[PATCH net-next v3 3/3] net: ovpn: use new noref xmit flow in ovpn_udp{4,6}_output
From: Marek Mietus <hidden>
Date: 2025-09-22 11:18:07
Subsystem:
networking drivers, openvpn data channel offload, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Antonio Quartulli, Linus Torvalds
ovpn_udp{4,6}_output unnecessarily references the dst_entry from
the dst_cache.
Reduce this overhead by using the newly implemented
udp_tunnel{,6}_xmit_skb_noref function and dst_cache helpers.
These changes are safe as both ipv4 and ip6 support noref xmit under RCU
which is already the case for ovpn.
Signed-off-by: Marek Mietus <redacted>
---
drivers/net/ovpn/udp.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ovpn/udp.c b/drivers/net/ovpn/udp.c
index d6a0f7a0b75d..917cd308a7f4 100644
--- a/drivers/net/ovpn/udp.c
+++ b/drivers/net/ovpn/udp.c@@ -158,7 +158,7 @@ static int ovpn_udp4_output(struct ovpn_peer *peer, struct ovpn_bind *bind, int ret; local_bh_disable(); - rt = dst_cache_get_ip4(cache, &fl.saddr); + rt = dst_cache_get_ip4_rcu(cache, &fl.saddr); if (rt) goto transmit;
@@ -194,12 +194,12 @@ static int ovpn_udp4_output(struct ovpn_peer *peer, struct ovpn_bind *bind, ret); goto err; } - dst_cache_set_ip4(cache, &rt->dst, fl.saddr); + dst_cache_steal_ip4(cache, &rt->dst, fl.saddr); transmit: - udp_tunnel_xmit_skb(rt, sk, skb, fl.saddr, fl.daddr, 0, - ip4_dst_hoplimit(&rt->dst), 0, fl.fl4_sport, - fl.fl4_dport, false, sk->sk_no_check_tx, 0); + udp_tunnel_xmit_skb_noref(rt, sk, skb, fl.saddr, fl.daddr, 0, + ip4_dst_hoplimit(&rt->dst), 0, fl.fl4_sport, + fl.fl4_dport, false, sk->sk_no_check_tx, 0); ret = 0; err: local_bh_enable();
@@ -235,7 +235,7 @@ static int ovpn_udp6_output(struct ovpn_peer *peer, struct ovpn_bind *bind, }; local_bh_disable(); - dst = dst_cache_get_ip6(cache, &fl.saddr); + dst = dst_cache_get_ip6_rcu(cache, &fl.saddr); if (dst) goto transmit;
@@ -259,7 +259,7 @@ static int ovpn_udp6_output(struct ovpn_peer *peer, struct ovpn_bind *bind, &bind->remote.in6, ret); goto err; } - dst_cache_set_ip6(cache, dst, &fl.saddr); + dst_cache_steal_ip6(cache, dst, &fl.saddr); transmit: /* user IPv6 packets may be larger than the transport interface
@@ -269,12 +269,12 @@ static int ovpn_udp6_output(struct ovpn_peer *peer, struct ovpn_bind *bind, * fragment packets if needed. * * NOTE: this is not needed for IPv4 because we pass df=0 to - * udp_tunnel_xmit_skb() + * udp_tunnel_xmit_skb_noref() */ skb->ignore_df = 1; - udp_tunnel6_xmit_skb(dst, sk, skb, skb->dev, &fl.saddr, &fl.daddr, 0, - ip6_dst_hoplimit(dst), 0, fl.fl6_sport, - fl.fl6_dport, udp_get_no_check6_tx(sk), 0); + udp_tunnel6_xmit_skb_noref(dst, sk, skb, skb->dev, &fl.saddr, &fl.daddr, 0, + ip6_dst_hoplimit(dst), 0, fl.fl6_sport, + fl.fl6_dport, udp_get_no_check6_tx(sk), 0); ret = 0; err: local_bh_enable();
--
2.51.0