From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH v2] ipv6: GRO should be ECN friendly Date: Sat, 06 Oct 2012 08:43:30 +0200 Message-ID: <1349505810.21172.198.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Herbert Xu , netdev To: David Miller Return-path: Received: from mail-we0-f174.google.com ([74.125.82.174]:48850 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952Ab2JFGnm (ORCPT ); Sat, 6 Oct 2012 02:43:42 -0400 Received: by mail-we0-f174.google.com with SMTP id t9so1500959wey.19 for ; Fri, 05 Oct 2012 23:43:40 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet IPv4 side of the problem was addressed in commit a9e050f4e7f9d (net: tcp: GRO should be ECN friendly) This patch does the same, but for IPv6 : A Traffic Class mismatch doesnt mean flows are different, but instead should force a flush of previous packets. This patch removes artificial packet reordering problem. Signed-off-by: Eric Dumazet Cc: Herbert Xu --- v2: sparse friendly version net/ipv6/af_inet6.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index e22e6d8..f757e3b 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -880,22 +880,25 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head, nlen = skb_network_header_len(skb); for (p = *head; p; p = p->next) { - struct ipv6hdr *iph2; + const struct ipv6hdr *iph2; + __be32 first_word; /* */ if (!NAPI_GRO_CB(p)->same_flow) continue; iph2 = ipv6_hdr(p); + first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ; - /* All fields must match except length. */ + /* All fields must match except length and Traffic Class. */ if (nlen != skb_network_header_len(p) || - memcmp(iph, iph2, offsetof(struct ipv6hdr, payload_len)) || + (first_word & htonl(0xF00FFFFF)) || memcmp(&iph->nexthdr, &iph2->nexthdr, nlen - offsetof(struct ipv6hdr, nexthdr))) { NAPI_GRO_CB(p)->same_flow = 0; continue; } - + /* flush if Traffic Class fields are different */ + NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000)); NAPI_GRO_CB(p)->flush |= flush; }