From c6b1463e17883eacdf81846284c57cf6a2e9151b Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Mon, 25 Mar 2019 13:02:09 +0100
Subject: [PATCH] Debug missing checksum, introduce new field

---
 doc/plan.org            | 6 +++++-
 p4src/checksums.p4      | 4 ++--
 p4src/headers.p4        | 1 +
 p4src/static-mapping.p4 | 4 ++--
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/doc/plan.org b/doc/plan.org
index 0e75bf6..0ce8e37 100644
--- a/doc/plan.org
+++ b/doc/plan.org
@@ -415,7 +415,11 @@ DEBUG:main:reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=
 
 That looks like NDP is not working again. Why: checksum seems to be
 incorrect according to wireshark. Why? Checksum is the SAME as in the
-request -> probably not updated.
+request -> probably not updated. After inserting marker: it's clear
+that the checksum code DOES NOT work on the task field!
+
+Problem: task field might be overriden for controller use in different
+table -> need different task field!
 
 *** TODO Get p4 VM / vagrant running
 **** DONE install libvirtd-daemon
diff --git a/p4src/checksums.p4 b/p4src/checksums.p4
index 9e05953..1f38867 100644
--- a/p4src/checksums.p4
+++ b/p4src/checksums.p4
@@ -21,7 +21,7 @@ control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
 
 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
-        update_checksum_with_payload(meta.task == TASK_CHECKSUM_ICMP6,
+        update_checksum_with_payload(meta.switch_task == TASK_CHECKSUM_ICMP6,
 		 	{
                 hdr.ipv6.src_addr,         /* 128 */
 		 		hdr.ipv6.dst_addr,         /* 128 */
@@ -36,7 +36,7 @@ control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
         );
 
         /* checksumming for icmp6_na_ns_option */
-        update_checksum_with_payload(meta.task == TASK_CHECKSUM_ICMP6_NA,
+        update_checksum_with_payload(meta.switch_task == TASK_CHECKSUM_ICMP6_NA,
 		 	{
                 hdr.ipv6.src_addr,         /* 128 */
 		 		hdr.ipv6.dst_addr,         /* 128 */
diff --git a/p4src/headers.p4 b/p4src/headers.p4
index a60ceb0..9fbcf96 100644
--- a/p4src/headers.p4
+++ b/p4src/headers.p4
@@ -166,6 +166,7 @@ struct headers {
 struct metadata {
     port_t ingress_port;
     task_t task;
+    task_t switch_task;
     bit<16> tcp_length;
     bit<32> cast_length;
 }
diff --git a/p4src/static-mapping.p4 b/p4src/static-mapping.p4
index 7f91a7e..70b5bb3 100644
--- a/p4src/static-mapping.p4
+++ b/p4src/static-mapping.p4
@@ -197,7 +197,7 @@ control MyIngress(inout headers hdr,
         */
 
         /* checksum trigger / content */
-        meta.task = TASK_CHECKSUM_ICMP6_NA;
+        meta.switch_task = TASK_CHECKSUM_ICMP6_NA;
         meta.cast_length = (bit<32>) hdr.ipv6.payload_length;
     }
 
@@ -212,7 +212,7 @@ control MyIngress(inout headers hdr,
 
         hdr.icmp6.type = ICMP6_ECHO_REPLY;
 
-        meta.task = TASK_CHECKSUM_ICMP6;
+        meta.switch_task = TASK_CHECKSUM_ICMP6;
         meta.cast_length = (bit<32>) hdr.ipv6.payload_length;
     }