From mboxrd@z Thu Jan 1 00:00:00 1970 From: anton.ivanov@cambridgegreys.com Subject: [PATCH] virtio: Work around frames incorrectly marked as gso Date: Mon, 9 Dec 2019 10:48:24 +0000 Message-ID: <20191209104824.17059-1-anton.ivanov__1570.09332194633$1575890491$gmane$org@cambridgegreys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: netdev@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, linux-um@lists.infradead.org, Anton Ivanov , mst@redhat.com List-Id: virtualization@lists.linuxfoundation.org From: Anton Ivanov Some of the frames marked as GSO which arrive at virtio_net_hdr_from_skb() have no GSO_TYPE, no fragments (data_len = 0) and length significantly shorter than the MTU (752 in my experiments). This is observed on raw sockets reading off vEth interfaces in all 4.x and 5.x kernels I tested. These frames are reported as invalid while they are in fact gso-less frames. This patch marks the vnet header as no-GSO for them instead of reporting it as invalid. Signed-off-by: Anton Ivanov --- include/linux/virtio_net.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 0d1fe9297ac6..d90d5cff1b9a 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -112,8 +112,12 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; else if (sinfo->gso_type & SKB_GSO_TCPV6) hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; - else - return -EINVAL; + else { + if (skb->data_len == 0) + hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; + else + return -EINVAL; + } if (sinfo->gso_type & SKB_GSO_TCP_ECN) hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; } else -- 2.20.1