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>

3 files changed, 7 insertions, 6 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 1e20b64e646c..1c9bf8b5c30a 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1512,13 +1512,14 @@ alloc_new_skb:
                                 err = -EMSGSIZE;
                                 goto error;
                         }
-                        if (getfrag(from, skb_frag_address(frag)+frag->size,
+                        if (getfrag(from,
+                                    skb_frag_address(frag) + skb_frag_size(frag),
                                     offset, copy, skb->len, skb) < 0) {
                                 err = -EFAULT;
                                 goto error;
                         }
                         sk->sk_sndmsg_off += copy;
-                        frag->size += copy;
+                        skb_frag_size_add(frag, copy);
                         skb->len += copy;
                         skb->data_len += copy;
                         skb->truesize += copy;
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 085727263812..e8762c73b170 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -378,8 +378,8 @@ nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
                 head->next = clone;
                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
                 skb_frag_list_init(head);
-                for (i=0; i<skb_shinfo(head)->nr_frags; i++)
-                        plen += skb_shinfo(head)->frags[i].size;
+                for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+                        plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
                 clone->len = clone->data_len = head->data_len - plen;
                 head->data_len -= clone->len;
                 head->len -= clone->len;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 7b954e2539d0..cc22099ac8b6 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -464,8 +464,8 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
                 head->next = clone;
                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
                 skb_frag_list_init(head);
-                for (i=0; i<skb_shinfo(head)->nr_frags; i++)
-                        plen += skb_shinfo(head)->frags[i].size;
+                for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+                        plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
                 clone->len = clone->data_len = head->data_len - plen;
                 head->data_len -= clone->len;
                 head->len -= clone->len;