This file is indexed.

/usr/lib/python3/dist-packages/scapy/sendrecv.py is in python3-scapy 0.23-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  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
## This file is part of Scapy
## See http://www.secdev.org/projects/scapy for more informations
## Copyright (C) Philippe Biondi <phil@secdev.org>
## This program is published under a GPLv2 license

"""
Functions to send and receive packets.
"""

import pickle,os,sys,time,subprocess,itertools
from select import select
from .data import *
import scapy.arch
from .config import conf
from .packet import Gen
from .utils import warning,get_temp_file,PcapReader,wrpcap
from . import plist
from .error import log_runtime,log_interactive
from .base_classes import SetGen

#################
## Debug class ##
#################

class debug:
    recv=[]
    sent=[]
    match=[]


####################
## Send / Receive ##
####################




def sndrcv(pks, pkt, timeout = None, inter = 0, verbose=None, chainCC=0, retry=0, multi=0):
    if not isinstance(pkt, Gen):
        pkt = SetGen(pkt)
        
    if verbose is None:
        verbose = conf.verb
    debug.recv = plist.PacketList([],"Unanswered")
    debug.sent = plist.PacketList([],"Sent")
    debug.match = plist.SndRcvList([])
    nbrecv=0
    ans = []
    # do it here to fix random fields, so that parent and child have the same
    all_stimuli = tobesent = [p for p in pkt]
    notans = len(tobesent)

    hsent={}
    for i in tobesent:
        h = i.hashret()
        if h in hsent:
            hsent[h].append(i)
        else:
            hsent[h] = [i]
    if retry < 0:
        retry = -retry
        autostop=retry
    else:
        autostop=0


    while retry >= 0:
        found=0
    
        if timeout is not None and timeout < 0:
            timeout = None
            
        rdpipe,wrpipe = os.pipe()
        rdpipe=os.fdopen(rdpipe, "rb")
        wrpipe=os.fdopen(wrpipe,"wb")

        pid=1
        try:
            pid = os.fork()
            if pid == 0:
                try:
                    sys.stdin.close()
                    rdpipe.close()
                    try:
                        i = 0
                        if verbose:
                            print("Begin emission:")
                        for p in tobesent:
                            pks.send(p)
                            i += 1
                            time.sleep(inter)
                        if verbose:
                            print("Finished to send %i packets." % i)
                    except SystemExit:
                        pass
                    except KeyboardInterrupt:
                        pass
                    except:
                        log_runtime.exception("--- Error in child %i" % os.getpid())
                        log_runtime.info("--- Error in child %i" % os.getpid())
                finally:
                    try:
                        os.setpgrp() # Chance process group to avoid ctrl-C
                        sent_times = [p.sent_time for p in all_stimuli if p.sent_time]
                        pickle.dump( (conf.netcache,sent_times), wrpipe )
                        wrpipe.close()
                    except:
                        pass
            elif pid < 0:
                log_runtime.error("fork error")
            else:
                wrpipe.close()
                stoptime = 0
                remaintime = None
                inmask = [rdpipe,pks]
                try:
                    try:
                        while 1:
                            if stoptime:
                                remaintime = stoptime-time.time()
                                if remaintime <= 0:
                                    break
                            r = None
                            if scapy.arch.FREEBSD or scapy.arch.DARWIN:
                                inp, out, err = select(inmask,[],[], 0.05)
                                if len(inp) == 0 or pks in inp:
                                    r = pks.nonblock_recv()
                            else:
                                inp, out, err = select(inmask,[],[], remaintime)
                                if len(inp) == 0:
                                    break
                                if pks in inp:
                                    r = pks.recv(MTU)
                            if rdpipe in inp:
                                if timeout:
                                    stoptime = time.time()+timeout
                                del(inmask[inmask.index(rdpipe)])
                            if r is None:
                                continue
                            ok = 0
                            h = r.hashret()
                            if h in hsent:
                                hlst = hsent[h]
                                for i in range(len(hlst)):
                                    if r.answers(hlst[i]):
                                        ans.append((hlst[i],r))
                                        if verbose > 1:
                                            os.write(1, b"*")
                                        ok = 1                                
                                        if not multi:
                                            del(hlst[i])
                                            notans -= 1;
                                        else:
                                            if not hasattr(hlst[i], '_answered'):
                                                notans -= 1;
                                            hlst[i]._answered = 1;
                                        break
                            if notans == 0 and not multi:
                                break
                            if not ok:
                                if verbose > 1:
                                    os.write(1, b".")
                                nbrecv += 1
                                if conf.debug_match:
                                    debug.recv.append(r)
                    except KeyboardInterrupt:
                        if chainCC:
                            raise
                finally:
                    try:
                        nc,sent_times = pickle.load(rdpipe)
                    except EOFError:
                        warning("Child died unexpectedly. Packets may have not been sent %i"%os.getpid())
                    else:
                        conf.netcache.update(nc)
                        for p,t in zip(all_stimuli, sent_times):
                            p.sent_time = t
                    os.waitpid(pid,0)
        finally:
            if pid == 0:
                os._exit(0)

        #remain = reduce(list.__add__, hsent.values(), [])
        remain = list(itertools.chain(*[ i for i in hsent.values() ]))
        if multi:
            #remain = filter(lambda p: not hasattr(p, '_answered'), remain);
            remain = [ p for p in remain if not hasattr(p, '_answered')]
            
        if autostop and len(remain) > 0 and len(remain) != len(tobesent):
            retry = autostop
            
        tobesent = remain
        if len(tobesent) == 0:
            break
        retry -= 1
        
    if conf.debug_match:
        debug.sent=plist.PacketList(remain[:],"Sent")
        debug.match=plist.SndRcvList(ans[:])

    #clean the ans list to delete the field _answered
    if (multi):
        for s,r in ans:
            if hasattr(s, '_answered'):
                del(s._answered)
    
    if verbose:
        print("\nReceived %i packets, got %i answers, remaining %i packets" % (nbrecv+len(ans), len(ans), notans))
    return plist.SndRcvList(ans),plist.PacketList(remain,"Unanswered")


def __gen_send(s, x, inter=0, loop=0, count=None, verbose=None, realtime=None, *args, **kargs):
    if type(x) is bytes:
        x = conf.raw_layer(load=x)
    if type(x) is str:
        x = conf.raw_layer(load=x.encode('ascii'))
    if not isinstance(x, Gen):
        x = SetGen(x)
    if verbose is None:
        verbose = conf.verb
    n = 0
    if count is not None:
        loop = -count
    elif not loop:
        loop=-1
    try:
        while loop:
            dt0 = None
            for p in x:
                if realtime:
                    ct = time.time()
                    if dt0:
                        st = dt0+p.time-ct
                        if st > 0:
                            time.sleep(st)
                    else:
                        dt0 = ct-p.time 
                s.send(p)
                n += 1
                if verbose:
                    os.write(1,b".")
                time.sleep(inter)
            if loop < 0:
                loop += 1
    except KeyboardInterrupt:
        pass
    s.close()
    if verbose:
        print("\nSent %i packets." % n)
        
@conf.commands.register
def send(x, inter=0, loop=0, count=None, verbose=None, realtime=None, *args, **kargs):
    """Send packets at layer 3
send(packets, [inter=0], [loop=0], [verbose=conf.verb]) -> None"""
    __gen_send(conf.L3socket(*args, **kargs), x, inter=inter, loop=loop, count=count,verbose=verbose, realtime=realtime)

@conf.commands.register
def sendp(x, inter=0, loop=0, iface=None, iface_hint=None, count=None, verbose=None, realtime=None, *args, **kargs):
    """Send packets at layer 2
sendp(packets, [inter=0], [loop=0], [verbose=conf.verb]) -> None"""
    if iface is None and iface_hint is not None:
        iface = conf.route.route(iface_hint)[0]
    __gen_send(conf.L2socket(iface=iface, *args, **kargs), x, inter=inter, loop=loop, count=count, verbose=verbose, realtime=realtime)

@conf.commands.register
def sendpfast(x, pps=None, mbps=None, realtime=None, loop=0, file_cache=False, iface=None, verbose=True):
    """Send packets at layer 2 using tcpreplay for performance
    pps:  packets per second
    mpbs: MBits per second
    realtime: use packet's timestamp, bending time with realtime value
    loop: number of times to process the packet list
    file_cache: cache packets in RAM instead of reading from disk at each iteration
    iface: output interface
    verbose: if False, discard tcpreplay output """
    if iface is None:
        iface = conf.iface
    argv = [conf.prog.tcpreplay, "--intf1=%s" % iface ]
    if pps is not None:
        argv.append("--pps=%i" % pps)
    elif mbps is not None:
        argv.append("--mbps=%f" % mbps)
    elif realtime is not None:
        argv.append("--multiplier=%i" % realtime)
    else:
        argv.append("--topspeed")
    if not verbose:
        argv.append("-q")
    if loop:
        argv.append("--loop=%i" % loop)
        if file_cache:
            argv.append("--enable-file-cache")

    f = get_temp_file()
    argv.append(f)
    wrpcap(f, x)
    with open(os.devnull, "wb") as null:
        proc_output = null if not verbose else None
        try:
            subprocess.check_call(argv,
                                  stdout=proc_output,
                                  stderr=proc_output)
        except KeyboardInterrupt:
            log_interactive.info("Interrupted by user")
        except Exception as e:
            log_interactive.error("while trying to exec [%s]: %s" % (argv[0],e))
        finally:
            os.unlink(f)





@conf.commands.register
def sr(x,filter=None, iface=None, nofilter=0, *args,**kargs):
    """Send and receive packets at layer 3
nofilter: put 1 to avoid use of bpf filters
retry:    if positive, how many times to resend unanswered packets
          if negative, how many times to retry when no more packets are answered
timeout:  how much time to wait after the last packet has been sent
verbose:  set verbosity level
multi:    whether to accept multiple answers for the same stimulus
filter:   provide a BPF filter
iface:    listen answers only on the given interface"""
    if not "timeout" in kargs:
        kargs["timeout"] = -1
    s = conf.L3socket(filter=filter, iface=iface, nofilter=nofilter)
    a,b=sndrcv(s,x,*args,**kargs)
    s.close()
    return a,b

@conf.commands.register
def sr1(x,filter=None,iface=None, nofilter=0, *args,**kargs):
    """Send packets at layer 3 and return only the first answer
nofilter: put 1 to avoid use of bpf filters
retry:    if positive, how many times to resend unanswered packets
          if negative, how many times to retry when no more packets are answered
timeout:  how much time to wait after the last packet has been sent
verbose:  set verbosity level
multi:    whether to accept multiple answers for the same stimulus
filter:   provide a BPF filter
iface:    listen answers only on the given interface"""
    if not "timeout" in kargs:
        kargs["timeout"] = -1
    s=conf.L3socket(filter=filter, nofilter=nofilter, iface=iface)
    a,b=sndrcv(s,x,*args,**kargs)
    s.close()
    if len(a) > 0:
        return a[0][1]
    else:
        return None

@conf.commands.register
def srp(x,iface=None, iface_hint=None, filter=None, nofilter=0, type=ETH_P_ALL, *args,**kargs):
    """Send and receive packets at layer 2
nofilter: put 1 to avoid use of bpf filters
retry:    if positive, how many times to resend unanswered packets
          if negative, how many times to retry when no more packets are answered
timeout:  how much time to wait after the last packet has been sent
verbose:  set verbosity level
multi:    whether to accept multiple answers for the same stimulus
filter:   provide a BPF filter
iface:    work only on the given interface"""
    if not "timeout" in kargs:
        kargs["timeout"] = -1
    if iface is None and iface_hint is not None:
        iface = conf.route.route(iface_hint)[0]
    s = conf.L2socket(iface=iface, filter=filter, nofilter=nofilter, type=type)
    a,b=sndrcv(s ,x,*args,**kargs)
    s.close()
    return a,b

@conf.commands.register
def srp1(*args,**kargs):
    """Send and receive packets at layer 2 and return only the first answer
nofilter: put 1 to avoid use of bpf filters
retry:    if positive, how many times to resend unanswered packets
          if negative, how many times to retry when no more packets are answered
timeout:  how much time to wait after the last packet has been sent
verbose:  set verbosity level
multi:    whether to accept multiple answers for the same stimulus
filter:   provide a BPF filter
iface:    work only on the given interface"""
    if not "timeout" in kargs:
        kargs["timeout"] = -1
    a,b=srp(*args,**kargs)
    if len(a) > 0:
        return a[0][1]
    else:
        return None

def __sr_loop(srfunc, pkts, prn=lambda x:x[1].summary(), prnfail=lambda x:x.summary(), inter=1, timeout=None, count=None, verbose=None, store=1, *args, **kargs):
    n = 0
    r = 0
    ct = conf.color_theme
    if verbose is None:
        verbose = conf.verb
    parity = 0
    ans=[]
    unans=[]
    if timeout is None:
        timeout = min(2*inter, 5)
    try:
        while 1:
            parity ^= 1
            col = [ct.even,ct.odd][parity]
            if count is not None:
                if count == 0:
                    break
                count -= 1
            start = time.time()
            print("\rsend...\r", end = " ")
            res = srfunc(pkts, timeout=timeout, verbose=0, chainCC=1, *args, **kargs)
            n += len(res[0])+len(res[1])
            r += len(res[0])
            if verbose > 1 and prn and len(res[0]) > 0:
                msg = "RECV %i:" % len(res[0])
                print( "\r"+ct.success(msg), end = " ")
                for p in res[0]:
                    print(col(prn(p)))
                    print(" "*len(msg), end = " ")
            if verbose > 1 and prnfail and len(res[1]) > 0:
                msg = "fail %i:" % len(res[1])
                print("\r"+ct.fail(msg), end = " ")
                for p in res[1]:
                    print(col(prnfail(p)))
                    print(" "*len(msg), end = " ")
            if verbose > 1 and not (prn or prnfail):
                print("recv:%i  fail:%i" % tuple(map(len, res[:2])))
            if store:
                ans += res[0]
                unans += res[1]
            end=time.time()
            if end-start < inter:
                time.sleep(inter+start-end)
    except KeyboardInterrupt:
        pass
 
    if verbose and n>0:
        print(ct.normal("\nSent %i packets, received %i packets. %3.1f%% hits." % (n,r,100.0*r/n)))
    return plist.SndRcvList(ans),plist.PacketList(unans)

@conf.commands.register
def srloop(pkts, *args, **kargs):
    """Send a packet at layer 3 in loop and print the answer each time
srloop(pkts, [prn], [inter], [count], ...) --> None"""
    return __sr_loop(sr, pkts, *args, **kargs)

@conf.commands.register
def srploop(pkts, *args, **kargs):
    """Send a packet at layer 2 in loop and print the answer each time
srloop(pkts, [prn], [inter], [count], ...) --> None"""
    return __sr_loop(srp, pkts, *args, **kargs)


#def sndrcvflood(pks, pkt, prn=lambda (s,r):r.summary(), chainCC=0, store=1, unique=0):
def sndrcvflood(pks, pkt, prn=lambda a:a[1].summary(), chainCC=0, store=1, unique=0):
    if not isinstance(pkt, Gen):
        pkt = SetGen(pkt)
    tobesent = [p for p in pkt]
    received = plist.SndRcvList()
    seen = {}

    hsent={}
    for i in tobesent:
        h = i.hashret()
        if h in hsent:
            hsent[h].append(i)
        else:
            hsent[h] = [i]

    def send_in_loop(tobesent):
        while 1:
            for p in tobesent:
                yield p

    packets_to_send = send_in_loop(tobesent)

    ssock = rsock = pks.fileno()

    try:
        while 1:
            readyr,readys,_ = select([rsock],[ssock],[])
            if ssock in readys:
                pks.send(next(packets_to_send))
                
            if rsock in readyr:
                p = pks.recv(MTU)
                if p is None:
                    continue
                h = p.hashret()
                if h in hsent:
                    hlst = hsent[h]
                    for i in hlst:
                        if p.answers(i):
                            res = prn((i,p))
                            if unique:
                                if res in seen:
                                    continue
                                seen[res] = None
                            if res is not None:
                                print(res)
                            if store:
                                received.append((i,p))
    except KeyboardInterrupt:
        if chainCC:
            raise
    return received

@conf.commands.register
def srflood(x,filter=None, iface=None, nofilter=None, *args,**kargs):
    """Flood and receive packets at layer 3
prn:      function applied to packets received. Ret val is printed if not None
store:    if 1 (default), store answers and return them
unique:   only consider packets whose print 
nofilter: put 1 to avoid use of bpf filters
filter:   provide a BPF filter
iface:    listen answers only on the given interface"""
    s = conf.L3socket(filter=filter, iface=iface, nofilter=nofilter)
    r=sndrcvflood(s,x,*args,**kargs)
    s.close()
    return r

@conf.commands.register
def srpflood(x,filter=None, iface=None, iface_hint=None, nofilter=None, *args,**kargs):
    """Flood and receive packets at layer 2
prn:      function applied to packets received. Ret val is printed if not None
store:    if 1 (default), store answers and return them
unique:   only consider packets whose print 
nofilter: put 1 to avoid use of bpf filters
filter:   provide a BPF filter
iface:    listen answers only on the given interface"""
    if iface is None and iface_hint is not None:
        iface = conf.route.route(iface_hint)[0]    
    s = conf.L2socket(filter=filter, iface=iface, nofilter=nofilter)
    r=sndrcvflood(s,x,*args,**kargs)
    s.close()
    return r

           


@conf.commands.register
def sniff(count=0, store=1, offline=None, prn = None, lfilter=None, L2socket=None, timeout=None,
          opened_socket=None, stop_filter=None, exceptions=False, stop_callback=None, *arg, **karg):
    """Sniff packets
sniff([count=0,] [prn=None,] [store=1,] [offline=None,] [lfilter=None,] + L2ListenSocket args) -> list of packets

  count: number of packets to capture. 0 means infinity
  store: wether to store sniffed packets or discard them
    prn: function to apply to each packet. If something is returned,
         it is displayed. Ex:
         ex: prn = lambda x: x.summary()
lfilter: python function applied to each packet to determine
         if further action may be done
         ex: lfilter = lambda x: x.haslayer(Padding)
offline: pcap file to read packets from, instead of sniffing them
timeout: stop sniffing after a given time (default: None)
L2socket: use the provided L2socket
opened_socket: provide an object ready to use .recv() on
stop_filter: python function applied to each packet to determine
             if we have to stop the capture after this packet
             ex: stop_filter = lambda x: x.haslayer(TCP)
exceptions: reraise caught exceptions such as KeyboardInterrupt
            when a user interrupts sniffing
stop_callback: Call every loop to determine if we need
               to stop the capture
    """
    c = 0
    
    if opened_socket is not None:
        s = opened_socket
    else:
        if offline is None:
            if L2socket is None:
                L2socket = conf.L2listen
            s = L2socket(type=ETH_P_ALL, *arg, **karg)
        else:
            s = PcapReader(offline)

    lst = []
    if timeout is not None:
        stoptime = time.time()+timeout
    remain = None
    try:
        while 1:
            if timeout is not None:
                remain = stoptime-time.time()
                if remain <= 0:
                    break
            if stop_callback and stop_callback():
                break
            sel = select([s],[],[],remain)
            if s in sel[0]:
                p = s.recv(MTU)
                if p is None:
                    break
                if lfilter and not lfilter(p):
                    continue
                if store:
                    lst.append(p)
                c += 1
                if prn:
                    r = prn(p)
                    if r is not None:
                        print(r)
                if stop_filter and stop_filter(p):
                    break
                if count > 0 and c >= count:
                    break
    except KeyboardInterrupt:
        if exceptions:
            raise
        else:
            pass
    finally:
        if opened_socket is None:
            s.close()

    return plist.PacketList(lst,"Sniffed")


@conf.commands.register
def bridge_and_sniff(if1, if2, count=0, store=1, offline=None, prn = None, lfilter=None, L2socket=None, timeout=None,
                     stop_filter=None, stop_callback=None, *args, **kargs):
    """Forward traffic between two interfaces and sniff packets exchanged
bridge_and_sniff([count=0,] [prn=None,] [store=1,] [offline=None,] [lfilter=None,] + L2Socket args) -> list of packets

  count: number of packets to capture. 0 means infinity
  store: wether to store sniffed packets or discard them
    prn: function to apply to each packet. If something is returned,
         it is displayed. Ex:
         ex: prn = lambda x: x.summary()
lfilter: python function applied to each packet to determine
         if further action may be done
         ex: lfilter = lambda x: x.haslayer(Padding)
timeout: stop sniffing after a given time (default: None)
L2socket: use the provided L2socket
stop_filter: python function applied to each packet to determine
             if we have to stop the capture after this packet
             ex: stop_filter = lambda x: x.haslayer(TCP)
stop_callback: Call every loop to determine if we need
               to stop the capture
    """
    c = 0
    if L2socket is None:
        L2socket = conf.L2socket
    s1 = L2socket(iface=if1)
    s2 = L2socket(iface=if2)
    peerof={s1:s2,s2:s1}
    label={s1:if1, s2:if2}
    
    lst = []
    if timeout is not None:
        stoptime = time.time()+timeout
    remain = None
    try:
        while True:
            if timeout is not None:
                remain = stoptime-time.time()
                if remain <= 0:
                    break
            if stop_callback and stop_callback():
                break
            ins,outs,errs = select([s1,s2],[],[], remain)
            for s in ins:
                p = s.recv()
                if p is not None:
                    peerof[s].send(p.original)
                    if lfilter and not lfilter(p):
                        continue
                    if store:
                        p.sniffed_on = label[s]
                        lst.append(p)
                    c += 1
                    if prn:
                        r = prn(p)
                        if r is not None:
                            print("%s: %s" % (label[s],r))
                    if stop_filter and stop_filter(p):
                        break
                    if count > 0 and c >= count:
                        break
    except KeyboardInterrupt:
        pass
    finally:
        return plist.PacketList(lst,"Sniffed")


@conf.commands.register
def tshark(*args,**kargs):
    """Sniff packets and print them calling pkt.show(), a bit like text wireshark"""
    sniff(prn=lambda x: x.display(),*args,**kargs)