Files
mininet/examples/sshd.py
T
2016-06-21 16:27:04 -07:00

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#!/usr/bin/python
"""
Create a network and start sshd(8) on each host.
While something like rshd(8) would be lighter and faster,
(and perfectly adequate on an in-machine network)
the advantage of running sshd is that scripts can work
unchanged on mininet and hardware.
In addition to providing ssh access to hosts, this example
demonstrates:
- creating a convenience function to construct networks
- connecting the host network to the root namespace
- running server processes (sshd in this case) on hosts
"""
from __future__ import print_function
import sys
from mininet.net import Mininet
from mininet.cli import CLI
from mininet.log import lg
from mininet.node import Node
from mininet.topolib import TreeTopo
from mininet.util import waitListening
def TreeNet( depth=1, fanout=2, **kwargs ):
"Convenience function for creating tree networks."
topo = TreeTopo( depth, fanout )
return Mininet( topo, **kwargs )
def connectToRootNS( network, switch, ip, routes ):
"""Connect hosts to root namespace via switch. Starts network.
network: Mininet() network object
switch: switch to connect to root namespace
ip: IP address for root namespace node
routes: host networks to route to"""
# Create a node in root namespace and link to switch 0
root = Node( 'root', inNamespace=False )
intf = network.addLink( root, switch ).intf1
root.setIP( ip, intf=intf )
# Start network that now includes link to root namespace
network.start()
# Add routes from root ns to hosts
for route in routes:
root.cmd( 'route add -net ' + route + ' dev ' + str( intf ) )
def sshd( network, cmd='/usr/sbin/sshd', opts='-D',
ip='10.123.123.1/32', routes=None, switch=None ):
"""Start a network, connect it to root ns, and run sshd on all hosts.
ip: root-eth0 IP address in root namespace (10.123.123.1/32)
routes: Mininet host networks to route to (10.0/24)
switch: Mininet switch to connect to root namespace (s1)"""
if not switch:
switch = network[ 's1' ] # switch to use
if not routes:
routes = [ '10.0.0.0/24' ]
connectToRootNS( network, switch, ip, routes )
for host in network.hosts:
host.cmd( cmd + ' ' + opts + '&' )
print( "*** Waiting for ssh daemons to start" )
for server in network.hosts:
waitListening( server=server, port=22, timeout=5 )
print()
print( "*** Hosts are running sshd at the following addresses:" )
print()
for host in network.hosts:
print( host.name, host.IP() )
print()
print( "*** Type 'exit' or control-D to shut down network" )
CLI( network )
for host in network.hosts:
host.cmd( 'kill %' + cmd )
network.stop()
if __name__ == '__main__':
lg.setLogLevel( 'info')
net = TreeNet( depth=1, fanout=4 )
# get sshd args from the command line or use default args
# useDNS=no -u0 to avoid reverse DNS lookup timeout
argvopts = ' '.join( sys.argv[ 1: ] ) if len( sys.argv ) > 1 else (
'-D -o UseDNS=no -u0' )
sshd( net, opts=argvopts )