# Copyright (C) 2006, 2007, 2009-2011 Nominum, Inc. # # Permission to use, copy, modify, and distribute this software and its # documentation for any purpose with or without fee is hereby granted, # provided that the above copyright notice and this permission notice # appear in all copies. # # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """DNS Reverse Map Names. @var ipv4_reverse_domain: The DNS IPv4 reverse-map domain, in-addr.arpa. @type ipv4_reverse_domain: dns.name.Name object @var ipv6_reverse_domain: The DNS IPv6 reverse-map domain, ip6.arpa. @type ipv6_reverse_domain: dns.name.Name object """ import dns.name import dns.ipv6 import dns.ipv4 ipv4_reverse_domain = dns.name.from_text('in-addr.arpa.') ipv6_reverse_domain = dns.name.from_text('ip6.arpa.') def from_address(text): """Convert an IPv4 or IPv6 address in textual form into a Name object whose value is the reverse-map domain name of the address. @param text: an IPv4 or IPv6 address in textual form (e.g. '127.0.0.1', '::1') @type text: str @rtype: dns.name.Name object """ try: v6 = dns.ipv6.inet_aton(text) if dns.ipv6.is_mapped(v6): parts = ['%d' % ord(byte) for byte in v6[12:]] origin = ipv4_reverse_domain else: parts = list(v6.encode('hex_codec')) origin = ipv6_reverse_domain except: parts = ['%d' % ord(byte) for byte in dns.ipv4.inet_aton(text)] origin = ipv4_reverse_domain parts.reverse() return dns.name.from_text('.'.join(parts), origin=origin) def to_address(name): """Convert a reverse map domain name into textual address form. @param name: an IPv4 or IPv6 address in reverse-map form. @type name: dns.name.Name object @rtype: str """ if name.is_subdomain(ipv4_reverse_domain): name = name.relativize(ipv4_reverse_domain) labels = list(name.labels) labels.reverse() text = '.'.join(labels) # run through inet_aton() to check syntax and make pretty. return dns.ipv4.inet_ntoa(dns.ipv4.inet_aton(text)) elif name.is_subdomain(ipv6_reverse_domain): name = name.relativize(ipv6_reverse_domain) labels = list(name.labels) labels.reverse() parts = [] i = 0 l = len(labels) while i < l: parts.append(''.join(labels[i:i+4])) i += 4 text = ':'.join(parts) # run through inet_aton() to check syntax and make pretty. return dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(text)) else: raise dns.exception.SyntaxError('unknown reverse-map address family')