From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754628AbbHEVxS (ORCPT ); Wed, 5 Aug 2015 17:53:18 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:38826 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754461AbbHEVuq (ORCPT ); Wed, 5 Aug 2015 17:50:46 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Pravin B Shelar , =?UTF-8?q?Timo=20Ter=C3=A4s?= , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 099/107] ip_tunnel: fix ipv4 pmtu check to honor inner ip header df Date: Wed, 5 Aug 2015 14:49:31 -0700 Message-Id: <1438811379-384-100-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1438811379-384-1-git-send-email-kamal@canonical.com> References: <1438811379-384-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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-ckt5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: =?UTF-8?q?Timo=20Ter=C3=A4s?= commit fc24f2b2094366da8786f59f2606307e934cea17 upstream. Frag needed should be sent only if the inner header asked to not fragment. Currently fragmentation is broken if the tunnel has df set, but df was not asked in the original packet. The tunnel's df needs to be still checked to update internally the pmtu cache. Commit 23a3647bc4f93bac broke it, and this commit fixes the ipv4 df check back to the way it was. Fixes: 23a3647bc4f93bac ("ip_tunnels: Use skb-len to PMTU check.") Cc: Pravin B Shelar Signed-off-by: Timo Teräs Acked-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/ipv4/ip_tunnel.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index d3e4479..d1e208b 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -587,7 +587,8 @@ int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t, EXPORT_SYMBOL(ip_tunnel_encap); static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, - struct rtable *rt, __be16 df) + struct rtable *rt, __be16 df, + const struct iphdr *inner_iph) { struct ip_tunnel *tunnel = netdev_priv(dev); int pkt_size = skb->len - tunnel->hlen - dev->hard_header_len; @@ -604,7 +605,8 @@ static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, if (skb->protocol == htons(ETH_P_IP)) { if (!skb_is_gso(skb) && - (df & htons(IP_DF)) && mtu < pkt_size) { + (inner_iph->frag_off & htons(IP_DF)) && + mtu < pkt_size) { memset(IPCB(skb), 0, sizeof(*IPCB(skb))); icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); return -E2BIG; @@ -738,7 +740,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, goto tx_error; } - if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) { + if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off, inner_iph)) { ip_rt_put(rt); goto tx_error; } -- 1.9.1