netfilter: nft_hash: fix symhash with modulus one

[ Upstream commit 28b1d6ef53e3303b90ca8924bb78f31fa527cafb ]

The rule below doesn't work as the kernel raises -ERANGE.

nft add rule netdev nftlb lb01 ip daddr set \
	symhash mod 1 map { 0 : 192.168.0.10 } fwd to "eth0"

This patch allows to use the symhash modulus with one
element, in the same way that the other types of hashes and
algorithms that uses the modulus parameter.

Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index 24f2f7567ddb779af44ee5050df36292f413d4d6..010a565b4000188e189929593d10000691508ea0 100644 (file)
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -131,7 +131,7 @@ static int nft_symhash_init(const struct nft_ctx *ctx,
        priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]);
 
        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)