From: "Michael S. Tsirkin" <mst@redhat•com>
To: Hangbin Liu <liuhangbin@gmail•com>
Cc: netdev@vger•kernel.org, Jason Wang <jasowang@redhat•com>,
"David S . Miller" <davem@davemloft•net>,
Jakub Kicinski <kuba@kernel•org>, Paolo Abeni <pabeni@redhat•com>,
Maxim Mikityanskiy <maximmi@mellanox•com>,
Willem de Bruijn <WillemdeBruijnwillemdebruijn.kernel@gmail•com>,
Balazs Nemeth <bnemeth@redhat•com>,
Mike Pattrick <mpattric@redhat•com>,
Eric Dumazet <edumazet@google•com>
Subject: Re: [PATCHv2 net-next] net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO
Date: Mon, 25 Apr 2022 09:52:55 -0400 [thread overview]
Message-ID: <20220425095235-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20220425014502.985464-1-liuhangbin@gmail.com>
On Mon, Apr 25, 2022 at 09:45:02AM +0800, Hangbin Liu wrote:
> 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@gmail•com>
Acked-by: Michael S. Tsirkin <mst@redhat•com>
> ---
>
> v2: Rewrite commit description, no code update.
> ---
> net/packet/af_packet.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
> index 243566129784..fd31334cf688 100644
> --- a/net/packet/af_packet.c
> +++ b/net/packet/af_packet.c
> @@ -1924,12 +1924,20 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
>
> 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);
> }
>
> @@ -3047,6 +3055,11 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
> 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)
> @@ -3055,11 +3068,6 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
> 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)
> --
> 2.35.1
next prev parent reply other threads:[~2022-04-25 13:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-25 1:45 [PATCHv2 net-next] net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO Hangbin Liu
2022-04-25 6:21 ` Hangbin Liu
2022-04-25 13:49 ` Willem de Bruijn
2022-04-25 13:52 ` Michael S. Tsirkin [this message]
2022-04-26 9:30 ` patchwork-bot+netdevbpf
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