diff options
Diffstat (limited to 'third_party/dnspython/dns/reversename.py')
-rw-r--r-- | third_party/dnspython/dns/reversename.py | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/third_party/dnspython/dns/reversename.py b/third_party/dnspython/dns/reversename.py new file mode 100644 index 00000000000..4925cfd6ffd --- /dev/null +++ b/third_party/dnspython/dns/reversename.py @@ -0,0 +1,75 @@ +# 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: + parts = list(dns.ipv6.inet_aton(text).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') |