Speaker Andrew Bartlett
Time 2009-09-19 09:30
Conference LCA2009

Samba4 is:

  • replacement for Active Directory.
  • move Samba beyond NT4 style domains which are obsolete.
  • LDAP, Kerberos, DNS
  • A provide a way to move forward without locking in to Microsoft products.

Features:

  • Samba has reputation of being difficult to configure. Samba4 should just work out of the box.
  • Automatically generate configuration required for OpenLDAP, Bind, etc.
  • Multi-master replication with OpenLDAP. Samba4 no longer a single server solution. No longer single point of failure.
  • Scripting language == Python
  • Smart card support.
  • NTP signing support - patch to ntpd server. Required for secure Kerberos authentication. Microsoft’s own NTP signing standard, not the existing standard. Doesn’t use network byte order.
  • Group Policy support.
    • Basically dump. Client driven. Stored as globs. Registry files on filesystem. Samba begginning to understand format for reading and dumping values. Should be able to track changes.

Autoconfiguration:

  • OpenLDAP not used directly by clients, generally doesn’t listen on standard port; clients generally don’t connect to it.
  • OpenLDAP modules to keep different methods of specifying groups in sync.
  • ActiveDirectory schema different, this is automatically generated.

Development

  • Needs sysadmins/programmers for testing, etc.
  • More code being written in Python.
  • Multimaster currently difficult to setup - this is being made easier.
  • “PAC Validation failed”
    • PAC == Privilage Attribute Certificate
    • Windows XP must check PAC with KDC, but only rarely.
  • Microsoft’s AD schema.
    • Not quite LDIF format.
    • Syntax errors.
    • Results to be integrated.
  • Account expiry
    • Hardcoded 28 day password expiry
    • Also ignored no expiry flag.
  • Machines stop working after one month.
    • Restore password from backup, and it worked.
    • Spent 1 week at Microsoft to figure it out.
    • Once a week each Windows client would change password to random value.
    • This string could not be interpreted as a UTF-8 string, as these were not valid characters.
    • Samba substituted empty string instead, possibly not a good idea.
    • Solution ugly. Reduces entropy? Maybe. May not be forward compatable with future UTF-8 specifications.
    • Each client needs to have a list of invalid characters and treat string as a string only if it doesn’t contain invalid characters.
  • MS-SNTP - Microsoft’s signing NTP protocol. NTP community not happy… Will be integrated upstream but disabled by default.
  • Web interface needs more work.
  • Own LDAP server with its own schema. Is this a problem?

Future:

  • Domain trusts
    • Limited success.
  • Replication
    • Migration process.
    • Once only copy.
    • Full read/write replication.
  • Want to know why people can’t switch to Samba 4.
  • Don’t yet implement all the things Samba 3 does.
    • Print server. Getting correct drivers is a big part of the problem.
    • VFS modules in Samba 3 might be more trusted.
  • Upgrade process.

Questions

Revision control file system?

  • Snapshots an be handled.
  • Full revision control filesystems, should be possible to expose history of changes to clients.

python-wmi forked from early development version of Samba4, without coordination with Samba team, and needs to be reintegrated with Samba4 again.

LDAP - Samba provides its own LDAP server, which can write to/from a file or talk to an OpenLDAP server.