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) { + 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