1 files changed, 61 insertions, 2 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index ca1ccdf..7f7bb1a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -263,6 +263,26 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
 	return skb;
 }
 
+struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
+{
+	int node = dev->dev.parent ? dev_to_node(dev->dev.parent) : -1;
+	struct page *page;
+
+	page = alloc_pages_node(node, gfp_mask, 0);
+	return page;
+}
+EXPORT_SYMBOL(__netdev_alloc_page);
+
+void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
+		int size)
+{
+	skb_fill_page_desc(skb, i, page, off, size);
+	skb->len += size;
+	skb->data_len += size;
+	skb->truesize += size;
+}
+EXPORT_SYMBOL(skb_add_rx_frag);
+
 /**
  *	dev_alloc_skb - allocate an skbuff for receiving
  *	@length: length to allocate
@@ -363,8 +383,7 @@ static void kfree_skbmem(struct sk_buff *skb)
 	}
 }
 
-/* Free everything but the sk_buff shell. */
-static void skb_release_all(struct sk_buff *skb)
+static void skb_release_head_state(struct sk_buff *skb)
 {
 	dst_release(skb->dst);
 #ifdef CONFIG_XFRM
@@ -388,6 +407,12 @@ static void skb_release_all(struct sk_buff *skb)
 	skb->tc_verd = 0;
 #endif
 #endif
+}
+
+/* Free everything but the sk_buff shell. */
+static void skb_release_all(struct sk_buff *skb)
+{
+	skb_release_head_state(skb);
 	skb_release_data(skb);
 }
 
@@ -424,6 +449,38 @@ void kfree_skb(struct sk_buff *skb)
 	__kfree_skb(skb);
 }
 
+int skb_recycle_check(struct sk_buff *skb, int skb_size)
+{
+	struct skb_shared_info *shinfo;
+
+	if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
+		return 0;
+
+	skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
+	if (skb_end_pointer(skb) - skb->head < skb_size)
+		return 0;
+
+	if (skb_shared(skb) || skb_cloned(skb))
+		return 0;
+
+	skb_release_head_state(skb);
+	shinfo = skb_shinfo(skb);
+	atomic_set(&shinfo->dataref, 1);
+	shinfo->nr_frags = 0;
+	shinfo->gso_size = 0;
+	shinfo->gso_segs = 0;
+	shinfo->gso_type = 0;
+	shinfo->ip6_frag_id = 0;
+	shinfo->frag_list = NULL;
+
+	memset(skb, 0, offsetof(struct sk_buff, tail));
+	skb_reset_tail_pointer(skb);
+	skb->data = skb->head + NET_SKB_PAD;
+
+	return 1;
+}
+EXPORT_SYMBOL(skb_recycle_check);
+
 static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 {
 	new->tstamp		= old->tstamp;
@@ -701,6 +758,8 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 #endif
 	long off;
 
+	BUG_ON(nhead < 0);
+
 	if (skb_shared(skb))
 		BUG();