroute',
+  version='0.1',
+  url='https://github.com/musashiXXX/python-hexroute',
+  license='GNU GPLv3',
+  author='Charles Hamilton',
+  author_email='chamilton@nefaria.com',
+  keywords='249 121 dhcp hexroute',
+  description='Generate a hex string for use with DHCP options 121/249',
+  long_description='',
+  classifiers=['Programming Language :: Python :: 3'],
+  py_modules=['hexroute']
+)
+