Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[karo-tx-linux.git] / net / core / skbuff.c

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 2f6babd5a5703061f67e007d0395a9bc8e6ab607..7dc05ecf040a374a5c5a1d26af49f73856968bf7 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -189,6 +189,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
         * aligned memory blocks, unless SLUB/SLAB debug is enabled.
         * Both skb->head and skb_shared_info are cache line aligned.
         */
+       size = SKB_DATA_ALIGN(size);
        size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
        data = kmalloc_node_track_caller(size, gfp_mask, node);
        if (!data)
@@ -243,6 +244,55 @@ nodata:
 }
 EXPORT_SYMBOL(__alloc_skb);
 
+/**
+ * build_skb - build a network buffer
+ * @data: data buffer provided by caller
+ *
+ * Allocate a new &sk_buff. Caller provides space holding head and
+ * skb_shared_info. @data must have been allocated by kmalloc()
+ * The return is the new skb buffer.
+ * On a failure the return is %NULL, and @data is not freed.
+ * Notes :
+ *  Before IO, driver allocates only data buffer where NIC put incoming frame
+ *  Driver should add room at head (NET_SKB_PAD) and
+ *  MUST add room at tail (SKB_DATA_ALIGN(skb_shared_info))
+ *  After IO, driver calls build_skb(), to allocate sk_buff and populate it
+ *  before giving packet to stack.
+ *  RX rings only contains data buffers, not full skbs.
+ */
+struct sk_buff *build_skb(void *data)
+{
+       struct skb_shared_info *shinfo;
+       struct sk_buff *skb;
+       unsigned int size;
+
+       skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
+       if (!skb)
+               return NULL;
+
+       size = ksize(data) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+       memset(skb, 0, offsetof(struct sk_buff, tail));
+       skb->truesize = SKB_TRUESIZE(size);
+       atomic_set(&skb->users, 1);
+       skb->head = data;
+       skb->data = data;
+       skb_reset_tail_pointer(skb);
+       skb->end = skb->tail + size;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+       skb->mac_header = ~0U;
+#endif
+
+       /* make sure we initialize shinfo sequentially */
+       shinfo = skb_shinfo(skb);
+       memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
+       atomic_set(&shinfo->dataref, 1);
+       kmemcheck_annotate_variable(shinfo->destructor_arg);
+
+       return skb;
+}
+EXPORT_SYMBOL(build_skb);
+
 /**
  *     __netdev_alloc_skb - allocate an skbuff for rx on a specific device
  *     @dev: network device to receive on
@@ -2620,7 +2670,7 @@ EXPORT_SYMBOL_GPL(skb_pull_rcsum);
  *     a pointer to the first in a list of new skbs for the segments.
  *     In case of error it returns ERR_PTR(err).
  */
-struct sk_buff *skb_segment(struct sk_buff *skb, u32 features)
+struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
 {
        struct sk_buff *segs = NULL;
        struct sk_buff *tail = NULL;