3 # Hippotat - Asinine IP Over HTTP program
4 # hippotatlib/__init__.py - common library code
6 # Copyright 2017 Ian Jackson
10 # This program is free software: you can redistribute it and/or modify
11 # it under the terms of the GNU General Public License as published by
12 # the Free Software Foundation, either version 3 of the License, or
13 # (at your option) any later version.
15 # This program is distributed in the hope that it will be useful,
16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 # GNU General Public License for more details.
20 # You should have received a copy of the GNU General Public License
21 # along with this program, in the file GPLv3. If not,
22 # see <http://www.gnu.org/licenses/>.
26 signal.signal(signal.SIGINT, signal.SIG_DFL)
31 from zope.interface import implementer
34 from twisted.internet import reactor
35 import twisted.internet.endpoints
37 from twisted.logger import LogLevel
38 import twisted.python.constants
39 from twisted.python.constants import NamedConstant
42 from ipaddress import AddressValueError
44 from optparse import OptionParser
46 from configparser import ConfigParser
47 from configparser import NoOptionError
49 from functools import partial
58 import hippotatlib.slip as slip
60 class DBG(twisted.python.constants.Names):
61 INIT = NamedConstant()
62 CONFIG = NamedConstant()
63 ROUTE = NamedConstant()
64 DROP = NamedConstant()
65 OWNSOURCE = NamedConstant()
66 FLOW = NamedConstant()
67 HTTP = NamedConstant()
68 TWISTED = NamedConstant()
69 QUEUE = NamedConstant()
70 HTTP_CTRL = NamedConstant()
71 QUEUE_CTRL = NamedConstant()
72 HTTP_FULL = NamedConstant()
73 CTRL_DUMP = NamedConstant()
74 SLIP_FULL = NamedConstant()
75 DATA_COMPLETE = NamedConstant()
77 _hex_codec = codecs.getencoder('hex_codec')
79 #---------- logging ----------
81 org_stderr = sys.stderr
83 log = twisted.logger.Logger()
86 debug_def_detail = DBG.HTTP
88 def log_debug(dflag, msg, idof=None, d=None):
89 if dflag not in debug_set: return
90 #print('---------------->',repr((dflag, msg, idof, d)), file=sys.stderr)
92 msg = '[%#x] %s' % (id(idof), msg)
95 if not DBG.DATA_COMPLETE in debug_set:
99 d = _hex_codec(d)[0].decode('ascii')
100 msg += ' ' + d + trunc
101 log.info('{dflag} {msgcore}', dflag=dflag, msgcore=msg)
103 def logevent_is_boringtwisted(event):
105 if event.get('log_level') != LogLevel.info:
107 dflag = event.get('dflag')
108 if dflag is False : return False
109 if dflag in debug_set: return False
110 if dflag is None and DBG.TWISTED in debug_set: return False
113 print('EXCEPTION (IN BORINGTWISTED CHECK)',
114 traceback.format_exc(), file=org_stderr)
117 @implementer(twisted.logger.ILogFilterPredicate)
118 class LogNotBoringTwisted:
119 def __call__(self, event):
121 twisted.logger.PredicateResult.no
122 if logevent_is_boringtwisted(event) else
123 twisted.logger.PredicateResult.yes
126 #---------- default config ----------
130 max_batch_down = 65536
132 target_requests_outstanding = 3
134 http_timeout_grace = 5
135 max_requests_outstanding = 6
140 ifname_client = hippo%%d
141 ifname_server = shippo%%d
143 #[server] or [<client>] overrides
144 ipif = userv root ipif %(local)s,%(peer)s,%(mtu)s,slip,%(ifname)s %(rnets)s
146 # relating to virtual network
149 # addrs = 127.0.0.1 ::1
152 # relating to virtual network
153 vvnetwork = 172.24.230.192
154 # vnetwork = <prefix>/<len>
159 # [<client-ip4-or-ipv6-address>]
160 # password = <password> # used by both, must match
163 max_batch_down = 262144
166 target_requests_outstanding = 10
169 # these need to be defined here so that they can be imported by import *
170 cfg = ConfigParser(strict=False)
171 optparser = OptionParser()
173 _mimetrans = bytes.maketrans(b'-'+slip.esc, slip.esc+b'-')
174 def mime_translate(s):
175 # SLIP-encoded packets cannot contain ESC ESC.
176 # Swap `-' and ESC. The result cannot contain `--'
177 return s.translate(_mimetrans)
183 return 'ConfigResults('+repr(self.__dict__)+')'
185 def log_discard(packet, iface, saddr, daddr, why):
187 'discarded packet [%s] %s -> %s: %s' % (iface, saddr, daddr, why),
190 #---------- packet parsing ----------
192 def packet_addrs(packet):
193 version = packet[0] >> 4
197 factory = ipaddress.IPv4Address
201 factory = ipaddress.IPv6Address
203 raise ValueError('unsupported IP version %d' % version)
204 saddr = factory(packet[ saddroff : saddroff + addrlen ])
205 daddr = factory(packet[ saddroff + addrlen : saddroff + addrlen*2 ])
206 return (saddr, daddr)
208 #---------- address handling ----------
212 r = ipaddress.IPv4Address(input)
213 except AddressValueError:
214 r = ipaddress.IPv6Address(input)
217 def ipnetwork(input):
219 r = ipaddress.IPv4Network(input)
220 except NetworkValueError:
221 r = ipaddress.IPv6Network(input)
224 #---------- ipif (SLIP) subprocess ----------
226 class SlipStreamDecoder():
227 def __init__(self, desc, on_packet):
229 self._on_packet = on_packet
231 self._log('__init__')
233 def _log(self, msg, **kwargs):
234 log_debug(DBG.SLIP_FULL, 'slip %s: %s' % (self._desc, msg), **kwargs)
236 def inputdata(self, data):
237 self._log('inputdata', d=data)
238 data = self._buffer + data
240 packets = slip.decode(data, True)
241 self._buffer = packets.pop()
242 for packet in packets:
243 self._maybe_packet(packet)
244 self._log('bufremain', d=self._buffer)
246 def _maybe_packet(self, packet):
247 self._log('maybepacket', d=packet)
249 self._on_packet(packet)
255 packets = slip.decode(data)
256 assert(len(packets) == 1)
257 self._maybe_packet(packets[0])
259 class _IpifProcessProtocol(twisted.internet.protocol.ProcessProtocol):
260 def __init__(self, router):
261 self._router = router
262 self._decoder = SlipStreamDecoder('ipif', self.slip_on_packet)
263 def connectionMade(self): pass
264 def outReceived(self, data):
265 self._decoder.inputdata(data)
266 def slip_on_packet(self, packet):
267 (saddr, daddr) = packet_addrs(packet)
268 if saddr.is_link_local or daddr.is_link_local:
269 log_discard(packet, 'ipif', saddr, daddr, 'link-local')
271 self._router(packet, saddr, daddr)
272 def processEnded(self, status):
273 status.raiseException()
275 def start_ipif(command, router):
276 ipif = _IpifProcessProtocol(router)
277 reactor.spawnProcess(ipif,
278 '/bin/sh',['sh','-xc', command],
279 childFDs={0:'w', 1:'r', 2:2},
283 def queue_inbound(ipif, packet):
284 log_debug(DBG.FLOW, "queue_inbound", d=packet)
285 ipif.transport.write(slip.delimiter)
286 ipif.transport.write(slip.encode(packet))
287 ipif.transport.write(slip.delimiter)
289 #---------- packet queue ----------
292 def __init__(self, desc, max_queue_time):
295 self._max_queue_time = max_queue_time
296 self._pq = collections.deque() # packets
298 def _log(self, dflag, msg, **kwargs):
299 log_debug(dflag, self._desc+' pq: '+msg, **kwargs)
301 def append(self, packet):
302 self._log(DBG.QUEUE, 'append', d=packet)
303 self._pq.append((time.monotonic(), packet))
306 self._log(DBG.QUEUE, 'nonempty ?')
308 try: (queuetime, packet) = self._pq[0]
310 self._log(DBG.QUEUE, 'nonempty ? empty.')
313 age = time.monotonic() - queuetime
314 if age > self._max_queue_time:
315 # strip old packets off the front
316 self._log(DBG.QUEUE, 'dropping (old)', d=packet)
320 self._log(DBG.QUEUE, 'nonempty ? nonempty.')
323 def process(self, sizequery, moredata, max_batch):
324 # sizequery() should return size of batch so far
325 # moredata(s) should add s to batch
326 self._log(DBG.QUEUE, 'process...')
328 try: (dummy, packet) = self._pq[0]
330 self._log(DBG.QUEUE, 'process... empty')
333 self._log(DBG.QUEUE_CTRL, 'process... packet', d=packet)
335 encoded = slip.encode(packet)
338 self._log(DBG.QUEUE_CTRL,
339 'process... (sofar=%d, max=%d) encoded' % (sofar, max_batch),
343 if sofar + len(slip.delimiter) + len(encoded) > max_batch:
344 self._log(DBG.QUEUE_CTRL, 'process... overflow')
346 moredata(slip.delimiter)
351 #---------- error handling ----------
358 print('========== CRASH ==========', err,
359 '===========================', file=sys.stderr)
361 except twisted.internet.error.ReactorNotRunning: pass
363 def crash_on_defer(defer):
364 defer.addErrback(lambda err: crash(err))
366 def crash_on_critical(event):
367 if event.get('log_level') >= LogLevel.critical:
368 crash(twisted.logger.formatEvent(event))
370 #---------- config processing ----------
372 def _cfg_process_putatives():
375 # maps from abstract object to canonical name for cs's
377 def putative(cmap, abstract, canoncs):
379 current_canoncs = cmap[abstract]
383 assert(current_canoncs == canoncs)
384 cmap[abstract] = canoncs
386 server_pat = r'[-.0-9A-Za-z]+'
387 client_pat = r'[.:0-9a-f]+'
388 server_re = regexp.compile(server_pat)
389 serverclient_re = regexp.compile(
390 server_pat + r' ' + '(?:' + client_pat + '|LIMIT)')
392 for cs in cfg.sections():
393 if cs == 'LIMIT' or cs == 'COMMON':
394 # plan A "[LIMIT]" or "[COMMON]"
398 # plan B "[<client>]" part 1
400 except AddressValueError:
402 if server_re.fullmatch(cs):
403 # plan C "[<servername>]"
404 putative(servers, cs, cs)
407 if serverclient_re.fullmatch(cs):
408 # plan D "[<servername> <client>]" part 1
409 (pss,pcs) = cs.split(' ')
412 # plan E "[<servername> LIMIT]"
416 # plan D "[<servername> <client>]" part 2
418 except AddressValueError:
419 # plan F "[<some thing we do not understand>]"
420 # well, we ignore this
421 print('warning: ignoring config section %s' % cs, file=sys.stderr)
424 else: # no AddressValueError
425 # plan D "[<servername> <client]" part 3
426 putative(clients, ci, pcs)
427 putative(servers, pss, pss)
430 else: # no AddressValueError
431 # plan B "[<client>" part 2
432 putative(clients, ci, cs)
435 return (servers, clients)
437 def cfg_process_general(c, ss):
438 c.mtu = cfg1getint(ss, 'mtu')
440 def cfg_process_saddrs(c, ss):
442 def __init__(self, port, addrspec):
446 self.addr = ipaddress.IPv4Address(addrspec)
447 self._endpointfactory = twisted.internet.endpoints.TCP4ServerEndpoint
449 except AddressValueError:
450 self.addr = ipaddress.IPv6Address(addrspec)
451 self._endpointfactory = twisted.internet.endpoints.TCP6ServerEndpoint
452 self._inurl = b'[%s]'
453 def make_endpoint(self):
454 return self._endpointfactory(reactor, self.port,
455 interface= '%s' % self.addr)
457 url = b'http://' + (self._inurl % str(self.addr).encode('ascii'))
458 if self.port != 80: url += b':%d' % self.port
462 return 'ServerAddr'+repr((self.port,self.addr))
464 c.port = cfg1getint(ss,'port')
466 for addrspec in cfg1get(ss, 'addrs').split():
467 sa = ServerAddr(c.port, addrspec)
470 def cfg_process_vnetwork(c, ss):
471 c.vnetwork = ipnetwork(cfg1get(ss,'vnetwork'))
472 if c.vnetwork.num_addresses < 3 + 2:
473 raise ValueError('vnetwork needs at least 2^3 addresses')
475 def cfg_process_vaddr(c, ss):
477 c.vaddr = cfg1get(ss,'vaddr')
478 except NoOptionError:
479 cfg_process_vnetwork(c, ss)
480 c.vaddr = next(c.vnetwork.hosts())
482 def cfg_search_section(key,sections):
483 for section in sections:
484 if cfg.has_option(section, key):
486 raise NoOptionError(key, repr(sections))
488 def cfg_get_raw(*args, **kwargs):
489 # for passing to cfg_search
490 return cfg.get(*args, raw=True, **kwargs)
492 def cfg_search(getter,key,sections):
493 section = cfg_search_section(key,sections)
494 return getter(section, key)
496 def cfg1get(section,key, getter=cfg.get,**kwargs):
497 section = cfg_search_section(key,[section,'COMMON'])
498 return getter(section,key,**kwargs)
500 def cfg1getint(section,key, **kwargs):
501 return cfg1get(section,key, getter=cfg.getint,**kwargs);
503 def cfg_process_client_limited(cc,ss,sections,key):
504 val = cfg_search(cfg1getint, key, sections)
505 lim = cfg_search(cfg1getint, key, ['%s LIMIT' % ss, 'LIMIT'])
506 cc.__dict__[key] = min(val,lim)
508 def cfg_process_client_common(cc,ss,cs,ci):
509 # returns sections to search in, iff password is defined, otherwise None
512 sections = ['%s %s' % (ss,cs),
517 try: pwsection = cfg_search_section('password', sections)
518 except NoOptionError: return None
520 pw = cfg1get(pwsection, 'password')
521 cc.password = pw.encode('utf-8')
523 cfg_process_client_limited(cc,ss,sections,'target_requests_outstanding')
524 cfg_process_client_limited(cc,ss,sections,'http_timeout')
528 def cfg_process_ipif(c, sections, varmap):
530 try: v = getattr(c, s)
531 except AttributeError: continue
534 #print('CFGIPIF',repr((varmap, sections, c.__dict__)),file=sys.stderr)
536 section = cfg_search_section('ipif', sections)
537 c.ipif_command = cfg1get(section,'ipif', vars=c.__dict__)
539 #---------- startup ----------
541 def log_debug_config(m):
542 if not DBG.CONFIG in debug_set: return
543 print('DBG.CONFIG:', m)
545 def common_startup(process_cfg):
546 # calls process_cfg(putative_clients, putative_servers)
548 # ConfigParser hates #-comments after values
549 trailingcomments_re = regexp.compile(r'#.*')
550 cfg.read_string(trailingcomments_re.sub('', defcfg))
553 def readconfig(pathname, mandatory=True):
554 def log(m, p=pathname):
555 if not DBG.CONFIG in debug_set: return
556 log_debug_config('%s: %s' % (m, p))
559 files = os.listdir(pathname)
561 except FileNotFoundError:
566 except NotADirectoryError:
573 re = regexp.compile('[^-A-Za-z0-9_]')
574 for f in os.listdir(pathname):
575 if re.search(f): continue
576 subpath = pathname + '/' + f
579 except FileNotFoundError:
580 log('entry skipped', subpath)
583 log('entry read', subpath)
585 def oc_config(od,os, value, op):
590 def oc_extra_config(od,os, value, op):
593 def read_defconfig():
594 readconfig('/etc/hippotat/config.d', False)
595 readconfig('/etc/hippotat/passwords.d', False)
596 readconfig('/etc/hippotat/master.cfg', False)
598 def oc_defconfig(od,os, value, op):
601 read_defconfig(value)
603 def dfs_less_detailed(dl):
604 return [df for df in DBG.iterconstants() if df <= dl]
606 def ds_default(od,os,dl,op):
609 debug_set |= set(dfs_less_detailed(debug_def_detail))
611 def ds_select(od,os, spec, op):
612 for it in spec.split(','):
614 if it.startswith('-'):
615 mutator = debug_set.discard
618 mutator = debug_set.add
621 dfs = DBG.iterconstants()
625 mapper = dfs_less_detailed
628 mapper = lambda x: [x]
631 dfspec = DBG.lookupByName(it)
633 optparser.error('unknown debug flag %s in --debug-select' % it)
640 optparser.add_option('-D', '--debug',
643 help='enable default debug (to stdout)',
644 callback= ds_default)
646 optparser.add_option('--debug-select',
649 metavar='[-]DFLAG[+]|[-]+,...',
651 '''enable (`-': disable) each specified DFLAG;
652 `+': do same for all "more interesting" DFLAGSs;
653 just `+': all DFLAGs.
654 DFLAGS: ''' + ' '.join([df.name for df in DBG.iterconstants()]),
658 optparser.add_option('-c', '--config',
661 metavar='CONFIGFILE',
666 optparser.add_option('--extra-config',
669 metavar='CONFIGFILE',
672 callback= oc_extra_config)
674 optparser.add_option('--default-config',
676 callback= oc_defconfig)
678 (opts, args) = optparser.parse_args()
679 if len(args): optparser.error('no non-option arguments please')
685 (pss, pcs) = _cfg_process_putatives()
686 process_cfg(opts, pss, pcs)
687 except (configparser.Error, ValueError):
688 traceback.print_exc(file=sys.stderr)
689 print('\nInvalid configuration, giving up.', file=sys.stderr)
693 #print('X', debug_set, file=sys.stderr)
695 log_formatter = twisted.logger.formatEventAsClassicLogText
696 stdout_obs = twisted.logger.FileLogObserver(sys.stdout, log_formatter)
697 stderr_obs = twisted.logger.FileLogObserver(sys.stderr, log_formatter)
698 pred = twisted.logger.LogLevelFilterPredicate(LogLevel.error)
699 stdsomething_obs = twisted.logger.FilteringLogObserver(
700 stderr_obs, [pred], stdout_obs
702 global file_log_observer
703 file_log_observer = twisted.logger.FilteringLogObserver(
704 stdsomething_obs, [LogNotBoringTwisted()]
706 #log_observer = stdsomething_obs
707 twisted.logger.globalLogBeginner.beginLoggingTo(
708 [ file_log_observer, crash_on_critical ]
712 log_debug(DBG.INIT, 'entering reactor')
713 if not _crashing: reactor.run()
714 print('ENDED', file=sys.stderr)