Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 15 Dec 1995 09:11:15 -0700
From:      Nate Williams <nate@rocky.sri.MT.net>
To:        "Frank ten Wolde" <franky@pinewood.nl>
Cc:        hackers@freebsd.org
Subject:   Re: Order of rules in ip_fw chain
Message-ID:  <199512151611.JAA16380@rocky.sri.MT.net>
In-Reply-To: <9512151302.ZM27077@pwood1.pinewood.nl>
References:  <9512151302.ZM27077@pwood1.pinewood.nl>

next in thread | previous in thread | raw e-mail | index | archive | help
> I have three questions/suggestions for discussion on the implementation of
> the ip firewall filter in FreeBSD 2.1.0.  I would like to see who shares
> my ideas or if there are sound reasons why *not* to modify the existing
> implementation...
> 
> Here I go:
> 
> 1) I would suggest adding the following lines of code in 
>    .../sys/netinet/ip_fw.c, line 879:
> 
> 	ifdef IPFIREWALL 
> 	int
> 	ip_fw_ctl(stage, m)
> 	    int stage;
> 	    struct mbuf *m; 
> 	{
>   
> 	    if (securelevel >= 2) {			NEW
> 	        return (EPERM);				NEW
> 	    }   					NEW

Just out of curiousity, how are you adding the lines to the firewall
list *before* the machine goes multi-user?  On my box, I can't simply
because the networking code isn't (yet) up and running.

> 2) I noticed that the order in which the fw checks incoming packets is
>    *not* the same as the order in which the packet rules were added.
>    IMHO this should be fixed.  I have not had the time (yet) to have
>    a look at the source myself, but will do so in the next few weeks.

Ugen was supposed to be working on this a while back.  I agree that
something should be done.  His work was going to allow 'priority' based
rules, which I agree would be a good thing.  Either that or allow the
rules to be listed in the same order in the kernel as they are added.
But, you'd need a way to modify the list in non-secure mode, so I think
the priority based approach is probably more flexible.



Nate



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199512151611.JAA16380>