4 ### Service for automatically tracking network connection status
6 ### (c) 2010 Straylight/Edgeware
9 ###----- Licensing notice ---------------------------------------------------
11 ### This file is part of Trivial IP Encryption (TrIPE).
13 ### TrIPE is free software; you can redistribute it and/or modify
14 ### it under the terms of the GNU General Public License as published by
15 ### the Free Software Foundation; either version 2 of the License, or
16 ### (at your option) any later version.
18 ### TrIPE is distributed in the hope that it will be useful,
19 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ### GNU General Public License for more details.
23 ### You should have received a copy of the GNU General Public License
24 ### along with TrIPE; if not, write to the Free Software Foundation,
25 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 ###--------------------------------------------------------------------------
30 ### External dependencies.
32 from ConfigParser import RawConfigParser
33 from optparse import OptionParser
40 for i in ['mainloop', 'mainloop.glib']:
41 __import__('dbus.%s' % i)
43 from struct import pack, unpack
46 ##__import__('rmcr').__debug = True
48 ###--------------------------------------------------------------------------
51 class struct (object):
52 """A simple container object."""
53 def __init__(me, **kw):
54 me.__dict__.update(kw)
56 def toposort(cmp, things):
58 Generate the THINGS in an order consistent with a given partial order.
60 The function CMP(X, Y) should return true if X must precede Y, and false if
61 it doesn't care. If X and Y are equal then it should return false.
63 The THINGS may be any finite iterable; it is converted to a list
67 ## Make sure we can index the THINGS, and prepare an ordering table.
68 ## What's going on? The THINGS might not have a helpful equality
69 ## predicate, so it's easier to work with indices. The ordering table will
70 ## remember which THINGS (by index) are considered greater than other
74 order = [{} for i in xrange(n)]
75 rorder = [{} for i in xrange(n)]
78 if i != j and cmp(things[i], things[j]):
82 ## Now we can do the sort.
87 if order[i] is not None:
89 if len(order[i]) == 0:
97 ###--------------------------------------------------------------------------
98 ### Parse the configuration file.
100 ## Hmm. Should I try to integrate this with the peers database? It's not a
101 ## good fit; it'd need special hacks in tripe-newpeers. And the use case for
102 ## this service are largely going to be satellite notes, I don't think
103 ## scalability's going to be a problem.
105 class Config (object):
107 Represents a configuration file.
109 The most interesting thing is probably the `groups' slot, which stores a
110 list of pairs (NAME, PATTERNS); the NAME is a string, and the PATTERNS a
111 list of (TAG, PEER, ADDR, MASK) triples. The implication is that there
112 should be precisely one peer with a name matching NAME-*, and that it
113 should be NAME-TAG, where (TAG, PEER, ADDR, MASK) is the first triple such
114 that the host's primary IP address (if PEER is None -- or the IP address it
115 would use for communicating with PEER) is within the network defined by
119 def __init__(me, file):
121 Construct a new Config object, reading the given FILE.
124 me._fwatch = M.FWatch(file)
129 See whether the configuration file has been updated.
131 if me._fwatch.update():
136 Internal function to update the configuration from the underlying file.
139 ## Read the configuration. We have no need of the fancy substitutions,
140 ## so turn them all off.
141 cp = RawConfigParser()
144 ## Save the test address. Make sure it's vaguely sensible. The default
145 ## is probably good for most cases, in fact, since that address isn't
146 ## actually in use. Note that we never send packets to the test address;
147 ## we just use it to discover routing information.
148 if cp.has_option('DEFAULT', 'test-addr'):
149 testaddr = cp.get('DEFAULT', 'test-addr')
150 S.inet_aton(testaddr)
154 ## Scan the configuration file and build the groups structure.
156 for sec in cp.sections():
158 for tag in cp.options(sec):
159 spec = cp.get(sec, tag).split()
161 ## Parse the entry into peer and network.
168 ## Syntax of a net is ADDRESS/MASK, where ADDRESS is a dotted-quad,
169 ## and MASK is either a dotted-quad or a single integer N indicating
170 ## a mask with N leading ones followed by trailing zeroes.
171 slash = net.index('/')
172 addr, = unpack('>L', S.inet_aton(net[:slash]))
173 if net.find('.', slash + 1) >= 0:
174 mask, = unpack('>L', S.inet_aton(net[:slash]))
176 n = int(net[slash + 1:], 10)
177 mask = (1 << 32) - (1 << 32 - n)
178 pats.append((tag, peer, addr & mask, mask))
180 ## Annoyingly, RawConfigParser doesn't preserve the order of options.
181 ## In order to make things vaguely sane, we topologically sort the
182 ## patterns so that more specific patterns are checked first.
183 pats = list(toposort(lambda (t, p, a, m), (tt, pp, aa, mm): \
185 (p == pp and m == (m | mm) and aa == (a & mm)),
187 groups.append((sec, pats))
190 me.testaddr = testaddr
193 ### This will be a configuration file.
196 ###--------------------------------------------------------------------------
197 ### Responding to a network up/down event.
201 Return the local IP address used for talking to PEER.
203 sk = S.socket(S.AF_INET, S.SOCK_DGRAM)
206 sk.connect((peer, 1))
207 addr, _ = sk.getsockname()
208 addr, = unpack('>L', S.inet_aton(addr))
219 upness, reason = _kick.get()
221 ## Make sure the configuration file is up-to-date. Don't worry if we
222 ## can't do anything useful.
225 except Exception, exc:
226 SM.warn('conntrack', 'config-file-error',
227 exc.__class__.__name__, str(exc))
229 ## Find the current list of peers.
232 ## Work out the primary IP address.
234 addr = localaddr(CF.testaddr)
240 ## Now decide what to do.
242 for g, pp in CF.groups:
244 ## Find out which peer in the group ought to be active.
248 for t, p, a, m in pp:
249 if p is None or not upness:
253 if upness and ip is None and \
254 ipq is not None and (ipq & m) == a:
261 ## Shut down the wrong ones.
264 what = map.get(p, 'leave')
271 except T.TripeError, exc:
272 if exc.args[0] == 'unknown-peer':
273 ## Inherently racy; don't worry about this.
279 ## Start the right one if necessary.
280 if want is not None and (not found or ip != lastip.get(g, None)):
283 SM.svcsubmit('connect', 'active', want)
284 except T.TripeError, exc:
285 SM.warn('conntrack', 'connect-failed', want, *exc.args)
289 ## Commit the changes.
291 SM.notify('conntrack', upness and 'up' or 'down', *reason)
292 for c in changes: c()
294 def netupdown(upness, reason):
296 Add or kill peers according to whether the network is up or down.
298 UPNESS is true if the network is up, or false if it's down.
301 _kick.put((upness, reason))
303 ###--------------------------------------------------------------------------
304 ### NetworkManager monitor.
306 NM_NAME = 'org.freedesktop.NetworkManager'
307 NM_PATH = '/org/freedesktop/NetworkManager'
309 NMCA_IFACE = NM_NAME + '.Connection.Active'
311 NM_STATE_CONNECTED = 3
313 class NetworkManagerMonitor (object):
315 Watch NetworkManager signals for changes in network state.
318 ## Strategy. There are two kinds of interesting state transitions for us.
319 ## The first one is the global are-we-connected state, which we'll use to
320 ## toggle network upness on a global level. The second is which connection
321 ## has the default route, which we'll use to tweak which peer in the peer
322 ## group is active. The former is most easily tracked using the signal
323 ## org.freedesktop.NetworkManager.StateChanged; for the latter, we track
324 ## org.freedesktop.NetworkManager.Connection.Active.PropertiesChanged and
325 ## look for when a new connection gains the default route.
329 nm = bus.get_object(NM_NAME, NM_PATH)
330 state = nm.Get(NM_IFACE, 'State')
331 if state == NM_STATE_CONNECTED:
332 netupdown(True, ['nm', 'initially-connected'])
334 netupdown(False, ['nm', 'initially-disconnected'])
335 except D.DBusException:
337 bus.add_signal_receiver(me._nm_state, 'StateChanged', NM_IFACE,
339 bus.add_signal_receiver(me._nm_connchange,
340 'PropertiesChanged', NMCA_IFACE,
343 def _nm_state(me, state):
344 if state == NM_STATE_CONNECTED:
345 netupdown(True, ['nm', 'connected'])
347 netupdown(False, ['nm', 'disconnected'])
349 def _nm_connchange(me, props):
350 if props.get('Default', False):
351 netupdown(True, ['nm', 'default-connection-change'])
353 ###--------------------------------------------------------------------------
356 ICD_NAME = 'com.nokia.icd'
357 ICD_PATH = '/com/nokia/icd'
360 class MaemoICdMonitor (object):
362 Watch ICd signals for changes in network state.
365 ## Strategy. ICd only handles one connection at a time in steady state,
366 ## though when switching between connections, it tries to bring the new one
367 ## up before shutting down the old one. This makes life a bit easier than
368 ## it is with NetworkManager. On the other hand, the notifications are
369 ## relative to particular connections only, and the indicator that the old
370 ## connection is down (`IDLE') comes /after/ the new one comes up
371 ## (`CONNECTED'), so we have to remember which one is active.
375 icd = bus.get_object(ICD_NAME, ICD_PATH)
377 iap = icd.get_ipinfo(dbus_interface = ICD_IFACE)[0]
379 netupdown(True, ['icd', 'initially-connected', iap])
380 except D.DBusException:
382 netupdown(False, ['icd', 'initially-disconnected'])
383 except D.DBusException:
385 bus.add_signal_receiver(me._icd_state, 'status_changed', ICD_IFACE,
388 def _icd_state(me, iap, ty, state, hunoz):
389 if state == 'CONNECTED':
391 netupdown(True, ['icd', 'connected', iap])
392 elif state == 'IDLE' and iap == me._iap:
394 netupdown(False, ['icd', 'idle'])
396 ###--------------------------------------------------------------------------
397 ### D-Bus connection tracking.
399 class DBusMonitor (object):
401 Maintains a connection to the system D-Bus, and watches for signals.
403 If the connection is initially down, or drops for some reason, we retry
404 periodically (every five seconds at the moment). If the connection
405 resurfaces, we reattach the monitors.
410 Initialise the object and try to establish a connection to the bus.
413 me._loop = D.mainloop.glib.DBusGMainLoop()
414 me._state = 'startup'
419 Add a monitor object to watch for signals.
421 MON.attach(BUS) is called, with BUS being the connection to the system
422 bus. MON should query its service's current status and watch for
426 if me._bus is not None:
429 def _reconnect(me, hunoz = None):
431 Start connecting to the bus.
433 If we fail the first time, retry periodically.
435 if me._state == 'startup':
436 T.aside(SM.notify, 'conntrack', 'dbus-connection', 'startup')
437 elif me._state == 'connected':
438 T.aside(SM.notify, 'conntrack', 'dbus-connection', 'lost')
440 T.aside(SM.notify, 'conntrack', 'dbus-connection',
441 'state=%s' % me._state)
442 me._state == 'reconnecting'
444 if me._try_connect():
445 G.timeout_add_seconds(5, me._try_connect)
447 def _try_connect(me):
449 Actually make a connection attempt.
451 If we succeed, attach the monitors.
454 addr = OS.getenv('TRIPE_CONNTRACK_BUS')
455 if addr == 'SESSION':
456 bus = D.SessionBus(mainloop = me._loop, private = True)
457 elif addr is not None:
458 bus = D.bus.BusConnection(addr, mainloop = me._loop)
460 bus = D.SystemBus(mainloop = me._loop, private = True)
463 except D.DBusException, e:
466 me._state = 'connected'
467 bus.call_on_disconnection(me._reconnect)
468 T.aside(SM.notify, 'conntrack', 'dbus-connection', 'connected')
471 ###--------------------------------------------------------------------------
474 class GIOWatcher (object):
476 Monitor I/O events using glib.
478 def __init__(me, conn, mc = G.main_context_default()):
482 def connected(me, sock):
483 me._watch = G.io_add_watch(sock, G.IO_IN,
484 lambda *hunoz: me._conn.receive())
485 def disconnected(me):
486 G.source_remove(me._watch)
489 me._mc.iteration(True)
491 SM.iowatch = GIOWatcher(SM)
495 Service initialization.
497 Add the D-Bus monitor here, because we might send commands off immediately,
498 and we want to make sure the server connection is up.
501 T.Coroutine(kickpeers, name = 'kickpeers').switch()
503 DBM.addmon(NetworkManagerMonitor())
504 DBM.addmon(MaemoICdMonitor())
505 G.timeout_add_seconds(30, lambda: (netupdown(True, ['interval-timer'])
510 Parse the command-line options.
512 Automatically changes directory to the requested configdir, and turns on
513 debugging. Returns the options object.
515 op = OptionParser(usage = '%prog [-a FILE] [-d DIR]',
516 version = '%%prog %s' % VERSION)
518 op.add_option('-a', '--admin-socket',
519 metavar = 'FILE', dest = 'tripesock', default = T.tripesock,
520 help = 'Select socket to connect to [default %default]')
521 op.add_option('-d', '--directory',
522 metavar = 'DIR', dest = 'dir', default = T.configdir,
523 help = 'Select current diretory [default %default]')
524 op.add_option('-c', '--config',
525 metavar = 'FILE', dest = 'conf', default = 'conntrack.conf',
526 help = 'Select configuration [default %default]')
527 op.add_option('--daemon', dest = 'daemon',
528 default = False, action = 'store_true',
529 help = 'Become a daemon after successful initialization')
530 op.add_option('--debug', dest = 'debug',
531 default = False, action = 'store_true',
532 help = 'Emit debugging trace information')
533 op.add_option('--startup', dest = 'startup',
534 default = False, action = 'store_true',
535 help = 'Being called as part of the server startup')
537 opts, args = op.parse_args()
538 if args: op.error('no arguments permitted')
540 T._debug = opts.debug
543 ## Service table, for running manually.
544 def cmd_updown(upness):
545 return lambda *args: T.defer(netupdown, upness, ['manual'] + list(args))
546 service_info = [('conntrack', VERSION, {
547 'up': (0, None, '', cmd_updown(True)),
548 'down': (0, None, '', cmd_updown(False))
551 if __name__ == '__main__':
552 opts = parse_options()
553 CF = Config(opts.conf)
554 T.runservices(opts.tripesock, service_info,
555 init = init, daemon = opts.daemon)
557 ###----- That's all, folks --------------------------------------------------