From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932364AbcA2B2c (ORCPT ); Thu, 28 Jan 2016 20:28:32 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:33631 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753872AbcA2BYW (ORCPT ); Thu, 28 Jan 2016 20:24:22 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 196/210] ipv6: update skb->csum when CE mark is propagated Date: Thu, 28 Jan 2016 17:18:54 -0800 Message-Id: <1454030348-17736-197-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1454030348-17736-1-git-send-email-kamal@canonical.com> References: <1454030348-17736-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt14 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Eric Dumazet [ Upstream commit 34ae6a1aa0540f0f781dd265366036355fdc8930 ] When a tunnel decapsulates the outer header, it has to comply with RFC 6080 and eventually propagate CE mark into inner header. It turns out IP6_ECN_set_ce() does not correctly update skb->csum for CHECKSUM_COMPLETE packets, triggering infamous "hw csum failure" messages and stack traces. Signed-off-by: Eric Dumazet Acked-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- include/net/inet_ecn.h | 19 ++++++++++++++++--- net/ipv6/xfrm6_mode_tunnel.c | 2 +- 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h index 84b2083..0dc0a51 100644 --- a/include/net/inet_ecn.h +++ b/include/net/inet_ecn.h @@ -111,11 +111,24 @@ static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner) struct ipv6hdr; -static inline int IP6_ECN_set_ce(struct ipv6hdr *iph) +/* Note: + * IP_ECN_set_ce() has to tweak IPV4 checksum when setting CE, + * meaning both changes have no effect on skb->csum if/when CHECKSUM_COMPLETE + * In IPv6 case, no checksum compensates the change in IPv6 header, + * so we have to update skb->csum. + */ +static inline int IP6_ECN_set_ce(struct sk_buff *skb, struct ipv6hdr *iph) { + __be32 from, to; + if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph))) return 0; - *(__be32*)iph |= htonl(INET_ECN_CE << 20); + + from = *(__be32 *)iph; + to = from | htonl(INET_ECN_CE << 20); + *(__be32 *)iph = to; + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_add(csum_sub(skb->csum, from), to); return 1; } @@ -142,7 +155,7 @@ static inline int INET_ECN_set_ce(struct sk_buff *skb) case cpu_to_be16(ETH_P_IPV6): if (skb_network_header(skb) + sizeof(struct ipv6hdr) <= skb_tail_pointer(skb)) - return IP6_ECN_set_ce(ipv6_hdr(skb)); + return IP6_ECN_set_ce(skb, ipv6_hdr(skb)); break; } diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c index 901ef6f..5266ad2 100644 --- a/net/ipv6/xfrm6_mode_tunnel.c +++ b/net/ipv6/xfrm6_mode_tunnel.c @@ -24,7 +24,7 @@ static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) struct ipv6hdr *inner_iph = ipipv6_hdr(skb); if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) - IP6_ECN_set_ce(inner_iph); + IP6_ECN_set_ce(skb, inner_iph); } /* Add encapsulation header. -- 1.9.1