147 lines
5.0 KiB
Python
147 lines
5.0 KiB
Python
"""
|
|
Node Library for Mininet
|
|
|
|
This contains additional Node types which you may find to be useful.
|
|
"""
|
|
|
|
from mininet.node import Node, Switch
|
|
from mininet.log import info, warn
|
|
from mininet.moduledeps import pathCheck
|
|
|
|
import re
|
|
|
|
class LinuxBridge( Switch ):
|
|
"Linux Bridge (with optional spanning tree)"
|
|
|
|
nextPrio = 100 # next bridge priority for spanning tree
|
|
|
|
def __init__( self, name, stp=False, prio=None, **kwargs ):
|
|
"""stp: use spanning tree protocol? (default False)
|
|
prio: optional explicit bridge priority for STP"""
|
|
self.stp = stp
|
|
if prio:
|
|
self.prio = prio
|
|
else:
|
|
self.prio = LinuxBridge.nextPrio
|
|
LinuxBridge.nextPrio += 1
|
|
Switch.__init__( self, name, **kwargs )
|
|
|
|
def connected( self ):
|
|
"Are we forwarding yet?"
|
|
if self.stp:
|
|
return 'forwarding' in self.cmd( 'brctl showstp', self )
|
|
else:
|
|
return True
|
|
|
|
def start( self, _controllers ):
|
|
"Start Linux bridge"
|
|
self.cmd( 'ifconfig', self, 'down' )
|
|
self.cmd( 'brctl delbr', self )
|
|
self.cmd( 'brctl addbr', self )
|
|
if self.stp:
|
|
self.cmd( 'brctl setbridgeprio', self.prio )
|
|
self.cmd( 'brctl stp', self, 'on' )
|
|
for i in self.intfList():
|
|
if self.name in i.name:
|
|
self.cmd( 'brctl addif', self, i )
|
|
self.cmd( 'ifconfig', self, 'up' )
|
|
|
|
def stop( self ):
|
|
"Stop Linux bridge"
|
|
self.cmd( 'ifconfig', self, 'down' )
|
|
self.cmd( 'brctl delbr', self )
|
|
|
|
def dpctl( self, *args ):
|
|
"Run brctl command"
|
|
return self.cmd( 'brctl', *args )
|
|
|
|
@classmethod
|
|
def setup( cls ):
|
|
"Make sure our class dependencies are available"
|
|
pathCheck( 'brctl', moduleName='bridge-utils' )
|
|
|
|
|
|
class NAT( Node ):
|
|
"NAT: Provides connectivity to external network"
|
|
|
|
def __init__( self, name, inetIntf=None, subnet='10.0/8',
|
|
localIntf=None, **params):
|
|
"""Start NAT/forwarding between Mininet and external network
|
|
inetIntf: interface for internet access
|
|
subnet: Mininet subnet (default 10.0/8)="""
|
|
super( NAT, self ).__init__( name, **params )
|
|
|
|
self.inetIntf = inetIntf if inetIntf else self.getGatewayIntf()
|
|
self.subnet = subnet
|
|
self.localIntf = localIntf
|
|
|
|
def config( self, **params ):
|
|
"""Configure the NAT and iptables"""
|
|
super( NAT, self).config( **params )
|
|
|
|
if not self.localIntf:
|
|
self.localIntf = self.defaultIntf()
|
|
|
|
self.cmd( 'sysctl net.ipv4.ip_forward=0' )
|
|
|
|
# Flush any currently active rules
|
|
# TODO: is this safe?
|
|
self.cmd( 'iptables -F' )
|
|
self.cmd( 'iptables -t nat -F' )
|
|
|
|
# Create default entries for unmatched traffic
|
|
self.cmd( 'iptables -P INPUT ACCEPT' )
|
|
self.cmd( 'iptables -P OUTPUT ACCEPT' )
|
|
self.cmd( 'iptables -P FORWARD DROP' )
|
|
|
|
# Configure NAT
|
|
self.cmd( 'iptables -I FORWARD',
|
|
'-i', self.localIntf, '-d', self.subnet, '-j DROP' )
|
|
self.cmd( 'iptables -A FORWARD',
|
|
'-i', self.localIntf, '-s', self.subnet, '-j ACCEPT' )
|
|
self.cmd( 'iptables -A FORWARD',
|
|
'-i', self.inetIntf, '-d', self.subnet, '-j ACCEPT' )
|
|
self.cmd( 'iptables -t nat -A POSTROUTING',
|
|
'-o', self.inetIntf, '-s', self.subnet, '-j MASQUERADE' )
|
|
|
|
# Instruct the kernel to perform forwarding
|
|
self.cmd( 'sysctl net.ipv4.ip_forward=1' )
|
|
|
|
# Prevent network-manager from messing with our interface
|
|
# by specifying manual configuration in /etc/network/interfaces
|
|
intf = self.localIntf
|
|
cfile = '/etc/network/interfaces'
|
|
line = '\niface %s inet manual\n' % intf
|
|
config = open( cfile ).read()
|
|
if ( line ) not in config:
|
|
info( '*** Adding "' + line.strip() + '" to ' + cfile + '\n' )
|
|
with open( cfile, 'a' ) as f:
|
|
f.write( line )
|
|
# Probably need to restart network-manager to be safe -
|
|
# hopefully this won't disconnect you
|
|
self.cmd( 'service network-manager restart' )
|
|
|
|
def getGatewayIntf( self, fallback='eth0' ):
|
|
"""Return gateway interface name
|
|
fallback: default device to fall back to"""
|
|
routes = self.cmd( 'ip route show' )
|
|
match = re.search( r'default via \S+ dev (\S+)', routes )
|
|
if match:
|
|
return match.group( 1 )
|
|
else:
|
|
warn( 'There is no default route set.',
|
|
'Using', fallback, 'as gateway interface...\n' )
|
|
return fallback
|
|
|
|
def terminate( self ):
|
|
"""Stop NAT/forwarding between Mininet and external network"""
|
|
# Flush any currently active rules
|
|
# TODO: is this safe?
|
|
self.cmd( 'iptables -F' )
|
|
self.cmd( 'iptables -t nat -F' )
|
|
|
|
# Instruct the kernel to stop forwarding
|
|
self.cmd( 'sysctl net.ipv4.ip_forward=0' )
|
|
|
|
super( NAT, self ).terminate()
|