ppauto.py

   1 # -*- coding: utf-8 -*-
   2 # Copyright (c) 2009 Ondřej Súkup
   3 # Parallel Python Software: http://www.parallelpython.com
   4 # Copyright (c) 2005-2009, Vitalii Vanovschi
   5 # All rights reserved.
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions are met:
   8 #    * Redistributions of source code must retain the above copyright notice,
   9 #      this list of conditions and the following disclaimer.
  10 #    * Redistributions in binary form must reproduce the above copyright
  11 #      notice, this list of conditions and the following disclaimer in the
  12 #      documentation and/or other materials provided with the distribution.
  13 #    * Neither the name of the author nor the names of its contributors
  14 #      may be used to endorse or promote products derived from this software
  15 #      without specific prior written permission.
  16 #
  17 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  21 # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  22 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  23 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  25 # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  27 # THE POSSIBILITY OF SUCH DAMAGE.
  28
  29
  30 import socket
  31 import sys
  32 import time
  33 import logging
  34 import _thread
  35
  36 copyright = "Copyright (c) 2009 Ondřej Súkup /n \
  37 Copyright (c) 2005-2009 Vitalii Vanovschi. All rights reserved"
  38 version = "3.0.0"
  39 # broadcast every 10 sec
  40 BROADCAST_INTERVAL = 10
  41
  42
  43 class Discover(object):
  44     """Auto-discovery service class"""
  45
  46     def __init__(self, base, isclient=False):
  47         self.base = base
  48         self.hosts = []
  49         self.isclient = isclient
  50
  51     def run(self, interface_addr, broadcast_addr):
  52         """Starts auto-discovery"""
  53         self.interface_addr = interface_addr
  54         self.broadcast_addr = broadcast_addr
  55         self.bsocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  56         self.bsocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
  57         self.bsocket.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
  58
  59         try:
  60             self.listen()
  61         except:
  62             sys.excepthook(*sys.exc_info())
  63
  64     def broadcast(self):
  65         """Sends a broadcast"""
  66         if self.isclient:
  67             logging.debug("Client sends initial broadcast to (%s, %i)"
  68                     % self.broadcast_addr)
  69             self.bsocket.sendto("C", self.broadcast_addr)
  70         else:
  71             while True:
  72                 logging.debug("Server sends broadcast to (%s, %i)"
  73                         % self.broadcast_addr)
  74                 self.bsocket.sendto("S", self.broadcast_addr)
  75                 time.sleep(BROADCAST_INTERVAL)
  76
  77     def listen(self):
  78         """Listens for broadcasts from other clients/servers"""
  79         logging.debug("Listening (%s, %i)" % self.interface_addr)
  80         s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  81         s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
  82         s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
  83         s.bind(self.interface_addr)
  84
  85         _thread.start_new_thread(self.broadcast, ())
  86
  87         while True:
  88             try:
  89                 message, (host, port) = s.recvfrom(1024)
  90                 remote_address = (host, self.broadcast_addr[1])
  91                 hostid = host + ":" + str(self.broadcast_addr[1])
  92                 logging.debug("Discovered host (%s, %i) message=%c"
  93                         % (remote_address + (message[0], )))
  94                 if not self.base.autopp_list.get(hostid, 0) and self.isclient \
  95                         and message[0] == 'S':
  96                     logging.debug("Connecting to host %s" % (hostid, ))
  97                     _thread.start_new_thread(self.base.connect1,
  98                             remote_address+(False, ))
  99                 if not self.isclient and message[0] == 'C':
 100                     logging.debug("Replying to host %s" % (hostid, ))
 101                     self.bsocket.sendto("S", self.broadcast_addr)
 102             except:
 103                 logging.error("An error has occured during execution of "
 104                         "Discover.listen")
 105                 sys.excepthook(*sys.exc_info())