evaluate: don't eval unary arguments

When a unary expression is inserted to implement a byte-order
conversion, the expression being converted has already been evaluated
and so `expr_evaluate_unary` doesn't need to do so.

This is required by {ct|meta} statements with bitwise operations, which
might result in byteorder conversion of the expression.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/src/evaluate.c b/src/evaluate.c
index b0a7fa76..e0263f97 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1198,12 +1198,10 @@ static int expr_evaluate_range(struct eval_ctx *ctx, struct expr **expr)
  */
 static int expr_evaluate_unary(struct eval_ctx *ctx, struct expr **expr)
 {
-	struct expr *unary = *expr, *arg;
+	struct expr *unary = *expr, *arg = unary->arg;
 	enum byteorder byteorder;
 
-	if (expr_evaluate(ctx, &unary->arg) < 0)
-		return -1;
-	arg = unary->arg;
+	/* unary expression arguments has already been evaluated. */
 
 	assert(!expr_is_constant(arg));
 	assert(expr_basetype(arg)->type == TYPE_INTEGER);