| 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 | 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 connect 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(*['connect'] + me._map[seq][0] + ['stderr', line]) |
| 127 | |
| 128 | def dbwatch(): |
| 129 | """ |
| 130 | Coroutine function: wake up every minute 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() + 60, lambda: cr.switch()) |
| 139 | main.switch() |
| 140 | if fw.update(): |
| 141 | pinger.rescan(False) |
| 142 | S.notify('connect', '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('connect', what, name, 'stdout', more) |
| 266 | elif kind == 'exit': |
| 267 | if more: S.warn('connect', what, name, *more) |
| 268 | deadp = True |
| 269 | |
| 270 | ###-------------------------------------------------------------------------- |
| 271 | ### Peer database utilities. |
| 272 | |
| 273 | _magic = ['_magic'] # An object distinct from all others |
| 274 | |
| 275 | class Peer (object): |
| 276 | """Representation of a peer in the database.""" |
| 277 | |
| 278 | def __init__(me, peer, cdb = None): |
| 279 | """ |
| 280 | Create a new peer, named PEER. |
| 281 | |
| 282 | Information about the peer is read from the database CDB, or the default |
| 283 | one given on the command-line. |
| 284 | """ |
| 285 | me.name = peer |
| 286 | record = (cdb or CDB.init(opts.cdb))['P' + peer] |
| 287 | me.__dict__.update(M.URLDecode(record, semip = True)) |
| 288 | |
| 289 | def get(me, key, default = _magic, filter = None): |
| 290 | """ |
| 291 | Get the information stashed under KEY from the peer's database record. |
| 292 | |
| 293 | If DEFAULT is given, then use it if the database doesn't contain the |
| 294 | necessary information. If no DEFAULT is given, then report an error. If |
| 295 | a FILTER function is given then apply it to the information from the |
| 296 | database before returning it. |
| 297 | """ |
| 298 | attr = me.__dict__.get(key, default) |
| 299 | if attr is _magic: |
| 300 | raise T.TripeJobError('malformed-peer', me.name, 'missing-key', key) |
| 301 | elif filter is not None: |
| 302 | attr = filter(attr) |
| 303 | return attr |
| 304 | |
| 305 | def has(me, key): |
| 306 | """ |
| 307 | Return whether the peer's database record has the KEY. |
| 308 | """ |
| 309 | return key in me.__dict__ |
| 310 | |
| 311 | def list(me): |
| 312 | """ |
| 313 | Iterate over the available keys in the peer's database record. |
| 314 | """ |
| 315 | return me.__dict__.iterkeys() |
| 316 | |
| 317 | def boolean(value): |
| 318 | """Parse VALUE as a boolean.""" |
| 319 | return value in ['t', 'true', 'y', 'yes', 'on'] |
| 320 | |
| 321 | ###-------------------------------------------------------------------------- |
| 322 | ### Waking up and watching peers. |
| 323 | |
| 324 | def run_connect(peer, cmd): |
| 325 | """ |
| 326 | Start the job of connecting to the passive PEER. |
| 327 | |
| 328 | The CMD string is a shell command which will connect to the peer (via some |
| 329 | back-channel, say ssh and userv), issue a command |
| 330 | |
| 331 | SVCSUBMIT connect passive [OPTIONS] USER |
| 332 | |
| 333 | and write the resulting challenge to standard error. |
| 334 | """ |
| 335 | q = T.Queue() |
| 336 | cmd = Command(['connect', peer.name], q, 'connect', |
| 337 | ['/bin/sh', '-c', cmd], None) |
| 338 | _, kind, more = q.peek() |
| 339 | if kind == 'stdout': |
| 340 | if more is None: |
| 341 | S.warn('connect', 'connect', peer.name, 'unexpected-eof') |
| 342 | else: |
| 343 | chal = more |
| 344 | S.greet(peer.name, chal) |
| 345 | q.get() |
| 346 | potwatch('connect', peer.name, q) |
| 347 | |
| 348 | def run_disconnect(peer, cmd): |
| 349 | """ |
| 350 | Start the job of disconnecting from a passive PEER. |
| 351 | |
| 352 | The CMD string is a shell command which will disconnect from the peer. |
| 353 | """ |
| 354 | q = T.Queue() |
| 355 | cmd = Command(['disconnect', peer.name], q, 'disconnect', |
| 356 | ['/bin/sh', '-c', cmd], None) |
| 357 | potwatch('disconnect', peer.name, q) |
| 358 | |
| 359 | _pingseq = 0 |
| 360 | class PingPeer (object): |
| 361 | """ |
| 362 | Object representing a peer which we are pinging to ensure that it is still |
| 363 | present. |
| 364 | |
| 365 | PingPeer objects are held by the Pinger (q.v.). The Pinger maintains an |
| 366 | event queue -- which saves us from having an enormous swarm of coroutines |
| 367 | -- but most of the actual work is done here. |
| 368 | |
| 369 | In order to avoid confusion between different PingPeer instances for the |
| 370 | same actual peer, each PingPeer has a sequence number (its `seq' |
| 371 | attribute). Events for the PingPeer are identified by a (PEER, SEQ) pair. |
| 372 | (Using the PingPeer instance itself will prevent garbage collection of |
| 373 | otherwise defunct instances.) |
| 374 | """ |
| 375 | |
| 376 | def __init__(me, pinger, queue, peer, pingnow): |
| 377 | """ |
| 378 | Create a new PingPeer. |
| 379 | |
| 380 | The PINGER is the Pinger object we should send the results to. This is |
| 381 | used when we remove ourselves, if the peer has been explicitly removed. |
| 382 | |
| 383 | The QUEUE is the event queue on which timer and ping-command events |
| 384 | should be written. |
| 385 | |
| 386 | The PEER is a `Peer' object describing the peer. |
| 387 | |
| 388 | If PINGNOW is true, then immediately start pinging the peer. Otherwise |
| 389 | wait until the usual retry interval. |
| 390 | """ |
| 391 | global _pingseq |
| 392 | me._pinger = pinger |
| 393 | me._q = queue |
| 394 | me._peer = peer.name |
| 395 | me.update(peer) |
| 396 | me.seq = _pingseq |
| 397 | _pingseq += 1 |
| 398 | me._failures = 0 |
| 399 | me._sabotage = False |
| 400 | me._last = '-' |
| 401 | me._nping = 0 |
| 402 | me._nlost = 0 |
| 403 | me._sigma_t = 0 |
| 404 | me._sigma_t2 = 0 |
| 405 | me._min = me._max = '-' |
| 406 | if pingnow: |
| 407 | me._timer = None |
| 408 | me._ping() |
| 409 | else: |
| 410 | me._timer = M.SelTimer(time() + me._every, me._time) |
| 411 | |
| 412 | def update(me, peer): |
| 413 | """ |
| 414 | Refreshes the timer parameters for this peer. We don't, however, |
| 415 | immediately reschedule anything: that will happen next time anything |
| 416 | interesting happens. |
| 417 | """ |
| 418 | if peer is None: peer = Peer(me._peer) |
| 419 | assert peer.name == me._peer |
| 420 | me._every = peer.get('every', filter = T.timespec, default = 120) |
| 421 | me._timeout = peer.get('timeout', filter = T.timespec, default = 10) |
| 422 | me._retries = peer.get('retries', filter = int, default = 5) |
| 423 | me._connectp = peer.has('connect') |
| 424 | return me |
| 425 | |
| 426 | def _ping(me): |
| 427 | """ |
| 428 | Send a ping to the peer; the result is sent to the Pinger's event queue. |
| 429 | """ |
| 430 | S.rawcommand(T.TripeAsynchronousCommand( |
| 431 | me._q, (me._peer, me.seq), |
| 432 | ['EPING', |
| 433 | '-background', S.bgtag(), |
| 434 | '-timeout', str(me._timeout), |
| 435 | '--', |
| 436 | me._peer])) |
| 437 | |
| 438 | def _reconnect(me): |
| 439 | peer = Peer(me._peer) |
| 440 | if me._connectp: |
| 441 | S.warn('connect', 'reconnecting', me._peer) |
| 442 | S.forcekx(me._peer) |
| 443 | T.spawn(run_connect, peer, peer.get('connect')) |
| 444 | me._timer = M.SelTimer(time() + me._every, me._time) |
| 445 | me._sabotage = False |
| 446 | else: |
| 447 | S.kill(me._peer) |
| 448 | |
| 449 | def event(me, code, stuff): |
| 450 | """ |
| 451 | Respond to an event which happened to this peer. |
| 452 | |
| 453 | Timer events indicate that we should start a new ping. (The server has |
| 454 | its own timeout which detects lost packets.) |
| 455 | |
| 456 | We trap unknown-peer responses and detach from the Pinger. |
| 457 | |
| 458 | If the ping fails and we run out of retries, we attempt to restart the |
| 459 | connection. |
| 460 | """ |
| 461 | if code == 'TIMER': |
| 462 | me._failures = 0 |
| 463 | me._ping() |
| 464 | elif code == 'FAIL': |
| 465 | S.notify('connect', 'ping-failed', me._peer, *stuff) |
| 466 | if not stuff: |
| 467 | pass |
| 468 | elif stuff[0] == 'unknown-peer': |
| 469 | me._pinger.kill(me._peer) |
| 470 | elif stuff[0] == 'ping-send-failed': |
| 471 | me._reconnect() |
| 472 | elif code == 'INFO': |
| 473 | outcome = stuff[0] |
| 474 | if outcome == 'ping-ok' and me._sabotage: |
| 475 | outcome = 'ping-timeout' |
| 476 | if outcome == 'ping-ok': |
| 477 | if me._failures > 0: |
| 478 | S.warn('connect', 'ping-ok', me._peer) |
| 479 | t = float(stuff[1]) |
| 480 | me._last = '%.1fms' % t |
| 481 | me._sigma_t += t |
| 482 | me._sigma_t2 += t*t |
| 483 | me._nping += 1 |
| 484 | if me._min == '-' or t < me._min: me._min = t |
| 485 | if me._max == '-' or t > me._max: me._max = t |
| 486 | me._timer = M.SelTimer(time() + me._every, me._time) |
| 487 | elif outcome == 'ping-timeout': |
| 488 | me._failures += 1 |
| 489 | me._nlost += 1 |
| 490 | S.warn('connect', 'ping-timeout', me._peer, |
| 491 | 'attempt', str(me._failures), 'of', str(me._retries)) |
| 492 | if me._failures < me._retries: |
| 493 | me._ping() |
| 494 | me._last = 'timeout' |
| 495 | else: |
| 496 | me._reconnect() |
| 497 | me._last = 'reconnect' |
| 498 | elif outcome == 'ping-peer-died': |
| 499 | me._pinger.kill(me._peer) |
| 500 | |
| 501 | def sabotage(me): |
| 502 | """Sabotage the peer, for testing purposes.""" |
| 503 | me._sabotage = True |
| 504 | if me._timer: me._timer.kill() |
| 505 | T.defer(me._time) |
| 506 | |
| 507 | def info(me): |
| 508 | if not me._nping: |
| 509 | mean = sd = '-' |
| 510 | else: |
| 511 | mean = me._sigma_t/me._nping |
| 512 | sd = sqrt(me._sigma_t2/me._nping - mean*mean) |
| 513 | n = me._nping + me._nlost |
| 514 | if not n: pclost = '-' |
| 515 | else: pclost = '%d' % ((100*me._nlost + n//2)//n) |
| 516 | return { 'last-ping': me._last, |
| 517 | 'mean-ping': '%.1fms' % mean, |
| 518 | 'sd-ping': '%.1fms' % sd, |
| 519 | 'n-ping': '%d' % me._nping, |
| 520 | 'n-lost': '%d' % me._nlost, |
| 521 | 'percent-lost': pclost, |
| 522 | 'min-ping': '%.1fms' % me._min, |
| 523 | 'max-ping': '%.1fms' % me._max, |
| 524 | 'state': me._timer and 'idle' or 'check', |
| 525 | 'failures': me._failures } |
| 526 | |
| 527 | @T._callback |
| 528 | def _time(me): |
| 529 | """ |
| 530 | Handle timer callbacks by posting a timeout event on the queue. |
| 531 | """ |
| 532 | me._timer = None |
| 533 | me._q.put(((me._peer, me.seq), 'TIMER', None)) |
| 534 | |
| 535 | def __str__(me): |
| 536 | return 'PingPeer(%s, %d, f = %d)' % (me._peer, me.seq, me._failures) |
| 537 | def __repr__(me): |
| 538 | return str(me) |
| 539 | |
| 540 | class Pinger (T.Coroutine): |
| 541 | """ |
| 542 | The Pinger keeps track of the peers which we expect to be connected and |
| 543 | takes action if they seem to stop responding. |
| 544 | |
| 545 | There is usually only one Pinger, called pinger. |
| 546 | |
| 547 | The Pinger maintains a collection of PingPeer objects, and an event queue. |
| 548 | The PingPeers direct the results of their pings, and timer events, to the |
| 549 | event queue. The Pinger's coroutine picks items off the queue and |
| 550 | dispatches them back to the PingPeers as appropriate. |
| 551 | """ |
| 552 | |
| 553 | def __init__(me): |
| 554 | """Initialize the Pinger.""" |
| 555 | T.Coroutine.__init__(me) |
| 556 | me._peers = {} |
| 557 | me._q = T.Queue() |
| 558 | |
| 559 | def run(me): |
| 560 | """ |
| 561 | Coroutine function: reads the pinger queue and sends events to the |
| 562 | PingPeer objects they correspond to. |
| 563 | """ |
| 564 | while True: |
| 565 | (peer, seq), code, stuff = me._q.get() |
| 566 | if peer in me._peers and seq == me._peers[peer].seq: |
| 567 | me._peers[peer].event(code, stuff) |
| 568 | |
| 569 | def add(me, peer, pingnow): |
| 570 | """ |
| 571 | Add PEER to the collection of peers under the Pinger's watchful eye. |
| 572 | The arguments are as for PingPeer: see above. |
| 573 | """ |
| 574 | me._peers[peer.name] = PingPeer(me, me._q, peer, pingnow) |
| 575 | return me |
| 576 | |
| 577 | def kill(me, peername): |
| 578 | """Remove PEER from the peers being watched by the Pinger.""" |
| 579 | try: del me._peers[peername] |
| 580 | except KeyError: pass |
| 581 | return me |
| 582 | |
| 583 | def rescan(me, startup): |
| 584 | """ |
| 585 | General resynchronization method. |
| 586 | |
| 587 | We scan the list of peers (with connect scripts) known at the server. |
| 588 | Any which are known to the Pinger but aren't known to the server are |
| 589 | removed from our list; newly arrived peers are added. (Note that a peer |
| 590 | can change state here either due to the server sneakily changing its list |
| 591 | without issuing notifications or, more likely, the database changing its |
| 592 | idea of whether a peer is interesting.) Finally, PingPeers which are |
| 593 | still present are prodded to update their timing parameters. |
| 594 | |
| 595 | This method is called once at startup to pick up the peers already |
| 596 | installed, and again by the dbwatcher coroutine when it detects a change |
| 597 | to the database. |
| 598 | """ |
| 599 | if T._debug: print '# rescan peers' |
| 600 | correct = {} |
| 601 | start = {} |
| 602 | for name in S.list(): |
| 603 | try: peer = Peer(name) |
| 604 | except KeyError: continue |
| 605 | if peer.get('watch', filter = boolean, default = False): |
| 606 | if T._debug: print '# interesting peer %s' % peer |
| 607 | correct[peer.name] = start[peer.name] = peer |
| 608 | elif startup: |
| 609 | if T._debug: print '# peer %s ready for adoption' % peer |
| 610 | start[peer.name] = peer |
| 611 | for name, obj in me._peers.items(): |
| 612 | try: |
| 613 | peer = correct[name] |
| 614 | except KeyError: |
| 615 | if T._debug: print '# peer %s vanished' % name |
| 616 | del me._peers[name] |
| 617 | else: |
| 618 | obj.update(peer) |
| 619 | for name, peer in start.iteritems(): |
| 620 | if name in me._peers: continue |
| 621 | if startup: |
| 622 | if T._debug: print '# setting up peer %s' % name |
| 623 | ifname = S.ifname(name) |
| 624 | addr = S.addr(name) |
| 625 | T.defer(adoptpeer, peer, ifname, *addr) |
| 626 | else: |
| 627 | if T._debug: print '# adopting new peer %s' % name |
| 628 | me.add(peer, True) |
| 629 | return me |
| 630 | |
| 631 | def adopted(me): |
| 632 | """ |
| 633 | Returns the list of peers being watched by the Pinger. |
| 634 | """ |
| 635 | return me._peers.keys() |
| 636 | |
| 637 | def find(me, name): |
| 638 | """Return the PingPeer with the given name.""" |
| 639 | return me._peers[name] |
| 640 | |
| 641 | ###-------------------------------------------------------------------------- |
| 642 | ### New connections. |
| 643 | |
| 644 | def encode_envvars(env, prefix, vars): |
| 645 | """ |
| 646 | Encode the variables in VARS suitably for including in a program |
| 647 | environment. Lowercase letters in variable names are forced to uppercase; |
| 648 | runs of non-alphanumeric characters are replaced by single underscores; and |
| 649 | the PREFIX is prepended. The resulting variables are written to ENV. |
| 650 | """ |
| 651 | for k, v in vars.iteritems(): |
| 652 | env[prefix + r_bad.sub('_', k.upper())] = v |
| 653 | |
| 654 | r_bad = RX.compile(r'[\W_]+') |
| 655 | def envvars(peer): |
| 656 | """ |
| 657 | Translate the database information for a PEER into a dictionary of |
| 658 | environment variables with plausible upper-case names and a P_ prefix. |
| 659 | Also collect the crypto information into A_ variables. |
| 660 | """ |
| 661 | env = {} |
| 662 | encode_envvars(env, 'P_', dict([(k, peer.get(k)) for k in peer.list()])) |
| 663 | encode_envvars(env, 'A_', S.algs(peer.name)) |
| 664 | return env |
| 665 | |
| 666 | def run_ifupdown(what, peer, *args): |
| 667 | """ |
| 668 | Run the interface up/down script for a peer. |
| 669 | |
| 670 | WHAT is 'ifup' or 'ifdown'. PEER names the peer in question. ARGS is a |
| 671 | list of arguments to pass to the script, in addition to the peer name. |
| 672 | |
| 673 | The command is run and watched in the background by potwatch. |
| 674 | """ |
| 675 | q = T.Queue() |
| 676 | c = Command([what, peer.name], q, what, |
| 677 | M.split(peer.get(what), quotep = True)[0] + |
| 678 | [peer.name] + list(args), |
| 679 | envvars(peer)) |
| 680 | potwatch(what, peer.name, q) |
| 681 | |
| 682 | def adoptpeer(peer, ifname, *addr): |
| 683 | """ |
| 684 | Add a new peer to our collection. |
| 685 | |
| 686 | PEER is the `Peer' object; IFNAME is the interface name for its tunnel; and |
| 687 | ADDR is the list of tokens representing its address. |
| 688 | |
| 689 | We try to bring up the interface and provoke a connection to the peer if |
| 690 | it's passive. |
| 691 | """ |
| 692 | if peer.has('ifup'): |
| 693 | T.Coroutine(run_ifupdown, name = 'ifup %s' % peer.name) \ |
| 694 | .switch('ifup', peer, ifname, *addr) |
| 695 | cmd = peer.get('connect', default = None) |
| 696 | if cmd is not None: |
| 697 | T.Coroutine(run_connect, name = 'connect %s' % peer.name) \ |
| 698 | .switch(peer, cmd) |
| 699 | if peer.get('watch', filter = boolean, default = False): |
| 700 | pinger.add(peer, False) |
| 701 | |
| 702 | def disownpeer(peer): |
| 703 | """Drop the PEER from the Pinger and put its interface to bed.""" |
| 704 | try: pinger.kill(peer) |
| 705 | except KeyError: pass |
| 706 | cmd = peer.get('disconnect', default = None) |
| 707 | if cmd is not None: |
| 708 | T.Coroutine(run_disconnect, name = 'disconnect %s' % peer.name) \ |
| 709 | .switch(peer, cmd) |
| 710 | if peer.has('ifdown'): |
| 711 | T.Coroutine(run_ifupdown, name = 'ifdown %s' % peer.name) \ |
| 712 | .switch('ifdown', peer) |
| 713 | |
| 714 | def addpeer(peer, addr): |
| 715 | """ |
| 716 | Process a connect request from a new peer PEER on address ADDR. |
| 717 | |
| 718 | Any existing peer with this name is disconnected from the server. |
| 719 | """ |
| 720 | if peer.name in S.list(): |
| 721 | S.kill(peer.name) |
| 722 | try: |
| 723 | booltrue = ['t', 'true', 'y', 'yes', 'on'] |
| 724 | S.add(peer.name, |
| 725 | tunnel = peer.get('tunnel', None), |
| 726 | keepalive = peer.get('keepalive', None), |
| 727 | key = peer.get('key', None), |
| 728 | priv = peer.get('priv', None), |
| 729 | mobile = peer.get('mobile', 'nil') in booltrue, |
| 730 | cork = peer.get('cork', 'nil') in booltrue, |
| 731 | *addr) |
| 732 | except T.TripeError, exc: |
| 733 | raise T.TripeJobError(*exc.args) |
| 734 | |
| 735 | ## Dictionary mapping challenges to waiting passive-connection coroutines. |
| 736 | chalmap = {} |
| 737 | |
| 738 | def notify(_, code, *rest): |
| 739 | """ |
| 740 | Watch for notifications. |
| 741 | |
| 742 | We trap ADD and KILL notifications, and send them straight to adoptpeer and |
| 743 | disownpeer respectively; and dispatch GREET notifications to the |
| 744 | corresponding waiting coroutine. |
| 745 | """ |
| 746 | if code == 'ADD': |
| 747 | try: p = Peer(rest[0]) |
| 748 | except KeyError: return |
| 749 | adoptpeer(p, *rest[1:]) |
| 750 | elif code == 'KILL': |
| 751 | try: p = Peer(rest[0]) |
| 752 | except KeyError: return |
| 753 | disownpeer(p, *rest[1:]) |
| 754 | elif code == 'GREET': |
| 755 | chal = rest[0] |
| 756 | try: cr = chalmap[chal] |
| 757 | except KeyError: pass |
| 758 | else: cr.switch(rest[1:]) |
| 759 | |
| 760 | ###-------------------------------------------------------------------------- |
| 761 | ### Command implementation. |
| 762 | |
| 763 | def cmd_kick(name): |
| 764 | """ |
| 765 | kick NAME: Force a new connection attempt for the NAMEd peer. |
| 766 | """ |
| 767 | try: pp = pinger.find(name) |
| 768 | except KeyError: raise T.TripeJobError('peer-not-adopted', name) |
| 769 | try: peer = Peer(name) |
| 770 | except KeyError: raise T.TripeJobError('unknown-peer', name) |
| 771 | conn = peer.get('connect', None) |
| 772 | if conn: T.spawn(run_connect, peer, peer.get('connect')) |
| 773 | else: T.spawn(lambda p: S.forcekx(p.name), peer) |
| 774 | |
| 775 | def cmd_adopted(): |
| 776 | """ |
| 777 | adopted: Report a list of adopted peers. |
| 778 | """ |
| 779 | for name in pinger.adopted(): |
| 780 | T.svcinfo(name) |
| 781 | |
| 782 | def cmd_active(name): |
| 783 | """ |
| 784 | active NAME: Handle an active connection request for the peer called NAME. |
| 785 | |
| 786 | The appropriate address is read from the database automatically. |
| 787 | """ |
| 788 | try: peer = Peer(name) |
| 789 | except KeyError: raise T.TripeJobError('unknown-peer', name) |
| 790 | addr = peer.get('peer') |
| 791 | if addr == 'PASSIVE': |
| 792 | raise T.TripeJobError('passive-peer', name) |
| 793 | addpeer(peer, M.split(addr, quotep = True)[0]) |
| 794 | |
| 795 | def cmd_listactive(): |
| 796 | """ |
| 797 | list: Report a list of the available active peers. |
| 798 | """ |
| 799 | cdb = CDB.init(opts.cdb) |
| 800 | for key in cdb.keys(): |
| 801 | if key.startswith('P') and Peer(key[1:]).get('peer', '') != 'PASSIVE': |
| 802 | T.svcinfo(key[1:]) |
| 803 | |
| 804 | def cmd_info(name): |
| 805 | """ |
| 806 | info NAME: Report the database entries for the named peer. |
| 807 | """ |
| 808 | try: peer = Peer(name) |
| 809 | except KeyError: raise T.TripeJobError('unknown-peer', name) |
| 810 | d = {} |
| 811 | try: pp = pinger.find(name) |
| 812 | except KeyError: pass |
| 813 | else: d.update(pp.info()) |
| 814 | items = list(peer.list()) + d.keys() |
| 815 | items.sort() |
| 816 | for i in items: |
| 817 | try: v = d[i] |
| 818 | except KeyError: v = peer.get(i) |
| 819 | T.svcinfo('%s=%s' % (i, v)) |
| 820 | |
| 821 | def cmd_userpeer(user): |
| 822 | """ |
| 823 | userpeer USER: Report the peer name for the named user. |
| 824 | """ |
| 825 | try: name = CDB.init(opts.cdb)['U' + user] |
| 826 | except KeyError: raise T.TripeJobError('unknown-user', user) |
| 827 | T.svcinfo(name) |
| 828 | |
| 829 | def cmd_passive(*args): |
| 830 | """ |
| 831 | passive [OPTIONS] USER: Await the arrival of the named USER. |
| 832 | |
| 833 | Report a challenge; when (and if!) the server receives a greeting quoting |
| 834 | this challenge, add the corresponding peer to the server. |
| 835 | """ |
| 836 | timeout = 30 |
| 837 | op = T.OptParse(args, ['-timeout']) |
| 838 | for opt in op: |
| 839 | if opt == '-timeout': |
| 840 | timeout = T.timespec(op.arg()) |
| 841 | user, = op.rest(1, 1) |
| 842 | try: name = CDB.init(opts.cdb)['U' + user] |
| 843 | except KeyError: raise T.TripeJobError('unknown-user', user) |
| 844 | try: peer = Peer(name) |
| 845 | except KeyError: raise T.TripeJobError('unknown-peer', name) |
| 846 | chal = S.getchal() |
| 847 | cr = T.Coroutine.getcurrent() |
| 848 | timer = M.SelTimer(time() + timeout, lambda: cr.switch(None)) |
| 849 | try: |
| 850 | T.svcinfo(chal) |
| 851 | chalmap[chal] = cr |
| 852 | addr = cr.parent.switch() |
| 853 | if addr is None: |
| 854 | raise T.TripeJobError('connect-timeout') |
| 855 | addpeer(peer, addr) |
| 856 | finally: |
| 857 | del chalmap[chal] |
| 858 | |
| 859 | def cmd_sabotage(name): |
| 860 | """ |
| 861 | sabotage NAME: Sabotage the NAMEd peer so that we think it can't be pinged. |
| 862 | """ |
| 863 | try: pp = pinger.find(name) |
| 864 | except KeyError: raise T.TripeJobError('unknown-peer', name) |
| 865 | pp.sabotage() |
| 866 | |
| 867 | ###-------------------------------------------------------------------------- |
| 868 | ### Start up. |
| 869 | |
| 870 | def setup(): |
| 871 | """ |
| 872 | Service setup. |
| 873 | |
| 874 | Register the notification watcher, rescan the peers, and add automatic |
| 875 | active peers. |
| 876 | """ |
| 877 | S.handler['NOTE'] = notify |
| 878 | S.watch('+n') |
| 879 | |
| 880 | pinger.rescan(opts.startup) |
| 881 | |
| 882 | if opts.startup: |
| 883 | cdb = CDB.init(opts.cdb) |
| 884 | try: |
| 885 | autos = cdb['%AUTO'] |
| 886 | except KeyError: |
| 887 | autos = '' |
| 888 | for name in M.split(autos)[0]: |
| 889 | try: |
| 890 | peer = Peer(name, cdb) |
| 891 | addpeer(peer, M.split(peer.get('peer'), quotep = True)[0]) |
| 892 | except T.TripeJobError, err: |
| 893 | S.warn('connect', 'auto-add-failed', name, *err.args) |
| 894 | |
| 895 | def init(): |
| 896 | """ |
| 897 | Initialization to be done before service startup. |
| 898 | """ |
| 899 | global errorwatch, childwatch, pinger |
| 900 | errorwatch = ErrorWatch() |
| 901 | childwatch = ChildWatch() |
| 902 | pinger = Pinger() |
| 903 | T.Coroutine(dbwatch, name = 'dbwatch').switch() |
| 904 | errorwatch.switch() |
| 905 | pinger.switch() |
| 906 | |
| 907 | def parse_options(): |
| 908 | """ |
| 909 | Parse the command-line options. |
| 910 | |
| 911 | Automatically changes directory to the requested configdir, and turns on |
| 912 | debugging. Returns the options object. |
| 913 | """ |
| 914 | op = OptionParser(usage = '%prog [-a FILE] [-d DIR]', |
| 915 | version = '%%prog %s' % VERSION) |
| 916 | |
| 917 | op.add_option('-a', '--admin-socket', |
| 918 | metavar = 'FILE', dest = 'tripesock', default = T.tripesock, |
| 919 | help = 'Select socket to connect to [default %default]') |
| 920 | op.add_option('-d', '--directory', |
| 921 | metavar = 'DIR', dest = 'dir', default = T.configdir, |
| 922 | help = 'Select current diretory [default %default]') |
| 923 | op.add_option('-p', '--peerdb', |
| 924 | metavar = 'FILE', dest = 'cdb', default = T.peerdb, |
| 925 | help = 'Select peers database [default %default]') |
| 926 | op.add_option('--daemon', dest = 'daemon', |
| 927 | default = False, action = 'store_true', |
| 928 | help = 'Become a daemon after successful initialization') |
| 929 | op.add_option('--debug', dest = 'debug', |
| 930 | default = False, action = 'store_true', |
| 931 | help = 'Emit debugging trace information') |
| 932 | op.add_option('--startup', dest = 'startup', |
| 933 | default = False, action = 'store_true', |
| 934 | help = 'Being called as part of the server startup') |
| 935 | |
| 936 | opts, args = op.parse_args() |
| 937 | if args: op.error('no arguments permitted') |
| 938 | OS.chdir(opts.dir) |
| 939 | T._debug = opts.debug |
| 940 | return opts |
| 941 | |
| 942 | ## Service table, for running manually. |
| 943 | service_info = [('connect', T.VERSION, { |
| 944 | 'adopted': (0, 0, '', cmd_adopted), |
| 945 | 'kick': (1, 1, 'PEER', cmd_kick), |
| 946 | 'passive': (1, None, '[OPTIONS] USER', cmd_passive), |
| 947 | 'active': (1, 1, 'PEER', cmd_active), |
| 948 | 'info': (1, 1, 'PEER', cmd_info), |
| 949 | 'list-active': (0, 0, '', cmd_listactive), |
| 950 | 'userpeer': (1, 1, 'USER', cmd_userpeer), |
| 951 | 'sabotage': (1, 1, 'PEER', cmd_sabotage) |
| 952 | })] |
| 953 | |
| 954 | if __name__ == '__main__': |
| 955 | opts = parse_options() |
| 956 | T.runservices(opts.tripesock, service_info, |
| 957 | init = init, setup = setup, |
| 958 | daemon = opts.daemon) |
| 959 | |
| 960 | ###----- That's all, folks -------------------------------------------------- |