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#!/usr/bin/env python2.1

# iputils.py
#
# Author: Grahame Bowland <grahame@ucs.uwa.edu.au>
# License: GNU GPL

import sys
import socket

class Network:
    def __init__(self, address, mask):
        self.address = address
        self.mask = mask
    def is_in(self, ip):
        # is "ip" within our network
        c1 = ip & self.mask
        c2 = self.address & self.mask
	# 130.95.0.0 & 255.255.255.0 = 130.95.0.0
	# 130.95.2.0 & 255.255.255.0 = 130.95.2.0
        if c1 == c2:
            if c1 == 0 and self.address <> ip:
                # /32 route and not equal host addresses
                return 0
            return 1
        else:
            return 0

def ip_to_int(str, invert = 0):
    quads = str.split(".")
    if len(quads) <> 4:
        print "Invalid ip:", str
        sys.exit(1)
    rv = 0
    m = long(1)
    for i in range(len(quads)):
        cval = int(quads[3-i])
        if invert:
            cval = cval ^ 255
        if cval > 255 or cval < 0:
            print "Invalid ip; contains section out of bounds at index %d : %s"\
                % (4-i, str)
        rv = rv + (m * cval)
        m = m * 256
    return rv

def int_to_length(ip_int):
	len = 0
	while ip_int > 0:
		if ip_int % 2: break
		ip_int /= 2
		len += 1
	return 32 - len

def network_from_ip(ip, mask):
   pip = ip_to_int(ip)
   pmask = ip_to_int(mask)
   return Network(pip, pmask)

if __name__ == "__main__":
    a = network_from_ip("130.95.2.0", "255.255.255.0")
    print a.is_in(ip_to_int("130.95.0.0"))