ipv6: Create fast inline ipv6 neigh lookup just like ipv4.

Also, create and use an rt6_bind_neighbour() in net/ipv6/route.c to
consolidate some common logic.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 0 deletions

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index e9c30023b784..e3133c23980e 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -89,6 +89,33 @@ static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, _
                 (p32[3] * hash_rnd[3]));
 }
 
+static inline struct neighbour *__ipv6_neigh_lookup(struct neigh_table *tbl, struct net_device *dev, const void *pkey)
+{
+        struct neigh_hash_table *nht;
+        const u32 *p32 = pkey;
+        struct neighbour *n;
+        u32 hash_val;
+
+        rcu_read_lock_bh();
+        nht = rcu_dereference_bh(tbl->nht);
+        hash_val = ndisc_hashfn(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
+        for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
+             n != NULL;
+             n = rcu_dereference_bh(n->next)) {
+                u32 *n32 = (u32 *) n->primary_key;
+                if (n->dev == dev &&
+                    ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
+                     (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0) {
+                        if (!atomic_inc_not_zero(&n->refcnt))
+                                n = NULL;
+                        break;
+                }
+        }
+        rcu_read_unlock_bh();
+
+        return n;
+}
+
 extern int                      ndisc_init(void);
 
 extern void                     ndisc_cleanup(void);