This file is indexed.

/usr/lib/python2.7/dist-packages/ClusterShell/Propagation.py is in clustershell 1.7-1-1.

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
#!/usr/bin/env python
#
# Copyright CEA/DAM/DIF (2010-2015)
#  Contributor: Henri DOREAU <henri.doreau@cea.fr>
#  Contributor: Stephane THIELL <sthiell@stanford.edu>
#
# This file is part of the ClusterShell library.
#
# This software is governed by the CeCILL-C license under French law and
# abiding by the rules of distribution of free software.  You can  use,
# modify and/ or redistribute the software under the terms of the CeCILL-C
# license as circulated by CEA, CNRS and INRIA at the following URL
# "http://www.cecill.info".
#
# As a counterpart to the access to the source code and  rights to copy,
# modify and redistribute granted by the license, users are provided only
# with a limited warranty  and the software's author,  the holder of the
# economic rights,  and the successive licensors  have only  limited
# liability.
#
# In this respect, the user's attention is drawn to the risks associated
# with loading,  using,  modifying and/or developing or reproducing the
# software by the user in light of its specific status of free software,
# that may mean  that it is complicated to manipulate,  and  that  also
# therefore means  that it is reserved for developers  and  experienced
# professionals having in-depth computer knowledge. Users are therefore
# encouraged to load and test the software's suitability as regards their
# requirements in conditions enabling the security of their systems and/or
# data to be ensured and,  more generally, to use and operate it in the
# same conditions as regards security.
#
# The fact that you are presently reading this means that you have had
# knowledge of the CeCILL-C license and that you accept its terms.

"""
ClusterShell Propagation module. Use the topology tree to send commands
through gateways and gather results.
"""

from collections import deque
import logging

from ClusterShell.Defaults import DEFAULTS
from ClusterShell.NodeSet import NodeSet
from ClusterShell.Communication import Channel
from ClusterShell.Communication import ControlMessage, StdOutMessage
from ClusterShell.Communication import StdErrMessage, RetcodeMessage
from ClusterShell.Communication import StartMessage, EndMessage
from ClusterShell.Communication import RoutedMessageBase, ErrorMessage
from ClusterShell.Communication import ConfigurationMessage, TimeoutMessage
from ClusterShell.Topology import TopologyError


class RouteResolvingError(Exception):
    """error raised on invalid conditions during routing operations"""

class PropagationTreeRouter(object):
    """performs routes resolving operations within a propagation tree.
    This object provides a next_hop method, that will look for the best
    directly connected node to use to forward a message to a remote
    node.

    Upon instanciation, the router will parse the topology tree to
    generate its routing table.
    """
    def __init__(self, root, topology, fanout=0):
        self.root = root
        self.topology = topology
        self.fanout = fanout
        self.nodes_fanin = {}
        self.table = None

        self.table_generate(root, topology)
        self._unreachable_hosts = NodeSet()

    def table_generate(self, root, topology):
        """The router relies on a routing table. The keys are the
        destination nodes and the values are the next hop gateways to
        use to reach these nodes.
        """
        self.table = {}
        try:
            root_group = topology.find_nodegroup(root)
        except TopologyError:
            msgfmt = "Invalid root or gateway node: %s"
            raise RouteResolvingError(msgfmt % root)

        for group in root_group.children():
            self.table[group.nodeset] = NodeSet()
            stack = [group]
            while len(stack) > 0:
                curr = stack.pop()
                self.table[group.nodeset].add(curr.children_ns())
                stack += curr.children()

        # reverse table (it was crafted backward)
        self.table = dict((v, k) for k, v in self.table.iteritems())

    def dispatch(self, dst):
        """dispatch nodes from a target nodeset to the directly
        connected gateways.

        The method acts as an iterator, returning a gateway and the
        associated hosts. It should provide a rather good load balancing
        between the gateways.
        """
        ### Disabled to handle all remaining nodes as directly connected nodes
        ## Check for directly connected targets
        #res = [tmp & dst for tmp in self.table.values()]
        #nexthop = NodeSet()
        #[nexthop.add(x) for x in res]
        #if len(nexthop) > 0:
        #    yield nexthop, nexthop

        # Check for remote targets, that require a gateway to be reached
        for network in self.table.iterkeys():
            dst_inter = network & dst
            dst.difference_update(dst_inter)
            for host in dst_inter.nsiter():
                yield self.next_hop(host), host

        # remaining nodes are considered as directly connected nodes
        if dst:
            yield dst, dst

    def next_hop(self, dst):
        """perform the next hop resolution. If several hops are
        available, then, the one with the least number of current jobs
        will be returned
        """
        if dst in self._unreachable_hosts:
            raise RouteResolvingError(
                'Invalid destination: %s, host is unreachable' % dst)

        # can't resolve if source == destination
        if self.root == dst:
            raise RouteResolvingError(
                'Invalid resolution request: %s -> %s' % (self.root, dst))

        ## ------------------
        # the routing table is organized this way:
        #
        #  NETWORK    | NEXT HOP
        # ------------+-----------
        # node[0-9]   | gateway0
        # node[10-19] | gateway[1-2]
        #            ...
        # ---------
        for network, nexthops in self.table.iteritems():
            # destination contained in current network
            if dst in network:
                res = self._best_next_hop(nexthops)
                if res is None:
                    raise RouteResolvingError('No route available to %s' % \
                        str(dst))
                self.nodes_fanin[res] += len(dst)
                return res
            # destination contained in current next hops (ie. directly
            # connected)
            if dst in nexthops:
                return dst

        raise RouteResolvingError(
            'No route from %s to host %s' % (self.root, dst))

    def mark_unreachable(self, dst):
        """mark node dst as unreachable and don't advertise routes
        through it anymore. The cache will be updated only when
        necessary to avoid performing expensive traversals.
        """
        # Simply mark dst as unreachable in a dedicated NodeSet. This
        # list will be consulted by the resolution method
        self._unreachable_hosts.add(dst)

    def _best_next_hop(self, candidates):
        """find out a good next hop gateway"""
        backup = None
        backup_connections = 1e400 # infinity

        candidates = candidates.difference(self._unreachable_hosts)

        for host in candidates:
            # the router tracks established connections in the
            # nodes_fanin table to avoid overloading a gateway
            connections = self.nodes_fanin.setdefault(host, 0)
            # FIXME
            #if connections < self.fanout:
            #    # currently, the first one is the best
            #    return host
            if backup_connections > connections:
                backup = host
                backup_connections = connections
        return backup


class PropagationChannel(Channel):
    """Admin node propagation logic. Instances are able to handle
    incoming messages from a directly connected gateway, process them
    and reply.

    In order to take decisions, the instance acts as a finite states
    machine, whose current state evolves according to received data.

    -- INTERNALS --
    Instance can be in one of the 4 different states:
      - init (implicit)
        This is the very first state. The instance enters the init
        state at start() method, and will then send the configuration
        to the remote node.  Once the configuration is sent away, the
        state changes to cfg.

      - cfg
        During this second state, the instance will wait for a valid
        acknowledgement from the gateway to the previously sent
        configuration message. If such a message is delivered, the
        control message (the one that contains the actions to perform)
        is sent, and the state is set to ctl.

      - ctl
        Third state, the instance is waiting for a valid ack for from
        the gateway to the ctl packet. Then, the state switch to gtr
        (gather).

      - gtr
        Final state: wait for results from the subtree and store them.
    """
    def __init__(self, task, gateway):
        """
        """
        Channel.__init__(self)
        self.task = task
        self.gateway = gateway
        self.workers = {}
        self._cfg_write_hist = deque() # track write requests
        self._sendq = deque()
        self._rc = None
        self.logger = logging.getLogger(__name__)

    def send_queued(self, ctl):
        """helper used to send a message, using msg queue if needed"""
        if self.setup and not self._sendq:
            # send now if channel is setup and sendq empty
            self.send(ctl)
        else:
            self.logger.debug("send_queued: %d", len(self._sendq))
            self._sendq.appendleft(ctl)

    def send_dequeue(self):
        """helper used to send one queued message (if any)"""
        if self._sendq:
            ctl = self._sendq.pop()
            self.logger.debug("dequeuing sendq: %s", ctl)
            self.send(ctl)

    def start(self):
        """start propagation channel"""
        self._init()
        self._open()
        # Immediately send CFG
        cfg = ConfigurationMessage(self.gateway)
        cfg.data_encode(self.task.topology)
        self.send(cfg)

    def recv(self, msg):
        """process incoming messages"""
        self.logger.debug("[DBG] rcvd from: %s", msg)
        if msg.type == EndMessage.ident:
            #??#self.ptree.notify_close()
            self.logger.debug("got EndMessage; closing")
            # abort worker (now working)
            self.worker.abort()
        elif self.setup:
            self.recv_ctl(msg)
        elif self.opened:
            self.recv_cfg(msg)
        elif msg.type == StartMessage.ident:
            self.opened = True
            self.logger.debug('channel started (version %s on remote gateway)',
                              self._xml_reader.version)
        else:
            self.logger.error('unexpected message: %s', str(msg))

    def shell(self, nodes, command, worker, timeout, stderr, gw_invoke_cmd,
              remote):
        """command execution through channel"""
        self.logger.debug("shell nodes=%s timeout=%s worker=%s remote=%s",
                          nodes, timeout, id(worker), remote)

        self.workers[id(worker)] = worker

        ctl = ControlMessage(id(worker))
        ctl.action = 'shell'
        ctl.target = nodes

        # copy only subset of task info dict
        info = dict((k, self.task._info[k]) for k in DEFAULTS._task_info_pkeys)

        ctl_data = {
            'cmd': command,
            'invoke_gateway': gw_invoke_cmd, # XXX
            'taskinfo': info, #self.task._info,
            'stderr': stderr,
            'timeout': timeout,
            'remote': remote,
        }
        ctl.data_encode(ctl_data)
        self.send_queued(ctl)

    def write(self, nodes, buf, worker):
        """write buffer through channel to nodes on standard input"""
        self.logger.debug("write buflen=%d", len(buf))
        assert id(worker) in self.workers

        ctl = ControlMessage(id(worker))
        ctl.action = 'write'
        ctl.target = nodes

        ctl_data = {
            'buf': buf,
        }
        ctl.data_encode(ctl_data)
        self._cfg_write_hist.appendleft((ctl.msgid, nodes, len(buf), worker))
        self.send_queued(ctl)

    def set_write_eof(self, nodes, worker):
        """send EOF through channel to specified nodes"""
        self.logger.debug("set_write_eof")
        assert id(worker) in self.workers

        ctl = ControlMessage(id(worker))
        ctl.action = 'eof'
        ctl.target = nodes
        self.send_queued(ctl)

    def recv_cfg(self, msg):
        """handle incoming messages for state 'propagate configuration'"""
        self.logger.debug("recv_cfg")
        if msg.type == 'ACK':
            self.logger.debug("CTL - connection with gateway fully established")
            self.setup = True
            self.send_dequeue()
        else:
            self.logger.debug("_state_config error (msg=%s)", msg)

    def recv_ctl(self, msg):
        """handle incoming messages for state 'control'"""
        self.logger.debug("recv_ctl")
        if msg.type == 'ACK':
            self.logger.debug("got ack (%s)", msg.type)
            # check if ack matches write history msgid to generate ev_written
            if self._cfg_write_hist and msg.ack == self._cfg_write_hist[-1][0]:
                _, nodes, bytes_count, metaworker = self._cfg_write_hist.pop()
                for node in nodes:
                    # we are losing track of the gateway here, we could override
                    # on_written in WorkerTree if needed (eg. for stats)
                    metaworker._on_written(node, bytes_count, 'stdin')
            self.send_dequeue()
        elif isinstance(msg, RoutedMessageBase):
            metaworker = self.workers[msg.srcid]
            if msg.type == StdOutMessage.ident:
                if metaworker.eh:
                    nodeset = NodeSet(msg.nodes)
                    decoded = msg.data_decode() + '\n'
                    self.logger.debug("StdOutMessage: \"%s\"", decoded)
                    for line in decoded.splitlines():
                        for node in nodeset:
                            metaworker._on_remote_node_msgline(node,
                                                               line,
                                                               'stdout',
                                                               self.gateway)
            elif msg.type == StdErrMessage.ident:
                if metaworker.eh:
                    nodeset = NodeSet(msg.nodes)
                    decoded = msg.data_decode() + '\n'
                    self.logger.debug("StdErrMessage: \"%s\"", decoded)
                    for line in decoded.splitlines():
                        for node in nodeset:
                            metaworker._on_remote_node_msgline(node,
                                                               line,
                                                               'stderr',
                                                               self.gateway)
            elif msg.type == RetcodeMessage.ident:
                rc = msg.retcode
                for node in NodeSet(msg.nodes):
                    metaworker._on_remote_node_rc(node, rc, self.gateway)
            elif msg.type == TimeoutMessage.ident:
                self.logger.debug("TimeoutMessage for %s", msg.nodes)
                for node in NodeSet(msg.nodes):
                    metaworker._on_remote_node_timeout(node, self.gateway)
        elif msg.type == ErrorMessage.ident:
            # tree runtime error, could generate a new event later
            raise TopologyError("%s: %s" % (self.gateway, msg.reason))
        else:
            self.logger.debug("recv_ctl: unhandled msg %s", msg)
        """
        return
        if self.ptree.upchannel is not None:
            self.logger.debug("_state_gather ->upchan %s" % msg)
            self.ptree.upchannel.send(msg) # send to according event handler passed by shell()
        else:
            assert False
        """

    def ev_hup(self, worker):
        """Channel command is closing"""
        self._rc = worker.current_rc

    def ev_close(self, worker):
        """Channel is closing"""
        # do not use worker buffer or rc accessors here as we doesn't use
        # common stream names
        gateway = str(worker.nodes)
        self.logger.debug("ev_close gateway=%s %s", gateway, self)
        self.logger.debug("ev_close rc=%s", self._rc) # may be None

        if self._rc: # got explicit error code
            # ev_routing?
            self.logger.debug("unreachable gateway %s", gateway)
            worker.task.router.mark_unreachable(gateway)
            self.logger.debug("worker.task.gateways=%s", worker.task.gateways)
            # TODO: find best gateway, update WorkerTree counters, relaunch...