From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] sctp: identify chunks that need to be fragmented at IP level Date: Fri, 09 Sep 2016 19:18:52 -0700 (PDT) Message-ID: <20160909.191852.1305298210334990557.davem@davemloft.net> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org, marcelo.leitner@gmail.com, vyasevich@gmail.com, daniel@iogearbox.net To: lucien.xin@gmail.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:35554 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752015AbcIJCS4 (ORCPT ); Fri, 9 Sep 2016 22:18:56 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Xin Long Date: Thu, 8 Sep 2016 17:54:11 +0800 > From: Marcelo Ricardo Leitner > > Previously, without GSO, it was easy to identify it: if the chunk didn't > fit and there was no data chunk in the packet yet, we could fragment at > IP level. So if there was an auth chunk and we were bundling a big data > chunk, it would fragment regardless of the size of the auth chunk. This > also works for the context of PMTU reductions. > > But with GSO, we cannot distinguish such PMTU events anymore, as the > packet is allowed to exceed PMTU. > > So we need another check: to ensure that the chunk that we are adding, > actually fits the current PMTU. If it doesn't, trigger a flush and let > it be fragmented at IP level in the next round. > > Signed-off-by: Marcelo Ricardo Leitner Applied.