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>

diff --git a/src/optimize.c b/src/optimize.c
index 3548719031e60425645995cf00f4f15084c25e07..e0154beb556d202248722257f627a8d5630b5873 100644 (file)
--- 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;
 }