mininet/mininet/node.py at patch-1 · nhminga/mininet

Repository navigation

Node objects for Mininet.
Nodes provide a simple abstraction for interacting with hosts, switches
and controllers. Local nodes are simply one or more processes on the local
Node: superclass for all (primarily local) network nodes.
Host: a virtual host. By default, a host is simply a shell; commands
    may be sent using Cmd (which waits for output), or using sendCmd(),
    which returns immediately, allowing subsequent monitoring using
    monitor(). Examples of how to run experiments using this
    functionality are provided in the examples/ directory.
CPULimitedHost: a virtual host whose CPU bandwidth is limited by
    RT or CFS bandwidth limiting.
Switch: superclass for switch nodes.
UserSwitch: a switch using the user-space switch from the OpenFlow
    reference implementation.
KernelSwitch: a switch using the kernel switch from the OpenFlow reference
    implementation.
OVSSwitch: a switch using the OpenVSwitch OpenFlow-compatible switch
    implementation (openvswitch.org).
Controller: superclass for OpenFlow controllers. The default controller
    is controller(8) from the reference implementation.
NOXController: a controller node using NOX (noxrepo.org).
RemoteController: a remote controller node, which may use any
    arbitrary OpenFlow-compatible controller, and which is not
    created or managed by mininet.
Future enhancements:
- Possibly make Node, Switch and Controller more abstract so that
  they can be used for both local and remote nodes
- Create proxy objects for remote nodes (Mininet: Cluster Edition)
import signal
import select
from subprocess import Popen, PIPE, STDOUT
from operator import or_
from time import sleep
from mininet.log import info, error, warn, debug
from mininet.util import ( quietRun, errRun, errFail, moveIntf, isShellBuiltin,
                           numCores, retry, mountCgroups )
from mininet.moduledeps import moduleDeps, pathCheck, OVS_KMOD, OF_KMOD, TUN
from mininet.link import Link, Intf, TCIntf
class Node( object ):
    """A virtual network node is simply a shell in a network namespace.
       We communicate with it using pipes."""
    portBase = 0  # Nodes always start with eth0/port0, even in OF 1.0
    def __init__( self, name, inNamespace=True, **params ):
        """name: name of node
           inNamespace: in network namespace?
           params: Node parameters (see config() for details)"""
        # Make sure class actually works
        self.checkSetup()
        self.name = name
        self.inNamespace = inNamespace
        # Stash configuration parameters for future reference
        self.params = params
        self.intfs = {}  # dict of port numbers to interfaces
        self.ports = {}  # dict of interfaces to port numbers
                         # replace with Port objects, eventually ?
        self.nameToIntf = {}  # dict of interface names to Intfs
        # Make pylint happy
        ( self.shell, self.execed, self.pid, self.stdin, self.stdout,
            self.lastPid, self.lastCmd, self.pollOut ) = (
                None, None, None, None, None, None, None, None )
        self.waiting = False
        self.readbuf = ''
        # Start command interpreter shell
        self.startShell()
    # File descriptor to node mapping support
    # Class variables and methods
    inToNode = {}  # mapping of input fds to nodes
    outToNode = {}  # mapping of output fds to nodes
    @classmethod
    def fdToNode( cls, fd ):
        """Return node corresponding to given file descriptor.
           fd: file descriptor
           returns: node"""
        node = cls.outToNode.get( fd )
        return node or cls.inToNode.get( fd )
    # Command support via shell process in namespace
    def startShell( self ):
        "Start a shell process for running commands"
        if self.shell:
            error( "%s: shell is already running" )
            return
        # mnexec: (c)lose descriptors, (d)etach from tty,
        # (p)rint pid, and run in (n)amespace
        opts = '-cdp'
        if self.inNamespace:
            opts += 'n'
        # bash -m: enable job control
        # -s: pass $* to shell, and make process easy to find in ps
        cmd = [ 'mnexec', opts, 'bash', '-ms', 'mininet:' + self.name ]
        self.shell = Popen( cmd, stdin=PIPE, stdout=PIPE, stderr=STDOUT,
                            close_fds=True )
        self.stdin = self.shell.stdin
        self.stdout = self.shell.stdout
        self.pid = self.shell.pid
        self.pollOut = select.poll()
        self.pollOut.register( self.stdout )
        # Maintain mapping between file descriptors and nodes
        # This is useful for monitoring multiple nodes
        # using select.poll()
        self.outToNode[ self.stdout.fileno() ] = self
        self.inToNode[ self.stdin.fileno() ] = self
        self.execed = False
        self.lastCmd = None
        self.lastPid = None
        self.readbuf = ''
        self.waiting = False
    def cleanup( self ):
        "Help python collect its garbage."
        # Intfs may end up in root NS
        for intfName in self.intfNames():
            if self.name in intfName:
                quietRun( 'ip link del ' + intfName )
        self.shell = None
    # Subshell I/O, commands and control
    def read( self, maxbytes=1024 ):
        """Buffered read from node, non-blocking.
           maxbytes: maximum number of bytes to return"""
        count = len( self.readbuf )
        if count < maxbytes:
            data = os.read( self.stdout.fileno(), maxbytes - count )
            self.readbuf += data
        if maxbytes >= len( self.readbuf ):
            result = self.readbuf
            self.readbuf = ''
        else:
            result = self.readbuf[ :maxbytes ]
            self.readbuf = self.readbuf[ maxbytes: ]
        return result
    def readline( self ):
        """Buffered readline from node, non-blocking.
           returns: line (minus newline) or None"""
        self.readbuf += self.read( 1024 )
        if '\n' not in self.readbuf:
            return None
        pos = self.readbuf.find( '\n' )
        line = self.readbuf[ 0: pos ]
        self.readbuf = self.readbuf[ pos + 1: ]
        return line
    def write( self, data ):
        """Write data to node.
           data: string"""
        os.write( self.stdin.fileno(), data )
    def terminate( self ):
        "Send kill signal to Node and clean up after it."
        if self.shell:
            os.killpg( self.pid, signal.SIGKILL )
        self.cleanup()
    def stop( self ):
        "Stop node."
        self.terminate()
    def waitReadable( self, timeoutms=None ):
        """Wait until node's output is readable.
           timeoutms: timeout in ms or None to wait indefinitely."""
        if len( self.readbuf ) == 0:
            self.pollOut.poll( timeoutms )
    def sendCmd( self, *args, **kwargs ):
        """Send a command, followed by a command to echo a sentinel,
           and return without waiting for the command to complete.
           args: command and arguments, or string
           printPid: print command's PID?"""
        assert not self.waiting
        printPid = kwargs.get( 'printPid', True )
        # Allow sendCmd( [ list ] )
        if len( args ) == 1 and type( args[ 0 ] ) is list:
            cmd = args[ 0 ]
        # Allow sendCmd( cmd, arg1, arg2... )
        elif len( args ) > 0:
            cmd = args
        # Convert to string
        if not isinstance( cmd, str ):
            cmd = ' '.join( [ str( c ) for c in cmd ] )
        if not re.search( r'\w', cmd ):
            # Replace empty commands with something harmless
            cmd = 'echo -n'
        self.lastCmd = cmd
        printPid = printPid and not isShellBuiltin( cmd )
        if len( cmd ) > 0 and cmd[ -1 ] == '&':
            # print ^A{pid}\n{sentinel}
            cmd += ' printf "\\001%d\n\\177" $! \n'
        else:
            # print sentinel
            cmd += '; printf "\\177"'
            if printPid and not isShellBuiltin( cmd ):
                cmd = 'mnexec -p ' + cmd
        self.write( cmd + '\n' )
        self.lastPid = None
        self.waiting = True
    def sendInt( self, sig=signal.SIGINT ):
        "Interrupt running command."
        if self.lastPid:
            try:
                os.kill( self.lastPid, sig )
            except OSError:
    def monitor( self, timeoutms=None ):
        """Monitor and return the output of a command.
           Set self.waiting to False if command has completed.
           timeoutms: timeout in ms or None to wait indefinitely."""
        self.waitReadable( timeoutms )
        data = self.read( 1024 )
        # Look for PID
        marker = chr( 1 ) + r'\d+\n'
        if chr( 1 ) in data:
            markers = re.findall( marker, data )
            if markers:
                self.lastPid = int( markers[ 0 ][ 1: ] )
                data = re.sub( marker, '', data )
        # Look for sentinel/EOF
        if len( data ) > 0 and data[ -1 ] == chr( 127 ):
            self.waiting = False
            data = data[ :-1 ]
        elif chr( 127 ) in data:
            self.waiting = False
            data = data.replace( chr( 127 ), '' )
        return data
    def waitOutput( self, verbose=False ):
        """Wait for a command to complete.
           Completion is signaled by a sentinel character, ASCII(127)
           appearing in the output stream.  Wait for the sentinel and return
           the output, including trailing newline.
           verbose: print output interactively"""
        log = info if verbose else debug
        output = ''
        while self.waiting:
            data = self.monitor()
            output += data
            log( data )
        return output
    def cmd( self, *args, **kwargs ):
        """Send a command, wait for output, and return it.
           cmd: string"""
        verbose = kwargs.get( 'verbose', False )
        log = info if verbose else debug
        log( '*** %s : %s\n' % ( self.name, args ) )
        self.sendCmd( *args, **kwargs )
        return self.waitOutput( verbose )
    def cmdPrint( self, *args):
        """Call cmd and printing its output
           cmd: string"""
        return self.cmd( *args, **{ 'verbose': True } )
    def popen( self, *args, **kwargs ):
        """Return a Popen() object in our namespace
           args: Popen() args, single list, or string
           kwargs: Popen() keyword args"""
        defaults = { 'stdout': PIPE, 'stderr': PIPE,
                     'mncmd':
                     [ 'mnexec', '-da', str( self.pid ) ] }
        defaults.update( kwargs )
        if len( args ) == 1:
            if type( args[ 0 ] ) is list:
                # popen([cmd, arg1, arg2...])
                cmd = args[ 0 ]
            elif type( args[ 0 ] ) is str:
                # popen("cmd arg1 arg2...")
                cmd = args[ 0 ].split()
            else:
                raise Exception( 'popen() requires a string or list' )
        elif len( args ) > 0:
            # popen( cmd, arg1, arg2... )
            cmd = list( args )
        # Attach to our namespace  using mnexec -a
        mncmd = defaults[ 'mncmd' ]
        del defaults[ 'mncmd' ]
        cmd = mncmd + cmd
        # Shell requires a string, not a list!
        if defaults.get( 'shell', False ):
            cmd = ' '.join( cmd )
        return Popen( cmd, **defaults )
    def pexec( self, *args, **kwargs ):
        """Execute a command using popen
           returns: out, err, exitcode"""
        popen = self.popen( *args, **kwargs)
        out, err = popen.communicate()
        exitcode = popen.wait()
        return out, err, exitcode
    # Interface management, configuration, and routing
    # BL notes: This might be a bit redundant or over-complicated.
    # However, it does allow a bit of specialization, including
    # changing the canonical interface names. It's also tricky since
    # the real interfaces are created as veth pairs, so we can't
    # make a single interface at a time.
    def newPort( self ):
        "Return the next port number to allocate."
        if len( self.ports ) > 0:
            return max( self.ports.values() ) + 1
        return self.portBase
    def addIntf( self, intf, port=None ):
        """Add an interface.
           intf: interface
           port: port number (optional, typically OpenFlow port number)"""
        if port is None:
            port = self.newPort()
        self.intfs[ port ] = intf
        self.ports[ intf ] = port
        self.nameToIntf[ intf.name ] = intf
        debug( '\n' )
        debug( 'added intf %s:%d to node %s\n' % ( intf, port, self.name ) )
        if self.inNamespace:
            debug( 'moving', intf, 'into namespace for', self.name, '\n' )
            moveIntf( intf.name, self )
    def defaultIntf( self ):
        "Return interface for lowest port"
        ports = self.intfs.keys()
        if ports:
            return self.intfs[ min( ports ) ]
        else:
            warn( '*** defaultIntf: warning:', self.name,
                  'has no interfaces\n' )
    def intf( self, intf='' ):
        """Return our interface object with given string name,
           default intf if name is falsy (None, empty string, etc).
           or the input intf arg.
        Having this fcn return its arg for Intf objects makes it
        easier to construct functions with flexible input args for
        interfaces (those that accept both string names and Intf objects).
        """
        if not intf:
            return self.defaultIntf()
        elif type( intf ) is str:
            return self.nameToIntf[ intf ]
        else:
            return intf
    def connectionsTo( self, node):
        "Return [ intf1, intf2... ] for all intfs that connect self to node."
        # We could optimize this if it is important
        connections = []
        for intf in self.intfList():
            link = intf.link
            if link:
                node1, node2 = link.intf1.node, link.intf2.node
                if node1 == self and node2 == node:
                    connections += [ ( intf, link.intf2 ) ]
                elif node1 == node and node2 == self:
                    connections += [ ( intf, link.intf1 ) ]
        return connections
    def deleteIntfs( self, checkName=True ):
        """Delete all of our interfaces.
           checkName: only delete interfaces that contain our name"""
        # In theory the interfaces should go away after we shut down.
        # However, this takes time, so we're better off removing them
        # explicitly so that we won't get errors if we run before they
        # have been removed by the kernel. Unfortunately this is very slow,
        # at least with Linux kernels before 2.6.33
        for intf in self.intfs.values():
            # Protect against deleting hardware interfaces
            if ( self.name in intf.name ) or ( not checkName ):
                intf.delete()
                info( '.' )
    # Routing support
    def setARP( self, ip, mac ):
        """Add an ARP entry.
           ip: IP address as string
           mac: MAC address as string"""
        result = self.cmd( 'arp', '-s', ip, mac )
        return result
    def setHostRoute( self, ip, intf ):
        """Add route to host.
           ip: IP address as dotted decimal
           intf: string, interface name"""
        return self.cmd( 'route add -host', ip, 'dev', intf )
    def setDefaultRoute( self, intf=None ):
        """Set the default route to go through intf.
           intf: Intf or {dev <intfname> via <gw-ip> ...}"""
        # Note setParam won't call us if intf is none
        if type( intf ) is str and ' ' in intf:
            params = intf
        else:
            params = 'dev %s' % intf
        self.cmd( 'ip route del default' )
        return self.cmd( 'ip route add default', params )
    # Convenience and configuration methods
    def setMAC( self, mac, intf=None ):
        """Set the MAC address for an interface.
           intf: intf or intf name
           mac: MAC address as string"""
        return self.intf( intf ).setMAC( mac )
    def setIP( self, ip, prefixLen=8, intf=None ):
        """Set the IP address for an interface.
           intf: intf or intf name
           ip: IP address as a string
           prefixLen: prefix length, e.g. 8 for /8 or 16M addrs"""
        # This should probably be rethought
        if '/' not in ip:
            ip = '%s/%s' % ( ip, prefixLen )
        return self.intf( intf ).setIP( ip )
    def IP( self, intf=None ):
        "Return IP address of a node or specific interface."
        return self.intf( intf ).IP()
    def MAC( self, intf=None ):
        "Return MAC address of a node or specific interface."
        return self.intf( intf ).MAC()
    def intfIsUp( self, intf=None ):
        "Check if an interface is up."
        return self.intf( intf ).isUp()
    # The reason why we configure things in this way is so
    # That the parameters can be listed and documented in
    # the config method.
    # Dealing with subclasses and superclasses is slightly
    # annoying, but at least the information is there!
    def setParam( self, results, method, **param ):
        """Internal method: configure a *single* parameter
           results: dict of results to update
           method: config method name
           param: arg=value (ignore if value=None)
           value may also be list or dict"""
        name, value = param.items()[ 0 ]
        f = getattr( self, method, None )
        if not f or value is None:
            return
        if type( value ) is list:
            result = f( *value )
        elif type( value ) is dict:
            result = f( **value )
        else:
            result = f( value )
        results[ name ] = result
        return result
    def config( self, mac=None, ip=None,
                defaultRoute=None, lo='up', **_params ):
        """Configure Node according to (optional) parameters:
           mac: MAC address for default interface
           ip: IP address for default interface
           ifconfig: arbitrary interface configuration
           Subclasses should override this method and call
           the parent class's config(**params)"""
        # If we were overriding this method, we would call
        # the superclass config method here as follows:
        # r = Parent.config( **_params )
        r = {}
        self.setParam( r, 'setMAC', mac=mac )
        self.setParam( r, 'setIP', ip=ip )
        self.setParam( r, 'setDefaultRoute', defaultRoute=defaultRoute )
        # This should be examined
        self.cmd( 'ifconfig lo ' + lo )
        return r
    def configDefault( self, **moreParams ):
        "Configure with default parameters"
        self.params.update( moreParams )
        self.config( **self.params )
    # This is here for backward compatibility
    def linkTo( self, node, link=Link ):
        """(Deprecated) Link to another node
           replace with Link( node1, node2)"""
        return link( self, node )
    # Other methods
    def intfList( self ):
        "List of our interfaces sorted by port number"
        return [ self.intfs[ p ] for p in sorted( self.intfs.iterkeys() ) ]
    def intfNames( self ):
        "The names of our interfaces sorted by port number"
        return [ str( i ) for i in self.intfList() ]
    def __repr__( self ):
        "More informative string representation"
        intfs = ( ','.join( [ '%s:%s' % ( i.name, i.IP() )
                              for i in self.intfList() ] ) )
        return '<%s %s: %s pid=%s> ' % (
            self.__class__.__name__, self.name, intfs, self.pid )
    def __str__( self ):
        "Abbreviated string representation"
        return self.name
    # Automatic class setup support
    isSetup = False
    @classmethod
    def checkSetup( cls ):
        "Make sure our class and superclasses are set up"
        while cls and not getattr( cls, 'isSetup', True ):
            cls.setup()
            cls.isSetup = True
            # Make pylint happy
            cls = getattr( type( cls ), '__base__', None )
    @classmethod
    def setup( cls ):
        "Make sure our class dependencies are available"
        pathCheck( 'mnexec', 'ifconfig', moduleName='Mininet')
class Host( Node ):
    "A host is simply a Node"
class CPULimitedHost( Host ):
    "CPU limited host"
    def __init__( self, name, sched='cfs', **kwargs ):
        Host.__init__( self, name, **kwargs )
        # Initialize class if necessary
        if not CPULimitedHost.inited:
            CPULimitedHost.init()
        # Create a cgroup and move shell into it
        self.cgroup = 'cpu,cpuacct,cpuset:/' + self.name
        errFail( 'cgcreate -g ' + self.cgroup )
        # We don't add ourselves to a cpuset because you must
        # specify the cpu and memory placement first
        errFail( 'cgclassify -g cpu,cpuacct:/%s %s' % ( self.name, self.pid ) )
        # BL: Setting the correct period/quota is tricky, particularly
        # for RT. RT allows very small quotas, but the overhead
        # seems to be high. CFS has a mininimum quota of 1 ms, but
        # still does better with larger period values.
        self.period_us = kwargs.get( 'period_us', 100000 )
        self.sched = sched
        self.rtprio = 20
    def cgroupSet( self, param, value, resource='cpu' ):
        "Set a cgroup parameter and return its value"
        cmd = 'cgset -r %s.%s=%s /%s' % (
            resource, param, value, self.name )
        quietRun( cmd )
        nvalue = int( self.cgroupGet( param, resource ) )
        if nvalue != value:
            error( '*** error: cgroupSet: %s set to %s instead of %s\n'
                   % ( param, nvalue, value ) )
        return nvalue
    def cgroupGet( self, param, resource='cpu' ):
        "Return value of cgroup parameter"
        cmd = 'cgget -r %s.%s /%s' % (
            resource, param, self.name )
        return int( quietRun( cmd ).split()[ -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 popen( self, *args, **kwargs ):
        """Return a Popen() object in node's namespace
           args: Popen() args, single list, or string
           kwargs: Popen() keyword args"""
        # Tell mnexec to execute command in our cgroup
        mncmd = [ 'mnexec', '-da', str( self.pid ),
                  '-g', self.name ]
        if self.sched == 'rt':
            mncmd += [ '-r', str( self.rtprio ) ]
        return Host.popen( self, *args, mncmd=mncmd, **kwargs )
    def cleanup( self ):
        "Clean up Node, then clean up our cgroup"
        super( CPULimitedHost, self ).cleanup()
        retry( retries=3, delaySecs=1, fn=self.cgroupDel )
    def chrt( self ):
        "Set RT scheduling priority"
        quietRun( 'chrt -p %s %s' % ( self.rtprio, self.pid ) )
        result = quietRun( 'chrt -p %s' % self.pid )
        firstline = result.split( '\n' )[ 0 ]
        lastword = firstline.split( ' ' )[ -1 ]
        if lastword != 'SCHED_RR':
            error( '*** error: could not assign SCHED_RR to %s\n' % self.name )
        return lastword
    def rtInfo( self, f ):
        "Internal method: return parameters for RT bandwidth"
        pstr, qstr = 'rt_period_us', 'rt_runtime_us'
        # RT uses wall clock time for period and quota
        quota = int( self.period_us * f * numCores() )
        return pstr, qstr, self.period_us, quota
    def cfsInfo( self, f):
        "Internal method: return parameters for CFS bandwidth"
        pstr, qstr = 'cfs_period_us', 'cfs_quota_us'
        # CFS uses wall clock time for period and CPU time for quota.
        quota = int( self.period_us * f * numCores() )
        period = self.period_us
        if f > 0 and quota < 1000:
            debug( '(cfsInfo: increasing default period) ' )
            quota = 1000
            period = int( quota / f / numCores() )
        return pstr, qstr, period, quota
    # BL comment:
    # This may not be the right API,
    # since it doesn't specify CPU bandwidth in "absolute"
    # units the way link bandwidth is specified.
    # We should use MIPS or SPECINT or something instead.
    # Alternatively, we should change from system fraction
    # to CPU seconds per second, essentially assuming that
    # all CPUs are the same.
    def setCPUFrac( self, f=-1, sched=None):
        """Set overall CPU fraction for this host
           f: CPU bandwidth limit (fraction)
           sched: 'rt' or 'cfs'
           Note 'cfs' requires CONFIG_CFS_BANDWIDTH"""
        if not f:
            return
        if not sched:
            sched = self.sched
        if sched == 'rt':
            pstr, qstr, period, quota = self.rtInfo( f )
        elif sched == 'cfs':
            pstr, qstr, period, quota = self.cfsInfo( f )
        else:
            return
        if quota < 0:
            # Reset to unlimited
            quota = -1
        # Set cgroup's period and quota
        self.cgroupSet( pstr, period )
        self.cgroupSet( qstr, quota )
        if sched == 'rt':
            # Set RT priority if necessary
            self.chrt()
        info( '(%s %d/%dus) ' % ( sched, quota, period ) )
    def setCPUs( self, cores, mems=0 ):
        "Specify (real) cores that our cgroup can run on"
        if type( cores ) is list:
            cores = ','.join( [ str( c ) for c in cores ] )
        self.cgroupSet( resource='cpuset', param='cpus',
                        value=cores )
        # Memory placement is probably not relevant, but we
        # must specify it anyway
        self.cgroupSet( resource='cpuset', param='mems',
                        value=mems)
        # We have to do this here after we've specified
        # cpus and mems
        errFail( 'cgclassify -g cpuset:/%s %s' % (
                 self.name, self.pid ) )
    def config( self, cpu=None, cores=None, **params ):
        """cpu: desired overall system CPU fraction
           cores: (real) core(s) this host can run on
           params: parameters for Node.config()"""
        r = Node.config( self, **params )
        # Was considering cpu={'cpu': cpu , 'sched': sched}, but
        # that seems redundant
        self.setParam( r, 'setCPUFrac', cpu=cpu )
        self.setParam( r, 'setCPUs', cores=cores )
        return r
    inited = False
    @classmethod
    def init( cls ):
        "Initialization for CPULimitedHost class"
        mountCgroups()
        cls.inited = True
# Some important things to note:
# The "IP" address which setIP() assigns to the switch is not
# an "IP address for the switch" in the sense of IP routing.
# Rather, it is the IP address for the control interface,
# on the control network, and it is only relevant to the
# controller. If you are running in the root namespace
# (which is the only way to run OVS at the moment), the
# control interface is the loopback interface, and you
# normally never want to change its IP address!
# In general, you NEVER want to attempt to use Linux's
# network stack (i.e. ifconfig) to "assign" an IP address or
# MAC address to a switch data port. Instead, you "assign"
# the IP and MAC addresses in the controller by specifying
# packets that you want to receive or send. The "MAC" address
# reported by ifconfig for a switch data port is essentially
# meaningless. It is important to understand this if you
# want to create a functional router using OpenFlow.
class Switch( Node ):
    """A Switch is a Node that is running (or has execed?)
       an OpenFlow switch."""
    portBase = 1  # Switches start with port 1 in OpenFlow
    dpidLen = 16  # digits in dpid passed to switch
    def __init__( self, name, dpid=None, opts='', listenPort=None, **params):
        """dpid: dpid hex string (or None to derive from name, e.g. s1 -> 1)
           opts: additional switch options
           listenPort: port to listen on for dpctl connections"""
        Node.__init__( self, name, **params )
        self.dpid = self.defaultDpid( dpid )
        self.opts = opts
        self.listenPort = listenPort
        if not self.inNamespace:
            self.controlIntf = Intf( 'lo', self, port=0 )
    def defaultDpid( self, dpid=None ):
        "Return correctly formatted dpid from dpid or switch name (s1 -> 1)"
        if dpid:
            # Remove any colons and make sure it's a good hex number
            dpid = dpid.translate( None, ':' )
            assert len( dpid ) <= self.dpidLen and int( dpid, 16 ) >= 0
        else:
            # Use hex of the first number in the switch name
            nums = re.findall( r'\d+', self.name )
            if nums:
                dpid = hex( int( nums[ 0 ] ) )[ 2: ]
            else:
                raise Exception( 'Unable to derive default datapath ID - '
                                 'please either specify a dpid or use a '
                                 'canonical switch name such as s23.' )
        return '0' * ( self.dpidLen - len( dpid ) ) + dpid
    def defaultIntf( self ):
        "Return control interface"
        if self.controlIntf:
            return self.controlIntf
        else:
            return Node.defaultIntf( self )
    def sendCmd( self, *cmd, **kwargs ):
        """Send command to Node.
           cmd: string"""
        kwargs.setdefault( 'printPid', False )
        if not self.execed:
            return Node.sendCmd( self, *cmd, **kwargs )
        else:
            error( '*** Error: %s has execed and cannot accept commands' %
                   self.name )
    def connected( self ):
        "Is the switch connected to a controller? (override this method)"
        return False and self  # satisfy pylint
    def __repr__( self ):
        "More informative string representation"
        intfs = ( ','.join( [ '%s:%s' % ( i.name, i.IP() )
                              for i in self.intfList() ] ) )
        return '<%s %s: %s pid=%s> ' % (
            self.__class__.__name__, self.name, intfs, self.pid )
class UserSwitch( Switch ):
    "User-space switch."
    dpidLen = 12
    def __init__( self, name, dpopts='--no-slicing', **kwargs ):
        """Init.
           name: name for the switch
           dpopts: additional arguments to ofdatapath (--no-slicing)"""
        Switch.__init__( self, name, **kwargs )
        pathCheck( 'ofdatapath', 'ofprotocol',
                   moduleName='the OpenFlow reference user switch' +
                              '(openflow.org)' )
        if self.listenPort:
            self.opts += ' --listen=ptcp:%i ' % self.listenPort
        self.dpopts = dpopts
    @classmethod
    def setup( cls ):
        "Ensure any dependencies are loaded; if not, try to load them."
        if not os.path.exists( '/dev/net/tun' ):
            moduleDeps( add=TUN )
    def dpctl( self, *args ):
        "Run dpctl command"
        listenAddr = None
        if not self.listenPort:
            listenAddr = 'unix:/tmp/' + self.name
        else:
            listenAddr = 'tcp:127.0.0.1:%i' % self.listenPort
        return self.cmd( 'dpctl ' + ' '.join( args ) +
                         ' ' + listenAddr )
    def connected( self ):
        "Is the switch connected to a controller?"
        return 'remote.is-connected=true' in self.dpctl( 'status' )
    @staticmethod
    def TCReapply( intf ):
        """Unfortunately user switch and Mininet are fighting
           over tc queuing disciplines. To resolve the conflict,
           we re-create the user switch's configuration, but as a
           leaf of the TCIntf-created configuration."""
        if type( intf ) is TCIntf:
            ifspeed = 10000000000 # 10 Gbps
            minspeed = ifspeed * 0.001
            res = intf.config( **intf.params )
            if res is None: # link may not have TC parameters
                return
            # Re-add qdisc, root, and default classes user switch created, but
            # with new parent, as setup by Mininet's TCIntf
            parent = res['parent']
            intf.tc( "%s qdisc add dev %s " + parent +
                     " handle 1: htb default 0xfffe" )
            intf.tc( "%s class add dev %s classid 1:0xffff parent 1: htb rate "
                     + str(ifspeed) )
            intf.tc( "%s class add dev %s classid 1:0xfffe parent 1:0xffff " +
                     "htb rate " + str(minspeed) + " ceil " + str(ifspeed) )
    def start( self, controllers ):
        """Start OpenFlow reference user datapath.
           Log to /tmp/sN-{ofd,ofp}.log.
           controllers: list of controller objects"""
        # Add controllers
        clist = ','.join( [ 'tcp:%s:%d' % ( c.IP(), c.port )
                            for c in controllers ] )
        ofdlog = '/tmp/' + self.name + '-ofd.log'
        ofplog = '/tmp/' + self.name + '-ofp.log'
        self.cmd( 'ifconfig lo up' )
        intfs = [ str( i ) for i in self.intfList() if not i.IP() ]
        self.cmd( 'ofdatapath -i ' + ','.join( intfs ) +
                  ' punix:/tmp/' + self.name + ' -d %s ' % self.dpid +
                  self.dpopts +
                  ' 1> ' + ofdlog + ' 2> ' + ofdlog + ' &' )
        self.cmd( 'ofprotocol unix:/tmp/' + self.name +
                  ' ' + clist +
                  ' --fail=closed ' + self.opts +
                  ' 1> ' + ofplog + ' 2>' + ofplog + ' &' )
        if "no-slicing" not in self.dpopts:
            # Only TCReapply if slicing is enable
            sleep(1) # Allow ofdatapath to start before re-arranging qdisc's
            for intf in self.intfList():
                if not intf.IP():
                    self.TCReapply( intf )
    def stop( self ):
        "Stop OpenFlow reference user datapath."
        self.cmd( 'kill %ofdatapath' )
        self.cmd( 'kill %ofprotocol' )
        self.deleteIntfs()
class OVSLegacyKernelSwitch( Switch ):
    """Open VSwitch legacy kernel-space switch using ovs-openflowd.
       Currently only works in the root namespace."""
    def __init__( self, name, dp=None, **kwargs ):
        """Init.
           name: name for switch
           dp: netlink id (0, 1, 2, ...)
           defaultMAC: default MAC as unsigned int; random value if None"""
        Switch.__init__( self, name, **kwargs )
        self.dp = dp if dp else self.name
        self.intf = self.dp
        if self.inNamespace:
            error( "OVSKernelSwitch currently only works"
                   " in the root namespace.\n" )
            exit( 1 )
    @classmethod
    def setup( cls ):
        "Ensure any dependencies are loaded; if not, try to load them."
        pathCheck( 'ovs-dpctl', 'ovs-openflowd',
                   moduleName='Open vSwitch (openvswitch.org)')
        moduleDeps( subtract=OF_KMOD, add=OVS_KMOD )
    def start( self, controllers ):
        "Start up kernel datapath."
        ofplog = '/tmp/' + self.name + '-ofp.log'
        quietRun( 'ifconfig lo up' )
        # Delete local datapath if it exists;
        # then create a new one monitoring the given interfaces
        self.cmd( 'ovs-dpctl del-dp ' + self.dp )
        self.cmd( 'ovs-dpctl add-dp ' + self.dp )
        intfs = [ str( i ) for i in self.intfList() if not i.IP() ]
        self.cmd( 'ovs-dpctl', 'add-if', self.dp, ' '.join( intfs ) )
        # Run protocol daemon
        clist = ','.join( [ 'tcp:%s:%d' % ( c.IP(), c.port )
                            for c in controllers ] )
        self.cmd( 'ovs-openflowd ' + self.dp +
                  ' ' + clist +
                  ' --fail=secure ' + self.opts +
                  ' --datapath-id=' + self.dpid +
                  ' 1>' + ofplog + ' 2>' + ofplog + '&' )
        self.execed = False
    def stop( self ):
        "Terminate kernel datapath."
        quietRun( 'ovs-dpctl del-dp ' + self.dp )
        self.cmd( 'kill %ovs-openflowd' )
        self.deleteIntfs()
class OVSSwitch( Switch ):
    "Open vSwitch switch. Depends on ovs-vsctl."
    def __init__( self, name, failMode='secure', datapath='kernel',
                 inband=False, **params ):
        """Init.
           name: name for switch
           failMode: controller loss behavior (secure|open)
           datapath: userspace or kernel mode (kernel|user)
           inband: use in-band control (False)"""
        Switch.__init__( self, name, **params )
        self.failMode = failMode
        self.datapath = datapath
        self.inband = inband
    @classmethod
    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 )
    @classmethod
    def batchShutdown( cls, switches ):
        "Call ovs-vsctl del-br on all OVSSwitches in a list"
        quietRun( 'ovs-vsctl ' +
                  ' -- '.join( '--if-exists del-br %s' % s
                               for s in switches if type(s) == cls ) )
    def dpctl( self, *args ):
        "Run ovs-ofctl command"
        return self.cmd( 'ovs-ofctl', args[ 0 ], self, *args[ 1: ] )
View remainder of file in raw view
FilesExpand file tree

node.py

Latest commit

History

node.py

File metadata and controls
