/mandos/trunk

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/trunk

« back to all changes in this revision

Viewing changes to mandos-ctl

  • Committer: Teddy Hogeborn
  • Date: 2015-05-23 20:18:34 UTC
  • mto: This revision was merged to the branch mainline in revision 756.
  • Revision ID: teddy@recompile.se-20150523201834-e89ex4ito93yni8x
mandos: Use multiprocessing module to run checkers.

For a long time, the Mandos server has occasionally logged the message
"ERROR: Child process vanished".  This was never a fatal error, but it
has been annoying and slightly worrying, since a definite cause was
not found.  One potential cause could be the "multiprocessing" and
"subprocess" modules conflicting w.r.t. SIGCHLD.  To avoid this,
change the running of checkers from using subprocess.Popen
asynchronously to instead first create a multiprocessing.Process()
(which is asynchronous) calling a function, and have that function
then call subprocess.call() (which is synchronous).  In this way, the
only thing using any asynchronous subprocesses is the multiprocessing
module.

This makes it necessary to change one small thing in the D-Bus API,
since the subprocesses.call() function does not expose the raw wait(2)
status value.

DBUS-API (CheckerCompleted): Change the second value provided by this
                             D-Bus signal from the raw wait(2) status
                             to the actual terminating signal number.
mandos (subprocess_call_pipe): New function to be called by
                               multiprocessing.Process (starting a
                               separate process).
(Client.last_checker signal): New attribute for signal which
                              terminated last checker.  Like
                              last_checker_status, only not accessible
                              via D-Bus.
(Client.checker_callback): Take new "connection" argument and use it
                           to get returncode; set last_checker_signal.
                           Return False so gobject does not call this
                           callback again.
(Client.start_checker): Start checker using a multiprocessing.Process
                        instead of a subprocess.Popen.
(ClientDBus.checker_callback): Take new "connection" argument.        Call
                               Client.checker_callback early to have
                               it set last_checker_status and
                               last_checker_signal; use those.  Change
                               second value provided to D-Bus signal
                               CheckerCompleted to use
                               last_checker_signal if checker was
                               terminated by signal.
mandos-monitor: Update to reflect DBus API change.
(MandosClientWidget.checker_completed): Take "signal" instead of
                                        "condition" argument.  Use it
                                        accordingly.  Remove dead code
                                        (os.WCOREDUMP case).

Show diffs side-by-side

added added

removed removed

Lines of Context:
75
75
version = "1.6.9"
76
76
 
77
77
 
78
 
try:
79
 
    dbus.OBJECT_MANAGER_IFACE
80
 
except AttributeError:
81
 
    dbus.OBJECT_MANAGER_IFACE = "org.freedesktop.DBus.ObjectManager"
82
 
 
83
78
def milliseconds_to_string(ms):
84
79
    td = datetime.timedelta(0, 0, 0, ms)
85
80
    return ("{days}{hours:02}:{minutes:02}:{seconds:02}".format(
116
111
    # avoid excessive use of external libraries.
117
112
    
118
113
    # New type for defining tokens, syntax, and semantics all-in-one
119
 
    Token = collections.namedtuple("Token", (
120
 
        "regexp",  # To match token; if "value" is not None, must have
121
 
                   # a "group" containing digits
122
 
        "value",   # datetime.timedelta or None
123
 
        "followers"))           # Tokens valid after this token
 
114
    Token = collections.namedtuple("Token",
 
115
                                   ("regexp", # To match token; if
 
116
                                              # "value" is not None,
 
117
                                              # must have a "group"
 
118
                                              # containing digits
 
119
                                    "value",  # datetime.timedelta or
 
120
                                              # None
 
121
                                    "followers")) # Tokens valid after
 
122
                                                  # this token
124
123
    # RFC 3339 "duration" tokens, syntax, and semantics; taken from
125
124
    # the "duration" ABNF definition in RFC 3339, Appendix A.
126
125
    token_end = Token(re.compile(r"$"), None, frozenset())
179
178
                break
180
179
        else:
181
180
            # No currently valid tokens were found
182
 
            raise ValueError("Invalid RFC 3339 duration: {!r}"
183
 
                             .format(duration))
 
181
            raise ValueError("Invalid RFC 3339 duration")
184
182
    # End token found
185
183
    return value
186
184
 
188
186
def string_to_delta(interval):
189
187
    """Parse a string and return a datetime.timedelta
190
188
    
191
 
    >>> string_to_delta('7d')
 
189
    >>> string_to_delta("7d")
192
190
    datetime.timedelta(7)
193
 
    >>> string_to_delta('60s')
 
191
    >>> string_to_delta("60s")
194
192
    datetime.timedelta(0, 60)
195
 
    >>> string_to_delta('60m')
 
193
    >>> string_to_delta("60m")
196
194
    datetime.timedelta(0, 3600)
197
 
    >>> string_to_delta('24h')
 
195
    >>> string_to_delta("24h")
198
196
    datetime.timedelta(1)
199
 
    >>> string_to_delta('1w')
 
197
    >>> string_to_delta("1w")
200
198
    datetime.timedelta(7)
201
 
    >>> string_to_delta('5m 30s')
 
199
    >>> string_to_delta("5m 30s")
202
200
    datetime.timedelta(0, 330)
203
201
    """
204
202
    
346
344
    
347
345
    mandos_serv = dbus.Interface(mandos_dbus_objc,
348
346
                                 dbus_interface = server_interface)
349
 
    mandos_serv_object_manager = dbus.Interface(
350
 
        mandos_dbus_objc, dbus_interface = dbus.OBJECT_MANAGER_IFACE)
351
347
    
352
348
    #block stderr since dbus library prints to stderr
353
349
    null = os.open(os.path.devnull, os.O_RDWR)
356
352
    os.close(null)
357
353
    try:
358
354
        try:
359
 
            mandos_clients = { path: ifs_and_props[client_interface]
360
 
                               for path, ifs_and_props in
361
 
                               mandos_serv_object_manager
362
 
                               .GetManagedObjects().items()
363
 
                               if client_interface in ifs_and_props }
 
355
            mandos_clients = mandos_serv.GetAllClientsWithProperties()
364
356
        finally:
365
357
            #restore stderr
366
358
            os.dup2(stderrcopy, sys.stderr.fileno())
367
359
            os.close(stderrcopy)
368
 
    except dbus.exceptions.DBusException as e:
369
 
        print("Access denied: Accessing mandos server through D-Bus: {}"
370
 
              .format(e), file=sys.stderr)
 
360
    except dbus.exceptions.DBusException:
 
361
        print("Access denied: Accessing mandos server through dbus.",
 
362
              file=sys.stderr)
371
363
        sys.exit(1)
372
364
    
373
365
    # Compile dict of (clients: properties) to process