instrumentation/next-share/BaseLib/Core/BitTornado/BT1/NatCheck.py

   1 # Written by Bram Cohen
   2 # see LICENSE.txt for license information
   3
   4 from cStringIO import StringIO
   5 from socket import error as socketerror
   6 try:
   7     True
   8 except:
   9     True = 1
  10     False = 0
  11
  12 protocol_name = 'BitTorrent protocol'
  13
  14 # header, reserved, download id, my id, [length, message]
  15
  16 class NatCheck:
  17     def __init__(self, resultfunc, downloadid, peerid, ip, port, rawserver):
  18         self.resultfunc = resultfunc
  19         self.downloadid = downloadid
  20         self.peerid = peerid
  21         self.ip = ip
  22         self.port = port
  23         self.closed = False
  24         self.buffer = StringIO()
  25         self.next_len = 1
  26         self.next_func = self.read_header_len
  27         try:
  28             self.connection = rawserver.start_connection((ip, port), self)
  29             self.connection.write(chr(len(protocol_name)) + protocol_name +
  30                 (chr(0) * 8) + downloadid)
  31         except socketerror:
  32             self.answer(False)
  33         except IOError:
  34             self.answer(False)
  35
  36     def answer(self, result):
  37         self.closed = True
  38         try:
  39             self.connection.close()
  40         except AttributeError:
  41             pass
  42         self.resultfunc(result, self.downloadid, self.peerid, self.ip, self.port)
  43
  44     def read_header_len(self, s):
  45         if ord(s) != len(protocol_name):
  46             return None
  47         return len(protocol_name), self.read_header
  48
  49     def read_header(self, s):
  50         if s != protocol_name:
  51             return None
  52         return 8, self.read_reserved
  53
  54     def read_reserved(self, s):
  55         return 20, self.read_download_id
  56
  57     def read_download_id(self, s):
  58         if s != self.downloadid:
  59             return None
  60         return 20, self.read_peer_id
  61
  62     def read_peer_id(self, s):
  63         if s != self.peerid:
  64             return None
  65         self.answer(True)
  66         return None
  67
  68     def data_came_in(self, connection, s):
  69         while 1:
  70             if self.closed:
  71                 return
  72             i = self.next_len - self.buffer.tell()
  73             if i > len(s):
  74                 self.buffer.write(s)
  75                 return
  76             self.buffer.write(s[:i])
  77             s = s[i:]
  78             m = self.buffer.getvalue()
  79             self.buffer.reset()
  80             self.buffer.truncate()
  81             x = self.next_func(m)
  82             if x is None:
  83                 if not self.closed:
  84                     self.answer(False)
  85                 return
  86             self.next_len, self.next_func = x
  87
  88     def connection_lost(self, connection):
  89         if not self.closed:
  90             self.closed = True
  91             self.resultfunc(False, self.downloadid, self.peerid, self.ip, self.port)
  92
  93     def connection_flushed(self, connection):
  94         pass