sock.h

#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
			    SOCK_SKB_CB_OFFSET))

#define sock_skb_cb_check_size(size) \
	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)

static inline void
sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
{
	SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops);
}

void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
			   struct sk_buff *skb);
void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
			     struct sk_buff *skb);

static inline void
sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
{
	ktime_t kt = skb->tstamp;
	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);

	/*
	 * generate control messages if
	 * - receive time stamping in software requested
	 * - software time stamp available and wanted
	 * - hardware time stamps available and wanted
	 */
	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
	    (kt.tv64 && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
	    (hwtstamps->hwtstamp.tv64 &&
	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
		__sock_recv_timestamp(msg, sk, skb);
	else
		sk->sk_stamp = kt;

	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
		__sock_recv_wifi_status(msg, sk, skb);
}

void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
			      struct sk_buff *skb);

static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
					  struct sk_buff *skb)
{
#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
			   (1UL << SOCK_RCVTSTAMP))
#define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
			   SOF_TIMESTAMPING_RAW_HARDWARE)

	if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
		__sock_recv_ts_and_drops(msg, sk, skb);
	else
		sk->sk_stamp = skb->tstamp;
}

void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags);

/**
 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
 * @sk:		socket sending this packet
 * @tx_flags:	completed with instructions for time stamping
 *
 * Note : callers should take care of initial *tx_flags value (usually 0)
 */
static inline void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags)
{
	if (unlikely(sk->sk_tsflags))
		__sock_tx_timestamp(sk, tx_flags);
	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
		*tx_flags |= SKBTX_WIFI_STATUS;
}

/**
 * sk_eat_skb - Release a skb if it is no longer needed
 * @sk: socket to eat this skb from
 * @skb: socket buffer to eat
 *
 * This routine must be called with interrupts disabled or with the socket
 * locked so that the sk_buff queue operation is ok.
*/
static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
{
	__skb_unlink(skb, &sk->sk_receive_queue);
	__kfree_skb(skb);
}

static inline
struct net *sock_net(const struct sock *sk)
{
	return read_pnet(&sk->sk_net);
}

static inline
void sock_net_set(struct sock *sk, struct net *net)
{
	write_pnet(&sk->sk_net, net);
}

static inline struct sock *skb_steal_sock(struct sk_buff *skb)
{
	if (skb->sk) {
		struct sock *sk = skb->sk;

		skb->destructor = NULL;
		skb->sk = NULL;
		return sk;
	}
	return NULL;
}

/* This helper checks if a socket is a full socket,
 * ie _not_ a timewait or request socket.
 */
static inline bool sk_fullsock(const struct sock *sk)
{
	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
}

/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
 */
static inline bool sk_listener(const struct sock *sk)
{
	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
}

/**
 * sk_state_load - read sk->sk_state for lockless contexts
 * @sk: socket pointer
 *
 * Paired with sk_state_store(). Used in places we do not hold socket lock :
 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
 */
static inline int sk_state_load(const struct sock *sk)
{
	return smp_load_acquire(&sk->sk_state);
}

/**
 * sk_state_store - update sk->sk_state
 * @sk: socket pointer
 * @newstate: new state
 *
 * Paired with sk_state_load(). Should be used in contexts where
 * state change might impact lockless readers.
 */
static inline void sk_state_store(struct sock *sk, int newstate)
{
	smp_store_release(&sk->sk_state, newstate);
}

void sock_enable_timestamp(struct sock *sk, int flag);
int sock_get_timestamp(struct sock *, struct timeval __user *);
int sock_get_timestampns(struct sock *, struct timespec __user *);
int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
		       int type);

bool sk_ns_capable(const struct sock *sk,
		   struct user_namespace *user_ns, int cap);
bool sk_capable(const struct sock *sk, int cap);
bool sk_net_capable(const struct sock *sk, int cap);

extern __u32 sysctl_wmem_max;
extern __u32 sysctl_rmem_max;

extern int sysctl_tstamp_allow_data;
extern int sysctl_optmem_max;

extern __u32 sysctl_wmem_default;
extern __u32 sysctl_rmem_default;

#endif	/* _SOCK_H */