Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754954AbcD0Abe (ORCPT ); Tue, 26 Apr 2016 20:31:34 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39834 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753747AbcDZXNk (ORCPT ); Tue, 26 Apr 2016 19:13:40 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Jesse Gross" Date: Wed, 27 Apr 2016 01:02:21 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 129/217] tunnels: Don't apply GRO to multiple layers of encapsulation. In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8426:ae4:c500:9cba:69ae:962d:6167 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2846 Lines: 87 3.16.35-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jesse Gross commit fac8e0f579695a3ecbc4d3cac369139d7f819971 upstream. When drivers express support for TSO of encapsulated packets, they only mean that they can do it for one layer of encapsulation. Supporting additional levels would mean updating, at a minimum, more IP length fields and they are unaware of this. No encapsulation device expresses support for handling offloaded encapsulated packets, so we won't generate these types of frames in the transmit path. However, GRO doesn't have a check for multiple levels of encapsulation and will attempt to build them. UDP tunnel GRO actually does prevent this situation but it only handles multiple UDP tunnels stacked on top of each other. This generalizes that solution to prevent any kind of tunnel stacking that would cause problems. Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack") Signed-off-by: Jesse Gross Signed-off-by: David S. Miller [bwh: Backported to 3.16: - Drop the ipip and sit cases - Adjust context] Signed-off-by: Ben Hutchings --- --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1759,8 +1759,8 @@ struct napi_gro_cb { /* Used in ipv6_gro_receive() */ u16 proto; - /* Used in udp_gro_receive */ - u16 udp_mark; + /* Used in tunnel GRO receive */ + u16 encap_mark; /* used to support CHECKSUM_COMPLETE for tunneling protocols */ __wsum csum; --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3974,7 +3974,7 @@ static enum gro_result dev_gro_receive(s NAPI_GRO_CB(skb)->same_flow = 0; NAPI_GRO_CB(skb)->flush = 0; NAPI_GRO_CB(skb)->free = 0; - NAPI_GRO_CB(skb)->udp_mark = 0; + NAPI_GRO_CB(skb)->encap_mark = 0; pp = ptype->callbacks.gro_receive(&napi->gro_list, skb); break; --- a/net/ipv4/gre_offload.c +++ b/net/ipv4/gre_offload.c @@ -154,6 +154,11 @@ static struct sk_buff **gre_gro_receive( struct packet_offload *ptype; __be16 type; + if (NAPI_GRO_CB(skb)->encap_mark) + goto out; + + NAPI_GRO_CB(skb)->encap_mark = 1; + off = skb_gro_offset(skb); hlen = off + sizeof(*greh); greh = skb_gro_header_fast(skb, off); --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -160,12 +160,12 @@ static struct sk_buff **udp_gro_receive( unsigned int hlen, off; int flush = 1; - if (NAPI_GRO_CB(skb)->udp_mark || + if (NAPI_GRO_CB(skb)->encap_mark || (!skb->encapsulation && skb->ip_summed != CHECKSUM_COMPLETE)) goto out; - /* mark that this skb passed once through the udp gro layer */ - NAPI_GRO_CB(skb)->udp_mark = 1; + /* mark that this skb passed once through the tunnel gro layer */ + NAPI_GRO_CB(skb)->encap_mark = 1; off = skb_gro_offset(skb); hlen = off + sizeof(*uh);