| 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889 |
- # 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 binascii
- import sys
- 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):
- if sys.version_info >= (3,):
- parts = ['%d' % byte for byte in v6[12:]]
- else:
- parts = ['%d' % ord(byte) for byte in v6[12:]]
- origin = ipv4_reverse_domain
- else:
- parts = [x for x in str(binascii.hexlify(v6).decode())]
- origin = ipv6_reverse_domain
- except Exception:
- parts = ['%d' %
- byte for byte in bytearray(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 = b'.'.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(b''.join(labels[i:i + 4]))
- i += 4
- text = b':'.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')
|