Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
Subject: Re: [PATCH net] veth: Fix RX stats for bpf_redirect_peer() traffic
To:     Peilin Ye <yepeilin.cs@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>,
        Yonghong Song <yonghong.song@linux.dev>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        Jesper Dangaard Brouer <hawk@kernel.org>
Cc:     Peilin Ye <peilin.ye@bytedance.com>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        Cong Wang <cong.wang@bytedance.com>,
        Jiang Wang <jiang.wang@bytedance.com>,
        Youlun Zhang <zhangyoulun@bytedance.com>
References: <20231027184657.83978-1-yepeilin.cs@gmail.com>
 <20231027190254.GA88444@n191-129-154.byted.org>
From:   Daniel Borkmann <daniel@iogearbox.net>
Message-ID: <59be18ff-dabc-2a07-3d78-039461b0f3f7@iogearbox.net>
Date:   Sat, 28 Oct 2023 09:06:44 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.7.2
MIME-Version: 1.0
In-Reply-To: <20231027190254.GA88444@n191-129-154.byted.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Peilin,

On 10/27/23 9:02 PM, Peilin Ye wrote:
> On Fri, Oct 27, 2023 at 06:46:57PM +0000, Peilin Ye wrote:
>> diff --git a/net/core/filter.c b/net/core/filter.c
>> index 21d75108c2e9..7aca28b7d0fd 100644
>> --- a/net/core/filter.c
>> +++ b/net/core/filter.c
>> @@ -2492,6 +2492,7 @@ int skb_do_redirect(struct sk_buff *skb)
>>   			     net_eq(net, dev_net(dev))))
>>   			goto out_drop;
>>   		skb->dev = dev;
>> +		dev_sw_netstats_rx_add(dev, skb->len);
> 
> This assumes that all devices that support BPF_F_PEER (currently only
> veth) use tstats (instead of lstats, or dstats) - is that okay?

Dumb question, but why all this change and not simply just call ...

   dev_lstats_add(dev, skb->len)

... on the host dev ?

> If not, should I add another NDO e.g. ->ndo_stats_rx_add()?

Definitely no new stats ndo resp indirect call in fast path.

Thanks,
Daniel