/* SPDX-License-Identifier: GPL-2.0-only */ /* OpenVPN data channel offload * * Copyright (C) 2020-2025 OpenVPN, Inc. * * Author: Antonio Quartulli <antonio@openvpn.net> * James Yonan <james@openvpn.net> */ #ifndef _NET_OVPN_SKB_H_ #define _NET_OVPN_SKB_H_ #include <linux/in.h> #include <linux/in6.h> #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/skbuff.h> #include <linux/socket.h> #include <linux/types.h> /** * struct ovpn_cb - ovpn skb control block * @peer: the peer this skb was received from/sent to * @ks: the crypto key slot used to encrypt/decrypt this skb * @crypto_tmp: pointer to temporary memory used for crypto operations * containing the IV, the scatter gather list and the aead request * @payload_offset: offset in the skb where the payload starts * @nosignal: whether this skb should be sent with the MSG_NOSIGNAL flag (TCP) */ struct ovpn_cb { struct ovpn_peer *peer; struct ovpn_crypto_key_slot *ks; void *crypto_tmp; unsigned int payload_offset; bool nosignal; }; static inline struct ovpn_cb *ovpn_skb_cb(struct sk_buff *skb) { BUILD_BUG_ON(sizeof(struct ovpn_cb) > sizeof(skb->cb)); return (struct ovpn_cb *)skb->cb; } /* Return IP protocol version from skb header. * Return 0 if protocol is not IPv4/IPv6 or cannot be read. */ static inline __be16 ovpn_ip_check_protocol(struct sk_buff *skb) { __be16 proto = 0; /* skb could be non-linear, * make sure IP header is in non-fragmented part */ if (!pskb_network_may_pull(skb, sizeof(struct iphdr))) return 0; if (ip_hdr(skb)->version == 4) { proto = htons(ETH_P_IP); } else if (ip_hdr(skb)->version == 6) { if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr))) return 0; proto = htons(ETH_P_IPV6); } return proto; } #endif /* _NET_OVPN_SKB_H_ */