[Freeipa-devel] [PATCH] 16 Netgroup nisdomain and hosts validation

[Martin Kosek]

On Fri, 2012-03-23 at 23:10 +0100, Ondrej Hamada wrote:
> On 03/15/2012 08:13 AM, Martin Kosek wrote:
> > On Wed, 2012-03-14 at 16:54 +0100, Ondrej Hamada wrote:
> >> On 03/09/2012 04:34 PM, Martin Kosek wrote:
> >>> On Thu, 2012-03-08 at 14:52 +0100, Ondrej Hamada wrote:
> >>>> Netgroup nisdomain and hosts validation
> >>>>
> >>>> nisdomain validation:
> >>>> Added pattern to the 'nisdomain' parameter to validate the specified
> >>>> nisdomain name. According to most common use cases the same patter as
> >>>> for netgroup should fit. Unit-tests added.
> >>>>
> >>>> https://fedorahosted.org/freeipa/ticket/2447
> >>>>
> >>>> hosts validation:
> >>>> Added precallback to netgroup_add_member. It validates the specified
> >>>> hostnames and raises ValidationError exception for invalid hostnames.
> >>>> Unit-test added.
> >>>>
> >>>> https://fedorahosted.org/freeipa/ticket/2448
> >>> I checked the host validation part and it could be improved. Issue
> >>> described in #2447 (you have switched the ticket IDs) affects all
> >>> objects that allow external hosts, users, ..., i.e. those who call
> >>> add_external_post_callback in their post_callback.
> >>>
> >>> Should we fix all of these when we deal with this issue? Otherwise user
> >>> could do something like this:
> >>> # ipa sudorule-add-user foo --users=a+b
> >>>     Rule name: foo
> >>>     Enabled: TRUE
> >>>     External User: a+b
> >>>
> >>> We could create a similar function called add_external_pre_callback()
> >>> and pass it attribute name and validating function (which would be
> >>> common with the linked object). It would then do the validation for all
> >>> these affected objects consistently and without redundant code.
> >>>
> >>> I didn't liked much the implemented pre_callback anyway
> >>>
> >>> +    def pre_callback(self, ldap, dn, found, not_found, *keys,
> >>> **options):
> >>> +        # validate entered hostnames
> >>> +        if 'host' in options:
> >>> +            invalid_hostnames=[]
> >>> +            for hostname in options['host']:
> >>> +                try:
> >>> +                    validate_hostname(hostname, False)
> >>> +                except ValueError:
> >>> +                    invalid_hostnames.append(hostname)
> >>> +            if invalid_hostnames:
> >>> +                raise errors.ValidationError(name='host',
> >>> error='hostnames:\"%s\" contain invalid characters' %
> >>> ','.join(invalid_hostnames))
> >>> +        return dn
> >>>
> >>> I would rather raise the ValidationError with the first invalid hostname
> >>> and tell what's wrong (function validate_hostname tells it to you). If
> >>> you go with the proposed approach, you wouldn't have to deal with
> >>> formatting error messages, you would just raise the one returned by the
> >>> validator shared with the linked LDAP object (hostname, user, ...).
> >>>
> >>> Martin
> >> external_pre_callback function seems as a good idea, but there is a
> >> problem how to get the validators for various LDAP objects. For the
> >> hostname we already have one in ipalib.utils, but for the uid or group
> >> name we use only patterns specified in the parameter objects.
> >>
> >> Below I propose solution how to use the already defined parameter
> >> objects for validation (the only problem is that I have to assume, that
> >> it is always the first parameter in takes_params). Do you think this is
> >> a good approach?
> > I think the approach is OK, it can just be much improved in order to get
> > rid of the hardcoded parts. See comments below.
> >
> >> def add_external_pre_callback(memberattr, membertype, externalattr,
> >> ldap, dn, found, not_found, *keys, **options):
> >>       """
> >>       Pre callback to validate external members.
> >>       """
> >>       if membertype in options:
> >>           validator = api.Object[membertype].takes_params[0]
> > You can use api.Object[membertype].params[memberattr]
> >
> >>           for value in options[membertype]:
> >>               try:
> >>                   validator(value)
> >>               except errors.ValidationError as e:
> >>                   error_msg = e[(e.find(':')+1):]
> > You don't have to parse error message, you can just use e.name or
> > e.error right from the caught ValidationError.
> >
> >>                   raise errors.ValidationError(name=membertype,
> >> error=e[e.find(':')+1:])
> >>       return dn
> >>
> >
> 
> nisdomain validation:
> Added pattern to the 'nisdomain' parameter to validate the specified
> nisdomain name. According to most common use cases the same pattern as
> for netgroup should fit. Unit-tests added.
> 
> https://fedorahosted.org/freeipa/ticket/2448
> 
> 'add_external_pre_callback' function was created to allow validation of
> all external members. Validation is based on usage of objects primary
> key parameter. The 'add_external_pre_callback' fucntion has to be called
> directly from in the 'pre_callback' function. This change affects
> netgroup, hbacrule and sudorule commands.
> 
> Special validator is used only for hostname, the validator requires 
> fully qualified
> domain name and enables the hostnames to contain underscores.
> 
> Unit-tests added.
> 
> https://fedorahosted.org/freeipa/ticket/2447
> 

This is better, but I still see few issues:

1) You copied hostname validator instead of extending validate_hostname
function in ipalib.util with allow_underscore parameter which is already
available in validate_dns_label. Having duplicate functions like this is
just wrong and can lead to errors in future.

2) I also wonder if externalHost can contain non-fqdn hosts. In such
case, you would just add check_fqdn=False to validate_hostname.

Martin