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 --- 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