From 9fdc909838219065d3b6680ba8a2e7860c21c96f Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Wed, 10 Jul 2019 14:49:23 +0200
Subject: [PATCH] put the diff into the checksum

---
 p4src/checksum_diff.p4 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/p4src/checksum_diff.p4 b/p4src/checksum_diff.p4
index ee91c41..8c626ad 100644
--- a/p4src/checksum_diff.p4
+++ b/p4src/checksum_diff.p4
@@ -197,7 +197,8 @@ control MyIngress(inout headers hdr,
                     v4sum();
                     v6sum();
                     bit<16> diff = meta.v6sum - meta.v4sum;
-                    hdr.udp.checksum = hdr.udp.checksum + diff;
+                    # hdr.udp.checksum = hdr.udp.checksum + diff;
+                    hdr.udp.checksum = diff;
 
                     #else
                     meta.chk_udp_v6 = 1;