ovpn: add basic netlink support

This commit introduces basic netlink support with family
registration/unregistration functionalities and stub pre/post-doit.

More importantly it introduces the YAML uAPI description along
with its auto-generated files:
- include/uapi/linux/ovpn.h
- drivers/net/ovpn/netlink-gen.c
- drivers/net/ovpn/netlink-gen.h

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
Link: https://patch.msgid.link/20250415-b4-ovpn-v26-2-577f6097b964@openvpn.net
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/include/uapi/linux/ovpn.h b/include/uapi/linux/ovpn.h
new file mode 100644
index 000000000000..680d1522dc87
--- /dev/null
+++ b/include/uapi/linux/ovpn.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/ovpn.yaml */
+/* YNL-GEN uapi header */
+
+#ifndef _UAPI_LINUX_OVPN_H
+#define _UAPI_LINUX_OVPN_H
+
+#define OVPN_FAMILY_NAME	"ovpn"
+#define OVPN_FAMILY_VERSION	1
+
+#define OVPN_NONCE_TAIL_SIZE	8
+
+enum ovpn_cipher_alg {
+	OVPN_CIPHER_ALG_NONE,
+	OVPN_CIPHER_ALG_AES_GCM,
+	OVPN_CIPHER_ALG_CHACHA20_POLY1305,
+};
+
+enum ovpn_del_peer_reason {
+	OVPN_DEL_PEER_REASON_TEARDOWN,
+	OVPN_DEL_PEER_REASON_USERSPACE,
+	OVPN_DEL_PEER_REASON_EXPIRED,
+	OVPN_DEL_PEER_REASON_TRANSPORT_ERROR,
+	OVPN_DEL_PEER_REASON_TRANSPORT_DISCONNECT,
+};
+
+enum ovpn_key_slot {
+	OVPN_KEY_SLOT_PRIMARY,
+	OVPN_KEY_SLOT_SECONDARY,
+};
+
+enum {
+	OVPN_A_PEER_ID = 1,
+	OVPN_A_PEER_REMOTE_IPV4,
+	OVPN_A_PEER_REMOTE_IPV6,
+	OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID,
+	OVPN_A_PEER_REMOTE_PORT,
+	OVPN_A_PEER_SOCKET,
+	OVPN_A_PEER_SOCKET_NETNSID,
+	OVPN_A_PEER_VPN_IPV4,
+	OVPN_A_PEER_VPN_IPV6,
+	OVPN_A_PEER_LOCAL_IPV4,
+	OVPN_A_PEER_LOCAL_IPV6,
+	OVPN_A_PEER_LOCAL_PORT,
+	OVPN_A_PEER_KEEPALIVE_INTERVAL,
+	OVPN_A_PEER_KEEPALIVE_TIMEOUT,
+	OVPN_A_PEER_DEL_REASON,
+	OVPN_A_PEER_VPN_RX_BYTES,
+	OVPN_A_PEER_VPN_TX_BYTES,
+	OVPN_A_PEER_VPN_RX_PACKETS,
+	OVPN_A_PEER_VPN_TX_PACKETS,
+	OVPN_A_PEER_LINK_RX_BYTES,
+	OVPN_A_PEER_LINK_TX_BYTES,
+	OVPN_A_PEER_LINK_RX_PACKETS,
+	OVPN_A_PEER_LINK_TX_PACKETS,
+
+	__OVPN_A_PEER_MAX,
+	OVPN_A_PEER_MAX = (__OVPN_A_PEER_MAX - 1)
+};
+
+enum {
+	OVPN_A_KEYCONF_PEER_ID = 1,
+	OVPN_A_KEYCONF_SLOT,
+	OVPN_A_KEYCONF_KEY_ID,
+	OVPN_A_KEYCONF_CIPHER_ALG,
+	OVPN_A_KEYCONF_ENCRYPT_DIR,
+	OVPN_A_KEYCONF_DECRYPT_DIR,
+
+	__OVPN_A_KEYCONF_MAX,
+	OVPN_A_KEYCONF_MAX = (__OVPN_A_KEYCONF_MAX - 1)
+};
+
+enum {
+	OVPN_A_KEYDIR_CIPHER_KEY = 1,
+	OVPN_A_KEYDIR_NONCE_TAIL,
+
+	__OVPN_A_KEYDIR_MAX,
+	OVPN_A_KEYDIR_MAX = (__OVPN_A_KEYDIR_MAX - 1)
+};
+
+enum {
+	OVPN_A_IFINDEX = 1,
+	OVPN_A_PEER,
+	OVPN_A_KEYCONF,
+
+	__OVPN_A_MAX,
+	OVPN_A_MAX = (__OVPN_A_MAX - 1)
+};
+
+enum {
+	OVPN_CMD_PEER_NEW = 1,
+	OVPN_CMD_PEER_SET,
+	OVPN_CMD_PEER_GET,
+	OVPN_CMD_PEER_DEL,
+	OVPN_CMD_PEER_DEL_NTF,
+	OVPN_CMD_KEY_NEW,
+	OVPN_CMD_KEY_GET,
+	OVPN_CMD_KEY_SWAP,
+	OVPN_CMD_KEY_SWAP_NTF,
+	OVPN_CMD_KEY_DEL,
+
+	__OVPN_CMD_MAX,
+	OVPN_CMD_MAX = (__OVPN_CMD_MAX - 1)
+};
+
+#define OVPN_MCGRP_PEERS	"peers"
+
+#endif /* _UAPI_LINUX_OVPN_H */