a very quick glance through the manpage for smb.conf gives this:
Code:
valid users (S)
This is a list of users that should be allowed to login to this
service. Names starting with ´@´, ´+´ and ´&´ are interpreted using
the same rules as described in the invalid users parameter.
If this is empty (the default) then any user can login. If a
username is in both this list and the invalid users list then
access is denied for that user.
The current servicename is substituted for %S. This is useful in
the [homes] section.
Default: valid users = # No valid users list (anyone can login)
Example: valid users = greg, @pcusers
The same information can be gleaned from hundreds of examples and tutorials across the web. As a matter of fact, using a basic google search of
Code:
samba share restrict users
gives you the answer in the first hit. Maybe even in every one of the first 3-5 hits...
Just a little bit of searching on your part would have answered your question for you on the first day, and saved you some time.
Hopefully this gets you pointed in the right direction.