mdw@git.distorted.org.uk Git - hippotat/blob - hippotatd

   1 #!/usr/bin/python3
   2 #
   3 # Hippotat - Asinine IP Over HTTP program
   4 # ./hippotatd - server main program
   5 #
   6 # Copyright 2017 Ian Jackson
   7 #
   8 # This program is free software: you can redistribute it and/or modify
   9 # it under the terms of the GNU Affero General Public License as
  10 # published by the Free Software Foundation, either version 3 of the
  11 # License, or (at your option) any later version, with the "CAF Login
  12 # Exception" as published by Ian Jackson (version 2, or at your option
  13 # any later version) as an Additional Permission.
  14 #
  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 Affero General Public License for more details.
  19 #
  20 # You should have received a copy of the GNU Affero General Public
  21 # License and the CAF Login Exception along with this program, in the
  22 # file AGPLv3+CAFv2.  If not, email Ian Jackson
  23 # <ijackson@chiark.greenend.org.uk>.
  24
  25
  26 from hippotatlib import *
  27
  28 import os
  29 import tempfile
  30 import atexit
  31 import shutil
  32
  33 import twisted.internet
  34 from twisted.web.server import NOT_DONE_YET
  35
  36 import twisted.web.static
  37
  38 import hippotatlib.ownsource
  39 from hippotatlib.ownsource import SourceShipmentPreparer
  40
  41 #import twisted.web.server import Site
  42 #from twisted.web.resource import Resource
  43
  44 import syslog
  45
  46 cleanups = [ ]
  47
  48 clients = { }
  49
  50 #---------- "router" ----------
  51
  52 def route(packet, iface, saddr, daddr):
  53   def lt(dest):
  54     log_debug(DBG.ROUTE, 'route: %s -> %s: %s' % (saddr,daddr,dest), d=packet)
  55   try: dclient = clients[daddr]
  56   except KeyError: dclient = None
  57   if dclient is not None:
  58     lt('client')
  59     dclient.queue_outbound(packet)
  60   elif daddr == c.vaddr or daddr not in c.vnetwork:
  61     lt('inbound')
  62     queue_inbound(ipif, packet)
  63   elif daddr == c.relay:
  64     lt('discard relay')
  65     log_discard(packet, iface, saddr, daddr, 'relay')
  66   else:
  67     lt('discard no-client')
  68     log_discard(packet, iface, saddr, daddr, 'no-client')
  69
  70 #---------- client ----------
  71
  72 class Client():
  73   def __init__(self, ip, cc):
  74     # instance data members
  75     self._ip = ip
  76     self.cc = cc
  77     self._rq = collections.deque() # requests
  78     self._pq = PacketQueue(str(ip), self.cc.max_queue_time)
  79
  80     if ip not in c.vnetwork:
  81       raise ValueError('client %s not in vnetwork' % ip)
  82
  83     if ip in clients:
  84       raise ValueError('multiple client cfg sections for %s' % ip)
  85     clients[ip] = self
  86
  87     self._log(DBG.INIT, 'new')
  88
  89   def _log(self, dflag, msg, **kwargs):
  90     log_debug(dflag, ('client %s: ' % self._ip)+msg, **kwargs)
  91
  92   def process_arriving_data(self, d):
  93     self._log(DBG.FLOW, "req data (enc'd)", d=d)
  94     if not len(d): return
  95     for packet in slip.decode(d):
  96       (saddr, daddr) = packet_addrs(packet)
  97       if saddr != self._ip:
  98         raise ValueError('wrong source address %s' % saddr)
  99       route(packet, self._ip, saddr, daddr)
 100
 101   def _req_cancel(self, request):
 102     self._log(DBG.HTTP_CTRL, 'cancel', idof=request)
 103     request.finish()
 104
 105   def _req_error(self, err, request):
 106     self._log(DBG.HTTP_CTRL, 'error %s' % err, idof=request)
 107     self._req_cancel(request)
 108
 109   def queue_outbound(self, packet):
 110     self._pq.append(packet)
 111     self._check_outbound()
 112
 113   def _req_fin(self, dummy, request, cl):
 114     self._log(DBG.HTTP_CTRL, '_req_fin ' + repr(dummy), idof=request)
 115     try: cl.cancel()
 116     except twisted.internet.error.AlreadyCalled: pass
 117
 118   def new_request(self, request):
 119     request.setHeader('Content-Type','application/octet-stream')
 120     cl = reactor.callLater(self.cc.http_timeout, self._req_cancel, request)
 121     nf = request.notifyFinish()
 122     nf.addErrback(self._req_error, request)
 123     nf.addCallback(self._req_fin, request, cl)
 124     self._rq.append(request)
 125     self._check_outbound()
 126
 127   def _req_write(self, req, d):
 128     self._log(DBG.HTTP, 'req_write ', idof=req, d=d)
 129     req.write(d)
 130
 131   def _check_outbound(self):
 132     log_debug(DBG.HTTP_CTRL, 'CHKO')
 133     while True:
 134       try: request = self._rq[0]
 135       except IndexError: request = None
 136       if request and request.finished:
 137         self._log(DBG.HTTP_CTRL, 'CHKO req finished, discard', idof=request)
 138         self._rq.popleft()
 139         continue
 140
 141       if not self._pq.nonempty():
 142         # no packets, oh well
 143         self._log(DBG.HTTP_CTRL, 'CHKO no packets, OUT-DONE', idof=request)
 144         break
 145
 146       if request is None:
 147         # no request
 148         self._log(DBG.HTTP_CTRL, 'CHKO no request, OUT-DONE', idof=request)
 149         break
 150
 151       self._log(DBG.HTTP_CTRL, 'CHKO processing', idof=request)
 152       # request, and also some non-expired packets
 153       self._pq.process((lambda: request.sentLength),
 154                        (lambda d: self._req_write(request, d)),
 155                        self.cc.max_batch_down)
 156
 157       assert(request.sentLength)
 158       self._rq.popleft()
 159       request.finish()
 160       self._log(DBG.HTTP, 'complete', idof=request)
 161       # round again, looking for more to do
 162
 163     while len(self._rq) > self.cc.target_requests_outstanding:
 164       request = self._rq.popleft()
 165       self._log(DBG.HTTP, 'CHKO above target, returning empty', idof=request)
 166       request.finish()
 167
 168 def process_request(request, desca):
 169   # find client, update config, etc.
 170   metadata = request.args[b'm'][0]
 171   metadata = metadata.split(b'\r\n')
 172   (ci_s, pw, tro, cto) = metadata[0:4]
 173   desca['m[0,2:3]'] = [ci_s, tro, cto]
 174   ci_s = ci_s.decode('utf-8')
 175   tro = int(tro); desca['tro']= tro
 176   cto = int(cto); desca['cto']= cto
 177   ci = ipaddr(ci_s)
 178   desca['ci'] = ci
 179   cl = clients[ci]
 180   if pw != cl.cc.password: raise ValueError('bad password')
 181   desca['pwok']=True
 182
 183   if tro != cl.cc.target_requests_outstanding:
 184     raise ValueError('tro must be %d' % cl.cc.target_requests_outstanding)
 185
 186   if cto < cl.cc.http_timeout:
 187     raise ValueError('cto must be >= %d' % cl.cc.http_timeout)
 188
 189   try:
 190     d = request.args[b'd'][0]
 191     desca['d'] = d
 192     desca['dlen'] = len(d)
 193   except KeyError:
 194     d = b''
 195     desca['dlen'] = None
 196
 197   log_http(desca, 'processing', idof=id(request), d=d)
 198
 199   d = mime_translate(d)
 200
 201   cl.process_arriving_data(d)
 202   cl.new_request(request)
 203
 204 def log_http(desca, msg, **kwargs):
 205   try:
 206     kwargs['d'] = desca['d']
 207     del desca['d']
 208   except KeyError:
 209     pass
 210   log_debug(DBG.HTTP, msg + repr(desca), **kwargs)
 211
 212 class NotStupidResource(twisted.web.resource.Resource):
 213   # why this is not the default is a mystery!
 214   def getChild(self, name, request):
 215     if name == b'': return self
 216     else: return twisted.web.resource.Resource.getChild(name, request)
 217
 218 class IphttpResource(NotStupidResource):
 219   def render_POST(self, request):
 220     log_debug(DBG.HTTP_FULL,
 221               'req recv: ' + repr(request) + ' ' + repr(request.args),
 222               idof=id(request))
 223     desca = {'d': None}
 224     try: process_request(request, desca)
 225     except Exception as e:
 226       emsg = traceback.format_exc()
 227       log_http(desca, 'RETURNING EXCEPTION ' + emsg)
 228       request.setHeader('Content-Type','text/plain; charset="utf-8"')
 229       request.setResponseCode(400)
 230       return (emsg + ' # ' + repr(desca) + '\r\n').encode('utf-8')
 231     log_debug(DBG.HTTP_CTRL, '...', idof=id(request))
 232     return NOT_DONE_YET
 233
 234   def render_GET(self, request):
 235     log_debug(DBG.HTTP, 'GET request')
 236     return b'''
 237 <html><body>
 238 hippotat
 239 <p>
 240 <a href="source">source</a>
 241 (and that of dependency <a href="srcpkgs">packages</a>)
 242 available
 243 </body></html>
 244 '''
 245
 246 def start_http():
 247   resource = IphttpResource()
 248   site = twisted.web.server.Site(resource)
 249
 250   for sa in c.saddrs:
 251     ep = sa.make_endpoint()
 252     crash_on_defer(ep.listen(site))
 253     log_debug(DBG.INIT, 'listening on %s' % sa)
 254
 255   td = tempfile.mkdtemp()
 256
 257   def cleanup():
 258     try: shutil.rmtree(td)
 259     except FileNotFoundError: pass
 260
 261   cleanups.append(cleanup)
 262
 263   ssp = SourceShipmentPreparer(td)
 264   ssp.logger = partial(log_debug, DBG.OWNSOURCE)
 265   ssp.generate()
 266
 267   resource.putChild(b'source',  twisted.web.static.File(ssp.output_paths[0]))
 268   resource.putChild(b'srcpkgs', twisted.web.static.File(ssp.output_paths[1]))
 269
 270   reactor.callLater(0.1, (lambda: log.info('hippotatd started', dflag=False)))
 271
 272 #---------- config and setup ----------
 273
 274 def process_cfg(putative_servers, putative_clients):
 275   global c
 276   c = ConfigResults()
 277   c.server = cfg.get('SERVER','server')
 278
 279   cfg_process_common(c, c.server)
 280   cfg_process_saddrs(c, c.server)
 281   cfg_process_vnetwork(c, c.server)
 282   cfg_process_vaddr(c, c.server)
 283
 284   for (ci,cs) in putative_clients.items():
 285     cc = ConfigResults()
 286     sections = cfg_process_client_common(cc,c.server,cs,ci)
 287     if not sections: continue
 288     cfg_process_client_limited(cc,c.server,sections, 'max_batch_down')
 289     cfg_process_client_limited(cc,c.server,sections, 'max_queue_time')
 290     Client(ci, cc)
 291
 292   try:
 293     c.vrelay = cfg.get(c.server, 'vrelay')
 294   except NoOptionError:
 295     for search in c.vnetwork.hosts():
 296       if search == c.vaddr: continue
 297       c.vrelay = search
 298       break
 299
 300   cfg_process_ipif(c,
 301                    [c.server, 'DEFAULT'],
 302                    (('local','vaddr'),
 303                     ('peer', 'vrelay'),
 304                     ('rnets','vnetwork')))
 305
 306 def catch_termination():
 307   def run_cleanups():
 308     for cleanup in cleanups:
 309       cleanup()
 310
 311   atexit.register(run_cleanups)
 312
 313   def signal_handler(name, sig, *args):
 314     signal.signal(sig, signal.SIG_DFL)
 315     print('exiting due to %s' % name, file=sys.stderr)
 316     run_cleanups()
 317     os.kill(os.getpid(), sig)
 318     raise RuntimeError('did not die due to signal %s !' % name)
 319
 320   for sig in (signal.SIGINT, signal.SIGTERM):
 321     signal.signal(sig, partial(signal_handler, sig.name))
 322
 323 common_startup(process_cfg)
 324 catch_termination()
 325 ipif = start_ipif(c.ipif_command, (lambda p,s,d: route(p,"[ipif]",s,d)))
 326 start_http()
 327 common_run()