From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: Where exactly will arch_fast_hash be used Date: Sun, 07 Dec 2014 14:14:40 +0100 Message-ID: <1417958080.17658.32.camel@localhost> References: <20141207052041.20498.qmail@ns.horizon.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: herbert@gondor.apana.org.au, dborkman@redhat.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, tgraf@suug.ch To: George Spelvin Return-path: Received: from out3-smtp.messagingengine.com ([66.111.4.27]:38363 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751487AbaLGNOn (ORCPT ); Sun, 7 Dec 2014 08:14:43 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id E53E7207CF for ; Sun, 7 Dec 2014 08:14:42 -0500 (EST) In-Reply-To: <20141207052041.20498.qmail@ns.horizon.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi, On So, 2014-12-07 at 00:20 -0500, George Spelvin wrote: > If you want DoS-resistant hash tables, I'm working on adding SipHash > to the kernel. > > This is a keyed pseudo-random function designed specifically for that > application. I am starting with ext4 directory hashes, and then intended > to expand to secure sequence numbers (since it's far faster than MD5). Please consider xfs, too. AFAIK xfs doesn't seed their hashing so far and the hashing function is pretty weak. One example: http://marc.info/?l=linux-xfs&m=139590613002926&w=2 > (I'm trying to figure out a good interface, since the crypto API > is a bit heavy for something to heavily optimized.) Ack. If we want to use it in the networking stack we should be able to use it without a dependency to the crypto framework. Bye, Hannes