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 syslog
  12
  13 clients = { }
  14
  15 def ipaddress(input):
  16   try:
  17     r = ipaddress.IPv4Address(input)
  18   except AddressValueError:
  19     r = ipaddress.IPv6Address(input)
  20   return r
  21
  22 def ipnetwork(input):
  23   try:
  24     r = ipaddress.IPv4Network(input)
  25   except NetworkValueError:
  26     r = ipaddress.IPv6Network(input)
  27   return r
  28
  29 defcfg = u'''
  30 [default]
  31 max_batch_down: 65536
  32 max_queue_time: 10
  33 max_request_time: 54
  34
  35 [global]
  36 max_batch_down: 262144
  37 max_queue_time: 121
  38 max_request_time: 121
  39 '''
  40
  41 def route(packet. daddr):
  42   try: client = clients[daddr]
  43   except KeyError: dclient = None
  44   if dclient is not None:
  45     dclient.queue_outbound_data(packet)
  46   else if daddr = server or daddr not in network:
  47     queue_inbound_data(packet)
  48   else:
  49     syslog.syslog(syslog.LOG_DEBUG, 'no client for %s' % daddr)
  50
  51 class Client():
  52   def __init__(self, ip, cs):
  53     # instance data members
  54     self._ip = ip
  55     self._cs = cs
  56     self.pw = cfg.get(cs, 'password')
  57     # plus from config:
  58     #  .max_batch_down
  59     #  .max_queue_time
  60     #  .max_request_time
  61     for k in ('max_batch_down','max_queue_time','max_request_time'):
  62       req = cfg.getint(cs, k)
  63       limit = cfg.getint('global',k)
  64       self.__dict__[k] = min(req, limit)
  65
  66     def process_arriving_data(self, d):
  67       for packet in slip_decode(d):
  68         (saddr, daddr) = ip_64_addrs(packet)
  69         if saddr != self._ip:
  70           raise ValueError('wrong source address %s' % saddr)
  71         route(packet, daddr)
  72
  73     def _req_cancel(self, request):
  74       request.finish()
  75
  76     def _req_error(self, err, request):
  77       self._req_cancel(request)
  78
  79     def http_request(self, request):
  80       request.setHeader('Content-Type','application/octet-stream')
  81       reactor.callLater(self.max_request_time, self._req_cancel, request)
  82       request.notifyFinish().addErrback(self._req_error, request)
  83
  84 def process_cfg():
  85   global network
  86   global ourself
  87
  88   network = ipnetwork(cfg.get('virtual','network'))
  89   try:
  90     ourself = cfg.get('virtual','server')
  91   except ConfigParser.NoOptionError:
  92     ourself = network.hosts().next()
  93
  94   for cs in cfg.sections():
  95     if not (':' in cs or '.' in cs): continue
  96     ci = ipaddress(cs)
  97     if ci not in network:
  98       raise ValueError('client %s not in network' % ci)
  99     if ci in clients:
 100       raise ValueError('multiple client cfg sections for %s' % ci)
 101     clients[ci] = Client(ci, cs)
 102
 103 class FormPage(Resource):
 104   def render_POST(self, request):
 105     # find client, update config, etc.
 106     ci = ipaddress(request.args['i'])
 107     c = clients[ci]
 108     pw = request.args['pw']
 109     if pw != c.pw: raise ValueError('bad password')
 110
 111     # update config
 112     for r, w in (('mbd', 'max_batch_down'),
 113                  ('mqt', 'max_queue_time'),
 114                  ('mrt', 'max_request_time')):
 115       try: v = request.args[r]
 116       except KeyError: continue
 117       v = int(v)
 118       c.__dict__[w] = v
 119
 120     try: d = request.args['d']
 121     except KeyError: d = ''
 122
 123     c.process_arriving_data(d)
 124     c.new_request(request)