Viewing file:  dnssdresolve.py (4.38 KB) -rw-r--r--
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#!/usr/bin/env python
## Copyright (C) 2010 Red Hat, Inc.
## Authors:
## Tim Waugh <twaugh@redhat.com>
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
import dbus
from debug import *
class DNSSDHostNamesResolver:
def __init__ (self, devices):
self._devices = devices
self._unresolved = len (devices)
self._device_uri_by_name = {}
debugprint ("+%s" % self)
def __del__ (self):
debugprint ("-%s" % self)
def resolve (self, reply_handler):
self._reply_handler = reply_handler
bus = dbus.SystemBus ()
if not bus:
reply_handler ([])
del self._devices
del self._reply_handler
return
for uri, device in self._devices.iteritems ():
if not uri.startswith ("dnssd://"):
self._unresolved -= 1
continue
# We need to resolve the DNS-SD hostname in order to
# compare with other network devices.
p = uri[8:].find ("/")
if p == -1:
hostname = uri[8:]
else:
hostname = uri[8:8+p]
elements = hostname.split (".")
if len (elements) != 4:
self._resolved ()
continue
name, stype, protocol, domain = elements
stype += "." + protocol # e.g. _printer._tcp
try:
obj = bus.get_object ("org.freedesktop.Avahi", "/")
server = dbus.Interface (obj,
"org.freedesktop.Avahi.Server")
self._device_uri_by_name[(name, stype, domain)] = uri
debugprint ("Resolving address for %s" % hostname)
server.ResolveService (-1, -1,
name, stype, domain,
-1, 0,
reply_handler=self._reply,
error_handler=lambda e:
self._error (uri, e))
except dbus.DBusException, e:
debugprint ("Failed to resolve address: %s" % e)
self._resolved ()
def _resolved (self):
self._unresolved -= 1
if self._unresolved == 0:
debugprint ("All addresses resolved")
self._reply_handler (self._devices)
del self._devices
del self._reply_handler
def _reply (self, interface, protocol, name, stype, domain,
host, aprotocol, address, port, txt, flags):
uri = self._device_uri_by_name[(name, stype, domain)]
self._devices[uri].address = address
debugprint ("%s is at %s" % (uri, address))
self._resolved ()
def _error (self, uri, error):
debugprint ("Error resolving %s: %s" % (uri, error))
self._resolved ()
if __name__ == '__main__':
class Device:
def __repr__ (self):
try:
return "<Device @ %s>" % self.address
except:
return "<Device>"
devices = {"dnssd://dlk-08E206-P1._printer._tcp.local/": Device(),
"dnssd://foo._printer._tcp.local/": Device()}
from dbus.glib import DBusGMainLoop
DBusGMainLoop (set_as_default=True)
class Test:
def __init__ (self, loop, devices):
self._loop = loop
self._devices = devices
def run (self):
r = DNSSDHostNamesResolver (self._devices)
r.resolve (reply_handler=self.reply)
return False
def reply (self, *args):
print args
self._loop.quit ()
import gobject
loop = gobject.MainLoop ()
set_debugging (True)
gobject.idle_add (Test (loop, devices).run)
loop.run ()
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