netfilter: nft_dynset: add timeout extension to template

Otherwise, the newly create element shows no timeout when listing the
ruleset. If the set definition does not specify a default timeout, then
the set element only shows the expiration time, but not the timeout.
This is a problem when restoring a stateful ruleset listing since it
skips the timeout policy entirely.

Fixes: 22fe54d5 ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_dynset.c

@@ -312,8 +312,10 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
 		nft_dynset_ext_add_expr(priv);
 
 	if (set->flags & NFT_SET_TIMEOUT) {
-		if (timeout || set->timeout)
+		if (timeout || set->timeout) {
+			nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
 			nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
+		}
 	}
 
 	priv->timeout = timeout;