On 30/10/2024 18:14, Sabrina Dubroca wrote:

2024-10-29, 11:47:21 +0100, Antonio Quartulli wrote:

quoted

+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.

ACK

quoted

+		if (unlikely(!ovpn_encrypt_one(peer, curr))) {
+			dev_core_stats_tx_dropped_inc(ovpn->dev);
+			kfree_skb(curr);
+		}

quoted

+void ovpn_udp_send_skb(struct ovpn_struct *ovpn, struct ovpn_peer *peer,
+		       struct sk_buff *skb)
+{

[...]

quoted

+	/* 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

Right. This means we can remove that call to tx_add().

failure it increments a different tx_dropped counter than what
dev_core_stats_tx_dropped_inc, but they should get summed in the end.

It seems they are summed up in dev_get_tstats64(), therefore I should 
remove the tx_dropped_inc() call to avoid double counting.

Thanks!

Cheers,

quoted

+}

-- 
Antonio Quartulli
OpenVPN Inc.