Bug 15661 - Online backup fails when smb over tcp is missing
Summary: Online backup fails when smb over tcp is missing
Status: NEW
Alias: None
Product: Samba 4.1 and newer
Classification: Unclassified
Component: Python (show other bugs)
Version: 4.20.1
Hardware: All All
: P5 minor (vote)
Target Milestone: ---
Assignee: Douglas Bagnall
QA Contact: Samba QA Contact
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-10 20:12 UTC by Thomas Karlsson
Modified: 2024-07-05 17:25 UTC (History)
1 user (show)

See Also:

Attachments
Patch to ignore sysvol backup when smb is not running (991 bytes, patch)
2024-06-13 17:48 UTC, Thomas Karlsson 		no flags Details
Patch to enable a new option --no-sysvol for backup (2.15 KB, patch)
2024-07-05 17:25 UTC, Thomas Karlsson 		no flags Details
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Thomas Karlsson 2024-06-10 20:12:56 UTC 
If SMB over tcp is not running (port 445), then samba-tool domain backup online --server localhost --targetdir=backup will fail with an exception.

It crashes when trying to backup the sysvol.
My suggestion is to add a try and except block on line 278 to catch the exception.

I can provide a patch file, or make a pull request. If you want.
Comment 1 Douglas Bagnall 2024-06-11 22:03:44 UTC 
> I can provide a patch file, or make a pull request. If you want.

A patch is good. It would also be good to see the traceback.
Comment 2 Thomas Karlsson 2024-06-13 17:48:28 UTC 
Created attachment 18339 [details]
Patch to ignore sysvol backup when smb is not running

Adding a try and except when trying to connect to smb share sysvol.
Comment 3 Thomas Karlsson 2024-06-13 17:57:41 UTC 
Here is the exception.
Note that the exception comes from another version of Samba, I think 4.13.x, but it is still the same problem in the latest version.


Connecting to 192.168.10.1 at port 445
ERROR(runtime): uncaught exception - (3221226038, 'The transport-connection attempt was refused by the remote system.')
  File "/usr/lib/python3/dist-packages/samba/netcmd/__init__.py, line 186, in _run
    return self.run(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/samba/netcmd/domain_backup.py", line 271, in run
    smb_conn = smb_sysvol_conn(server, lp, creds)
  File "/usr/lib/python3/dist-packages/samba/netcmd/domain_backup.py", line 116, in smb_sysvol_conn
    return libsmb.Conn(server, "sysvol", lp=s3_lp, creds=creds, sign=True)
Comment 4 Stefan Metzmacher 2024-06-14 07:21:36 UTC 
(In reply to Thomas Karlsson from comment #3)

In what situation does that happen? A Windows DC only providing QUIC?

A backup without the sysvol content is useless.

I think we should not silently ignore the error,
an explicit --no-sysvol options would be ok if needed.
Comment 5 Thomas Karlsson 2024-06-17 17:19:14 UTC 
(In reply to Stefan Metzmacher from comment #4)

I only use Samba AD for authentication and authorisation (group handling) and not client management, so sysvol isn't used.
These options are in the smb.conf

server services = rpc, ldap, cldap, kdc, drepl, kcc, dnsupdate

The backup fails with these services.

I think the backup still is relevant without sysvol. For example the users and dns.
Comment 6 Stefan Metzmacher 2024-07-05 10:02:18 UTC 
(In reply to Thomas Karlsson from comment #5)

Ok, then an explicit --no-sysvol would work...
Comment 7 Thomas Karlsson 2024-07-05 17:25:12 UTC 
Created attachment 18364 [details]
Patch to enable a new option --no-sysvol for backup

Made a patch to enable the new option --no-sysvol