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, 4 insertions, 5 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 4c0da24fb649..132be081cd00 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -813,7 +813,7 @@ new_segment:
                         goto wait_for_memory;
 
                 if (can_coalesce) {
-                        skb_shinfo(skb)->frags[i - 1].size += copy;
+                        skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
                 } else {
                         get_page(page);
                         skb_fill_page_desc(skb, i, page, offset, copy);
@@ -1058,8 +1058,7 @@ new_segment:
 
                                 /* Update the skb. */
                                 if (merge) {
-                                        skb_shinfo(skb)->frags[i - 1].size +=
-                                                                        copy;
+                                        skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
                                 } else {
                                         skb_fill_page_desc(skb, i, page, off, copy);
                                         if (TCP_PAGE(sk)) {
@@ -3031,8 +3030,8 @@ int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
         for (i = 0; i < shi->nr_frags; ++i) {
                 const struct skb_frag_struct *f = &shi->frags[i];
                 struct page *page = skb_frag_page(f);
-                sg_set_page(&sg, page, f->size, f->page_offset);
-                if (crypto_hash_update(desc, &sg, f->size))
+                sg_set_page(&sg, page, skb_frag_size(f), f->page_offset);
+                if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
                         return 1;
         }