server

   1 #!/usr/bin/python3
   2
   3 from hippotat import *
   4
   5 import sys
   6 import os
   7
   8 import twisted.internet
   9 from twisted.web.server import NOT_DONE_YET
  10
  11 #import twisted.web.server import Site
  12 #from twisted.web.resource import Resource
  13
  14 import syslog
  15
  16 clients = { }
  17
  18 #---------- "router" ----------
  19
  20 def route(packet, saddr, daddr):
  21   print('TRACE ', saddr, daddr, packet)
  22   try: client = clients[daddr]
  23   except KeyError: dclient = None
  24   if dclient is not None:
  25     dclient.queue_outbound(packet)
  26   elif daddr == c.server or daddr not in c.network:
  27     print('TRACE INBOUND ', saddr, daddr, packet)
  28     queue_inbound(packet)
  29   elif daddr == relay:
  30     log_discard(packet, saddr, daddr, 'relay')
  31   else:
  32     log_discard(packet, saddr, daddr, 'no client')
  33
  34 def log_discard(packet, saddr, daddr, why):
  35   print('DROP ', saddr, daddr, why)
  36 #  syslog.syslog(syslog.LOG_DEBUG,
  37 #                'discarded packet %s -> %s (%s)' % (saddr, daddr, why))
  38
  39 #---------- client ----------
  40
  41 class Client():
  42   def __init__(self, ip, cs, pw):
  43     # instance data members
  44     self._ip = ip
  45     self._cs = cs
  46     self.pw = pw
  47     self._rq = collections.deque() # requests
  48     # self._pq = PacketQueue(...)
  49     # plus from config:
  50     #  .max_batch_down
  51     #  .max_queue_time
  52     #  .max_request_time
  53     #  .target_requests_outstanding
  54
  55     if ip not in c.network:
  56       raise ValueError('client %s not in network' % ip)
  57
  58     for k in ('max_batch_down','max_queue_time','max_request_time',
  59               'target_requests_outstanding'):
  60       req = cfg.getint(cs, k)
  61       limit = cfg.getint('limits',k)
  62       self.__dict__[k] = min(req, limit)
  63
  64     self._pq = PacketQueue(self.max_queue_time)
  65
  66     if ip in clients:
  67       raise ValueError('multiple client cfg sections for %s' % ip)
  68     clients[ip] = self
  69
  70   def process_arriving_data(self, d):
  71     for packet in slip.decode(d):
  72       (saddr, daddr) = packet_addrs(packet)
  73       if saddr != self._ip:
  74         raise ValueError('wrong source address %s' % saddr)
  75       route(packet, saddr, 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(packet)
  85     self._check_outbound()
  86
  87   def http_request(self, request):
  88     request.setHeader('Content-Type','application/octet-stream')
  89     reactor.callLater(self.max_request_time, self._req_cancel, request)
  90     request.notifyFinish().addErrback(self._req_error, request)
  91     self._rq.append(request)
  92     self._check_outbound()
  93
  94   def _check_outbound(self):
  95     while True:
  96       try: request = self._rq[0]
  97       except IndexError: request = None
  98       if request and request.finished:
  99         self._rq.popleft()
 100         continue
 101
 102       if not self._pq.nonempty():
 103         # no packets, oh well
 104         continue
 105
 106       if request is None:
 107         # no request
 108         break
 109
 110       # request, and also some non-expired packets
 111       while True:
 112         packet = self.pq.popleft()
 113         if packet is None: break
 114
 115         encoded = slip.encode(packet)
 116
 117         if request.sentLength > 0:
 118           if (request.sentLength + len(slip.delimiter)
 119               + len(encoded) > self.max_batch_down):
 120             break
 121           request.write(slip.delimiter)
 122
 123         request.write(encoded)
 124         self._pq.popLeft()
 125
 126       assert(request.sentLength)
 127       self._rq.popLeft()
 128       request.finish()
 129       # round again, looking for more to do
 130
 131     while len(self._rq) > self.target_requests_outstanding:
 132       request = self._rq.popleft()
 133       request.finish()
 134
 135 class IphttpResource(twisted.web.resource.Resource):
 136   isLeaf = True
 137   def render_POST(self, request):
 138     # find client, update config, etc.
 139     ci = ipaddr(request.args['i'])
 140     c = clients[ci]
 141     pw = request.args['pw']
 142     if pw != c.pw: raise ValueError('bad password')
 143
 144     # update config
 145
 146     xxx check sanity, do not update
 147     for r, w in (('mbd', 'max_batch_down'),
 148                  ('mqt', 'max_queue_time'),
 149                  ('mrt', 'max_request_time'),
 150                  ('tro', 'target_requests_outstanding')):
 151       try: v = request.args[r]
 152       except KeyError: continue
 153       v = int(v)
 154       c.__dict__[w] = v
 155
 156     try: d = request.args['d']
 157     except KeyError: d = ''
 158
 159     c.process_arriving_data(d)
 160     c.new_request(request)
 161
 162   def render_GET(self, request):
 163     return b'<html><body>hippotat</body></html>'
 164
 165 def start_http():
 166   resource = IphttpResource()
 167   site = twisted.web.server.Site(resource)
 168   for sa in c.saddrs:
 169     ep = sa.make_endpoint()
 170     crash_on_defer(ep.listen(site))
 171
 172 #---------- config and setup ----------
 173
 174 def process_cfg():
 175   process_cfg_common_always()
 176   process_cfg_server()
 177   process_cfg_network()
 178
 179   try:
 180     c.relay = cfg.get('virtual','relay')
 181   except NoOptionError:
 182     for search in c.network.hosts():
 183       if search == c.server: continue
 184       c.relay = search
 185       break
 186
 187   process_cfg_saddrs()
 188   process_cfg_clients(Client)
 189
 190   process_cfg_ipif('server',
 191                    (('local','server'),
 192                     ('peer', 'relay'),
 193                     ('rnets','network')))
 194
 195 common_startup(defcfg)
 196 process_cfg()
 197 start_ipif(c.ipif_command, route)
 198 start_http()
 199 common_run()