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))
218 upness, reason = _kick.get()
220 ## Make sure the configuration file is up-to-date. Don't worry if we
221 ## can't do anything useful.
224 except Exception, exc:
225 SM.warn('conntrack', 'config-file-error',
226 exc.__class__.__name__, str(exc))
228 ## Find the current list of peers.
231 ## Work out the primary IP address.
233 addr = localaddr(CF.testaddr)
239 ## Now decide what to do.
241 for g, pp in CF.groups:
243 ## Find out which peer in the group ought to be active.
247 for t, p, a, m in pp:
248 if p is None or not upness:
252 if upness and ip is None and \
253 ipq is not None and (ipq & m) == a:
255 if t == 'down' or t.startswith('down/'):
263 ## Shut down the wrong ones.
266 what = map.get(p, 'leave')
273 except T.TripeError, exc:
274 if exc.args[0] == 'unknown-peer':
275 ## Inherently racy; don't worry about this.
281 ## Start the right one if necessary.
282 if want is not None and not found:
285 SM.svcsubmit('connect', 'active', want)
286 except T.TripeError, exc:
287 SM.warn('conntrack', 'connect-failed', want, *exc.args)
290 ## Commit the changes.
292 SM.notify('conntrack', upness and 'up' or 'down', *reason)
293 for c in changes: c()
295 def netupdown(upness, reason):
297 Add or kill peers according to whether the network is up or down.
299 UPNESS is true if the network is up, or false if it's down.
302 _kick.put((upness, reason))
304 ###--------------------------------------------------------------------------
305 ### NetworkManager monitor.
307 NM_NAME = 'org.freedesktop.NetworkManager'
308 NM_PATH = '/org/freedesktop/NetworkManager'
310 NMCA_IFACE = NM_NAME + '.Connection.Active'
312 NM_STATE_CONNECTED = 3
314 class NetworkManagerMonitor (object):
316 Watch NetworkManager signals for changes in network state.
319 ## Strategy. There are two kinds of interesting state transitions for us.
320 ## The first one is the global are-we-connected state, which we'll use to
321 ## toggle network upness on a global level. The second is which connection
322 ## has the default route, which we'll use to tweak which peer in the peer
323 ## group is active. The former is most easily tracked using the signal
324 ## org.freedesktop.NetworkManager.StateChanged; for the latter, we track
325 ## org.freedesktop.NetworkManager.Connection.Active.PropertiesChanged and
326 ## look for when a new connection gains the default route.
330 nm = bus.get_object(NM_NAME, NM_PATH)
331 state = nm.Get(NM_IFACE, 'State')
332 if state == NM_STATE_CONNECTED:
333 netupdown(True, ['nm', 'initially-connected'])
335 netupdown(False, ['nm', 'initially-disconnected'])
336 except D.DBusException:
338 bus.add_signal_receiver(me._nm_state, 'StateChanged', NM_IFACE,
340 bus.add_signal_receiver(me._nm_connchange,
341 'PropertiesChanged', NMCA_IFACE,
344 def _nm_state(me, state):
345 if state == NM_STATE_CONNECTED:
346 netupdown(True, ['nm', 'connected'])
348 netupdown(False, ['nm', 'disconnected'])
350 def _nm_connchange(me, props):
351 if props.get('Default', False):
352 netupdown(True, ['nm', 'default-connection-change'])
354 ###--------------------------------------------------------------------------
357 ICD_NAME = 'com.nokia.icd'
358 ICD_PATH = '/com/nokia/icd'
361 class MaemoICdMonitor (object):
363 Watch ICd signals for changes in network state.
366 ## Strategy. ICd only handles one connection at a time in steady state,
367 ## though when switching between connections, it tries to bring the new one
368 ## up before shutting down the old one. This makes life a bit easier than
369 ## it is with NetworkManager. On the other hand, the notifications are
370 ## relative to particular connections only, and the indicator that the old
371 ## connection is down (`IDLE') comes /after/ the new one comes up
372 ## (`CONNECTED'), so we have to remember which one is active.
376 icd = bus.get_object(ICD_NAME, ICD_PATH)
378 iap = icd.get_ipinfo(dbus_interface = ICD_IFACE)[0]
380 netupdown(True, ['icd', 'initially-connected', iap])
381 except D.DBusException:
383 netupdown(False, ['icd', 'initially-disconnected'])
384 except D.DBusException:
386 bus.add_signal_receiver(me._icd_state, 'status_changed', ICD_IFACE,
389 def _icd_state(me, iap, ty, state, hunoz):
390 if state == 'CONNECTED':
392 netupdown(True, ['icd', 'connected', iap])
393 elif state == 'IDLE' and iap == me._iap:
395 netupdown(False, ['icd', 'idle'])
397 ###--------------------------------------------------------------------------
398 ### D-Bus connection tracking.
400 class DBusMonitor (object):
402 Maintains a connection to the system D-Bus, and watches for signals.
404 If the connection is initially down, or drops for some reason, we retry
405 periodically (every five seconds at the moment). If the connection
406 resurfaces, we reattach the monitors.
411 Initialise the object and try to establish a connection to the bus.
414 me._loop = D.mainloop.glib.DBusGMainLoop()
415 me._state = 'startup'
420 Add a monitor object to watch for signals.
422 MON.attach(BUS) is called, with BUS being the connection to the system
423 bus. MON should query its service's current status and watch for
427 if me._bus is not None:
430 def _reconnect(me, hunoz = None):
432 Start connecting to the bus.
434 If we fail the first time, retry periodically.
436 if me._state == 'startup':
437 T.aside(SM.notify, 'conntrack', 'dbus-connection', 'startup')
438 elif me._state == 'connected':
439 T.aside(SM.notify, 'conntrack', 'dbus-connection', 'lost')
441 T.aside(SM.notify, 'conntrack', 'dbus-connection',
442 'state=%s' % me._state)
443 me._state == 'reconnecting'
445 if me._try_connect():
446 G.timeout_add_seconds(5, me._try_connect)
448 def _try_connect(me):
450 Actually make a connection attempt.
452 If we succeed, attach the monitors.
455 addr = OS.getenv('TRIPE_CONNTRACK_BUS')
456 if addr == 'SESSION':
457 bus = D.SessionBus(mainloop = me._loop, private = True)
458 elif addr is not None:
459 bus = D.bus.BusConnection(addr, mainloop = me._loop)
461 bus = D.SystemBus(mainloop = me._loop, private = True)
464 except D.DBusException, e:
467 me._state = 'connected'
468 bus.call_on_disconnection(me._reconnect)
469 T.aside(SM.notify, 'conntrack', 'dbus-connection', 'connected')
472 ###--------------------------------------------------------------------------
475 class GIOWatcher (object):
477 Monitor I/O events using glib.
479 def __init__(me, conn, mc = G.main_context_default()):
483 def connected(me, sock):
484 me._watch = G.io_add_watch(sock, G.IO_IN,
485 lambda *hunoz: me._conn.receive())
486 def disconnected(me):
487 G.source_remove(me._watch)
490 me._mc.iteration(True)
492 SM.iowatch = GIOWatcher(SM)
496 Service initialization.
498 Add the D-Bus monitor here, because we might send commands off immediately,
499 and we want to make sure the server connection is up.
502 T.Coroutine(kickpeers, name = 'kickpeers').switch()
504 DBM.addmon(NetworkManagerMonitor())
505 DBM.addmon(MaemoICdMonitor())
506 G.timeout_add_seconds(30, lambda: (netupdown(True, ['interval-timer'])
511 Parse the command-line options.
513 Automatically changes directory to the requested configdir, and turns on
514 debugging. Returns the options object.
516 op = OptionParser(usage = '%prog [-a FILE] [-d DIR]',
517 version = '%%prog %s' % VERSION)
519 op.add_option('-a', '--admin-socket',
520 metavar = 'FILE', dest = 'tripesock', default = T.tripesock,
521 help = 'Select socket to connect to [default %default]')
522 op.add_option('-d', '--directory',
523 metavar = 'DIR', dest = 'dir', default = T.configdir,
524 help = 'Select current diretory [default %default]')
525 op.add_option('-c', '--config',
526 metavar = 'FILE', dest = 'conf', default = 'conntrack.conf',
527 help = 'Select configuration [default %default]')
528 op.add_option('--daemon', dest = 'daemon',
529 default = False, action = 'store_true',
530 help = 'Become a daemon after successful initialization')
531 op.add_option('--debug', dest = 'debug',
532 default = False, action = 'store_true',
533 help = 'Emit debugging trace information')
534 op.add_option('--startup', dest = 'startup',
535 default = False, action = 'store_true',
536 help = 'Being called as part of the server startup')
538 opts, args = op.parse_args()
539 if args: op.error('no arguments permitted')
541 T._debug = opts.debug
544 ## Service table, for running manually.
545 def cmd_updown(upness):
546 return lambda *args: T.defer(netupdown, upness, ['manual'] + list(args))
547 service_info = [('conntrack', VERSION, {
548 'up': (0, None, '', cmd_updown(True)),
549 'down': (0, None, '', cmd_updown(False))
552 if __name__ == '__main__':
553 opts = parse_options()
554 CF = Config(opts.conf)
555 T.runservices(opts.tripesock, service_info,
556 init = init, daemon = opts.daemon)
558 ###----- That's all, folks --------------------------------------------------