From fbadfddee8a9734af6023dd9010e1ffebf7e9b71 Mon Sep 17 00:00:00 2001
From: Nico Schottelius <nico@nico-notebook.schottelius.org>
Date: Mon, 4 Mar 2019 14:48:15 +0100
Subject: [PATCH] [icmp6] add dedicated multicast address listener

---
 p4app/controller.py | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/p4app/controller.py b/p4app/controller.py
index da961fa..12cdb20 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -9,6 +9,7 @@ from p4utils.utils.sswitch_API import SimpleSwitchAPI
 from scapy.all import sniff, get_if_list, Ether, get_if_hwaddr, sendp
 from scapy.all import IP, Raw, IPv6, TCP, TCP_client
 from scapy.all import Ether, sniff, Packet, BitField
+from scapy.all import ICMPv6ND_NS, ICMPv6
 
 import sys
 import re
@@ -17,7 +18,6 @@ import logging
 import argparse
 import subprocess
 
-# Broken in python2
 import ipaddress
 
 logging.basicConfig()
@@ -84,6 +84,10 @@ class L2Controller(object):
         log.debug("host: {}".format(host))
         return "{}1/{}".format(net, mask)
 
+    def gen_ndp_multicast_addr(self, addr):
+        """ append the 24 bit of the address to the multicast address"""
+        return ipaddress.ip_address(int(self.info['ndp_multicast']) + (int(addr) & 0xffffff))
+
     @staticmethod
     def add_host_ips(host, net, ipaddr, dev):
         subprocess.call(["mx", host, "ip", "addr", "flush", "dev", dev])
@@ -142,6 +146,11 @@ class L2Controller(object):
         self.fill_tables()
         self.config_hosts()
 
+    def listen_to_icmp6_multicast(self):
+        """Only needed for debugging"""
+
+        net = str(self.info['ndp_multicast'])
+        self.controller.table_add("v6_networks", "controller_debug", [net])
 
     def fill_tables(self):
         self.controller.table_clear("v6_networks")
@@ -149,9 +158,8 @@ class L2Controller(object):
             net = self.prefix_to_net(v6route['net'], self.v6_mask)
             self.controller.table_add("v6_networks", "set_egress_port", [net], [v6route['port']])
 
-        net = str(self.info['ndp_multicast'])
-        self.controller.table_add("v6_networks", "controller_reply", [net])
-
+        if
+        self.listen_to_icmp6_multicast()
 
         self.controller.table_clear("v4_routing")
         for v4route in self.v4_routes[self.mode]:
@@ -160,13 +168,12 @@ class L2Controller(object):
 
         self.controller.table_clear("v6_addresses")
         for v6addr in self.v6_addresses[self.mode]:
+            icmp6_addr = str(self.gen_ndp_multicast_addr(v6addr))
+
             self.controller.table_add("v6_addresses", "controller_reply", [v6addr['addr']])
+            self.controller.table_add("v6_addresses", "controller_reply", [icmp6_addr])
 
 
-    def gen_ndp_multicast_addr(self, addr):
-        """ append the 24 bit of the address to the multicast address"""
-        return ipaddress.ip_address(int(self.info['ndp_multicast']) + (int(addr) & 0xffffff))
-
     def config_hosts(self):
         """ Assumptions:
         - all routes are networks (no /128 v6 or /32 v4
@@ -234,8 +241,10 @@ class L2Controller(object):
             print("Special handling needed")
             pass
         elif packet.type == 0x2323:
-            print("Debug pkg")
-            pass
+            # Set back (incorrectly maybe) to IPv6
+            packet.type = 0x86dd
+            print("Debug pkg: ".format(packet))
+
         else:
             print("Broken pkg: {}".format(pkg.__repr__()))
             return
@@ -250,7 +259,7 @@ class L2Controller(object):
 
         self.args = parser.parse_args()
         self.mode = self.args.mode
-
+        self.debug = args.debug
 
 if __name__ == "__main__":
     import sys