ovpn: store tunnel and transport statistics

Byte/packet counters for in-tunnel and transport streams
are now initialized and updated as needed.

To be exported via netlink.

Signed-off-by: Antonio Quartulli <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Reviewed-by: Sabrina Dubroca <[e-mail]>
Tested-by: Oleksandr Natalenko <[e-mail]>
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/net/ovpn/Makefile

···
 ovpn-y += peer.o
 ovpn-y += pktid.o
 ovpn-y += socket.o
+ovpn-y += stats.o
 ovpn-y += udp.o

drivers/net/ovpn/io.c

···
 #include <linux/skbuff.h>
 #include <net/gro_cells.h>
 #include <net/gso.h>
+#include <net/ip.h>
 
 #include "ovpnpriv.h"
 #include "peer.h"
···
 	/* cause packet to be "received" by the interface */
 	pkt_len = skb->len;
 	ret = gro_cells_receive(&peer->ovpn->gro_cells, skb);
-	if (likely(ret == NET_RX_SUCCESS))
+	if (likely(ret == NET_RX_SUCCESS)) {
 		/* update RX stats with the size of decrypted packet */
+		ovpn_peer_stats_increment_rx(&peer->vpn_stats, pkt_len);
 		dev_dstats_rx_add(peer->ovpn->dev, pkt_len);
+	}
 }
 
 void ovpn_decrypt_post(void *data, int ret)
···
 	struct ovpn_crypto_key_slot *ks;
 	u8 key_id;
 
+	ovpn_peer_stats_increment_rx(&peer->link_stats, skb->len);
+
 	/* get the key slot matching the key ID in the received packet */
 	key_id = ovpn_key_id_from_skb(skb);
 	ks = ovpn_crypto_key_id_to_slot(&peer->crypto, key_id);
···
 	struct sk_buff *skb = data;
 	struct ovpn_socket *sock;
 	struct ovpn_peer *peer;
+	unsigned int orig_len;
 
 	/* encryption is happening asynchronously. This function will be
 	 * called later by the crypto callback with a proper return value
···
 		goto err;
 
 	skb_mark_not_on_list(skb);
+	orig_len = skb->len;
 
 	rcu_read_lock();
 	sock = rcu_dereference(peer->sock);
···
 		/* no transport configured yet */
 		goto err_unlock;
 	}
+
+	ovpn_peer_stats_increment_tx(&peer->link_stats, orig_len);
 	/* skb passed down the stack - don't free it */
 	skb = NULL;
 err_unlock:
···
 		goto drop;
 	}
 
+	ovpn_peer_stats_increment_tx(&peer->vpn_stats, skb->len);
 	ovpn_send(ovpn, skb_list.next, peer);
 
 	return NETDEV_TX_OK;

drivers/net/ovpn/peer.c

···
 	ovpn_crypto_state_init(&peer->crypto);
 	spin_lock_init(&peer->lock);
 	kref_init(&peer->refcount);
+	ovpn_peer_stats_init(&peer->vpn_stats);
+	ovpn_peer_stats_init(&peer->link_stats);
 
 	ret = dst_cache_init(&peer->dst_cache, GFP_KERNEL);
 	if (ret < 0) {

drivers/net/ovpn/peer.h

···
 
 #include "crypto.h"
 #include "socket.h"
+#include "stats.h"
 
 /**
  * struct ovpn_peer - the main remote peer object
···
  * @crypto: the crypto configuration (ciphers, keys, etc..)
  * @dst_cache: cache for dst_entry used to send to peer
  * @bind: remote peer binding
+ * @vpn_stats: per-peer in-VPN TX/RX stats
+ * @link_stats: per-peer link/transport TX/RX stats
  * @delete_reason: why peer was deleted (i.e. timeout, transport error, ..)
  * @lock: protects binding to peer (bind)
  * @refcount: reference counter
···
 	struct ovpn_crypto_state crypto;
 	struct dst_cache dst_cache;
 	struct ovpn_bind __rcu *bind;
+	struct ovpn_peer_stats vpn_stats;
+	struct ovpn_peer_stats link_stats;
 	enum ovpn_del_peer_reason delete_reason;
 	spinlock_t lock; /* protects bind */
 	struct kref refcount;

drivers/net/ovpn/stats.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*  OpenVPN data channel offload
+ *
+ *  Copyright (C) 2020-2025 OpenVPN, Inc.
+ *
+ *  Author:	James Yonan <[e-mail]>
+ *		Antonio Quartulli <[e-mail]>
+ */
+
+#include <linux/atomic.h>
+
+#include "stats.h"
+
+void ovpn_peer_stats_init(struct ovpn_peer_stats *ps)
+{
+	atomic64_set(&ps->rx.bytes, 0);
+	atomic64_set(&ps->rx.packets, 0);
+
+	atomic64_set(&ps->tx.bytes, 0);
+	atomic64_set(&ps->tx.packets, 0);
+}

drivers/net/ovpn/stats.h

···
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*  OpenVPN data channel offload
+ *
+ *  Copyright (C) 2020-2025 OpenVPN, Inc.
+ *
+ *  Author:	James Yonan <[e-mail]>
+ *		Antonio Quartulli <[e-mail]>
+ *		Lev Stipakov <[e-mail]>
+ */
+
+#ifndef _NET_OVPN_OVPNSTATS_H_
+#define _NET_OVPN_OVPNSTATS_H_
+
+/* one stat */
+struct ovpn_peer_stat {
+	atomic64_t bytes;
+	atomic64_t packets;
+};
+
+/* rx and tx stats combined */
+struct ovpn_peer_stats {
+	struct ovpn_peer_stat rx;
+	struct ovpn_peer_stat tx;
+};
+
+void ovpn_peer_stats_init(struct ovpn_peer_stats *ps);
+
+static inline void ovpn_peer_stats_increment(struct ovpn_peer_stat *stat,
+					     const unsigned int n)
+{
+	atomic64_add(n, &stat->bytes);
+	atomic64_inc(&stat->packets);
+}
+
+static inline void ovpn_peer_stats_increment_rx(struct ovpn_peer_stats *stats,
+						const unsigned int n)
+{
+	ovpn_peer_stats_increment(&stats->rx, n);
+}
+
+static inline void ovpn_peer_stats_increment_tx(struct ovpn_peer_stats *stats,
+						const unsigned int n)
+{
+	ovpn_peer_stats_increment(&stats->tx, n);
+}
+
+#endif /* _NET_OVPN_OVPNSTATS_H_ */