Re: [PATCH net-next] icmp: pass RFC 8335 reply messages to ping_rcv

[Andreas Roeseler <andreas.a.roeseler@gmail.com>]

On Mon, 2021-04-12 at 15:28 -0400, Willem de Bruijn wrote:
> On Mon, Apr 12, 2021 at 3:09 PM Andreas Roeseler
> <andreas.a.roeseler@gmail.com> wrote:
> > 
> > The current icmp_rcv function drops all unknown ICMP types,
> > including
> > ICMP_EXT_ECHOREPLY (type 43). In order to parse Extended Echo Reply
> > messages, we have
> > to pass these packets to the ping_rcv function, which does not do
> > any
> > other filtering and passes the packet to the designated socket.
> > 
> > Pass incoming RFC 8335 ICMP Extended Echo Reply packets to the
> > ping_rcv
> > handler instead of discarding the packet.
> > 
> > Signed-off-by: Andreas Roeseler <andreas.a.roeseler@gmail.com>
> > ---
> >  net/ipv4/icmp.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
> > index 76990e13a2f9..8bd988fbcb31 100644
> > --- a/net/ipv4/icmp.c
> > +++ b/net/ipv4/icmp.c
> > @@ -1196,6 +1196,11 @@ int icmp_rcv(struct sk_buff *skb)
> >                 goto success_check;
> >         }
> > 
> > +       if (icmph->type == ICMP_EXT_ECHOREPLY) {
> > +               success = ping_rcv(skb);
> > +               goto success_check;
> > +       }
> > +
> 
> Do you need the same for ICMPV6_EXT_ECHO_REPLY ?

Yes, but this should be handled in icmpv6_rcv in net/ipv6/icmp.c and
we're thinking of including all icmpv6 support for RFC 8335 (replying
and parsing replies) in a separate patch.