Re: [PATCH net-next v6] ipv6: add `force_forwarding` sysctl to enable per-interface forwarding

[Gabriel Goller]

On 15.07.2025 15:34, Paolo Abeni wrote:
> On 7/11/25 2:42 PM, Gabriel Goller wrote:
> > It is currently impossible to enable ipv6 forwarding on a per-interface
> > basis like in ipv4. To enable forwarding on an ipv6 interface we need to
> > enable it on all interfaces and disable it on the other interfaces using
> > a netfilter rule. This is especially cumbersome if you have lots of
> > interface and only want to enable forwarding on a few. According to the
> > sysctl docs [0] the `net.ipv6.conf.all.forwarding` enables forwarding
> > for all interfaces, while the interface-specific
> > `net.ipv6.conf.<interface>.forwarding` configures the interface
> > Host/Router configuration.
> >
> > Introduce a new sysctl flag `force_forwarding`, which can be set on every
> > interface. The ip6_forwarding function will then check if the global
> > forwarding flag OR the force_forwarding flag is active and forward the
> > packet.
> >
> > To preserver backwards-compatibility reset the flag (on all interfaces)
> > to 0 if the net.ipv6.conf.all.forwarding flag is set to 0.
> >
> > Add a short selftest that checks if a packet gets forwarded with and
> > without `force_forwarding`.
> >
> > [0]: https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
> >
> > Signed-off-by: Gabriel Goller <g.goller@xxxxxxxxxxx>
> > Acked-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
> > ---
> > v6:
> >     * rebase
> >     * remove brackts around single line
> >     * add 'nodad' to addresses in selftest to avoid sporadic failures
>
> I'm sorry, but it still does not apply. Please rebase again and re-submit.
>
> Thanks,
>
> Paolo

Thanks for the review! Rebased again, should apply now.