[PATCH net v1 3/3] virtio-net: correct hdr_len handling for tunnel gso
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2025-10-11 09:41:18
Also in:
virtualization
Subsystem:
the rest, virtio core, virtio net driver · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
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.
Fixes: a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
include/linux/virtio_net.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 10ca53b3a399..742cce34a24e 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h@@ -403,6 +403,7 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)vhdr; unsigned int inner_nh, outer_th; int tnl_gso_type; + u16 hdr_len; int ret; tnl_gso_type = skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_TUNNEL |
@@ -434,6 +435,23 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, outer_th = skb->transport_header - skb_headroom(skb); vhdr->inner_nh_offset = cpu_to_le16(inner_nh); vhdr->outer_th_offset = cpu_to_le16(outer_th); + + switch (skb->inner_ipproto) { + case IPPROTO_TCP: + hdr_len = inner_tcp_hdrlen(skb); + break; + + case IPPROTO_UDP: + hdr_len = sizeof(struct udphdr); + break; + + default: + return -EINVAL; + } + + hdr_len += skb_inner_transport_offset(skb); + hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len); + return 0; }
--
2.32.0.3.g01195cf9f