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 <da...@davemloft.net>
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
include/linux/skbuff.h | 41 +++++++++++++++++++++++++++++++++++++----
net/core/skbuff.c | 13 ++++++++-----
2 files changed, 45 insertions(+), 9 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index dbe29b6c9bd6..d67a8182e5eb 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -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,
@@ -2825,25 +2841,42 @@ static inline int skb_padto(struct sk_buff *skb,
unsigned int len)
* 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.
+ * 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)
+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))
+ 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
+ * @len: minimal length
+ *
+ * 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.
+ */
+static inline int skb_put_padto(struct sk_buff *skb, unsigned int len)
+{
+ return __skb_put_padto(skb, len, true);
+}
+
static inline int skb_add_data(struct sk_buff *skb,
struct iov_iter *from, int copy)
{
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f990eb8b30a9..e07556606284 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -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
--
2.9.3
