From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [RFC 0/3] TCP congestion control RTT patches Date: Thu, 19 Jul 2007 08:41:29 +0100 Message-ID: <20070719074129.670215301@linux-foundation.org> Cc: Sangtae Ha To: "David S. Miller" Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:42162 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763075AbXGSIYc (ORCPT ); Thu, 19 Jul 2007 04:24:32 -0400 Cc: Luca De Cicco Cc: Gavin McCullagh Cc: netdev@vger.kernel.org Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org These patches deal with issues brought up by Gavin McCullagh about reactions of Cubic and HTCP to hostile receivers that return bogus timestamp options. In a couple of places the timestamp value is used in ways that could cause unfairness. The solution in these patches is to only use local values to measure RTT for congestion control. The timestamp is still used as described in RFC's to measure RTT used for retransmit timer. This code is preliminary and not throughly tested yet. It could be backported to 2.6.22 for stable kernels, but it would be hard to go back to earlier kernels because it builds on the recent TCP congestion control API changes. --