net: add skb frag size accessors

To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.

Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 6e5d4c09e5d7..226faab23603 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -467,7 +467,7 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
 
                 tx->gref = np->grant_tx_ref[id] = ref;
                 tx->offset = frag->page_offset;
-                tx->size = frag->size;
+                tx->size = skb_frag_size(frag);
                 tx->flags = 0;
         }
 
@@ -965,7 +965,7 @@ err:
                 if (rx->status > len) {
                         skb_shinfo(skb)->frags[0].page_offset =
                                 rx->offset + len;
-                        skb_shinfo(skb)->frags[0].size = rx->status - len;
+                        skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status - len);
                         skb->data_len = rx->status - len;
                 } else {
                         __skb_fill_page_desc(skb, 0, NULL, 0, 0);