From 6895a6ab340bb0ab65037e4dca799f413a57e8f1 Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Tue, 26 Feb 2019 15:08:53 +0100
Subject: [PATCH] Create multicast groups for NDP support

---
 doc/plan.org        | 10 ++++++++++
 p4app/controller.py | 17 +++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/doc/plan.org b/doc/plan.org
index a266c93..7f339d2 100644
--- a/doc/plan.org
+++ b/doc/plan.org
@@ -74,6 +74,14 @@
 ***** TODO For other nodes -> multicast
 ***** TODO Maybe implement link local addresses (missing at the moment)
 ****** ff02::/??
+****** rfc4861
+"Neighbor Solicitation messages are multicast to the  solicited-node
+multicast address of the target address."
+****** multicasting / groups
+******* create a group ("node") that contains "all other" ports
+******* create a multicast group with an ID
+******* associate the "node" with the multicast group ID
+
 **** TODO Make switch answer icmp6 echo request for
 **** TODO Make switch answer icmp echo request for
 **** TODO Add default route for v6 and v4 hosts
@@ -213,8 +221,10 @@ DEBUG:main:INCOMING: <Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x
 **** RFC 6586 for deployment experiences using Stateful NAT64.
 **** RFC 7757 Explicit Address Mappings for Stateless IP/ICMP Translation
 **** RFC 4443 ICMPv6 https://tools.ietf.org/html/rfc4443
+**** RFC 4861: https://tools.ietf.org/html/rfc4861 Neighbor discovery
 **** RFC 2460 IPv6 (Checksum https://tools.ietf.org/html/rfc2460#section-8.1)
 **** EAMT/Jool: https://www.jool.mx/en/eamt.html
+**** Solicited node multicast address https://en.wikipedia.org/wiki/Solicited-node_multicast_address
 * Proposal / task description
 ** Task description for mystudies
 *** High speed NAT64 with P4
diff --git a/p4app/controller.py b/p4app/controller.py
index 5a1d1a8..2bfb9c0 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -86,6 +86,21 @@ class L2Controller(object):
         # Now add global address
         subprocess.call(["mx", host, "ip", "addr", "add", ipaddr, "dev", dev])
 
+    def init_ndp(self):
+        """ initialise neighbor discovery protocol"""
+
+        all_ports = range(1,5)
+        # create multicast nodes
+        for rid in range(1,5):
+            ports = [ x for x in all_ports if not x == rid ]
+            n_handle = self.controller.mc_node_create(rid, ports)
+            log.debug("Creating MC node rid={} ports={} handle={}".format(rid, ports, n_handle))
+
+            g_handle = self.controller.mc_mgrp_create(rid)
+            log.debug("Creating MC group mgrp={} handle={} && associating afterwards".format(rid, g_handle))
+
+            self.controller.mc_node_associate(g_handle, n_handle)
+
     def init_boilerplate(self, sw_name):
         self.topo = Topology(db="topology.db")
         self.sw_name = sw_name
@@ -98,6 +113,8 @@ class L2Controller(object):
         if self.cpu_port:
             self.controller.mirroring_add(100, self.cpu_port)
 
+        self.init_ndp()
+
     def config(self):
         self.fill_tables()
         self.config_hosts()