sock.h

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

	int			ip_ttl;			/* TTL setting */
	int			ip_tos;			/* TOS */
	struct tcphdr		dummy_th;
	struct timer_list	keepalive_timer;	/* TCP keepalive hack */
	struct timer_list	retransmit_timer;	/* TCP retransmit timer */
	struct timer_list	delack_timer;		/* TCP delayed ack timer */
	int			ip_xmit_timeout;	/* Why the timeout is running */
	struct rtable		*ip_route_cache;	/* Cached output route */
	unsigned char		ip_hdrincl;		/* Include headers ? */
#ifdef CONFIG_IP_MULTICAST  
	int			ip_mc_ttl;		/* Multicasting TTL */
	int			ip_mc_loop;		/* Loopback */
	char			ip_mc_name[MAX_ADDR_LEN];/* Multicast device name */
	struct ip_mc_socklist	*ip_mc_list;		/* Group array */
#endif  

/*
 *	This part is used for the timeout functions (timer.c). 
 */
 
	int			timeout;	/* What are we waiting for? */
	struct timer_list	timer;		/* This is the TIME_WAIT/receive timer
					 * when we are doing IP
					 */
	struct timeval		stamp;

 /*
  *	Identd 
  */
  
	struct socket		*socket;
  
  /*
   *	Callbacks 
   */
   
	void			(*state_change)(struct sock *sk);
	void			(*data_ready)(struct sock *sk,int bytes);
	void			(*write_space)(struct sock *sk);
	void			(*error_report)(struct sock *sk);

  /*
   *	Moved solely for 2.0 to keep binary module compatibility stuff straight.
   */
   
	unsigned short		max_ack_backlog;
	struct sock		*listening;
};

/*
 *	IP protocol blocks we attach to sockets.
 */
 
struct proto 
{
	/* These must be first. */
	struct sock		*sklist_next;
	struct sock		*sklist_prev;

	void			(*close)(struct sock *sk, unsigned long timeout);
	int			(*build_header)(struct sk_buff *skb,
					__u32 saddr,
					__u32 daddr,
					struct device **dev, int type,
					struct options *opt, int len,
					int tos, int ttl, struct rtable ** rp);
	int			(*connect)(struct sock *sk,
				        struct sockaddr_in *usin, int addr_len);
	struct sock *		(*accept) (struct sock *sk, int flags);
	void			(*queue_xmit)(struct sock *sk,
				        struct device *dev, struct sk_buff *skb,
				        int free);
	void			(*retransmit)(struct sock *sk, int all);
	void			(*write_wakeup)(struct sock *sk);
	void			(*read_wakeup)(struct sock *sk);
	int			(*rcv)(struct sk_buff *buff, struct device *dev,
				        struct options *opt, __u32 daddr,
				        unsigned short len, __u32 saddr,
				        int redo, struct inet_protocol *protocol);
	int			(*select)(struct sock *sk, int which,
					select_table *wait);
	int			(*ioctl)(struct sock *sk, int cmd,
					unsigned long arg);
	int			(*init)(struct sock *sk);
	void			(*shutdown)(struct sock *sk, int how);
	int			(*setsockopt)(struct sock *sk, int level, int optname,
					char *optval, int optlen);
	int			(*getsockopt)(struct sock *sk, int level, int optname,
					char *optval, int *option);  	 
	int			(*sendmsg)(struct sock *sk, struct msghdr *msg, int len,
					int noblock, int flags);
	int			(*recvmsg)(struct sock *sk, struct msghdr *msg, int len,
					int noblock, int flags, int *addr_len);
	int			(*bind)(struct sock *sk, struct sockaddr *uaddr, int addr_len);

	/* Keeping track of sk's, looking them up, and port selection methods. */
	void			(*hash)(struct sock *sk);
	void			(*unhash)(struct sock *sk);
	void			(*rehash)(struct sock *sk);
	unsigned short		(*good_socknum)(void);
	int			(*verify_bind)(struct sock *sk, unsigned short snum);

	unsigned short		max_header;
	unsigned long		retransmits;
	char			name[32];
	int			inuse, highestinuse;
};

#define TIME_WRITE	1
#define TIME_CLOSE	2
#define TIME_KEEPOPEN	3
#define TIME_DESTROY	4
#define TIME_DONE	5	/* Used to absorb those last few packets */
#define TIME_PROBE0	6

/*
 *	About 10 seconds 
 */

#define SOCK_DESTROY_TIME (10*HZ)

/*
 *	Sockets 0-1023 can't be bound to unless you are superuser 
 */
 
#define PROT_SOCK	1024

#define SHUTDOWN_MASK	3
#define RCV_SHUTDOWN	1
#define SEND_SHUTDOWN	2

/* Per-protocol hash table implementations use this to make sure
 * nothing changes.
 */
#define SOCKHASH_LOCK()		start_bh_atomic()
#define SOCKHASH_UNLOCK()	end_bh_atomic()

/* Some things in the kernel just want to get at a protocols
 * entire socket list commensurate, thus...
 */
static __inline__ void add_to_prot_sklist(struct sock *sk)
{
	SOCKHASH_LOCK();
	if(!sk->sklist_next) {
		struct proto *p = sk->prot;

		sk->sklist_prev = (struct sock *) p;
		sk->sklist_next = p->sklist_next;
		p->sklist_next->sklist_prev = sk;
		p->sklist_next = sk;

		/* Charge the protocol. */
		sk->prot->inuse += 1;
		if(sk->prot->highestinuse < sk->prot->inuse)
			sk->prot->highestinuse = sk->prot->inuse;
	}
	SOCKHASH_UNLOCK();
}

static __inline__ void del_from_prot_sklist(struct sock *sk)
{
	SOCKHASH_LOCK();
	if(sk->sklist_next) {
		sk->sklist_next->sklist_prev = sk->sklist_prev;
		sk->sklist_prev->sklist_next = sk->sklist_next;
		sk->sklist_next = NULL;
		sk->prot->inuse--;
	}
	SOCKHASH_UNLOCK();
}

/*
 * Used by processes to "lock" a socket state, so that
 * interrupts and bottom half handlers won't change it
 * from under us. It essentially blocks any incoming
 * packets, so that we won't get any new data or any
 * packets that change the state of the socket.
 *
 * Note the 'barrier()' calls: gcc may not move a lock
 * "downwards" or a unlock "upwards" when optimizing.
 */
extern void __release_sock(struct sock *sk);

static inline void lock_sock(struct sock *sk)
{
#if 0
/* debugging code: the test isn't even 100% correct, but it can catch bugs */
/* Note that a double lock is ok in theory - it's just _usually_ a bug */
	if (sk->users) {
		__label__ here;
		printk("double lock on socket at %p\n", &&here);
here:
	}
#endif
	sk->users++;
	barrier();
}

static inline void release_sock(struct sock *sk)
{
	barrier();
#if 0
/* debugging code: remove me when ok */
	if (sk->users == 0) {
		__label__ here;
		sk->users = 1;
		printk("trying to unlock unlocked socket at %p\n", &&here);
here:
	}
#endif
	if ((sk->users = sk->users-1) == 0)
		__release_sock(sk);
}


extern struct sock *		sk_alloc(int priority);
extern void			sk_free(struct sock *sk);
extern void			destroy_sock(struct sock *sk);

extern struct sk_buff		*sock_wmalloc(struct sock *sk,
					      unsigned long size, int force,
					      int priority);
extern struct sk_buff		*sock_rmalloc(struct sock *sk,
					      unsigned long size, int force,
					      int priority);
extern void			sock_wfree(struct sock *sk,
					   struct sk_buff *skb);
extern void			sock_rfree(struct sock *sk,
					   struct sk_buff *skb);
extern unsigned long		sock_rspace(struct sock *sk);
extern unsigned long		sock_wspace(struct sock *sk);

extern int			sock_setsockopt(struct sock *sk, int level,
						int op, char *optval,
						int optlen);

extern int			sock_getsockopt(struct sock *sk, int level,
						int op, char *optval, 
						int *optlen);
extern struct sk_buff 		*sock_alloc_send_skb(struct sock *skb,
						     unsigned long size,
						     unsigned long fallback,
						     int noblock,
						     int *errcode);

/*
 * 	Queue a received datagram if it will fit. Stream and sequenced
 *	protocols can't normally use this as they need to fit buffers in
 *	and play with them.
 *
 * 	Inlined as it's very short and called for pretty much every
 *	packet ever received.
 */

extern __inline__ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	if (sk->rmem_alloc + skb->truesize >= sk->rcvbuf)
		return -ENOMEM;
	atomic_add(skb->truesize, &sk->rmem_alloc);
	skb->sk=sk;
	skb_queue_tail(&sk->receive_queue,skb);
	if (!sk->dead)
		sk->data_ready(sk,skb->len);
	return 0;
}

extern __inline__ int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	if (sk->rmem_alloc + skb->truesize >= sk->rcvbuf)
		return -ENOMEM;
	atomic_add(skb->truesize, &sk->rmem_alloc);
	skb->sk=sk;
	__skb_queue_tail(&sk->receive_queue,skb);
	if (!sk->dead)
		sk->data_ready(sk,skb->len);
	return 0;
}

/*
 *	Recover an error report and clear atomically
 */
 
extern __inline__ int sock_error(struct sock *sk)
{
	int err=xchg(&sk->err,0);
	return -err;
}

/* 
 *	Declarations from timer.c 
 */
 
extern struct sock *timer_base;

extern void delete_timer (struct sock *);
extern void reset_timer (struct sock *, int, unsigned long);
extern void net_timer (unsigned long);


/* 
 *	Enable debug/info messages 
 */

#define NETDEBUG(x)	do { } while (0)

#endif	/* _SOCK_H */