From 5620add27f1d80a0a7f3458238a25a25dfc086fb Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Tue, 5 Mar 2019 22:31:05 +0100
Subject: [PATCH] Phasing in icmp6 in the switch

---
 doc/plan.org            |  1 +
 p4app/controller.py     |  4 ++++
 p4src/checksums.p4      |  5 +++++
 p4src/headers.p4        |  2 ++
 p4src/static-mapping.p4 | 19 ++++++++++++++++---
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/doc/plan.org b/doc/plan.org
index d3bf663..ea3bb7b 100644
--- a/doc/plan.org
+++ b/doc/plan.org
@@ -492,6 +492,7 @@ DEBUG:main:INCOMING: <Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x
 **** EAMT/Jool: https://www.jool.mx/en/eamt.html
 **** Solicited node multicast address https://en.wikipedia.org/wiki/Solicited-node_multicast_address
 **** Scapy / IPv6: https://www.idsv6.de/Downloads/IPv6PacketCreationWithScapy.pdf
+**** V1 model: https://github.com/p4lang/p4c/blob/master/p4include/v1model.p4
 * Proposal / task description
 ** Task description for mystudies
 *** High speed NAT64 with P4
diff --git a/p4app/controller.py b/p4app/controller.py
index 27dff5e..e590436 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -175,10 +175,14 @@ class L2Controller(object):
         self.controller.table_clear("v6_addresses")
         for v6addr in self.v6_addresses[self.mode]:
             icmp6_addr = self.gen_ndp_multicast_addr(v6addr)
+            another_addr = v6addr +1
 
             self.controller.table_add("v6_addresses", "controller_reply", [str(v6addr)], [str(self.task['ICMP6_GENERAL'])])
             self.controller.table_add("v6_addresses", "controller_reply", [str(icmp6_addr)], [str(self.task['ICMP6_NS'])])
 
+            # Experimental
+            self.controller.table_add("v6_addresses", "icmp6_echo_reply", [str(another_addr)])
+
     def config_hosts(self):
         """ Assumptions:
         - all routes are networks (no /128 v6 or /32 v4
diff --git a/p4src/checksums.p4 b/p4src/checksums.p4
index d2e20a7..f4ef104 100644
--- a/p4src/checksums.p4
+++ b/p4src/checksums.p4
@@ -22,6 +22,11 @@ control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
 
+        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 (
diff --git a/p4src/headers.p4 b/p4src/headers.p4
index 8cc6c75..165a850 100644
--- a/p4src/headers.p4
+++ b/p4src/headers.p4
@@ -35,6 +35,7 @@ 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;
+const task_t TASK_ICMP6_REPLY    = 4;
 
 
 header ethernet_t {
@@ -132,6 +133,7 @@ struct metadata {
     port_t ingress_port;
     task_t task;
     bit<16> tcp_length;
+    bool calc_icmp6_checksum;
 }
 
 #endif
\ No newline at end of file
diff --git a/p4src/static-mapping.p4 b/p4src/static-mapping.p4
index cb2ac64..ddc9b74 100644
--- a/p4src/static-mapping.p4
+++ b/p4src/static-mapping.p4
@@ -51,6 +51,20 @@ control MyIngress(inout headers hdr,
         hdr.icmp6.type = ICMP6_NA;
     }
 
+    action icmp6_echo_reply() {
+        mac_addr_t mac_tmp = hdr.ethernet.dst_addr;
+        hdr.ethernet.dst_addr = hdr.ethernet.src_addr;
+        hdr.ethernet.src_addr = mac_tmp;
+
+        ipv6_addr_t addr_tmp = hdr.ipv6.dst_addr;
+        hdr.ipv6.dst_addr = hdr.ipv6.src_addr;
+        hdr.ipv6.src_addr = addr_tmp;
+
+        hdr.icmp6.type = ICMP6_ECHO_REPLY;
+
+        meta.calc_icmp6_checksum = true;
+    }
+
     /********************** Reply to NDP for US ***********************************/
     table ndp_answer {
         key = {
@@ -144,6 +158,7 @@ control MyIngress(inout headers hdr,
         actions = {
             controller_debug;
             controller_reply;
+            icmp_echo_reply;
             NoAction;
         }
         size = ADDRESS_TABLE_SIZE;
@@ -165,7 +180,6 @@ control MyIngress(inout headers hdr,
         default_action = NoAction;
     }
 
-
     table v4_networks {
         key = {
             hdr.ipv4.dst_addr: lpm;
@@ -181,11 +195,10 @@ control MyIngress(inout headers hdr,
 	/********************** APPLYING TABLES ***********************************/
     apply {
         if(hdr.ipv6.isValid()) {
-
             /* FIXME: structure / use .hit to do logic */
             // ndp_answer.apply();
-
             //ndp.apply(); /* flood or if it is us - answer */
+
             v6_addresses.apply();
             v6_networks.apply();
         }