server

   1 #!/usr/bin/python2
   2
   3 from twisted.web.server import Site
   4 from twisted.web.resource import Resource
   5 from twisted.web.server import NOT_DONE_YET
   6 from twisted.internet import reactor
   7
   8 import ConfigParser
   9 import ipaddress
  10
  11 import collections
  12
  13 import syslog
  14
  15 clients = { }
  16
  17 def ipaddress(input):
  18   try:
  19     r = ipaddress.IPv4Address(input)
  20   except AddressValueError:
  21     r = ipaddress.IPv6Address(input)
  22   return r
  23
  24 def ipnetwork(input):
  25   try:
  26     r = ipaddress.IPv4Network(input)
  27   except NetworkValueError:
  28     r = ipaddress.IPv6Network(input)
  29   return r
  30
  31 defcfg = u'''
  32 [default]
  33 max_batch_down: 65536
  34 max_queue_time: 10
  35 max_request_time: 54
  36
  37 [global]
  38 max_batch_down: 262144
  39 max_queue_time: 121
  40 max_request_time: 121
  41 '''
  42
  43 def route(packet. daddr):
  44   try: client = clients[daddr]
  45   except KeyError: dclient = None
  46   if dclient is not None:
  47     dclient.queue_outbound(packet)
  48   else if daddr = server or daddr not in network:
  49     queue_inbound(packet)
  50   else:
  51     syslog.syslog(syslog.LOG_DEBUG, 'no client for %s' % daddr)
  52
  53 class Client():
  54   def __init__(self, ip, cs):
  55     # instance data members
  56     self._ip = ip
  57     self._cs = cs
  58     self.pw = cfg.get(cs, 'password')
  59     self._rq = collections.deque() # requests
  60     self._pq = collections.deque() # packets
  61     # plus from config:
  62     #  .max_batch_down
  63     #  .max_queue_time
  64     #  .max_request_time
  65     for k in ('max_batch_down','max_queue_time','max_request_time'):
  66       req = cfg.getint(cs, k)
  67       limit = cfg.getint('global',k)
  68       self.__dict__[k] = min(req, limit)
  69
  70     def process_arriving_data(self, d):
  71       for packet in slip_decode(d):
  72         (saddr, daddr) = ip_64_addrs(packet)
  73         if saddr != self._ip:
  74           raise ValueError('wrong source address %s' % saddr)
  75         route(packet, daddr)
  76
  77     def _req_cancel(self, request):
  78       request.finish()
  79
  80     def _req_error(self, err, request):
  81       self._req_cancel(request)
  82
  83     def queue_outbound(self, packet):
  84       self._pq.append((time.time, packet))
  85
  86     def http_request(self, request):
  87       request.setHeader('Content-Type','application/octet-stream')
  88       reactor.callLater(self.max_request_time, self._req_cancel, request)
  89       request.notifyFinish().addErrback(self._req_error, request)
  90       self._rq.append(request)
  91       self._check_outbound()
  92
  93     def _check_outbound(self):
  94       while True:
  95         try: request = self._rq[0]
  96         except IndexError: request = None
  97         if request and request.finished:
  98           self._rq.popleft()
  99           continue
 100
 101         # now request is an unfinished request, or None
 102         try: (queuetime, packet) = self._pq[0]
 103         except: IndexError:
 104           # no packets, oh well
 105           continue
 106
 107         age = time.time() - queuetime
 108
 109 def process_cfg():
 110   global network
 111   global ourself
 112
 113   network = ipnetwork(cfg.get('virtual','network'))
 114   try:
 115     ourself = cfg.get('virtual','server')
 116   except ConfigParser.NoOptionError:
 117     ourself = network.hosts().next()
 118
 119   for cs in cfg.sections():
 120     if not (':' in cs or '.' in cs): continue
 121     ci = ipaddress(cs)
 122     if ci not in network:
 123       raise ValueError('client %s not in network' % ci)
 124     if ci in clients:
 125       raise ValueError('multiple client cfg sections for %s' % ci)
 126     clients[ci] = Client(ci, cs)
 127
 128 class FormPage(Resource):
 129   def render_POST(self, request):
 130     # find client, update config, etc.
 131     ci = ipaddress(request.args['i'])
 132     c = clients[ci]
 133     pw = request.args['pw']
 134     if pw != c.pw: raise ValueError('bad password')
 135
 136     # update config
 137     for r, w in (('mbd', 'max_batch_down'),
 138                  ('mqt', 'max_queue_time'),
 139                  ('mrt', 'max_request_time')):
 140       try: v = request.args[r]
 141       except KeyError: continue
 142       v = int(v)
 143       c.__dict__[w] = v
 144
 145     try: d = request.args['d']
 146     except KeyError: d = ''
 147
 148     c.process_arriving_data(d)
 149     c.new_request(request)