src: add support to flush sets

You can use this new command to remove all existing elements in a set:

 # nft flush set filter xyz

After this command, the set 'xyz' in table 'filter' becomes empty.

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

1 files changed, 8 insertions, 1 deletions

diff --git a/src/netlink.c b/src/netlink.c
index f8e600ff..714df4e8 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -1374,7 +1374,8 @@ static int netlink_del_setelems_batch(struct netlink_ctx *ctx,
 	int err;
 
 	nls = alloc_nftnl_set(h);
-	alloc_setelem_cache(expr, nls);
+	if (expr)
+		alloc_setelem_cache(expr, nls);
 	netlink_dump_set(nls);
 
 	err = mnl_nft_setelem_batch_del(nls, 0, ctx->seqnum);
@@ -1406,6 +1407,12 @@ static int netlink_del_setelems_compat(struct netlink_ctx *ctx,
 	return err;
 }
 
+int netlink_flush_setelems(struct netlink_ctx *ctx, const struct handle *h,
+			   const struct location *loc)
+{
+	return netlink_del_setelems_batch(ctx, h, NULL);
+}
+
 static struct expr *netlink_parse_concat_elem(const struct datatype *dtype,
 					      struct expr *data)
 {