Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 11 Nov 2022 16:11:20 -0800
From:   Stephen Hemminger <stephen@networkplumber.org>
To:     Jamie Bainbridge <jamie.bainbridge@gmail.com>
Cc:     Eric Dumazet <edumazet@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] tcp: Add listening address to SYN flood message
Message-ID: <20221111161120.770b9db2@hermes.local>
In-Reply-To: <CAAvyFNhkn2Zv16RMWGCtQh4SpjJX56q8gyEL3Mz6Ru+Ef=SJfA@mail.gmail.com>
References: <7ccd58e8e26bcdd82e66993cbd53ff59eebe3949.1668139105.git.jamie.bainbridge@gmail.com>
        <20221111092047.7d33bcd3@hermes.local>
        <CAAvyFNhkn2Zv16RMWGCtQh4SpjJX56q8gyEL3Mz6Ru+Ef=SJfA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Sat, 12 Nov 2022 10:59:52 +1100
Jamie Bainbridge <jamie.bainbridge@gmail.com> wrote:

> On Sat, 12 Nov 2022 at 04:20, Stephen Hemminger
> <stephen@networkplumber.org> wrote:
> >
> > On Fri, 11 Nov 2022 14:59:32 +1100
> > Jamie Bainbridge <jamie.bainbridge@gmail.com> wrote:
> >  
> > > +         xchg(&queue->synflood_warned, 1) == 0) {
> > > +             if (IS_ENABLED(CONFIG_IPV6) && sk->sk_family == AF_INET6) {
> > > +                     net_info_ratelimited("%s: Possible SYN flooding on port %pI6c.%u. %s.\n",
> > > +                                     proto, &sk->sk_v6_rcv_saddr,
> > > +                                     sk->sk_num, msg);
> > > +             } else {
> > > +                     net_info_ratelimited("%s: Possible SYN flooding on port %pI4.%u. %s.\n",
> > > +                                     proto, &sk->sk_rcv_saddr,
> > > +                                     sk->sk_num, msg);  
> >
> > Minor nit, the standard format for printing addresses would be to use colon seperator before port
> >
> >                 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_family == AF_INET6) {
> >                         net_info_ratelimited("%s: Possible SYN flooding on [%pI6c]:%u. %s.\n",
> >                                         proto, &sk->sk_v6_rcv_saddr, sk->sk_num, msg);
> >                 } else {
> >                         net_info_ratelimited("%s: Possible SYN flooding on %pI4:%u. %s.\n",
> >                                         proto, &sk->sk_rcv_saddr, sk->sk_num, msg);  
> 
> I considered this too, though Eric suggested "IP.port" to match tcpdump.

That works, if it happens I doubt it matters.