Re: [PATCH 2/3] Add new input plugin UNIXSOCK

[Pierre Chifflier <pchifflier@edenwall.com>]

On Fri, Sep 04, 2009 at 01:54:42AM +0200, Jan Engelhardt wrote:
> >+/* Default unix socket path */
> >+#define UNIXSOCK_UNIXPATH_DEFAULT	"/tmp/ulogd2.sock"
> 
> That does not look like a good default path, though it might be
> configurable at runtime. It seems that, because sockets are
> world-connectable by default, random users could spam your socket.
> 
> Subsequently, there also seems to be an easy DoS whereby a user process 
> only needs to connect to block a legitimate program from sending packets 
> to the module.


True, when using unix socket you always have to set path, permissions
and chown it  ...

Maybe this could even be an option of ulogd.conf: unixsock_perms and
unixsock_owner ?

> 
> Finally, but this is not so much of a problem, a user could also create 
> ulogd2.sock first and then receive potentially interesting packets from 
> a legitimate program that thought it would connect to ulogd2.
> 
> I would just move it out to, for example, /var/run/ulogd/ulogd2.sock
> so one can set restrictions on /var/run/ulogd as needed.

Indeed, the only drawback is that the plugin will fail if the parent
directory does not exist.

Pierre