The commit be50da3e9d4a ("net: virtio_net: implement exact header length
guest feature") introduces support for the VIRTIO_NET_F_GUEST_HDRLEN
feature in virtio-net.
This feature requires virtio-net to set hdr_len to the actual header
length of the packet when transmitting, the number of
bytes from the start of the packet to the beginning of the
transport-layer payload.
However, in practice, hdr_len was being set using skb_headlen(skb),
which is clearly incorrect. This commit fixes that issue.
Fixes: be50da3e9d4a ("net: virtio_net: implement exact header length guest
feature")
Signed-off-by: Xuan Zhuo <[email protected]>
---
include/linux/virtio_net.h | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 710ae0d2d336..6ef0b737d548 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -217,25 +217,35 @@ static inline int virtio_net_hdr_from_skb(const struct
sk_buff *skb,
if (skb_is_gso(skb)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
+ u16 hdr_len = 0;
/* In certain code paths (such as the af_packet.c receive path),
* this function may be called without a transport header.
* In this case, we do not need to set the hdr_len.
*/
if (skb_transport_header_was_set(skb))
- hdr->hdr_len = __cpu_to_virtio16(little_endian,
- skb_headlen(skb));
+ hdr_len = skb_transport_offset(skb);
hdr->gso_size = __cpu_to_virtio16(little_endian,
sinfo->gso_size);
- if (sinfo->gso_type & SKB_GSO_TCPV4)
+ if (sinfo->gso_type & SKB_GSO_TCPV4) {
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
- else if (sinfo->gso_type & SKB_GSO_TCPV6)
+ if (hdr_len)
+ hdr_len += tcp_hdrlen(skb);
+ } else if (sinfo->gso_type & SKB_GSO_TCPV6) {
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
- else if (sinfo->gso_type & SKB_GSO_UDP_L4)
+ if (hdr_len)
+ hdr_len += tcp_hdrlen(skb);
+ } else if (sinfo->gso_type & SKB_GSO_UDP_L4) {
hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP_L4;
- else
+ if (hdr_len)
+ hdr_len += sizeof(struct udphdr);
+ } else {
return -EINVAL;
+ }
+
+ hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len);
+
if (sinfo->gso_type & SKB_GSO_TCP_ECN)
hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else
--
2.32.0.3.g01195cf9f
