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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-04-19 16:17:34 (GMT) |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-04-19 16:17:34 (GMT) |
commit | cf816ecb533ab96b883dfdc0db174598b5b5c4d2 (patch) | |
tree | 1b7705db288ae2917105e624b01fdf81e0882bf1 /net/core/skbuff.c | |
parent | adf6d34e460387ee3e8f1e1875d52bff51212c7d (diff) | |
parent | 15f7d677ccff6f0f5de8a1ee43a792567e9f9de9 (diff) | |
download | linux-fsl-qoriq-cf816ecb533ab96b883dfdc0db174598b5b5c4d2.tar.xz |
Merge branch 'merge-fixes' into devel
Diffstat (limited to 'net/core/skbuff.c')
-rw-r--r-- | net/core/skbuff.c | 100 |
1 files changed, 97 insertions, 3 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0d0fd28..4fe605f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -263,6 +263,28 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, return skb; } +/** + * dev_alloc_skb - allocate an skbuff for receiving + * @length: length to allocate + * + * Allocate a new &sk_buff and assign it a usage count of one. The + * buffer has unspecified headroom built in. Users should allocate + * the headroom they think they need without accounting for the + * built in space. The built in space is used for optimisations. + * + * %NULL is returned if there is no free memory. Although this function + * allocates memory it can be called from an interrupt. + */ +struct sk_buff *dev_alloc_skb(unsigned int length) +{ + /* + * There is more code here than it seems: + * __dev_alloc_skb is an inline + */ + return __dev_alloc_skb(length, GFP_ATOMIC); +} +EXPORT_SYMBOL(dev_alloc_skb); + static void skb_drop_list(struct sk_buff **listp) { struct sk_buff *list = *listp; @@ -857,6 +879,78 @@ free_skb: return err; } +/** + * 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. + */ +unsigned char *skb_put(struct sk_buff *skb, unsigned int len) +{ + unsigned char *tmp = skb_tail_pointer(skb); + SKB_LINEAR_ASSERT(skb); + skb->tail += len; + skb->len += len; + if (unlikely(skb->tail > skb->end)) + skb_over_panic(skb, len, __builtin_return_address(0)); + return tmp; +} +EXPORT_SYMBOL(skb_put); + +/** + * 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. + */ +unsigned char *skb_push(struct sk_buff *skb, unsigned int len) +{ + skb->data -= len; + skb->len += len; + if (unlikely(skb->data<skb->head)) + skb_under_panic(skb, len, __builtin_return_address(0)); + return skb->data; +} +EXPORT_SYMBOL(skb_push); + +/** + * 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. + */ +unsigned char *skb_pull(struct sk_buff *skb, unsigned int len) +{ + return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); +} +EXPORT_SYMBOL(skb_pull); + +/** + * skb_trim - remove end from a buffer + * @skb: buffer to alter + * @len: new length + * + * Cut the length of a buffer down by removing data from the tail. If + * the buffer is already under the length specified it is not modified. + * The skb must be linear. + */ +void skb_trim(struct sk_buff *skb, unsigned int len) +{ + if (skb->len > len) + __skb_trim(skb, len); +} +EXPORT_SYMBOL(skb_trim); + /* Trims skb to length len. It can change skb pointers. */ @@ -1766,7 +1860,7 @@ void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head unsigned long flags; spin_lock_irqsave(&list->lock, flags); - __skb_append(old, newsk, list); + __skb_queue_after(list, old, newsk); spin_unlock_irqrestore(&list->lock, flags); } @@ -2131,8 +2225,8 @@ EXPORT_SYMBOL_GPL(skb_pull_rcsum); * @features: features for the output path (see dev->features) * * This function performs segmentation on the given skb. It returns - * the segment at the given position. It returns NULL if there are - * no more segments to generate, or when an error is encountered. + * a pointer to the first in a list of new skbs for the segments. + * In case of error it returns ERR_PTR(err). */ struct sk_buff *skb_segment(struct sk_buff *skb, int features) { |