On Sat, 16 Feb 2008, Stef Bon wrote:
> Chris Stromsoe wrote:
> 
>> My eventual solution was to use multi-mount to bind mount a shared 
>> directory with libraries and other common data to a "simple" generated 
>> path as a container, and then bind mount the hashed directory inside of 
>> that volume.  I'm using the container volume as a chroot environment to 
>> run untrusted code (php) on a web server, and wanted to minimize 
>> exposure to the rest of the machine as much as possible.
> 
> Ok, it's more clear to me now. I'm wondering, isn't it possible to 
> create a custom "chroot" command, which will of course do the chroot, 
> but also do the necessary binds.

Probably.  But I have over 35k virtual hosts.  I need to have the mounts 
expire after some period of non-use.  Having the chroot process handle the 
binds means that I would need to have some other process sitting around to 
unmount everything after a period of inactivity.  Which might as well be 
autofs at that point.

> I've been working on a login shell (chroot_union) which is the standard 
> shell of a user. When this user logs in (starts a session) a copy of the 
> system is created with unionfs. Then a chroot is done, and a perfect 
> environment where the user can do anything is there. Isn't that 
> possible?

The server is only accessible via ftp and http.  I'm trying to limit the 
environment only to what is necessary to run and nothing more.  If I were 
trying to provide a more complete environment with shell access it might 
make sense to use unionfs, but I'm not doing anything that complex. Autofs 
managing the bind mounts (together with a chroot cgi wrapper to limit 
access) covers everything I need.


-Chris

_______________________________________________
autofs mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/autofs

Reply via email to