[ovs-dev] [v3 05/10] lib/daemon: all daemons works with the --user option

[Ben Pfaff]

On Mon, Sep 14, 2015 at 03:54:09PM -0700, Andy Zhou wrote:
> All daemons launched by root can drop their privilege using
> --user option. See man page update form more details.
> 
> Signed-off-by: Andy Zhou <azhou at nicira.com>

What worries me about this is that it relies on developers to remember
to add a call to daemon_become_new_user() to every daemon.  If we forget
one, it's a security hole: --user will be silently ignored.

Is it possible to integrate daemon_become_new_user() into some other
function that has to be called for daemonization to work?  For example,
can we integrate it into daemon_start()?  Or can we at least avoid the
security hole by, say, aborting in daemonize_complete() if
daemon_become_new_user() hasn't been called?