rule: reset cache iff there is an existing cache

If genid is unset, then do not reset existing cache. In the kernel,
generation ID is assumed to be always != zero.

This patch fixes:

	nft 'add table x; add chain x y;'

that allow us to send several commands in one single batch from the
command line.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/rule.c b/src/rule.c
index 4334efac..c6560036 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -165,7 +165,9 @@ replay:
 	genid = netlink_genid_get(&ctx);
 	if (genid && genid == cache->genid)
 		return 0;
-	cache_release(cache);
+	if (cache->genid)
+		cache_release(cache);
+
 	ret = cache_init(&ctx, cmd);
 	if (ret < 0) {
 		cache_release(cache);