# IP address manipulation functions, dressed up a bit
import socket, struct
def dottedQuadToNum(ip):
"convert decimal dotted quad string to long integer"
return struct.unpack('L',socket.inet_aton(ip))[0]
def numToDottedQuad(n):
"convert long int to dotted quad string"
return socket.inet_ntoa(struct.pack('L',n))
def makeMask(n):
"return a mask of n bits as a long integer"
return (2L<<n-1)-1
def ipToNetAndHost(ip, maskbits):
"returns tuple (network, host) dotted-quad addresses given IP and mask size"
# (by Greg Jorgensen)
n = dottedQuadToNum(ip)
m = makeMask(maskbits)
host = n & m
net = n - host
return numToDottedQuad(net), numToDottedQuad(host)
