From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: [PATCH 1/4] virtio_net: Fix skb->csum_start computation Date: Sun, 8 Jun 2008 20:49:00 +1000 Message-ID: <200806082049.00641.rusty@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org To: Jeff Garzik Return-path: Received: from ozlabs.org ([203.10.76.45]:33193 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759423AbYFHKtP (ORCPT ); Sun, 8 Jun 2008 06:49:15 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: From: Mark McLoughlin hdr->csum_start is the offset from the start of the ethernet header to the transport layer checksum field. skb->csum_start is the offset from skb->head. skb_partial_csum_set() assumes that skb->data points to the ethernet header - i.e. it computes skb->csum_start by adding the headroom to hdr->csum_start. Since eth_type_trans() skb_pull()s the ethernet header, skb_partial_csum_set() should be called before eth_type_trans(). (Without this patch, GSO packets from a guest to the world outside the host are corrupted). Signed-off-by: Mark McLoughlin Acked-by: Herbert Xu Signed-off-by: Rusty Russell --- drivers/net/virtio_net.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 50e6e59..503486f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -86,9 +86,7 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb, BUG_ON(len > MAX_PACKET_LEN); skb_trim(skb, len); - skb->protocol = eth_type_trans(skb, dev); - pr_debug("Receiving skb proto 0x%04x len %i type %i\n", - ntohs(skb->protocol), skb->len, skb->pkt_type); + dev->stats.rx_bytes += skb->len; dev->stats.rx_packets++; @@ -98,6 +96,10 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb, goto frame_err; } + skb->protocol = eth_type_trans(skb, dev); + pr_debug("Receiving skb proto 0x%04x len %i type %i\n", + ntohs(skb->protocol), skb->len, skb->pkt_type); + if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { pr_debug("GSO!\n"); switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {