[Freeipa-devel] [PATCHES 0024, 0025] Classless support for reverse domains
Jan Cholasta
jcholast at redhat.com
Tue Feb 11 16:11:03 UTC 2014
On 11.2.2014 16:23, Martin Basti wrote:
> On Tue, 2014-02-11 at 15:42 +0100, Jan Cholasta wrote:
>> On 11.2.2014 14:29, Martin Basti wrote:
>>> On Mon, 2014-02-10 at 14:28 +0100, Jan Cholasta wrote:
>>>> On 10.2.2014 13:14, Martin Basti wrote:
>>>>> On Mon, 2014-02-10 at 12:22 +0100, Jan Cholasta wrote:
>>>>>> On 10.2.2014 08:50, Petr Spacek wrote:
>>>>>>> On 7.2.2014 10:42, Martin Basti wrote:
>>>>>>>> On Thu, 2014-02-06 at 17:04 +0100, Martin Basti wrote:
>>>>>>>>> On Thu, 2014-02-06 at 16:37 +0100, Jan Cholasta wrote:
>>>>>>>>>> On 6.2.2014 15:57, Martin Basti wrote:
>>>>>>>>>>> On Thu, 2014-02-06 at 10:59 +0100, Jan Cholasta wrote:
>>>>>>>>>>>> Hi,
>>>>>>>>>>>>
>>>>>>>>>>>> On 31.1.2014 16:06, Martin Basti wrote:
>>>>>>>>>>>>> Reverse domain names in form "0/28.0.10.10.in-addr.arpa." are now
>>>>>>>>>>>>> allowed.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Ticket: https://fedorahosted.org/freeipa/ticket/4143
>>>>>>>>>>>>> Patches attached.
>>>>>>>>>>>>
>>>>>>>>>>> I add Petr2 to CC, to inspect RFC issues, with allowing '/' in IPv6
>>>>>>>>>>>
>>>>>>>>>>>> I think the validation should be more strict. IPv4 reverse zones
>>>>>>>>>>>> should
>>>>>>>>>>>> allow slash only in the label for the last octet (i.e.
>>>>>>>>>>>> 0/25.1.168.192 is
>>>>>>>>>>>> valid, 0.1/25.168.192 is not). IPv6 reverse zones should not allow
>>>>>>>>>>>> slash
>>>>>>>>>>>> at all.
>>>>>>>>>>>>
>>>>>>>>>>> I havent found anything about IPv6, RFCs don't forbids it.
>>>>>>>>>>
>>>>>>>>>> AFAIK the RFCs do not forbid anything, but we do validation anyway, so
>>>>>>>>>> we might as well do it right, otherwise there is no point in doing it.
>>>>>>>>>>
>>>>>>>>> OK, I leave there only IPv4
>>>>>>
>>>>>> For the record, we discussed this off-line with Martin and Petr and
>>>>>> figured out it would be best to allow slashes in IPv6 reverse zones
>>>>>> after all.
>>>>>>
>>>>>>>>>
>>>>>>>>>>> 1.0/25.1.168.192.in-addr.arpa. is also valid, it could be used to
>>>>>>>>>>> CNAME
>>>>>>>>>>> records
>>>>>>>>>>
>>>>>>>>>> Yes, obviously. It's 1.0.1/25.168.192.in-addr.arpa. I'm concerned
>>>>>>>>>> about.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> http://tools.ietf.org/html/rfc6672#section-6.2
>>>>>>>>> This can give a very strange positions of / in FQDN
>>>>>>
>>>>>> Point taken.
>>>>>>
>>>>>>>>>
>>>>>>>>> Optionally, I could permit only 1 slash in domain name, but I have to
>>>>>>>>> inspect first if user can do something useful with subnet of subnet in
>>>>>>>>> DNS, like 1.0/25.128/25.168.192.in-addr.arpa
>>>>>>> Multiple slashes has to be allowed, without limitation to last octet.
>>>>>>> Imagine situation when split subnet is later split to even smaller pieces.
>>>>>>>
>>>>>>> Guys, do not over-engineer it. IMHO this validator should produce a
>>>>>>> warning is something is not as we expect but it should not block user
>>>>>>> from adding a record.
>>>>>>>
>>>>>>> We have had enough problems with too strict validators in the past and
>>>>>>> IMHO warning is the way to go.
>>>>>>
>>>>>> I agree, but it's too late to get such change into 3.3.x.
>>>>>>
>>>>>>>
>>>>>>> Petr^2 Spacek
>>>>>>>
>>>>>>>>>>> The slashes in domain names are referenced as the best practise in
>>>>>>>>>>> RFC,
>>>>>>>>>>> there are not strict rules.
>>>>>>>>>>>>
>>>>>>>>>>>> +def _cname_hostname_validator(ugettext, value):
>>>>>>>>>>>>
>>>>>>>>>>>> Can you name this _bind_cname_hostname_validator, so that it is
>>>>>>>>>>>> clear it
>>>>>>>>>>>> is related to _bind_hostname_validator?
>>>>>>>>>>>>
>>>>>>>>>>> I will rename it
>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> + #classless reverse zones can contain slash '/'
>>>>>>>>>>>> + if not zone_is_reverse(normalized_zone) and
>>>>>>>>>>>> (normalized_zone.count('/') > 0):
>>>>>>>>>>>> + raise errors.ValidationError(name='name',
>>>>>>>>>>>> + error=_("Only reverse zones can contain
>>>>>>>>>>>> '/' in
>>>>>>>>>>>> labels"))
>>>>>>>>>>>>
>>>>>>>>>>>> This should be handled in _domain_name_validator. Validation in
>>>>>>>>>>>> pre_callback should be done only when the validation depends on
>>>>>>>>>>>> values
>>>>>>>>>>>> of multiple parameters, which is not this case.
>>>>>>>>>>>>
>>>>>>>>>>> I will move it
>>>>>>>>>>>>
>>>>>>>>>>>> + def _reverse_zone_pre_callback(self, ldap, dn, entry_attrs,
>>>>>>>>>>>> *keys,
>>>>>>>>>>>> **options):
>>>>>>>>>>>>
>>>>>>>>>>>> Rename this to _idnsname_pre_callback and you won't have to call it
>>>>>>>>>>>> explicitly in run_precallback_validators.
>>>>>>>>>>>>
>>>>>>>>>>> I will rename it
>>>>>>>>>>>>
>>>>>>>>>>>> + if addr.count('/') > 0:
>>>>>>>>>>>>
>>>>>>>>>>>> I think "if '/' in addr:" would be better.
>>>>>>>>>>>>
>>>>>>>>>>> I will change it
>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> -def validate_dns_label(dns_label, allow_underscore=False):
>>>>>>>>>>>> +def validate_dns_label(dns_label, allow_underscore=False,
>>>>>>>>>>>> allow_slash=False):
>>>>>>>>>>>>
>>>>>>>>>>>> IMO instead of adding a new boolean argument, it would be nicer to
>>>>>>>>>>>> replace allow_underscore with an argument (e.g. allowed_chars) which
>>>>>>>>>>>> takes a string of extra allowed characters.
>>>>>>>>>>>>
>>>>>>>>>>> But I have to handle not only allowed chars, but position of the chars
>>>>>>>>>>> in the label string too.
>>>>>>>>>>
>>>>>>>>>> Why? Is there a RFC that forbids it?
>>>>>>>>>>
>>>>>>>>>> My point is, adding a new argument for each extra character is bad,
>>>>>>>>>> there should be a better way of doing that.
>>>>>>>>>>
>>>>>>>>> I agree, but for example: "_" should be at start (it is not required be
>>>>>>>>> at the start in IPA), "/" and "-" in the middle.
>>>>>>
>>>>>> OK then. (But I still don't like it.)
>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>> Updated patch attached.
>>>>>>>> Patch for tests is the same as previos.
>>>>>>
>>>>>> + validate_domain_name(value, allow_slash=True)
>>>>>> +
>>>>>> + #classless reverse zones can contain slash '/'
>>>>>> + normalized_zone = normalize_zone(value)
>>>>>> + if not zone_is_reverse(normalized_zone) and ('/' in
>>>>>> normalized_zone):
>>>>>> + return u"Only reverse zones can contain '/' in labels"
>>>>>>
>>>>>> You don't need to enclose "x in y" in parentheses. Also I don't think
>>>>>> there is any value in pointing out that slash can be used for reverse
>>>>>> zones when giving an error for non-reverse zones. I would prefer
>>>>>> something like this instead:
>>>>>>
>>>>>> normalized_zone = normalize_zone(value)
>>>>>> validate_domain_mame(value,
>>>>>> allow_slash=zone_is_reverse(normalized_zone))
>>>>>>
>>>>>>
>>>>>> + def _idnsname_pre_callback(self, ldap, dn, entry_attrs, *keys,
>>>>>> **options):
>>>>>> + #in reverse zone can a record name contains /, (and -)
>>>>>> +
>>>>>> + if self.is_pkey_zone_record(*keys):
>>>>>> + addr = u''
>>>>>> + else:
>>>>>> + addr = keys[-1]
>>>>>> +
>>>>>> + zone = keys[-2]
>>>>>> + zone = normalize_zone(zone)
>>>>>> + if (not zone_is_reverse(zone)) and ('/' in addr):
>>>>>> + raise errors.ValidationError(name='name',
>>>>>> + error=unicode(_('Only domain names in reverse zones
>>>>>> can contain \'/\'')) )
>>>>>>
>>>>>> I think you can do better (from the top of my head and untested):
>>>>>>
>>>>>> if not self.is_pkey_zone_record(*keys):
>>>>>> zone, addr = normalize_zone(keys[-2]), keys[-1]
>>>>>> try:
>>>>>> validate_domain_name(addr + zone,
>>>>>> allow_slash=zone_is_reverse(zone))
>>>>>> except ValueError, e:
>>>>>> raise errors.ValidationError(name='idnsname',
>>>>>> error=str(e))
>>>>>>
>>>>>>
>>>>>> + #Classless zones (0/25.0.0.10.in-addr.arpa.) -> skip check
>>>>>> + #zone has to be checked without reverse domain suffix
>>>>>> (in-addr.arpa.)
>>>>>> + if '/' in addr or '/' in zone or '-' in addr or '-' in zone:
>>>>>> + pass
>>>>>> + else:
>>>>>> + ip_addr_comp_count = addr_len + len(zone.split('.'))
>>>>>> + if ip_addr_comp_count != zone_len:
>>>>>> + raise errors.ValidationError(name='ptrrecord',
>>>>>> + error=unicode(_('Reverse zone %(name)s requires
>>>>>> exactly %(count)d IP address components, %(user_count)d given')
>>>>>> + % dict(name=zone_name, count=zone_len,
>>>>>> user_count=ip_addr_comp_count)))
>>>>>>
>>>>>> Is there anything preventing us from dropping this whole check? I don't
>>>>>> think it makes sense anymore.
>>>>>>
>>>>> IMO it doesnt have sense with classless reverse domains, but it is
>>>>> useful with classfull reverse domains, which are used more, to prevent
>>>>> users making mistakes.
>>>>
>>>> OK, but please use a simple if instead of if/pass/else.
>>>>
>>>>>
>>>>>>
>>>>>> IMHO validate_dns_label is very ugly. I would prefer if it looked
>>>>>> something like this instead (again, from the top of my head and untested):
>>>>>>
>>>>>> def validate_dns_label(dns_label, allow_underscore=False,
>>>>>> allow_slash=False):
>>>>>> base_chars = 'a-z0-9'
>>>>>> extra_chars = ''
>>>>>> middle_chars = ''
>>>>>>
>>>>>> if allow_underscore:
>>>>>> extra_chars += "_"
>>>>>> if allow_slash:
>>>>>> middle_chars += '/'
>>>>>>
>>>>>> middle_chars += '-'
>>>>>>
>>>>>> label_regex =
>>>>>> r'^[%(base)s%(extra)s]([%(base)s%(extra)%(middle)s]?[%(base)s%(extra)s])*$'
>>>>>> % dict(base=base_chars, extra=extra_chars, middle=middle_chars)
>>>>>> regex = re.compile(label_regex, re.IGNORECASE)
>>>>>>
>>>>>> if not dns_label:
>>>>>> raise ValueError(_('empty DNS label'))
>>>>>>
>>>>>> if len(dns_label) > 63:
>>>>>> raise ValueError(_('DNS label cannot be longer that 63
>>>>>> characters'))
>>>>>>
>>>>>> if not regex.match(dns_label):
>>>>>> chars = ', '.join('"%s"' % c for c in base_chars + extra_chars
>>>>>> + middle_chars)
>>>>>> chars2 = ', '.join('"%s"' % c for c in middle_chars)
>>>>>> raise ValueError(_('only letters, numbers, %(chars)s are
>>>>>> allowed. ' \
>>>>>> 'DNS label may not start or end with
>>>>>> %(chars2)s') \
>>>>>> % dict(chars=chars, chars2=chars2))
>>>>>>
>>>>>>
>>>>>
>>>>> Thank you for the review, I will fix it.
>>>>>
>>>>
>>>>
>>>
>>> All fixed. Patches attached.
>>>
>>
>> Thanks!
>>
>>
>> I see some new test failures caused by the error message change:
>>
>> ======================================================================
>> FAIL: test_netgroup[17]: netgroup_add_member: Add invalid host
>> u'+invalid&host' to netgroup u'netgroup1'
>> ----------------------------------------------------------------------
>> Traceback (most recent call last):
>> File "/usr/lib/python2.7/site-packages/nose/case.py", line 197, in
>> runTest
>> self.test(*self.arg)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 284, in <lambda>
>> func = lambda: self.check(nice, **test)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 298, in check
>> self.check_exception(nice, cmd, args, options, expected)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 324, in check_exception
>> assert_deepequal(expected.strerror, e.strerror)
>> File "/usr/lib/python2.7/site-packages/ipatests/util.py", line 352,
>> in assert_deepequal
>> VALUE % (doc, expected, got, stack)
>> AssertionError: assert_deepequal: expected != got.
>>
>> expected = u"invalid 'host': only letters, numbers, _, and - are
>> allowed. DNS label may not start or end with -"
>> got = u"invalid 'host': only letters, numbers, '_', '-' are allowed.
>> DNS label may not start or end with '-'"
>> path = ()
>>
>> ======================================================================
>> FAIL: test_netgroup[32]: netgroup_mod: Add invalid host u'+invalid&host'
>> to netgroup u'netgroup1' using setattr
>> ----------------------------------------------------------------------
>> Traceback (most recent call last):
>> File "/usr/lib/python2.7/site-packages/nose/case.py", line 197, in
>> runTest
>> self.test(*self.arg)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 284, in <lambda>
>> func = lambda: self.check(nice, **test)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 298, in check
>> self.check_exception(nice, cmd, args, options, expected)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 324, in check_exception
>> assert_deepequal(expected.strerror, e.strerror)
>> File "/usr/lib/python2.7/site-packages/ipatests/util.py", line 352,
>> in assert_deepequal
>> VALUE % (doc, expected, got, stack)
>> AssertionError: assert_deepequal: expected != got.
>>
>> expected = u"invalid 'externalhost': only letters, numbers, _, and -
>> are allowed. DNS label may not start or end with -"
>> got = u"invalid 'externalhost': only letters, numbers, '_', '-' are
>> allowed. DNS label may not start or end with '-'"
>> path = ()
>>
>> ======================================================================
>> FAIL: test_raduisproxy[21]: radiusproxy_mod: Set server string of
>> testradius to testradius.test:1:2:3 (invalid)
>> ----------------------------------------------------------------------
>> Traceback (most recent call last):
>> File "/usr/lib/python2.7/site-packages/nose/case.py", line 197, in
>> runTest
>> self.test(*self.arg)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 284, in <lambda>
>> func = lambda: self.check(nice, **test)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 298, in check
>> self.check_exception(nice, cmd, args, options, expected)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/xmlrpc_test.py",
>> line 324, in check_exception
>> assert_deepequal(expected.strerror, e.strerror)
>> File "/usr/lib/python2.7/site-packages/ipatests/util.py", line 352,
>> in assert_deepequal
>> VALUE % (doc, expected, got, stack)
>> AssertionError: assert_deepequal: expected != got.
>>
>> expected = u"invalid 'ipatokenradiusserver': only letters, numbers,
>> _, and - are allowed. DNS label may not start or end with -"
>> got = u"invalid 'ipatokenradiusserver': only letters, numbers, '_',
>> '-' are allowed. DNS label may not start or end with '-'"
>> path = ()
>>
>> ======================================================================
>> FAIL: Test adding an invalid external host to Sudo rule using
>> ----------------------------------------------------------------------
>> Traceback (most recent call last):
>> File "/usr/lib/python2.7/site-packages/nose/case.py", line 197, in
>> runTest
>> self.test(*self.arg)
>> File
>> "/usr/lib/python2.7/site-packages/ipatests/test_xmlrpc/test_sudorule_plugin.py",
>> line 500, in test_a_sudorule_mod_externalhost_invalid_addattr
>> "DNS label may not start or end with -")
>> AssertionError
>>
>>
>> And one nitpick: please don't add the extra newlines around
>> _domain_name_validator.
>>
>>
>> Honza
>>
>
> Thank you for review.
>
> Patches attached.
> Extra blank lines removed.
> The others test are fixed now.
>
ACK.
--
Jan Cholasta
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