From: Zhiyuan Hou <zhiyuan2048@linux.alibaba.com>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded.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: Mon, 14 Oct 2019 15:08:54 +0800 [thread overview]
Message-ID: <20b0aafe-4c1c-1c7a-5563-56eb43ebb409@linux.alibaba.com> (raw)
In-Reply-To: <2ad15b96-156d-7b71-0e37-74ceeacade35@cogentembedded.com>
On 2019/10/13 3:34 上午, Sergei Shtylyov wrote:
> 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?
Sorry, it should be following. I will change it in next version.
>> (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.
I will change it in next version . Thanks.
> [...]
>
> MBR, Sergei
next prev parent reply other threads:[~2019-10-14 7:09 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
2019-10-14 7:08 ` Zhiyuan Hou [this message]
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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