From patchwork Tue Jul 7 05:34:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Timo Teras X-Patchwork-Id: 492050 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 C13741402BE for ; Tue, 7 Jul 2015 15:34:26 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=qHeXm7pR; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751619AbbGGFeW (ORCPT ); Tue, 7 Jul 2015 01:34:22 -0400 Received: from mail-la0-f54.google.com ([209.85.215.54]:33093 "EHLO mail-la0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751391AbbGGFeU (ORCPT ); Tue, 7 Jul 2015 01:34:20 -0400 Received: by laar3 with SMTP id r3so181624521laa.0 for ; Mon, 06 Jul 2015 22:34:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; bh=SQJBLwdKK1rc/gBZCIMEZZvkO+sLA5eLPoAhIVttSrU=; b=qHeXm7pR52BO6qM2FPIVhuaUmbpJZAc3NqQB1Tqd3Wysn/wUVf2CDHFfIpxdPIXDnN fPAFyTJ6BL9gJZBXzIjQFcJigpqAl4Wy6zxKj27k5VkjdjqlhfTvbQAoBqWravSAcXf3 EthEOaJqGbQVouV+Ahvyaf5JXZ+NsiChM/u7KUD/Xf5qvjq3dCLngcHw87yxWGdfHaVb jmyWpgT02p+pM2LIsBFQFIzlf9AVnJ13vkez3Ns4vo6iMaZTZacKxziX1gPISTVfNtXJ H+ldtnNUzdGCuFKDvW1J1VsFr0Y2kuovSJplyOmKT9beT9GsprGdhD7ZLHUjkx8R54MP dLXw== X-Received: by 10.152.87.231 with SMTP id bb7mr2317506lab.16.1436247259053; Mon, 06 Jul 2015 22:34:19 -0700 (PDT) Received: from vostro.util.wtbts.net ([83.145.235.199]) by mx.google.com with ESMTPSA id j2sm5283733lam.45.2015.07.06.22.34.17 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 06 Jul 2015 22:34:18 -0700 (PDT) From: =?UTF-8?q?Timo=20Ter=C3=A4s?= To: netdev Cc: =?UTF-8?q?Timo=20Ter=C3=A4s?= , Pravin B Shelar Subject: [PATCH net, v2] ip_tunnel: fix ipv4 pmtu check to honor inner ip header df Date: Tue, 7 Jul 2015 08:34:13 +0300 Message-Id: <1436247253-6466-1-git-send-email-timo.teras@iki.fi> X-Mailer: git-send-email 2.4.5 In-Reply-To: <20150707033906.GF1173@brightrain.aerifal.cx> References: <20150707033906.GF1173@brightrain.aerifal.cx> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- Should go to -stable queues (3.12.y and newer). v2: revised commit message wording a bit, and added signed-off-by line that was forgotten accidentally. 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 4c2c3ba..626d9e5 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -586,7 +586,8 @@ 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; @@ -603,7 +604,8 @@ 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; @@ -737,7 +739,7 @@ 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; }