netfilter: nft_set_hash: fix lookups with fixed size hash on big endian

Call jhash_1word() for the 4-bytes key case from the insertion and
deactivation path, otherwise big endian arch set lookups fail.

Fixes: 446a8268b7f5 ("netfilter: nft_set_hash: add lookup variant for fixed size hashtable")
Reported-by: Florian Westphal <fw@strlen.de>
Tested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 339a9dd1c83210ec800f043c59eb68e4d6659d95..8d5611634a561d378016527f1b7c55e6e619b782 100644 (file)
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -474,6 +474,23 @@ static bool nft_hash_lookup_fast(const struct net *net,
        return false;
 }
 
+static u32 nft_jhash(const struct nft_set *set, const struct nft_hash *priv,
+                    const struct nft_set_ext *ext)
+{
+       const struct nft_data *key = nft_set_ext_key(ext);
+       u32 hash, k1;
+
+       if (set->klen == 4) {
+               k1 = *(u32 *)key;
+               hash = jhash_1word(k1, priv->seed);
+       } else {
+               hash = jhash(key, set->klen, priv->seed);
+       }
+       hash = reciprocal_scale(hash, priv->buckets);
+
+       return hash;
+}
+
 static int nft_hash_insert(const struct net *net, const struct nft_set *set,
                           const struct nft_set_elem *elem,
                           struct nft_set_ext **ext)
@@ -483,8 +500,7 @@ static int nft_hash_insert(const struct net *net, const struct nft_set *set,
        u8 genmask = nft_genmask_next(net);
        u32 hash;
 
-       hash = jhash(nft_set_ext_key(&this->ext), set->klen, priv->seed);
-       hash = reciprocal_scale(hash, priv->buckets);
+       hash = nft_jhash(set, priv, &this->ext);
        hlist_for_each_entry(he, &priv->table[hash], node) {
                if (!memcmp(nft_set_ext_key(&this->ext),
                            nft_set_ext_key(&he->ext), set->klen) &&
@@ -523,8 +539,7 @@ static void *nft_hash_deactivate(const struct net *net,
        u8 genmask = nft_genmask_next(net);
        u32 hash;
 
-       hash = jhash(nft_set_ext_key(&this->ext), set->klen, priv->seed);
-       hash = reciprocal_scale(hash, priv->buckets);
+       hash = nft_jhash(set, priv, &this->ext);
        hlist_for_each_entry(he, &priv->table[hash], node) {
                if (!memcmp(nft_set_ext_key(&this->ext), &elem->key.val,
                            set->klen) &&