gajim-plural/src/common/zeroconf.py

import os
import sys

try:
	import avahi, gobject, dbus
except ImportError:
	print "Error: python-avahi and python-dbus need to be installed. No zeroconf support."

try:
	import dbus.glib
except ImportError, e:
	pass

class Zeroconf:
	def __init__(self, name):
		self.domain = None   # specific domain to browse
		self.stype = '_presence._tcp'
		self.port = 5298  # listening port that gets announced
		self.name = name  # service name / username
		self.txt = {}

		self.service_browsers = {}
		self.contacts = {}    # all current local contacts with data
		self.entrygroup = ''
		
	## handlers for dbus callbacks

	# error handler - maybe replace with gui version/gajim facilities
	def print_error_callback(self, err):
		print "Error:", str(err)

	def new_service_callback(self, interface, protocol, name, stype, domain, flags):
		print "Found service '%s' in domain '%s' on %i.%i." % (name, domain, interface, protocol)

		#synchronous resolving
		self.server.ResolveService( int(interface), int(protocol), name, stype, domain, avahi.PROTO_UNSPEC, dbus.UInt32(0), reply_handler=self.service_resolved_callback, error_handler=self.print_error_callback)

	def remove_service_callback(self, interface, protocol, name, stype, domain, flags):
		print "Service '%s' in domain '%s' on %i.%i disappeared." % (name, domain, interface, protocol)
		del self.contacts[(interface, name, domain)]

	def new_service_type(self, interface, protocol, stype, domain, flags):
		# Are we already browsing this domain for this type? 
		if self.service_browsers.has_key((interface, protocol, stype, domain)):
			return

		print "Browsing for services of type '%s' in domain '%s' on %i.%i ..." % (stype, domain, interface, protocol)

		b = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, \
				self.server.ServiceBrowserNew(interface, protocol, \
				stype, domain, dbus.UInt32(0))),avahi.DBUS_INTERFACE_SERVICE_BROWSER)
		b.connect_to_signal('ItemNew', self.new_service_callback)
		b.connect_to_signal('ItemRemove', self.remove_service_callback)

		self.service_browsers[(interface, protocol, stype, domain)] = b

	def new_domain_callback(self,interface, protocol, domain, flags):
		if domain != "local":
			self.browse_domain(interface, protocol, domain)

	def service_resolved_callback(self, interface, protocol, name, stype, domain, host, aprotocol, address, port, txt, flags):
			print "Service data for service '%s' in domain '%s' on %i.%i:" % (name, domain, interface, protocol)
			print "\tHost %s (%s), port %i, TXT data: %s" % (host, address, port, str(avahi.txt_array_to_string_array(txt)))

			self.contacts[(interface, name, domain)] = (interface, name, protocol, domain, host, address, port, txt)


	def service_added_callback(self):
		print "Service successfully added"
	
	def service_committed_callback(self):
		print "Service successfully committed"
		
	def service_updated_callback(self):
		print "Service successfully updated"

	def service_add_fail_callback(self, err):
		print "Error while adding service:", str(err)
		self.name = self.server.GetAlternativeServiceName(self.name)
		self.create_service()
	
	def server_state_changed_callback(self, state, error):
		print "server.state %s" % state
		if state == avahi.SERVER_RUNNING:
			self.create_service()
		elif state == avahi.SERVER_COLLISION:
			self.entrygroup.Reset()
#		elif state == avahi.CLIENT_FAILURE:           # TODO: add error handling (avahi daemon dies...?)
		
	def entrygroup_state_changed_callback(self, state, error):
		# the name is already present, so ...
		if state == avahi.ENTRY_GROUP_COLLISION:
			print "Collision with existing service of name %s" % self.name
			# ... get a new one and recreate the service
			self.name = self.server.GetAlternativeServiceName(self.name)
			self.create_service()
#		elif state == avahi.ENTRY_GROUP_FAILURE:

	def create_service(self):
		if self.entrygroup == '':
			# create an EntryGroup for publishing
			self.entrygroup = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, self.server.EntryGroupNew()), avahi.DBUS_INTERFACE_ENTRY_GROUP)
			self.entrygroup.connect_to_signal('StateChanged', self.entrygroup_state_changed_callback)
				
		self.txt[('port.p2pj')] = self.port
		self.txt[('version')] = 1
		self.txt[('textvers')] = 1

		print "Publishing service '%s' of type %s" % (self.name, self.stype)
		self.entrygroup.AddService(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, dbus.UInt32(0), self.name, self.stype, '', '', self.port, avahi.dict_to_txt_array(self.txt), reply_handler=self.service_added_callback, error_handler=self.service_add_fail_callback)
		self.entrygroup.Commit(reply_handler=self.service_committed_callback, error_handler=self.print_error_callback)
		
	def publish(self):
		state = self.server.GetState()

		if state == avahi.SERVER_RUNNING:
			self.create_service()
		
	def remove_announce(self):
		self.entrygroup.Reset()
		self.entrygroup.Free()

	def browse_domain(self, interface, protocol, domain):
		self.new_service_type(interface, protocol, self.stype, domain, '')
	
	# connect to dbus
	def connect(self):
		self.bus = dbus.SystemBus()
		self.server = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, \
			avahi.DBUS_PATH_SERVER), avahi.DBUS_INTERFACE_SERVER)

		self.server.connect_to_signal('StateChanged', self.server_state_changed_callback)
		
		# start browsing
		if self.domain is None:
			# Explicitly browse .local
			self.browse_domain(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, "local")

			# Browse for other browsable domains
			db = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, \
					self.server.DomainBrowserNew(avahi.IF_UNSPEC, \
					avahi.PROTO_UNSPEC, '', avahi.DOMAIN_BROWSER_BROWSE,\
					dbus.UInt32(0))), avahi.DBUS_INTERFACE_DOMAIN_BROWSER)
			db.connect_to_signal('ItemNew', self.new_domain_callback)
		else:
			# Just browse the domain the user wants us to browse
			self.browse_domain(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, domain)

#   def disconnect:
#       necessary ?

	# refresh data manually - really ok or too much traffic?
	def resolve_all(self):
		for key in contacts.keys():
			self.server.ResolveService( int(key.interface), int(key.protocol), key.name, \
				self.stype, key.domain, avahi.PROTO_UNSPEC, dbus.UInt32(0),\
				reply_handler=self.service_resolved_callback, error_handler=self.print_error_callback)

	def get_contacts(self):
		self.resolve_all
		return self.contacts

	def set_status(self, status):
		self.txt[('status')] = status
		txt = avahi.dict_to_txt_array(self.txt)

		self.entrygroup.UpdateServiceTxt(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, dbus.UInt32(0), self.name, self.stype,'', txt, reply_handler=self.service_updated_callback, error_handler=self.print_error_callback)
#		self.entrygroup.Commit()         # TODO: necessary?

# END Zeroconf

'''
def main():

	zeroconf = Zeroconf('foo')
	zeroconf.connect()
	zeroconf.txt[('last')] = 'foo'
	zeroconf.publish()
	zeroconf.set_status('avail')
	
	try:
		gobject.MainLoop().run()
	except KeyboardInterrupt, k:
		pass

if __name__ == "__main__":
	main()                                         
'''