Re: [PATCH v2] tcp: Add listening address to SYN flood message

From: Jamie Bainbridge
Date: Sun Nov 13 2022 - 19:37:59 EST


On Sat, 12 Nov 2022 at 10:14, Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
>
> On Fri, Nov 11, 2022 at 4:11 PM Stephen Hemminger
> <stephen@xxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Sat, 12 Nov 2022 10:59:52 +1100
> > Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx> wrote:
> >
> > > On Sat, 12 Nov 2022 at 04:20, Stephen Hemminger
> > > <stephen@xxxxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > On Fri, 11 Nov 2022 14:59:32 +1100
> > > > Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx> 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.
>
> Note that "ss dst" really needs the [] notation for IPv6
>
> ss -t dst "[::1]"
> State Recv-Q Send-Q
> Local Address:Port Peer Address:Port
> Process
> CLOSE-WAIT 1 0
> [::1]:50584 [::1]:ipp
>
> So we have inconsistency anyway...
>
> As you said, no strong opinion.

Following an RFC and ss filter paste is a good reason, I'll do a v3.

Jamie