From ea1873c14c70916ad4c304ac3f2560bfaca7195d Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Mon, 4 Mar 2019 16:23:28 +0100
Subject: [PATCH] Use types for signalling expected action

---
 p4app/controller.py     | 15 ++++++++++++---
 p4src/headers.p4        | 16 ++++++++++++----
 p4src/parsers.p4        |  4 ++++
 p4src/static-mapping.p4 | 10 +++++-----
 4 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/p4app/controller.py b/p4app/controller.py
index ab78600..e8e9c30 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -27,7 +27,10 @@ log = logging.getLogger("main")
 
 class CpuHeader(Packet):
     name = 'CpuPacket'
-    fields_desc = [BitField('ingress_port', 0, 16)]
+    fields_desc = [
+        BitField('task',0,8)
+        BitField('ingress_port', 0, 16)
+    ]
 
 
 class L2Controller(object):
@@ -35,6 +38,12 @@ class L2Controller(object):
         # Command line mapping
         self.modes = ['base', 'router']
 
+        self.task = {
+            'ICMP6_NS': 1,
+            'ICMP6_GENERAL': 2,
+            'DEBUG': 3
+        }
+
         self.info={}
         self.info['ndp_multicast'] = ipaddress.ip_network("ff02::1:ff00:0/104")
 
@@ -158,8 +167,8 @@ class L2Controller(object):
         for v6addr in self.v6_addresses[self.mode]:
             icmp6_addr = self.gen_ndp_multicast_addr(v6addr)
 
-            self.controller.table_add("v6_addresses", "controller_reply", [str(v6addr)])
-            self.controller.table_add("v6_addresses", "controller_reply", [str(icmp6_addr)])
+            self.controller.table_add("v6_addresses", "controller_reply", [str(self.task['ICMP6_GENERAL'])], [str(v6addr)])
+            self.controller.table_add("v6_addresses", "controller_reply", [str(self.task['ICMP6_NS'])], [str(icmp6_addr)])
 
     def config_hosts(self):
         """ Assumptions:
diff --git a/p4src/headers.p4 b/p4src/headers.p4
index fb45d31..024eced 100644
--- a/p4src/headers.p4
+++ b/p4src/headers.p4
@@ -8,8 +8,9 @@
 typedef bit<48>  mac_addr_t;
 typedef bit<32>  ipv4_addr_t;
 typedef bit<128> ipv6_addr_t;
-typedef bit<9>   port_t;
+typedef bit<9>  port_t;
 typedef bit<16>  mcast_t;
+typedef bit<8> task_t;
 
 
 const bit<16> TYPE_IPV4  = 0x0800;
@@ -31,6 +32,10 @@ const bit<8>  ICMP6_NS           = 135;
 const bit<8>  ICMP6_NA           = 136;
 
 
+const task_t TASK_ICMP6_NS = 1;
+const task_t TASK_ICMP6_GENERAL = 2;
+const task_t TASK_DEBUG = 3;
+
 
 header ethernet_t {
     mac_addr_t dst_addr;
@@ -106,6 +111,10 @@ header icmp_t {
     bit<32> rest;
 }
 
+header cpu_t {
+    port_t ingress_port;
+    task_t task;
+}
 
 struct headers {
     ethernet_t       ethernet;
@@ -115,12 +124,11 @@ struct headers {
     udp_t	         udp;
     icmp6_t          icmp6;
     icmp_t           icmp;
+    cpu_t            cpu;
 }
 
 struct metadata {
-    bit<16> tcp_length;
-    bit<16> ethertype; /* we use this, if we are cloning */
-    bit<1> ether_modified;
+    task_t task;
 }
 
 #endif
\ No newline at end of file
diff --git a/p4src/parsers.p4 b/p4src/parsers.p4
index 6f6f768..1c7cfd4 100644
--- a/p4src/parsers.p4
+++ b/p4src/parsers.p4
@@ -75,6 +75,10 @@ parser MyParser(packet_in packet,
 
 control MyDeparser(packet_out packet, in headers hdr) {
     apply {
+        /* only if information is sent to the controller */
+        packet.emit(hdr.cpu);
+
+        /* always */
         packet.emit(hdr.ethernet);
 
         /* either */
diff --git a/p4src/static-mapping.p4 b/p4src/static-mapping.p4
index a61eaf3..3b8d39e 100644
--- a/p4src/static-mapping.p4
+++ b/p4src/static-mapping.p4
@@ -27,12 +27,12 @@ control MyIngress(inout headers hdr,
 	}
 
     action controller_debug() {
-        meta.ether_modified = 1;
-        meta.ethertype = TYPE_DEBUG;
+        meta.task = TASK_DEBUG;
         clone3(CloneType.I2E, 100, meta);
     }
 
-    action controller_reply() {
+    action controller_reply(task_t task) {
+        meta.task = task;
         clone3(CloneType.I2E, 100, meta);
     }
 
@@ -203,7 +203,8 @@ control MyEgress(inout headers hdr,
 	apply {
         // ingress clone
         if (standard_metadata.instance_type == 1 && meta.ether_modified == 1){
-            hdr.ethernet.ethertype = meta.ethertype;
+            hdr.cpu.setValid();
+            hdr.cpu.task = meta.task;
         }
 	}
 }
@@ -226,7 +227,6 @@ MyDeparser()
         // hdr.tcp.setValid();
 
 
-        //     hdr.cpu.setValid();
         //     hdr.cpu.srcAddr = hdr.ethernet.srcAddr;
         //     hdr.cpu.ingress_port = (bit<16>)meta.ingress_port;