Re: [PATCH net-next v11 09/23] ovpn: implement basic RX path (UDP)

[Sergey Ryazanov <ryazanov.s.a@xxxxxxxxx>]

On 29.10.2024 12:47, Antonio Quartulli wrote:
> +static void ovpn_netdev_write(struct ovpn_peer *peer, struct sk_buff *skb)
> +{
> +	unsigned int pkt_len;
> +
> +	/* we can't guarantee the packet wasn't corrupted before entering the
> +	 * VPN, therefore we give other layers a chance to check that
> +	 */
> +	skb->ip_summed = CHECKSUM_NONE;
> +
> +	/* skb hash for transport packet no longer valid after decapsulation */
> +	skb_clear_hash(skb);
> +
> +	/* post-decrypt scrub -- prepare to inject encapsulated packet onto the
> +	 * interface, based on __skb_tunnel_rx() in dst.h
> +	 */
> +	skb->dev = peer->ovpn->dev;
> +	skb_set_queue_mapping(skb, 0);
> +	skb_scrub_packet(skb, true);
> +
> +	skb_reset_network_header(skb);
> +	skb_reset_transport_header(skb);
> +	skb_probe_transport_header(skb);
> +	skb_reset_inner_headers(skb);
> +
> +	memset(skb->cb, 0, sizeof(skb->cb));
> +
> +	/* cause packet to be "received" by the interface */
> +	pkt_len = skb->len;
> +	if (likely(gro_cells_receive(&peer->ovpn->gro_cells,
> +				     skb) == NET_RX_SUCCESS))

nit: to improve readability, the packet delivery call can be composed 
like this:

      pkt_len = skb->len;
      res = gro_cells_receive(&peer->ovpn->gro_cells, skb);
      if (likely(res == NET_RX_SUCCESS))

> +		/* update RX stats with the size of decrypted packet */
> +		dev_sw_netstats_rx_add(peer->ovpn->dev, pkt_len);
> +}