tcpcore.h

winNT技术操作系统,国外开放的原代码和LIUX一样

	list->prev = (struct sk_buff *)list;
	list->next = (struct sk_buff *)list;
	list->qlen = 0;
}

/*
 *	Insert an sk_buff at the start of a list.
 *
 *	The "__skb_xxxx()" functions are the non-atomic ones that
 *	can only be called with interrupts disabled.
 */

/**
 *	__skb_queue_head - queue a buffer at the list head
 *	@list: list to use
 *	@newsk: buffer to queue
 *
 *	Queue a buffer at the start of a list. This function takes no locks
 *	and you must therefore hold required locks before calling it.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */

static __inline void __skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk)
{
	struct sk_buff *prev, *next;

	newsk->list = list;
	list->qlen++;
	prev = (struct sk_buff *)list;
	next = prev->next;
	newsk->next = next;
	newsk->prev = prev;
	next->prev = newsk;
	prev->next = newsk;
}


/**
 *	skb_queue_head - queue a buffer at the list head
 *	@list: list to use
 *	@newsk: buffer to queue
 *
 *	Queue a buffer at the start of the list. This function takes the
 *	list lock and can be used safely with other locking &sk_buff functions
 *	safely.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */

static __inline void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk)
{
	unsigned long flags;

	spin_lock_irqsave(&list->lock, flags);
	__skb_queue_head(list, newsk);
	spin_unlock_irqrestore(&list->lock, flags);
}

/**
 *	__skb_queue_tail - queue a buffer at the list tail
 *	@list: list to use
 *	@newsk: buffer to queue
 *
 *	Queue a buffer at the end of a list. This function takes no locks
 *	and you must therefore hold required locks before calling it.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */


static __inline void __skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk)
{
	struct sk_buff *prev, *next;

	newsk->list = list;
	list->qlen++;
	next = (struct sk_buff *)list;
	prev = next->prev;
	newsk->next = next;
	newsk->prev = prev;
	next->prev = newsk;
	prev->next = newsk;
}

/**
 *	skb_queue_tail - queue a buffer at the list tail
 *	@list: list to use
 *	@newsk: buffer to queue
 *
 *	Queue a buffer at the tail of the list. This function takes the
 *	list lock and can be used safely with other locking &sk_buff functions
 *	safely.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */

static __inline void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk)
{
	unsigned long flags;

	spin_lock_irqsave(&list->lock, flags);
	__skb_queue_tail(list, newsk);
	spin_unlock_irqrestore(&list->lock, flags);
}

/**
 *	__skb_dequeue - remove from the head of the queue
 *	@list: list to dequeue from
 *
 *	Remove the head of the list. This function does not take any locks
 *	so must be used with appropriate locks held only. The head item is
 *	returned or %NULL if the list is empty.
 */

static __inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
{
	struct sk_buff *next, *prev, *result;

	prev = (struct sk_buff *) list;
	next = prev->next;
	result = NULL;
	if (next != prev) {
		result = next;
		next = next->next;
		list->qlen--;
		next->prev = prev;
		prev->next = next;
		result->next = NULL;
		result->prev = NULL;
		result->list = NULL;
	}
	return result;
}

/**
 *	skb_dequeue - remove from the head of the queue
 *	@list: list to dequeue from
 *
 *	Remove the head of the list. The list lock is taken so the function
 *	may be used safely with other locking list functions. The head item is
 *	returned or %NULL if the list is empty.
 */

static __inline struct sk_buff *skb_dequeue(struct sk_buff_head *list)
{
	unsigned long flags;
	struct sk_buff *result;

	spin_lock_irqsave(&list->lock, flags);
	result = __skb_dequeue(list);
	spin_unlock_irqrestore(&list->lock, flags);
	return result;
}

/*
 *	Insert a packet on a list.
 */

static __inline void __skb_insert(struct sk_buff *newsk,
	struct sk_buff * prev, struct sk_buff *next,
	struct sk_buff_head * list)
{
	newsk->next = next;
	newsk->prev = prev;
	next->prev = newsk;
	prev->next = newsk;
	newsk->list = list;
	list->qlen++;
}

/**
 *	skb_insert	-	insert a buffer
 *	@old: buffer to insert before
 *	@newsk: buffer to insert
 *
 *	Place a packet before a given packet in a list. The list locks are taken
 *	and this function is atomic with respect to other list locked calls
 *	A buffer cannot be placed on two lists at the same time.
 */

static __inline void skb_insert(struct sk_buff *old, struct sk_buff *newsk)
{
	unsigned long flags;

	spin_lock_irqsave(&old->list->lock, flags);
	__skb_insert(newsk, old->prev, old, old->list);
	spin_unlock_irqrestore(&old->list->lock, flags);
}

/*
 *	Place a packet after a given packet in a list.
 */

static __inline void __skb_append(struct sk_buff *old, struct sk_buff *newsk)
{
	__skb_insert(newsk, old, old->next, old->list);
}

/**
 *	skb_append	-	append a buffer
 *	@old: buffer to insert after
 *	@newsk: buffer to insert
 *
 *	Place a packet after a given packet in a list. The list locks are taken
 *	and this function is atomic with respect to other list locked calls.
 *	A buffer cannot be placed on two lists at the same time.
 */


static __inline void skb_append(struct sk_buff *old, struct sk_buff *newsk)
{
	unsigned long flags;

	spin_lock_irqsave(&old->list->lock, flags);
	__skb_append(old, newsk);
	spin_unlock_irqrestore(&old->list->lock, flags);
}

/*
 * remove sk_buff from list. _Must_ be called atomically, and with
 * the list known..
 */

static __inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
{
	struct sk_buff * next, * prev;

	list->qlen--;
	next = skb->next;
	prev = skb->prev;
	skb->next = NULL;
	skb->prev = NULL;
	skb->list = NULL;
	next->prev = prev;
	prev->next = next;
}

/**
 *	skb_unlink	-	remove a buffer from a list
 *	@skb: buffer to remove
 *
 *	Place a packet after a given packet in a list. The list locks are taken
 *	and this function is atomic with respect to other list locked calls
 *
 *	Works even without knowing the list it is sitting on, which can be
 *	handy at times. It also means that THE LIST MUST EXIST when you
 *	unlink. Thus a list must have its contents unlinked before it is
 *	destroyed.
 */

static __inline void skb_unlink(struct sk_buff *skb)
{
	struct sk_buff_head *list = skb->list;

	if(list) {
		unsigned long flags;

		spin_lock_irqsave(&list->lock, flags);
		if(skb->list == list)
			__skb_unlink(skb, skb->list);
		spin_unlock_irqrestore(&list->lock, flags);
	}
}

/* XXX: more streamlined implementation */

/**
 *	__skb_dequeue_tail - remove from the tail of the queue
 *	@list: list to dequeue from
 *
 *	Remove the tail of the list. This function does not take any locks
 *	so must be used with appropriate locks held only. The tail item is
 *	returned or %NULL if the list is empty.
 */

static __inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
{
	struct sk_buff *skb = skb_peek_tail(list);
	if (skb)
		__skb_unlink(skb, list);
	return skb;
}

/**
 *	skb_dequeue - remove from the head of the queue
 *	@list: list to dequeue from
 *
 *	Remove the head of the list. The list lock is taken so the function
 *	may be used safely with other locking list functions. The tail item is
 *	returned or %NULL if the list is empty.
 */

static __inline struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list)
{
	unsigned long flags;
	struct sk_buff *result;

	spin_lock_irqsave(&list->lock, flags);
	result = __skb_dequeue_tail(list);
	spin_unlock_irqrestore(&list->lock, flags);
	return result;
}

static __inline int skb_is_nonlinear(const struct sk_buff *skb)
{
	return skb->data_len;
}

static __inline int skb_headlen(const struct sk_buff *skb)
{
	return skb->len - skb->data_len;
}

#define SKB_PAGE_ASSERT(skb) do { if (skb_shinfo(skb)->nr_frags) out_of_line_bug(); } while (0)
#define SKB_FRAG_ASSERT(skb) do { if (skb_shinfo(skb)->frag_list) out_of_line_bug(); } while (0)
#define SKB_LINEAR_ASSERT(skb) do { if (skb_is_nonlinear(skb)) out_of_line_bug(); } while (0)

/*
 *	Add data to an sk_buff
 */

static __inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
{
	unsigned char *tmp=skb->tail;
	SKB_LINEAR_ASSERT(skb);
	skb->tail+=len;
	skb->len+=len;
	return tmp;
}

/**
 *	skb_put - add data to a buffer
 *	@skb: buffer to use
 *	@len: amount of data to add
 *
 *	This function extends the used data area of the buffer. If this would
 *	exceed the total buffer size the kernel will panic. A pointer to the
 *	first byte of the extra data is returned.
 */

static __inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
{
#if 0
	unsigned char *tmp=skb->tail;
	SKB_LINEAR_ASSERT(skb);
	skb->tail+=len;
	skb->len+=len;
	if(skb->tail>skb->end) {
		skb_over_panic(skb, len, current_text_addr());
	}
	return tmp;
#else
return NULL;
#endif
}

static __inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
{
	skb->data-=len;
	skb->len+=len;
	return skb->data;
}

/**
 *	skb_push - add data to the start of a buffer
 *	@skb: buffer to use
 *	@len: amount of data to add
 *
 *	This function extends the used data area of the buffer at the buffer
 *	start. If this would exceed the total buffer headroom the kernel will
 *	panic. A pointer to the first byte of the extra data is returned.
 */

static __inline unsigned char *skb_push(struct sk_buff *skb, unsigned int len)
{
#if 0
	skb->data-=len;
	skb->len+=len;
	if(skb->data<skb->head) {
		skb_under_panic(skb, len, current_text_addr());
	}
	return skb->data;
#else
  return NULL;
#endif
}

static __inline char *__skb_pull(struct sk_buff *skb, unsigned int len)
{
	skb->len-=len;
	if (skb->len < skb->data_len)
		out_of_line_bug();
	return 	skb->data+=len;
}

/**
 *	skb_pull - remove data from the start of a buffer
 *	@skb: buffer to use
 *	@len: amount of data to remove
 *
 *	This function removes data from the start of a buffer, returning
 *	the memory to the headroom. A pointer to the next data in the buffer
 *	is returned. Once the data has been pulled future pushes will overwrite
 *	the old data.
 */

static __inline unsigned char * skb_pull(struct sk_buff *skb, unsigned int len)
{
	if (len > skb->len)
		return NULL;
	return __skb_pull(skb,len);
}

extern unsigned char * __pskb_pull_tail(struct sk_buff *skb, int delta);

static __inline char *__pskb_pull(struct sk_buff *skb, unsigned int len)
{
	if (len > skb_headlen(skb) &&
	    __pskb_pull_tail(skb, len-skb_headlen(skb)) == NULL)
		return NULL;
	skb->len -= len;
	return 	skb->data += len;
}

static __inline unsigned char * pskb_pull(struct sk_buff *skb, unsigned int len)
{
	if (len > skb->len)
		return NULL;
	return __pskb_pull(skb,len);
}

static __inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
{
	if (len <= skb_headlen(skb))
		return 1;
	if (len > skb->len)
		return 0;
	return (__pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL);
}

/**
 *	skb_headroom - bytes at buffer head
 *	@skb: buffer to check
 *
 *	Return the number of bytes of free space at the head of an &sk_buff.
 */

static __inline int skb_headroom(const struct sk_buff *skb)
{
	return skb->data-skb->head;
}