[SSSD] [PATCHES][PRELIMINARY] sudo - new design

Pavel Březina pbrezina at redhat.com
Thu Jun 21 15:32:47 UTC 2012


On 3.6.2012 22:17, Pavel Březina wrote:
> On 14.5.2012 22:37, Jakub Hrozek wrote:
>> On Mon, May 14, 2012 at 06:39:30PM +0200, Pavel Březina wrote:
>>> On 9.5.2012 17:07, Pavel Březina wrote:
>>>> On 05/07/2012 07:13 PM, Pavel Březina wrote:
>>>>> On 04/23/2012 06:34 PM, Pavel Březina wrote:
>>>>>> On 04/23/2012 05:04 PM, Pavel Březina wrote:
>>>>>>> Hello everybody,
>>>>>>> here is the first set of patches for the new sudo clothes. [1]
>>>>>>>
>>>>>>> As it does not touch the responder, I believe it does not require
>>>>>>> the
>>>>>>> patches from the other preliminary sudo thread (already acked).
>>>>>>> However
>>>>>>> it was written atop them.
>>>>>>>
>>>>>>> [2/10]
>>>>>>> This is the main change for the async processing of the sudo
>>>>>>> rules. It
>>>>>>> make sdap_sudo_refresh_send() more generic by adding there two
>>>>>>> filters:
>>>>>>> ldap_filter - used for search in the LDAP
>>>>>>> sysdb_filter - used for a deletion of the rules from sysdb
>>>>>>>
>>>>>>> This way we can have many different refresh styles without touching
>>>>>>> this fundamental function.
>>>>>>>
>>>>>> > From this patch further the provider will return an error to the
>>>>>>> responder making it unusable.
>>>>>>>
>>>>>>> [...]
>>>>>>> The rest of the patches has a self-describing subject. Don't be
>>>>>>> afraid
>>>>>>> of the count, these patches are very small :-)
>>>>>>>
>>>>>>> The next set of patches is where the fun begin, so be patient :-)
>>>>>>>
>>>>>>> [1] https://fedorahosted.org/sssd/wiki/DesignDocs/SUDOCachingRules
>>>>>>
>>>>>> Ok, I made a mistake already in the 3rd patch, I'm sending it
>>>>>> again :)
>>>>>
>>>>> Sending new set of patches if you want to take a look.
>>>>>
>>>>> Full periodical updates should run fine, there are preparations for
>>>>> the
>>>>> smart update. I'm going to ignore modifyTimestamp for now and use only
>>>>> entryUSN if available.
>>>>>
>>>>> It also does not filter the rules by host, I plan to add it as one of
>>>>> the last things.
>>>>
>>>> The provider part is now complete except the above given limitations.
>>>
>>> Ok, the major changes are done in this patch set.
>>>
>>> What left is:
>>> - download rules per host, this only appends a filter to the search so
>>> it should not invoke any logic change
>>>
>>> - it ignores modifyTimestamp - simo suggested to use it in smart
>>> refresh when enabled in configuration and USN not available, but do
>>> we really want to use it? There is no other part in sssd that uses it
>>> (or am I wrong?).
>>>
>>
>> Pavel, I won't be able to review the huge patchset in a whole, so I
>> started with the first couple of patches. Do you know offhand if there is
>> a particular point where several patches could be applied and the
>> provider
>> would work so that when first N patches are acked, we can push them and
>> decrease the amount of rebasing?
>>
>> 0001: sudo ldap provider: move async routines to sdap_async_sudo.c
>> Ack, this patch just moves code around
>>
>> 0002: sudo ldap provider: give sdap_sudo_refresh_send() search and
>> purge filters
>> Ack. The sudo provider is not functional after this patch until patch #8,
>> but I think that's OK. This split is as good as any.
>>
>> 0003: confdb: add entry_cache_sudo_timeout option
>> Nack, the new option is missing from the configAPI
>> Also, I assume the new option is going to be used when the responder
>> changes land? So far, it's only read, not used.
>
> Your assumption is correct.
> Done. I have also fixed it in subsequent patches. I really need to
> write it somewhere on my desk :-)
>
>> 0004: sudo ldap provider: add sysdb ctx in sdap_sudo_refresh_state
>> Ack, but I don't get the point?
>>
>> 0005: sudo ldap provider: add domain info in sdap_sudo_refresh_state
>> Same as 0004, what's the intent?
>
> Just to shorten access to these contexts.
>
>> 0006: sudo ldap provider: add expiration time to each rule
>> Ack
>>
>> 0007: sysdb_sudo_set_refresh_time
>> Looks good, but do you anticipate that sysdb_sudo_{get,set}_refresh_time
>> would be called with any other attribute name than
>> SYSDB_SUDO_AT_LAST_FULL_REFRESH?
>
> Originally it should contain SYSDB_SUDO_AT_LAST_SMART_REFRESH but I
> found out later that it is not necessary.
>
> The intention was to use that value to compute when the first smart
> refresh should be scheduled after sssd is started. However, it needs to
> know the current highest USN value (which would be a little tricky).
> Therefore I'm doing full refresh at first and then enable periodical
> smart updates (as we have discussed on site).
>
>>
>> 0008: sudo ldap provider: provide API for full refresh
>> +
>> + /* free filters with the request */
>> + talloc_steal(subreq, ldap_filter);
>> + talloc_steal(subreq, sysdb_filter);
>> +
>>
>> Do the filters need to outlive the top-level request? It doesn't look
>> like
>> it's the case, but if so, then I would say it's more natural to strdup
>> them
>> in the subreq, so that other potential consumers of
>> sdap_sudo_refresh_send()
>> don't need to remember to steal the filters.
>
> Well, you don't really need to steal them. But I don't have any use for
> them outside the subreq so I think it is correct to make them
> deallocate with subreq.
>
> Those are constant input data, so there is no need to strdup them.
>
>> _recv should come after _done in the source file, otherwise the code
>> reads funny.
>
> Ok. There would be unworthy rebasing troubles, thus I have moved it in
> a new patch.
>
>> In sdap_sudo_full_refresh_done(), you read the req and state variables
>> twice
>> in the patch, but not in the resulting code, so I assume it was fixed in
>> a follow-up patch. Is it too much trouble to fix? If it is, don't bother.
>
> This is an error from one of many rebases I have done.
> Fixed.
>
>> I think you meant to quit the request here with an error? If not, please
>> put a comment saying that you ignore an error intentionally:
>> + if (ret != EOK) {
>> + DEBUG(SSSDBG_MINOR_FAILURE, ("Unable to save time of "
>> + "a successful full refresh\n"));
>> + }
>
> I have added the following comment:
> /* this is only a minor error that does not affect the functionality,
> * therefore there is no need to report it with tevent_req_error()
> * which would cause problems in the consumers */
>
>> 0009: sudo ldap provider: add support for on demand full refresh
>> + default:
>> + DEBUG(SSSDBG_CRIT_FAILURE, ("Invalid request type: %d\n",
>> + sudo_req->type));
>> + }
>> I think you should abort the request with something like EINVAL here.
>> I know that the code would not continue because of the following (req
>> != NULL)
>> check but the OOM error would be pretty confusing for the caller.
>
> Yes, definitely. The same problem was also in sdap_sudo_reply() where
> ret would be uninitialized in ret != EOK condition.
> Both fixed.
>
>>
>> 0010: provide API for refresh of specific rules
>> Same comment with stealing the filters as with patch #9. Frankly, I don't
>> really like how you wrapped sdap_sudo_refresh_send(). Wouldn't it be more
>> readable to create both _done and _recv?
>
> I found it necessary after all, because I needed to create there a new
> request. It is converted to it in one of the last patches.
>
>> 0011: sudo ldap provider: add support for on demand refresh of
>> specific rules
>> Ack
>>
>> I'm going to continue tomorrow. I also haven't done any testing yet, just
>> reading the code.
>
> I have also fixed typo in man page and added new patch that handles
> modification of the highest USN value after a specific rules refresh.
>
> New patches are attached.
>
> Thanks for the review. Keep coming :-)

Rebased on the current master and patches from "sudo: send username and
uid while requesting default options" thread.
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