From patchwork Mon Dec 9 10:48:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Ivanov X-Patchwork-Id: 1206118 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=cambridgegreys.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47Wg0L1t2Zz9sP6 for ; Mon, 9 Dec 2019 21:48:33 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727249AbfLIKsc (ORCPT ); Mon, 9 Dec 2019 05:48:32 -0500 Received: from ivanoab7.miniserver.com ([37.128.132.42]:48036 "EHLO www.kot-begemot.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726377AbfLIKsc (ORCPT ); Mon, 9 Dec 2019 05:48:32 -0500 Received: from tun252.jain.kot-begemot.co.uk ([192.168.18.6] helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ieGab-0006Zn-PX; Mon, 09 Dec 2019 10:48:29 +0000 Received: from jain.kot-begemot.co.uk ([192.168.3.3]) by jain.kot-begemot.co.uk with esmtp (Exim 4.92) (envelope-from ) id 1ieGaY-0004SA-Th; Mon, 09 Dec 2019 10:48:28 +0000 From: anton.ivanov@cambridgegreys.com To: netdev@vger.kernel.org Cc: linux-um@lists.infradead.org, jasowang@redhat.com, mst@redhat.com, virtualization@lists.linux-foundation.org, Anton Ivanov 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@cambridgegreys.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Spam-Score: -1.0 X-Spam-Score: -1.0 X-Clacks-Overhead: GNU Terry Pratchett Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.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