Samba 4.9 Features added/changed

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Samba 4.9.0rc1

Release Notes for Samba 4.9.0rc1
July 13, 2018

Release Announcements

This is the first release candidate of Samba 4.9. This is *not* intended for production environments and is designed for testing purposes only. Please report any defects via the Samba bug reporting system at https://bugzilla.samba.org/.

Samba 4.9 will be the next version of the Samba suite.


UPGRADING

NEW FEATURES/CHANGES

net ads setspn

There is a new 'net ads setspn' sub command for managing Windows SPN(s) on the AD. This command aims to give the basic functionality that is provided on windows by 'setspn.exe' e.g. ability to add, delete and list Windows SPN(s) stored in a Windows AD Computer object.

The format of the command is:

net ads setspn list [machine]
net ads setspn [add | delete ] SPN [machine]

'machine' is the name of the computer account on the AD that is to be managed. If 'machine' is not specified the name of the 'client' running the command is used instead.

The format of a Windows SPN is

 'serviceclass/host:port/servicename' (servicename and port are optional)

serviceclass/host is generally sufficient to specify a host based service.

net ads keytab changes

net ads keytab add no longer attempts to convert the passed serviceclass (e.g. nfs, html etc.) into a Windows SPN which is added to the Windows AD computer object. By default just the keytab file is modified.

A new keytab subcommand 'add_update_ads' has been added to preserve the legacy behaviour. However the new 'net ads setspn add' subcommand should really be used instead.

net ads keytab create no longer tries to generate SPN(s) from existing entries in a keytab file. If it is required to add Windows SPN(s) then 'net ads setspn add' should be used instead.

Local authorization plugin for MIT Kerberos

This plugin controls the relationship between Kerberos principals and AD accounts through winbind. The module receives the Kerberos principal and the local account name as inputs and can then check if they match. This can resolve issues with canonicalized names returned by Kerberos within AD. If the user tries to log in as 'alice', but the samAccountName is set to ALICE (uppercase), Kerberos would return ALICE as the username. Kerberos would not be able to map 'alice' to 'ALICE' in this case and auth would fail. With this plugin account names can be correctly mapped. This only applies to GSSAPI authentication, not for the getting the initial ticket granting ticket.

VFS audit modules

The vfs_full_audit module has changed it's default set of monitored successful and failed operations from "all" to "none". That helps to prevent potential denial of service caused by simple addition of the module to the VFS objects.

Also, modules vfs_audit, vfs_ext_audit and vfs_full_audit now accept any valid syslog(3) facility, in accordance with the manual page.

Database audit support

Changes to the Samba AD's sam.ldb database are now logged to Samba's debug log under the "dsdb_audit" debug class and "dsdb_json_audit" for JSON formatted log entries.

Transaction commits and roll backs are now logged to Samba's debug logs under the "dsdb_transaction_audit" debug class and "dsdb_transaction_json_audit" for JSON formatted log entries.

Password change audit support

Password changes in the AD DC are now logged to Samba's debug logs under the "dsdb_password_audit" debug class and "dsdb_password_json_audit" for JSON formatted log entries.

Group membership change audit support

Group membership changes on the AD DC are now logged to Samba's debug log under the "dsdb_group_audit" debug class and "dsdb_group_json_audit" for JSON formatted log entries.

Log Authentication duration

For NTLM and Kerberos KDC authentication, the authentication duration is now logged. Note that the duration is only included in the JSON formatted log entries.

JSON library Jansson required for the AD DC

By default the Jansson JSON library is required for Samba to build. It is strictly required for the Samba AD DC, and is optional for builds --without-ad-dc by specifying --without-json-audit at configure time.

New Experimental LMDB LDB backend

A new experimental LDB backend using LMDB is now available. This allows databases larger than 4Gb (Currently the limit is set to 6Gb, but this will be increased in a future release). To enable lmdb, provision or join a domain using the --backend-store=mdb option.

This requires that a version of lmdb greater than 0.9.16 is installed and that samba has not been built with the --without-ldb-lmdb option.

Please note this is an experimental feature and is not recommended for production deployments.

Password Settings Objects

Support has been added for Password Settings Objects (PSOs). This AD feature is also known as Fine-Grained Password Policies (FGPP).

PSOs allow AD administrators to override the domain password policy settings for specific users, or groups of users. For example, PSOs can force certain users to have longer password lengths, or relax the complexity constraints for other users, and so on. PSOs can be applied to groups or to individual users. When multiple PSOs apply to the same user, essentially the PSO with the best precedence takes effect.

PSOs can be configured and applied to users/groups using the 'samba-tool domain passwordsettings pso' set of commands.

Domain backup and restore

A new samba-tool command has been added that allows administrators to create a backup-file of their domain DB. In the event of a catastrophic failure of the domain, this backup-file can be used to restore Samba services.

The new 'samba-tool domain backup online' command takes a snapshot of the domain DB from a given DC. In the event of a catastrophic DB failure, all DCs in the domain should be taken offline, and the backup-file can then be used to recreate a fresh new DC, using the 'samba-tool domain backup restore' command. Once the backed-up domain DB has been restored on the new DC, other DCs can then subsequently be joined to the new DC, in order to repopulate the Samba network.

Domain rename tool

Basic support has been added for renaming a Samba domain. The rename feature is designed for the following cases:

  1. Running a temporary alternate domain, in the event of a catastrophic failure of the regular domain. Using a completely different domain name and realm means that the original domain and the renamed domain can both run at the same time, without interfering with each other. This is an advantage over creating a regular 'online' backup - it means the renamed/alternate domain can provide core Samba network services, while trouble-shooting the fault on the original domain can be done in parallel.
  2. Creating a realistic lab domain or pre-production domain for testing.

Note that the renamed tool is currently not intended to support a long-term rename of the production domain. Currently renaming the GPOs is not supported and would need to be done manually.

The domain rename is done in two steps:

first, the 'samba-tool domain backup rename' command will clone the domain DB, renaming it in the process, and producing a backup-file.
Then, the 'samba-tool domain backup restore' command takes the backup-file and restores the renamed DB to disk on a fresh DC.

New samba-tool options for diagnosing DRS replication issues

The 'samba-tool drs showrepl' command has two new options controlling the output. With --summary, the command says very little when DRS replication is working well. With --json, JSON is produced. These options are intended for human and machine audiences, respectively.

The 'samba-tool visualize uptodateness' visualizes replication lag as a heat-map matrix based on the DRS uptodateness vectors. This will show you if (but not why) changes are failing to replicate to some DCs.

Automatic site coverage and GetDCName improvements

Samba's AD DC now automatically claims otherwise empty sites based on which DC is the nearest in the replication topology.

This, combined with efforts to correctly identify the client side in the GetDCName Netlogon call will improve service to sites without a local DC.

Improved samba-tool computer command

The 'samba-tool computer' command allow manipulation of computer accounts including creating a new computer and resetting the password. This allows an 'offline join' of a member server or workstation to the Samba AD domain.

Samba performance tool now operates against Microsoft Windows AD

The Samba AD performance testing tool traffic_reply can now operate against a Windows based AD domain. Previously it only operated correctly against Samba.

DNS entries are now cleaned up during DC demote

DNS records are now cleaned up as part of the 'samba-tool domain demote' including both the default and --remove-other-dead-server modes.

Additionally DNS records can be automatically cleaned up for a given name with the 'samba-tool dns cleanup' command, which aids in cleaning up partially removed DCs.

samba-tool ntacl sysvolreset is now much faster

The 'samba-tool ntacl sysvolreset' command, used on the Samba AD DC, is now much faster than in previous versions, after an internal rework.

Samba now tested with CI GitLab

Samba developers now have pre-commit testing available in GitLab, giving reviewers confidence that the submitted patches pass a full CI before being submitted to the Samba Team's own autobuild system.

Dynamic DNS record scavenging support

It is now possible to enable scavenging of DNS Zones to remove DNS records that were dynamically created and have not been touched in some time.

This support should however only be enabled on new zones or new installations. Sadly old Samba versions suffer from BUG 12451 and mark dynamic DNS records as static and static records as dynamic. While a dbcheck rule may be able to find these in the future, currently a reliable test has not been devised.

Finally, there is not currently a command-line tool to enable this feature, currently it should be enabled from the DNS Manager tool from Windows. Also the feature needs to have been enabled by setting the smb.conf parameter "dns zone scavenging = yes".

CTDB changes

There are many changes to CTDB in this release.

  • Configuration has been completely overhauled
  • Daemon and tool options are now specified in a new ctdb.conf Samba-style configuration file. See ctdb.conf(5) for details.
  • Event script configuration is no longer specified in the top-level configuration file. It can now be specified per event script. For example, configuration options for the 50.samba event script can be placed alongside the event script in a file called 50.samba.options. Script options can also be specified in a new script.options file. See ctdb-script.options(5) for details.
  • Options that affect CTDB startup should be configured in the distribution-specific configuration file. See ctdb.sysconfig(5) for details.
  • Tunable settings are now loaded from ctdb.tunables. Using CTDB_SET_TunableVariable=<value> in the main configuration file is no longer supported. See ctdb-tunables(7) for details.
A script to convert an old-style configuration to a new one will be available for release but is not yet available.
  • The following configuration variables and corresponding ctdbd command-line options have been removed and not replaced with counterparts in the new configuration scheme:
   CTDB_PIDFILE                     --pidfile
   CTDB_SOCKET			     --socket
   CTDB_NODES			     --nlist
   CTDB_PUBLIC_ADDRESSES	     --public-addresses
   CTDB_EVENT_SCRIPT_DIR	     --event-script-dir
   CTDB_NOTIFY_SCRIPT		     --notification-script
   CTDB_PUBLIC_INTERFACE	     --public-interface
   CTDB_MAX_PERSISTENT_CHECK_ERRORS --max-persistent-check-errors
  • ify.d/ subdirectory of the configuration directory are now run by unconditionally.
  • Interfaces for public IP addresses must always be specified in the
public_addresses file using the currently supported format.
Some related items that have been removed are:
  • The ctdb command's --socket command-line option
  • The ctdb command's CTDB_NODES environment variable
When writing tests there are still mechanisms available to change the locations of certain directories and files.
  • Event scripts have moved to the scripts/legacy subdirectory of the configuration directory
Event scripts must now end with a ".script" suffix.
  • The following service-related event script options have been removed:
   CTDB_MANAGES_SAMBA
   CTDB_MANAGES_WINBIND
   CTDB_MANAGES_CLAMD
   CTDB_MANAGES_HTTPD
   CTDB_MANAGES_ISCSI
   CTDB_MANAGES_NFS
   CTDB_MANAGES_VSFTPD
   CTDB_MANAGED_SERVICES
Event scripts for services are now disabled by default. To enable an event script and, therefore, manage a service use a command like the following:
   ctdb event script enable legacy 50.samba
  • Notification scripts have moved to the scripts/notification subdirectory of the configuration directory
Notification scripts must now end with a ".script" suffix.
  • Support for setting CTDB_DBDIR=tmpfs has been removed
This feature has not been implemented in the new configuration system. If this is desired then a tmpfs filesystem should be manually mounted on the directory pointed to by the "volatile database directory" option. See ctdb.conf(5) for more details.
  • Support for the NoIPHostOnAllDisabled tunable has been removed
If all nodes are unhealthy or disabled then CTDB will not host public IP addresses. That is, CTDB now behaves as if NoIPHostOnAllDisabled were set to 1.
  • The onnode command's CTDB_NODES_FILE environment variable has been removed
The -f option can still be used to specify an alternate node file.
  • The 10.external event script has been removed
  • The CTDB_SHUTDOWN_TIMEOUT configuration variable has been removed
As with other daemons, if ctdbd does not shut down when requested then manual intervention is required. There is no safe way of automatically killing ctdbd after a failed shutdown.
  • CTDB_SUPPRESS_COREFILE and CTDB_MAX_OPEN_FILES configuration variable have been removed
These should be setup in the systemd unit/system file or, for SYSV init, in the distribution-specific configuration file for the ctdb service.
  • CTDB_PARTIALLY_ONLINE_INTERFACES incompatibility no longer enforced
11.natgw and 91.lvs will no longer fail if CTDB_PARTIALLY_ONLINE_INTERFACES=yes. The incompatibility is, however, well documented. This option will be removed in future and replaced by sensible behaviour where public IP addresses simply switch interfaces or become unavailable when interfaces are down.
  • Configuration file /etc/ctdb/sysconfig/ctdb is no longer supported

GPO Improvements

The samba_gpoupdate command (used in applying Group Policies to the samba machine itself) has been renamed to samba_gpupdate and had the syntax changed to better match the same tool on Windows.

REMOVED FEATURES

smb.conf changes

As the most popular Samba install platforms (Linux and FreeBSD) both support extended attributes by default, the parameters "map readonly", "store dos attributes" and "ea support" have had their defaults changed to allow better Windows fileserver compatibility in a default install.

 Parameter Name                     Description             Default
 --------------                     -----------             -------
 map readonly                       Default changed              no
 store dos attributes               Default changed             yes
 ea support                         Default changed             yes
 full_audit:success                 Default changed            none
 full_audit:failure                 Default changed            none

VFS interface changes

The VFS ABI interface version has changed to 39. Function changes are:

SMB_VFS_FSYNC: Removed: Only async versions are used.
SMB_VFS_READ: Removed: Only PREAD or async versions are used.
SMB_VFS_WRITE: Removed: Only PWRITE or async versions are used.
SMB_VFS_CHMOD_ACL: Removed: Only CHMOD is used.
SMB_VFS_FCHMOD_ACL: Removed: Only FCHMOD is used.

Any external VFS modules will need to be updated to match these changes in order to work with 4.9.x.

KNOWN ISSUES

Release_Planning_for_Samba_4.9#Release_blocking_bugs

 https://download.samba.org/pub/samba/rc/samba-4.9.0rc1.WHATSNEW.txt