From patchwork Tue Aug 28 21:48:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick McHardy X-Patchwork-Id: 180572 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id C0A8D2C00BE for ; Wed, 29 Aug 2012 07:50:37 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753482Ab2H1VtE (ORCPT ); Tue, 28 Aug 2012 17:49:04 -0400 Received: from stinky.trash.net ([213.144.137.162]:59144 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753092Ab2H1VtD (ORCPT ); Tue, 28 Aug 2012 17:49:03 -0400 Received: from gw.localnet (localhost [127.0.0.1]) by stinky.trash.net (Postfix) with ESMTP id 05F9FB2C48; Tue, 28 Aug 2012 23:49:02 +0200 (MEST) From: Patrick McHardy To: pablo@netfilter.org Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 02/19] Cleaning up the IPv6 MTU checking in the IPVS xmit code, by using a common helper function __mtu_check_toobig_v6(). Date: Tue, 28 Aug 2012 23:48:42 +0200 Message-Id: <1346190539-9963-3-git-send-email-kaber@trash.net> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1346190539-9963-1-git-send-email-kaber@trash.net> References: <1346190539-9963-1-git-send-email-kaber@trash.net> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jesper Dangaard Brouer The MTU check for tunnel mode can also use this helper as ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) is qual to skb->len. And the 'mtu' variable have been adjusted before calling helper. Notice, this also fixes a bug, as the the MTU check in ip_vs_dr_xmit_v6() were missing a check for skb_is_gso(). This bug e.g. caused issues for KVM IPVS setups, where different Segmentation Offloading techniques are utilized, between guests, via the virtio driver. This resulted in very bad performance, due to the ICMPv6 "too big" messages didn't affect the sender. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Patrick McHardy --- net/netfilter/ipvs/ip_vs_xmit.c | 21 +++++++++++++++------ 1 files changed, 15 insertions(+), 6 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c index 543a554..67a3978 100644 --- a/net/netfilter/ipvs/ip_vs_xmit.c +++ b/net/netfilter/ipvs/ip_vs_xmit.c @@ -85,6 +85,15 @@ __ip_vs_dst_check(struct ip_vs_dest *dest, u32 rtos) return dst; } +static inline bool +__mtu_check_toobig_v6(const struct sk_buff *skb, u32 mtu) +{ + if (skb->len > mtu && !skb_is_gso(skb)) { + return true; /* Packet size violate MTU size */ + } + return false; +} + /* Get route to daddr, update *saddr, optionally bind route to saddr */ static struct rtable *do_output_route4(struct net *net, __be32 daddr, u32 rtos, int rt_mode, __be32 *saddr) @@ -491,7 +500,7 @@ ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, /* MTU checking */ mtu = dst_mtu(&rt->dst); - if (skb->len > mtu && !skb_is_gso(skb)) { + if (__mtu_check_toobig_v6(skb, mtu)) { if (!skb->dev) { struct net *net = dev_net(skb_dst(skb)->dev); @@ -712,7 +721,7 @@ ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, /* MTU checking */ mtu = dst_mtu(&rt->dst); - if (skb->len > mtu && !skb_is_gso(skb)) { + if (__mtu_check_toobig_v6(skb, mtu)) { if (!skb->dev) { struct net *net = dev_net(skb_dst(skb)->dev); @@ -946,8 +955,8 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, if (skb_dst(skb)) skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); - if (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) && - !skb_is_gso(skb)) { + /* MTU checking: Notice that 'mtu' have been adjusted before hand */ + if (__mtu_check_toobig_v6(skb, mtu)) { if (!skb->dev) { struct net *net = dev_net(skb_dst(skb)->dev); @@ -1113,7 +1122,7 @@ ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, /* MTU checking */ mtu = dst_mtu(&rt->dst); - if (skb->len > mtu) { + if (__mtu_check_toobig_v6(skb, mtu)) { if (!skb->dev) { struct net *net = dev_net(skb_dst(skb)->dev); @@ -1349,7 +1358,7 @@ ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, /* MTU checking */ mtu = dst_mtu(&rt->dst); - if (skb->len > mtu && !skb_is_gso(skb)) { + if (__mtu_check_toobig_v6(skb, mtu)) { if (!skb->dev) { struct net *net = dev_net(skb_dst(skb)->dev);