On Fri, 2 Apr 2004, Rui Miguel Seabra wrote: > On Fri, 2004-04-02 at 10:21 -0500, Robert P. J. Day wrote: > > On Fri, 2 Apr 2004, Rui Miguel Seabra wrote: > > > > > On Fri, 2004-04-02 at 07:40 -0500, murphy pope wrote: > > > > >Many users in /etc/passwd can be mapped to a single SELinux user for > > > > access control purposes (e.g. system_u). > > > > > > > > Sounds like /etc/group to me. > > > > > > Ok, let's say you have users john, jane, doe, and poe > > > > > > then you have groups like: > > > staff:x:n:john,jane,doe > > > > > > and file xpto: > > > > > > -rw-rw-r-- 1 john staff 3399 Mar 9 00:40 xpto > > > > > > How do you forbid doe from writing on xpto? > > > > > > That's an example of what SELinux brings you, in terms of permissions. > > > You can explictly say xpto can't be written by doe. > > > > on the other hand, why should you be *allowed* to prevent doe from > > writing on xpto? you've explicitly made doe part of the staff group, > > and you've explicitly given the staff group write permission on that > > file. seems like these regular perms are doing exactly what they're > > *supposed* to be doing, no? > > No. doe might be a junior staff member, for instance. then why would you make "doe" a member of "staff" in the first place? again, i *know* what you're getting at. what i'm arguing is that many of the examples i see promoting the use of extended permissions, including ACLs, are little more than a misuse of standard permissions. in the above, you create a group called "staff", assign user "doe" to such a group, then complain that user doe has, well, "staff" rights. what exactly were you expecting? > Other instance I didn't say: > > How do you make poe be able to write to the file without making him a > member of group staff or making the file world writable? ok, that's a better question, and represents a much better example. > Rui > > > unless i've totally misread what you were getting at. > > You must've missed the point of ACLs. au contraire, i understand ACLs pretty well. all i'm harping on is the sometimes lame examples people use to justify their existence. there's enough *good* justification for ACLs that one shouldn't need to dredge up *bad* justification. :-) rday
