2025-03-18, 02:40:42 +0100, Antonio Quartulli wrote:
> +static int ovpn_udp_output(struct ovpn_peer *peer, struct dst_cache *cache,
> + struct sock *sk, struct sk_buff *skb)
> +{
> + struct ovpn_bind *bind;
> + int ret;
> +
> + /* set sk to null if skb is already orphaned */
> + if (!skb->destructor)
> + skb->sk = NULL;
> +
> + /* always permit openvpn-created packets to be (outside) fragmented */
> + skb->ignore_df = 1;
Have you tested this with IPv4 encap? AFAICT it doesn't have any
effect because of the call chain:
ovpn_udp4_output -> udp_tunnel_xmit_skb -> iptunnel_xmit -> skb_scrub_packet
which does
skb->ignore_df = 0;
But since you pass df = 0 to udp_tunnel_xmit_skb, I suspect it works
as intended despite skb_scrub_packet.
[note: that was the last comment I wanted to send, I have a few more
suggestions that don't need to be addressed at this time]
> +
> + rcu_read_lock();
> + bind = rcu_dereference(peer->bind);
> + if (unlikely(!bind)) {
> + net_warn_ratelimited("%s: no bind for remote peer %u\n",
> + netdev_name(peer->ovpn->dev), peer->id);
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + switch (bind->remote.in4.sin_family) {
> + case AF_INET:
> + ret = ovpn_udp4_output(peer, bind, cache, sk, skb);
> + break;
> +#if IS_ENABLED(CONFIG_IPV6)
> + case AF_INET6:
> + ret = ovpn_udp6_output(peer, bind, cache, sk, skb);
> + break;
> +#endif
> + default:
> + ret = -EAFNOSUPPORT;
> + break;
> + }
> +
> +out:
> + rcu_read_unlock();
> + return ret;
> +}
--
Sabrina
