From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264310AbUANWMn (ORCPT ); Wed, 14 Jan 2004 17:12:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264342AbUANWMn (ORCPT ); Wed, 14 Jan 2004 17:12:43 -0500 Received: from sj-iport-4.cisco.com ([171.68.10.86]:20548 "EHLO sj-iport-4.cisco.com") by vger.kernel.org with ESMTP id S264310AbUANWMj (ORCPT ); Wed, 14 Jan 2004 17:12:39 -0500 To: James Morris Cc: linux-kernel@vger.kernel.org, , "David S. Miller" Subject: Re: [PATCH] Add CRC32C chksums to crypto routines References: From: Clay Haapala Organization: Cisco Systems, Inc. SRBU Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAHlBMVEXl5ufMrp3a4OLr6ujO lXzChGmsblZzRzjF1+ErFRAz+KIaAAACVElEQVR4nG3TQW/aMBQAYC9IO88dguyWUomqt0DQ do7koO22SXFQb6uE7XIMKrFya+mhPk8D43+79+wMyrp3gnx59nvxMxmNEnIWycgH+U9E55CO rkZJ8hYipbXTdfcvQK/Xy6JF2zqI+qpbjZAszSDG2oXYp0FI5mOqbAeuDtLBdeuO8fNVxkzr E9jklKEgQWsppYYf9v4IE3i/4RiVRPneQTpoXSM8QA7un3QZQ2cl54wXIH7VDwEmrdOiZBgF V5BiLwLM4B3BS0ZpB24d4IvzW+QIc7/JIcAQIadF2eeUzn3FAa6xWFYUotjIRmLB7vEvCC4t VAugpTrC2FleLBm2wVnlAc7Dl2u5L1UozgWCjTxMW+vb4GVVFhWWFSCdKmgDMhaNFoxL3bSH rc/Irn1/RcWlh+UqNgHeNwishJ1L6LCpjdmGz76RmFGyuSwLgLUxJhyUlLA7fHMpeSGVPsFA wqtK4voI8RE+I3DsDpfamSNMpIBTKrF1yIpPMA0AzQPU5gSwCTyC/aEAtX4NM6gLM3CCziBT jRR+StQ/AA8a7AMuwxn0YAmcRKnVGwDRiOcw3uMWlajgAJsAPbw4OIpwrH3/vdq9B7hpl7GD w61A4PxwSqyH9J25gePnYdqhYjjZ5s6QCb3bwvOLJWPBFvCvWVDSthYmcff44IcacOUOt1Yv yGCF1+twuQtQCPjzZIaK/Lrx9+6b7TKEdXTwgz8R+uJv5K1jOcWMnO7NJ3v/QlprnzP1deUe 8j4CpVE82MRj4j5SHGDnfvul8uGwjqNnpf4Ak4pzJDIy3lkAAAAASUVORK5CYII= Date: Wed, 14 Jan 2004 16:12:31 -0600 In-Reply-To: (James Morris's message of "Wed, 14 Jan 2004 16:45:49 -0500 (EST)") Message-ID: User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.5 (celeriac, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 14 Jan 2004, James Morris stated: > On Wed, 14 Jan 2004, Clay Haapala wrote: > >> This patch against 2.6.1 adds CRC32C checksumming capabilities to >> the crypto routines. The structure of it is based wholly on the >> existing digest (md5) routines, the main difference being that >> chksums are often used in an "accumulator" fashion, effectively >> requiring one to set the seed, and the digest algorithms don't do >> that. > > This looks interesting; do you know of any other chksum algorithms > which might need to be implemented in the kernel? > I reference the one other user of CRC32C in my code, that would be the sctp network driver, at this time. Of course, there is library/crc32, which I did make an attempt to implement companion code to it, but we really need the "work over scatterlists" feature of the crypto routines. I took the design goals the of the library/crc32 routines (flexible XOR policy, flexible initial values) and tried to allow that in the crypto chksum routines. CRC32 could be moved into it, but the uses of CRC32 are often quick accumulation over packet fragments, rather than computing digests over scatterlists describing would can be many K of data. -- Clay Haapala (chaapala@cisco.com) Cisco Systems SRBU +1 763-398-1056 6450 Wedgwood Rd, Suite 130 Maple Grove MN 55311 PGP: C89240AD Funny, I didn't think Haliburton was into aerospace.