Date: Tue, 16 Jul 2013 04:32:49 -0700 From: Loganaden Velvindron <logan@elandsys.com> To: Andre Oppermann <andre@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: Improved SYN Cookies: Looking for testers Message-ID: <20130716113249.GA6638@mx.elandsys.com> In-Reply-To: <51DE6E86.6080707@freebsd.org> References: <51DA68B8.6070201@freebsd.org> <20130710151821.5a8cf38a@fabiankeil.de> <51DE6E86.6080707@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, Jul 11, 2013 at 10:36:22AM +0200, Andre Oppermann wrote: > On 10.07.2013 15:18, Fabian Keil wrote: > >Andre Oppermann <andre@freebsd.org> wrote: > > > >>We have a SYN cookie implementation for quite some time now but it > >>has some limitations with current realities for window scaling and > >>SACK encoding the in the few available bits. > >> > >>This patch updates and improves SYN cookies mainly by: > >> > >> a) encoding of MSS, WSCALE (window scaling) and SACK into the ISN > >> (initial sequence number) without the use of timestamp bits. > >> > >> b) switching to the very fast and cryptographically strong SipHash-2-4 > >> hash MAC algorithm to protect the SYN cookie against forgery. > >> > >>The patch had been reviewed by dwmalone (cookies) and cperciva (siphash). > >> > >>Please find it here for testing: > >> > >> http://people.freebsd.org/~andre/syncookie-20130708.diff > > > >I've been using the patch for a couple of days and didn't notice any > >issues so far. Privoxy's regression tests continue to work as expected > >as well. > > Thanks for testing and reporting back. We are currently downloading FreeBSD -current snapshot for testing. Unfortunately, we've been hit by a number of SYN flood attacks recently, and your patch looks very promising. Would there be interest in reviewing backported patched for 9.x release ? > > Could you test with net.inet.tcp.log_debug and net.inet.tcp.syncookies_only=1 > as well to bypass the syn cache entirely? > > It will give a bit of debug log output which is it telling you mostly about > rounding to the next nearest index value. You can send the output privately > to me to spot unexpected outliers, if any. > > >BTW, I think kern/173309 could be closed. > > OK. > > -- > Andre > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130716113249.GA6638>