From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcin Giedz Subject: Re: question Date: Thu, 27 Oct 2005 12:25:49 +0200 Message-ID: <200510271225.50084.marcin.giedz@eulerhermes.pl> References: <200510270955.20466.marcin.giedz@eulerhermes.pl> <200510271140.34417.marcin.giedz@eulerhermes.pl> <1130407490.8832.10.camel@laptop3> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1130407490.8832.10.camel@laptop3> Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-bounces@lists.netfilter.org Errors-To: netfilter-bounces@lists.netfilter.org Content-Type: text/plain; charset="iso-8859-1" To: oan@frozentux.net Cc: netfilter@lists.netfilter.org Dnia czwartek, 27 pa=BCdziernika 2005 12:04, Oskar Andreasson napisa=B3: > Hi Marcin, > > iptables and netfilter will not do the job, unless you are willing to > sacrifice stability and security. The problem is that the strings that > netfilter will see are broken down into smaller pieces. So the string > "iptables and netfilter" might actually be transmitted as "iptables and" > and then "netfilter" in a separate packet. On top of this, people might > try to intentionally break your filters by fragmenting the above string > into "i", "p", "t", ... etc packets. > > The good thing to do in this case, is to wait until the TCP stream has > reached the application layer and has been reassembled properly. Hence, > you will want to either write your own proxy, or to use someone elses > proxy. > > If you want to use it, I just uploaded a tunnel/proxy program to > http://www.frozentux.net/stunnel.tgz. This is an unfinished program I > started on a couple of years ago. It is written in C. It is horribly > coded and pretty much sucks, but it has no memory leaks and might serve > as a starting point. Great!!! Really thanks but I just can't reach your program - above address= =20 doesn't work :( Could you please do something or send the program on my=20 private mail. Thanks once again, Marcin > > Have a nice day;). > > On Thu, 2005-10-27 at 11:40 +0200, Marcin Giedz wrote: > > Dnia czwartek, 27 pa=BCdziernika 2005 11:09, Ruprecht Helms napisa=B3: > > > Marcin Giedz wrote: > > > > I don't get it :( > > > > How with tcpdump as tcpdump is only dump traffic tool - as I know it > > > > can't change anything or I'm wrong? > > > > > > You are right. As I know it only dump. > > > What you need is a hexeditor or you are looking for a tool that do > > > hexediting in the fly. > > > > Absolutely! > > > > > But that is offtopic in this list. > > > > But I really don't know where to start? Perhaps some did it earlier. > > > > Marcin > > > > > Regards, > > > Ruprecht