From 0bd12260c6699a6e8f864ab5dfa75c3e8ec12d71 Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Tue, 5 Mar 2019 22:42:51 +0100
Subject: [PATCH] Re-introduce checksumming in p4

---
 p4src/checksums.p4 | 31 ++++++++++++-------------------
 1 file changed, 12 insertions(+), 19 deletions(-)

diff --git a/p4src/checksums.p4 b/p4src/checksums.p4
index aa10451..6f087da 100644
--- a/p4src/checksums.p4
+++ b/p4src/checksums.p4
@@ -21,26 +21,19 @@ control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
 
 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
+        bit<32> icmp6_len = (bit<32>) hdr.ipv6.payload_length;
 
-        if(meta.calc_icmp6_checksum) {
-            hdr.icmp6.checksum = 42; /* must be correct */
-        }
-
-        // verify_checksum_with_payload<T, O>(in bool condition, in T data, inout O checksum, HashAlgorithm algo);
-        // GRRRRR bit<32> icmp6_len = 32; /* for icmp6 NS */
-
-		// GRRRRR update_checksum (
-		// GRRRRR 	hdr.icmp6.isValid(),
-		// GRRRRR 	{
-        // GRRRRR         hdr.ipv6.src_addr,         /* 128 */
-		// GRRRRR 		hdr.ipv6.dst_addr,         /* 128 */
-        // GRRRRR         icmp6_len,                 /* 32 */
-        // GRRRRR         24w0,                      /* 24 0's */
-        // GRRRRR         PROTO_ICMP6                /* 8 */
-        // GRRRRR     },
-        // GRRRRR     hdr.icmp6.checksum,
-        // GRRRRR     HashAlgorithm.csum16
-        // GRRRRR );
+        update_checksum_with_payload(meta.calc_icmp6_checksum,
+		 	{
+                hdr.ipv6.src_addr,         /* 128 */
+		 		hdr.ipv6.dst_addr,         /* 128 */
+                icmp6_len,                 /* 32 */
+                24w0,                      /* 24 0's */
+                PROTO_ICMP6                /* 8 */
+            },
+            hdr.icmp6.checksum,
+            HashAlgorithm.csum16
+        );
     }
 }