From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B8AA31715B for ; Fri, 20 Mar 2026 02:18:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773973107; cv=none; b=bQiUNQ4YXnF+2qlRyKFrNwzu1q0oo0wB1BFvJZn53cVCO8xCrE7RmUfpCM91VUX0KnOIMhnYoLZIk5pCO1n/hSXvJkuSUUhI5L8URFJngkSeQ3SzHbqHpvK9m1V7SLRo1/V8U6TDSiR2D/qM2vZoFV/t6PqXEo8NT7Y4NBljncY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773973107; c=relaxed/simple; bh=gkCCSUG+tAWJxFJwITZ4fIB/AcZgP6bz6RePWzuGUDI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZLM3bnJaVWO4GtO1avTPU64BAYKc/pR8le0kq/tBSQd74jD3pEasTFqxkm2jQ9sUTxQPj0n0arELixG7ODSFuBDHrfYWaH6D+/QKSp4Ahjs6jSIGCs0hWUCiouvUoq37jqaZcUxeVwbkxEfoN3MV2lAdtz9Sy1k24DcSAeRbur8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=BRwuzjkd; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="BRwuzjkd" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1773973102; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=QbxyY/wBc3wzMKmZVEKZ8V/Nan0s6YXbH2oRNSo1Joo=; b=BRwuzjkdJBvd3WL/NwVurdE/Xead7VL60FK6eVm1lZMdQVpK1/d0cESDOn77ZiOLL31ht7m3Lpi4SJf5qxfs/maSfImkZoagxtx36cKOHSY9o/0ocPINXRHaEMBwvOy/TYlCsLsufKxjKlgUhoBqIzSVhAKaNlsMx9kupR8tUEM= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033045098064;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0X.JxA7r_1773973100; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0X.JxA7r_1773973100 cluster:ay36) by smtp.aliyun-inc.com; Fri, 20 Mar 2026 10:18:20 +0800 From: Xuan Zhuo To: netdev@vger.kernel.org Cc: Willem de Bruijn , Jason Wang , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Jiri Pirko , Alvaro Karsz , virtualization@lists.linux.dev Subject: [PATCH net v11 2/2] virtio-net: correct hdr_len handling for tunnel gso Date: Fri, 20 Mar 2026 10:18:18 +0800 Message-Id: <20260320021818.111741-3-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20260320021818.111741-1-xuanzhuo@linux.alibaba.com> References: <20260320021818.111741-1-xuanzhuo@linux.alibaba.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Git-Hash: b52cc70b415f Content-Transfer-Encoding: 8bit The commit a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.") introduces support for the UDP GSO tunnel feature in virtio-net. The virtio spec says: If the \field{gso_type} has the VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV4 bit or VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6 bit set, \field{hdr_len} accounts for all the headers up to and including the inner transport. The commit did not update the hdr_len to include the inner transport. I observed that the "hdr_len" is 116 for this packet: 17:36:18.241105 52:55:00:d1:27:0a > 2e:2c:df:46:a9:e1, ethertype IPv4 (0x0800), length 2912: (tos 0x0, ttl 64, id 45197, offset 0, flags [none], proto UDP (17), length 2898) 192.168.122.100.50613 > 192.168.122.1.4789: [bad udp cksum 0x8106 -> 0x26a0!] VXLAN, flags [I] (0x08), vni 1 fa:c3:ba:82:05:ee > ce:85:0c:31:77:e5, ethertype IPv4 (0x0800), length 2862: (tos 0x0, ttl 64, id 14678, offset 0, flags [DF], proto TCP (6), length 2848) 192.168.3.1.49880 > 192.168.3.2.9898: Flags [P.], cksum 0x9266 (incorrect -> 0xaa20), seq 515667:518463, ack 1, win 64, options [nop,nop,TS val 2990048824 ecr 2798801412], length 2796 116 = 14(mac) + 20(ip) + 8(udp) + 8(vxlan) + 14(inner mac) + 20(inner ip) + 32(innner tcp) Fixes: a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.") Signed-off-by: Xuan Zhuo --- include/linux/virtio_net.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 361b60c8be68..f36d21b5bc19 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -224,6 +224,22 @@ static inline void __virtio_net_set_hdrlen(const struct sk_buff *skb, hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len); } +/* This function must be called after virtio_net_hdr_from_skb(). */ +static inline void __virtio_net_set_tnl_hdrlen(const struct sk_buff *skb, + struct virtio_net_hdr *hdr) +{ + u16 hdr_len; + + hdr_len = skb_inner_transport_offset(skb); + + if (hdr->gso_type == VIRTIO_NET_HDR_GSO_UDP_L4) + hdr_len += sizeof(struct udphdr); + else + hdr_len += inner_tcp_hdrlen(skb); + + hdr->hdr_len = __cpu_to_virtio16(true, hdr_len); +} + static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, struct virtio_net_hdr *hdr, bool little_endian, @@ -440,6 +456,9 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, if (ret) return ret; + if (feature_hdrlen && hdr->hdr_len) + __virtio_net_set_tnl_hdrlen(skb, hdr); + if (skb->protocol == htons(ETH_P_IPV6)) hdr->gso_type |= VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6; else -- 2.32.0.3.g01195cf9f