This file is indexed.

/usr/lib/python2.7/idlelib/rpc.py is in idle-python2.7 2.7.3-0ubuntu3.9.

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
"""RPC Implemention, originally written for the Python Idle IDE

For security reasons, GvR requested that Idle's Python execution server process
connect to the Idle process, which listens for the connection.  Since Idle has
has only one client per server, this was not a limitation.

   +---------------------------------+ +-------------+
   | SocketServer.BaseRequestHandler | | SocketIO    |
   +---------------------------------+ +-------------+
                   ^                   | register()  |
                   |                   | unregister()|
                   |                   +-------------+
                   |                      ^  ^
                   |                      |  |
                   | + -------------------+  |
                   | |                       |
   +-------------------------+        +-----------------+
   | RPCHandler              |        | RPCClient       |
   | [attribute of RPCServer]|        |                 |
   +-------------------------+        +-----------------+

The RPCServer handler class is expected to provide register/unregister methods.
RPCHandler inherits the mix-in class SocketIO, which provides these methods.

See the Idle run.main() docstring for further information on how this was
accomplished in Idle.

"""

import sys
import os
import socket
import select
import SocketServer
import struct
import cPickle as pickle
import threading
import Queue
import traceback
import copy_reg
import types
import marshal


def unpickle_code(ms):
    co = marshal.loads(ms)
    assert isinstance(co, types.CodeType)
    return co

def pickle_code(co):
    assert isinstance(co, types.CodeType)
    ms = marshal.dumps(co)
    return unpickle_code, (ms,)

# XXX KBK 24Aug02 function pickling capability not used in Idle
#  def unpickle_function(ms):
#      return ms

#  def pickle_function(fn):
#      assert isinstance(fn, type.FunctionType)
#      return repr(fn)

copy_reg.pickle(types.CodeType, pickle_code, unpickle_code)
# copy_reg.pickle(types.FunctionType, pickle_function, unpickle_function)

BUFSIZE = 8*1024
LOCALHOST = '127.0.0.1'

class RPCServer(SocketServer.TCPServer):

    def __init__(self, addr, handlerclass=None):
        if handlerclass is None:
            handlerclass = RPCHandler
        SocketServer.TCPServer.__init__(self, addr, handlerclass)

    def server_bind(self):
        "Override TCPServer method, no bind() phase for connecting entity"
        pass

    def server_activate(self):
        """Override TCPServer method, connect() instead of listen()

        Due to the reversed connection, self.server_address is actually the
        address of the Idle Client to which we are connecting.

        """
        self.socket.connect(self.server_address)

    def get_request(self):
        "Override TCPServer method, return already connected socket"
        return self.socket, self.server_address

    def handle_error(self, request, client_address):
        """Override TCPServer method

        Error message goes to __stderr__.  No error message if exiting
        normally or socket raised EOF.  Other exceptions not handled in
        server code will cause os._exit.

        """
        try:
            raise
        except SystemExit:
            raise
        except:
            erf = sys.__stderr__
            print>>erf, '\n' + '-'*40
            print>>erf, 'Unhandled server exception!'
            print>>erf, 'Thread: %s' % threading.currentThread().getName()
            print>>erf, 'Client Address: ', client_address
            print>>erf, 'Request: ', repr(request)
            traceback.print_exc(file=erf)
            print>>erf, '\n*** Unrecoverable, server exiting!'
            print>>erf, '-'*40
            os._exit(0)

#----------------- end class RPCServer --------------------

objecttable = {}
request_queue = Queue.Queue(0)
response_queue = Queue.Queue(0)


class SocketIO(object):

    nextseq = 0

    def __init__(self, sock, objtable=None, debugging=None):
        self.sockthread = threading.currentThread()
        if debugging is not None:
            self.debugging = debugging
        self.sock = sock
        if objtable is None:
            objtable = objecttable
        self.objtable = objtable
        self.responses = {}
        self.cvars = {}

    def close(self):
        sock = self.sock
        self.sock = None
        if sock is not None:
            sock.close()

    def exithook(self):
        "override for specific exit action"
        os._exit()

    def debug(self, *args):
        if not self.debugging:
            return
        s = self.location + " " + str(threading.currentThread().getName())
        for a in args:
            s = s + " " + str(a)
        print>>sys.__stderr__, s

    def register(self, oid, object):
        self.objtable[oid] = object

    def unregister(self, oid):
        try:
            del self.objtable[oid]
        except KeyError:
            pass

    def localcall(self, seq, request):
        self.debug("localcall:", request)
        try:
            how, (oid, methodname, args, kwargs) = request
        except TypeError:
            return ("ERROR", "Bad request format")
        if oid not in self.objtable:
            return ("ERROR", "Unknown object id: %r" % (oid,))
        obj = self.objtable[oid]
        if methodname == "__methods__":
            methods = {}
            _getmethods(obj, methods)
            return ("OK", methods)
        if methodname == "__attributes__":
            attributes = {}
            _getattributes(obj, attributes)
            return ("OK", attributes)
        if not hasattr(obj, methodname):
            return ("ERROR", "Unsupported method name: %r" % (methodname,))
        method = getattr(obj, methodname)
        try:
            if how == 'CALL':
                ret = method(*args, **kwargs)
                if isinstance(ret, RemoteObject):
                    ret = remoteref(ret)
                return ("OK", ret)
            elif how == 'QUEUE':
                request_queue.put((seq, (method, args, kwargs)))
                return("QUEUED", None)
            else:
                return ("ERROR", "Unsupported message type: %s" % how)
        except SystemExit:
            raise
        except socket.error:
            raise
        except:
            msg = "*** Internal Error: rpc.py:SocketIO.localcall()\n\n"\
                  " Object: %s \n Method: %s \n Args: %s\n"
            print>>sys.__stderr__, msg % (oid, method, args)
            traceback.print_exc(file=sys.__stderr__)
            return ("EXCEPTION", None)

    def remotecall(self, oid, methodname, args, kwargs):
        self.debug("remotecall:asynccall: ", oid, methodname)
        seq = self.asynccall(oid, methodname, args, kwargs)
        return self.asyncreturn(seq)

    def remotequeue(self, oid, methodname, args, kwargs):
        self.debug("remotequeue:asyncqueue: ", oid, methodname)
        seq = self.asyncqueue(oid, methodname, args, kwargs)
        return self.asyncreturn(seq)

    def asynccall(self, oid, methodname, args, kwargs):
        request = ("CALL", (oid, methodname, args, kwargs))
        seq = self.newseq()
        if threading.currentThread() != self.sockthread:
            cvar = threading.Condition()
            self.cvars[seq] = cvar
        self.debug(("asynccall:%d:" % seq), oid, methodname, args, kwargs)
        self.putmessage((seq, request))
        return seq

    def asyncqueue(self, oid, methodname, args, kwargs):
        request = ("QUEUE", (oid, methodname, args, kwargs))
        seq = self.newseq()
        if threading.currentThread() != self.sockthread:
            cvar = threading.Condition()
            self.cvars[seq] = cvar
        self.debug(("asyncqueue:%d:" % seq), oid, methodname, args, kwargs)
        self.putmessage((seq, request))
        return seq

    def asyncreturn(self, seq):
        self.debug("asyncreturn:%d:call getresponse(): " % seq)
        response = self.getresponse(seq, wait=0.05)
        self.debug(("asyncreturn:%d:response: " % seq), response)
        return self.decoderesponse(response)

    def decoderesponse(self, response):
        how, what = response
        if how == "OK":
            return what
        if how == "QUEUED":
            return None
        if how == "EXCEPTION":
            self.debug("decoderesponse: EXCEPTION")
            return None
        if how == "EOF":
            self.debug("decoderesponse: EOF")
            self.decode_interrupthook()
            return None
        if how == "ERROR":
            self.debug("decoderesponse: Internal ERROR:", what)
            raise RuntimeError, what
        raise SystemError, (how, what)

    def decode_interrupthook(self):
        ""
        raise EOFError

    def mainloop(self):
        """Listen on socket until I/O not ready or EOF

        pollresponse() will loop looking for seq number None, which
        never comes, and exit on EOFError.

        """
        try:
            self.getresponse(myseq=None, wait=0.05)
        except EOFError:
            self.debug("mainloop:return")
            return

    def getresponse(self, myseq, wait):
        response = self._getresponse(myseq, wait)
        if response is not None:
            how, what = response
            if how == "OK":
                response = how, self._proxify(what)
        return response

    def _proxify(self, obj):
        if isinstance(obj, RemoteProxy):
            return RPCProxy(self, obj.oid)
        if isinstance(obj, types.ListType):
            return map(self._proxify, obj)
        # XXX Check for other types -- not currently needed
        return obj

    def _getresponse(self, myseq, wait):
        self.debug("_getresponse:myseq:", myseq)
        if threading.currentThread() is self.sockthread:
            # this thread does all reading of requests or responses
            while 1:
                response = self.pollresponse(myseq, wait)
                if response is not None:
                    return response
        else:
            # wait for notification from socket handling thread
            cvar = self.cvars[myseq]
            cvar.acquire()
            while myseq not in self.responses:
                cvar.wait()
            response = self.responses[myseq]
            self.debug("_getresponse:%s: thread woke up: response: %s" %
                       (myseq, response))
            del self.responses[myseq]
            del self.cvars[myseq]
            cvar.release()
            return response

    def newseq(self):
        self.nextseq = seq = self.nextseq + 2
        return seq

    def putmessage(self, message):
        self.debug("putmessage:%d:" % message[0])
        try:
            s = pickle.dumps(message)
        except pickle.PicklingError:
            print >>sys.__stderr__, "Cannot pickle:", repr(message)
            raise
        s = struct.pack("<i", len(s)) + s
        while len(s) > 0:
            try:
                r, w, x = select.select([], [self.sock], [])
                n = self.sock.send(s[:BUFSIZE])
            except (AttributeError, TypeError):
                raise IOError, "socket no longer exists"
            except socket.error:
                raise
            else:
                s = s[n:]

    buffer = ""
    bufneed = 4
    bufstate = 0 # meaning: 0 => reading count; 1 => reading data

    def pollpacket(self, wait):
        self._stage0()
        if len(self.buffer) < self.bufneed:
            r, w, x = select.select([self.sock.fileno()], [], [], wait)
            if len(r) == 0:
                return None
            try:
                s = self.sock.recv(BUFSIZE)
            except socket.error:
                raise EOFError
            if len(s) == 0:
                raise EOFError
            self.buffer += s
            self._stage0()
        return self._stage1()

    def _stage0(self):
        if self.bufstate == 0 and len(self.buffer) >= 4:
            s = self.buffer[:4]
            self.buffer = self.buffer[4:]
            self.bufneed = struct.unpack("<i", s)[0]
            self.bufstate = 1

    def _stage1(self):
        if self.bufstate == 1 and len(self.buffer) >= self.bufneed:
            packet = self.buffer[:self.bufneed]
            self.buffer = self.buffer[self.bufneed:]
            self.bufneed = 4
            self.bufstate = 0
            return packet

    def pollmessage(self, wait):
        packet = self.pollpacket(wait)
        if packet is None:
            return None
        try:
            message = pickle.loads(packet)
        except pickle.UnpicklingError:
            print >>sys.__stderr__, "-----------------------"
            print >>sys.__stderr__, "cannot unpickle packet:", repr(packet)
            traceback.print_stack(file=sys.__stderr__)
            print >>sys.__stderr__, "-----------------------"
            raise
        return message

    def pollresponse(self, myseq, wait):
        """Handle messages received on the socket.

        Some messages received may be asynchronous 'call' or 'queue' requests,
        and some may be responses for other threads.

        'call' requests are passed to self.localcall() with the expectation of
        immediate execution, during which time the socket is not serviced.

        'queue' requests are used for tasks (which may block or hang) to be
        processed in a different thread.  These requests are fed into
        request_queue by self.localcall().  Responses to queued requests are
        taken from response_queue and sent across the link with the associated
        sequence numbers.  Messages in the queues are (sequence_number,
        request/response) tuples and code using this module removing messages
        from the request_queue is responsible for returning the correct
        sequence number in the response_queue.

        pollresponse() will loop until a response message with the myseq
        sequence number is received, and will save other responses in
        self.responses and notify the owning thread.

        """
        while 1:
            # send queued response if there is one available
            try:
                qmsg = response_queue.get(0)
            except Queue.Empty:
                pass
            else:
                seq, response = qmsg
                message = (seq, ('OK', response))
                self.putmessage(message)
            # poll for message on link
            try:
                message = self.pollmessage(wait)
                if message is None:  # socket not ready
                    return None
            except EOFError:
                self.handle_EOF()
                return None
            except AttributeError:
                return None
            seq, resq = message
            how = resq[0]
            self.debug("pollresponse:%d:myseq:%s" % (seq, myseq))
            # process or queue a request
            if how in ("CALL", "QUEUE"):
                self.debug("pollresponse:%d:localcall:call:" % seq)
                response = self.localcall(seq, resq)
                self.debug("pollresponse:%d:localcall:response:%s"
                           % (seq, response))
                if how == "CALL":
                    self.putmessage((seq, response))
                elif how == "QUEUE":
                    # don't acknowledge the 'queue' request!
                    pass
                continue
            # return if completed message transaction
            elif seq == myseq:
                return resq
            # must be a response for a different thread:
            else:
                cv = self.cvars.get(seq, None)
                # response involving unknown sequence number is discarded,
                # probably intended for prior incarnation of server
                if cv is not None:
                    cv.acquire()
                    self.responses[seq] = resq
                    cv.notify()
                    cv.release()
                continue

    def handle_EOF(self):
        "action taken upon link being closed by peer"
        self.EOFhook()
        self.debug("handle_EOF")
        for key in self.cvars:
            cv = self.cvars[key]
            cv.acquire()
            self.responses[key] = ('EOF', None)
            cv.notify()
            cv.release()
        # call our (possibly overridden) exit function
        self.exithook()

    def EOFhook(self):
        "Classes using rpc client/server can override to augment EOF action"
        pass

#----------------- end class SocketIO --------------------

class RemoteObject(object):
    # Token mix-in class
    pass

def remoteref(obj):
    oid = id(obj)
    objecttable[oid] = obj
    return RemoteProxy(oid)

class RemoteProxy(object):

    def __init__(self, oid):
        self.oid = oid

class RPCHandler(SocketServer.BaseRequestHandler, SocketIO):

    debugging = False
    location = "#S"  # Server

    def __init__(self, sock, addr, svr):
        svr.current_handler = self ## cgt xxx
        SocketIO.__init__(self, sock)
        SocketServer.BaseRequestHandler.__init__(self, sock, addr, svr)

    def handle(self):
        "handle() method required by SocketServer"
        self.mainloop()

    def get_remote_proxy(self, oid):
        return RPCProxy(self, oid)

class RPCClient(SocketIO):

    debugging = False
    location = "#C"  # Client

    nextseq = 1 # Requests coming from the client are odd numbered

    def __init__(self, address, family=socket.AF_INET, type=socket.SOCK_STREAM):
        self.listening_sock = socket.socket(family, type)
        self.listening_sock.bind(address)
        self.listening_sock.listen(1)

    def accept(self):
        working_sock, address = self.listening_sock.accept()
        if self.debugging:
            print>>sys.__stderr__, "****** Connection request from ", address
        if address[0] == LOCALHOST:
            SocketIO.__init__(self, working_sock)
        else:
            print>>sys.__stderr__, "** Invalid host: ", address
            raise socket.error

    def get_remote_proxy(self, oid):
        return RPCProxy(self, oid)

class RPCProxy(object):

    __methods = None
    __attributes = None

    def __init__(self, sockio, oid):
        self.sockio = sockio
        self.oid = oid

    def __getattr__(self, name):
        if self.__methods is None:
            self.__getmethods()
        if self.__methods.get(name):
            return MethodProxy(self.sockio, self.oid, name)
        if self.__attributes is None:
            self.__getattributes()
        if name in self.__attributes:
            value = self.sockio.remotecall(self.oid, '__getattribute__',
                                           (name,), {})
            return value
        else:
            raise AttributeError, name

    def __getattributes(self):
        self.__attributes = self.sockio.remotecall(self.oid,
                                                "__attributes__", (), {})

    def __getmethods(self):
        self.__methods = self.sockio.remotecall(self.oid,
                                                "__methods__", (), {})

def _getmethods(obj, methods):
    # Helper to get a list of methods from an object
    # Adds names to dictionary argument 'methods'
    for name in dir(obj):
        attr = getattr(obj, name)
        if hasattr(attr, '__call__'):
            methods[name] = 1
    if type(obj) == types.InstanceType:
        _getmethods(obj.__class__, methods)
    if type(obj) == types.ClassType:
        for super in obj.__bases__:
            _getmethods(super, methods)

def _getattributes(obj, attributes):
    for name in dir(obj):
        attr = getattr(obj, name)
        if not hasattr(attr, '__call__'):
            attributes[name] = 1

class MethodProxy(object):

    def __init__(self, sockio, oid, name):
        self.sockio = sockio
        self.oid = oid
        self.name = name

    def __call__(self, *args, **kwargs):
        value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
        return value


# XXX KBK 09Sep03  We need a proper unit test for this module.  Previously
#                  existing test code was removed at Rev 1.27 (r34098).