From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Zhiyuan Hou <zhiyuan2048@linux.alibaba.com>,
Jamal Hadi Salim <jhs@mojatatu.com>,
Cong Wang <xiyou.wangcong@gmail.com>,
Jiri Pirko <jiri@resnulli.us>,
"David S . Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] net: sched: act_mirred: drop skb's dst_entry in ingress redirection
Date: Sat, 12 Oct 2019 22:34:50 +0300 [thread overview]
Message-ID: <2ad15b96-156d-7b71-0e37-74ceeacade35@cogentembedded.com> (raw)
In-Reply-To: <20191012071620.8595-1-zhiyuan2048@linux.alibaba.com>
Hello!
On 10/12/2019 10:16 AM, Zhiyuan Hou wrote:
> In act_mirred's ingress redirection, if the skb's dst_entry is valid
> when call function netif_receive_skb, the fllowing l3 stack process
Following or flowing?
> (ip_rcv_finish_core) will check dst_entry and skip the routing
> decision. Using the old dst_entry is unexpected and may discard the
> skb in some case. For example dst->dst_input points to dst_discard.
>
> This patch drops the skb's dst_entry before calling netif_receive_skb
> so that the skb can be made routing decision like a normal ingress
> skb.
>
> Signed-off-by: Zhiyuan Hou <zhiyuan2048@linux.alibaba.com>
> ---
> net/sched/act_mirred.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
> index 9ce073a05414..6108a64c0cd5 100644
> --- a/net/sched/act_mirred.c
> +++ b/net/sched/act_mirred.c
[...]
> @@ -298,8 +299,10 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
>
> if (!want_ingress)
> err = dev_queue_xmit(skb2);
> - else
> + else {
> + skb_dst_drop(skb2);
> err = netif_receive_skb(skb2);
> + }
If you introduce {} in one *if* branch, {} should be added to the other branches as well,
says CodingStyle.
[...]
MBR, Sergei
next prev parent reply other threads:[~2019-10-12 19:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-12 7:16 [PATCH net] net: sched: act_mirred: drop skb's dst_entry in ingress redirection Zhiyuan Hou
2019-10-12 10:59 ` Eric Dumazet
2019-10-14 7:07 ` Zhiyuan Hou
2019-10-14 12:46 ` Eric Dumazet
2019-10-17 16:08 ` Zhiyuan Hou
2019-10-12 19:34 ` Sergei Shtylyov [this message]
2019-10-14 7:08 ` Zhiyuan Hou
2019-10-14 17:57 ` Cong Wang
2019-10-15 17:22 ` Zhiyuan Hou
2019-10-16 12:13 ` Eyal Birger
2019-10-17 16:33 ` Zhiyuan Hou
2019-10-18 21:25 ` Eyal Birger
2019-10-21 13:06 ` Zhiyuan Hou
2019-10-21 20:50 ` Cong Wang
2019-10-22 10:37 ` Eyal Birger
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