From: Hangbin Liu <liuhangbin@xxxxxxxxx> commit dfed913e8b55a0c2c4906f1242fd38fd9a116e49 upstream. Currently, the kernel drops GSO VLAN tagged packet if it's created with socket(AF_PACKET, SOCK_RAW, 0) plus virtio_net_hdr. The reason is AF_PACKET doesn't adjust the skb network header if there is a VLAN tag. Then after virtio_net_hdr_set_proto() called, the skb->protocol will be set to ETH_P_IP/IPv6. And in later inet/ipv6_gso_segment() the skb is dropped as network header position is invalid. Let's handle VLAN packets by adjusting network header position in packet_parse_headers(). The adjustment is safe and does not affect the later xmit as tap device also did that. In packet_snd(), packet_parse_headers() need to be moved before calling virtio_net_hdr_set_proto(), so we can set correct skb->protocol and network header first. There is no need to update tpacket_snd() as it calls packet_parse_headers() in tpacket_fill_skb(), which is already before calling virtio_net_hdr_* functions. skb->no_fcs setting is also moved upper to make all skb settings together and keep consistency with function packet_sendmsg_spkt(). Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxx> Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220425014502.985464-1-liuhangbin@xxxxxxxxx Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/packet/af_packet.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1864,12 +1864,20 @@ oom: static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) { + int depth; + if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && sock->type == SOCK_RAW) { skb_reset_mac_header(skb); skb->protocol = dev_parse_header_protocol(skb); } + /* Move network header to the right position for VLAN tagged packets */ + if (likely(skb->dev->type == ARPHRD_ETHER) && + eth_type_vlan(skb->protocol) && + __vlan_get_protocol(skb, skb->protocol, &depth) != 0) + skb_set_network_header(skb, depth); + skb_probe_transport_header(skb); } @@ -2979,6 +2987,11 @@ static int packet_snd(struct socket *soc skb->mark = sockc.mark; skb->tstamp = sockc.transmit_time; + if (unlikely(extra_len == 4)) + skb->no_fcs = 1; + + packet_parse_headers(skb, sock); + if (has_vnet_hdr) { err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); if (err) @@ -2987,11 +3000,6 @@ static int packet_snd(struct socket *soc virtio_net_hdr_set_proto(skb, &vnet_hdr); } - packet_parse_headers(skb, sock); - - if (unlikely(extra_len == 4)) - skb->no_fcs = 1; - err = po->xmit(skb); if (unlikely(err != 0)) { if (err > 0)
