Revision 4015e066 mininet/nodelib.py
| mininet/nodelib.py | ||
|---|---|---|
| 1 | 1 |
""" |
| 2 | 2 |
Node Library for Mininet |
| 3 | 3 |
|
| 4 |
This contains additional Node types which you may find to be useful |
|
| 4 |
This contains additional Node types which you may find to be useful.
|
|
| 5 | 5 |
""" |
| 6 | 6 |
|
| 7 |
from mininet.net import Mininet |
|
| 8 |
from mininet.topo import Topo |
|
| 9 |
from mininet.node import Switch |
|
| 7 |
from mininet.node import Node, Switch |
|
| 10 | 8 |
from mininet.log import setLogLevel, info |
| 11 | 9 |
|
| 12 |
|
|
| 13 | 10 |
class LinuxBridge( Switch ): |
| 14 | 11 |
"Linux Bridge (with optional spanning tree)" |
| 15 | 12 |
|
| ... | ... | |
| 49 | 46 |
self.cmd( 'ifconfig', self, 'down' ) |
| 50 | 47 |
self.cmd( 'brctl delbr', self ) |
| 51 | 48 |
|
| 49 |
class NAT( Node ): |
|
| 50 |
"""NAT: Provides connectivity to external network""" |
|
| 51 |
|
|
| 52 |
def __init__( self, name, inetIntf='eth0', subnet='10.0/8', localIntf=None, **params): |
|
| 53 |
super( NAT, self ).__init__( name, **params ) |
|
| 54 |
|
|
| 55 |
"""Start NAT/forwarding between Mininet and external network |
|
| 56 |
inetIntf: interface for internet access |
|
| 57 |
subnet: Mininet subnet (default 10.0/8)=""" |
|
| 58 |
self.inetIntf = inetIntf |
|
| 59 |
self.subnet = subnet |
|
| 60 |
self.localIntf = localIntf |
|
| 61 |
|
|
| 62 |
def config( self, **params ): |
|
| 63 |
super( NAT, self).config( **params ) |
|
| 64 |
"""Configure the NAT and iptables""" |
|
| 65 |
|
|
| 66 |
if not self.localIntf: |
|
| 67 |
self.localIntf = self.defaultIntf() |
|
| 68 |
|
|
| 69 |
self.cmd( 'sysctl net.ipv4.ip_forward=0' ) |
|
| 70 |
|
|
| 71 |
# Flush any currently active rules |
|
| 72 |
# TODO: is this safe? |
|
| 73 |
self.cmd( 'iptables -F' ) |
|
| 74 |
self.cmd( 'iptables -t nat -F' ) |
|
| 75 |
|
|
| 76 |
# Create default entries for unmatched traffic |
|
| 77 |
self.cmd( 'iptables -P INPUT ACCEPT' ) |
|
| 78 |
self.cmd( 'iptables -P OUTPUT ACCEPT' ) |
|
| 79 |
self.cmd( 'iptables -P FORWARD DROP' ) |
|
| 80 |
|
|
| 81 |
# Configure NAT |
|
| 82 |
self.cmd( 'iptables -I FORWARD -i', self.localIntf, '-d', self.subnet, '-j DROP' ) |
|
| 83 |
self.cmd( 'iptables -A FORWARD -i', self.localIntf, '-s', self.subnet, '-j ACCEPT' ) |
|
| 84 |
self.cmd( 'iptables -A FORWARD -i', self.inetIntf, '-d', self.subnet, '-j ACCEPT' ) |
|
| 85 |
self.cmd( 'iptables -t nat -A POSTROUTING -o ', self.inetIntf, '-j MASQUERADE' ) |
|
| 86 |
|
|
| 87 |
# Instruct the kernel to perform forwarding |
|
| 88 |
self.cmd( 'sysctl net.ipv4.ip_forward=1' ) |
|
| 89 |
|
|
| 90 |
# Prevent network-manager from messing with our interface |
|
| 91 |
# by specifying manual configuration in /etc/network/interfaces |
|
| 92 |
intf = self.localIntf |
|
| 93 |
cfile = '/etc/network/interfaces' |
|
| 94 |
line = '\niface %s inet manual\n' % intf |
|
| 95 |
config = open( cfile ).read() |
|
| 96 |
if ( line ) not in config: |
|
| 97 |
info( '*** Adding "' + line.strip() + '" to ' + cfile ) |
|
| 98 |
with open( cfile, 'a' ) as f: |
|
| 99 |
f.write( line ) |
|
| 100 |
# Probably need to restart network-manager to be safe - |
|
| 101 |
# hopefully this won't disconnect you |
|
| 102 |
self.cmd( 'service network-manager restart' ) |
|
| 103 |
|
|
| 104 |
def terminate( self ): |
|
| 105 |
"""Stop NAT/forwarding between Mininet and external network""" |
|
| 106 |
# Flush any currently active rules |
|
| 107 |
# TODO: is this safe? |
|
| 108 |
self.cmd( 'iptables -F' ) |
|
| 109 |
self.cmd( 'iptables -t nat -F' ) |
|
| 110 |
|
|
| 111 |
# Instruct the kernel to stop forwarding |
|
| 112 |
self.cmd( 'sysctl net.ipv4.ip_forward=0' ) |
|
| 113 |
|
|
| 114 |
super( NAT, self ).terminate() |
|
| 115 |
|
|
Also available in: Unified diff