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| # 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") | |