[SSSD] [PATCH] Global Catalog lookups and Active Directory trusted domains

Jakub Hrozek jhrozek at redhat.com
Wed Jun 5 09:32:39 UTC 2013


On Wed, Jun 05, 2013 at 11:26:28AM +0200, Lukas Slebodnik wrote:
> On (05/06/13 10:31), Sumit Bose wrote:
> >On Wed, Jun 05, 2013 at 09:51:04AM +0200, Lukas Slebodnik wrote:
> >> On (04/06/13 22:37), Jakub Hrozek wrote:
> >> >On Tue, Jun 04, 2013 at 08:46:44PM +0200, Sumit Bose wrote:
> >> >> On Tue, Jun 04, 2013 at 03:25:12PM +0200, Jakub Hrozek wrote:
> >> >> > On Mon, Jun 03, 2013 at 11:58:02AM +0200, Jakub Hrozek wrote:
> >> >> > > On Fri, May 31, 2013 at 04:01:51PM +0200, Jakub Hrozek wrote:
> >> >> > > > On Fri, May 31, 2013 at 03:47:32PM +0200, Jakub Hrozek wrote:
> >> >> > > > > On Fri, May 31, 2013 at 10:59:21AM +0200, Lukas Slebodnik wrote:
> >> >> > > > > > On (29/05/13 18:39), Jakub Hrozek wrote:
> >> >> > > > > > >Hi,
> >> >> > > > > > >
> >> >> > > > > > >the attached patches implement lookups in Global Catalog and AD
> >> >> > > > > > >subdomains. Unfortunately they turned out to be quite complex and I'd like
> >> >> > > > > > >to make them shorter and remove some of the complexity during the review
> >> >> > > > > > >if possible.
> >> >> > > > > > >
> >> >> > > > > > >The patches implement identity lookups, authentication. There will be
> >> >> > > > > > >additional patch that implements SRV discovery, but I wanted to get
> >> >> > > > > > >the patches reviewed so that I don't waste time if the approach was not
> >> >> > > > > > >correct. Authentication currently requires the subdomain to be present in
> >> >> > > > > > >krb5.conf otherwise the Kerberos libraries would search for _kerberos-master,
> >> >> > > > > > >not _kerberos and fail. Sumit, who kindly helped me debug this problem
> >> >> > > > > > >might already have a MIT bug handy.
> >> >> > > > > > >
> >> >> > > > > > >There is couple of LDAP provider patches that instead of using a single
> >> >> > > > > > >connection towards LDAP allows for a linked list in the sdap_id_ctx.
> >> >> > > > > > >Then the caller of the LDAP ID function can choose himself what
> >> >> > > > > > >connection he would like to use for the particular lookup. For instance,
> >> >> > > > > > >for trusted AD users, GC lookups are always used, but for native AD
> >> >> > > > > > >users, LDAP can be used (and is actually preferred).
> >> >> > > > > > >
> >> >> > > > > > >One part of the complexity comes from the fact that initially I wanted
> >> >> > > > > > >the ID code to be flexible and allow "failover" between the connection.
> >> >> > > > > > >In other words, the ID code could try GC lookup first and optionally
> >> >> > > > > > >fail over to LDAP lookup using the same context if the entry was not
> >> >> > > > > > >found using the first connection. 
> >> >> > > > > > >
> >> >> > > > > > >But after testing the identities I'm not sure if that is actually needed. The
> >> >> > > > > > >trusted users and groups have to be looked up from GC anyway and the local
> >> >> > > > > > >users and groups would be available in LDAP. Maybe we could conserve
> >> >> > > > > > >some resources by attempting to look up local users from GC and only
> >> >> > > > > > >keep one connection open when possible, but I'm not quite sure it is
> >> >> > > > > > >worth it. Removing the connection failover would get rid of having to
> >> >> > > > > > >report the LDAP return code to AD identity functions and maybe we could
> >> >> > > > > > >even tie the connection with sdap_domain, too.
> >> >> > > > > > >
> >> >> > > > > > >So can anyone think of a lookup where we would like to try one
> >> >> > > > > > >connection and then the other? Maybe groups that contain members from
> >> >> > > > > > >both primary and trusted domains might be such a case, but there we
> >> >> > > > > > >could handle the failover in the group request.
> >> >> > > > > > >
> >> >> > > > > > >[PATCH 01/15] Do not obfuscate calls with booleans
> >> >> > > > > > >This is purely a personal preference, but I found it hard to follow what
> >> >> > > > > > >the various booleans meant when reading function calls. Maybe macros
> >> >> > > > > > >would make the code more readable, but I'm OK with not applying this
> >> >> > > > > > >patch if others disagree.
> >> >> > > > > > >
> >> >> > > > > > >
> >> >> > > > > > >
> >> >> > > > > > >[PATCH 02/15] LDAP: sdap_id_ctx might contain several connections
> >> >> > > > > > >With some LDAP server implementations, one server might provide different
> >> >> > > > > > >"views" of the identites on different ports. One example is the Active
> >> >> > > > > > >Directory Global catalog. The provider would contact different view
> >> >> > > > > > >depending on which operation it is performing and against which SSSD domain.
> >> >> > > > > > >
> >> >> > > > > > >At the same time, these views run on the same server, which means the same
> >> >> > > > > > >server options, enumeration, cleanup or Kerberos service should be used.
> >> >> > > > > > >So instead of using several different failover ports or several instances
> >> >> > > > > > >of sdap_id_ctx, this patch introduces a new "struct sdap_id_conn_ctx" that
> >> >> > > > > > >contains the connection cache to the particular view and an instance of
> >> >> > > > > > >"struct sdap_options" that contains the URI.
> >> >> > > > > > >
> >> >> > > > > > >No functional changes are present in this patch, currently all providers
> >> >> > > > > > >use a single connection. Multiple connections will be used later in the
> >> >> > > > > > >upcoming patches.
> >> >> > > > > > >
> >> >> > > > > > >
> >> >> > > > > > >
> >> >> > > > > > 
> >> >> > > > > > src/providers/ldap/ldap_init.c: In function 'sssm_ldap_id_init':
> >> >> > > > > > src/providers/ldap/ldap_init.c:188:21: warning: 'ctx' may be used uninitialized in this function [-Wmaybe-uninitialized]
> >> >> > > > > > 
> >> >> > > > > > >[PATCH 03/15] LDAP: Refactor account info handler into a tevent request
> >> >> > > > > > >The sdap account handler was a function with its own private callback
> >> >> > > > > > >that directly called the back end handlers. This patch refactors the
> >> >> > > > > > >handler into a new tevent request that the current sdap handler calls.
> >> >> > > > > > >
> >> >> > > > > > >This refactoring would allow the caller to specify a custom sdap
> >> >> > > > > > >connection for use by the handler and optionally retry the same request
> >> >> > > > > > >with another connection inside a single per-provider handler.
> >> >> > > > > > >
> >> >> > > > > > >No functional changes are present in this patch.
> >> >> > > > > > >
> >> >> > > > > > 
> >> >> > > > > > src/providers/ldap/ldap_id.c: In function 'sdap_handle_acct_req_done':
> >> >> > > > > > src/providers/ldap/ldap_id.c:1206:9: error: implicit declaration of function 'sdap_get_user_and_group_recv' [-Werror=implicit-function-declaration]
> >> >> > > > > 
> >> >> > > > > [snip]
> >> >> > > > > 
> >> >> > > > > Thank you I will work on a respin, but it should be noted that these
> >> >> > > > > warnings and even errors occur only when compiling patches individually.
> >> >> > > > > Applying the whole set would make the patches compilable and testable.
> >> >> > > > 
> >> >> > > > Attached are rebased patches on top of the current master. I will work
> >> >> > > > on making the patches compilable individually but the attached gzipped
> >> >> > > > patches should unblock the review now.
> >> >> > > 
> >> >> > > Attached is another rebase on top of the current master. I also
> >> >> > > confirmed that using krb5-libs-1.11.2-10.fc19.x86_64 I no longer needed
> >> >> > > to define the subdomain's master_kdc in krb5.conf.
> >> >> > 
> >> >> > Attached is the same set of patches, just fixed to address Lukas'
> >> >> > comments. The patches can now be compiled separately.
> >> >> 
> >> >> did you attach the right tar ball?
> >> >
> >> >Not sure, I thought I did.
> >> >
> >> >> I still can see the two issues in
> >> >> ldap_id?
> >> >> 
> >> >
> >> >I fixed one -Wmaybe-uninitialized warning, do you see some other?
> >> >
> >> >I pushed the latest patches into my fedorapeople.org branch:
> >> >git://fedorapeople.org/home/fedora/jhrozek/public_git/sssd.git
> >> >
> >> >The branch is called "gc". A tarball is also attached to be able to
> >> >access the archived versions of work-in-progress.
> >> 
> >> I wrote it in my previous mail. There is one error, even in your branch
> >> from fedorapeople git repo.
> >> 
> >> src/providers/ldap/ldap_id.c: In function 'sdap_handle_acct_req_done':
> >> src/providers/ldap/ldap_id.c:1280:9: error: implicit declaration of function 'sdap_get_user_and_group_recv' [-Werror=implicit-function-declaration]
> >> cc1: some warnings being treated as errors
> >> 
> >> Solution is very simple and I don't think it is stop-blocker for review
> >> process.
> It seems that problem is with fedora 19 (gcc, libtool or ...)
> I tried to recompile srpm in mock.
> mock --root fedora-19-x86_64 --rebuild --resultdir f19/ sssd-1.9.93-0.20130605.1034.gitd09ea20.fc18.src.rpm
> And packages were built successfully.
> 
> But in fedora 18 process failed.

I don't want to block review trying to find a toolchain bug, so I
recompiled the tree with clang which showed both the implicit
declaration and the warnings.

I pushed the code into my gc branch and I'm attaching an updated tarball
again. Sorry for the confusion, I only developed and tested on F19.
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