[PATCH net-next v5 18/25] ovpn: add support for updating local UDP endpoint
From: Antonio Quartulli <antonio@openvpn.net>
Date: 2024-06-27 13:08:15
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
In case of UDP links, the local endpoint used to communicate with a given peer may change without a connection restart. Add support for learning the new address in case of change. Signed-off-by: Antonio Quartulli <antonio@openvpn.net> --- drivers/net/ovpn/io.c | 5 +++++ drivers/net/ovpn/peer.c | 42 +++++++++++++++++++++++++++++++++++++++++ drivers/net/ovpn/peer.h | 3 +++ 3 files changed, 50 insertions(+)
diff --git a/drivers/net/ovpn/io.c b/drivers/net/ovpn/io.c
index dedc4d4a1c72..9188afe0f47e 100644
--- a/drivers/net/ovpn/io.c
+++ b/drivers/net/ovpn/io.c@@ -119,6 +119,11 @@ void ovpn_decrypt_post(struct sk_buff *skb, int ret) /* note event of authenticated packet received for keepalive */ ovpn_peer_keepalive_recv_reset(peer); + if (peer->sock->sock->sk->sk_protocol == IPPROTO_UDP) { + /* update source endpoint for this peer */ + ovpn_peer_update_local_endpoint(peer, skb); + } + /* point to encapsulated IP packet */ __skb_pull(skb, ovpn_skb_cb(skb)->payload_offset);
diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c
index 289fe3f84ed4..ec3064438753 100644
--- a/drivers/net/ovpn/peer.c
+++ b/drivers/net/ovpn/peer.c@@ -455,6 +455,48 @@ struct ovpn_peer *ovpn_peer_get_by_id(struct ovpn_struct *ovpn, u32 peer_id) return peer; } +/** + * ovpn_peer_update_local_endpoint - update local endpoint for peer + * @peer: peer to update the endpoint for + * @skb: incoming packet to retrieve the destination address (local) from + */ +void ovpn_peer_update_local_endpoint(struct ovpn_peer *peer, + struct sk_buff *skb) +{ + struct ovpn_bind *bind; + + rcu_read_lock(); + bind = rcu_dereference(peer->bind); + if (unlikely(!bind)) + goto unlock; + + switch (skb_protocol_to_family(skb)) { + case AF_INET: + if (unlikely(bind->local.ipv4.s_addr != ip_hdr(skb)->daddr)) { + netdev_dbg(peer->ovpn->dev, + "%s: learning local IPv4 for peer %d (%pI4 -> %pI4)\n", + __func__, peer->id, &bind->local.ipv4.s_addr, + &ip_hdr(skb)->daddr); + bind->local.ipv4.s_addr = ip_hdr(skb)->daddr; + } + break; + case AF_INET6: + if (unlikely(memcmp(&bind->local.ipv6, &ipv6_hdr(skb)->daddr, + sizeof(bind->local.ipv6)))) { + netdev_dbg(peer->ovpn->dev, + "%s: learning local IPv6 for peer %d (%pI6c -> %pI6c\n", + __func__, peer->id, &bind->local.ipv6, + &ipv6_hdr(skb)->daddr); + bind->local.ipv6 = ipv6_hdr(skb)->daddr; + } + break; + default: + break; + } +unlock: + rcu_read_unlock(); +} + /** * ovpn_peer_get_by_dst - Lookup peer to send skb to * @ovpn: the private data representing the current VPN session
diff --git a/drivers/net/ovpn/peer.h b/drivers/net/ovpn/peer.h
index fd7e9d57b38a..1f12ba141d80 100644
--- a/drivers/net/ovpn/peer.h
+++ b/drivers/net/ovpn/peer.h@@ -189,4 +189,7 @@ static inline void ovpn_peer_keepalive_xmit_reset(struct ovpn_peer *peer) void ovpn_peer_keepalive_set(struct ovpn_peer *peer, u32 interval, u32 timeout); +void ovpn_peer_update_local_endpoint(struct ovpn_peer *peer, + struct sk_buff *skb); + #endif /* _NET_OVPN_OVPNPEER_H_ */
--
2.44.2