diff options
| -rw-r--r-- | rpkid/rpki/resource_set.py | 59 |
1 files changed, 53 insertions, 6 deletions
diff --git a/rpkid/rpki/resource_set.py b/rpkid/rpki/resource_set.py index f435c9fb..9b708543 100644 --- a/rpkid/rpki/resource_set.py +++ b/rpkid/rpki/resource_set.py @@ -117,6 +117,15 @@ class resource_range_ip(resource_range): raise rpki.exceptions.MustBePrefix, "%s cannot be expressed as a prefix" % str(self) return _long2bs(self.min, self.datum_type.bits, prefixlen = prefixlen) + @classmethod + def make_prefix(cls, address, prefixlen): + """Construct a resource range corresponding to a prefix.""" + assert isinstance(address, cls.datum_type) and isinstance(prefixlen, (int, long)) + assert prefixlen >= 0 and prefixlen <= cls.datum_type.bits, "Nonsensical prefix length: %s" % prefixlen + mask = (1 << (cls.datum_type.bits - prefixlen)) - 1 + assert (address & mask) == 0, "Resource not in canonical form: %s/s" % (address, prefixlen) + return cls(cls.datum_type(address), cls.datum_type(address | mask)) + class resource_range_ipv4(resource_range_ip): """Range of IPv4 addresses.""" @@ -336,12 +345,7 @@ class resource_set_ip(resource_set): return self.range_type(self.range_type.datum_type(r.group(1)), self.range_type.datum_type(r.group(2))) r = re.match("^([0-9:.a-fA-F]+)/([0-9]+)$", x) if r: - min = self.range_type.datum_type(r.group(1)) - prefixlen = int(r.group(2)) - mask = (1 << (self.range_type.datum_type.bits - prefixlen)) - 1 - assert (min & mask) == 0, "Resource not in canonical form: %s" % (x) - max = self.range_type.datum_type(min | mask) - return self.range_type(min, max) + return self.range_type.make_prefix(self.range_type.datum_type(r.group(1)), int(r.group(2))) raise RuntimeError, 'Bad IP resource "%s"' % (x) def parse_rfc3779_tuple(self, x): @@ -503,6 +507,49 @@ class resource_bag(object): s += "V6: %s" % self.v6 return s +# Sadly, there are enough differences between RFC 3779 and the data +# structures in the latest proposed ROA format that we can't just use +# the RFC 3779 code for ROAs. So we need a separate set of classes +# that are similar in concept but different in detail, with conversion +# functions. Such is life. I suppose it might be possible to do this +# with multiple inheritance, but that's probably more bother than it's +# worth. + +class roa_prefix(object): + """ROA prefix. This is similar to the resource_range_ip class, but + differs in that it only represents prefixes, never ranges, and + includes the maximum prefix length as an additional value. + """ + + def __init__(self, address, prefixlen, max_prefixlen = None): + """Initialize a ROA prefix. max_prefixlen is optional and + defaults to prefixlen. max_prefixlen must not be smaller than + prefixlen. + """ + if max_prefixlen is None: + max_prefixlen = prefixlen + assert max_prefixlen >= prefixlen, "Bad max_prefixlen: %d must not be shorter than %d" % (max_prefixlen, prefixlen) + self.address = address + self.prefixlen = prefixlen + self.max_prefixlen = max_prefixlen + + def __cmp__(self, other): + """Compare two ROA prefix objects. Comparision is based on + address, prefixlen, and max_prefixlen, in that order. + """ + c = self.address - other.address + if c == 0: c = self.prefixlen - other.prefixlen + if c == 0: c = self.max_prefixlen - other.max_prefixlen + if c < 0: c = -1 + if c > 0: c = 1 + return c + + def __str__(self): + """Convert a ROA prefix to string format.""" + return str(self.address) + "/" + str(self.prefixlen) + "-" + str(self.max_prefixlen) + + # CONTINUE HERE + # Test suite for set operations. This will probably go away eventually if __name__ == "__main__": |