new feature: private IPC for every jail

[Robert Watson]

On Mon, 3 Apr 2006, Marc G. Fournier wrote:

> http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/48471
>
> [kernel] [patch] new feature: private IPC for every jail
>
> Its an ancient, 4.x patch for having private IPC in a jail ... not sure how 
> hard it would be to bring it up to 6.x / -current standards though ... but 
> it seems like something 'good' that is needed ...

In the past I've looked at doing things along these lines, but usually stall 
after a first hack when trying to decide how to deal with two critical issues:

(1) The fact that system v ipc primitives are loadable, and unloadable, which
     requires some careful handling relating to registration order, etc.

(2) The name space model for system v ipc is flat, so while it's desirable to
     allow the administrator in the host environment to monitor and control
     resource use in the jail (for example, delete allocated but unused
     segments), doing that requires developing an administrative model for it.

These challenges can be surmounted, but the doing them in a nice way requires 
some thought.

Robert N M Watson