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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __NET_PSP_HELPERS_H
#define __NET_PSP_HELPERS_H
#include <linux/skbuff.h>
#include <linux/rcupdate.h>
#include <linux/udp.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <net/psp/types.h>
struct inet_timewait_sock;
/* Driver-facing API */
struct psp_dev *
psp_dev_create(struct net_device *netdev, struct psp_dev_ops *psd_ops,
struct psp_dev_caps *psd_caps, void *priv_ptr);
void psp_dev_unregister(struct psp_dev *psd);
bool psp_dev_encapsulate(struct net *net, struct sk_buff *skb, __be32 spi,
u8 ver, __be16 sport);
int psp_dev_rcv(struct sk_buff *skb, u16 dev_id, u8 generation, bool strip_icv);
/* Kernel-facing API */
void psp_assoc_put(struct psp_assoc *pas);
static inline void *psp_assoc_drv_data(struct psp_assoc *pas)
{
return pas->drv_data;
}
#if IS_ENABLED(CONFIG_INET_PSP)
unsigned int psp_key_size(u32 version);
void psp_sk_assoc_free(struct sock *sk);
void psp_twsk_init(struct inet_timewait_sock *tw, const struct sock *sk);
void psp_twsk_assoc_free(struct inet_timewait_sock *tw);
void psp_reply_set_decrypted(struct sk_buff *skb);
static inline struct psp_assoc *psp_sk_assoc(const struct sock *sk)
{
return rcu_dereference_check(sk->psp_assoc, lockdep_sock_is_held(sk));
}
static inline void
psp_enqueue_set_decrypted(struct sock *sk, struct sk_buff *skb)
{
struct psp_assoc *pas;
pas = psp_sk_assoc(sk);
if (pas && pas->tx.spi)
skb->decrypted = 1;
}
static inline unsigned long
__psp_skb_coalesce_diff(const struct sk_buff *one, const struct sk_buff *two,
unsigned long diffs)
{
struct psp_skb_ext *a, *b;
a = skb_ext_find(one, SKB_EXT_PSP);
b = skb_ext_find(two, SKB_EXT_PSP);
diffs |= (!!a) ^ (!!b);
if (!diffs && unlikely(a))
diffs |= memcmp(a, b, sizeof(*a));
return diffs;
}
static inline bool
psp_is_allowed_nondata(struct sk_buff *skb, struct psp_assoc *pas)
{
bool fin = !!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN);
u32 end_seq = TCP_SKB_CB(skb)->end_seq;
u32 seq = TCP_SKB_CB(skb)->seq;
bool pure_fin;
pure_fin = fin && end_seq - seq == 1;
return seq == end_seq || (pure_fin && seq == pas->upgrade_seq);
}
static inline bool
psp_pse_matches_pas(struct psp_skb_ext *pse, struct psp_assoc *pas)
{
return pse && pas->rx.spi == pse->spi &&
pas->generation == pse->generation &&
pas->version == pse->version &&
pas->dev_id == pse->dev_id;
}
static inline enum skb_drop_reason
__psp_sk_rx_policy_check(struct sk_buff *skb, struct psp_assoc *pas)
{
struct psp_skb_ext *pse = skb_ext_find(skb, SKB_EXT_PSP);
if (!pas)
return pse ? SKB_DROP_REASON_PSP_INPUT : 0;
if (likely(psp_pse_matches_pas(pse, pas))) {
if (unlikely(!pas->peer_tx))
pas->peer_tx = 1;
return 0;
}
if (!pse) {
if (!pas->tx.spi ||
(!pas->peer_tx && psp_is_allowed_nondata(skb, pas)))
return 0;
}
return SKB_DROP_REASON_PSP_INPUT;
}
static inline enum skb_drop_reason
psp_sk_rx_policy_check(struct sock *sk, struct sk_buff *skb)
{
return __psp_sk_rx_policy_check(skb, psp_sk_assoc(sk));
}
static inline enum skb_drop_reason
psp_twsk_rx_policy_check(struct inet_timewait_sock *tw, struct sk_buff *skb)
{
return __psp_sk_rx_policy_check(skb, rcu_dereference(tw->psp_assoc));
}
static inline struct psp_assoc *psp_sk_get_assoc_rcu(const struct sock *sk)
{
struct psp_assoc *pas;
int state;
state = READ_ONCE(sk->sk_state);
if (!sk_is_inet(sk) || state == TCP_NEW_SYN_RECV)
return NULL;
pas = state == TCP_TIME_WAIT ?
rcu_dereference(inet_twsk(sk)->psp_assoc) :
rcu_dereference(sk->psp_assoc);
return pas;
}
static inline struct psp_assoc *psp_skb_get_assoc_rcu(struct sk_buff *skb)
{
if (!skb->decrypted || !skb->sk)
return NULL;
return psp_sk_get_assoc_rcu(skb->sk);
}
static inline unsigned int psp_sk_overhead(const struct sock *sk)
{
int psp_encap = sizeof(struct udphdr) + PSP_HDR_SIZE + PSP_TRL_SIZE;
bool has_psp = rcu_access_pointer(sk->psp_assoc);
return has_psp ? psp_encap : 0;
}
#else
static inline void psp_sk_assoc_free(struct sock *sk) { }
static inline void
psp_twsk_init(struct inet_timewait_sock *tw, const struct sock *sk) { }
static inline void psp_twsk_assoc_free(struct inet_timewait_sock *tw) { }
static inline void
psp_reply_set_decrypted(struct sk_buff *skb) { }
static inline struct psp_assoc *psp_sk_assoc(const struct sock *sk)
{
return NULL;
}
static inline void
psp_enqueue_set_decrypted(struct sock *sk, struct sk_buff *skb) { }
static inline unsigned long
__psp_skb_coalesce_diff(const struct sk_buff *one, const struct sk_buff *two,
unsigned long diffs)
{
return diffs;
}
static inline enum skb_drop_reason
psp_sk_rx_policy_check(struct sock *sk, struct sk_buff *skb)
{
return 0;
}
static inline enum skb_drop_reason
psp_twsk_rx_policy_check(struct inet_timewait_sock *tw, struct sk_buff *skb)
{
return 0;
}
static inline struct psp_assoc *psp_skb_get_assoc_rcu(struct sk_buff *skb)
{
return NULL;
}
static inline unsigned int psp_sk_overhead(const struct sock *sk)
{
return 0;
}
#endif
static inline unsigned long
psp_skb_coalesce_diff(const struct sk_buff *one, const struct sk_buff *two)
{
return __psp_skb_coalesce_diff(one, two, 0);
}
#endif /* __NET_PSP_HELPERS_H */
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