Re: [PATCH v2 1/2] ip_tunnel: fix ip tunnel lookup in collect_md mode

[Pravin Shelar]

On Fri, Jun 16, 2017 at 8:27 PM, Haishuang Yan
<yanhaishuang@xxxxxxxxxxxxxxxxxxxx> wrote:
> In collect_md mode, if the tun dev is down, it still can call
> ip_tunnel_rcv to receive on packets, and the rx statistics increase
> improperly.
>
> Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.")
> Cc: Pravin B Shelar <pshelar@xxxxxxxxxx>
> Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
>
> ---
> Change since v2:
>   * Fix wrong recipient addresss
> ---
>  net/ipv4/ip_tunnel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
> index 0f1d876..a3caba1 100644
> --- a/net/ipv4/ip_tunnel.c
> +++ b/net/ipv4/ip_tunnel.c
> @@ -176,7 +176,7 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
>                 return cand;
>
>         t = rcu_dereference(itn->collect_md_tun);
> -       if (t)
> +       if (t && (t->dev->flags & IFF_UP))
>                 return t;
>
It would be nice if we could increment drop count if tunnel device is not up.