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From:   Menglong Dong <menglong8.dong@gmail.com>
Date:   Thu, 17 Mar 2022 14:02:49 +0800
Message-ID: <CADxym3Zqy1mQnRm5Ec9AfGy=abn0F1WJ_NSgxg-aqTWmKn=Qig@mail.gmail.com>
Subject: Re: [PATCH net-next v3 3/3] net: icmp: add reasons of the skb drops
 to icmp protocol
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     David Ahern <dsahern@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>, xeb@mail.ru,
        David Miller <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Menglong Dong <imagedong@tencent.com>,
        Eric Dumazet <edumazet@google.com>, Martin Lau <kafai@fb.com>,
        Talal Ahmad <talalahmad@google.com>,
        Kees Cook <keescook@chromium.org>,
        Alexander Lobakin <alobakin@pm.me>,
        Hao Peng <flyingpeng@tencent.com>,
        Mengen Sun <mengensun@tencent.com>, dongli.zhang@oracle.com,
        LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        Biao Jiang <benbjiang@tencent.com>
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On Thu, Mar 17, 2022 at 12:05 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 16 Mar 2022 21:35:47 -0600 David Ahern wrote:
> > On 3/16/22 9:18 PM, Jakub Kicinski wrote:
> > >
> > > I guess this set raises the follow up question to Dave if adding
> > > drop reasons to places with MIB exception stats means improving
> > > the granularity or one MIB stat == one reason?
> >
> > There are a few examples where multiple MIB stats are bumped on a drop,
> > but the reason code should always be set based on first failure. Did you
> > mean something else with your question?
>
> I meant whether we want to differentiate between TYPE, and BROADCAST or
> whatever other possible invalid protocol cases we can get here or just
> dump them all into a single protocol error code.

Such as a SKB_DROP_REASON_PROTO_NOTSUPPORTED? and apply
it to 'GRE_VERSION' such cases too? Which means the data is not supported
by current protocol.