Re: [PATCH net-next 2/2] ipv6: fix blackhole routes

[Stanislav Fomichev <stfomichev@gmail.com>]

On 02/12, Eric Dumazet wrote:
> On Wed, Feb 12, 2025 at 7:00 PM David Ahern <dsahern@kernel.org> wrote:
> >
> > On 2/12/25 9:43 AM, Eric Dumazet wrote:
> > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> > > index 78362822b9070df138a0724dc76003b63026f9e2..335cdbfe621e2fc4a71badf4ff834870638d5e13 100644
> > > --- a/net/ipv6/route.c
> > > +++ b/net/ipv6/route.c
> > > @@ -1048,7 +1048,7 @@ static const int fib6_prop[RTN_MAX + 1] = {
> > >       [RTN_BROADCAST] = 0,
> > >       [RTN_ANYCAST]   = 0,
> > >       [RTN_MULTICAST] = 0,
> > > -     [RTN_BLACKHOLE] = -EINVAL,
> > > +     [RTN_BLACKHOLE] = 0,
> > >       [RTN_UNREACHABLE] = -EHOSTUNREACH,
> > >       [RTN_PROHIBIT]  = -EACCES,
> > >       [RTN_THROW]     = -EAGAIN,
> >
> > EINVAL goes back to ef2c7d7b59708 in 2012, so this is a change in user
> > visible behavior. Also this will make ipv6 deviate from ipv4:
> >
> >         [RTN_BLACKHOLE] = {
> >                 .error  = -EINVAL,
> >                 .scope  = RT_SCOPE_UNIVERSE,
> >         },
> 
> Should we create a new RTN_SINK (or different name), for both IPv4 and IPv6 ?

Sorry for sidelining, but depending on how this discussion goes,
tools/testing/selftests/net/fib_nexthops.sh test might need to be
adjusted (currently fails presumably because of -EINVAL change):

https://netdev-3.bots.linux.dev/vmksft-net/results/990081/2-fib-nexthops-sh/stdout

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