Thanks for the tip on the sudo_provider setting.  I was trying to work out how to do that but couldn't find the exact option.

I managed to find the solution to my original problem through some trial and error.  Seems I needed to set "ldap_referrals = false" in my config.  Put that in and it all started and worked correctly.

Thanks,
Mark J


On 23 July 2018 at 18:20, Jakub Hrozek <jhrozek@redhat.com> wrote:


> On 23 Jul 2018, at 04:05, Mark Johnson <mark.johnson.iovox@gmail.com> wrote:
>
> I've been going around in circles with this for days and I'm stuck.  I'm trying to run up a new AD environment with only Samba 4.8.3 servers that we'll authenticate user server access against via SSSD/LDAP using a simple bind.  All of our servers are either CentOS 6 or 7.
>
> I've created a test environment with a single Samba AD 4.8.3 server as the AD server, a Windows 7 client to run RSAT and a CentOS 6 and CentOS 7 server to test user authentication.  The Samba server is up and running and I can manage the directory via RSAT.  I've set up the CentOS 6 server and can successfully authenticate user logins on this via using SSSD/LDAP to the AD.  However, the issue I have is with the CentOS 7 server.  I've basically copied the SSSD config from the CentOS 6 server so everything is the same.  However, when I start SSSD on the CentOS 7 server, it binds successfully and does an initial searchRequest which it gets a result from but after doing the subsequent searchRequests on Configuration, ForestDnsZones and DomainDnsZones I just see a RST from the server and the whole process starts over again.  Over the third failure, SSSD fails to start and stops trying.
>
> Comparing packet captures on the AD server when starting SSSD on both servers, the initial ROOT search request and response are identical as is the bind request and response.  However, the first wholeSubtree search request is where things start looking different.  On the CentOS 6 server, it shows a filter in the request of:
> Filter: (&(&(cn=smtp)(ipServiceProtocol=dccp))(objectclass=ipService))
> and there are 4 attributes in the request - objectClass, cn, ipServicePort, ipServiceProtocol
>
> Whereas on the CentOS 7 server, the filter looks like this:
> Filter: (&(objectClass=sudoRole)(|(|(|(|(|(|(|(|(|(!(sudoHost=*))(sudoHost=ALL))(sudoHost=ldaptest7.company.com))(sudoHost=ldaptest7))(sudoHost=192.168.193.62))(sudoHost=192.168.192.0/23))(sudoHost=fe80::5054:ff:fef2:26ed))(sudoHost=fe80::/6
> with 13 attributes - objectClass, cn, and a bunch of sudo attributes.
>
> The response from the Samba server to each of these is nearly identical.  Both servers then send searchRequests for Configuration, ForestDnsZones and DomainDnsZones but with the same filter differences above.  This is the point of failure for the CentOS 7 server.  The other server gets a successful response from the Samba server, but the CentOS 7 server just gets an ACK.  When I up the debug level on SSSD on the CentOS 7 server, I see a few different errors but I'm not sure which of these show cause or effect.  Examples...
>
> (Thu Jul 19 23:40:34 2018) [sssd[be[AD.COMPANY.COM]]] [common_parse_search_base] (0x0100): Search base added: [SUDO][dc=ad,dc=company,dc=com][SUBTREE][]
> (Thu Jul 19 23:40:34 2018) [sssd[be[AD.COMPANY.COM]]] [common_parse_search_base] (0x0100): Search base added: [AUTOFS][dc=ad,dc=company,dc=com][SUBTREE][]
> (Thu Jul 19 23:40:34 2018) [sssd[be[AD.COMPANY.COM]]] [dp_client_register] (0x0100): Cancel DP ID timeout [0x55941e9a6860]
> (Thu Jul 19 23:40:34 2018) [sssd[be[AD.COMPANY.COM]]] [dp_find_method] (0x0100): Target [subdomains] is not initialized
> (Thu Jul 19 23:40:34 2018) [sssd[be[AD.COMPANY.COM]]] [dp_req_reply_gen_error] (0x0080): DP Request [Subdomains #0]: Finished. Target is not supported with this configuration.
>
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [fo_resolve_service_send] (0x0100): Trying to resolve service 'LDAP'
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [set_server_common_status] (0x0100): Marking server '192.168.192.50' as 'resolving name'
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [set_server_common_status] (0x0100): Marking server '192.168.192.50' as 'name resolved'
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [sdap_get_server_opts_from_rootdse] (0x0100): Setting AD compatibility level to [4]
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [sdap_cli_auth_step] (0x0100): expire timeout is 900
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [simple_bind_send] (0x0100): Executing simple bind as: sssd@ad.company.com
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [fo_set_port_status] (0x0100): Marking port 389 of server '192.168.192.50' as 'working'
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [set_server_common_status] (0x0100): Marking server '192.168.192.50' as 'working'
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [be_run_online_cb] (0x0080): Going online. Running callbacks.
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [be_ptask_enable] (0x0080): Task [SUDO Smart Refresh]: already enabled
> (Thu Jul 19 23:40:44 2018) [sssd[be[AD.COMPANY.COM]]] [sdap_process_result] (0x0040): ldap_result error: [Can't contact LDAP server]

hmm, I don’t know why would libldap return ‘Can’t contact LDAP server here..”

> sssd_be: io.c:224: ber_flush2: Assertion `( (sb)->sb_opts.lbo_valid == 0x3 )' failed.

moreover there is some assertion in the lber code..

> (Thu Jul 19 23:40:44 2018) [sssd] [svc_child_info] (0x0040): Child [1570] terminated with signal [6]
>

..which causes the sssd_be process to SIGABRT.
I’ve never seen this issue before..

> I get the feeling that the issue is around sudo somehow, but I don't believe I have sudo enabled in my sssd. 
>

So one thing that changed between 6 and 7 is that unless you explicitly disable the sudo provider it is always ran. So one thing to check might be to explicitly set “sudo_provider=none” in the config file..

> Here's my sssd.conf from the CentOS 7 server:
>
> [sssd]
> config_file_version = 2
> reconnection_retries = 3
> sbus_timeout = 30
> services = nss, pam
> domains = AD.COMPANY.COM
>
> [nss]
> filter_groups = root,bin,daemon,sys,adm,tty,disk,lp,mem,kmem,wheel,mail,uucp,man,games,gopher,video,dip,ftp,lock,audio,nobody,users,floppy,vcsa,utmp,utempter,rpc,cdrom,tape,dialout,rpcuser,nfsnobody,sshd,cgred,screen,saslauth,apache,mailnull,smmsp,mysql
> filter_users = root,bin,daemon,adm,lp,sync,shutdown,halt,mail,uucp,operator,games,gopher,ftp,nobody,vcsa,rpc,rpcuser,nfsnobody,sshd,saslauth,apache,mailnull,smmsp,mysql,apache
> reconnection_retries = 3
> #entry_cache_timeout = 300
> entry_cache_nowait_percentage = 75
>
> [domain/AD.COMPANY.COM]
> enumerate = false
> cache_credentials = true
>
> id_provider = ldap
> #auth_provider = ldap
>
> ldap_schema = rfc2307bis
> ldap_user_principal = userPrincipalName
> ldap_user_fullname = displayName
> ldap_user_name = sAMAccountName
> ldap_user_object_class = user
> ldap_user_home_directory = unixHomeDirectory
> ldap_user_shell = loginShell
> ldap_group_object_class = group
> ldap_force_upper_case_realm = True
>
> ldap_uri = ldap://192.168.192.50
>
> ldap_search_base = dc=ad,dc=company,dc=com
> ldap_id_use_start_tls = false
> ldap_tls_reqcert = never
> ldap_tls_cacert = /etc/sssd/ca.company.com.crt
>
> access_provider = ldap
> ldap_access_filter = memberOf=cn=ServerAdmins,ou=Groups,dc=ad,dc=company,dc=com
>
> ldap_default_authtok_type = password
> ldap_default_bind_dn = sssd@ad.company.com
> ldap_default_authtok = Password1
>
>
> [pam]
>
>
>
> I tried adding the sudo roles schema to active directory to see if it would resolve the sssd not starting issue, but while I was able to successfully import the schema via ldifde and create the sudoers OU in the root, but when it came to adding the sudoRole object via ADSIEdit, I got an Operation Failed error - "An invalid directory pathname was passed".  So, I'm not sure if adding this will resolve the issue or not.
>
> There was no sudoers entry in nsswitch.conf so I tried specifically adding the following line to explicitly omit sss in case it has become a default setting:
>
> sudoers:    files
>
> But that made no difference.
>
> I've tried all of the above twice from scratch to be sure and I got the same results both times.  I can successfully query the directory via the same ldapsearch command from both CentOS servers.  I don't know if I'm completely barking up the wrong tree.  I'm just going around in circles now and I can't think of anything new to try.  Oh, and here's my smb.conf...
>
> # Global parameters
> [global]
>     bind interfaces only = Yes
>     dns forwarder = 192.168.192.1
>     interfaces = lo eth0
>     netbios name = TUG-SAMBA
>     realm = AD.COMPANY.COM
>     server role = active directory domain controller
>     workgroup = COMPANY
>     idmap_ldb:use rfc2307 = yes
>     dsdb:schema update allowed = yes
>     ldap server require strong auth = no
>
> [netlogon]
>     path = /var/lib/samba/sysvol/ad.company.com/scripts
>     read only = No
>
> [sysvol]
>     path = /var/lib/samba/sysvol
>     read only = No
>
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