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# Authors: Martin Basti <mbasti@redhat.com>
#
# Copyright (C) 2007-2014 Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import dns.name
import dns.exception
import copy
import six
if six.PY3:
unicode = str
@six.python_2_unicode_compatible
class DNSName(dns.name.Name):
labels = None # make pylint happy
@classmethod
def from_text(cls, labels, origin=None):
return cls(dns.name.from_text(labels, origin))
def __init__(self, labels, origin=None):
try:
if isinstance(labels, six.string_types):
#pylint: disable=E1101
labels = dns.name.from_text(unicode(labels), origin).labels
elif isinstance(labels, dns.name.Name):
labels = labels.labels
super(DNSName, self).__init__(labels)
except UnicodeError as e:
# dnspython bug, an invalid domain name returns the UnicodeError
# instead of a dns.exception
raise dns.exception.SyntaxError(e)
def __bool__(self):
#dns.name.from_text('@') is represented like empty tuple
#we need to acting '@' as nonzero value
return True
__nonzero__ = __bool__ # for Python 2
def __copy__(self):
return DNSName(self.labels)
def __deepcopy__(self, memo):
return DNSName(copy.deepcopy(self.labels, memo))
def __str__(self):
return self.to_unicode()
def ToASCII(self):
#method named by RFC 3490 and python standard library
return self.to_text().decode('ascii') # must be unicode string
def canonicalize(self):
return DNSName(super(DNSName, self).canonicalize())
def concatenate(self, other):
return DNSName(super(DNSName, self).concatenate(other))
def relativize(self, origin):
return DNSName(super(DNSName, self).relativize(origin))
def derelativize(self, origin):
return DNSName(super(DNSName, self).derelativize(origin))
def choose_relativity(self, origin=None, relativize=True):
return DNSName(super(DNSName, self).choose_relativity(origin=origin,
relativize=relativize))
def make_absolute(self):
return self.derelativize(self.root)
def is_idn(self):
return any(label.startswith('xn--') for label in self.labels)
def is_ip4_reverse(self):
return self.is_subdomain(self.ip4_rev_zone)
def is_ip6_reverse(self):
return self.is_subdomain(self.ip6_rev_zone)
def is_reverse(self):
return self.is_ip4_reverse() or self.is_ip6_reverse()
def is_empty(self):
return len(self.labels) == 0
#DNS public constants
DNSName.root = DNSName(dns.name.root) # '.'
DNSName.empty = DNSName(dns.name.empty) # '@'
DNSName.ip4_rev_zone = DNSName(('in-addr', 'arpa', ''))
DNSName.ip6_rev_zone = DNSName(('ip6', 'arpa', ''))
# Empty zones are defined in various RFCs. BIND is by default serving them.
# This constat should contain everything listed in
# IANA registry "Locally-Served DNS Zones"
# URL: http://www.iana.org/assignments/locally-served-dns-zones
# + AS112 zone defined in RFC 7534. It is not in the registry for some
# reason but BIND 9.10 is serving it as automatic empty zones.
EMPTY_ZONES = [DNSName(aez).make_absolute() for aez in [
# RFC 1918
"10.IN-ADDR.ARPA", "16.172.IN-ADDR.ARPA", "17.172.IN-ADDR.ARPA",
"18.172.IN-ADDR.ARPA", "19.172.IN-ADDR.ARPA", "20.172.IN-ADDR.ARPA",
"21.172.IN-ADDR.ARPA", "22.172.IN-ADDR.ARPA", "23.172.IN-ADDR.ARPA",
"24.172.IN-ADDR.ARPA", "25.172.IN-ADDR.ARPA", "26.172.IN-ADDR.ARPA",
"27.172.IN-ADDR.ARPA", "28.172.IN-ADDR.ARPA", "29.172.IN-ADDR.ARPA",
"30.172.IN-ADDR.ARPA", "31.172.IN-ADDR.ARPA", "168.192.IN-ADDR.ARPA",
# RFC 6598
"64.100.IN-ADDR.ARPA", "65.100.IN-ADDR.ARPA", "66.100.IN-ADDR.ARPA",
"67.100.IN-ADDR.ARPA", "68.100.IN-ADDR.ARPA", "69.100.IN-ADDR.ARPA",
"70.100.IN-ADDR.ARPA", "71.100.IN-ADDR.ARPA", "72.100.IN-ADDR.ARPA",
"73.100.IN-ADDR.ARPA", "74.100.IN-ADDR.ARPA", "75.100.IN-ADDR.ARPA",
"76.100.IN-ADDR.ARPA", "77.100.IN-ADDR.ARPA", "78.100.IN-ADDR.ARPA",
"79.100.IN-ADDR.ARPA", "80.100.IN-ADDR.ARPA", "81.100.IN-ADDR.ARPA",
"82.100.IN-ADDR.ARPA", "83.100.IN-ADDR.ARPA", "84.100.IN-ADDR.ARPA",
"85.100.IN-ADDR.ARPA", "86.100.IN-ADDR.ARPA", "87.100.IN-ADDR.ARPA",
"88.100.IN-ADDR.ARPA", "89.100.IN-ADDR.ARPA", "90.100.IN-ADDR.ARPA",
"91.100.IN-ADDR.ARPA", "92.100.IN-ADDR.ARPA", "93.100.IN-ADDR.ARPA",
"94.100.IN-ADDR.ARPA", "95.100.IN-ADDR.ARPA", "96.100.IN-ADDR.ARPA",
"97.100.IN-ADDR.ARPA", "98.100.IN-ADDR.ARPA", "99.100.IN-ADDR.ARPA",
"100.100.IN-ADDR.ARPA", "101.100.IN-ADDR.ARPA",
"102.100.IN-ADDR.ARPA", "103.100.IN-ADDR.ARPA",
"104.100.IN-ADDR.ARPA", "105.100.IN-ADDR.ARPA",
"106.100.IN-ADDR.ARPA", "107.100.IN-ADDR.ARPA",
"108.100.IN-ADDR.ARPA", "109.100.IN-ADDR.ARPA",
"110.100.IN-ADDR.ARPA", "111.100.IN-ADDR.ARPA",
"112.100.IN-ADDR.ARPA", "113.100.IN-ADDR.ARPA",
"114.100.IN-ADDR.ARPA", "115.100.IN-ADDR.ARPA",
"116.100.IN-ADDR.ARPA", "117.100.IN-ADDR.ARPA",
"118.100.IN-ADDR.ARPA", "119.100.IN-ADDR.ARPA",
"120.100.IN-ADDR.ARPA", "121.100.IN-ADDR.ARPA",
"122.100.IN-ADDR.ARPA", "123.100.IN-ADDR.ARPA",
"124.100.IN-ADDR.ARPA", "125.100.IN-ADDR.ARPA",
"126.100.IN-ADDR.ARPA", "127.100.IN-ADDR.ARPA",
# RFC 5735 and RFC 5737
"0.IN-ADDR.ARPA", "127.IN-ADDR.ARPA", "254.169.IN-ADDR.ARPA",
"2.0.192.IN-ADDR.ARPA", "100.51.198.IN-ADDR.ARPA",
"113.0.203.IN-ADDR.ARPA", "255.255.255.255.IN-ADDR.ARPA",
# Local IPv6 Unicast Addresses
"0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.ARPA",
"1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.ARPA",
# LOCALLY ASSIGNED LOCAL ADDRESS SCOPE
"D.F.IP6.ARPA", "8.E.F.IP6.ARPA", "9.E.F.IP6.ARPA", "A.E.F.IP6.ARPA",
"B.E.F.IP6.ARPA",
# Example Prefix, RFC 3849.
"8.B.D.0.1.0.0.2.IP6.ARPA",
# RFC 7534
"EMPTY.AS112.ARPA",
]]
def assert_absolute_dnsname(name):
"""Raise AssertionError if name is not DNSName or is not absolute.
>>> assert_absolute_dnsname(DNSName('absolute.name.example.'))
>>> assert_absolute_dnsname(DNSName('relative.name.example'))
Traceback (most recent call last):
...
AssertionError: name must be absolute, ...
>>> assert_absolute_dnsname('absolute.string.example.')
Traceback (most recent call last):
...
AssertionError: name must be DNSName instance, ...
"""
assert isinstance(name, DNSName), ("name must be DNSName instance, "
"got '%s'" % type(name))
assert name.is_absolute(), "name must be absolute, got '%s'" % name
def is_auto_empty_zone(zone):
"""True if specified zone name exactly matches an automatic empty zone.
>>> is_auto_empty_zone(DNSName('in-addr.arpa.'))
False
>>> is_auto_empty_zone(DNSName('10.in-addr.arpa.'))
True
>>> is_auto_empty_zone(DNSName('1.10.in-addr.arpa.'))
False
>>> is_auto_empty_zone(DNSName('10.in-addr.arpa'))
Traceback (most recent call last):
...
AssertionError: ...
"""
assert_absolute_dnsname(zone)
return zone in EMPTY_ZONES
def inside_auto_empty_zone(name):
"""True if specified absolute name is a subdomain of an automatic empty
zone.
DNS domain is a subdomain of itself so this function
returns True for zone apexes, too.
>>> inside_auto_empty_zone(DNSName('in-addr.arpa.'))
False
>>> inside_auto_empty_zone(DNSName('10.in-addr.arpa.'))
True
>>> inside_auto_empty_zone(DNSName('1.10.in-addr.arpa.'))
True
>>> inside_auto_empty_zone(DNSName('1.10.in-addr.arpa'))
Traceback (most recent call last):
...
AssertionError: ...
"""
assert_absolute_dnsname(name)
for aez in EMPTY_ZONES:
if name.is_subdomain(aez):
return True
return False
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