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]>
---
arch/um/drivers/vector_transports.c | 1 +
drivers/net/tun_vnet.h | 4 ++--
drivers/net/virtio_net.c | 9 +++++++--
include/linux/virtio_net.h | 26 +++++++++++++++++++++-----
net/packet/af_packet.c | 5 +++--
5 files changed, 34 insertions(+), 11 deletions(-)
diff --git a/arch/um/drivers/vector_transports.c
b/arch/um/drivers/vector_transports.c
index 0794d23f07cb..03c5baa1d0c1 100644
--- a/arch/um/drivers/vector_transports.c
+++ b/arch/um/drivers/vector_transports.c
@@ -121,6 +121,7 @@ static int raw_form_header(uint8_t *header,
vheader,
virtio_legacy_is_little_endian(),
false,
+ false,
0
);
diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h
index 81662328b2c7..0d376bc70dd7 100644
--- a/drivers/net/tun_vnet.h
+++ b/drivers/net/tun_vnet.h
@@ -214,7 +214,7 @@ static inline int tun_vnet_hdr_from_skb(unsigned int flags,
if (virtio_net_hdr_from_skb(skb, hdr,
tun_vnet_is_little_endian(flags), true,
- vlan_hlen)) {
+ false, vlan_hlen)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
if (net_ratelimit()) {
@@ -244,7 +244,7 @@ tun_vnet_hdr_tnl_from_skb(unsigned int flags,
if (virtio_net_hdr_tnl_from_skb(skb, tnl_hdr, has_tnl_offload,
tun_vnet_is_little_endian(flags),
- vlan_hlen)) {
+ false, vlan_hlen)) {
struct virtio_net_hdr_v1 *hdr = &tnl_hdr->hash_hdr.hdr;
struct skb_shared_info *sinfo = skb_shinfo(skb);
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0369dda5ed60..b335c88a8cd6 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3317,9 +3317,13 @@ static int xmit_skb(struct send_queue *sq, struct
sk_buff *skb, bool orphan)
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
struct virtnet_info *vi = sq->vq->vdev->priv;
struct virtio_net_hdr_v1_hash_tunnel *hdr;
- int num_sg;
unsigned hdr_len = vi->hdr_len;
+ bool hdrlen_negotiated;
bool can_push;
+ int num_sg;
+
+ hdrlen_negotiated = virtio_has_feature(vi->vdev,
+ VIRTIO_NET_F_GUEST_HDRLEN);
pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
@@ -3339,7 +3343,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff
*skb, bool orphan)
hdr = &skb_vnet_common_hdr(skb)->tnl_hdr;
if (virtio_net_hdr_tnl_from_skb(skb, hdr, vi->tx_tnl,
- virtio_is_little_endian(vi->vdev), 0))
+ virtio_is_little_endian(vi->vdev),
+ hdrlen_negotiated, 0))
return -EPROTO;
if (vi->mergeable_rx_bufs)
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index b673c31569f3..3cd8b2ebc197 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -211,16 +211,15 @@ static inline int virtio_net_hdr_from_skb(const struct
sk_buff *skb,
struct virtio_net_hdr *hdr,
bool little_endian,
bool has_data_valid,
+ bool hdrlen_negotiated,
int vlan_hlen)
{
memset(hdr, 0, sizeof(*hdr)); /* no info leak */
if (skb_is_gso(skb)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
+ u16 hdr_len;
- /* This is a hint as to how much should be linear. */
- hdr->hdr_len = __cpu_to_virtio16(little_endian,
- skb_headlen(skb));
hdr->gso_size = __cpu_to_virtio16(little_endian,
sinfo->gso_size);
if (sinfo->gso_type & SKB_GSO_TCPV4)
@@ -231,6 +230,21 @@ static inline int virtio_net_hdr_from_skb(const struct
sk_buff *skb,
hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP_L4;
else
return -EINVAL;
+
+ if (hdrlen_negotiated) {
+ hdr_len = skb_transport_offset(skb);
+
+ if (hdr->gso_type == VIRTIO_NET_HDR_GSO_UDP_L4)
+ hdr_len += sizeof(struct udphdr);
+ else
+ hdr_len += tcp_hdrlen(skb);
+ } else {
+ /* This is a hint as to how much should be linear. */
+ hdr_len = skb_headlen(skb);
+ }
+
+ 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
@@ -384,6 +398,7 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb,
struct virtio_net_hdr_v1_hash_tunnel *vhdr,
bool tnl_hdr_negotiated,
bool little_endian,
+ bool hdrlen_negotiated,
int vlan_hlen)
{
struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)vhdr;
@@ -395,7 +410,7 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb,
SKB_GSO_UDP_TUNNEL_CSUM);
if (!tnl_gso_type)
return virtio_net_hdr_from_skb(skb, hdr, little_endian, false,
- vlan_hlen);
+ hdrlen_negotiated, vlan_hlen);
/* Tunnel support not negotiated but skb ask for it. */
if (!tnl_hdr_negotiated)
@@ -408,7 +423,8 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb,
/* Let the basic parsing deal with plain GSO features. */
skb_shinfo(skb)->gso_type &= ~tnl_gso_type;
- ret = virtio_net_hdr_from_skb(skb, hdr, true, false, vlan_hlen);
+ ret = virtio_net_hdr_from_skb(skb, hdr, true, false, hdrlen_negotiated,
+ vlan_hlen);
skb_shinfo(skb)->gso_type |= tnl_gso_type;
if (ret)
return ret;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 173e6edda08f..6982f4ab1c73 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2093,7 +2093,8 @@ static int packet_rcv_vnet(struct msghdr *msg, const
struct sk_buff *skb,
return -EINVAL;
*len -= vnet_hdr_sz;
- if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr,
vio_le(), true, 0))
+ if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr,
+ vio_le(), true, false, 0))
return -EINVAL;
return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz);
@@ -2361,7 +2362,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct
net_device *dev,
if (vnet_hdr_sz &&
virtio_net_hdr_from_skb(skb, h.raw + macoff -
sizeof(struct virtio_net_hdr),
- vio_le(), true, 0)) {
+ vio_le(), true, false, 0)) {
if (po->tp_version == TPACKET_V3)
prb_clear_blk_fill_status(&po->rx_ring);
goto drop_n_account;
--
2.32.0.3.g01195cf9f
