@@ -778,6 +778,17 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
size = SKB_DATA_ALIGN(size);
+ if (!skb->cloned &&
+ size + sizeof(struct skb_shared_info) <= ksize(skb->head)) {
+ memmove(skb->head + size, skb_shinfo(skb),
+ offsetof(struct skb_shared_info,
+ frags[skb_shinfo(skb)->nr_frags]));
+ memmove(skb->head + nhead, skb->head,
+ skb_tail_pointer(skb) - skb->head);
+ off = nhead;
+ goto adjust_others;
+ }
+
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
if (!data)
goto nodata;
@@ -816,6 +827,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
off = (data + nhead) - skb->head;
skb->head = data;
+adjust_others:
skb->data += off;
#ifdef NET_SKBUFF_DATA_USES_OFFSET
skb->end = size;
If the old memory allocated by kmalloc() is larger than the new requested, pskb_expand_head() doesn't need to allocate a new one, unless the skb is cloned. Signed-off-by: Changli Gao <xiaosuo@gmail.com> --- net/core/skbuff.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html