From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755712Ab1EFBDR (ORCPT ); Thu, 5 May 2011 21:03:17 -0400 Received: from kroah.org ([198.145.64.141]:36575 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755312Ab1EFAYS (ORCPT ); Thu, 5 May 2011 20:24:18 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Thu May 5 17:22:06 2011 Message-Id: <20110506002206.651062766@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Thu, 05 May 2011 17:20:01 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Herbert Xu , "David S. Miller" , Stephen Hemminger Subject: [016/143] udp: Fix bogus UFO packet generation In-Reply-To: <20110506002311.GA15354@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Herbert Xu commit 26cde9f7e2747b6d254b704594eed87ab959afa5 upstream. It has been reported that the new UFO software fallback path fails under certain conditions with NFS. I tracked the problem down to the generation of UFO packets that are smaller than the MTU. The software fallback path simply discards these packets. This patch fixes the problem by not generating such packets on the UFO path. Signed-off-by: Herbert Xu Reviewed-by: Michael S. Tsirkin Signed-off-by: David S. Miller Cc: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_output.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -867,8 +867,10 @@ int ip_append_data(struct sock *sk, !exthdrlen) csummode = CHECKSUM_PARTIAL; + skb = skb_peek_tail(&sk->sk_write_queue); + inet->cork.length += length; - if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) && + if (((length > mtu) || (skb && skb_is_gso(skb))) && (sk->sk_protocol == IPPROTO_UDP) && (rt->u.dst.dev->features & NETIF_F_UFO)) { err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, @@ -886,7 +888,7 @@ int ip_append_data(struct sock *sk, * adding appropriate IP header. */ - if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) + if (!skb) goto alloc_new_skb; while (length > 0) { @@ -1115,7 +1117,8 @@ ssize_t ip_append_page(struct sock *sk, return -EINVAL; inet->cork.length += size; - if ((sk->sk_protocol == IPPROTO_UDP) && + if ((size + skb->len > mtu) && + (sk->sk_protocol == IPPROTO_UDP) && (rt->u.dst.dev->features & NETIF_F_UFO)) { skb_shinfo(skb)->gso_size = mtu - fragheaderlen; skb_shinfo(skb)->gso_type = SKB_GSO_UDP;