Statistics
| Branch: | Tag: | Revision:

mininet / mininet / link.py @ 0b7c277e

History | View | Annotate | Download (13.8 KB)

1
"""
2
link.py: interface and link abstractions for mininet
3

4
It seems useful to bundle functionality for interfaces into a single
5
class.
6

7
Also it seems useful to enable the possibility of multiple flavors of
8
links, including:
9

10
- simple veth pairs
11
- tunneled links
12
- patchable links (which can be disconnected and reconnected via a patchbay)
13
- link simulators (e.g. wireless)
14

15
Basic division of labor:
16

17
  Nodes: know how to execute commands
18
  Intfs: know how to configure themselves
19
  Links: know how to connect nodes together
20

21
Intf: basic interface object that can configure itself
22
TCIntf: interface with bandwidth limiting and delay via tc
23

24
Link: basic link class for creating veth pairs
25
"""
26

    
27
from mininet.log import info, error, debug
28
from mininet.util import makeIntfPair
29
from time import sleep
30
import re
31

    
32
class Intf( object ):
33

    
34
    "Basic interface object that can configure itself."
35

    
36
    def __init__( self, name, node=None, port=None, link=None, **params ):
37
        """name: interface name (e.g. h1-eth0)
38
           node: owning node (where this intf most likely lives)
39
           link: parent link if we're part of a link
40
           other arguments are passed to config()"""
41
        self.node = node
42
        self.name = name
43
        self.link = link
44
        self.mac, self.ip, self.prefixLen = None, None, None
45
        # Add to node (and move ourselves if necessary )
46
        node.addIntf( self, port=port )
47
        # Save params for future reference
48
        self.params = params
49
        self.config( **params )
50

    
51
    def cmd( self, *args, **kwargs ):
52
        "Run a command in our owning node"
53
        return self.node.cmd( *args, **kwargs )
54

    
55
    def ifconfig( self, *args ):
56
        "Configure ourselves using ifconfig"
57
        return self.cmd( 'ifconfig', self.name, *args )
58

    
59
    def setIP( self, ipstr, prefixLen=None ):
60
        """Set our IP address"""
61
        # This is a sign that we should perhaps rethink our prefix
62
        # mechanism and/or the way we specify IP addresses
63
        if '/' in ipstr:
64
            self.ip, self.prefixLen = ipstr.split( '/' )
65
            return self.ifconfig( ipstr, 'up' )
66
        else:
67
            self.ip, self.prefixLen = ipstr, prefixLen
68
            return self.ifconfig( '%s/%s' % ( ipstr, prefixLen ) )
69

    
70
    def setMAC( self, macstr ):
71
        """Set the MAC address for an interface.
72
           macstr: MAC address as string"""
73
        self.mac = macstr
74
        return ( self.ifconfig( 'down' ) +
75
                 self.ifconfig( 'hw', 'ether', macstr ) +
76
                 self.ifconfig( 'up' ) )
77

    
78
    _ipMatchRegex = re.compile( r'\d+\.\d+\.\d+\.\d+' )
79
    _macMatchRegex = re.compile( r'..:..:..:..:..:..' )
80

    
81
    def updateIP( self ):
82
        "Return updated IP address based on ifconfig"
83
        ifconfig = self.ifconfig()
84
        ips = self._ipMatchRegex.findall( ifconfig )
85
        self.ip = ips[ 0 ] if ips else None
86
        return self.ip
87

    
88
    def updateMAC( self ):
89
        "Return updated MAC address based on ifconfig"
90
        ifconfig = self.ifconfig()
91
        macs = self._macMatchRegex.findall( ifconfig )
92
        self.mac = macs[ 0 ] if macs else None
93
        return self.mac
94

    
95
    def IP( self ):
96
        "Return IP address"
97
        return self.ip
98

    
99
    def MAC( self ):
100
        "Return MAC address"
101
        return self.mac
102

    
103
    def isUp( self, setUp=False ):
104
        "Return whether interface is up"
105
        if setUp:
106
            self.ifconfig( 'up' )
107
        return "UP" in self.ifconfig()
108

    
109
    def rename( self, newname ):
110
        "Rename interface"
111
        self.ifconfig( 'down' )
112
        result = self.cmd( 'ip link set', self.name, 'name', newname )
113
        self.name = newname
114
        self.ifconfig( 'up' )
115
        return result
116

    
117
    # The reason why we configure things in this way is so
118
    # That the parameters can be listed and documented in
119
    # the config method.
120
    # Dealing with subclasses and superclasses is slightly
121
    # annoying, but at least the information is there!
122

    
123
    def setParam( self, results, method, **param ):
124
        """Internal method: configure a *single* parameter
125
           results: dict of results to update
126
           method: config method name
127
           param: arg=value (ignore if value=None)
128
           value may also be list or dict"""
129
        name, value = param.items()[ 0 ]
130
        f = getattr( self, method, None )
131
        if not f or value is None:
132
            return
133
        if type( value ) is list:
134
            result = f( *value )
135
        elif type( value ) is dict:
136
            result = f( **value )
137
        else:
138
            result = f( value )
139
        results[ name ] = result
140
        return result
141

    
142
    def config( self, mac=None, ip=None, ifconfig=None,
143
                up=True, **_params ):
144
        """Configure Node according to (optional) parameters:
145
           mac: MAC address
146
           ip: IP address
147
           ifconfig: arbitrary interface configuration
148
           Subclasses should override this method and call
149
           the parent class's config(**params)"""
150
        # If we were overriding this method, we would call
151
        # the superclass config method here as follows:
152
        # r = Parent.config( **params )
153
        r = {}
154
        self.setParam( r, 'setMAC', mac=mac )
155
        self.setParam( r, 'setIP', ip=ip )
156
        self.setParam( r, 'isUp', up=up )
157
        self.setParam( r, 'ifconfig', ifconfig=ifconfig )
158
        self.updateIP()
159
        self.updateMAC()
160
        return r
161

    
162
    def delete( self ):
163
        "Delete interface"
164
        self.cmd( 'ip link del ' + self.name )
165
        # Does it help to sleep to let things run?
166
        sleep( 0.001 )
167

    
168
    def __repr__( self ):
169
        return '<%s %s>' % ( self.__class__.__name__, self.name )
170

    
171
    def __str__( self ):
172
        return self.name
173

    
174

    
175
class TCIntf( Intf ):
176
    """Interface customized by tc (traffic control) utility
177
       Allows specification of bandwidth limits (various methods)
178
       as well as delay, loss and max queue length"""
179

    
180
    def bwCmds( self, bw=None, speedup=0, use_hfsc=False, use_tbf=False,
181
                enable_ecn=False, enable_red=False ):
182
        "Return tc commands to set bandwidth"
183

    
184
        cmds, parent = [], ' root '
185

    
186
        if bw and ( bw < 0 or bw > 1000 ):
187
            error( 'Bandwidth', bw, 'is outside range 0..1000 Mbps\n' )
188

    
189
        elif bw is not None:
190
            # BL: this seems a bit brittle...
191
            if ( speedup > 0 and
192
                 self.node.name[0:2] == 'sw' ):
193
                bw = speedup
194
            if use_hfsc:
195
                cmds = [ '%s qdisc add dev %s root handle 1:0 hfsc default 1',
196
                          'class add dev %s parent 1:0 classid 1:1 hfsc sc '
197
                          + 'rate %fMbit ul rate %fMbit' % ( bw, bw ) ]
198
            elif use_tbf:
199
                latency_us = 10 * 1500 * 8 / bw
200
                cmds = ['%s qdisc add dev %s root handle 1: tbf ' +
201
                        'rate %fMbit burst 15000 latency %fus' %
202
                         (bw, latency_us) ]
203
            else:
204
                cmds = [ '%s qdisc add dev %s root handle 1:0 htb default 1',
205
                         '%s class add dev %s parent 1:0 classid 1:1 htb ' +
206
                         'rate %fMbit burst 15k' % bw ]
207
            parent = ' parent 1:1 '
208

    
209
            # ECN or RED
210
            if enable_ecn:
211
                cmds = [ '%s qdisc add dev %s' + parent +
212
                          'handle 10: red limit 1000000 ' +
213
                          'min 20000 max 25000 avpkt 1000 ' +
214
                          'burst 20 ' +
215
                          'bandwidth %fmbit probability 1 ecn' % bw ]
216
                parent = ' parent 10: '
217
            elif enable_red:
218
                cmds = [ '%s qdisc add dev %s' + parent +
219
                          'handle 10: red limit 1000000 ' +
220
                          'min 20000 max 25000 avpkt 1000 ' +
221
                          'burst 20 ' +
222
                          'bandwidth %fmbit probability 1' % bw ]
223
                parent = ' parent 10: '
224

    
225
        return cmds, parent
226

    
227
    @staticmethod
228
    def delayCmds( parent, delay=None, loss=None,
229
                   max_queue_size=None ):
230
        "Internal method: return tc commands for delay and loss"
231
        cmds = []
232
        if delay and delay < 0:
233
            error( 'Negative delay', delay, '\n' )
234
        elif loss and ( loss < 0 or loss > 100 ):
235
            error( 'Bad loss percentage', loss, '%%\n' )
236
        else:
237
            # Delay/loss/max queue size
238
            netemargs = '%s%s%s' % (
239
                'delay %s ' % delay if delay is not None else '',
240
                'loss %d ' % loss if loss is not None else '',
241
                'limit %d' % max_queue_size if max_queue_size is not None
242
                 else '' )
243
            if netemargs:
244
                cmds = [ '%s qdisc add dev %s ' + parent + ' netem ' +
245
                          netemargs ]
246
        return cmds
247

    
248
    def tc( self, cmd, tc='tc' ):
249
        "Execute tc command for our interface"
250
        c = cmd % (tc, self)  # Add in tc command and our name
251
        debug(" *** executing command: %s\n" % c)
252
        return self.cmd( c )
253

    
254
    def config( self, bw=None, delay=None, loss=None, disable_gro=True,
255
                speedup=0, use_hfsc=False, use_tbf=False, enable_ecn=False,
256
                enable_red=False, max_queue_size=None, **params ):
257
        "Configure the port and set its properties."
258

    
259
        result = Intf.config( self, **params)
260

    
261
        # Disable GRO
262
        if disable_gro:
263
            self.cmd( 'ethtool -K %s gro off' % self )
264

    
265
        # Optimization: return if nothing else to configure
266
        # Question: what happens if we want to reset things?
267
        if ( bw is None and not delay and not loss
268
             and max_queue_size is None ):
269
            return
270

    
271
        # Clear existing configuration
272
        cmds = [ '%s qdisc del dev %s root' ]
273

    
274
        # Bandwidth limits via various methods
275
        bwcmds, parent = self.bwCmds( bw=bw, speedup=speedup,
276
                                 use_hfsc=use_hfsc, use_tbf=use_tbf,
277
                                 enable_ecn=enable_ecn,
278
                                 enable_red=enable_red )
279
        cmds += bwcmds
280

    
281
        # Delay/loss/max_queue_size using netem
282
        cmds += self.delayCmds( delay=delay, loss=loss,
283
                                 max_queue_size=max_queue_size,
284
                                 parent=parent )
285

    
286
        # Ugly but functional: display configuration info
287
        stuff = ( ( [ '%.2fMbit' % bw ] if bw is not None else [] ) +
288
                  ( [ '%s delay' % delay ] if delay is not None else [] ) +
289
                  ( ['%d%% loss' % loss ] if loss is not None else [] ) +
290
                  ( [ 'ECN' ] if enable_ecn  else [ 'RED' ]
291
                    if enable_red else [] ) )
292
        info( '(' + ' '.join( stuff ) + ') ' )
293

    
294
        # Execute all the commands in our node
295
        debug("at map stage w/cmds: %s\n" % cmds)
296
        tcoutputs = [ self.tc(cmd) for cmd in cmds ]
297
        debug( "cmds:", cmds, '\n' )
298
        debug( "outputs:", tcoutputs, '\n' )
299
        result[ 'tcoutputs'] = tcoutputs
300

    
301
        return result
302

    
303

    
304
class Link( object ):
305

    
306
    """A basic link is just a veth pair.
307
       Other types of links could be tunnels, link emulators, etc.."""
308

    
309
    def __init__( self, node1, node2, port1=None, port2=None,
310
                  intfName1=None, intfName2=None,
311
                  intf=Intf, cls1=None, cls2=None, params1=None,
312
                  params2=None ):
313
        """Create veth link to another node, making two new interfaces.
314
           node1: first node
315
           node2: second node
316
           port1: node1 port number (optional)
317
           port2: node2 port number (optional)
318
           intf: default interface class/constructor
319
           cls1, cls2: optional interface-specific constructors
320
           intfName1: node1 interface name (optional)
321
           intfName2: node2  interface name (optional)
322
           params1: parameters for interface 1
323
           params2: parameters for interface 2"""
324
        # This is a bit awkward; it seems that having everything in
325
        # params would be more orthogonal, but being able to specify
326
        # in-line arguments is more convenient!
327
        if port1 is None:
328
            port1 = node1.newPort()
329
        if port2 is None:
330
            port2 = node2.newPort()
331
        if not intfName1:
332
            intfName1 = self.intfName( node1, port1 )
333
        if not intfName2:
334
            intfName2 = self.intfName( node2, port2 )
335

    
336
        self.makeIntfPair( intfName1, intfName2 )
337

    
338
        if not cls1:
339
            cls1 = intf
340
        if not cls2:
341
            cls2 = intf
342
        if not params1:
343
            params1 = {}
344
        if not params2:
345
            params2 = {}
346

    
347
        intf1 = cls1( name=intfName1, node=node1, port=port1,
348
                      link=self, **params1  )
349
        intf2 = cls2( name=intfName2, node=node2, port=port2,
350
                      link=self, **params2 )
351

    
352
        # All we are is dust in the wind, and our two interfaces
353
        self.intf1, self.intf2 = intf1, intf2
354

    
355
    @classmethod
356
    def intfName( cls, node, n ):
357
        "Construct a canonical interface name node-ethN for interface n."
358
        return node.name + '-eth' + repr( n )
359

    
360
    @classmethod
361
    def makeIntfPair( cls, intf1, intf2 ):
362
        """Create pair of interfaces
363
           intf1: name of interface 1
364
           intf2: name of interface 2
365
           (override this class method [and possibly delete()]
366
           to change link type)"""
367
        makeIntfPair( intf1, intf2  )
368

    
369
    def delete( self ):
370
        "Delete this link"
371
        self.intf1.delete()
372
        self.intf2.delete()
373

    
374
    def __str__( self ):
375
        return '%s<->%s' % ( self.intf1, self.intf2 )
376

    
377
class TCLink( Link ):
378
    "Link with symmetric TC interfaces configured via opts"
379
    def __init__( self, node1, node2, port1=None, port2=None,
380
                  intfName1=None, intfName2=None, **params ):
381
        Link.__init__( self, node1, node2, port1=None, port2=None,
382
                       intfName1=None, intfName2=None,
383
                       cls1=TCIntf,
384
                       cls2=TCIntf,
385
                       params1=params,
386
                       params2=params)