Magnus Karlsson wrote:
> From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
>
> Add support for directing a packet to any socket bound to the same
> umem. This makes it possible to use the XDP program to select what
> socket the packet should be received on. The user can populate the
> XSKMAP with various sockets and as long as they share the same umem,
> the XDP program can pick any one of them.
>
> Suggested-by: Yuval El-Hanany <yuvale@xxxxxxxxxxx>
> Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>
This will greatly simplify using AF_XDP sockets with standard RSS.
A socket can be attached to each NIC receive queue, and regardless to
which queue RSS directs a packet, the XDP program can pass it to the
AF_XDP socket that is the intended target.
In the trivial case a single AF_XDP socket receives all XDP_REDIRECT
traffic for the entire device. Similar to how a single PF_PACKET
socket can access all ingress traffic.
Though N fill queues still need to be maintained of course.
> ---
> net/xdp/xsk.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index 1eadfac03cc4..a339e9a1b557 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -313,10 +313,13 @@ static bool xsk_is_bound(struct xdp_sock *xs)
>
> static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
> {
> + struct net_device *dev = xdp->rxq->dev;
> + u32 qid = xdp->rxq->queue_index;
> +
> if (!xsk_is_bound(xs))
> return -ENXIO;
>
> - if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
> + if (!dev->_rx[qid].pool || xs->umem != dev->_rx[qid].pool->umem)
> return -EINVAL;
>
> if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) {
> --
> 2.42.0
>
