aboutsummaryrefslogtreecommitdiffstats
path: root/framework/src/onos/tools/test/topos/opticalUtils.py
blob: bef9deca993363b3c2e3e781b9cd906c6def706e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
#!/usr/bin/python

'''
Notes:

This file contains classes and methods useful for integrating LincOE with Mininet, 
such as startOE, stopOE, LINCLink, and OpticalSwitch

- $ONOS_ROOT ust be set
- Need to run with sudo -E to preserve ONOS_ROOT env var
- We assume LINC-Config-Generator is named LINC-Config-Generator
- We also assume linc-oe is named linc-oe
- LINC-config-generator and linc-oe must be subdirectories of the user's
  home directory

            TODO
        -----------
    - clean up files after runtime
        - maybe save the old files in a separate directory?
    - modify script to allow startOE to run before net.start()
    - add ONOS as a controller in script

            Usage:
        ------------
    - import LINCLink and OpticalSwitch from this module
    - import startOE and stopOE from this module
    - create topology as you would a normal topology. when 
      to an optical switch with topo.addLink, always specify cls=LINCLink
    - when creating an optical switch, use cls=OpticalSwitch in topo.addSwitch
    - for annotations on links and switches, a dictionary must be passed in as
      the annotations argument
    - startOE must be run AFTER net.start() with net as an argument.
    - stopOE can be run at any time

I created a separate function to start lincOE to avoid subclassing Mininet.
In case anyone wants to write something that DOES subclass Mininet, I
thought I would outline how:

If we want an object that starts lincOE within the mininet class itself,
we need to add another object to Mininet that contains all of the json object
information for each switch. We would still subclass switch and link, but these
classes would basically be dummy classes that store their own json information
in the Mininet class object. We may also change the default switch class to add
it's tap interfaces from lincOE during startup. The start() method for mininet would 
grab all of the information from these switches and links, write configuration files
for lincOE using the json module, start lincOE, then run the start methodfor each
switch. The new start() method for each switch would parse through the sys.config
file that was created and find the tap interface it needs to connect to, similar 
to the findTap function that I currently use. After all of the controllers and 
switches have been started, the new Mininet start() method should also push the 
Topology configuration file to ONOS.

'''
import sys
import re
import json
import os
from time import sleep
import urllib2

from mininet.node import Switch, RemoteController
from mininet.topo import Topo
from mininet.util import quietRun
from mininet.net import Mininet
from mininet.log import  setLogLevel, info, error, warn
from mininet.link import Link, Intf
from mininet.cli import CLI

# Sleep time and timeout values in seconds
SLEEP_TIME = 2
TIMEOUT = 60

REST_USER = 'onos'
REST_PW = 'rocks'

class OpticalSwitch(Switch):
    """
    For now, same as Switch class.
    """
    pass

class OpticalIntf(Intf):
    """
    For now,same as Intf class.
    """
    pass

class OpticalLink(Link):
    """
    For now, same as Link.
    """
    pass

class LINCSwitch(OpticalSwitch):
    """
    LINCSwitch class
    """
    # FIXME:Sometimes LINC doesn't remove pipes and on restart increase the pipe
    # number from erlang.pipe.1.* to erlang.pipe.2.*, so should read and write
    # from latest pipe files. For now we are removing all the pipes before
    # starting LINC.
    ### User Name ###
    user = os.getlogin()
    ### pipes ###
    readPipe = "/tmp/home/{}/linc-oe/rel/linc/erlang.pipe.1.r".format(user)
    writePipe = "/tmp/home/{}/linc-oe/rel/linc/erlang.pipe.1.w".format(user)
    ### sys.config path ###
    sysConfig = "/home/{}/linc-oe/rel/linc/releases/1.0/sys.config".format(user)
    ### method, mapping dpid to LINC switchId ###
    @staticmethod
    def dpids_to_ids(sysConfig):
        '''
        return the dict containing switch dpids as key and LINC switch id as values
        '''
        dpids_to_ids = {}
        fd = None
        try:
            with open(sysConfig, 'r', 0) as fd:
                switch_id = 1
                for line in fd:
                    dpid = re.search(r'([0-9A-Fa-f]{2}[:-]){7}([0-9A-Fa-f]{2})+', line, re.I)
                    if dpid:
                        dpids_to_ids[dpid.group().replace(':', '')] = switch_id
                        switch_id += 1
            return dpids_to_ids     
        except:
            print "Error working with {}\nError: {}\n".format(sysConfig, sys.exc_info())
            fd.close()
            return None
    ### dict of containing dpids as key and corresponding LINC switchId as values ###
    dpidsToLINCSwitchId = dpids_to_ids.__func__(sysConfig)
    @staticmethod
    def findDir(directory, userName):
        "finds and returns the path of any directory in the user's home directory"
        homeDir = '/home/' + userName
        Dir = quietRun('find %s -maxdepth 1 -name %s -type d' % (homeDir, directory)).strip('\n')
        DirList = Dir.split('\n')
        if not Dir:
            return None
        elif len(DirList) > 1 :
            warn('***WARNING: Found multiple instances of %s; using %s\n'
                     % (directory, DirList[ 0 ]))
            return DirList[ 0 ]
        else:
            return Dir
    ### ONOS Directory ###
    try:
        onosDir = os.environ[ 'ONOS_ROOT' ]
    except:
        onosDir = findDir('onos', user)
        if not onosDir:
            error('Please set ONOS_ROOT environment variable!\n')
        else:
            os.environ[ 'ONOS_ROOT' ] = onosDir
    ### LINC-directory
    lincDir = findDir.__func__('linc-oe', user)
    if not lincDir:
        error("***ERROR: Could not find linc-oe in user's home directory\n")
    ### LINC config generator directory###
    configGen = findDir.__func__('LINC-config-generator', user)
    if not configGen:
        error("***ERROR: Could not find LINC-config-generator in user's home directory\n")
    # list of all the controllers
    controllers = None
    def __init__(self, name, dpid=None, allowed=True,
                  switchType='ROADM', topo=None, annotations={}, controller=None, **params):
        params[ 'inNamespace' ] = False
        Switch.__init__(self, name, dpid=dpid, **params)
        self.name = name
        self.annotations = annotations
        self.allowed = allowed
        self.switchType = switchType
        self.configDict = {}  # dictionary that holds all of the JSON configuration data
        self.crossConnects = []
        self.deletedCrossConnects = []
        self.controller = controller
        self.lincId = self._get_linc_id()  # use to communicate with LINC
        self.lincStarted = False

    def start(self, *opts, **params):
        '''Instead of starting a virtual switch, we build the JSON
           dictionary for the emulated optical switch'''
        # TODO:Once LINC has the ability to spawn network element dynamically
        # we need to use this method to spawn new logical LINC switch rather then
        # bulding JSON.
        # if LINC is started then we can start and stop logical switches else create JSON
        if self.lincStarted:
            return self.start_oe()
        self.configDict[ 'uri' ] = 'of:' + self.dpid
        self.configDict[ 'annotations' ] = self.annotations
        self.configDict[ 'annotations' ].setdefault('name', self.name)
        self.configDict[ 'hw' ] = 'LINC-OE'
        self.configDict[ 'mfr' ] = 'Linc'
        self.configDict[ 'mac' ] = 'ffffffffffff' + self.dpid[-2] + self.dpid[-1]
        self.configDict[ 'type' ] = self.switchType
        self.configDict[ 'ports' ] = []
        for port, intf in self.intfs.items():
            if intf.name == 'lo':
                continue
            else:
                self.configDict[ 'ports' ].append(intf.json())
        self.lincStarted = True

    def stop(self, deleteIntfs=False):
        '''
        stop the existing switch
        '''
        # TODO:Add support for deleteIntf
        self.stop_oe()

    def dpctl( self, *args ):
        "Run dpctl command: ignore for now"
        pass

    def write_to_cli(self, command):
        '''
        send command to LINC
        '''
        fd = None
        try:
            fd = open(self.writePipe, 'w', 0)
            fd.write(command)
            fd.close()
        except:
            print "Error working with {}\nError: {}\n".format(self.writePipe, sys.exc_info())
            if fd:
                fd.close()

    def read_from_cli(self):
        '''
        read the output from the LINC CLI
        '''
        response = None
        fd = None
        try:
            fd = open(self.readPipe, 'r', 0)
            fcntl.fcntl(fd, fcntl.F_SETFL, os.O_NONBLOCK)  # for non-blocking read
            # FIXME:Due to non-blocking read most for the time we read nothing
            response = fd.read()
            fd.close()
        except :
            # print "Error working with {}\nError: {}\n".format(self.readPipe, sys.exc_info())
            if fd:
                fd.close()
        return response

    def _get_linc_id(self):
        '''
        return the corresponding LINC switchId.
        '''
        return LINCSwitch.dpidsToLINCSwitchId.get(self.dpid)
    #--------------------------------------------------------------------------
    # LINC CLI commands
    #--------------------------------------------------------------------------
    def start_oe(self):
        '''
         existing LINC switch
        '''
        #starting Switch
        cmd = "linc:start_switch({}).\r\n".format(self.lincId)
        self.write_to_cli(cmd)
        #hanlding taps interfaces related to the switch
        crossConnectJSON = {}
        linkConfig = []
        for i in range(0,len(self.deletedCrossConnects)):
            crossConnect = self.deletedCrossConnects.pop()
            tap = None
            if isinstance(crossConnect.intf1.node, LINCSwitch):
                intf = crossConnect.intf2
                tapPort = crossConnect.intf1.port
            else:
                intf = crossConnect.intf1
                tapPort = crossConnect.intf2.port
            tap = LINCSwitch.findTap(self, tapPort)
            if tap:
                LINCSwitch.setupInts([tap])
                intf.node.attach(tap)
            self.crossConnects.append(crossConnect)
            linkConfig.append(crossConnect.json())
        #Sending crossConnect info to the ONOS.
        crossConnectJSON['links'] = linkConfig
        with open("crossConnect.json", 'w') as fd:
            json.dump(crossConnectJSON, fd, indent=4, separators=(',', ': '))
        info('*** Pushing crossConnect.json to ONOS\n')
        output = quietRun('%s/tools/test/bin/onos-topo-cfg %s\
         Topology.json' % (self.onosDir, self.controllers[ 0 ].ip), shell=True)

    def stop_oe(self):
        '''
        stop the existing LINC switch
        '''
        cmd = "linc:stop_switch({}).\r\n".format(self.lincId)
        self.write_to_cli(cmd)
        #handling taps if any
        for i in range(0, len(self.crossConnects)):
            crossConnect = self.crossConnects.pop()
            if isinstance(crossConnect.intf1.node, LINCSwitch):
                intf = crossConnect.intf2
                tapPort = crossConnect.intf1.port
            else:
                intf = crossConnect.intf1
                tapPort = crossConnect.intf2.port
            intf.node.detach(LINCSwitch.findTap(self, tapPort))
            self.deletedCrossConnects.append(crossConnect)

    def w_port_up(self, port):
        '''
        port_up
        '''
        cmd = "linc:port_up({},{}).\r\n".format(self.lincId, port)
        self.write_to_cli(cmd)

    def w_port_down(self, port):
        '''
        port_down
        '''
        cmd = "linc:port_down({},{}).\r\n".format(self.lincId, port)
        self.write_to_cli(cmd)

    # helper functions
    @staticmethod
    def switchJSON(switch):
        "Returns the json configuration for a packet switch"
        configDict = {}
        configDict[ 'uri' ] = 'of:' + switch.dpid
        configDict[ 'mac' ] = quietRun('cat /sys/class/net/%s/address' % switch.name).strip('\n').translate(None, ':')
        configDict[ 'hw' ] = 'PK'  # FIXME what about OVS?
        configDict[ 'mfr' ] = 'Linc'  # FIXME what about OVS?
        configDict[ 'type' ] = 'SWITCH'  # FIXME what about OVS?
        annotations = switch.params.get('annotations', {})
        annotations.setdefault('name', switch.name)
        configDict[ 'annotations' ] = annotations
        ports = []
        for port, intf in switch.intfs.items():
            if intf.name == 'lo':
                continue
            portDict = {}
            portDict[ 'port' ] = port
            portDict[ 'type' ] = 'FIBER' if isinstance(intf.link, LINCLink) else 'COPPER'
            intfList = [ intf.link.intf1, intf.link.intf2 ]
            intfList.remove(intf)
            portDict[ 'speed' ] = intfList[ 0 ].speed if isinstance(intf.link, LINCLink) else 0
            ports.append(portDict)
        configDict[ 'ports' ] = ports
        return configDict

    @staticmethod
    def bootOE(net):
        "Start the LINC optical emulator within a mininet instance"
        LINCSwitch.opticalJSON = {}
        linkConfig = []
        devices = []
        #setting up the controllers for LINCSwitch class
        LINCSwitch.controllers = net.controllers

        for switch in net.switches:
            if isinstance(switch, OpticalSwitch):
                devices.append(switch.json())
            else:
                devices.append(LINCSwitch.switchJSON(switch))
        LINCSwitch.opticalJSON[ 'devices' ] = devices

        for link in net.links:
            if isinstance(link, LINCLink) :
                linkConfig.append(link.json())
        LINCSwitch.opticalJSON[ 'links' ] = linkConfig

        info('*** Writing Topology.json file\n')
        with open('Topology.json', 'w') as outfile:
            json.dump(LINCSwitch.opticalJSON, outfile, indent=4, separators=(',', ': '))

        info('*** Converting Topology.json to linc-oe format (TopoConfig.json) file (no oecfg) \n')
        
        topoConfigJson = {};
        dpIdToName = {};

        topoConfigJson["switchConfig"] = LINCSwitch.getSwitchConfig(dpIdToName);
        topoConfigJson["linkConfig"] = LINCSwitch.getLinkConfig(dpIdToName);

        #Writing to TopoConfig.json
        with open( 'TopoConfig.json', 'w' ) as outfile:
            json.dump( topoConfigJson, outfile, indent=4, separators=(',', ': ') )

        info('*** Creating sys.config...\n')
        output = quietRun('%s/config_generator TopoConfig.json %s/sys.config.template %s %s'
                        % (LINCSwitch.configGen, LINCSwitch.configGen, LINCSwitch.controllers[ 0 ].ip, LINCSwitch.controllers[ 0 ].port), shell=True)
        if output:
            error('***ERROR: Error creating sys.config file: %s\n' % output)
            return False

        info ('*** Setting multiple controllers in sys.config...\n')
        searchStr = '\[{"Switch.*$'
        ctrlStr = ''
        for index in range(len(LINCSwitch.controllers)):
            ctrlStr += '{"Switch%d-Controller","%s",%d,tcp},' % (index, net.controllers[index].ip, net.controllers[index].port)
        replaceStr = '[%s]},' % ctrlStr[:-1]  # Cut off last comma
        sedCmd = 'sed -i \'s/%s/%s/\' sys.config' % (searchStr, replaceStr)
        output = quietRun(sedCmd, shell=True)

        info('*** Copying sys.config to linc-oe directory: ', output + '\n')
        output = quietRun('cp -v sys.config %s/rel/linc/releases/1.0/' % LINCSwitch.lincDir, shell=True).strip('\n')
        info(output + '\n')

        info('*** Adding taps and bringing them up...\n')
        LINCSwitch.setupInts(LINCSwitch.getTaps())

        info('*** removing pipes if any \n')
        quietRun('rm /tmp/home/%s/linc-oe/rel/linc/*' % LINCSwitch.user, shell=True)

        info('*** Starting linc OE...\n')
        output = quietRun('%s/rel/linc/bin/linc start' % LINCSwitch.lincDir, shell=True)
        if output:
            error('***ERROR: LINC-OE: %s' % output + '\n')
            quietRun('%s/rel/linc/bin/linc stop' % LINCSwitch.lincDir, shell=True)
            return False

        info('*** Waiting for linc-oe to start...\n')
        LINCSwitch.waitStarted(net)

        info('*** Adding cross-connect (tap) interfaces to packet switches...\n')
        for link in net.links:
            if isinstance(link, LINCLink):
                if link.annotations[ 'optical.type' ] == 'cross-connect':
                    for intf in [ link.intf1, link.intf2 ]:
                        if not isinstance(intf, LINCIntf):
                            intfList = [ intf.link.intf1, intf.link.intf2 ]
                            intfList.remove(intf)
                            intf2 = intfList[ 0 ]
                            intf.node.attach(LINCSwitch.findTap(intf2.node, intf2.node.ports[ intf2 ]))

        info('*** Waiting for all devices to be available in ONOS...\n')
        url = 'http://%s:8181/onos/v1/devices' % LINCSwitch.controllers[0].ip
        time = 0
        # Set up password authentication
        pw_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
        pw_mgr.add_password(None, url, REST_USER, REST_PW)
        handler = urllib2.HTTPBasicAuthHandler(pw_mgr)
        opener = urllib2.build_opener(handler)
        opener.open(url)
        urllib2.install_opener(opener)
        while True:
            response = json.load(urllib2.urlopen(url))
            devs = response.get('devices')

            # Wait for all devices to be registered
            if (len(devices) != len(devs)):
                continue

            # Wait for all devices to available
            available = True
            for d in devs:
                available &= d['available']
            if available:
                break

            if (time >= TIMEOUT):
                error('***ERROR: ONOS did not register devices within %s seconds\n' % TIMEOUT)
                break

            time += SLEEP_TIME
            sleep(SLEEP_TIME)

        info('*** Pushing Topology.json to ONOS\n')
        for index in range(len(LINCSwitch.controllers)):
            output = quietRun('%s/tools/test/bin/onos-topo-cfg %s Topology.json &' % (LINCSwitch.onosDir, LINCSwitch.controllers[ index ].ip), shell=True)
            # successful output contains the two characters '{}'
            # if there is more output than this, there is an issue
            if output.strip('{}'):
                warn('***WARNING: Could not push topology file to ONOS: %s\n' % output)

    #converts node ids to linc-oe format, with colons every two chars
    @staticmethod
    def dpId(id):
        nodeDpid = ""
        id = id.split("/", 1)[0]
        for i in range(3, len(id) - 1, 2):
            nodeDpid += (id[i:(i + 2):]) + ":"
        return nodeDpid[0:-1];

    @staticmethod
    def getSwitchConfig (dpIdToName):
        switchConfig = [];
        #Iterate through all switches and convert the ROADM switches to linc-oe format
        for switch in LINCSwitch.opticalJSON["devices"]:
            if switch.get("type", "none") == "ROADM":
                builtSwitch = {}

                #set basic switch params based on annotations
                builtSwitch["allowed"] = True;
                builtSwitch["latitude"] = switch["annotations"].get("latitude", 0.0);
                builtSwitch["longitude"] = switch["annotations"].get("longitude", 0.0);

                #assumed that all switches have this entry
                nodeId = switch["uri"]

                #convert the nodeId to linc-oe format
                nodeDpid = LINCSwitch.dpId(nodeId);

                builtSwitch["name"] = switch.get("name", "none");

                #keep track of the name corresponding to each switch dpid
                dpIdToName[nodeDpid] = builtSwitch["name"];

                builtSwitch["nodeDpid"] = nodeDpid

                #set switch params and type
                builtSwitch["params"] = {};
                builtSwitch["params"]["numregens"] = switch["annotations"].get("optical.regens", 0);
                builtSwitch["type"] = "Roadm"

                #append to list of switches
                switchConfig.append(builtSwitch);
        return switchConfig

    @staticmethod
    def getLinkConfig (dpIdToName):
        newLinkConfig = [];
        #Iterate through all optical links and convert them to linc-oe format
        for link in LINCSwitch.opticalJSON["links"]:
            if link.get("type", "none") == "OPTICAL":
                builtLink = {}

                #set basic link params for src and dst
                builtLink["allowed"] = True;
                builtLink["nodeDpid1"] = LINCSwitch.dpId(link["src"])
                builtLink["nodeDpid2"] = LINCSwitch.dpId(link["dst"])

                #set more params such as name/bandwidth/port/waves if they exist
                params = {}
                params["nodeName1"] = dpIdToName.get(builtLink["nodeDpid1"], "none")
                params["nodeName2"] = dpIdToName.get(builtLink["nodeDpid2"], "none")
                
                params["port1"] = int(link["src"].split("/")[1])
                params["port2"]  = int(link["dst"].split("/")[1])

                if "bandwidth" in link["annotations"]:
                    params["bandwidth"] = link["annotations"]["bandwidth"]

                if "optical.waves" in link["annotations"]:
                    params["numWaves"] = link["annotations"]["optical.waves"]
                
                builtLink["params"] = params

                #set type of link (WDM or pktOpt)
                if link["annotations"].get("optical.type", "cross-connect") == "WDM":
                    builtLink["type"] = "wdmLink"
                else:
                    builtLink["type"] = "pktOptLink"

                newLinkConfig.append(builtLink);
        return newLinkConfig


    @staticmethod
    def waitStarted(net, timeout=TIMEOUT):
        "wait until all tap interfaces are available"
        tapCount = 0
        time = 0
        for link in net.links:
            if isinstance(link, LINCLink):
                if link.annotations[ 'optical.type' ] == 'cross-connect':
                    tapCount += 1

        while True:
            if str(tapCount) == quietRun('ip addr | grep tap | wc -l', shell=True).strip('\n'):
                return True
            if timeout:
                if time >= TIMEOUT:
                    error('***ERROR: LINC OE did not start within %s seconds\n' % TIMEOUT)
                    return False
                time += SLEEP_TIME
            sleep(SLEEP_TIME)

    @staticmethod
    def shutdownOE():
        "stop the optical emulator"
        info('*** Stopping linc OE...\n')
        quietRun('%s/rel/linc/bin/linc stop' % LINCSwitch.lincDir, shell=True)

    @staticmethod
    def setupInts(intfs):
        '''
        add taps and bring them up.
        '''
        for i in intfs:
            quietRun('ip tuntap add dev %s mode tap' % i)
            quietRun('ip link set dev %s up' % i)
            info('*** Intf %s set\n' % i)

    @staticmethod
    def getTaps(path=None):
        '''
        return list of all the tops in sys.config
        '''
        if path is None:
            path = '%s/rel/linc/releases/1.0/sys.config' % LINCSwitch.lincDir
        fd = open(path, 'r', 0)
        sys_data = fd.read()
        taps = re.findall('tap\d+', sys_data)
        fd.close()
        return taps

    @staticmethod
    def findUser():
        "Try to return logged-in (usually non-root) user"
        try:
            # If we're running sudo
            return os.environ[ 'SUDO_USER' ]
        except:
            try:
                # Logged-in user (if we have a tty)
                return quietRun('who am i').split()[ 0 ]
            except:
                # Give up and return effective user
                return quietRun('whoami')


    @staticmethod
    def findTap(node, port, path=None):
        '''utility function to parse through a sys.config
           file to find tap interfaces for a switch'''
        switch = False
        portLine = ''
        intfLines = []

        if path is None:
            path = '%s/rel/linc/releases/1.0/sys.config' % LINCSwitch.lincDir

        with open(path) as f:
            for line in f:
                if 'tap' in line:
                    intfLines.append(line)
                if node.dpid in line.translate(None, ':'):
                    switch = True
                    continue
                if switch:
                    if 'switch' in line:
                        switch = False
                    if 'port_no,%s}' % port in line:
                        portLine = line
                        break

        if portLine:
            m = re.search('port,\d+', portLine)
            port = m.group(0).split(',')[ 1 ]
        else:
            error('***ERROR: Could not find any ports in sys.config\n')
            return

        for intfLine in intfLines:
            if 'port,%s' % port in intfLine:
                return re.findall('tap\d+', intfLine)[ 0 ]

    def json(self):
        "return json configuration dictionary for switch"
        return self.configDict

    def terminate(self):
        pass



class LINCLink(Link):
    """
    LINC link class
    """
    def __init__(self, node1, node2, port1=None, port2=None, allowed=True,
                  intfName1=None, intfName2=None, linkType='OPTICAL',
                  annotations={}, speed1=0, speed2=0, **params):
        "Creates a dummy link without a virtual ethernet pair."
        self.allowed = allowed
        self.annotations = annotations
        self.linkType = linkType
        self.port1 = port1
        self.port2 = port2
        params1 = { 'speed': speed1 }
        params2 = { 'speed': speed2 }
        # self.isCrossConnect = True if self.annotations.get('optical.type') == 'cross-connect' else False
        if isinstance(node1, LINCSwitch) and isinstance(node2, LINCSwitch):
            self.isCrossConnect = False
        else:
            self.isCrossConnect = True
        if isinstance(node1, LINCSwitch):
            cls1 = LINCIntf
            if self.isCrossConnect:
                node1.crossConnects.append(self)
        else:
            cls1 = Intf
            # bad hack to stop error message from appearing when we try to set up intf in a packet switch, 
            # and there is no interface there( because we do not run makeIntfPair ). This way, we just set lo up
            intfName1 = 'lo'
        if isinstance(node2, LINCSwitch):
            cls2 = LINCIntf
            if self.isCrossConnect:
                node2.crossConnects.append(self)
        else:
            cls2 = Intf
            intfName2 = 'lo'
        Link.__init__(self, node1, node2, port1=port1, port2=port2,
                       intfName1=intfName1, intfName2=intfName2, cls1=cls1,
                       cls2=cls2, params1=params1, params2=params2)

    @classmethod
    def makeIntfPair(_cls, intfName1, intfName2, *args, **kwargs):
        pass

    def json(self):
        "build and return the json configuration dictionary for this link"
        configData = {}
        configData[ 'src' ] = ('of:' + self.intf1.node.dpid +
                                '/%s' % self.intf1.node.ports[ self.intf1 ])
        configData[ 'dst' ] = ('of:' + self.intf2.node.dpid +
                                '/%s' % self.intf2.node.ports[ self.intf2 ])
        configData[ 'type' ] = self.linkType
        configData[ 'annotations' ] = self.annotations
        return configData

class LINCIntf(OpticalIntf):
    """
    LINC interface class
    """
    def __init__(self, name=None, node=None, speed=0,
                  port=None, link=None, **params):
        self.node = node
        self.speed = speed
        self.port = port
        self.link = link
        self.name = name
        node.addIntf(self, port=port)
        self.params = params
        self.ip = None

    def json(self):
        "build and return the JSON information for this interface( not used right now )"
        configDict = {}
        configDict[ 'port' ] = self.port
        configDict[ 'speed' ] = self.speed
        configDict[ 'type' ] = 'FIBER'
        return configDict

    def config(self, *args, **kwargs):
        "dont configure a dummy interface"
        pass

    def ifconfig(self, status):
        "configure the status"
        if status == "up":
            return self.node.w_port_up(self.port)
        elif status == "down":
            return self.node.w_port_down(self.port)


class MininetOE(Mininet):
    "Mininet with Linc-OE support (starts and stops linc-oe)"

    def start(self):
        Mininet.start(self)
        LINCSwitch.bootOE(self)

    def stop(self):
        Mininet.stop(self)
        LINCSwitch.shutdownOE()

    def addControllers(self, controllers):
        i = 0
        for ctrl in controllers:
            self.addController(RemoteController('c%d' % i, ip=ctrl))
            i += 1

if __name__ == '__main__':
    pass