File & Directory permissions

Peter Polkinghorne Peter.Polkinghorne at
Tue Nov 10 12:45:10 GMT 1998

[The following is my understanding from doco and experiments - hosts Solaris 
2.5.1 and Samba 1.9.18p3, client NT 4.0 - please re-use if wanted]

Samba presents a DOS file permissions view to users.  That is they can set the 
following attributes for files: Archive, Hidden and Readonly.  As an ordinary 
user on NT 4.0 System attribute is not accessible.

These attributes map as follows onto the following default Unix permissions - 
note owner and group will depend on how connected to Samba and any "force 
user" and "force group" directives.  Also as far as I can tell the Hidden 
attribute has no effect on Unix permissions and is never reported back even if 
set.  Finally the permissions for directories (or folders) seems to be 

Attributes	Type	Unix permissions

none		file	-rw-rw-rw-
Archive		file	-rwxrw-rw-
ReadOnly	file	-r--r--r--
Archive+ReadOnly file	-r-xr--r--

any	     directory	drwxrwsrwx

These permissions are the logically ANDed with "create mask" for files and 
"directory mask" for directories.

Finally thet are logically ORed with "force create mask" for files and "force 
directory create mask" for directories.

The only control as user at a NT Workstation has is to make files read only.

[Now for my questions:]

A: Is the above correct?

B: Is there any other mechanism for a user to change the permissions of their 

I realise that this has a lot to do with differeing filesystem semantics.  
Also I would be content with a little add on helper program for NT or what 
ever to affect the UNIX permissions of their files mounted from SAMBA.

The rationale is that the SAMBA directives do not cover all I would wish - eg 
Users here have Web pages that must be globally readable, but most other files 
should not be so.

| Peter Polkinghorne, Computer Centre, Brunel University, Uxbridge, UB8 3PH,|
| Peter.Polkinghorne at   +44 1895 274000 x2561       UK          |

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