[NET] NEIGHBOUR: Extract hash/lookup functions for pneigh entries.

Extract hash function for pneigh entries from pneigh_lookup(),
__pneigh_lookup() and pneigh_delete() as pneigh_hash().
Extract core of pneigh_lookup() and __pneigh_lookup() as
__pneigh_lookup_1().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 29 insertions, 32 deletions

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index d4fae81e5d0d..75075c303c44 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -472,26 +472,40 @@ out_neigh_release:
 }
 EXPORT_SYMBOL(neigh_create);
 
-struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
-                struct net *net, const void *pkey, struct net_device *dev)
+static u32 pneigh_hash(const void *pkey, int key_len)
 {
-        struct pneigh_entry *n;
-        int key_len = tbl->key_len;
         u32 hash_val = *(u32 *)(pkey + key_len - 4);
-
         hash_val ^= (hash_val >> 16);
         hash_val ^= hash_val >> 8;
         hash_val ^= hash_val >> 4;
         hash_val &= PNEIGH_HASHMASK;
+        return hash_val;
+}
 
-        for (n = tbl->phash_buckets[hash_val]; n; n = n->next) {
+static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n,
+                                              struct net *net,
+                                              const void *pkey,
+                                              int key_len,
+                                              struct net_device *dev)
+{
+        while (n) {
                 if (!memcmp(n->key, pkey, key_len) &&
-                    (pneigh_net(n) == net) &&
+                    net_eq(pneigh_net(n), net) &&
                     (n->dev == dev || !n->dev))
-                        break;
+                        return n;
+                n = n->next;
         }
+        return NULL;
+}
 
-        return n;
+struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
+                struct net *net, const void *pkey, struct net_device *dev)
+{
+        int key_len = tbl->key_len;
+        u32 hash_val = pneigh_hash(pkey, key_len);
+
+        return __pneigh_lookup_1(tbl->phash_buckets[hash_val],
+                                 net, pkey, key_len, dev);
 }
 EXPORT_SYMBOL_GPL(__pneigh_lookup);
 
@@ -501,26 +515,14 @@ struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 {
         struct pneigh_entry *n;
         int key_len = tbl->key_len;
-        u32 hash_val = *(u32 *)(pkey + key_len - 4);
-
-        hash_val ^= (hash_val >> 16);
-        hash_val ^= hash_val >> 8;
-        hash_val ^= hash_val >> 4;
-        hash_val &= PNEIGH_HASHMASK;
+        u32 hash_val = pneigh_hash(pkey, key_len);
 
         read_lock_bh(&tbl->lock);
-
-        for (n = tbl->phash_buckets[hash_val]; n; n = n->next) {
-                if (!memcmp(n->key, pkey, key_len) &&
-                    net_eq(pneigh_net(n), net) &&
-                    (n->dev == dev || !n->dev)) {
-                        read_unlock_bh(&tbl->lock);
-                        goto out;
-                }
-        }
+        n = __pneigh_lookup_1(tbl->phash_buckets[hash_val],
+                              net, pkey, key_len, dev);
         read_unlock_bh(&tbl->lock);
-        n = NULL;
-        if (!creat)
+
+        if (n || !creat)
                 goto out;
 
         ASSERT_RTNL();
@@ -561,12 +563,7 @@ int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
 {
         struct pneigh_entry *n, **np;
         int key_len = tbl->key_len;
-        u32 hash_val = *(u32 *)(pkey + key_len - 4);
-
-        hash_val ^= (hash_val >> 16);
-        hash_val ^= hash_val >> 8;
-        hash_val ^= hash_val >> 4;
-        hash_val &= PNEIGH_HASHMASK;
+        u32 hash_val = pneigh_hash(pkey, key_len);
 
         write_lock_bh(&tbl->lock);
         for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;