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

[sfrench/cifs-2.6.git] / include / linux / skbuff.h

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index dbe29b6c9bd6097b4a7e5763ad39d26921780270..d67a8182e5eb2177d978ca8a5effeaf6bd579394 100644 (file)
--- 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)
 {