On Thu, 21 Sep 2017 21:32:02 +0800
Zhang Shengju <zhangshen...@cmss.chinamobile.com> wrote:
> Currently, any mtu value can be assigned when adding a new ifb device:
> [~]# ip link add name ifb2 mtu 100000 type ifb
> [~]# ip link show ifb2
> 18: ifb2: <BROADCAST,NOARP> mtu 100000 qdisc noop state DOWN mode DEFAULT
> group default qlen 32
> link/ether 7a:bf:f4:63:da:d1 brd ff:ff:ff:ff:ff:ff
>
> This patch adds device MTU validation check.
>
> Signed-off-by: Zhang Shengju <zhangshen...@cmss.chinamobile.com>
> ---
> drivers/net/ifb.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
> index 8870bd2..ce84ad2 100644
> --- a/drivers/net/ifb.c
> +++ b/drivers/net/ifb.c
> @@ -282,6 +282,14 @@ static int ifb_validate(struct nlattr *tb[], struct
> nlattr *data[],
> if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
> return -EADDRNOTAVAIL;
> }
> +
> + if (tb[IFLA_MTU]) {
> + u32 mtu = nla_get_u32(tb[IFLA_MTU]);
> +
> + if (mtu < ETH_MIN_MTU || mtu > ETH_DATA_LEN)
> + return -EINVAL;
> + }
> +
> return 0;
> }
>
What about running ifb with packets coming from devices with jumbo frames?
Also since ifb is an input only device, MTU doesn't matter.
