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net: core: Specify skb_pad()/skb_put_padto() SKB freeing

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Rename skb_pad() into __skb_pad() and make it take a third argument:
free_on_error which controls whether kfree_skb() should be called or
not, skb_pad() directly makes use of it and passes true to preserve its
existing behavior. Do exactly the same thing with __skb_put_padto() and
skb_put_padto().

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Woojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Fainelli 2017-08-22 15:12:14 -07:00 committed by David S. Miller
parent 013dae5dbc
commit cd0a137acb
2 changed files with 51 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
include/linux/skbuff.h
View File

@ -973,7 +973,23 @@ int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg
int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
int offset, int len);
int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
int skb_pad(struct sk_buff *skb, int pad);
int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
/**
* skb_pad - zero pad the tail of an skb
* @skb: buffer to pad
* @pad: space to pad
*
* Ensure that a buffer is followed by a padding area that is zero
* filled. Used by network drivers which may DMA or transfer data
* beyond the buffer end onto the wire.
*
* May return error in out of memory cases. The skb is freed on error.
*/
static inline int skb_pad(struct sk_buff *skb, int pad)
{
return __skb_pad(skb, pad, true);
}
#define dev_kfree_skb(a) consume_skb(a)
int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
@ -2821,6 +2837,31 @@ static inline int skb_padto(struct sk_buff *skb, unsigned int len)
return skb_pad(skb, len - size);
}
/**
* skb_put_padto - increase size and pad an skbuff up to a minimal size
* @skb: buffer to pad
* @len: minimal length
* @free_on_error: free buffer on error
*
* Pads up a buffer to ensure the trailing bytes exist and are
* blanked. If the buffer already contains sufficient data it
* is untouched. Otherwise it is extended. Returns zero on
* success. The skb is freed on error if @free_on_error is true.
*/
static inline int __skb_put_padto(struct sk_buff *skb, unsigned int len,
bool free_on_error)
{
unsigned int size = skb->len;
if (unlikely(size < len)) {
len -= size;
if (__skb_pad(skb, len, free_on_error))
return -ENOMEM;
__skb_put(skb, len);
}
return 0;
}
/**
* skb_put_padto - increase size and pad an skbuff up to a minimal size
* @skb: buffer to pad
@ -2833,15 +2874,7 @@ static inline int skb_padto(struct sk_buff *skb, unsigned int len)
*/
static inline int skb_put_padto(struct sk_buff *skb, unsigned int len)
{
unsigned int size = skb->len;
if (unlikely(size < len)) {
len -= size;
if (skb_pad(skb, len))
return -ENOMEM;
__skb_put(skb, len);
}
return 0;
return __skb_put_padto(skb, len, true);
}
static inline int skb_add_data(struct sk_buff *skb,

13
net/core/skbuff.c
View File

@ -1363,18 +1363,20 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
EXPORT_SYMBOL(skb_copy_expand);
/**
* skb_pad - zero pad the tail of an skb
* __skb_pad - zero pad the tail of an skb
* @skb: buffer to pad
* @pad: space to pad
* @free_on_error: free buffer on error
*
* Ensure that a buffer is followed by a padding area that is zero
* filled. Used by network drivers which may DMA or transfer data
* beyond the buffer end onto the wire.
*
* May return error in out of memory cases. The skb is freed on error.
* May return error in out of memory cases. The skb is freed on error
* if @free_on_error is true.
*/
int skb_pad(struct sk_buff *skb, int pad)
int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error)
{
int err;
int ntail;
@ -1403,10 +1405,11 @@ int skb_pad(struct sk_buff *skb, int pad)
return 0;
free_skb:
kfree_skb(skb);
if (free_on_error)
kfree_skb(skb);
return err;
}
EXPORT_SYMBOL(skb_pad);
EXPORT_SYMBOL(__skb_pad);
/**
* pskb_put - add data to the tail of a potentially fragmented buffer