evaluate: don't evaluate payloads twice.

Payload munging means that evaluation of payload expressions may not be
idempotent.  Add a flag to prevent them from being evaluated more than
once.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/expression.h b/include/expression.h
index 62fbbbb5..87c39e5d 100644
--- a/include/expression.h
+++ b/include/expression.h
@@ -300,6 +300,7 @@ struct expr {
 			enum proto_bases		base;
 			unsigned int			offset;
 			bool				is_raw;
+			bool				evaluated;
 		} payload;
 		struct {
 			/* EXPR_EXTHDR */