On Mon, Nov 23, 2020 at 07:36:21PM +0200, Camelia Groza wrote:
> Implement the ndo_change_mtu callback to prevent users from setting an
> MTU that would permit processing of S/G frames. The maximum MTU size
> is dependent on the buffer size.
>
> Acked-by: Madalin Bucur <madalin.bu...@oss.nxp.com>
> Signed-off-by: Camelia Groza <camelia.gr...@nxp.com>
> ---
> drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 40
> ++++++++++++++++++++------
> 1 file changed, 31 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> index 8acce62..ee076f4 100644
> --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> @@ -2756,23 +2756,44 @@ static int dpaa_eth_stop(struct net_device *net_dev)
> return err;
> }
>
> +static bool xdp_validate_mtu(struct dpaa_priv *priv, int mtu)
> +{
> + int max_contig_data = priv->dpaa_bp->size - priv->rx_headroom;
> +
> + /* We do not support S/G fragments when XDP is enabled.
> + * Limit the MTU in relation to the buffer size.
> + */
> + if (mtu + VLAN_ETH_HLEN + ETH_FCS_LEN > max_contig_data) {
Do you support VLAN double tagging? We normally take into acount to two vlan
headers in these checks.
Other than that:
Reviewed-by: Maciej Fijalkowski <maciej.fijalkow...@intel.com>
> + dev_warn(priv->net_dev->dev.parent,
> + "The maximum MTU for XDP is %d\n",
> + max_contig_data - VLAN_ETH_HLEN - ETH_FCS_LEN);
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static int dpaa_change_mtu(struct net_device *net_dev, int new_mtu)
> +{
> + struct dpaa_priv *priv = netdev_priv(net_dev);
> +
> + if (priv->xdp_prog && !xdp_validate_mtu(priv, new_mtu))
> + return -EINVAL;
> +
> + net_dev->mtu = new_mtu;
> + return 0;
> +}
> +
> static int dpaa_setup_xdp(struct net_device *net_dev, struct bpf_prog *prog)
> {
> struct dpaa_priv *priv = netdev_priv(net_dev);
> struct bpf_prog *old_prog;
> - int err, max_contig_data;
> + int err;
> bool up;
>
> - max_contig_data = priv->dpaa_bp->size - priv->rx_headroom;
> -
> /* S/G fragments are not supported in XDP-mode */
> - if (prog &&
> - (net_dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN > max_contig_data)) {
> - dev_warn(net_dev->dev.parent,
> - "The maximum MTU for XDP is %d\n",
> - max_contig_data - VLAN_ETH_HLEN - ETH_FCS_LEN);
> + if (prog && !xdp_validate_mtu(priv, net_dev->mtu))
> return -EINVAL;
> - }
>
> up = netif_running(net_dev);
>
> @@ -2870,6 +2891,7 @@ static int dpaa_ioctl(struct net_device *net_dev,
> struct ifreq *rq, int cmd)
> .ndo_set_rx_mode = dpaa_set_rx_mode,
> .ndo_do_ioctl = dpaa_ioctl,
> .ndo_setup_tc = dpaa_setup_tc,
> + .ndo_change_mtu = dpaa_change_mtu,
> .ndo_bpf = dpaa_xdp,
> };
>
> --
> 1.9.1
>
