Subject: Re: filehandles
To: Simon Burge <>
From: Jaromir Dolecek <>
List: tech-userlevel
Date: 12/05/1999 14:10:22
Simon Burge wrote:
> It looks like file handles should be unique (right?) but you can't get
> a filehandle unless you are root.  Is this restriction because of the
> directory access check bypass?  If so maybe when getfh() is run as
> non-root we could do the full directory access check.  Or is there a
> more sinister reason not to give out file handles to non-root processes?

The problem here is not getfh(), the problem are the other filehandle
routines. If you give them any random number as the filehandle, they
would try to do their staff without any checking if the filehandle
has been previously returned from getfh() call. So given you know
the filehandle of the file you want to access, you don't need
to call getfh() at all - so you can bypass the directory permissions.

Jaromir Dolecek <>
@@@@  Wanna a real operating system ? Go and get NetBSD, damn!  @@@@