Re: [PATCH net-next v11 08/23] ovpn: implement basic TX path (UDP)
From: Sabrina Dubroca
Date: Wed Oct 30 2024 - 13:19:55 EST
2024-10-29, 11:47:21 +0100, Antonio Quartulli wrote:
> +static void ovpn_send(struct ovpn_struct *ovpn, struct sk_buff *skb,
> + struct ovpn_peer *peer)
> +{
> + struct sk_buff *curr, *next;
> +
> + if (likely(!peer))
> + /* retrieve peer serving the destination IP of this packet */
> + peer = ovpn_peer_get_by_dst(ovpn, skb);
> + if (unlikely(!peer)) {
> + net_dbg_ratelimited("%s: no peer to send data to\n",
> + ovpn->dev->name);
> + dev_core_stats_tx_dropped_inc(ovpn->dev);
> + goto drop;
> + }
> +
> + /* this might be a GSO-segmented skb list: process each skb
> + * independently
> + */
> + skb_list_walk_safe(skb, curr, next)
nit (if you end up reposting): there should probably be some braces
around the (multi-line) loop body.
> + if (unlikely(!ovpn_encrypt_one(peer, curr))) {
> + dev_core_stats_tx_dropped_inc(ovpn->dev);
> + kfree_skb(curr);
> + }
> +void ovpn_udp_send_skb(struct ovpn_struct *ovpn, struct ovpn_peer *peer,
> + struct sk_buff *skb)
> +{
[...]
> + /* crypto layer -> transport (UDP) */
> + pkt_len = skb->len;
> + ret = ovpn_udp_output(ovpn, bind, &peer->dst_cache, sock->sk, skb);
> +
> +out_unlock:
> + rcu_read_unlock();
> +out:
> + if (unlikely(ret < 0)) {
> + dev_core_stats_tx_dropped_inc(ovpn->dev);
> + kfree_skb(skb);
> + return;
> + }
> +
> + dev_sw_netstats_tx_add(ovpn->dev, 1, pkt_len);
If I'm following things correctly, that's already been counted:
ovpn_udp_output -> ovpn_udp4_output -> udp_tunnel_xmit_skb
-> iptunnel_xmit
-> iptunnel_xmit_stats
which does (on success) the same thing as dev_sw_netstats_tx_add. On
failure it increments a different tx_dropped counter than what
dev_core_stats_tx_dropped_inc, but they should get summed in the end.
> +}
--
Sabrina