[Samba] Make nmbd bind to interfaces only

[Nick Howitt]

Hi,
I would like to have nmbd only bind to the interfaces specified in the 
interfaces line of smb.conf, in the same way that smbd does. When 
researching this I did come across a mailing list thread saying there 
was no use case, but I think I have one.

For many years ClearOS has been providing NT4 style domains and 
unix-style shares. M$ upset the applecart last year with their 1803 
update when joining NT4 domains got broken (it has since been fixed 
since September '18, but I would assume the writing is on the wall for 
NT4 domains).

To get round the issue I loaded samba into docker using the 
https://github.com/Fmstrat/samba-domain container. I wanted to continue 
to use the ClearOS samba configuration (v4.7.1 and soon to follow Centos 
to 4.8.3) for its file-sharing as a domain member. One of the problems I 
had was that if the native ClearOS instance of samba was started, the 
docker instance would refuse to start because of a port clash. To get 
round this for smbd was easy. All I had to do was bind to interfaces 
only, but nmbd would not obey. For nmbd I had to set:

nmbd bind explicit broadcast = yes
socket address = 192.168.20.1

This is sort of OK if I have one LAN interface, but ClearOS is, among 
other things, a router/firewall and as such can have multiple LAN and/or 
VLAN interfaces. Socket address can only have one IP address so I can't 
get all LAN interfaces to bind to it. Is there a way round this or does 
it make a reasonable use case for a modification request.

Thanks,

Nick