This file is indexed.

/usr/share/pyshared/ovs/daemon.py is in python-openvswitch 2.0.1+git20140120-0ubuntu2.

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
# Copyright (c) 2010, 2011, 2012 Nicira, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import errno
import fcntl
import os
import resource
import signal
import sys
import time

import ovs.dirs
import ovs.fatal_signal
#import ovs.lockfile
import ovs.process
import ovs.socket_util
import ovs.timeval
import ovs.util
import ovs.vlog

vlog = ovs.vlog.Vlog("daemon")

# --detach: Should we run in the background?
_detach = False

# --pidfile: Name of pidfile (null if none).
_pidfile = None

# Our pidfile's inode and device, if we have created one.
_pidfile_dev = None
_pidfile_ino = None

# --overwrite-pidfile: Create pidfile even if one already exists and is locked?
_overwrite_pidfile = False

# --no-chdir: Should we chdir to "/"?
_chdir = True

# --monitor: Should a supervisory process monitor the daemon and restart it if
# it dies due to an error signal?
_monitor = False

# File descriptor used by daemonize_start() and daemonize_complete().
_daemonize_fd = None

RESTART_EXIT_CODE = 5


def make_pidfile_name(name):
    """Returns the file name that would be used for a pidfile if 'name' were
    provided to set_pidfile()."""
    if name is None or name == "":
        return "%s/%s.pid" % (ovs.dirs.RUNDIR, ovs.util.PROGRAM_NAME)
    else:
        return ovs.util.abs_file_name(ovs.dirs.RUNDIR, name)


def set_pidfile(name):
    """Sets up a following call to daemonize() to create a pidfile named
    'name'.  If 'name' begins with '/', then it is treated as an absolute path.
    Otherwise, it is taken relative to ovs.util.RUNDIR, which is
    $(prefix)/var/run by default.

    If 'name' is null, then ovs.util.PROGRAM_NAME followed by ".pid" is
    used."""
    global _pidfile
    _pidfile = make_pidfile_name(name)


def get_pidfile():
    """Returns an absolute path to the configured pidfile, or None if no
    pidfile is configured."""
    return _pidfile


def set_no_chdir():
    """Sets that we do not chdir to "/"."""
    global _chdir
    _chdir = False


def is_chdir_enabled():
    """Will we chdir to "/" as part of daemonizing?"""
    return _chdir


def ignore_existing_pidfile():
    """Normally, daemonize() or daemonize_start() will terminate the program
    with a message if a locked pidfile already exists.  If this function is
    called, an existing pidfile will be replaced, with a warning."""
    global _overwrite_pidfile
    _overwrite_pidfile = True


def set_detach():
    """Sets up a following call to daemonize() to detach from the foreground
    session, running this process in the background."""
    global _detach
    _detach = True


def get_detach():
    """Will daemonize() really detach?"""
    return _detach


def set_monitor():
    """Sets up a following call to daemonize() to fork a supervisory process to
    monitor the daemon and restart it if it dies due to an error signal."""
    global _monitor
    _monitor = True


def _fatal(msg):
    vlog.err(msg)
    sys.stderr.write("%s\n" % msg)
    sys.exit(1)


def _make_pidfile():
    """If a pidfile has been configured, creates it and stores the running
    process's pid in it.  Ensures that the pidfile will be deleted when the
    process exits."""
    pid = os.getpid()

    # Create a temporary pidfile.
    tmpfile = "%s.tmp%d" % (_pidfile, pid)
    ovs.fatal_signal.add_file_to_unlink(tmpfile)
    try:
        # This is global to keep Python from garbage-collecting and
        # therefore closing our file after this function exits.  That would
        # unlock the lock for us, and we don't want that.
        global file_handle

        file_handle = open(tmpfile, "w")
    except IOError, e:
        _fatal("%s: create failed (%s)" % (tmpfile, e.strerror))

    try:
        s = os.fstat(file_handle.fileno())
    except IOError, e:
        _fatal("%s: fstat failed (%s)" % (tmpfile, e.strerror))

    try:
        file_handle.write("%s\n" % pid)
        file_handle.flush()
    except OSError, e:
        _fatal("%s: write failed: %s" % (tmpfile, e.strerror))

    try:
        fcntl.lockf(file_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
    except IOError, e:
        _fatal("%s: fcntl failed: %s" % (tmpfile, e.strerror))

    # Rename or link it to the correct name.
    if _overwrite_pidfile:
        try:
            os.rename(tmpfile, _pidfile)
        except OSError, e:
            _fatal("failed to rename \"%s\" to \"%s\" (%s)"
                   % (tmpfile, _pidfile, e.strerror))
    else:
        while True:
            try:
                os.link(tmpfile, _pidfile)
                error = 0
            except OSError, e:
                error = e.errno
            if error == errno.EEXIST:
                _check_already_running()
            elif error != errno.EINTR:
                break
        if error:
            _fatal("failed to link \"%s\" as \"%s\" (%s)"
                   % (tmpfile, _pidfile, os.strerror(error)))

    # Ensure that the pidfile will get deleted on exit.
    ovs.fatal_signal.add_file_to_unlink(_pidfile)

    # Delete the temporary pidfile if it still exists.
    if not _overwrite_pidfile:
        error = ovs.fatal_signal.unlink_file_now(tmpfile)
        if error:
            _fatal("%s: unlink failed (%s)" % (tmpfile, os.strerror(error)))

    global _pidfile_dev
    global _pidfile_ino
    _pidfile_dev = s.st_dev
    _pidfile_ino = s.st_ino


def daemonize():
    """If configured with set_pidfile() or set_detach(), creates the pid file
    and detaches from the foreground session."""
    daemonize_start()
    daemonize_complete()


def _waitpid(pid, options):
    while True:
        try:
            return os.waitpid(pid, options)
        except OSError, e:
            if e.errno == errno.EINTR:
                pass
            return -e.errno, 0


def _fork_and_wait_for_startup():
    try:
        rfd, wfd = os.pipe()
    except OSError, e:
        sys.stderr.write("pipe failed: %s\n" % os.strerror(e.errno))
        sys.exit(1)

    try:
        pid = os.fork()
    except OSError, e:
        sys.stderr.write("could not fork: %s\n" % os.strerror(e.errno))
        sys.exit(1)

    if pid > 0:
        # Running in parent process.
        os.close(wfd)
        ovs.fatal_signal.fork()
        while True:
            try:
                s = os.read(rfd, 1)
                error = 0
            except OSError, e:
                s = ""
                error = e.errno
            if error != errno.EINTR:
                break
        if len(s) != 1:
            retval, status = _waitpid(pid, 0)
            if retval == pid:
                if os.WIFEXITED(status) and os.WEXITSTATUS(status):
                    # Child exited with an error.  Convey the same error to
                    # our parent process as a courtesy.
                    sys.exit(os.WEXITSTATUS(status))
                else:
                    sys.stderr.write("fork child failed to signal "
                                     "startup (%s)\n"
                                     % ovs.process.status_msg(status))
            else:
                assert retval < 0
                sys.stderr.write("waitpid failed (%s)\n"
                                 % os.strerror(-retval))
                sys.exit(1)

        os.close(rfd)
    else:
        # Running in parent process.
        os.close(rfd)
        ovs.timeval.postfork()
        #ovs.lockfile.postfork()

        global _daemonize_fd
        _daemonize_fd = wfd
    return pid


def _fork_notify_startup(fd):
    if fd is not None:
        error, bytes_written = ovs.socket_util.write_fully(fd, "0")
        if error:
            sys.stderr.write("could not write to pipe\n")
            sys.exit(1)
        os.close(fd)


def _should_restart(status):
    global RESTART_EXIT_CODE

    if os.WIFEXITED(status) and os.WEXITSTATUS(status) == RESTART_EXIT_CODE:
        return True

    if os.WIFSIGNALED(status):
        for signame in ("SIGABRT", "SIGALRM", "SIGBUS", "SIGFPE", "SIGILL",
                        "SIGPIPE", "SIGSEGV", "SIGXCPU", "SIGXFSZ"):
            if os.WTERMSIG(status) == getattr(signal, signame, None):
                return True
    return False


def _monitor_daemon(daemon_pid):
    # XXX should log daemon's stderr output at startup time
    # XXX should use setproctitle module if available
    last_restart = None
    while True:
        retval, status = _waitpid(daemon_pid, 0)
        if retval < 0:
            sys.stderr.write("waitpid failed\n")
            sys.exit(1)
        elif retval == daemon_pid:
            status_msg = ("pid %d died, %s"
                          % (daemon_pid, ovs.process.status_msg(status)))

            if _should_restart(status):
                if os.WCOREDUMP(status):
                    # Disable further core dumps to save disk space.
                    try:
                        resource.setrlimit(resource.RLIMIT_CORE, (0, 0))
                    except resource.error:
                        vlog.warn("failed to disable core dumps")

                # Throttle restarts to no more than once every 10 seconds.
                if (last_restart is not None and
                    ovs.timeval.msec() < last_restart + 10000):
                    vlog.warn("%s, waiting until 10 seconds since last "
                              "restart" % status_msg)
                    while True:
                        now = ovs.timeval.msec()
                        wakeup = last_restart + 10000
                        if now > wakeup:
                            break
                        print "sleep %f" % ((wakeup - now) / 1000.0)
                        time.sleep((wakeup - now) / 1000.0)
                last_restart = ovs.timeval.msec()

                vlog.err("%s, restarting" % status_msg)
                daemon_pid = _fork_and_wait_for_startup()
                if not daemon_pid:
                    break
            else:
                vlog.info("%s, exiting" % status_msg)
                sys.exit(0)

   # Running in new daemon process.


def _close_standard_fds():
    """Close stdin, stdout, stderr.  If we're started from e.g. an SSH session,
    then this keeps us from holding that session open artificially."""
    null_fd = ovs.socket_util.get_null_fd()
    if null_fd >= 0:
        os.dup2(null_fd, 0)
        os.dup2(null_fd, 1)
        os.dup2(null_fd, 2)


def daemonize_start():
    """If daemonization is configured, then starts daemonization, by forking
    and returning in the child process.  The parent process hangs around until
    the child lets it know either that it completed startup successfully (by
    calling daemon_complete()) or that it failed to start up (by exiting with a
    nonzero exit code)."""

    if _detach:
        if _fork_and_wait_for_startup() > 0:
            # Running in parent process.
            sys.exit(0)

        # Running in daemon or monitor process.
        os.setsid()

    if _monitor:
        saved_daemonize_fd = _daemonize_fd
        daemon_pid = _fork_and_wait_for_startup()
        if daemon_pid > 0:
            # Running in monitor process.
            _fork_notify_startup(saved_daemonize_fd)
            _close_standard_fds()
            _monitor_daemon(daemon_pid)
        # Running in daemon process

    if _pidfile:
        _make_pidfile()


def daemonize_complete():
    """If daemonization is configured, then this function notifies the parent
    process that the child process has completed startup successfully."""
    _fork_notify_startup(_daemonize_fd)

    if _detach:
        if _chdir:
            os.chdir("/")
        _close_standard_fds()


def usage():
    sys.stdout.write("""
Daemon options:
   --detach                run in background as daemon
   --no-chdir              do not chdir to '/'
   --pidfile[=FILE]        create pidfile (default: %s/%s.pid)
   --overwrite-pidfile     with --pidfile, start even if already running
""" % (ovs.dirs.RUNDIR, ovs.util.PROGRAM_NAME))


def __read_pidfile(pidfile, delete_if_stale):
    if _pidfile_dev is not None:
        try:
            s = os.stat(pidfile)
            if s.st_ino == _pidfile_ino and s.st_dev == _pidfile_dev:
                # It's our own pidfile.  We can't afford to open it,
                # because closing *any* fd for a file that a process
                # has locked also releases all the locks on that file.
                #
                # Fortunately, we know the associated pid anyhow.
                return os.getpid()
        except OSError:
            pass

    try:
        file_handle = open(pidfile, "r+")
    except IOError, e:
        if e.errno == errno.ENOENT and delete_if_stale:
            return 0
        vlog.warn("%s: open: %s" % (pidfile, e.strerror))
        return -e.errno

    # Python fcntl doesn't directly support F_GETLK so we have to just try
    # to lock it.
    try:
        fcntl.lockf(file_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)

        # pidfile exists but wasn't locked by anyone.  Now we have the lock.
        if not delete_if_stale:
            file_handle.close()
            vlog.warn("%s: pid file is stale" % pidfile)
            return -errno.ESRCH

        # Is the file we have locked still named 'pidfile'?
        try:
            raced = False
            s = os.stat(pidfile)
            s2 = os.fstat(file_handle.fileno())
            if s.st_ino != s2.st_ino or s.st_dev != s2.st_dev:
                raced = True
        except IOError:
            raced = True
        if raced:
            vlog.warn("%s: lost race to delete pidfile" % pidfile)
            return -errno.EALREADY

        # We won the right to delete the stale pidfile.
        try:
            os.unlink(pidfile)
        except IOError, e:
            vlog.warn("%s: failed to delete stale pidfile (%s)"
                            % (pidfile, e.strerror))
            return -e.errno
        else:
            vlog.dbg("%s: deleted stale pidfile" % pidfile)
            file_handle.close()
            return 0
    except IOError, e:
        if e.errno not in [errno.EACCES, errno.EAGAIN]:
            vlog.warn("%s: fcntl: %s" % (pidfile, e.strerror))
            return -e.errno

    # Someone else has the pidfile locked.
    try:
        try:
            error = int(file_handle.readline())
        except IOError, e:
            vlog.warn("%s: read: %s" % (pidfile, e.strerror))
            error = -e.errno
        except ValueError:
            vlog.warn("%s does not contain a pid" % pidfile)
            error = -errno.EINVAL

        return error
    finally:
        try:
            file_handle.close()
        except IOError:
            pass


def read_pidfile(pidfile):
    """Opens and reads a PID from 'pidfile'.  Returns the positive PID if
    successful, otherwise a negative errno value."""
    return __read_pidfile(pidfile, False)


def _check_already_running():
    pid = __read_pidfile(_pidfile, True)
    if pid > 0:
        _fatal("%s: already running as pid %d, aborting" % (_pidfile, pid))
    elif pid < 0:
        _fatal("%s: pidfile check failed (%s), aborting"
               % (_pidfile, os.strerror(pid)))


def add_args(parser):
    """Populates 'parser', an ArgumentParser allocated using the argparse
    module, with the command line arguments required by the daemon module."""

    pidfile = make_pidfile_name(None)

    group = parser.add_argument_group(title="Daemon Options")
    group.add_argument("--detach", action="store_true",
            help="Run in background as a daemon.")
    group.add_argument("--no-chdir", action="store_true",
            help="Do not chdir to '/'.")
    group.add_argument("--monitor", action="store_true",
            help="Monitor %s process." % ovs.util.PROGRAM_NAME)
    group.add_argument("--pidfile", nargs="?", const=pidfile,
            help="Create pidfile (default %s)." % pidfile)
    group.add_argument("--overwrite-pidfile", action="store_true",
            help="With --pidfile, start even if already running.")


def handle_args(args):
    """Handles daemon module settings in 'args'.  'args' is an object
    containing values parsed by the parse_args() method of ArgumentParser.  The
    parent ArgumentParser should have been prepared by add_args() before
    calling parse_args()."""

    if args.detach:
        set_detach()

    if args.no_chdir:
        set_no_chdir()

    if args.pidfile:
        set_pidfile(args.pidfile)

    if args.overwrite_pidfile:
        ignore_existing_pidfile()

    if args.monitor:
        set_monitor()