class BTrie(object):
""" A class to construct and perform lookups on a btrie.
Since we do not have python bindings for btrie, we do this in a
roundabout way by running rbldnsd with a single ip6trie dataset,
and then querying the rbldnsd to perform the lookup.
"""
def __init__(self, prefixes, **kwargs):
self.rbldnsd = Rbldnsd(**kwargs)
zonedata = (self._zone_entry(*prefix) for prefix in prefixes)
self.rbldnsd.add_dataset('ip6trie', ZoneFile(zonedata))
def __enter__(self):
self.rbldnsd.__enter__()
return self
def __exit__(self, exc_type, exc_value, exc_tb):
return self.rbldnsd.__exit__(exc_type, exc_value, exc_tb)
def lookup(self, prefix, plen):
prefix = pad_prefix(prefix, plen)
nibbles = '.'.join("%x" % ((prefix >> n) & 0x0f)
for n in range(0, 128, 4))
return self.rbldnsd.query(nibbles + '.example.com')
def _zone_entry(self, prefix, plen, data):
prefix = pad_prefix(prefix, plen)
ip6addr = ':'.join("%x" % ((prefix >> n) & 0xffff)
for n in range(112, -16, -16))
return "%s/%u :1:%s" % (ip6addr, plen, data)
