Date: Sun, 3 Aug 2003 05:45:19 +0100 From: Andy Gilligan <andy@evo6.org> To: Mike Wade <mwade@bluehighway.net> Cc: freebsd-net@freebsd.org Subject: Re: ipfw2 mac address matching weirdness? Message-ID: <20030803044519.GA32629@vega.evo6.net> In-Reply-To: <20030802223846.V4501@net-ninja.dyndns.org> References: <20030802203114.J4501@net-ninja.dyndns.org> <20030803020257.GA79533@vega.evo6.net> <20030802223846.V4501@net-ninja.dyndns.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Aug 03, 2003 at 03:39:24AM BST, Mike Wade wrote: > On Sun, 3 Aug 2003, Andy Gilligan wrote: > > > On Sun, Aug 03, 2003 at 01:31:23AM BST, Mike Wade wrote: > > > I'm running FreeBSD 4.8 RELEASE w/ IPFW2 support enabled. I'm running > > > into some weirdness with the mac address matching feature or perhaps it's > > > my lack of understanding how it interacts with other rules. :) > > > > > > My goal is to transparently redirect everything except a few select MAC > > > addresses but it doesn't appear to work properly. For example: > > > > > > net-ninja# ipfw list > > > 00001 skipto 65535 ip from any to any MAC any any in via sis0 > > > 00002 fwd 127.0.0.1,8080 tcp from any to any dst-port 80 in via sis0 > > > 65535 allow ip from any to any > > > > > > This should allow every MAC address to bypass the transparent redirect but > > > it doesn't. If I change rule #1 to: > > > > > > 00001 skipto 65535 ip from any to any in via sis0 > > > > > > Things work as advertised. Any ideas? > > > > Try: > > > > sysctl net.link.ether.ipfw=1 > > Hmm, it was already set: > > net-ninja# sysctl net.link.ether.ipfw > net.link.ether.ipfw: 1 The best advice I can give at the moment is to read the "PACKET FLOW" section in ipfw(8). A brief read over it suggests that it *may* not be possible to do what you ask, due to the rules being parsed twice. (in your case) The first pass is done from ether_demux(), and this will only match the first rule - it won't match tcp or dst-port 80, etc. The second pass will come from ip_input(), which will only match the second rule, as it doesn't know anything about MAC addresses. I could be missing something (it is 4am), so hopefully somebody will step in and tell me I'm wrong :) Sorry I couldn't be of more help. Best regards, -Andy
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030803044519.GA32629>