Files
mininet/mininet/link.py
T

317 lines
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Python

"""
link.py: interface and link abstractions for mininet
It seems useful to bundle functionality for interfaces into a single
class.
Also it seems useful to enable the possibility of multiple flavors of
links, including:
- simple veth pairs
- tunneled links
- patchable links (which can be disconnected and reconnected via a patchbay)
- link simulators (e.g. wireless)
Basic division of labor:
Nodes: know how to execute commands
Intfs: know how to configure themselves
Links: know how to connect nodes together
Intf: basic interface object that can configure itself
TCIntf: interface with bandwidth limiting and delay via tc
Link: basic link class for creating veth pairs
"""
from mininet.log import info, error, debug
from mininet.util import makeIntfPair
from time import sleep
import re
class Intf( object ):
"Basic interface object that can configure itself."
def __init__( self, name, node=None, link=None, **kwargs ):
"""name: interface name (e.g. h1-eth0)
node: owning node (where this intf most likely lives)
link: parent link if we're part of a link
other arguments are passed to config()"""
self.node = node
self.name = name
self.link = link
self.mac, self.ip = None, None
# Add to node (and move ourselves if necessary )
node.addIntf( self )
self.config( **kwargs )
def cmd( self, *args, **kwargs ):
return self.node.cmd( *args, **kwargs )
def ifconfig( self, *args ):
"Configure ourselves using ifconfig"
return self.cmd( 'ifconfig', self.name, *args )
def setIP( self, ipstr ):
"""Set our IP address"""
# This is a sign that we should perhaps rethink our prefix
# mechanism
self.ip, self.prefixLen = ipstr.split( '/' )
return self.ifconfig( ipstr, 'up' )
def setMAC( self, macstr ):
"""Set the MAC address for an interface.
macstr: MAC address as string"""
self.mac = macstr
return ( self.ifconfig( 'down' ) +
self.ifconfig( 'hw', 'ether', macstr ) +
self.ifconfig( 'up' ) )
_ipMatchRegex = re.compile( r'\d+\.\d+\.\d+\.\d+' )
_macMatchRegex = re.compile( r'..:..:..:..:..:..' )
def updateIP( self ):
"Return updated IP address based on ifconfig"
ifconfig = self.ifconfig()
ips = self._ipMatchRegex.findall( ifconfig )
self.ip = ips[ 0 ] if ips else None
return self.ip
def updateMAC( self, intf ):
"Return updated MAC address based on ifconfig"
ifconfig = self.ifconfig()
macs = self._macMatchRegex.findall( ifconfig )
self.mac = macs[ 0 ] if macs else None
return self.mac
def IP( self ):
"Return IP address"
return self.ip
def MAC( self ):
"Return MAC address"
return self.mac
def isUp( self, set=False ):
"Return whether interface is up"
if set:
self.ifconfig( 'up' )
return "UP" in self.ifconfig()
# 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, ifconfig=None,
defaultRoute=None, up=True, **params):
"""Configure Node according to (optional) parameters:
mac: MAC address
ip: IP address
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, 'isUp', up=up )
self.setParam( r, 'ifconfig', ifconfig=ifconfig )
return r
def delete( self ):
"Delete interface"
self.cmd( 'ip link del ' + self.name )
# Does it help to sleep to let things run?
sleep( 0.001 )
def __str__( self ):
return self.name
class TCIntf( Intf ):
"Interface customized by tc (traffic control) utility"
def config( self, bw=None, delay=None, loss=None, disable_gro=True,
speedup=0, use_hfsc=False, use_tbf=False, enable_ecn=False,
enable_red=False, max_queue_size=None, **params ):
"Configure the port and set its properties."
result = Intf.config( self, **params)
# disable GRO
if disable_gro:
self.cmd( 'ethtool -K %s gro off' % self )
if ( bw is None and not delay and not loss
and max_queue_size is None ):
return
if bw and ( bw < 0 or bw > 1000 ):
error( 'Bandwidth', bw, 'is outside range 0..1000 Mbps\n' )
return
if delay and delay < 0:
error( 'Negative delay', delay, '\n' )
return
if loss and ( loss < 0 or loss > 100 ):
error( 'Bad loss percentage', loss, '%%\n' )
return
# Ugly but functional
stuff = ( ( [ '%.2fMbit' % bw ] if bw is not None else [] ) +
( [ '%s delay' % delay ] if delay is not None else [] ) +
( ['%d%% loss' % loss ] if loss is not None else [] ) +
( [ 'ECN' ] if enable_ecn else [ 'RED' ] if enable_red else [] ) )
info( '(' + ' '.join( stuff ) + ') ' )
cmds = [ '%s qdisc del dev %s root' ]
tc = 'tc' # was getCmd( 'tc' )
# Bandwidth control algorithms
if bw is None:
parent = ' root '
else:
parent = ' parent 1:1 '
# BL: hmm... this seems a bit brittle
if speedup > 0 and self.node.name[0:2] == 'sw':
bw = speedup
if use_hfsc:
cmds += [ '%s qdisc add dev %s root handle 1:0 hfsc default 1',
'%s class add dev %s parent 1:0 classid 1:1 hfsc sc ' +
'rate %fMbit ul rate %fMbit' % ( bw, bw ) ]
elif use_tbf:
latency_us = 10 * 1500 * 8 / bw
cmds += ['%s qdisc add dev %s root handle 1: tbf ' +
'rate %fMbit burst 15000 latency %fus' % (bw, latency_us) ]
else:
cmds += [ '%s qdisc add dev %s root handle 1:0 htb default 1',
'%s class add dev %s parent 1:0 classid 1:1 htb ' +
'rate %fMbit burst 15k' % bw ]
parent = ' parent 1:1 '
# ECN or RED
if enable_ecn:
cmds += [ '%s qdisc add dev %s' + parent +
'handle 10: red limit 1000000 '+
'min 20000 max 25000 avpkt 1000 '+
'burst 20 '+
'bandwidth %fmbit probability 1 ecn' % bw ]
parent = ' parent 10: '
elif enable_red:
cmds += [ '%s qdisc add dev %s' + parent +
'handle 10: red limit 1000000 '+
'min 20000 max 25000 avpkt 1000 '+
'burst 20 '+
'bandwidth %fmbit probability 1' % bw ]
parent = ' parent 10: '
# Delay/loss/max queue size
netemargs = '%s%s%s' % (
'delay %s ' % delay if delay is not None else '',
'loss %d ' % loss if loss is not None else '',
'limit %d' % max_queue_size if max_queue_size is not None else '' )
if netemargs:
cmds += [ '%s qdisc add dev %s ' + parent + ' netem ' +
netemargs ]
# Execute all the commands in the container
debug("at map stage w/cmds: %s\n" % cmds)
def doConfigPort(s):
c = s % (tc, self)
debug(" *** executing command: %s\n" % c)
return self.cmd(c)
tcoutputs = [ doConfigPort(cmd) for cmd in cmds ]
debug( "cmds:", cmds, '\n' )
debug( "outputs:", tcoutputs, '\n' )
result[ 'tcoutputs'] = tcoutputs
return result
class Link( object ):
"""A basic link is just a veth pair.
Other types of links could be tunnels, link emulators, etc.."""
def __init__( self, node1, node2, port1=None, port2=None, intfName1=None, intfName2=None,
intf=Intf, cls1=None, cls2=None, params1={}, params2={} ):
"""Create veth link to another node, making two new interfaces.
node1: first node
node2: second node
port1: node1 port number (optional)
port2: node2 port number (optional)
intf: default interface class/constructor
cls1, cls2: optional interface-specific constructors
intfName1: node1 interface name (optional)
intfName2: node2 interface name (optional)
params1: parameters for interface 1
params2: parameters for interface 2"""
# This is a bit awkward; it seems that having everything in
# params would be more orthogonal, but being able to specify
# in-line arguments is more convenient!
if port1 is None:
port1 = node1.newPort()
if port2 is None:
port2 = node2.newPort()
if not intfName1:
intfName1 = self.intfName( node1, port1 )
if not intfName2:
intfName2 = self.intfName( node2, port2 )
self.makeIntfPair( intfName1, intfName2 )
if not cls1:
cls1 = intf
if not cls2:
cls2 = intf
intf1 = cls1( name=intfName1, node=node1, link=self, **params1 )
intf2 = cls2( name=intfName2, node=node2, link=self, **params2 )
# All we are is dust in the wind, and our two interfaces
self.intf1, self.intf2 = intf1, intf2
@classmethod
def intfName( cls, node, n ):
"Construct a canonical interface name node-ethN for interface n."
return node.name + '-eth' + repr( n )
@classmethod
def makeIntfPair( cls, intf1, intf2 ):
"""Create pair of interfaces
intf1: name of interface 1
intf2: name of interface 2
(override this class method [and possibly delete()] to change link type)"""
makeIntfPair( intf1, intf2 )
def delete( self ):
"Delete this link"
self.intf1.delete()
self.intf2.delete()
def __str__( self ):
return '%s<->%s' % ( self.intf1, self.intf2 )