# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license # Copyright (C) 2006-2017 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.""" import binascii import dns.ipv4 import dns.ipv6 import dns.name ipv4_reverse_domain = dns.name.from_text("in-addr.arpa.") ipv6_reverse_domain = dns.name.from_text("ip6.arpa.") def from_address( text: str, v4_origin: dns.name.Name = ipv4_reverse_domain, v6_origin: dns.name.Name = ipv6_reverse_domain, ) -> dns.name.Name: """Convert an IPv4 or IPv6 address in textual form into a Name object whose value is the reverse-map domain name of the address. *text*, a ``str``, is an IPv4 or IPv6 address in textual form (e.g. '127.0.0.1', '::1') *v4_origin*, a ``dns.name.Name`` to append to the labels corresponding to the address if the address is an IPv4 address, instead of the default (in-addr.arpa.) *v6_origin*, a ``dns.name.Name`` to append to the labels corresponding to the address if the address is an IPv6 address, instead of the default (ip6.arpa.) Raises ``dns.exception.SyntaxError`` if the address is badly formed. Returns a ``dns.name.Name``. """ try: v6 = dns.ipv6.inet_aton(text) if dns.ipv6.is_mapped(v6): parts = ["%d" % byte for byte in v6[12:]] origin = v4_origin else: parts = [x for x in str(binascii.hexlify(v6).decode())] origin = v6_origin except Exception: parts = ["%d" % byte for byte in dns.ipv4.inet_aton(text)] origin = v4_origin return dns.name.from_text(".".join(reversed(parts)), origin=origin) def to_address( name: dns.name.Name, v4_origin: dns.name.Name = ipv4_reverse_domain, v6_origin: dns.name.Name = ipv6_reverse_domain, ) -> str: """Convert a reverse map domain name into textual address form. *name*, a ``dns.name.Name``, an IPv4 or IPv6 address in reverse-map name form. *v4_origin*, a ``dns.name.Name`` representing the top-level domain for IPv4 addresses, instead of the default (in-addr.arpa.) *v6_origin*, a ``dns.name.Name`` representing the top-level domain for IPv4 addresses, instead of the default (ip6.arpa.) Raises ``dns.exception.SyntaxError`` if the name does not have a reverse-map form. Returns a ``str``. """ if name.is_subdomain(v4_origin): name = name.relativize(v4_origin) text = b".".join(reversed(name.labels)) # run through inet_ntoa() to check syntax and make pretty. return dns.ipv4.inet_ntoa(dns.ipv4.inet_aton(text)) elif name.is_subdomain(v6_origin): name = name.relativize(v6_origin) labels = list(reversed(name.labels)) parts = [] for i in range(0, len(labels), 4): parts.append(b"".join(labels[i : i + 4])) text = b":".join(parts) # run through inet_ntoa() 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")