netfilter: nft_dynset: relax superfluous check on set updates

stable inclusion
from stable-5.10.80
commit 740a794e01c5f75b22044a06bfd16183baf2c352
bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=740a794e01c5f75b22044a06bfd16183baf2c352

--------------------------------

[ Upstream commit 7b139489 ]

Relax this condition to make add and update commands idempotent for sets
with no timeout. The eval function already checks if the set element
timeout is available and updates it if the update command is used.

Fixes: 22fe54d5 ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/netfilter/nft_dynset.c

@@ -141,17 +141,8 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
 		return -EBUSY;
 
 	priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
-	switch (priv->op) {
-	case NFT_DYNSET_OP_ADD:
-	case NFT_DYNSET_OP_DELETE:
-		break;
-	case NFT_DYNSET_OP_UPDATE:
-		if (!(set->flags & NFT_SET_TIMEOUT))
-			return -EOPNOTSUPP;
-		break;
-	default:
+	if (priv->op > NFT_DYNSET_OP_DELETE)
 		return -EOPNOTSUPP;
-	}
 
 	timeout = 0;
 	if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {