2 files changed, 49 insertions, 19 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);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 35b07cc33aad..6bf60946698a 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -123,7 +123,20 @@ static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
 
 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst, const void *daddr)
 {
-        return __neigh_lookup_errno(&nd_tbl, daddr, dst->dev);
+        struct neighbour *n = __ipv6_neigh_lookup(&nd_tbl, dst->dev, daddr);
+        if (n)
+                return n;
+        return neigh_create(&nd_tbl, daddr, dst->dev);
+}
+
+static int rt6_bind_neighbour(struct rt6_info *rt)
+{
+        struct neighbour *n = ip6_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
+        if (IS_ERR(n))
+                return PTR_ERR(n);
+        dst_set_neighbour(&rt->dst, n);
+
+        return 0;
 }
 
 static struct dst_ops ip6_dst_ops_template = {
@@ -714,7 +727,6 @@ static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort,
         rt = ip6_rt_copy(ort, daddr);
 
         if (rt) {
-                struct neighbour *neigh;
                 int attempts = !in_softirq();
 
                 if (!(rt->rt6i_flags & RTF_GATEWAY)) {
@@ -734,9 +746,7 @@ static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort,
 #endif
 
         retry:
-                neigh = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway,
-                                             rt->rt6i_dev);
-                if (IS_ERR(neigh)) {
+                if (rt6_bind_neighbour(rt)) {
                         struct net *net = dev_net(rt->rt6i_dev);
                         int saved_rt_min_interval =
                                 net->ipv6.sysctl.ip6_rt_gc_min_interval;
@@ -762,8 +772,6 @@ static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort,
                         dst_free(&rt->dst);
                         return NULL;
                 }
-                dst_set_neighbour(&rt->dst, neigh);
-
         }
 
         return rt;
@@ -1078,7 +1086,7 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
         if (neigh)
                 neigh_hold(neigh);
         else {
-                neigh = __neigh_lookup_errno(&nd_tbl, &fl6->daddr, dev);
+                neigh = ip6_neigh_lookup(&rt->dst, &fl6->daddr);
                 if (IS_ERR(neigh)) {
                         dst_free(&rt->dst);
                         return ERR_CAST(neigh);
@@ -1389,12 +1397,9 @@ int ip6_route_add(struct fib6_config *cfg)
                 rt->rt6i_prefsrc.plen = 0;
 
         if (cfg->fc_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) {
-                struct neighbour *n = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev);
-                if (IS_ERR(n)) {
-                        err = PTR_ERR(n);
+                err = rt6_bind_neighbour(rt);
+                if (err)
                         goto out;
-                }
-                dst_set_neighbour(&rt->dst, n);
         }
 
         rt->rt6i_flags = cfg->fc_flags;
@@ -2057,7 +2062,7 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
         struct net *net = dev_net(idev->dev);
         struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops,
                                             net->loopback_dev, 0);
-        struct neighbour *neigh;
+        int err;
 
         if (!rt) {
                 if (net_ratelimit())
@@ -2079,13 +2084,11 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
                 rt->rt6i_flags |= RTF_ANYCAST;
         else
                 rt->rt6i_flags |= RTF_LOCAL;
-        neigh = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, rt->rt6i_dev);
-        if (IS_ERR(neigh)) {
+        err = rt6_bind_neighbour(rt);
+        if (err) {
                 dst_free(&rt->dst);
-
-                return ERR_CAST(neigh);
+                return ERR_PTR(err);
         }
-        dst_set_neighbour(&rt->dst, neigh);
 
         rt->rt6i_dst.addr = *addr;
         rt->rt6i_dst.plen = 128;