From owner-freebsd-net@FreeBSD.ORG Wed May 28 10:19:12 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BCFF61065680 for ; Wed, 28 May 2008 10:19:12 +0000 (UTC) (envelope-from stefan.lambrev@moneybookers.com) Received: from blah.sun-fish.com (blah.sun-fish.com [217.18.249.150]) by mx1.freebsd.org (Postfix) with ESMTP id 5F5928FC13 for ; Wed, 28 May 2008 10:19:11 +0000 (UTC) (envelope-from stefan.lambrev@moneybookers.com) Received: by blah.sun-fish.com (Postfix, from userid 1002) id A8DF11B10EF9; Wed, 28 May 2008 12:19:10 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on malcho.cmotd.com X-Spam-Level: X-Spam-Status: No, score=-10.3 required=5.0 tests=ALL_TRUSTED,BAYES_00, MIME_8BIT_HEADER autolearn=no version=3.2.4 Received: from hater.haters.org (hater.cmotd.com [192.168.3.125]) by blah.sun-fish.com (Postfix) with ESMTP id 628DC1B10CB6; Wed, 28 May 2008 12:19:08 +0200 (CEST) Message-ID: <483D319B.7030303@moneybookers.com> Date: Wed, 28 May 2008 13:19:07 +0300 From: Stefan Lambrev User-Agent: Thunderbird 2.0.0.14 (X11/20080503) MIME-Version: 1.0 To: =?UTF-8?B?RXJtYWwgTHXDp2k=?= References: <1211891010.00075594.1211880013@10.7.7.3> <1211894613.00075634.1211884201@10.7.7.3> <1211901827.00075710.1211890802@10.7.7.3> <483C4636.7080608@mavhome.dp.ua> <483C4D48.6020106@moneybookers.com> <9a542da30805271114w6ad82569m43d89c4cd03a76fc@mail.gmail.com> In-Reply-To: <9a542da30805271114w6ad82569m43d89c4cd03a76fc@mail.gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: ClamAV version 0.93, clamav-milter version 0.93 on blah.cmotd.com X-Virus-Status: Clean Cc: freebsd-net@freebsd.org Subject: Re: Adjust Maximum Segment Size? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 May 2008 10:19:12 -0000 Ermal Lu=C3=A7i wrote: > On Tue, May 27, 2008 at 8:04 PM, Stefan Lambrev > wrote: > =20 >> Greetings, >> >> Alexander Motin wrote: >> =20 >>> Stefan Lambrev wrote: >>> =20 >>>>> Yes, You can with ng_tcpmss >>>>> =20 >>>> Isn't it doable only with ipfw/divert when using ng_tcpmss? >>>> I have and some concerns about performance too .. >>>> =20 >>> There are several ways to inject packet to ng_tcpmss: >>> - ipfw + divert + ng_ksocket. It should be faster then usual user-le= vel >>> implementation >>> - ipfw + netgraph as described in ng_tcpmss(4) >>> - use ng_tcpmss directly in some complicated netgraph setup. For exa= mple, >>> mpd is able to use it. This is probably the fastest and easiest way, = but >>> only for some setups. >>> =20 >> Thanks for all ideas. >> I think I'll try the route -mtu feature. >> Looks like easier for implementation and testing. :) >> Anyway it will be good if we have such feature in the base system. >> It shouldn't be very difficult? :) >> >> -- >> =20 > > Actually converting ng_tcpmss to pfil(9) should be easy. > =20 I'm thinking about adding additional checks in tcp_mss() and=20 tcp_mssopt() - both in sys/netinet/tcp_input.c plus two sysctl entries for max mss and max mss IPv6. Does it sound like a reasonable solution or I'm missing something? P.S. One of the things that bothers me is that pf uses it's own=20 pf_get_mss() and pf_calc_mss() and they should be fixed accordingly? --=20 Best Wishes, Stefan Lambrev ICQ# 24134177