Re: [PATCH net-next v18 20/25] ovpn: implement peer add/get/dump/delete via netlink

[Antonio Quartulli]

On 20/01/2025 15:52, Antonio Quartulli wrote:
> On 17/01/2025 12:48, Sabrina Dubroca wrote:
> [...]
> > -------- 8< --------
> >
> > diff --git a/drivers/net/ovpn/netlink.c b/drivers/net/ovpn/netlink.c
> > index 72357bb5f30b..19aa4ee6d468 100644
> > --- a/drivers/net/ovpn/netlink.c
> > +++ b/drivers/net/ovpn/netlink.c
> > @@ -733,6 +733,9 @@ int ovpn_nl_peer_del_doit(struct sk_buff *skb, 
> > struct genl_info *info)
> >       netdev_dbg(ovpn->dev, "del peer %u\n", peer->id);
> >       ret = ovpn_peer_del(peer, OVPN_DEL_PEER_REASON_USERSPACE);
> > +    if (ret >= 0 && peer->sock)
> > +        wait_for_completion(&peer->sock_detach);
> > +
> >       ovpn_peer_put(peer);
> >       return ret;
> > diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c
> > index b032390047fe..6120521d0c32 100644
> > --- a/drivers/net/ovpn/peer.c
> > +++ b/drivers/net/ovpn/peer.c
> > @@ -92,6 +92,7 @@ struct ovpn_peer *ovpn_peer_new(struct ovpn_priv 
> > *ovpn, u32 id)
> >       ovpn_peer_stats_init(&peer->vpn_stats);
> >       ovpn_peer_stats_init(&peer->link_stats);
> >       INIT_WORK(&peer->keepalive_work, ovpn_peer_keepalive_send);
> > +    init_completion(&peer->sock_detach);
> >       ret = dst_cache_init(&peer->dst_cache, GFP_KERNEL);
> >       if (ret < 0) {
> > diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h
> > index 7a062cc5a5a4..8c54bf5709ef 100644
> > --- a/drivers/net/ovpn/peer.h
> > +++ b/drivers/net/ovpn/peer.h
> > @@ -112,6 +112,7 @@ struct ovpn_peer {
> >       struct rcu_head rcu;
> >       struct work_struct remove_work;
> >       struct work_struct keepalive_work;
> > +    struct completion sock_detach;
> >   };
> >   /**
> > diff --git a/drivers/net/ovpn/socket.c b/drivers/net/ovpn/socket.c
> > index a5c3bc834a35..7cefac42c3be 100644
> > --- a/drivers/net/ovpn/socket.c
> > +++ b/drivers/net/ovpn/socket.c
> > @@ -31,6 +31,8 @@ static void ovpn_socket_release_kref(struct kref *kref)
> >       sockfd_put(sock->sock);
> >       kfree_rcu(sock, rcu);
> > +
> > +    complete(&sock->peer->sock_detach);

I am moving this line to ovpn_socket_put(), right after kref_put() so 
that every peer going through the socket release will get their 
complete() invoked.

If the peer happens to be the last one owning the socket, kref_put() 
will first do the detach and only then complete() gets called.

This requires ovpn_socket_release/put() to take the peer as argument, 
but that's ok.

This way we should achieve what we needed.


Regards,


--
Antonio Quartulli
OpenVPN Inc.