[PATCH net 1/3] ovpn: propagate socket mark to skb in UDP

Antonio Quartulli
2025-07-03T11:46:00Z

From: Ralf Lici <ralf@mandelbit.com>

OpenVPN allows users to configure a FW mark on sockets used to
communicate with other peers. The mark is set by means of the
`SO_MARK` Linux socket option.

However, in the ovpn UDP code path, the socket's `sk_mark` value is
currently ignored and it is not propagated to outgoing `skbs`.

This commit ensures proper inheritance of the field by setting
`skb->mark` to `sk->sk_mark` before handing the `skb` to the network
stack for transmission.

Signed-off-by: Ralf Lici <ralf@mandelbit.com>
Link: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg31877.html
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
---
drivers/net/ovpn/udp.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/ovpn/udp.c b/drivers/net/ovpn/udp.c
index bff00946eae2..60435a21f29c 100644
--- a/drivers/net/ovpn/udp.c
+++ b/drivers/net/ovpn/udp.c
@@ -344,6 +344,7 @@ void ovpn_udp_send_skb(struct ovpn_peer *peer, struct sock *sk,
int ret;

skb->dev = peer->ovpn->dev;
+ skb->mark = READ_ONCE(sk->sk_mark);
/* no checksum performed at this layer */
skb->ip_summed = CHECKSUM_NONE;

--
2.49.0