From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [net-next 4/5] netback: set transport header before passing it to kernel Date: Tue, 26 Mar 2013 14:19:58 +0800 Message-ID: <1364278799-37285-5-git-send-email-jasowang@redhat.com> References: <1364278799-37285-1-git-send-email-jasowang@redhat.com> Cc: mst@redhat.com, Jason Wang , Eric Dumazet , Ian Campbell To: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1364278799-37285-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Currently, for the packets receives from netback, before doing header check, kernel just reset the transport header in netif_receive_skb() which pretends non l4 header. This is suboptimal for precise packet length estimation (introduced in 1def9238: net_sched: more precise pkt_len computation) which needs correct l4 header for gso packets. The patch just reuse the header probed by netback for partial checksum packets and tries to use skb_flow_dissect() for other cases, if both fail, just pretend no l4 header. Cc: Eric Dumazet Cc: Ian Campbell Signed-off-by: Jason Wang --- drivers/net/xen-netback/netback.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index aa28550..fc8faa7 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -39,6 +39,7 @@ #include #include +#include #include #include @@ -1184,6 +1185,7 @@ static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) if (th >= skb_tail_pointer(skb)) goto out; + skb_set_transport_header(skb, 4 * iph->ihl); skb->csum_start = th - skb->head; switch (iph->protocol) { case IPPROTO_TCP: @@ -1495,6 +1497,7 @@ static void xen_netbk_tx_submit(struct xen_netbk *netbk) skb->dev = vif->dev; skb->protocol = eth_type_trans(skb, skb->dev); + skb_reset_network_header(skb); if (checksum_setup(vif, skb)) { netdev_dbg(vif->dev, @@ -1503,6 +1506,15 @@ static void xen_netbk_tx_submit(struct xen_netbk *netbk) continue; } + if (!skb_transport_header_was_set(skb)) { + struct flow_keys keys; + + if (skb_flow_dissect(skb, &keys)) + skb_set_transport_header(skb, keys.thoff); + else + skb_reset_transport_header(skb); + } + vif->dev->stats.rx_bytes += skb->len; vif->dev->stats.rx_packets++; -- 1.7.1