from __future__ import unicode_literals
import nnpy
import struct
from p4utils.utils.topology import Topology
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
import sys
import re
import logging
import argparse
import subprocess
import ipaddress
logging.basicConfig()
log = logging.getLogger("main")
class CpuHeader(Packet):
name = 'CpuPacket'
fields_desc = [
BitField('task',0,8)
BitField('ingress_port', 0, 16)
]
class L2Controller(object):
def __init__(self, sw_name):
# 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")
self.info['v6_mask'] = 64
self.info['v6_base'] = ipaddress.ip_network("2001:db8::/32")
self.info['v6_gen'] = self.info['v6_base'].subnets(new_prefix=self.info['v6_mask'])
self.info['v4_mask'] = 24
self.info['v4_base'] = ipaddress.ip_network("10.0.0.0/8")
self.info['v4_gen'] = self.info['v4_base'].subnets(new_prefix=self.info['v4_mask'])
self.info['switch_suffix'] = 42
self.v6_routes = {}
self.v6_routes[None] = []
self.v6_routes['base'] = []
for port in range(1,3):
net = self.info['v6_gen'].next()
self.v6_routes['base'].append({
"net": net,
"port": port}
)
self.v6_routes['router'] = self.v6_routes['base']
self.v4_routes = {}
self.v4_routes[None] = []
self.v4_routes['base'] = []
for port in range(3,5):
net = self.info['v4_gen'].next()
self.v4_routes['base'].append({
"net": net,
"port": port}
)
self.v4_routes['router'] = self.v4_routes['base']
self.v6_addresses = {}
self.v6_addresses[None] = []
self.v6_addresses['base'] = []
self.v6_addresses['router'] = [ net['net'][42] for net in self.v6_routes['router'] ]
self.v4_addresses = {}
self.v4_addresses[None] = []
self.v4_addresses['base'] = []
self.v4_addresses['router'] = [ net['net'][42] for net in self.v4_routes['router'] ]
self.init_boilerplate(sw_name)
def gen_ndp_multicast_addr(self, addr):
""" append the 24 bit of the address to the multicast address"""
last_24 = int(addr) & 0xffffff
addr = self.info['ndp_multicast'][last_24]
return addr
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:
self.controller.table_add("ndp", "multicast_pkg", [ndp_prefix, str(port)], [str(port)])
# Special rule for switch entries
self.controller.table_add("ndp_answer", "icmp6_neighbor_solicitation", ["ff02::1:ff00:42", "135"], ["2001:db8:61::42"])
def init_boilerplate(self, sw_name):
self.topo = Topology(db="topology.db")
self.sw_name = sw_name
self.thrift_port = self.topo.get_thrift_port(sw_name)
self.cpu_port = self.topo.get_cpu_port_index(self.sw_name)
self.controller = SimpleSwitchAPI(self.thrift_port)
self.intf = str(self.topo.get_cpu_port_intf(self.sw_name).replace("eth0", "eth1"))
self.controller.reset_state()
if self.cpu_port:
self.controller.mirroring_add(100, self.cpu_port)
# self.init_ndp()
def config(self):
self.fill_tables()
self.config_hosts()
def listen_to_icmp6_multicast(self):
"""Only needed for debugging"""
net = self.info['ndp_multicast']
self.controller.table_add("v6_networks", "controller_debug", [str(net)])
def fill_tables(self):
self.controller.table_clear("v6_networks")
for v6route in self.v6_routes[self.mode]:
self.controller.table_add("v6_networks", "set_egress_port", [str(v6route['net'])], [str(v6route['port'])])
self.listen_to_icmp6_multicast()
self.controller.table_clear("v4_routing")
for v4route in self.v4_routes[self.mode]:
self.controller.table_add("v4_networks", "set_egress_port", [str(v4route['net'])], [str(v4route['port'])])
self.controller.table_clear("v6_addresses")
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(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:
- all routes are networks (no /128 v6 or /32 v4
- hosts get the first ip address in the network
"""
for v6route in self.v6_routes[self.mode]:
host = "h{}".format(v6route['port'])
dev = "{}-eth0".format(host)
net = v6route['net']
ipaddr = "{}/{}".format(net[1],net.prefixlen)
self.add_host_ips(host, str(net), str(ipaddr), dev)
@staticmethod
def add_host_ips(host, net, ipaddr, dev):
log.debug("Config host: {} {}->{} on {}".format(host, net, ipaddr, dev))
subprocess.call(["mx", host, "ip", "addr", "flush", "dev", dev])
for v6dev in [ "lo", "default", "all", dev ]:
subprocess.call(["mx", host, "sysctl", "net.ipv6.conf.{}.disable_ipv6=0".format(v6dev)])
# Set down & up to regain link local address
subprocess.call(["mx", host, "ip", "link", "set", dev, "down"])
subprocess.call(["mx", host, "ip", "link", "set", dev, "up"])
# Now add global address
subprocess.call(["mx", host, "ip", "addr", "add", ipaddr, "dev", dev])
def debug_print_pkg(self, pkg, msg="INCOMING"):
log.debug("{}: {}".format(msg, pkg.__repr__()))
def debug_format_pkg(self, pkg):
packet = Ether(str(pkg))
if packet.type == 0x800:
ip = pkg.getlayer(IP)
elif packet.type == 0x86dd:
ip = pkg.getlayer(IPv6)
# tcp = pkg.getlayer(TCP)
# raw = pkg.getlayer(Raw)
# return "{}:{} => {}:{}: flags={} seq={} ack={} raw={}".format(
# ip.src, tcp.sport,
# ip.dst, tcp.dport,
# tcp.flags,
# tcp.seq,
# tcp.ack,
# raw)
def recv_msg_cpu(self, pkg):
packet = Ether(str(pkg))
self.debug_print_pkg(pkg)
if packet.type == 0x0800:
pass
elif packet.type == 0x86dd:
pass
elif packet.type == 0x4242:
print("Special handling needed")
pass
elif packet.type == 0x2323:
# Set back (incorrectly maybe) to IPv6
packet.type = 0x86dd
print("Debug pkg: ".format(packet))
else:
print("Broken pkg: {}".format(pkg.__repr__()))
return
def run_cpu_port_loop(self):
sniff(iface=self.intf, prn=self.recv_msg_cpu)
def commandline(self):
parser = argparse.ArgumentParser(description='controller++')
parser.add_argument('--mode', help='Select mode / settings to use', choices=self.modes)
parser.add_argument('--debug', help='Enable debug logging', action='store_true')
self.args = parser.parse_args()
self.mode = self.args.mode
self.debug = self.args.debug
if __name__ == "__main__":
import sys
import os
if "DEBUG" in os.environ:
log.setLevel(logging.DEBUG)
else:
log.setLevel(logging.INFO)
log.info("Booting...")
log.debug("Debug enabled.")
sw_name = "s1"
controller = L2Controller(sw_name)
controller.commandline()
if controller.args.debug:
log.setLevel(logging.DEBUG)
controller.config()
controller.run_cpu_port_loop()