From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roberto Nibali Subject: Re: TCP window tracking patch status query for further design considerations Date: Wed, 09 Oct 2002 01:15:36 +0200 Sender: netfilter-devel-admin@lists.netfilter.org Message-ID: <3DA36718.7010903@drugphish.ch> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Roberto Nibali , Netfilter-devel Return-path: To: Jozsef Kadlecsik Errors-To: netfilter-devel-admin@lists.netfilter.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Id: netfilter-devel.vger.kernel.org > Read Guido's article on which the patch is based: > http://www.iane.nl/users/guido/papers/tcp_filtering.ps.gz I actually did, even twice, but not carefully enough. > The constant is a little bit bigger than the maximal possible window size > without window scaling. The macro tries to take window scaling into > account. Got it. >>Shouldn't it be (or what is the point of having MAXACKWINCONST): >> >>+#define MAXACKWINDOW(sender) ((sender)->td_maxwin > MAXACKWINCONST ? >> MAXACKWINCONST : (sender)->td_maxwin) > > > No, it'd make the possible ACK window smaller in the case of window > scaling. Makes sense now, why didn't it before? > Those packets are either corrupted or invalid ones sent deliberately > and would (wrongly) be reported as out of window ones. > Most of the out of window log entries created by the earlier patch > releases was generated because the code was not protected against such > packets. I understand. Thank you. Regards, Roberto Nibali, ratz -- echo '[q]sa[ln0=aln256%Pln256/snlbx]sb3135071790101768542287578439snlbxq'|dc