optimize: assert nat type on nat statement helper

Add assert() to helper function to expression from NAT statement.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/src/optimize.c b/src/optimize.c
index 35487190..e0154beb 100644
--- a/src/optimize.c
+++ b/src/optimize.c
@@ -855,6 +855,8 @@ static struct expr *stmt_nat_expr(struct stmt *nat_stmt)
 {
 	struct expr *nat_expr;
 
+	assert(nat_stmt->ops->type == STMT_NAT);
+
 	if (nat_stmt->nat.proto) {
 		nat_expr = concat_expr_alloc(&internal_location);
 		compound_expr_add(nat_expr, expr_get(nat_stmt->nat.addr));
@@ -865,6 +867,8 @@ static struct expr *stmt_nat_expr(struct stmt *nat_stmt)
 		nat_expr = expr_get(nat_stmt->nat.addr);
 	}
 
+	assert(nat_expr);
+
 	return nat_expr;
 }