Bob Lantz
ee15ce2243
Although we could use print() from __future__, this messes up scripts which use examples as modules. The simple, if not nicest for 2.7, solution is to use info(), output() and other mininet.log functions. The disadvantage is that we may have to adjust things if we change info() to add automatic newlines, but we can burn that bridge in Mininet 3.x.
137 lines
4.2 KiB
Python
Executable File
137 lines
4.2 KiB
Python
Executable File
#!/usr/bin/python
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"""
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Simple example of Mobility with Mininet
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(aka enough rope to hang yourself.)
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We move a host from s1 to s2, s2 to s3, and then back to s1.
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Gotchas:
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The reference controller doesn't support mobility, so we need to
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manually flush the switch flow tables!
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Good luck!
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to-do:
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- think about wifi/hub behavior
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- think about clearing last hop - why doesn't that work?
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"""
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from mininet.net import Mininet
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from mininet.node import OVSSwitch
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from mininet.topo import LinearTopo
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from mininet.log import info, output, warn, setLogLevel
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from random import randint
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class MobilitySwitch( OVSSwitch ):
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"Switch that can reattach and rename interfaces"
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def delIntf( self, intf ):
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"Remove (and detach) an interface"
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port = self.ports[ intf ]
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del self.ports[ intf ]
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del self.intfs[ port ]
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del self.nameToIntf[ intf.name ]
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def addIntf( self, intf, rename=False, **kwargs ):
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"Add (and reparent) an interface"
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OVSSwitch.addIntf( self, intf, **kwargs )
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intf.node = self
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if rename:
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self.renameIntf( intf )
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def attach( self, intf ):
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"Attach an interface and set its port"
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port = self.ports[ intf ]
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if port:
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if self.isOldOVS():
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self.cmd( 'ovs-vsctl add-port', self, intf )
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else:
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self.cmd( 'ovs-vsctl add-port', self, intf,
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'-- set Interface', intf,
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'ofport_request=%s' % port )
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self.validatePort( intf )
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def validatePort( self, intf ):
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"Validate intf's OF port number"
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ofport = int( self.cmd( 'ovs-vsctl get Interface', intf,
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'ofport' ) )
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if ofport != self.ports[ intf ]:
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warn( 'WARNING: ofport for', intf, 'is actually', ofport,
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'\n' )
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def renameIntf( self, intf, newname='' ):
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"Rename an interface (to its canonical name)"
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intf.ifconfig( 'down' )
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if not newname:
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newname = '%s-eth%d' % ( self.name, self.ports[ intf ] )
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intf.cmd( 'ip link set', intf, 'name', newname )
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del self.nameToIntf[ intf.name ]
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intf.name = newname
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self.nameToIntf[ intf.name ] = intf
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intf.ifconfig( 'up' )
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def moveIntf( self, intf, switch, port=None, rename=True ):
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"Move one of our interfaces to another switch"
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self.detach( intf )
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self.delIntf( intf )
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switch.addIntf( intf, port=port, rename=rename )
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switch.attach( intf )
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def printConnections( switches ):
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"Compactly print connected nodes to each switch"
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for sw in switches:
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output( '%s: ' % sw )
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for intf in sw.intfList():
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link = intf.link
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if link:
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intf1, intf2 = link.intf1, link.intf2
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remote = intf1 if intf1.node != sw else intf2
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output( '%s(%s) ' % ( remote.node, sw.ports[ intf ] ) )
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output( '\n' )
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def moveHost( host, oldSwitch, newSwitch, newPort=None ):
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"Move a host from old switch to new switch"
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hintf, sintf = host.connectionsTo( oldSwitch )[ 0 ]
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oldSwitch.moveIntf( sintf, newSwitch, port=newPort )
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return hintf, sintf
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def mobilityTest():
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"A simple test of mobility"
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info( '* Simple mobility test\n' )
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net = Mininet( topo=LinearTopo( 3 ), switch=MobilitySwitch )
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info( '* Starting network:\n' )
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net.start()
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printConnections( net.switches )
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info( '* Testing network\n' )
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net.pingAll()
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info( '* Identifying switch interface for h1\n' )
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h1, old = net.get( 'h1', 's1' )
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for s in 2, 3, 1:
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new = net[ 's%d' % s ]
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port = randint( 10, 20 )
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info( '* Moving', h1, 'from', old, 'to', new, 'port', port, '\n' )
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hintf, sintf = moveHost( h1, old, new, newPort=port )
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info( '*', hintf, 'is now connected to', sintf, '\n' )
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info( '* Clearing out old flows\n' )
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for sw in net.switches:
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sw.dpctl( 'del-flows' )
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info( '* New network:\n' )
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printConnections( net.switches )
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info( '* Testing connectivity:\n' )
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net.pingAll()
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old = new
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net.stop()
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if __name__ == '__main__':
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setLogLevel( 'info' )
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mobilityTest()
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