From 880db528e71f61e6d646bd4f0d56100355ae173e Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Tue, 19 Mar 2019 23:01:55 +0100
Subject: [PATCH] Mute multicast registrations (MLDv2)

---
 doc/plan.org            |  6 ++++--
 p4app/controller.py     | 41 +++++++++++++++++++++++++++--------------
 p4src/static-mapping.p4 |  3 ---
 3 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/doc/plan.org b/doc/plan.org
index 1074833..112aa4f 100644
--- a/doc/plan.org
+++ b/doc/plan.org
@@ -1042,8 +1042,10 @@ action:              icmp6_echo_reply
 runtime data:
 Entry has been added with handle 5
 
-
-
+***** General approach
+      - Need to react on our multicast group
+      - But also need to forward to other ports that subscribed to
+        that multicast group!
 **** Static mappings
       - likely need table(s)
       - need tcp & udp translation
diff --git a/p4app/controller.py b/p4app/controller.py
index 5ac524a..13d3d36 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -73,12 +73,15 @@ class L2Controller(object):
         self.v6_routes[None] = []
         self.v6_routes['base'] = []
 
+        self.ports = []
+
         for port in range(1,3):
             net = self.info['v6_gen'].next()
             self.v6_routes['base'].append({
                 "net": net,
                 "port": port}
             )
+            self.ports.append(port)
 
         self.v6_routes['router'] = self.v6_routes['base']
 
@@ -94,6 +97,8 @@ class L2Controller(object):
                 "net": net,
                 "port": port}
             )
+            self.ports.append(port)
+
         self.v4_routes['router'] = self.v4_routes['base']
         self.v4_routes['range_router'] = self.v4_routes['base']
 
@@ -125,6 +130,7 @@ class L2Controller(object):
                 })
 
         self.init_boilerplate(sw_name)
+        self.init_other_port_multicast_groups()
 
     def gen_ndp_multicast_addr(self, addr):
         """ append the 24 bit of the address to the multicast address"""
@@ -134,27 +140,32 @@ class L2Controller(object):
 
         return addr
 
+
+    def init_other_port_multicast_groups(self):
+        """ map multicast group x to send to
+        all ports but x - basically broadcasting without sending back to ourselves
+        """
+
+        # create multicast nodes
+        for rid in self.ports:
+            ports = [ x for x in self.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("Created MC group mgrp={} handle={} && associating afterwards".format(rid, g_handle))
+
+            self.controller.mc_node_associate(g_handle, n_handle)
+
+
     def init_ndp(self):
         """ initialise neighbor discovery protocol"""
 
         # https://en.wikipedia.org/wiki/Solicited-node_multicast_address
         ndp_prefix = "ff02::1:ff00:0/104"
 
-        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)
-
-
         self.controller.table_clear("ndp")
-        for port in all_ports:
+        for port in self.ports:
             self.controller.table_add("ndp", "multicast_pkg", [ndp_prefix, str(port)], [str(port)])
 
 
@@ -392,6 +403,8 @@ class L2Controller(object):
 
             if ICMPv6ND_NS in orig_packet and orig_packet['IPv6'].src == '::':
                 log.debug("Neighbor solicitation for checking her own IP address")
+            elif ICMPv6MLReport2 in orig_packet and orig_packet['IPv6'].dst == 'ff02::16':
+                log.debug("Multicast registration -- should probably handle this")
             elif cpu_header.task == self.task['DEBUG']:
                 log.debug("reassambled={}".format(orig_packet.__repr__()))
             elif cpu_header.task == self.task['ICMP6_NS']:
diff --git a/p4src/static-mapping.p4 b/p4src/static-mapping.p4
index d3556ef..cda8f27 100644
--- a/p4src/static-mapping.p4
+++ b/p4src/static-mapping.p4
@@ -184,7 +184,6 @@ control MyIngress(inout headers hdr,
 
     /********************** NDP support ***********************************/
 
-
     table ndp {
         key = {
             hdr.ipv6.dst_addr: lpm;
@@ -196,14 +195,12 @@ control MyIngress(inout headers hdr,
             NoAction;
         }
         size = NDP_TABLE_SIZE;
-//        default_action = NoAction;
         default_action = controller_debug;
     }
 
 
     /********************** ADDRESS TABLES ***********************************/
     action icmp6_answer() {
-
         if(hdr.icmp6.isValid()) {
             if(hdr.icmp6.code == ICMP6_ECHO_REQUEST) {
                 ipv6_addr_t tmp = hdr.ipv6.src_addr;