Re: expected behavior of PF_PACKET on NETIF_F_HW_VLAN_RX device?

From: Stephen Hemminger
Date: Wed Oct 31 2007 - 15:35:10 EST


On Wed, 31 Oct 2007 14:43:51 -0400
Dave Johnson <djohnson+linux-kernel@xxxxxxxxxxxxxxxxxxxxxx> wrote:

>
> Depending on the network driver, I'm seeing different behavior if
> a .1q packet is received to an PF_PACKET, SOCK_RAW, ETH_P_ALL socket.
>
>
> On devices what do not use NETIF_F_HW_VLAN_RX, the packet socket gets
> the complete packet with vlan tag included as the driver simply calls
> netif_receive_skb() or equivilant. packet_rcv() then gets the whole
> thing vlan tag included and sends this through the socket.
>
> vlan_skb_recv() also gets these all and will drop them because there
> are no vlans configured.
>

The VLAN acceleration grabs and hides the tag. It is a design flaw
that should be fixed, feel free to post a patch.


--
Stephen Hemminger <shemminger@xxxxxxxxxxxxxxxxxxxx>
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