We concluded that the skb_probe_transport_header() should better be called unconditionally. Avoiding the call into the flow dissector has also not really much to do with the direct xmit mode.
While it seems that only virtio_net code makes use of GSO from non RX/TX ring packet socket paths, we should probe for a transport header nevertheless before they hit devices. Reference: http://thread.gmane.org/gmane.linux.network/386173/ Signed-off-by: Daniel Borkmann <dan...@iogearbox.net> Cc: Jason Wang <jasow...@redhat.com> --- net/packet/af_packet.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 80c36c0..bdecf17 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2447,8 +2447,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, len = ((to_write > len_max) ? len_max : to_write); } - if (!packet_use_direct_xmit(po)) - skb_probe_transport_header(skb, 0); + skb_probe_transport_header(skb, 0); return tp_len; } @@ -2808,8 +2807,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) len += vnet_hdr_len; } - if (!packet_use_direct_xmit(po)) - skb_probe_transport_header(skb, reserve); + skb_probe_transport_header(skb, reserve); + if (unlikely(extra_len == 4)) skb->no_fcs = 1; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html