p2pool/util/p2protocol.py

   1 '''
   2 Generic message-based protocol used by Bitcoin and P2Pool for P2P communication
   3 '''
   4
   5 import hashlib
   6 import struct
   7
   8 from twisted.internet import protocol
   9 from twisted.python import log
  10
  11 import p2pool
  12 from p2pool.util import datachunker, variable
  13
  14 class TooLong(Exception):
  15     pass
  16
  17 class Protocol(protocol.Protocol):
  18     def __init__(self, message_prefix, max_payload_length, traffic_happened=variable.Event()):
  19         self._message_prefix = message_prefix
  20         self._max_payload_length = max_payload_length
  21         self.dataReceived2 = datachunker.DataChunker(self.dataReceiver())
  22         self.paused_var = variable.Variable(False)
  23         self.traffic_happened = traffic_happened
  24
  25     def connectionMade(self):
  26         self.transport.registerProducer(self, True)
  27
  28     def pauseProducing(self):
  29         self.paused_var.set(True)
  30
  31     def resumeProducing(self):
  32         self.paused_var.set(False)
  33
  34     def stopProducing(self):
  35         pass
  36
  37     def dataReceived(self, data):
  38         self.traffic_happened.happened('p2p/in', len(data))
  39         self.dataReceived2(data)
  40
  41     def dataReceiver(self):
  42         while True:
  43             start = ''
  44             while start != self._message_prefix:
  45                 start = (start + (yield 1))[-len(self._message_prefix):]
  46
  47             command = (yield 12).rstrip('\0')
  48             length, = struct.unpack('<I', (yield 4))
  49             if length > self._max_payload_length:
  50                 print 'length too large'
  51                 continue
  52             checksum = yield 4
  53             payload = yield length
  54
  55             if hashlib.sha256(hashlib.sha256(payload).digest()).digest()[:4] != checksum:
  56                 print 'invalid hash for', self.transport.getPeer().host, repr(command), length, checksum.encode('hex'), hashlib.sha256(hashlib.sha256(payload).digest()).digest()[:4].encode('hex'), payload.encode('hex')
  57                 self.badPeerHappened()
  58                 continue
  59
  60             type_ = getattr(self, 'message_' + command, None)
  61             if type_ is None:
  62                 if p2pool.DEBUG:
  63                     print 'no type for', repr(command)
  64                 continue
  65
  66             try:
  67                 self.packetReceived(command, type_.unpack(payload))
  68             except:
  69                 print 'RECV', command, payload[:100].encode('hex') + ('...' if len(payload) > 100 else '')
  70                 log.err(None, 'Error handling message: (see RECV line)')
  71                 self.transport.loseConnection()
  72
  73     def packetReceived(self, command, payload2):
  74         handler = getattr(self, 'handle_' + command, None)
  75         if handler is None:
  76             if p2pool.DEBUG:
  77                 print 'no handler for', repr(command)
  78             return
  79
  80         if getattr(self, 'connected', True) and not getattr(self, 'disconnecting', False):
  81             handler(**payload2)
  82
  83     def badPeerHappened(self):
  84         self.transport.loseConnection()
  85
  86     def sendPacket(self, command, payload2):
  87         if len(command) >= 12:
  88             raise ValueError('command too long')
  89         type_ = getattr(self, 'message_' + command, None)
  90         if type_ is None:
  91             raise ValueError('invalid command')
  92         #print 'SEND', command, repr(payload2)[:500]
  93         payload = type_.pack(payload2)
  94         if len(payload) > self._max_payload_length:
  95             raise TooLong('payload too long')
  96         data = self._message_prefix + struct.pack('<12sI', command, len(payload)) + hashlib.sha256(hashlib.sha256(payload).digest()).digest()[:4] + payload
  97         self.traffic_happened.happened('p2p/out', len(data))
  98         self.transport.write(data)
  99         return self.paused_var.get_when_satisfies(lambda paused: not paused)
 100
 101     def __getattr__(self, attr):
 102         prefix = 'send_'
 103         if attr.startswith(prefix):
 104             command = attr[len(prefix):]
 105             return lambda **payload2: self.sendPacket(command, payload2)
 106         #return protocol.Protocol.__getattr__(self, attr)
 107         raise AttributeError(attr)