source: genesis/nodes/getrange.py@ 8594

#!/usr/bin/env python
# zoek de eerste vrije (== niet in een wleiden.conf gedefinieerde) interlink
# range
# lodewijk@wirelessleiden.nl
import re
import sys
import glob

def parseaddr(s):
        f = s.split('.')
        return (long(f[0]) << 24L) + \
                (long(f[1]) << 16L) + \
                (long(f[2]) << 8L) + \
                long(f[3])

def showaddr(a):
        return "%d.%d.%d.%d" % ((a >> 24) & 0xff, (a >> 16) & 0xff, (a >> 8) & 0xff, a & 0xff)

def get_ranges(interlink, size, aantal):
        numaddrs = 1 << (32 - size)
        
        substre = re.compile("^(\$[a-zA-Z][^ =]*) ?= ?'([^']*)';")
        
        
        bezet = {}
        
        for fname in glob.glob("*/wleiden.conf"):
                substs = {}
                lineNr = 0
                for l in open(fname):
                        lineNr += 1
                        l = l[:-1]
                        match = substre.match(l)
                        if match != None:
                                substs[match.group(1)] = match.group(2)
                        if l.startswith("IP="):
                                right = l[3:]
                                if '/' not in right:
                                        addr = right
                                        mask = 32
                                else:
                                        addr, mask = right.split('/')
                                        if addr in substs:
                                                addr = substs[addr]
                                try:
                                        addr = parseaddr(addr)
                                        mask = int(mask)
                                        addr = addr & ~((1 << (32 - mask)) - 1)
                                        for i in range(0, (1 << (32 - mask))):
                                                bezet[addr + i] = 1
                                except ValueError, e:
                                        print "[FOUT] in bestand '%s' regel '%i': %s" % (fname, lineNr, l)

        # Fetching smallest in use IP 
        # XXX: Currently not used for anything
        i = parseaddr("255.255.255.255")
        for k in bezet.keys():
                if k < i:
                        i = k
        
        # Interlinks are living in special ranges usually
        if interlink:
                i = parseaddr("172.16.3.0")
        else:
                i = parseaddr("172.17.0.0")
        
        ranges = []
        for n in xrange(aantal):
                okay = False
                while not okay: 
                        while bezet.has_key(i):
                                i = i + numaddrs
                        
                        # Assume Ok, till we find a already used IP
                        okay = True
                        for j in range(numaddrs):
                                if bezet.has_key(i + j):
                                        i = i + numaddrs
                                        okay = False
                                        break
                ranges.append(i)
                bezet[i] = 1

        return ranges

def main():
        if len(sys.argv) < 2:
                print "Gebruik: %s <interlink|subnet> <grootte> [aantal]" % sys.argv[0]
                print "Voorbeelden:"
                print "\tVoor drie /29 interlinks - '%s interlink 29 3'" % sys.argv[0]
                print "\tVoor een (1) /24 subnet  - '%s subnet 24'" % sys.argv[0]
                exit(1)
        
        # Argument parsing
        interlink = sys.argv[1] == 'interlink'
        size = int(sys.argv[2])
        try:
                aantal = int(sys.argv[3])
        except (KeyError,IndexError):
            aantal = 1
        
        ranges = get_ranges(interlink, size, aantal)
        numaddrs = 1 << (32 - size)

        for i in ranges:
                print "%s/%d:" % (showaddr(i), size),
                if size > 28:
                        print " en ".join([showaddr(i) for i in range(i + 1, i + numaddrs - 1)])
                else:
                        print " en ".join([showaddr(i) for i in range(i + 1, i + 4)]),
                        print "...",
                        print " en ".join([showaddr(i) for i in range(i + numaddrs - 7, i + numaddrs - 4)])

if __name__ == "__main__":
    main()