ad: fallback to ldap if cldap is not available in libldap

[pbrezina]

Some distributions do not have cldap support available in libldap. Now
we fallback to ad ping over ldap conditionally during build time.

Resolves: #5720

:fixes: AD ping is now sent over `ldap` if `cldap` support is not available
  during build. This helps to build SSSD on distributions without `cldap`
  support in `libldap`.

[justin-stephenson]

Hi, I compiled openldap-2.5.6 without CLDAP support on fedora rawhide.

• Before the PR:

(2021-08-17 14:25:02): [be[ad.vm]] [ad_cldap_ping_send] (0x0400): Sending CLDAP ping
(2021-08-17 14:25:02): [be[ad.vm]] [ad_cldap_ping_domain_discovery_done] (0x0400): Found 1 domain controllers in domain ad.vm
(2021-08-17 14:25:02): [be[ad.vm]] [sdap_connect_host_resolv_done] (0x0400): Connecting to cldap://root-dc.ad.vm:389
(2021-08-17 14:25:02): [be[ad.vm]] [sss_ldap_init_sys_connect_done] (0x0020): ldap_init_fd failed: Bad parameter to an ldap routine. [22][cldap://root-dc.ad.vm:389]
(2021-08-17 14:25:02): [be[ad.vm]] [ad_cldap_ping_done] (0x0040): Unable to get site and forest information [2]: No such file or directory

• After the PR:

[root@master.client.vm ~]# egrep -irn 'sdap_connect_host_send|cldap' /var/log/sssd/sssd_ad.vm.log 
457:(2021-08-17 15:02:17): [be[ad.vm]] [ad_cldap_ping_send] (0x0400): Sending CLDAP ping
477:(2021-08-17 15:02:17): [be[ad.vm]] [ad_cldap_ping_domain_discovery_done] (0x0400): Found 1 domain controllers in domain ad.vm
478:(2021-08-17 15:02:17): [be[ad.vm]] [sdap_connect_host_send] (0x0400): Resolving host root-dc.ad.vm
506:(2021-08-17 15:02:17): [be[ad.vm]] [ad_cldap_ping_dc_done] (0x0400): root-dc.ad.vm:389: found site (Default-First-Site-Name) and forest (ad.vm)
507:(2021-08-17 15:02:17): [be[ad.vm]] [ad_cldap_ping_done] (0x0400): Found site: Default-First-Site-Name
508:(2021-08-17 15:02:17): [be[ad.vm]] [ad_cldap_ping_done] (0x0400): Found forest: ad.vm
1330:(2021-08-17 15:02:31): [be[ad.vm]] [ad_cldap_ping_send] (0x0400): [RID#6] CLDAP ping is not necessary, using site 'Default-First-Site-Name' and forest 'ad.vm'

The only issue I see is that the 'CLDAP' ping log messages are misleading (ldap ping instead). The function names also, but changing those is not worth it IMO (too invasive for this).

I'm not sure if it should block the PR but It would also be helpful if one of the users reporting this issue could test out the patch.

[sven-probst]

Applying this patch to the debian bullseye package src fixes the problem with sssd/ad-group lookups.

[pbrezina]

Thanks. @justin-stephenson We can't change name of the functions, perhaps we could change CLDAP -> LDAP in debug messages but I don't think its worth it as well. Are you going to ack this,

[justin-stephenson]

Ack from my side.

[pbrezina]

Pushed PR: #5743

• master
  • dfb6594 - ad: fallback to ldap if cldap is not available in libldap