[SSSD] [PATCH] ad: support cross domain membership

Jakub Hrozek jhrozek at redhat.com
Wed Oct 30 21:39:23 UTC 2013


On Wed, Oct 30, 2013 at 10:05:42PM +0100, Sumit Bose wrote:
> On Wed, Oct 30, 2013 at 03:21:16PM +0100, Pavel Březina wrote:
> > On 10/29/2013 01:43 PM, Pavel Březina wrote:
> > >On 10/28/2013 10:00 PM, Sumit Bose wrote:
> > >>On Mon, Oct 28, 2013 at 04:51:27PM +0100, Jakub Hrozek wrote:
> > >>>On Fri, Oct 25, 2013 at 10:40:28PM +0200, Jakub Hrozek wrote:
> > >>>>On Fri, Oct 25, 2013 at 10:33:42PM +0200, Pavel Březina wrote:
> > >>>>>On 10/25/2013 10:24 PM, Pavel Březina wrote:
> > >>>>>>On 10/25/2013 08:10 PM, Jakub Hrozek wrote:
> > >>>>>>>On Fri, Oct 25, 2013 at 01:47:51PM -0400, Pavel Brezina wrote:
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>----- Original Message -----
> > >>>>>>>>>From: "Jakub Hrozek" <jhrozek at redhat.com>
> > >>>>>>>>>To: sssd-devel at lists.fedorahosted.org
> > >>>>>>>>>Sent: Friday, October 25, 2013 4:01:03 PM
> > >>>>>>>>>Subject: Re: [SSSD] [PATCH] ad: support cross domain membership
> > >>>>>>>>>
> > >>>>>>>>>On Fri, Oct 25, 2013 at 03:27:40PM +0200, Pavel Březina wrote:
> > >>>>>>>>>>On 10/25/2013 02:22 PM, Jakub Hrozek wrote:
> > >>>>>>>>>>>On Fri, Oct 25, 2013 at 12:58:23PM +0200, Pavel Březina wrote:
> > >>>>>>>>>>>>On 10/25/2013 10:55 AM, Pavel Březina wrote:
> > >>>>>>>>>>>>>On 10/24/2013 08:40 PM, Jakub Hrozek wrote:
> > >>>>>>>>>>>>>>On Wed, Oct 02, 2013 at 04:13:32PM +0200, Pavel Březina
> > >>>>>>>>>>>>>>wrote:
> > >>>>>>>>>>>>>>>On 10/01/2013 09:54 PM, Jakub Hrozek wrote:
> > >>>>>>>>>>>>>>>>On Tue, Sep 24, 2013 at 03:17:47PM +0200, Pavel Březina
> > >>>>>>>>>>>>>>>>wrote:
> > >>>>>>>>>>>>>>>>>On 09/24/2013 01:32 PM, Jakub Hrozek wrote:
> > >>>>>>>>>>>>>>>>>>On Wed, Sep 11, 2013 at 02:40:14PM +0200, Pavel
> > >>>>>>>>>>>>>>>>>>Březina wrote:
> > >>>>>>>>>>>>>>>>>>>https://fedorahosted.org/sssd/ticket/2064
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>These patch set depends on: [PATCH] ad: store group in
> > >>>>>>>>>>>>>>>>>>>correct
> > >>>>>>>>>>>>>>>>>>>tree on initgroups via tokenGroups
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>You can also pull it with all dependencies from my
> > >>>>>>>>>>>>>>>>>>>repository:
> > >>>>>>>>>>>>>>>>>>>fedorapeople.org:public_git/sssd.git #ad-groups
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>The fundamental changes in this patch set are: - lookup
> > >>>>>>>>>>>>>>>>>>>groups
> > >>>>>>>>>>>>>>>>>>>in global catalog - pick up member domain from its
> > >>>>>>>>>>>>>>>>>>>originalDN
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>From 0273d17f24eac7b60dfc0515a9e3b97ad16d1199 Mon Sep 17
> > >>>>>>>>>>>>>>>>>>>00:00:00 2001 From: =?UTF-8?q?Pavel=20B=C5=99ezina?=
> > >>>>>>>>>>>>>>>>>>><pbrezina at redhat.com> Date: Mon, 9 Sep 2013 15:52:03
> > >>>>>>>>>>>>>>>>>>>+0200
> > >>>>>>>>>>>>>>>>>>>Subject: [PATCH 1/9] ad: shortcut if possible during get
> > >>>>>>>>>>>>>>>>>>>object
> > >>>>>>>>>>>>>>>>>>>by ID or SID
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>When getByID or getBySID comes from responder, the
> > >>>>>>>>>>>>>>>>>>>request
> > >>>>>>>>>>>>>>>>>>>doesn't necessarily have to contain correct domain,
> > >>>>>>>>>>>>>>>>>>>since
> > >>>>>>>>>>>>>>>>>>>responder iterates over all domains until it finds a
> > >>>>>>>>>>>>>>>>>>>match.
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>Every domain has its own ID range, so we can simply
> > >>>>>>>>>>>>>>>>>>>shortcut
> > >>>>>>>>>>>>>>>>>>>if domain does not match and avoid LDAP round trip.
> > >>>>>>>>>>>>>>>>>>>Responder
> > >>>>>>>>>>>>>>>>>>>will continue with next domain until it finds the
> > >>>>>>>>>>>>>>>>>>>correct
> > >>>>>>>>>>>>>>>>>>>one.
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>This patch seems OK to me, but I'd like a second look
> > >>>>>>>>>>>>>>>>>>from
> > >>>>>>>>>>>>>>>>>>someone who understands the ranges better (which is
> > >>>>>>>>>>>>>>>>>>probably
> > >>>>>>>>>>>>>>>>>>Sumit)
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>From f74d4637980438032649dfbf079fa6c839862586 Mon Sep 17
> > >>>>>>>>>>>>>>>>>>>00:00:00 2001 From: =?UTF-8?q?Pavel=20B=C5=99ezina?=
> > >>>>>>>>>>>>>>>>>>><pbrezina at redhat.com> Date: Tue, 10 Sep 2013 10:40:06
> > >>>>>>>>>>>>>>>>>>>+0200
> > >>>>>>>>>>>>>>>>>>>Subject: [PATCH 2/9] ad: simplify get_conn_list()
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>It was originally design to return list of connection
> > >>>>>>>>>>>>>>>>>>>objects,
> > >>>>>>>>>>>>>>>>>>>it really always work with only one connection.
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>I'd like to review this patch and the following along
> > >>>>>>>>>>>>>>>>>>with my
> > >>>>>>>>>>>>>>>>>>patches to look up POSIX IDs in GC, they touch the
> > >>>>>>>>>>>>>>>>>>same code.
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>From ad5dc9e7557ef605fc5d7fc759e5cb6c2f9a148c Mon Sep 17
> > >>>>>>>>>>>>>>>>>>>00:00:00 2001 From: =?UTF-8?q?Pavel=20B=C5=99ezina?=
> > >>>>>>>>>>>>>>>>>>><pbrezina at redhat.com> Date: Tue, 10 Sep 2013 14:45:50
> > >>>>>>>>>>>>>>>>>>>+0200
> > >>>>>>>>>>>>>>>>>>>Subject: [PATCH 4/9] sdap_domain_add(): fix possible
> > >>>>>>>>>>>>>>>>>>>memory
> > >>>>>>>>>>>>>>>>>>>leak
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>ACK.
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>From 9f2c212e01700289d70002c8c39b732ca6c11cee Mon Sep 17
> > >>>>>>>>>>>>>>>>>>>00:00:00 2001 From: =?UTF-8?q?Pavel=20B=C5=99ezina?=
> > >>>>>>>>>>>>>>>>>>><pbrezina at redhat.com> Date: Tue, 10 Sep 2013 14:45:52
> > >>>>>>>>>>>>>>>>>>>+0200
> > >>>>>>>>>>>>>>>>>>>Subject: [PATCH 5/9] sdap: store base dn in sdap_domain
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>Groups may contain members from different domains.
> > >>>>>>>>>>>>>>>>>>>Remembering
> > >>>>>>>>>>>>>>>>>>>base dn in domain object gives us the ability to simply
> > >>>>>>>>>>>>>>>>>>>lookup
> > >>>>>>>>>>>>>>>>>>>correct domain by comparing object dn with domain
> > >>>>>>>>>>>>>>>>>>>base dn.
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>Resolves: https://fedorahosted.org/sssd/ticket/2064
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>I haven't tested these patches yet.
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>I'm sending rebased version of my patches.
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>[PATCH 4/9] sdap_domain_add(): fix possible memory leak
> > >>>>>>>>>>>>>>>>>was
> > >>>>>>>>>>>>>>>>>removed
> > >>>>>>>>>>>>>>>>>from the patch set since recent Sumit's patch removed the
> > >>>>>>>>>>>>>>>>code I
> > >>>>>>>>>>>>>>>>>fixed :-)
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>Hi,
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>can you check if patches #6 and #7 still apply after the
> > >>>>>>>>>>>>>>>>recent
> > >>>>>>>>>>>>>>>>changes in 1.11 ? We actually do use the LDAP fallback
> > >>>>>>>>>>>>>>>>now..
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>They won't apply, but I think it is quite all right to just
> > >>>>>>>>>>>>>>>skip them.
> > >>>>>>>>>>>>>>>The purpose of these patches was to always contact GC for
> > >>>>>>>>>>>>>>>get_group
> > >>>>>>>>>>>>>>>and
> > >>>>>>>>>>>>>>>initgroups.
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>We always contact GC first at the moment and having LDAP as
> > >>>>>>>>>>>>>>>fallback
> > >>>>>>>>>>>>>>>is
> > >>>>>>>>>>>>>>>fine for groups. If there will be a member from different
> > >>>>>>>>>>>>>>>domain, we
> > >>>>>>>>>>>>>>>will just fail - but if there won't be foreign member it
> > >>>>>>>>>>>>>>>will
> > >>>>>>>>>>>>>>>work.
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>Hi,
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>In general the patches look good to me but I think the first
> > >>>>>>>>>>>>>>two can be
> > >>>>>>>>>>>>>>simplified.
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>Instead of magically trying to find the base DN from the
> > >>>>>>>>>>>>>>entry's
> > >>>>>>>>>>>>>>original DN, I think we can simplify it to:
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>struct sdap_domain *
> > >>>>>>>>>>>>>>sdap_domain_get_by_dn(struct sdap_options *opts,
> > >>>>>>>>>>>>>>                       const char *dn)
> > >>>>>>>>>>>>>>{
> > >>>>>>>>>>>>>>     struct sdap_domain *sditer = NULL;
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>     DLIST_FOR_EACH(sditer, opts->sdom) {
> > >>>>>>>>>>>>>>         if (sss_ldap_dn_in_search_bases(tmp_ctx, dn,
> > >>>>>>>>>>>>>>sditer->search_bases, NULL) ||
> > >>>>>>>>>>>>>>             sss_ldap_dn_in_search_bases(tmp_ctx, dn,
> > >>>>>>>>>>>>>>sditer->user_search_bases, NULL) ||
> > >>>>>>>>>>>>>>             sss_ldap_dn_in_search_bases(tmp_ctx, dn,
> > >>>>>>>>>>>>>>sditer->group_search_bases, NULL)) {
> > >>>>>>>>>>>>>>             return sditer;
> > >>>>>>>>>>>>>>         }
> > >>>>>>>>>>>>>>     }
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>     return NULL;
> > >>>>>>>>>>>>>>}
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>Then you won't need to store the base DN, no need for the
> > >>>>>>>>>>>>>>magic
> > >>>>>>>>>>>>>>with
> > >>>>>>>>>>>>>>strstr
> > >>>>>>>>>>>>>>and the code will work even for custom search bases.
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>>Hi,
> > >>>>>>>>>>>>>new patches are attached. I just added all of the search
> > >>>>>>>>>>>>>bases.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>>And here's one more iteration. While working on token groups
> > >>>>>>>>>>>>patches
> > >>>>>>>>>>>>I found a bug in the first patch. I tried to shortcut using id
> > >>>>>>>>>>>>mapping even if id mapping is disabled. This made the posix
> > >>>>>>>>>>>>groups
> > >>>>>>>>>>>>unresolvable since id mapping returned an error when trying
> > >>>>>>>>>>>>to map
> > >>>>>>>>>>>>GID to SID.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>>Thanks. See also one more attached patch I applied on top of
> > >>>>>>>>>>>yours to
> > >>>>>>>>>>>make cross-domain group resolution work. I'm still chasing
> > >>>>>>>>>>>one bug in
> > >>>>>>>>>>>fill_members that might cause some members to be not qualified,
> > >>>>>>>>>>>though.
> > >>>>>>>>>>
> > >>>>>>>>>>Hi,
> > >>>>>>>>>>ack to this patch. The problem was when you have:
> > >>>>>>>>>>group at subad : user at parentad
> > >>>>>>>>>>it did not find it. Jakub's patch fixes it.
> > >>>>>>>>>>
> > >>>>>>>>>>There is still one problem that was introduce by the change of
> > >>>>>>>>>>sdap_domain_get_by_dn to search bases instead of string
> > >>>>>>>>>>comparison.
> > >>>>>>>>>>
> > >>>>>>>>>>We have domains:
> > >>>>>>>>>>ad.pb -> sub.ad.pb
> > >>>>>>>>>>
> > >>>>>>>>>>Search bases:
> > >>>>>>>>>>ad.pb: dc=ad,dc=pb
> > >>>>>>>>>>sub.ad.pb: dc=sub,dc=ad,dc=pb
> > >>>>>>>>>>
> > >>>>>>>>>>User:
> > >>>>>>>>>>cn=user,dc=sub,dc=ad,dc=pb
> > >>>>>>>>>>
> > >>>>>>>>>>This user belongs to sub.ad.pb but its dn match with
> > >>>>>>>>>>dc=ad,dc=pb and
> > >>>>>>>>>>as a result we will assign him to domain ad.pb.
> > >>>>>>>>>>
> > >>>>>>>>>>We can either swap back to my original patches or tune
> > >>>>>>>>>>sss_ldap_dn_in_search_bases() so it returns expected result
> > >>>>>>>>>>for this
> > >>>>>>>>>>situation (it will require all dc parts to match).
> > >>>>>>>>>
> > >>>>>>>>>I would prefer the latter. Just remove the RDN and return true
> > >>>>>>>>>only if
> > >>>>>>>>>the rest matches.
> > >>>>>>>>
> > >>>>>>>>Comparing only the part after RDN is not sufficient.
> > >>>>>>>>
> > >>>>>>>>dn: cn=Joe,cn=Manager,cn=Users,dc=example,dc=com
> > >>>>>>>>rdn: cn=Joe
> > >>>>>>>>search base: dc=example,dc=com
> > >>>>>>>>
> > >>>>>>>>strcmp(cn=Manager,cn=Users,dc=example,dc=com, dc=example,dc=com)
> > >>>>>>>>!= 0
> > >>>>>>>>
> > >>>>>>>>We would have to use similar "magic" to locate domain part of
> > >>>>>>>>both dn
> > >>>>>>>>that you did not like.
> > >>>>>>>
> > >>>>>>>Well, the main reason I didn't like the original patches was that
> > >>>>>>>they
> > >>>>>>>were hardcoding "DC=". Sure, that works for AD, but I don't like
> > >>>>>>>these
> > >>>>>>>hacks in the generic LDAP code.
> > >>>>>>>
> > >>>>>>>Could we modify sdap_domain_get_by_dn() so that it would try to
> > >>>>>>>match as
> > >>>>>>>much as possible?
> > >>>>>>>
> > >>>>>>>btw latest patches based on your patchset are attached. I added two
> > >>>>>>>fixes in the NSS responder that I needed to get getent reporting the
> > >>>>>>>right members.
> > >>>>>>
> > >>>>>>We agreed with Jakub to go with original approach for the moment.
> > >>>>>>Here
> > >>>>>>is the current working patchset. The latest Jakub's patch contains
> > >>>>>>a bug
> > >>>>>>when no members are printed. We didn't find the root of this bug yet,
> > >>>>>>but we need to leave it for a fresh day.
> > >>>>>
> > >>>>>And one more time, now with Sumit's note addressed.
> > >>>>
> > >>>>I have filed a ticket for fixing the nss responder -
> > >>>>https://fedorahosted.org/sssd/ticket/2131
> > >>>>
> > >>>>And one more to improve detecting the search bases -
> > >>>>https://fedorahosted.org/sssd/ticket/2132
> > >>>>
> > >>>>I bypassed triage and put them directly to the 1.11.x bucket as they
> > >>>>improve on existing feature.
> > >>>
> > >>>The testing itself went fine, but patch #1 didn't even compile. Attached
> > >>>are patches after I amended them, only patch #1 changed.
> > >
> > >Thanks. I forgot to commit this change.
> > >
> > >>
> > >>After sdap_domain_get_by_dn() is called it is always checked if NULL is
> > >>returned and if yes the current domain is set. Maybe it would make the
> > >>code easier if a default return value is added to the parameter list of
> > >>sdap_domain_get_by_dn().
> > >
> > >I don't think so. We are searching for an sdap_domain that is converted
> > >to sss_domain_info by caller. The default sdap domain is not available
> > >in the code that references this function so we would have to amend the
> > >code in order to obtain it and pass it to sdap_domain_get_by_dn() (more
> > >code) or hard code sdap_domain_get_by_dn() to return the head of sdap
> > >domain list (not nice).
> > >
> > >I think it is better this way, that it returns NULL if it cannot match
> > >dn with domain and let the caller decide how to continue.
> > >
> > >>I think we should mention somewhere that cross domain group memberships
> > >>are supported but will currently only work for AD GC lookups or other
> > >>environments which use dc=-style based DNs.
> > >
> > >Well, since we don't support other subdomains than AD I don't think it
> > >is needed. Such documentation may actually imply that we support other
> > >LDAP servers as subdomains as well.
> > >
> > >>If the DLIST_FOR_EACH loop in sdap_nested_member_is_ent() is never run
> > >>ret is uninitialized.
> > >
> > >Nice catch, I amended Jakub's patch.
> > 
> > I reworked the first patch and put the huge branch into separate
> > function. See if you like it.
> > 
> > If not, I need to send another version of the original since it
> > unfortunately contains two bugs that I found now - didn't free sid
> > obtained from idmap and didn't set errno to zero before calling
> > strtouint.
> > 
> > 
> 
> I like the new one better and didn't found any regression during my
> testing, so ACK.
> 
> bye,
> Sumit

I haven't found any bug in the patches either (just the issue with the
ad_filter) so ack++

For the record, I tested:
    getent passwd user at root.domain
    getent passwd user at sub.domain
    getent group gr at root.domain (mixed membership)
    getent group gr at sub.domain  (mixed membership)
    id user at root.domain (mixed membership)
    id user at sub.domain (mixed membership)



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