netfilter: nft_numgen: enable hashing of one element

The modulus in the hash function was limited to > 1 as initially
there was no sense to create a hashing of just one element.

Nevertheless, there are certain cases specially for load balancing
where this case needs to be addressed.

This patch fixes the following error.

Error: Could not process rule: Numerical result out of range
add rule ip nftlb lb01 dnat to jhash ip saddr mod 1 map { 0: 192.168.0.10 }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The solution comes to force the hash to 0 when the modulus is 1.

Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>

diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index 24f2f7567ddb779af44ee5050df36292f413d4d6..e235c17f1b8b7211d33d95f5a348bc7a6ed2046f 100644 (file)
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -97,7 +97,7 @@ static int nft_jhash_init(const struct nft_ctx *ctx,
        priv->len = len;
 
        priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS]));
-       if (priv->modulus <= 1)
+       if (priv->modulus < 1)
                return -ERANGE;
 
        if (priv->offset + priv->modulus - 1 < priv->offset)