X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=net%2Fcore%2Fskbuff.c;h=1e556d31211742d41acb39cbc2c1cd8460e2d3b0;hb=f27b433ef32a77c8cb76f018507453df7c03e552;hp=6087013396208e17e48d06047301eed6489a447c;hpb=f4df39cbdd9e9ab615e80148cc271db22a8508ad;p=linux-2.6-omap-h63xx.git

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 60870133962..1e556d31211 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -200,7 +200,9 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
 		goto nodata;
 
 	/*
-	 * See comment in sk_buff definition, just before the 'tail' member
+	 * Only clear those fields we need to clear, not those that we will
+	 * actually initialise below. Hence, don't put any more fields after
+	 * the tail pointer in struct sk_buff!
 	 */
 	memset(skb, 0, offsetof(struct sk_buff, tail));
 	skb->truesize = size + sizeof(struct sk_buff);
@@ -263,6 +265,28 @@ 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 +881,78 @@ 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.
  */
 
@@ -1349,6 +1445,7 @@ done:
 
 	if (spd.nr_pages) {
 		int ret;
+		struct sock *sk = __skb->sk;
 
 		/*
 		 * Drop the socket lock, otherwise we have reverse
@@ -1359,9 +1456,9 @@ done:
 		 * we call into ->sendpage() with the i_mutex lock held
 		 * and networking will grab the socket lock.
 		 */
-		release_sock(__skb->sk);
+		release_sock(sk);
 		ret = splice_to_pipe(pipe, &spd);
-		lock_sock(__skb->sk);
+		lock_sock(sk);
 		return ret;
 	}
 
@@ -1766,7 +1863,7 @@ 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);
 }