def __init__( self, *args, **kwargs ):
     """servers: a list of servers to use (note: include
        localhost or None to use local system as well)
        user: user name for server ssh
        placement: Placer() subclass"""
     params = { 'host': RemoteHost,
                'switch': RemoteOVSSwitch,
                'link': RemoteLink,
                'precheck': True }
     params.update( kwargs )
     servers = params.pop( 'servers', [ 'localhost' ] )
     servers = [ s if s else 'localhost' for s in servers ]
     self.servers = servers
     self.serverIP = params.pop( 'serverIP', {} )
     if not self.serverIP:
         self.serverIP = { server: RemoteMixin.findServerIP( server )
                           for server in self.servers }
     self.user = params.pop( 'user', findUser() )
     if params.pop( 'precheck' ):
         self.precheck()
     self.connections = {}
     self.placement = params.pop( 'placement', SwitchBinPlacer )
     # Make sure control directory exists
     self.cdir = os.environ[ 'HOME' ] + '/.ssh/mn'
     errRun( [ 'mkdir', '-p', self.cdir ] )
     Mininet.__init__( self, *args, **params )

 def precheck( self ):
     """Pre-check to make sure connection works and that
        we can call sudo without a password"""
     result = 0
     info( '*** Checking servers\n' )
     for server in self.servers:
         ip = self.serverIP[ server ]
         if not server or server == 'localhost':
             continue
         info( server, '' )
         dest = '%[email protected]%s' % ( self.user, ip )
         cmd = [ 'sudo', '-E', '-u', self.user ]
         cmd += self.sshcmd + [ '-n', dest, 'sudo true' ]
         debug( ' '.join( cmd ), '\n' )
         _out, _err, code = errRun( cmd )
         if code != 0:
             error( '\nstartConnection: server connection check failed '
                    'to %s using command:\n%s\n'
                     % ( server, ' '.join( cmd ) ) )
         result |= code
     if result:
         error( '*** Server precheck failed.\n'
                '*** Make sure that the above ssh command works'
                ' correctly.\n'
                '*** You may also need to run mn -c on all nodes, and/or\n'
                '*** use sudo -E.\n' )
         sys.exit( 1 )
     info( '\n' )

 def cmd( self, *args, **kwargs ):
     "Run a command in our owning node or in root namespace when not yet inRightNamespace"
     if self.inRightNamespace:
         return self.node.cmd( *args, **kwargs )
     else:
         cmd = ' '.join( [ str( c ) for c in args ] )
         return errRun( cmd )[ 0 ]

def serviceCheck( *args, **kwargs ):
    "Make sure each service in *args can be found in /etc/init.d/."
    moduleName = kwargs.get( 'moduleName', 'it' )
    for arg in args:
        _, _, ret = errRun( 'test -x /etc/init.d/' + arg )
        if ret != 0:
            error( 'Cannot find required service %s in /etc/init.d/.\n' % arg +
                   'Please make sure that %s is installed ' % moduleName )
            exit( 1 )

 def setup( cls ):
     "Make sure IVS is installed"
     pathCheck( 'ivs-ctl', 'ivs',
                moduleName="Indigo Virtual Switch (projectfloodlight.org)" )
     out, err, exitcode = errRun( 'ivs-ctl show' )
     if exitcode:
         error( out + err +
                'ivs-ctl exited with code %d\n' % exitcode +
                '*** The openvswitch kernel module might '
                'not be loaded. Try modprobe openvswitch.\n' )
         exit( 1 )

 def checkListening(self):
     "Make sure no controllers are running on our port"
     # Verify that Telnet is installed first:
     out, _err, returnCode = errRun("which telnet")
     if "telnet" not in out or returnCode != 0:
         raise Exception(
             "Error running telnet to check for listening " "controllers; please check that it is " "installed."
         )
     listening = self.cmd("echo A | telnet -e A %s %d" % (self.ip, self.port))
     if "Unable" not in listening:
         servers = self.cmd("netstat -atp").split("\n")
         pstr = ":%d " % self.port
         clist = servers[0:1] + [s for s in servers if pstr in s]
         raise Exception(
             "Please shut down the controller which is" " running on port %d:\n" % self.port + "\n".join(clist)
         )

def unmountAll( rootdir=MNRUNDIR ):
    "Unmount all mounts under a directory tree"
    rootdir = realpath( rootdir )
    # Find all mounts below rootdir
    # This is subtle because /foo is not
    # a parent of /foot
    dirslash = rootdir + '/'
    mounts = [ m for m in mountPoints()
              if m == dir or m.find( dirslash ) == 0 ]
    # Unmount them from bottom to top
    mounts.sort( reverse=True )
    for mount in mounts:
        debug( 'Unmounting', mount, '\n' )
        _out, err, code = errRun( 'umount', mount )
        if code != 0:
            info( '*** Warning: failed to umount', mount, '\n' )
            info( err )

 def setup( cls ):
     "Make sure Open vSwitch is installed and working"
     pathCheck( 'ovs-vsctl',
                moduleName='Open vSwitch (openvswitch.org)')
     # This should no longer be needed, and it breaks
     # with OVS 1.7 which has renamed the kernel module:
     #  moduleDeps( subtract=OF_KMOD, add=OVS_KMOD )
     out, err, exitcode = errRun( 'ovs-vsctl -t 1 show' )
     if exitcode:
         error( out + err +
                'ovs-vsctl exited with code %d\n' % exitcode +
                '*** Error connecting to ovs-db with ovs-vsctl\n'
                'Make sure that Open vSwitch is installed, '
                'that ovsdb-server is running, and that\n'
                '"ovs-vsctl show" works correctly.\n'
                'You may wish to try '
                '"service openvswitch-switch start".\n' )
         exit( 1 )

 def cgroupDel( self ):
     "Clean up our cgroup"
     # info( '*** deleting cgroup', self.cgroup, '\n' )
     _out, _err, exitcode = errRun( 'cgdelete -r ' + self.cgroup )
     return exitcode != 0

def cleanUpScreens():
    "Remove moldy socat X11 tunnels."
    errRun( "pkill -9 -f mnexec.*socat" )