[SSSD] [PATCHES] Support for multiple LDAP search bases

Jan Zelený jzeleny at redhat.com
Tue Oct 18 13:02:15 UTC 2011


> > On Tue, 2011-10-04 at 08:04 -0400, Stephen Gallagher wrote:
> > > On Tue, 2011-10-04 at 12:55 +0200, Jan Zelený wrote:
> > > > > On Mon, 2011-10-03 at 14:51 -0400, Stephen Gallagher wrote:
> > > > > > These patches add support for multiple search bases for users and
> > > > > > groups in both direct-lookup and enumeration modes.
> > > > > > 
> > > > > > Addresses https://fedorahosted.org/sssd/ticket/868
> > > > > > 
> > > > > > Some notes: There is no patch adding multiple search base support
> > > > > > for group lookups in RFC2307bis because it's meaningless right
> > > > > > now. Since the group memberships are direct DNs, we do all of our
> > > > > > searches as base searches, ignoring group_search_base. There is a
> > > > > > separate ticket, https://fedorahosted.org/sssd/ticket/960 that
> > > > > > will need to address this, taking advantage of the multiple
> > > > > > search base features.
> > > > > > 
> > > > > > Also, while working through this, I opened
> > > > > > https://fedorahosted.org/sssd/ticket/1006 as I noticed that we
> > > > > > are using far too many separate transactions while processing
> > > > > > RFC2307bis (which is likely the cause of the extreme slowdown
> > > > > > that some of our users were reporting with AD).
> > > > > > 
> > > > > > These patches don't really work separately, but they've been
> > > > > > broken up to make review much easier.
> > > > > > 
> > > > > > 
> > > > > > Patch 0001: Remove some unused options in a struct
> > > > > > 
> > > > > > Patch 0002: Fix size return for split_on_separator()
> > > > > > It was returning the size of the array, rather than the number of
> > > > > > elements. (The array was NULL-terminated). This argument was only
> > > > > > used in one place that was actually working around this odd
> > > > > > return value.
> > > > > > 
> > > > > > Patch 0003: Make sdap_get_id_specific_filter() more strict
> > > > > > Just makes it take const char * instead of char *.
> > > > > > 
> > > > > > Patch 0004: Add parser for multiple search bases
> > > > > > As discussed on the list, this will the ldap_*_search_base
> > > > > > options in the form of:
> > > > > > search_base[?scope?[filter][?search_base?scope?[filter]]*]
> > > > > > This is backwards-compatible (just use a search base)
> > > > > > 
> > > > > > Patch 0005: Add support for multiple search bases for users
> > > > > > 
> > > > > > Patch 0006: Add support for multiple search bases for netgroups
> > > > > > 
> > > > > > Patch 0007: Add support for multiple search bases for RFC2307
> > > > > > groups
> > > > > > 
> > > > > > Patch 0008: Add support for multiple search bases for initgroups
> > > > > > (user portion)
> > > > > > 
> > > > > > Patch 0009: Add support for multiple search bases for initgroups
> > > > > > (RFC2307 group portion)
> > > > > > 
> > > > > > Patch 0010: Add support for multiple search bases for initgroups
> > > > > > (RFC2307 group portion)
> > > > > > This patch I'm not 100% sure of. It may need more processing.
> > > > > > With RFC2307, it was safe to have duplicate groups in the list,
> > > > > > because only the group name is important (and we guarantee that
> > > > > > the name list has only unique values before saving it). With
> > > > > > RFC2307bis, I'm not sure if it's safe to add two groups that may
> > > > > > have the same name. Comments welcome.
> > > > > > 
> > > > > > Patch 0011: Update manpages with multiple search base information
> > > > > > 
> > > > > > Patch 0012: Convert ldap_*_search_filter
> > > > > > Instead of making this a global option for all user lookups, make
> > > > > > it only used if the search base is passed without an explicit
> > > > > > filter. The idea here is to deprecate the old separate
> > > > > > ldap_user_search_filter and ldap_group_search_filter options in
> > > > > > favor of the new representation (which is closer to the
> > > > > > traditional nss_ldap representation).
> > > > > > 
> > > > > > Patch 0013: Add support for multiple search bases for user
> > > > > > enumeration
> > > > > > 
> > > > > > Patch 0014: Add support for multiple search bases for group
> > > > > > enumeration This changes our behavior slightly with regard to
> > > > > > handling direct lookups that return more than one entry. In the
> > > > > > old code, we had a bug that would cause SSSD to treat this as an
> > > > > > enumeration (instead of a direct lookup). This was a bug and has
> > > > > > been fixed incidentally as part of this modification.
> > > > > 
> > > > > For the record, because I forgot to mention it in my first email: I
> > > > > tried to reproduce the issue jzeleny saw in the earlier thread
> > > > > without success. Either I inadvertently fixed it with the changes I
> > > > > made or it was caused by other changes in his environment (possibly
> > > > > the memberOf work).
> > > > > 
> > > > > I tested it with exactly the same users and groups, using SSSD
> > > > > speaking to a FreeIPA server (in both rfc2307bis mode and ipa
> > > > > backend).
> > > > > 
> > > > > 
> > > > > 
> > > > > His original comment:
> > > > > 
> > > > > So NACK after all. Following test failed:
> > > > > 
> > > > > I tried following membership structure. I have 3 groups: topgroup,
> > > > > middlegroup
> > > > > and bottomgroup and 2 users:  user1 and user2
> > > > > 
> > > > > The relationship is following:
> > > > > topgroup -> middlegroup, user1
> > > > > middlegroup -> user2, bottomgroup
> > > > > bottomgroup -> user1
> > > > > 
> > > > > 
> > > > > getent group topgroup gives me result with no members, the same
> > > > > test on master
> > > > > returns the expected result.
> > > > 
> > > > Stephen,
> > > > I still see the same error I reported. This time I had time to take a
> > > > look into logs and I found out that with your patches, a lookup on
> > > > IPA server is performed on the entire tree whereas the lookup
> > > > without your patch is performed only on cn=accounts subtree. As a
> > > > result, the lookup with your patches finds two group records (one in
> > > > cn=accounts and one in cn=compat) and refuses to continue. I have no
> > > > ldap search base configured manually, it is taken from IPA server.
> > > 
> > > Yeah, this is a bug in FreeIPA. If we use autodetection in FreeIPA
> > > right now, it returns the common search base for both compat and
> > > standard. It's not an SSSD issue. I've opened
> > > https://fedorahosted.org/freeipa/ticket/1919 upstream to deal with
> > > this. In the meantime, please just set the search base appropriately
> > > (which is done automatically by ipa-client-install).
> > 
> > Well, I have a bit of egg on my face. Jan was completely right, and I
> > had forgotten to ensure that the IPA provider was picking up the correct
> > search bases. I've now updated patch 0004 to correct this.
> 
> Steve,
> I finally finished the review:
> 
> #1-9: ACK
> 
> #11:
> - mention what other values are acceptable for scope (you have only subtree
> in the example)
> - maybe mention a reference to a document about LDAP filters? Or a brief
> description how the filter can look like. This is not necessary, just a
> thought to avoid some user questions in the future.
> 
> 
> 
> Consider following patches ACKed, I leave suggested changes at your
> discretion:
> 
> #10:
> sdap_initgr_rfc2307bis_send
> - how about making one fail/done label and some gotos?
> sdap_initgr_rfc2307bis_process
> - I'd rather use memcpy than the cycle
> 
> #13:
> sdap_get_users_process
> - I'd rather use memcpy than the cycle
> 
> #14:
> sdap_get_groups_process
> - I'd rather use memcpy than the cycle

Implementing multiple search bases into IPA provider, I noticed today 
something else in patch #0006.

in function sdap_get_netgroups_process() you call talloc_zfree() on two 
variables. I believe both of those are redundant:
- if count is zero then state->netgroups will be NULL
- state->filter is either freed in repeated call of 
sdap_get_netgroups_next_base() or it will be freed with the entire context due 
to an error.

I noticed similar code also being in patches #0005, #0007, #0008, however I 
didn't inspect it very deeply there, so I don't know for sure that it is 
redundant there as well.

Thanks
Jan
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
URL: <https://lists.fedorahosted.org/pipermail/sssd-devel/attachments/20111018/59301073/attachment.sig>


More information about the sssd-devel mailing list