From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: How exactly does CHECKSUM_COMPLETE works? Date: Tue, 30 Sep 2014 16:14:24 -0400 (EDT) Message-ID: <20140930.161424.679705969149272577.davem@davemloft.net> References: <1412104977.30721.94.camel@edumazet-glaptop2.roam.corp.google.com> <1412105832.30721.95.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: Yuval.Mintz@qlogic.com, therbert@google.com, netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:49340 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751695AbaI3UO0 (ORCPT ); Tue, 30 Sep 2014 16:14:26 -0400 In-Reply-To: <1412105832.30721.95.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Tue, 30 Sep 2014 12:37:12 -0700 > On Tue, 2014-09-30 at 12:22 -0700, Eric Dumazet wrote: >> On Tue, 2014-09-30 at 19:05 +0000, Yuval Mintz wrote: >> >> > Can you pinpoint me to what exactly in the code corrects NAPI_GRO_CB(skb)->csum >> > by negating the ipv4 part in the ones' complete checksum? >> > >> > E.g., for ipv6 [in ipv6_gro_receive()] I can see that skb_gro_postpull_rcsum() is >> > called after pulling the ipv6 header [and before proceeding to the next protocol], >> > but I can't seem to find anything similar to this for ipv4 [in inet_gro_receive()]. >> > >> >> >> IPv4 header is supposed to have a 0 checksum ;) >> > > Or if you prefer : Someone please submit this formally :)