[Freeipa-devel] [PATCHES 0024, 0025] Classless support for reverse domains
Jan Cholasta
jcholast at redhat.com
Tue Feb 11 14:42:20 UTC 2014
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
--
Jan Cholasta
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