| 1 | #! @PYTHON@ |
| 2 | ### -*-python-*- |
| 3 | ### |
| 4 | ### Watch arrival and departure of peers |
| 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 |
| 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. |
| 17 | ### |
| 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. |
| 22 | ### |
| 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. |
| 26 | |
| 27 | VERSION = '@VERSION@' |
| 28 | |
| 29 | ###-------------------------------------------------------------------------- |
| 30 | ### External dependencies. |
| 31 | |
| 32 | from optparse import OptionParser |
| 33 | import tripe as T |
| 34 | import os as OS |
| 35 | import signal as SIG |
| 36 | import errno as E |
| 37 | import cdb as CDB |
| 38 | import mLib as M |
| 39 | import re as RX |
| 40 | from time import time |
| 41 | import subprocess as PROC |
| 42 | |
| 43 | S = T.svcmgr |
| 44 | |
| 45 | ###-------------------------------------------------------------------------- |
| 46 | ### Running auxiliary commands. |
| 47 | |
| 48 | class SelLineQueue (M.SelLineBuffer): |
| 49 | """Glues the select-line-buffer into the coroutine queue system.""" |
| 50 | |
| 51 | def __new__(cls, file, queue, tag, kind): |
| 52 | """See __init__ for documentation.""" |
| 53 | return M.SelLineBuffer.__new__(cls, file.fileno()) |
| 54 | |
| 55 | def __init__(me, file, queue, tag, kind): |
| 56 | """ |
| 57 | Initialize a new line-reading adaptor. |
| 58 | |
| 59 | The adaptor reads lines from FILE. Each line is inserted as a message of |
| 60 | the stated KIND, bearing the TAG, into the QUEUE. End-of-file is |
| 61 | represented as None. |
| 62 | """ |
| 63 | me._q = queue |
| 64 | me._file = file |
| 65 | me._tag = tag |
| 66 | me._kind = kind |
| 67 | me.enable() |
| 68 | |
| 69 | @T._callback |
| 70 | def line(me, line): |
| 71 | me._q.put((me._tag, me._kind, line)) |
| 72 | |
| 73 | @T._callback |
| 74 | def eof(me): |
| 75 | me.disable() |
| 76 | me._q.put((me._tag, me._kind, None)) |
| 77 | |
| 78 | class ErrorWatch (T.Coroutine): |
| 79 | """ |
| 80 | An object which watches stderr streams for errors and converts them into |
| 81 | warnings of the form |
| 82 | |
| 83 | WARN watch INFO stderr LINE |
| 84 | |
| 85 | The INFO is a list of tokens associated with the file when it was |
| 86 | registered. |
| 87 | |
| 88 | Usually there is a single ErrorWatch object, called errorwatch. |
| 89 | """ |
| 90 | |
| 91 | def __init__(me): |
| 92 | """Initialization: there are no arguments.""" |
| 93 | T.Coroutine.__init__(me) |
| 94 | me._q = T.Queue() |
| 95 | me._map = {} |
| 96 | me._seq = 1 |
| 97 | |
| 98 | def watch(me, file, info): |
| 99 | """ |
| 100 | Adds FILE to the collection of files to watch. |
| 101 | |
| 102 | INFO will be written in the warning messages from this FILE. Returns a |
| 103 | sequence number which can be used to unregister the file again. |
| 104 | """ |
| 105 | seq = me._seq |
| 106 | me._seq += 1 |
| 107 | me._map[seq] = info, SelLineQueue(file, me._q, seq, 'stderr') |
| 108 | return seq |
| 109 | |
| 110 | def unwatch(me, seq): |
| 111 | """Stop watching the file with sequence number SEQ.""" |
| 112 | del me._map[seq] |
| 113 | return me |
| 114 | |
| 115 | def run(me): |
| 116 | """ |
| 117 | Coroutine function: read items from the queue and report them. |
| 118 | |
| 119 | Unregisters files automatically when they reach EOF. |
| 120 | """ |
| 121 | while True: |
| 122 | seq, _, line = me._q.get() |
| 123 | if line is None: |
| 124 | me.unwatch(seq) |
| 125 | else: |
| 126 | S.warn(*['watch'] + me._map[seq][0] + ['stderr', line]) |
| 127 | |
| 128 | def dbwatch(): |
| 129 | """ |
| 130 | Coroutine function: wake up every second and notice changes to the |
| 131 | database. When a change happens, tell the Pinger (q.v.) to rescan its |
| 132 | peers. |
| 133 | """ |
| 134 | cr = T.Coroutine.getcurrent() |
| 135 | main = cr.parent |
| 136 | fw = M.FWatch(opts.cdb) |
| 137 | while True: |
| 138 | timer = M.SelTimer(time() + 1, lambda: cr.switch()) |
| 139 | main.switch() |
| 140 | if fw.update(): |
| 141 | pinger.rescan(False) |
| 142 | S.notify('watch', 'peerdb-update') |
| 143 | |
| 144 | class ChildWatch (M.SelSignal): |
| 145 | """ |
| 146 | An object which watches for specified processes exiting and reports |
| 147 | terminations by writing items of the form (TAG, 'exit', RESULT) to a queue. |
| 148 | |
| 149 | There is usually only one ChildWatch object, called childwatch. |
| 150 | """ |
| 151 | |
| 152 | def __new__(cls): |
| 153 | """Initialize the child-watcher.""" |
| 154 | return M.SelSignal.__new__(cls, SIG.SIGCHLD) |
| 155 | |
| 156 | def __init__(me): |
| 157 | """Initialize the child-watcher.""" |
| 158 | me._pid = {} |
| 159 | me.enable() |
| 160 | |
| 161 | def watch(me, pid, queue, tag): |
| 162 | """ |
| 163 | Register PID as a child to watch. If it exits, write (TAG, 'exit', CODE) |
| 164 | to the QUEUE, where CODE is one of |
| 165 | |
| 166 | * None (successful termination) |
| 167 | * ['exit-nonzero', CODE] (CODE is a string!) |
| 168 | * ['exit-signal', 'S' + CODE] (CODE is the signal number as a string) |
| 169 | * ['exit-unknown', STATUS] (STATUS is the entire exit status, in hex) |
| 170 | """ |
| 171 | me._pid[pid] = queue, tag |
| 172 | return me |
| 173 | |
| 174 | def unwatch(me, pid): |
| 175 | """Unregister PID as a child to watch.""" |
| 176 | del me._pid[pid] |
| 177 | return me |
| 178 | |
| 179 | @T._callback |
| 180 | def signalled(me): |
| 181 | """ |
| 182 | Called when child processes exit: collect exit statuses and report |
| 183 | failures. |
| 184 | """ |
| 185 | while True: |
| 186 | try: |
| 187 | pid, status = OS.waitpid(-1, OS.WNOHANG) |
| 188 | except OSError, exc: |
| 189 | if exc.errno == E.ECHILD: |
| 190 | break |
| 191 | if pid == 0: |
| 192 | break |
| 193 | if pid not in me._pid: |
| 194 | continue |
| 195 | queue, tag = me._pid[pid] |
| 196 | if OS.WIFEXITED(status): |
| 197 | exit = OS.WEXITSTATUS(status) |
| 198 | if exit == 0: |
| 199 | code = None |
| 200 | else: |
| 201 | code = ['exit-nonzero', str(exit)] |
| 202 | elif OS.WIFSIGNALED(status): |
| 203 | code = ['exit-signal', 'S' + str(OS.WTERMSIG(status))] |
| 204 | else: |
| 205 | code = ['exit-unknown', hex(status)] |
| 206 | queue.put((tag, 'exit', code)) |
| 207 | |
| 208 | class Command (object): |
| 209 | """ |
| 210 | Represents a running command. |
| 211 | |
| 212 | This class is the main interface to the machery provided by the ChildWatch |
| 213 | and ErrorWatch objects. See also potwatch. |
| 214 | """ |
| 215 | |
| 216 | def __init__(me, info, queue, tag, args, env): |
| 217 | """ |
| 218 | Start a new child process. |
| 219 | |
| 220 | The ARGS are a list of arguments to be given to the child process. The |
| 221 | ENV is either None or a dictionary of environment variable assignments to |
| 222 | override the extant environment. INFO is a list of tokens to be included |
| 223 | in warnings about the child's stderr output. If the child writes a line |
| 224 | to standard output, put (TAG, 'stdout', LINE) to the QUEUE. When the |
| 225 | child exits, write (TAG, 'exit', CODE) to the QUEUE. |
| 226 | """ |
| 227 | me._info = info |
| 228 | me._q = queue |
| 229 | me._tag = tag |
| 230 | myenv = OS.environ.copy() |
| 231 | if env: myenv.update(env) |
| 232 | me._proc = PROC.Popen(args = args, env = myenv, bufsize = 1, |
| 233 | stdout = PROC.PIPE, stderr = PROC.PIPE) |
| 234 | me._lq = SelLineQueue(me._proc.stdout, queue, tag, 'stdout') |
| 235 | errorwatch.watch(me._proc.stderr, info) |
| 236 | childwatch.watch(me._proc.pid, queue, tag) |
| 237 | |
| 238 | def __del__(me): |
| 239 | """ |
| 240 | If I've been forgotten then stop watching for termination. |
| 241 | """ |
| 242 | childwatch.unwatch(me._proc.pid) |
| 243 | |
| 244 | def potwatch(what, name, q): |
| 245 | """ |
| 246 | Watch the queue Q for activity as reported by a Command object. |
| 247 | |
| 248 | Information from the process's stdout is reported as |
| 249 | |
| 250 | NOTE WHAT NAME stdout LINE |
| 251 | |
| 252 | abnormal termination is reported as |
| 253 | |
| 254 | WARN WHAT NAME CODE |
| 255 | |
| 256 | where CODE is what the ChildWatch wrote. |
| 257 | """ |
| 258 | eofp = deadp = False |
| 259 | while not deadp or not eofp: |
| 260 | _, kind, more = q.get() |
| 261 | if kind == 'stdout': |
| 262 | if more is None: |
| 263 | eofp = True |
| 264 | else: |
| 265 | S.notify('watch', what, name, 'stdout', more) |
| 266 | elif kind == 'exit': |
| 267 | if more: S.warn('watch', what, name, *more) |
| 268 | deadp = True |
| 269 | |
| 270 | ###-------------------------------------------------------------------------- |
| 271 | ### Peer database utilities. |
| 272 | |
| 273 | def timespec(info, key, default): |
| 274 | """Parse INFO[KEY] as a timespec, or return DEFAULT.""" |
| 275 | try: |
| 276 | return T.timespec(info[key]) |
| 277 | except (KeyError, T.TripeJobError): |
| 278 | return default |
| 279 | |
| 280 | def integer(info, key, default): |
| 281 | """Parse INFO[KEY] as an integer, or return DEFAULT.""" |
| 282 | try: |
| 283 | return int(info[key]) |
| 284 | except (KeyError, ValueError): |
| 285 | return default |
| 286 | |
| 287 | def boolean(info, key, default): |
| 288 | """Parse INFO[KEY] as a boolean, or return DEFAULT.""" |
| 289 | try: |
| 290 | return info[key] in ['t', 'true', 'y', 'yes', 'on'] |
| 291 | except (KeyError, ValueError): |
| 292 | return default |
| 293 | |
| 294 | def peerinfo(peer): |
| 295 | """ |
| 296 | Return a dictionary containing information about PEER from the database. |
| 297 | """ |
| 298 | return dict(M.URLDecode(CDB.init(opts.cdb)['P' + peer], semip = True)) |
| 299 | |
| 300 | ###-------------------------------------------------------------------------- |
| 301 | ### Waking up and watching peers. |
| 302 | |
| 303 | def connect(peer, conn = None): |
| 304 | """ |
| 305 | Start the job of connecting to the passive PEER. |
| 306 | |
| 307 | The CONN string is a shell command which will connect to the peer (via some |
| 308 | back-channel, say ssh and userv), issue a command |
| 309 | |
| 310 | SVCSUBMIT connect passive [OPTIONS] USER |
| 311 | |
| 312 | and write the resulting challenge to standard error. |
| 313 | """ |
| 314 | if conn is None: |
| 315 | try: |
| 316 | conn = peerinfo(peer)['connect'] |
| 317 | except KeyError: |
| 318 | return |
| 319 | q = T.Queue() |
| 320 | cmd = Command(['connect', peer], q, 'connect', |
| 321 | ['/bin/sh', '-c', conn], None) |
| 322 | _, kind, more = q.peek() |
| 323 | if kind == 'stdout': |
| 324 | if more is None: |
| 325 | S.warn('watch', 'connect', peer, 'unexpected-eof') |
| 326 | else: |
| 327 | chal = more |
| 328 | S.greet(peer, chal) |
| 329 | q.get() |
| 330 | potwatch('connect', peer, q) |
| 331 | |
| 332 | _pingseq = 0 |
| 333 | class PingPeer (object): |
| 334 | """ |
| 335 | Object representing a peer which we are pinging to ensure that it is still |
| 336 | present. |
| 337 | |
| 338 | PingPeer objects are held by the Pinger (q.v.). The Pinger maintains an |
| 339 | event queue -- which saves us from having an enormous swarm of coroutines |
| 340 | -- but most of the actual work is done here. |
| 341 | |
| 342 | In order to avoid confusion between different PingPeer instances for the |
| 343 | same actual peer, each PingPeer has a sequence number (its `seq' |
| 344 | attribute). Events for the PingPeer are identified by a (PEER, SEQ) pair. |
| 345 | (Using the PingPeer instance itself will prevent garbage collection of |
| 346 | otherwise defunct instances.) |
| 347 | """ |
| 348 | |
| 349 | def __init__(me, pinger, queue, peer, info, pingnow): |
| 350 | """ |
| 351 | Create a new PingPeer. |
| 352 | |
| 353 | The PINGER is the Pinger object we should send the results to. This is |
| 354 | used when we remove ourselves, if the peer has been explicitly removed. |
| 355 | |
| 356 | The QUEUE is the event queue on which timer and ping-command events |
| 357 | should be written. |
| 358 | |
| 359 | The PEER is just the peer's name, as a string. |
| 360 | |
| 361 | The INFO is the database record for the peer, as a dictionary, or None if |
| 362 | it's not readily available. (This is just a tweak to save multiple |
| 363 | probes if we don't really need them.) |
| 364 | |
| 365 | If PINGNOW is true, then immediately start pinging the peer. Otherwise |
| 366 | wait until the usual retry interval. |
| 367 | """ |
| 368 | global _pingseq |
| 369 | me._pinger = pinger |
| 370 | me._q = queue |
| 371 | me._peer = peer |
| 372 | me.update(info) |
| 373 | me.seq = _pingseq |
| 374 | _pingseq += 1 |
| 375 | me._failures = 0 |
| 376 | if pingnow: |
| 377 | me._timer = None |
| 378 | me._ping() |
| 379 | else: |
| 380 | me._timer = M.SelTimer(time() + me._every, me._time) |
| 381 | |
| 382 | def update(me, info): |
| 383 | """ |
| 384 | Refreshes the timer parameters for this peer. We don't, however, |
| 385 | immediately reschedule anything: that will happen next time anything |
| 386 | interesting happens. |
| 387 | """ |
| 388 | if info is None: |
| 389 | info = peerinfo(me._peer) |
| 390 | me._every = timespec(info, 'every', 120) |
| 391 | me._timeout = timespec(info, 'timeout', 10) |
| 392 | me._retries = integer(info, 'retries', 5) |
| 393 | me._connectp = 'connect' in info |
| 394 | return me |
| 395 | |
| 396 | def _ping(me): |
| 397 | """ |
| 398 | Send a ping to the peer; the result is sent to the Pinger's event queue. |
| 399 | """ |
| 400 | S.rawcommand(T.TripeAsynchronousCommand( |
| 401 | me._q, (me._peer, me.seq), |
| 402 | ['EPING', |
| 403 | '-background', S.bgtag(), |
| 404 | '-timeout', str(me._timeout), |
| 405 | '--', |
| 406 | me._peer])) |
| 407 | |
| 408 | def _reconnect(me): |
| 409 | info = peerinfo(me._peer) |
| 410 | if 'connect' in info: |
| 411 | S.warn('watch', 'reconnecting', me._peer) |
| 412 | S.forcekx(me._peer) |
| 413 | T.spawn(connect, me._peer) |
| 414 | me._timer = M.SelTimer(time() + me._every, me._time) |
| 415 | else: |
| 416 | S.kill(me._peer) |
| 417 | |
| 418 | def event(me, code, stuff): |
| 419 | """ |
| 420 | Respond to an event which happened to this peer. |
| 421 | |
| 422 | Timer events indicate that we should start a new ping. (The server has |
| 423 | its own timeout which detects lost packets.) |
| 424 | |
| 425 | We trap unknown-peer responses and detach from the Pinger. |
| 426 | |
| 427 | If the ping fails and we run out of retries, we attempt to restart the |
| 428 | connection. |
| 429 | """ |
| 430 | if code == 'TIMER': |
| 431 | me._failures = 0 |
| 432 | me._ping() |
| 433 | elif code == 'FAIL': |
| 434 | S.notify('watch', 'ping-failed', me._peer, *stuff) |
| 435 | if not stuff: |
| 436 | pass |
| 437 | elif stuff[0] == 'unknown-peer': |
| 438 | me._pinger.kill(me._peer) |
| 439 | elif stuff[0] == 'ping-send-failed': |
| 440 | me._reconnect() |
| 441 | elif code == 'INFO': |
| 442 | if stuff[0] == 'ping-ok': |
| 443 | if me._failures > 0: |
| 444 | S.warn('watch', 'ping-ok', me._peer) |
| 445 | me._timer = M.SelTimer(time() + me._every, me._time) |
| 446 | elif stuff[0] == 'ping-timeout': |
| 447 | me._failures += 1 |
| 448 | S.warn('watch', 'ping-timeout', me._peer, |
| 449 | 'attempt', str(me._failures), 'of', str(me._retries)) |
| 450 | if me._failures < me._retries: |
| 451 | me._ping() |
| 452 | else: |
| 453 | me._reconnect() |
| 454 | elif stuff[0] == 'ping-peer-died': |
| 455 | me._pinger.kill(me._peer) |
| 456 | |
| 457 | @T._callback |
| 458 | def _time(me): |
| 459 | """ |
| 460 | Handle timer callbacks by posting a timeout event on the queue. |
| 461 | """ |
| 462 | me._timer = None |
| 463 | me._q.put(((me._peer, me.seq), 'TIMER', None)) |
| 464 | |
| 465 | def __str__(me): |
| 466 | return 'PingPeer(%s, %d, f = %d)' % (me._peer, me.seq, me._failures) |
| 467 | def __repr__(me): |
| 468 | return str(me) |
| 469 | |
| 470 | class Pinger (T.Coroutine): |
| 471 | """ |
| 472 | The Pinger keeps track of the peers which we expect to be connected and |
| 473 | takes action if they seem to stop responding. |
| 474 | |
| 475 | There is usually only one Pinger, called pinger. |
| 476 | |
| 477 | The Pinger maintains a collection of PingPeer objects, and an event queue. |
| 478 | The PingPeers direct the results of their pings, and timer events, to the |
| 479 | event queue. The Pinger's coroutine picks items off the queue and |
| 480 | dispatches them back to the PingPeers as appropriate. |
| 481 | """ |
| 482 | |
| 483 | def __init__(me): |
| 484 | """Initialize the Pinger.""" |
| 485 | T.Coroutine.__init__(me) |
| 486 | me._peers = {} |
| 487 | me._q = T.Queue() |
| 488 | |
| 489 | def run(me): |
| 490 | """ |
| 491 | Coroutine function: reads the pinger queue and sends events to the |
| 492 | PingPeer objects they correspond to. |
| 493 | """ |
| 494 | while True: |
| 495 | (peer, seq), code, stuff = me._q.get() |
| 496 | if peer in me._peers and seq == me._peers[peer].seq: |
| 497 | me._peers[peer].event(code, stuff) |
| 498 | |
| 499 | def add(me, peer, info, pingnow): |
| 500 | """ |
| 501 | Add PEER to the collection of peers under the Pinger's watchful eye. |
| 502 | The arguments are as for PingPeer: see above. |
| 503 | """ |
| 504 | me._peers[peer] = PingPeer(me, me._q, peer, info, pingnow) |
| 505 | return me |
| 506 | |
| 507 | def kill(me, peer): |
| 508 | """Remove PEER from the peers being watched by the Pinger.""" |
| 509 | del me._peers[peer] |
| 510 | return me |
| 511 | |
| 512 | def rescan(me, startup): |
| 513 | """ |
| 514 | General resynchronization method. |
| 515 | |
| 516 | We scan the list of peers (with connect scripts) known at the server. |
| 517 | Any which are known to the Pinger but aren't known to the server are |
| 518 | removed from our list; newly arrived peers are added. (Note that a peer |
| 519 | can change state here either due to the server sneakily changing its list |
| 520 | without issuing notifications or, more likely, the database changing its |
| 521 | idea of whether a peer is interesting.) Finally, PingPeers which are |
| 522 | still present are prodded to update their timing parameters. |
| 523 | |
| 524 | This method is called once at startup to pick up the peers already |
| 525 | installed, and again by the dbwatcher coroutine when it detects a change |
| 526 | to the database. |
| 527 | """ |
| 528 | correct = {} |
| 529 | for peer in S.list(): |
| 530 | try: |
| 531 | info = peerinfo(peer) |
| 532 | except KeyError: |
| 533 | continue |
| 534 | if boolean(info, 'watch', False): |
| 535 | correct[peer] = info |
| 536 | for peer, obj in me._peers.items(): |
| 537 | if peer in correct: |
| 538 | obj.update(correct[peer]) |
| 539 | else: |
| 540 | del me._peers[peer] |
| 541 | for peer, info in correct.iteritems(): |
| 542 | if peer not in me._peers: |
| 543 | if startup: |
| 544 | ifname = S.ifname(peer) |
| 545 | addr = S.addr(peer) |
| 546 | T.defer(addpeer, info, peer, ifname, *addr) |
| 547 | else: |
| 548 | me.add(peer, info, True) |
| 549 | return me |
| 550 | |
| 551 | def adopted(me): |
| 552 | """ |
| 553 | Returns the list of peers being watched by the Pinger. |
| 554 | """ |
| 555 | return me._peers.keys() |
| 556 | |
| 557 | ###-------------------------------------------------------------------------- |
| 558 | ### New connections. |
| 559 | |
| 560 | def encode_envvars(env, prefix, vars): |
| 561 | """ |
| 562 | Encode the variables in VARS suitably for including in a program |
| 563 | environment. Lowercase letters in variable names are forced to uppercase; |
| 564 | runs of non-alphanumeric characters are replaced by single underscores; and |
| 565 | the PREFIX is prepended. The resulting variables are written to ENV. |
| 566 | """ |
| 567 | for k, v in vars.iteritems(): |
| 568 | env[prefix + r_bad.sub('_', k.upper())] = v |
| 569 | |
| 570 | r_bad = RX.compile(r'[\W_]+') |
| 571 | def envvars(info): |
| 572 | """ |
| 573 | Translate the database INFO dictionary for a peer into a dictionary of |
| 574 | environment variables with plausible upper-case names and a P_ prefix. |
| 575 | Also collect the crypto information into A_ variables. |
| 576 | """ |
| 577 | env = {} |
| 578 | encode_envvars(env, 'P_', info) |
| 579 | encode_envvars(env, 'A_', S.algs()) |
| 580 | return env |
| 581 | |
| 582 | def ifupdown(what, peer, info, *args): |
| 583 | """ |
| 584 | Run the interface up/down script for a peer. |
| 585 | |
| 586 | WHAT is 'ifup' or 'ifdown'. PEER names the peer in question. INFO is the |
| 587 | database record dictionary. ARGS is a list of arguments to pass to the |
| 588 | script, in addition to the peer name. |
| 589 | |
| 590 | The command is run and watched in the background by potwatch. |
| 591 | """ |
| 592 | q = T.Queue() |
| 593 | c = Command([what, peer], q, what, |
| 594 | M.split(info[what], quotep = True)[0] + |
| 595 | [peer] + list(args), |
| 596 | envvars(info)) |
| 597 | potwatch(what, peer, q) |
| 598 | |
| 599 | def addpeer(info, peer, ifname, *addr): |
| 600 | """ |
| 601 | Add a new peer to our collection. |
| 602 | |
| 603 | INFO is the peer information dictionary, or None if we don't have one yet. |
| 604 | |
| 605 | PEER names the peer; IFNAME is the interface name for its tunnel; and ADDR |
| 606 | is the list of tokens representing its address. |
| 607 | |
| 608 | We try to bring up the interface and provoke a connection to the peer if |
| 609 | it's passive. |
| 610 | """ |
| 611 | if info is None: |
| 612 | try: |
| 613 | info = peerinfo(peer) |
| 614 | except KeyError: |
| 615 | return |
| 616 | if 'ifup' in info: |
| 617 | T.Coroutine(ifupdown, name = 'ifup %s' % peer) \ |
| 618 | .switch('ifup', peer, info, ifname, *addr) |
| 619 | if 'connect' in info: |
| 620 | T.Coroutine(connect, name = 'connect %s' % peer) \ |
| 621 | .switch(peer, info['connect']) |
| 622 | if boolean(info, 'watch', False): |
| 623 | pinger.add(peer, info, False) |
| 624 | |
| 625 | def delpeer(peer): |
| 626 | """Drop the PEER from the Pinger and put its interface to bed.""" |
| 627 | try: |
| 628 | info = peerinfo(peer) |
| 629 | except KeyError: |
| 630 | return |
| 631 | try: |
| 632 | pinger.kill(peer) |
| 633 | except KeyError: |
| 634 | pass |
| 635 | if 'ifdown' in info: |
| 636 | T.Coroutine(ifupdown, name = 'ifdown %s' % peer) \ |
| 637 | .switch('ifdown', peer, info) |
| 638 | |
| 639 | def notify(_, code, *rest): |
| 640 | """ |
| 641 | Watch for notifications. |
| 642 | |
| 643 | We trap ADD and KILL notifications, and send them straight to addpeer and |
| 644 | delpeer respectively. |
| 645 | """ |
| 646 | if code == 'ADD': |
| 647 | addpeer(None, *rest) |
| 648 | elif code == 'KILL': |
| 649 | delpeer(*rest) |
| 650 | |
| 651 | ###-------------------------------------------------------------------------- |
| 652 | ### Command stubs. |
| 653 | |
| 654 | def cmd_stub(*args): |
| 655 | raise T.TripeJobError('not-implemented') |
| 656 | |
| 657 | def cmd_kick(peer): |
| 658 | """ |
| 659 | kick PEER: Force a new connection attempt for PEER |
| 660 | """ |
| 661 | if peer not in pinger.adopted(): |
| 662 | raise T.TripeJobError('peer-not-adopted', peer) |
| 663 | T.spawn(connect, peer) |
| 664 | |
| 665 | def cmd_adopted(): |
| 666 | """ |
| 667 | adopted: Report a list of adopted peers. |
| 668 | """ |
| 669 | for peer in pinger.adopted(): |
| 670 | T.svcinfo(peer) |
| 671 | |
| 672 | ###-------------------------------------------------------------------------- |
| 673 | ### Start up. |
| 674 | |
| 675 | def setup(): |
| 676 | """ |
| 677 | Service setup. |
| 678 | |
| 679 | Register the notification watcher, and rescan the peers. |
| 680 | """ |
| 681 | S.handler['NOTE'] = notify |
| 682 | S.watch('+n') |
| 683 | pinger.rescan(opts.startup) |
| 684 | |
| 685 | def init(): |
| 686 | """ |
| 687 | Initialization to be done before service startup. |
| 688 | """ |
| 689 | global errorwatch, childwatch, pinger |
| 690 | errorwatch = ErrorWatch() |
| 691 | childwatch = ChildWatch() |
| 692 | pinger = Pinger() |
| 693 | T.Coroutine(dbwatch, name = 'dbwatch').switch() |
| 694 | errorwatch.switch() |
| 695 | pinger.switch() |
| 696 | |
| 697 | def parse_options(): |
| 698 | """ |
| 699 | Parse the command-line options. |
| 700 | |
| 701 | Automatically changes directory to the requested configdir, and turns on |
| 702 | debugging. Returns the options object. |
| 703 | """ |
| 704 | op = OptionParser(usage = '%prog [-a FILE] [-d DIR]', |
| 705 | version = '%%prog %s' % VERSION) |
| 706 | |
| 707 | op.add_option('-a', '--admin-socket', |
| 708 | metavar = 'FILE', dest = 'tripesock', default = T.tripesock, |
| 709 | help = 'Select socket to connect to [default %default]') |
| 710 | op.add_option('-d', '--directory', |
| 711 | metavar = 'DIR', dest = 'dir', default = T.configdir, |
| 712 | help = 'Select current diretory [default %default]') |
| 713 | op.add_option('-p', '--peerdb', |
| 714 | metavar = 'FILE', dest = 'cdb', default = T.peerdb, |
| 715 | help = 'Select peers database [default %default]') |
| 716 | op.add_option('--daemon', dest = 'daemon', |
| 717 | default = False, action = 'store_true', |
| 718 | help = 'Become a daemon after successful initialization') |
| 719 | op.add_option('--debug', dest = 'debug', |
| 720 | default = False, action = 'store_true', |
| 721 | help = 'Emit debugging trace information') |
| 722 | op.add_option('--startup', dest = 'startup', |
| 723 | default = False, action = 'store_true', |
| 724 | help = 'Being called as part of the server startup') |
| 725 | |
| 726 | opts, args = op.parse_args() |
| 727 | if args: op.error('no arguments permitted') |
| 728 | OS.chdir(opts.dir) |
| 729 | T._debug = opts.debug |
| 730 | return opts |
| 731 | |
| 732 | ## Service table, for running manually. |
| 733 | service_info = [('watch', T.VERSION, { |
| 734 | 'adopted': (0, 0, '', cmd_adopted), |
| 735 | 'kick': (1, 1, 'PEER', cmd_kick) |
| 736 | })] |
| 737 | |
| 738 | if __name__ == '__main__': |
| 739 | opts = parse_options() |
| 740 | T.runservices(opts.tripesock, service_info, |
| 741 | init = init, setup = setup, |
| 742 | daemon = opts.daemon) |
| 743 | |
| 744 | ###----- That's all, folks -------------------------------------------------- |