Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757602AbaDXWO3 (ORCPT ); Thu, 24 Apr 2014 18:14:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39834 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756756AbaDXVxM (ORCPT ); Thu, 24 Apr 2014 17:53:12 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xin Long , Hannes Frederic Sowa , "David S. Miller" Subject: [PATCH 3.4 08/27] ipv6: ip6_append_data_mtu do not handle the mtu of the second fragment properly Date: Thu, 24 Apr 2014 14:55:42 -0700 Message-Id: <20140424215552.192344192@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140424215551.942390050@linuxfoundation.org> References: <20140424215551.942390050@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: lucien [ Upstream commit e367c2d03dba4c9bcafad24688fadb79dd95b218 ] In ip6_append_data_mtu(), when the xfrm mode is not tunnel(such as transport),the ipsec header need to be added in the first fragment, so the mtu will decrease to reserve space for it, then the second fragment come, the mtu should be turn back, as the commit 0c1833797a5a6ec23ea9261d979aa18078720b74 said. however, in the commit a493e60ac4bbe2e977e7129d6d8cbb0dd236be, it use *mtu = min(*mtu, ...) to change the mtu, which lead to the new mtu is alway equal with the first fragment's. and cannot turn back. when I test through ping6 -c1 -s5000 $ip (mtu=1280): ...frag (0|1232) ESP(spi=0x00002000,seq=0xb), length 1232 ...frag (1232|1216) ...frag (2448|1216) ...frag (3664|1216) ...frag (4880|164) which should be: ...frag (0|1232) ESP(spi=0x00001000,seq=0x1), length 1232 ...frag (1232|1232) ...frag (2464|1232) ...frag (3696|1232) ...frag (4928|116) so delete the min() when change back the mtu. Signed-off-by: Xin Long Fixes: 75a493e60ac4bb ("ipv6: ip6_append_data_mtu did not care about pmtudisc and frag_size") Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_output.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1194,21 +1194,19 @@ static void ip6_append_data_mtu(unsigned unsigned int fragheaderlen, struct sk_buff *skb, struct rt6_info *rt, - bool pmtuprobe) + unsigned int orig_mtu) { if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { if (skb == NULL) { /* first fragment, reserve header_len */ - *mtu = *mtu - rt->dst.header_len; + *mtu = orig_mtu - rt->dst.header_len; } else { /* * this fragment is not first, the headers * space is regarded as data space. */ - *mtu = min(*mtu, pmtuprobe ? - rt->dst.dev->mtu : - dst_mtu(rt->dst.path)); + *mtu = orig_mtu; } *maxfraglen = ((*mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); @@ -1225,7 +1223,7 @@ int ip6_append_data(struct sock *sk, int struct ipv6_pinfo *np = inet6_sk(sk); struct inet_cork *cork; struct sk_buff *skb, *skb_prev = NULL; - unsigned int maxfraglen, fragheaderlen, mtu; + unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu; int exthdrlen; int dst_exthdrlen; int hh_len; @@ -1310,6 +1308,7 @@ int ip6_append_data(struct sock *sk, int dst_exthdrlen = 0; mtu = cork->fragsize; } + orig_mtu = mtu; hh_len = LL_RESERVED_SPACE(rt->dst.dev); @@ -1392,8 +1391,7 @@ alloc_new_skb: if (skb == NULL || skb_prev == NULL) ip6_append_data_mtu(&mtu, &maxfraglen, fragheaderlen, skb, rt, - np->pmtudisc == - IPV6_PMTUDISC_PROBE); + orig_mtu); skb_prev = skb; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/