Re: [RFC ovpn net-next 1/5] ovpn: add multicast/braodcast packet transmission support

Hi,

On 14/05/2026 11:52, Marco Baffo wrote:
> The ovpn DCO driver currently drops all multicast/broadcast packets
> because it does not set IFF_MULTICAST and IFF_BROADCAST on the
> netdevice and always performs a unicast peer lookup in ovpn_net_xmit().
> This prevents multicast routing daemons such as smcroute from using an
> ovpn interface as a multicast VIF and makes it impossible to
> forward multicastand broadcast traffic to VPN clients.
> 
> Add the minimal infrastructure needed to get multicast/broadcast working:
> 
> - Set IFF_MULTICAST and IFF_BROADCAST in ovpn_setup().
> 
> - Detect multicast and broadcast destinations in
>    ovpn_peer_list_get_by_dst() and create a list with the target peers.
> 
> - Introduce ovpn_skb_list_clone() to clone GSO segment lists and
>    replicate the packet to every connected peer in
>    ovpn_net_xmit().
> 
> For now multicast traffic is flooded to all peers. A future
> enhancement will replace the flood with a subscription table driven by
> IGMP snooping.
> 
> Signed-off-by: Marco Baffo <[email protected]>

As discussed on IRC, we will move forward only with the first patch of 
this batch.

The rest is not going to be further developed as we concluded there is 
not much traction for such feature nowadays.

Regards,


-- 
Antonio Quartulli