1 files changed, 95 insertions, 1 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 608701339620..4fe605fa6f8a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -263,6 +263,28 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
         return skb;
 }
 
+/**
+ *      dev_alloc_skb - allocate an skbuff for receiving
+ *      @length: length to allocate
+ *
+ *      Allocate a new &sk_buff and assign it a usage count of one. The
+ *      buffer has unspecified headroom built in. Users should allocate
+ *      the headroom they think they need without accounting for the
+ *      built in space. The built in space is used for optimisations.
+ *
+ *      %NULL is returned if there is no free memory. Although this function
+ *      allocates memory it can be called from an interrupt.
+ */
+struct sk_buff *dev_alloc_skb(unsigned int length)
+{
+        /*
+         * There is more code here than it seems:
+         * __dev_alloc_skb is an inline
+         */
+        return __dev_alloc_skb(length, GFP_ATOMIC);
+}
+EXPORT_SYMBOL(dev_alloc_skb);
+
 static void skb_drop_list(struct sk_buff **listp)
 {
         struct sk_buff *list = *listp;
@@ -857,6 +879,78 @@ free_skb:
         return err;
 }
 
+/**
+ *      skb_put - add data to a buffer
+ *      @skb: buffer to use
+ *      @len: amount of data to add
+ *
+ *      This function extends the used data area of the buffer. If this would
+ *      exceed the total buffer size the kernel will panic. A pointer to the
+ *      first byte of the extra data is returned.
+ */
+unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
+{
+        unsigned char *tmp = skb_tail_pointer(skb);
+        SKB_LINEAR_ASSERT(skb);
+        skb->tail += len;
+        skb->len  += len;
+        if (unlikely(skb->tail > skb->end))
+                skb_over_panic(skb, len, __builtin_return_address(0));
+        return tmp;
+}
+EXPORT_SYMBOL(skb_put);
+
+/**
+ *      skb_push - add data to the start of a buffer
+ *      @skb: buffer to use
+ *      @len: amount of data to add
+ *
+ *      This function extends the used data area of the buffer at the buffer
+ *      start. If this would exceed the total buffer headroom the kernel will
+ *      panic. A pointer to the first byte of the extra data is returned.
+ */
+unsigned char *skb_push(struct sk_buff *skb, unsigned int len)
+{
+        skb->data -= len;
+        skb->len  += len;
+        if (unlikely(skb->data<skb->head))
+                skb_under_panic(skb, len, __builtin_return_address(0));
+        return skb->data;
+}
+EXPORT_SYMBOL(skb_push);
+
+/**
+ *      skb_pull - remove data from the start of a buffer
+ *      @skb: buffer to use
+ *      @len: amount of data to remove
+ *
+ *      This function removes data from the start of a buffer, returning
+ *      the memory to the headroom. A pointer to the next data in the buffer
+ *      is returned. Once the data has been pulled future pushes will overwrite
+ *      the old data.
+ */
+unsigned char *skb_pull(struct sk_buff *skb, unsigned int len)
+{
+        return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
+}
+EXPORT_SYMBOL(skb_pull);
+
+/**
+ *      skb_trim - remove end from a buffer
+ *      @skb: buffer to alter
+ *      @len: new length
+ *
+ *      Cut the length of a buffer down by removing data from the tail. If
+ *      the buffer is already under the length specified it is not modified.
+ *      The skb must be linear.
+ */
+void skb_trim(struct sk_buff *skb, unsigned int len)
+{
+        if (skb->len > len)
+                __skb_trim(skb, len);
+}
+EXPORT_SYMBOL(skb_trim);
+
 /* Trims skb to length len. It can change skb pointers.
  */
 
@@ -1766,7 +1860,7 @@ void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head
         unsigned long flags;
 
         spin_lock_irqsave(&list->lock, flags);
-        __skb_append(old, newsk, list);
+        __skb_queue_after(list, old, newsk);
         spin_unlock_irqrestore(&list->lock, flags);
 }