Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754575AbaFCLm0 (ORCPT ); Tue, 3 Jun 2014 07:42:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43726 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932836AbaFCLmU (ORCPT ); Tue, 3 Jun 2014 07:42:20 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , Florian Westphal , "David S. Miller" , Luis Henriques Subject: [PATCH 3.11 098/138] net: core: don't account for udp header size when computing seglen Date: Tue, 3 Jun 2014 12:39:04 +0100 Message-Id: <1401795584-22664-99-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1401795584-22664-1-git-send-email-luis.henriques@canonical.com> References: <1401795584-22664-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 6d39d589bb76ee8a1c6cde6822006ae0053decff upstream. In case of tcp, gso_size contains the tcpmss. For UFO (udp fragmentation offloading) skbs, gso_size is the fragment payload size, i.e. we must not account for udp header size. Otherwise, when using virtio drivers, a to-be-forwarded UFO GSO packet will be needlessly fragmented in the forward path, because we think its individual segments are too large for the outgoing link. Fixes: fe6cc55f3a9a053 ("net: ip, ipv6: handle gso skbs in forwarding path") Cc: Eric Dumazet Reported-by: Tobias Brunner Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- net/core/skbuff.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index ba05e044aed8..abcad83cece3 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3505,12 +3505,14 @@ EXPORT_SYMBOL_GPL(skb_scrub_packet); unsigned int skb_gso_transport_seglen(const struct sk_buff *skb) { const struct skb_shared_info *shinfo = skb_shinfo(skb); - unsigned int hdr_len; if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) - hdr_len = tcp_hdrlen(skb); - else - hdr_len = sizeof(struct udphdr); - return hdr_len + shinfo->gso_size; + return tcp_hdrlen(skb) + shinfo->gso_size; + + /* UFO sets gso_size to the size of the fragmentation + * payload, i.e. the size of the L4 (UDP) header is already + * accounted for. + */ + return shinfo->gso_size; } EXPORT_SYMBOL_GPL(skb_gso_transport_seglen); -- 1.9.1 -- 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/