net: skb->dst accessors

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

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

3 files changed, 10 insertions, 12 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index e2fcc5f10177..34b49a6a22fd 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1693,10 +1693,9 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
                  * If device doesnt need skb->dst, release it right now while
                  * its hot in this cpu cache
                  */
-                if ((dev->priv_flags & IFF_XMIT_DST_RELEASE) && skb->dst) {
-                        dst_release(skb->dst);
-                        skb->dst = NULL;
-                }
+                if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
+                        skb_dst_drop(skb);
+
                 rc = ops->ndo_start_xmit(skb, dev);
                 if (rc == 0)
                         txq_trans_update(txq);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index a1cbce7fdae5..c54229befcfe 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1088,8 +1088,8 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
                         struct neighbour *n1 = neigh;
                         write_unlock_bh(&neigh->lock);
                         /* On shaper/eql skb->dst->neighbour != neigh :( */
-                        if (skb->dst && skb->dst->neighbour)
-                                n1 = skb->dst->neighbour;
+                        if (skb_dst(skb) && skb_dst(skb)->neighbour)
+                                n1 = skb_dst(skb)->neighbour;
                         n1->output(skb);
                         write_lock_bh(&neigh->lock);
                 }
@@ -1182,7 +1182,7 @@ EXPORT_SYMBOL(neigh_compat_output);
 
 int neigh_resolve_output(struct sk_buff *skb)
 {
-        struct dst_entry *dst = skb->dst;
+        struct dst_entry *dst = skb_dst(skb);
         struct neighbour *neigh;
         int rc = 0;
 
@@ -1229,7 +1229,7 @@ EXPORT_SYMBOL(neigh_resolve_output);
 int neigh_connected_output(struct sk_buff *skb)
 {
         int err;
-        struct dst_entry *dst = skb->dst;
+        struct dst_entry *dst = skb_dst(skb);
         struct neighbour *neigh = dst->neighbour;
         struct net_device *dev = neigh->dev;
 
@@ -1298,8 +1298,7 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
                 if (time_before(tbl->proxy_timer.expires, sched_next))
                         sched_next = tbl->proxy_timer.expires;
         }
-        dst_release(skb->dst);
-        skb->dst = NULL;
+        skb_dst_drop(skb);
         dev_hold(skb->dev);
         __skb_queue_tail(&tbl->proxy_queue, skb);
         mod_timer(&tbl->proxy_timer, sched_next);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 8e815e685f28..6adf19ec95cc 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -381,7 +381,7 @@ static void kfree_skbmem(struct sk_buff *skb)
 
 static void skb_release_head_state(struct sk_buff *skb)
 {
-        dst_release(skb->dst);
+        skb_dst_drop(skb);
 #ifdef CONFIG_XFRM
         secpath_put(skb->sp);
 #endif
@@ -521,7 +521,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
         new->transport_header   = old->transport_header;
         new->network_header     = old->network_header;
         new->mac_header         = old->mac_header;
-        new->dst                = dst_clone(old->dst);
+        skb_dst_set(new, dst_clone(skb_dst(old)));
 #ifdef CONFIG_XFRM
         new->sp                 = secpath_get(old->sp);
 #endif