mdw@git.distorted.org.uk Git - tripe/blob - svc/connect.in

   1 #! @PYTHON@
   2 ### -*-python-*-
   3 ###
   4 ### Connect to remote peers, and keep track of them
   5 ###
   6 ### (c) 2007 Straylight/Edgeware
   7 ###
   8
   9 ###----- Licensing notice ---------------------------------------------------
  10 ###
  11 ### This file is part of Trivial IP Encryption (TrIPE).
  12 ###
  13 ### TrIPE is free software: you can redistribute it and/or modify it under
  14 ### the terms of the GNU General Public License as published by the Free
  15 ### Software Foundation; either version 3 of the License, or (at your
  16 ### option) any later version.
  17 ###
  18 ### TrIPE is distributed in the hope that it will be useful, but WITHOUT
  19 ### ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  20 ### FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  21 ### for more details.
  22 ###
  23 ### You should have received a copy of the GNU General Public License
  24 ### along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  25
  26 VERSION = '@VERSION@'
  27
  28 ###--------------------------------------------------------------------------
  29 ### External dependencies.
  30
  31 from optparse import OptionParser
  32 import tripe as T
  33 import os as OS
  34 import signal as SIG
  35 import errno as E
  36 from math import sqrt
  37 import cdb as CDB
  38 import mLib as M
  39 import re as RX
  40 import sys as SYS
  41 from time import time
  42 import subprocess as PROC
  43
  44 S = T.svcmgr
  45
  46 ###--------------------------------------------------------------------------
  47 ### Running auxiliary commands.
  48
  49 class SelLineQueue (M.SelLineBuffer):
  50   """Glues the select-line-buffer into the coroutine queue system."""
  51
  52   def __new__(cls, file, queue, tag, kind):
  53     """See __init__ for documentation."""
  54     return M.SelLineBuffer.__new__(cls, file.fileno())
  55
  56   def __init__(me, file, queue, tag, kind):
  57     """
  58     Initialize a new line-reading adaptor.
  59
  60     The adaptor reads lines from FILE.  Each line is inserted as a message of
  61     the stated KIND, bearing the TAG, into the QUEUE.  End-of-file is
  62     represented as None.
  63     """
  64     me._q = queue
  65     me._file = file
  66     me._tag = tag
  67     me._kind = kind
  68     me.enable()
  69
  70   @T._callback
  71   def line(me, line):
  72     me._q.put((me._tag, me._kind, line))
  73
  74   @T._callback
  75   def eof(me):
  76     me.disable()
  77     me._q.put((me._tag, me._kind, None))
  78
  79 class ErrorWatch (T.Coroutine):
  80   """
  81   An object which watches stderr streams for errors and converts them into
  82   warnings of the form
  83
  84     WARN connect INFO stderr LINE
  85
  86   The INFO is a list of tokens associated with the file when it was
  87   registered.
  88
  89   Usually there is a single ErrorWatch object, called errorwatch.
  90   """
  91
  92   def __init__(me):
  93     """Initialization: there are no arguments."""
  94     T.Coroutine.__init__(me)
  95     me._q = T.Queue()
  96     me._map = {}
  97     me._seq = 1
  98
  99   def watch(me, file, info):
 100     """
 101     Adds FILE to the collection of files to watch.
 102
 103     INFO will be written in the warning messages from this FILE.  Returns a
 104     sequence number which can be used to unregister the file again.
 105     """
 106     seq = me._seq
 107     me._seq += 1
 108     me._map[seq] = info, SelLineQueue(file, me._q, seq, 'stderr')
 109     return seq
 110
 111   def unwatch(me, seq):
 112     """Stop watching the file with sequence number SEQ."""
 113     del me._map[seq]
 114     return me
 115
 116   def run(me):
 117     """
 118     Coroutine function: read items from the queue and report them.
 119
 120     Unregisters files automatically when they reach EOF.
 121     """
 122     while True:
 123       seq, _, line = me._q.get()
 124       if line is None:
 125         me.unwatch(seq)
 126       else:
 127         S.warn(*['connect'] + me._map[seq][0] + ['stderr', line])
 128
 129 def dbwatch():
 130   """
 131   Coroutine function: wake up every minute and notice changes to the
 132   database.  When a change happens, tell the Pinger (q.v.) to rescan its
 133   peers.
 134   """
 135   cr = T.Coroutine.getcurrent()
 136   main = cr.parent
 137   fw = M.FWatch(opts.cdb)
 138   while True:
 139     timer = M.SelTimer(time() + 60, lambda: cr.switch())
 140     main.switch()
 141     if fw.update():
 142       pinger.rescan(False)
 143       S.notify('connect', 'peerdb-update')
 144
 145 class ChildWatch (M.SelSignal):
 146   """
 147   An object which watches for specified processes exiting and reports
 148   terminations by writing items of the form (TAG, 'exit', RESULT) to a queue.
 149
 150   There is usually only one ChildWatch object, called childwatch.
 151   """
 152
 153   def __new__(cls):
 154     """Initialize the child-watcher."""
 155     return M.SelSignal.__new__(cls, SIG.SIGCHLD)
 156
 157   def __init__(me):
 158     """Initialize the child-watcher."""
 159     me._pid = {}
 160     me.enable()
 161
 162   def watch(me, pid, queue, tag):
 163     """
 164     Register PID as a child to watch.  If it exits, write (TAG, 'exit', CODE)
 165     to the QUEUE, where CODE is one of
 166
 167       * None (successful termination)
 168       * ['exit-nonzero', CODE] (CODE is a string!)
 169       * ['exit-signal', 'S' + CODE] (CODE is the signal number as a string)
 170       * ['exit-unknown', STATUS] (STATUS is the entire exit status, in hex)
 171     """
 172     me._pid[pid] = queue, tag
 173     return me
 174
 175   def unwatch(me, pid):
 176     """Unregister PID as a child to watch."""
 177     del me._pid[pid]
 178     return me
 179
 180   @T._callback
 181   def signalled(me):
 182     """
 183     Called when child processes exit: collect exit statuses and report
 184     failures.
 185     """
 186     while True:
 187       try:
 188         pid, status = OS.waitpid(-1, OS.WNOHANG)
 189       except OSError, exc:
 190         if exc.errno == E.ECHILD:
 191           break
 192       if pid == 0:
 193         break
 194       if pid not in me._pid:
 195         continue
 196       queue, tag = me._pid[pid]
 197       if OS.WIFEXITED(status):
 198         exit = OS.WEXITSTATUS(status)
 199         if exit == 0:
 200           code = None
 201         else:
 202           code = ['exit-nonzero', str(exit)]
 203       elif OS.WIFSIGNALED(status):
 204         code = ['exit-signal', 'S' + str(OS.WTERMSIG(status))]
 205       else:
 206         code = ['exit-unknown', hex(status)]
 207       queue.put((tag, 'exit', code))
 208
 209 class Command (object):
 210   """
 211   Represents a running command.
 212
 213   This class is the main interface to the machery provided by the ChildWatch
 214   and ErrorWatch objects.  See also potwatch.
 215   """
 216
 217   def __init__(me, info, queue, tag, args, env):
 218     """
 219     Start a new child process.
 220
 221     The ARGS are a list of arguments to be given to the child process.  The
 222     ENV is either None or a dictionary of environment variable assignments to
 223     override the extant environment.  INFO is a list of tokens to be included
 224     in warnings about the child's stderr output.  If the child writes a line
 225     to standard output, put (TAG, 'stdout', LINE) to the QUEUE.  When the
 226     child exits, write (TAG, 'exit', CODE) to the QUEUE.
 227     """
 228     me._info = info
 229     me._q = queue
 230     me._tag = tag
 231     myenv = OS.environ.copy()
 232     if env: myenv.update(env)
 233     me._proc = PROC.Popen(args = args, env = myenv, bufsize = 1,
 234                           stdout = PROC.PIPE, stderr = PROC.PIPE)
 235     me._lq = SelLineQueue(me._proc.stdout, queue, tag, 'stdout')
 236     errorwatch.watch(me._proc.stderr, info)
 237     childwatch.watch(me._proc.pid, queue, tag)
 238
 239   def __del__(me):
 240     """
 241     If I've been forgotten then stop watching for termination.
 242     """
 243     childwatch.unwatch(me._proc.pid)
 244
 245 def potwatch(what, name, q):
 246   """
 247   Watch the queue Q for activity as reported by a Command object.
 248
 249   Information from the process's stdout is reported as
 250
 251     NOTE WHAT NAME stdout LINE
 252
 253   abnormal termination is reported as
 254
 255     WARN WHAT NAME CODE
 256
 257   where CODE is what the ChildWatch wrote.
 258   """
 259   eofp = deadp = False
 260   while not deadp or not eofp:
 261     _, kind, more = q.get()
 262     if kind == 'stdout':
 263       if more is None:
 264         eofp = True
 265       else:
 266         S.notify('connect', what, name, 'stdout', more)
 267     elif kind == 'exit':
 268       if more: S.warn('connect', what, name, *more)
 269       deadp = True
 270
 271 ###--------------------------------------------------------------------------
 272 ### Peer database utilities.
 273
 274 _magic = ['_magic']                     # An object distinct from all others
 275
 276 class Peer (object):
 277   """Representation of a peer in the database."""
 278
 279   def __init__(me, peer, cdb = None):
 280     """
 281     Create a new peer, named PEER.
 282
 283     Information about the peer is read from the database CDB, or the default
 284     one given on the command-line.
 285     """
 286     me.name = peer
 287     record = (cdb or CDB.init(opts.cdb))['P' + peer]
 288     me.__dict__.update(M.URLDecode(record, semip = True))
 289
 290   def get(me, key, default = _magic, filter = None):
 291     """
 292     Get the information stashed under KEY from the peer's database record.
 293
 294     If DEFAULT is given, then use it if the database doesn't contain the
 295     necessary information.  If no DEFAULT is given, then report an error.  If
 296     a FILTER function is given then apply it to the information from the
 297     database before returning it.
 298     """
 299     try:
 300       attr = me.__dict__[key]
 301     except KeyError:
 302       if default is _magic:
 303         raise T.TripeJobError('malformed-peer', me.name, 'missing-key', key)
 304       return default
 305     else:
 306       if filter is not None: attr = filter(attr)
 307       return attr
 308
 309   def has(me, key):
 310     """
 311     Return whether the peer's database record has the KEY.
 312     """
 313     return key in me.__dict__
 314
 315   def list(me):
 316     """
 317     Iterate over the available keys in the peer's database record.
 318     """
 319     return me.__dict__.iterkeys()
 320
 321 def boolean(value):
 322   """Parse VALUE as a boolean."""
 323   return value in ['t', 'true', 'y', 'yes', 'on']
 324
 325 ###--------------------------------------------------------------------------
 326 ### Waking up and watching peers.
 327
 328 def run_connect(peer, cmd):
 329   """
 330   Start the job of connecting to the passive PEER.
 331
 332   The CMD string is a shell command which will connect to the peer (via some
 333   back-channel, say ssh and userv), issue a command
 334
 335     SVCSUBMIT connect passive [OPTIONS] USER
 336
 337   and write the resulting challenge to standard error.
 338   """
 339   q = T.Queue()
 340   cmd = Command(['connect', peer.name], q, 'connect',
 341                 ['/bin/sh', '-c', cmd], None)
 342   _, kind, more = q.peek()
 343   if kind == 'stdout':
 344     if more is None:
 345       S.warn('connect', 'connect', peer.name, 'unexpected-eof')
 346     else:
 347       chal = more
 348       S.greet(peer.name, chal)
 349       q.get()
 350   potwatch('connect', peer.name, q)
 351
 352 def run_disconnect(peer, cmd):
 353   """
 354   Start the job of disconnecting from a passive PEER.
 355
 356   The CMD string is a shell command which will disconnect from the peer.
 357   """
 358   q = T.Queue()
 359   cmd = Command(['disconnect', peer.name], q, 'disconnect',
 360                 ['/bin/sh', '-c', cmd], None)
 361   potwatch('disconnect', peer.name, q)
 362
 363 _pingseq = 0
 364 class PingPeer (object):
 365   """
 366   Object representing a peer which we are pinging to ensure that it is still
 367   present.
 368
 369   PingPeer objects are held by the Pinger (q.v.).  The Pinger maintains an
 370   event queue -- which saves us from having an enormous swarm of coroutines
 371   -- but most of the actual work is done here.
 372
 373   In order to avoid confusion between different PingPeer instances for the
 374   same actual peer, each PingPeer has a sequence number (its `seq'
 375   attribute).  Events for the PingPeer are identified by a (PEER, SEQ) pair.
 376   (Using the PingPeer instance itself will prevent garbage collection of
 377   otherwise defunct instances.)
 378   """
 379
 380   def __init__(me, pinger, queue, peer, pingnow):
 381     """
 382     Create a new PingPeer.
 383
 384     The PINGER is the Pinger object we should send the results to.  This is
 385     used when we remove ourselves, if the peer has been explicitly removed.
 386
 387     The QUEUE is the event queue on which timer and ping-command events
 388     should be written.
 389
 390     The PEER is a `Peer' object describing the peer.
 391
 392     If PINGNOW is true, then immediately start pinging the peer.  Otherwise
 393     wait until the usual retry interval.
 394     """
 395     global _pingseq
 396     me._pinger = pinger
 397     me._q = queue
 398     me._peer = peer.name
 399     me.update(peer)
 400     me.seq = _pingseq
 401     _pingseq += 1
 402     me._failures = 0
 403     me._sabotage = False
 404     me._last = '-'
 405     me._nping = 0
 406     me._nlost = 0
 407     me._sigma_t = 0
 408     me._sigma_t2 = 0
 409     me._min = me._max = '-'
 410     now = time()
 411     if pingnow:
 412       me._timer = None
 413       me._ping()
 414     else:
 415       me._timer = M.SelTimer(now + me._every, me._time)
 416
 417   def update(me, peer):
 418     """
 419     Refreshes the timer parameters for this peer.  We don't, however,
 420     immediately reschedule anything: that will happen next time anything
 421     interesting happens.
 422     """
 423     if peer is None: peer = Peer(me._peer)
 424     assert peer.name == me._peer
 425     me._every = peer.get('every', filter = T.timespec, default = 120)
 426     me._timeout = peer.get('timeout', filter = T.timespec, default = 10)
 427     me._retries = peer.get('retries', filter = int, default = 5)
 428     me._connectp = peer.has('connect')
 429     me._knockp = peer.has('knock')
 430     return me
 431
 432   def _ping(me):
 433     """
 434     Send a ping to the peer; the result is sent to the Pinger's event queue.
 435     """
 436     S.rawcommand(T.TripeAsynchronousCommand(
 437       me._q, (me._peer, me.seq),
 438       ['EPING',
 439        '-background', S.bgtag(),
 440        '-timeout', str(me._timeout),
 441        '--',
 442        me._peer]))
 443
 444   def _reconnect(me):
 445     now = time()
 446     try:
 447       peer = Peer(me._peer)
 448       if me._connectp or me._knockp:
 449         S.warn('connect', 'reconnecting', me._peer)
 450         S.forcekx(me._peer, quiet = not me._knockp)
 451         if me._connectp: T.spawn(run_connect, peer, peer.get('connect'))
 452         me._timer = M.SelTimer(now + me._every, me._time)
 453         me._sabotage = False
 454       else:
 455         S.kill(me._peer)
 456     except T.TripeError, e:
 457       if e.args[0] == 'unknown-peer': me._pinger.kill(me._peer)
 458
 459   def event(me, code, stuff):
 460     """
 461     Respond to an event which happened to this peer.
 462
 463     Timer events indicate that we should start a new ping.  (The server has
 464     its own timeout which detects lost packets.)
 465
 466     We trap unknown-peer responses and detach from the Pinger.
 467
 468     If the ping fails and we run out of retries, we attempt to restart the
 469     connection.
 470     """
 471     now = time()
 472     if code == 'TIMER':
 473       me._failures = 0
 474       me._ping()
 475     elif code == 'FAIL':
 476       S.notify('connect', 'ping-failed', me._peer, *stuff)
 477       if not stuff: pass
 478       elif stuff[0] == 'unknown-peer': me._pinger.kill(me._peer)
 479       elif stuff[0] == 'ping-send-failed': me._reconnect()
 480     elif code == 'INFO':
 481       outcome = stuff[0]
 482       if outcome == 'ping-ok' and me._sabotage:
 483         outcome = 'ping-timeout'
 484       if outcome == 'ping-ok':
 485         if me._failures > 0: S.warn('connect', 'ping-ok', me._peer)
 486         t = float(stuff[1])
 487         me._last = '%.1fms' % t
 488         me._sigma_t += t
 489         me._sigma_t2 += t*t
 490         me._nping += 1
 491         if me._min == '-' or t < me._min: me._min = t
 492         if me._max == '-' or t > me._max: me._max = t
 493         me._timer = M.SelTimer(now + me._every, me._time)
 494       elif outcome == 'ping-timeout':
 495         me._failures += 1
 496         me._nlost += 1
 497         S.warn('connect', 'ping-timeout', me._peer,
 498                'attempt', str(me._failures), 'of', str(me._retries))
 499         if me._failures < me._retries:
 500           me._ping()
 501           me._last = 'timeout'
 502         else:
 503           me._reconnect()
 504           me._last = 'reconnect'
 505       elif outcome == 'ping-peer-died':
 506         me._pinger.kill(me._peer)
 507
 508   def sabotage(me):
 509     """Sabotage the peer, for testing purposes."""
 510     me._sabotage = True
 511     if me._timer: me._timer.kill()
 512     T.defer(me._time)
 513
 514   def info(me):
 515     if not me._nping:
 516       mean = sd = min = max = '-'
 517     else:
 518       meanval = me._sigma_t/me._nping
 519       mean = '%.1fms' % meanval
 520       sd = '%.1fms' % sqrt(me._sigma_t2/me._nping - meanval*meanval)
 521       min = '%.1fms' % me._min
 522       max = '%.1fms' % me._max
 523     n = me._nping + me._nlost
 524     if not n: pclost = '-'
 525     else: pclost = '%d' % ((100*me._nlost + n//2)//n)
 526     return { 'last-ping': me._last,
 527              'mean-ping': mean,
 528              'sd-ping': sd,
 529              'n-ping': '%d' % me._nping,
 530              'n-lost': '%d' % me._nlost,
 531              'percent-lost': pclost,
 532              'min-ping': min,
 533              'max-ping': max,
 534              'state': me._timer and 'idle' or 'check',
 535              'failures': str(me._failures) }
 536
 537   @T._callback
 538   def _time(me):
 539     """
 540     Handle timer callbacks by posting a timeout event on the queue.
 541     """
 542     me._timer = None
 543     me._q.put(((me._peer, me.seq), 'TIMER', None))
 544
 545   def __str__(me):
 546     return 'PingPeer(%s, %d, f = %d)' % (me._peer, me.seq, me._failures)
 547   def __repr__(me):
 548     return str(me)
 549
 550 class Pinger (T.Coroutine):
 551   """
 552   The Pinger keeps track of the peers which we expect to be connected and
 553   takes action if they seem to stop responding.
 554
 555   There is usually only one Pinger, called pinger.
 556
 557   The Pinger maintains a collection of PingPeer objects, and an event queue.
 558   The PingPeers direct the results of their pings, and timer events, to the
 559   event queue.  The Pinger's coroutine picks items off the queue and
 560   dispatches them back to the PingPeers as appropriate.
 561   """
 562
 563   def __init__(me):
 564     """Initialize the Pinger."""
 565     T.Coroutine.__init__(me)
 566     me._peers = {}
 567     me._q = T.Queue()
 568
 569   def run(me):
 570     """
 571     Coroutine function: reads the pinger queue and sends events to the
 572     PingPeer objects they correspond to.
 573     """
 574     while True:
 575       (peer, seq), code, stuff = me._q.get()
 576       if peer in me._peers and seq == me._peers[peer].seq:
 577         try: me._peers[peer].event(code, stuff)
 578         except Exception, e:
 579           SYS.excepthook(*SYS.exc_info())
 580
 581   def add(me, peer, pingnow):
 582     """
 583     Add PEER to the collection of peers under the Pinger's watchful eye.
 584     The arguments are as for PingPeer: see above.
 585     """
 586     me._peers[peer.name] = PingPeer(me, me._q, peer, pingnow)
 587     return me
 588
 589   def kill(me, peername):
 590     """Remove PEER from the peers being watched by the Pinger."""
 591     try: del me._peers[peername]
 592     except KeyError: pass
 593     return me
 594
 595   def rescan(me, startup):
 596     """
 597     General resynchronization method.
 598
 599     We scan the list of peers (with connect scripts) known at the server.
 600     Any which are known to the Pinger but aren't known to the server are
 601     removed from our list; newly arrived peers are added.  (Note that a peer
 602     can change state here either due to the server sneakily changing its list
 603     without issuing notifications or, more likely, the database changing its
 604     idea of whether a peer is interesting.)  Finally, PingPeers which are
 605     still present are prodded to update their timing parameters.
 606
 607     This method is called once at startup to pick up the peers already
 608     installed, and again by the dbwatcher coroutine when it detects a change
 609     to the database.
 610     """
 611     if T._debug: print '# rescan peers'
 612     correct = {}
 613     start = {}
 614     for name in S.list():
 615       try: peer = Peer(name)
 616       except KeyError: continue
 617       if peer.get('watch', filter = boolean, default = False):
 618         if T._debug: print '# interesting peer %s' % peer
 619         correct[peer.name] = start[peer.name] = peer
 620       elif startup:
 621         if T._debug: print '# peer %s ready for adoption' % peer
 622         start[peer.name] = peer
 623     for name, obj in me._peers.items():
 624       try:
 625         peer = correct[name]
 626       except KeyError:
 627         if T._debug: print '# peer %s vanished' % name
 628         del me._peers[name]
 629       else:
 630         obj.update(peer)
 631     for name, peer in start.iteritems():
 632       if name in me._peers: continue
 633       if startup:
 634         if T._debug: print '# setting up peer %s' % name
 635         ifname = S.ifname(name)
 636         addr = S.addr(name)
 637         T.defer(adoptpeer, peer, ifname, *addr)
 638       else:
 639         if T._debug: print '# adopting new peer %s' % name
 640         me.add(peer, True)
 641     return me
 642
 643   def adopted(me):
 644     """
 645     Returns the list of peers being watched by the Pinger.
 646     """
 647     return me._peers.keys()
 648
 649   def find(me, name):
 650     """Return the PingPeer with the given name."""
 651     return me._peers[name]
 652
 653 ###--------------------------------------------------------------------------
 654 ### New connections.
 655
 656 def encode_envvars(env, prefix, vars):
 657   """
 658   Encode the variables in VARS suitably for including in a program
 659   environment.  Lowercase letters in variable names are forced to uppercase;
 660   runs of non-alphanumeric characters are replaced by single underscores; and
 661   the PREFIX is prepended.  The resulting variables are written to ENV.
 662   """
 663   for k, v in vars.iteritems():
 664     env[prefix + r_bad.sub('_', k.upper())] = v
 665
 666 r_bad = RX.compile(r'[\W_]+')
 667 def envvars(peer):
 668   """
 669   Translate the database information for a PEER into a dictionary of
 670   environment variables with plausible upper-case names and a P_ prefix.
 671   Also collect the crypto information into A_ variables.
 672   """
 673   env = {}
 674   encode_envvars(env, 'P_', dict([(k, peer.get(k)) for k in peer.list()]))
 675   encode_envvars(env, 'A_', S.algs(peer.name))
 676   return env
 677
 678 def run_ifupdown(what, peer, *args):
 679   """
 680   Run the interface up/down script for a peer.
 681
 682   WHAT is 'ifup' or 'ifdown'.  PEER names the peer in question.  ARGS is a
 683   list of arguments to pass to the script, in addition to the peer name.
 684
 685   The command is run and watched in the background by potwatch.
 686   """
 687   q = T.Queue()
 688   c = Command([what, peer.name], q, what,
 689               M.split(peer.get(what), quotep = True)[0] +
 690               [peer.name] + list(args),
 691               envvars(peer))
 692   potwatch(what, peer.name, q)
 693
 694 def adoptpeer(peer, ifname, *addr):
 695   """
 696   Add a new peer to our collection.
 697
 698   PEER is the `Peer' object; IFNAME is the interface name for its tunnel; and
 699   ADDR is the list of tokens representing its address.
 700
 701   We try to bring up the interface and provoke a connection to the peer if
 702   it's passive.
 703   """
 704   if peer.has('ifup'):
 705     T.Coroutine(run_ifupdown, name = 'ifup %s' % peer.name) \
 706         .switch('ifup', peer, ifname, *addr)
 707   cmd = peer.get('connect', default = None)
 708   if cmd is not None:
 709     T.Coroutine(run_connect, name = 'connect %s' % peer.name) \
 710         .switch(peer, cmd)
 711   if peer.get('watch', filter = boolean, default = False):
 712     pinger.add(peer, False)
 713
 714 def disownpeer(peer):
 715   """Drop the PEER from the Pinger and put its interface to bed."""
 716   try: pinger.kill(peer)
 717   except KeyError: pass
 718   cmd = peer.get('disconnect', default = None)
 719   if cmd is not None:
 720     T.Coroutine(run_disconnect, name = 'disconnect %s' % peer.name) \
 721         .switch(peer, cmd)
 722   if peer.has('ifdown'):
 723     T.Coroutine(run_ifupdown, name = 'ifdown %s' % peer.name) \
 724         .switch('ifdown', peer)
 725
 726 def addpeer(peer, addr, ephemp):
 727   """
 728   Process a connect request from a new peer PEER on address ADDR.
 729
 730   Any existing peer with this name is disconnected from the server.  EPHEMP
 731   is the default ephemeral-ness state for the new peer.
 732   """
 733   if peer.name in S.list():
 734     S.kill(peer.name)
 735   try:
 736     S.add(peer.name,
 737           tunnel = peer.get('tunnel', default = None),
 738           keepalive = peer.get('keepalive', default = None),
 739           key = peer.get('key', default = None),
 740           priv = peer.get('priv', default = None),
 741           mobile = peer.get('mobile', filter = boolean, default = False),
 742           knock = peer.get('knock', default = None),
 743           cork = peer.get('cork', filter = boolean, default = False),
 744           ephemeral = peer.get('ephemeral', filter = boolean,
 745                                default = ephemp),
 746           *addr)
 747   except T.TripeError, exc:
 748     raise T.TripeJobError(*exc.args)
 749
 750 ## Dictionary mapping challenges to waiting passive-connection coroutines.
 751 chalmap = {}
 752
 753 def notify(_, code, *rest):
 754   """
 755   Watch for notifications.
 756
 757   We trap ADD and KILL notifications, and send them straight to adoptpeer and
 758   disownpeer respectively; and dispatch GREET notifications to the
 759   corresponding waiting coroutine.
 760   """
 761   if code == 'ADD':
 762     try: p = Peer(rest[0])
 763     except KeyError: pass
 764     else: adoptpeer(p, *rest[1:])
 765   elif code == 'KILL':
 766     try: p = Peer(rest[0])
 767     except KeyError: pass
 768     else: disownpeer(p, *rest[1:])
 769   elif code == 'GREET':
 770     chal = rest[0]
 771     try: cr = chalmap[chal]
 772     except KeyError: pass
 773     else: cr.switch(rest[1:])
 774   elif code == 'KNOCK':
 775     try: p = Peer(rest[0])
 776     except KeyError:
 777       S.warn(['connect', 'knock-unknown-peer', rest[0]])
 778       return
 779     if p.get('peer') != 'PASSIVE':
 780       S.warn(['connect', 'knock-active-peer', p.name])
 781       return
 782     dot = p.name.find('.')
 783     if dot >= 0: kname = p.name[dot + 1:]
 784     else: kname = p.name
 785     ktag = p.get('key', p.name)
 786     if kname != ktag:
 787       S.warn(['connect', 'knock-tag-mismatch',
 788               'peer', pname, 'public-key-tag', ktag])
 789       return
 790     T.spawn(addpeer, p, rest[1:], True)
 791
 792 ###--------------------------------------------------------------------------
 793 ### Command implementation.
 794
 795 def cmd_kick(name):
 796   """
 797   kick NAME: Force a new connection attempt for the NAMEd peer.
 798   """
 799   try: pp = pinger.find(name)
 800   except KeyError: raise T.TripeJobError('peer-not-adopted', name)
 801   try: peer = Peer(name)
 802   except KeyError: raise T.TripeJobError('unknown-peer', name)
 803   conn = peer.get('connect', None)
 804   if conn: T.spawn(run_connect, peer, peer.get('connect'))
 805   else: T.spawn(lambda p: S.forcekx(p.name), peer)
 806
 807 def cmd_adopted():
 808   """
 809   adopted: Report a list of adopted peers.
 810   """
 811   for name in pinger.adopted():
 812     T.svcinfo(name)
 813
 814 def cmd_active(name):
 815   """
 816   active NAME: Handle an active connection request for the peer called NAME.
 817
 818   The appropriate address is read from the database automatically.
 819   """
 820   try: peer = Peer(name)
 821   except KeyError: raise T.TripeJobError('unknown-peer', name)
 822   addr = peer.get('peer')
 823   if addr == 'PASSIVE':
 824     raise T.TripeJobError('passive-peer', name)
 825   addpeer(peer, M.split(addr, quotep = True)[0], True)
 826
 827 def cmd_listactive():
 828   """
 829   list: Report a list of the available active peers.
 830   """
 831   cdb = CDB.init(opts.cdb)
 832   for key in cdb.keys():
 833     if key.startswith('P') and Peer(key[1:]).get('peer', '') != 'PASSIVE':
 834       T.svcinfo(key[1:])
 835
 836 def cmd_info(name):
 837   """
 838   info NAME: Report the database entries for the named peer.
 839   """
 840   try: peer = Peer(name)
 841   except KeyError: raise T.TripeJobError('unknown-peer', name)
 842   d = {}
 843   try: pp = pinger.find(name)
 844   except KeyError: pass
 845   else: d.update(pp.info())
 846   items = list(peer.list()) + d.keys()
 847   items.sort()
 848   for i in items:
 849     try: v = d[i]
 850     except KeyError: v = peer.get(i)
 851     T.svcinfo('%s=%s' % (i, v.replace('\n', ' ')))
 852
 853 def cmd_userpeer(user):
 854   """
 855   userpeer USER: Report the peer name for the named user.
 856   """
 857   try: name = CDB.init(opts.cdb)['U' + user]
 858   except KeyError: raise T.TripeJobError('unknown-user', user)
 859   T.svcinfo(name)
 860
 861 def cmd_passive(*args):
 862   """
 863   passive [OPTIONS] USER: Await the arrival of the named USER.
 864
 865   Report a challenge; when (and if!) the server receives a greeting quoting
 866   this challenge, add the corresponding peer to the server.
 867   """
 868   now = time()
 869   timeout = 30
 870   op = T.OptParse(args, ['-timeout'])
 871   for opt in op:
 872     if opt == '-timeout':
 873       timeout = T.timespec(op.arg())
 874   user, = op.rest(1, 1)
 875   try: name = CDB.init(opts.cdb)['U' + user]
 876   except KeyError: raise T.TripeJobError('unknown-user', user)
 877   try: peer = Peer(name)
 878   except KeyError: raise T.TripeJobError('unknown-peer', name)
 879   chal = S.getchal()
 880   cr = T.Coroutine.getcurrent()
 881   timer = M.SelTimer(now + timeout, lambda: cr.switch(None))
 882   try:
 883     T.svcinfo(chal)
 884     chalmap[chal] = cr
 885     addr = cr.parent.switch()
 886     if addr is None:
 887       raise T.TripeJobError('connect-timeout')
 888     addpeer(peer, addr, True)
 889   finally:
 890     del chalmap[chal]
 891
 892 def cmd_sabotage(name):
 893   """
 894   sabotage NAME: Sabotage the NAMEd peer so that we think it can't be pinged.
 895   """
 896   try: pp = pinger.find(name)
 897   except KeyError: raise T.TripeJobError('unknown-peer', name)
 898   pp.sabotage()
 899
 900 ###--------------------------------------------------------------------------
 901 ### Start up.
 902
 903 def setup():
 904   """
 905   Service setup.
 906
 907   Register the notification watcher, rescan the peers, and add automatic
 908   active peers.
 909   """
 910   S.handler['NOTE'] = notify
 911   S.watch('+n')
 912
 913   pinger.rescan(opts.startup)
 914
 915   if opts.startup:
 916     cdb = CDB.init(opts.cdb)
 917     try:
 918       autos = cdb['%AUTO']
 919     except KeyError:
 920       autos = ''
 921     for name in M.split(autos)[0]:
 922       try:
 923         peer = Peer(name, cdb)
 924         addpeer(peer, M.split(peer.get('peer'), quotep = True)[0], False)
 925       except T.TripeJobError, err:
 926         S.warn('connect', 'auto-add-failed', name, *err.args)
 927
 928 def init():
 929   """
 930   Initialization to be done before service startup.
 931   """
 932   global errorwatch, childwatch, pinger
 933   errorwatch = ErrorWatch()
 934   childwatch = ChildWatch()
 935   pinger = Pinger()
 936   T.Coroutine(dbwatch, name = 'dbwatch').switch()
 937   errorwatch.switch()
 938   pinger.switch()
 939
 940 def parse_options():
 941   """
 942   Parse the command-line options.
 943
 944   Automatically changes directory to the requested configdir, and turns on
 945   debugging.  Returns the options object.
 946   """
 947   op = OptionParser(usage = '%prog [-a FILE] [-d DIR]',
 948                     version = '%%prog %s' % VERSION)
 949
 950   op.add_option('-a', '--admin-socket',
 951                 metavar = 'FILE', dest = 'tripesock', default = T.tripesock,
 952                 help = 'Select socket to connect to [default %default]')
 953   op.add_option('-d', '--directory',
 954                 metavar = 'DIR', dest = 'dir', default = T.configdir,
 955                 help = 'Select current diretory [default %default]')
 956   op.add_option('-p', '--peerdb',
 957                 metavar = 'FILE', dest = 'cdb', default = T.peerdb,
 958                 help = 'Select peers database [default %default]')
 959   op.add_option('--daemon', dest = 'daemon',
 960                 default = False, action = 'store_true',
 961                 help = 'Become a daemon after successful initialization')
 962   op.add_option('--debug', dest = 'debug',
 963                 default = False, action = 'store_true',
 964                 help = 'Emit debugging trace information')
 965   op.add_option('--startup', dest = 'startup',
 966                 default = False, action = 'store_true',
 967                 help = 'Being called as part of the server startup')
 968
 969   opts, args = op.parse_args()
 970   if args: op.error('no arguments permitted')
 971   OS.chdir(opts.dir)
 972   T._debug = opts.debug
 973   return opts
 974
 975 ## Service table, for running manually.
 976 service_info = [('connect', VERSION, {
 977   'adopted': (0, 0, '', cmd_adopted),
 978   'kick': (1, 1, 'PEER', cmd_kick),
 979   'passive': (1, None, '[OPTIONS] USER', cmd_passive),
 980   'active': (1, 1, 'PEER', cmd_active),
 981   'info': (1, 1, 'PEER', cmd_info),
 982   'list-active': (0, 0, '', cmd_listactive),
 983   'userpeer': (1, 1, 'USER', cmd_userpeer),
 984   'sabotage': (1, 1, 'PEER', cmd_sabotage)
 985 })]
 986
 987 if __name__ == '__main__':
 988   opts = parse_options()
 989   OS.environ['TRIPESOCK'] = opts.tripesock
 990   T.runservices(opts.tripesock, service_info,
 991                 init = init, setup = setup,
 992                 daemon = opts.daemon)
 993
 994 ###----- That's all, folks --------------------------------------------------